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  • 1. Bao, J.
    et al.
    Ma, Z.
    Karagiannidis, G. K.
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Zhu, Z.
    Joint Multiuser Detection of Multidimensional Constellations over Fading Channels2017Ingår i: IEEE Transactions on Communications, ISSN 0090-6778, E-ISSN 1558-0857, Vol. 65, nr 1, s. 161-172, artikel-id 7723894Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We investigate the error performance of multidimensional constellations in the multiple access and broadcast channels. More specifically, we provide closed-form expressions for the pairwise error probability (PEP) of the joint maximum likelihood detection, for multiuser signaling in the presence of additive white Gaussian noise and Rayleigh fading. Arbitrary numbers of users and multidimensional signal sets are assumed, while the provided formula for the PEP is a function of the dimension-wise distances of the multidimensional constellation. Furthermore, a useful upper bound on the average symbol error probability is also obtained through the union bound. The analysis is applied to the sparse code multiple access systems. The analytical results are validated successfully through simulations, and show their importance in the multidimensional constellation design.

  • 2. Bao, J.
    et al.
    Ma, Z.
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Teknisk informationsvetenskap. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Tsiftsis, T. A.
    Zhu, Z.
    Performance analysis of uplink sparse code multiple access with iterative multiuser receiver2017Ingår i: 2017 IEEE International Conference on Communications, ICC 2017, Institute of Electrical and Electronics Engineers (IEEE), 2017, artikel-id 7996537Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper investigates the asymptotic performance of bit-interleaved coded modulation (BICM) with iterative multiuser detection and decoding in uplink sparse code multiple access (SCMA) systems. The extrinsic information transfer (EXIT) characteristics analysis of the joint multiuser detector for SCMA is provided, and shows that the average detection reliability for multiple users converges to the single-user case, if ideal feedback from the decoder is available to the detector. We develop a tight analytical bound on the convolutionally encoded bit-error rate (BER) for independent Rayleigh fadings, based on the single-user bound with arbitrary multidimensional constellations. Moreover, we analyze the achievable coding and diversity gains of the SCMA-BICM system with iterative receiver. Simulations are carried out to verify the effectiveness of the analysis.

  • 3.
    Bao, Jinchen
    et al.
    Southwest Jiaotong Univ, Prov Key Lab Informat Coding & Transmiss, Chengdu 611756, Sichuan, Peoples R China..
    Ma, Zheng
    Southwest Jiaotong Univ, Prov Key Lab Informat Coding & Transmiss, Chengdu 611756, Sichuan, Peoples R China..
    Xiao, Ming
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Teknisk informationsvetenskap.
    Tsiftsis, Theodoros A.
    Jinan Univ, Sch Elect & Informat Engn, Zhuhai 519070, Peoples R China..
    Zhu, Zhongliang
    Southwest Jiaotong Univ, Prov Key Lab Informat Coding & Transmiss, Chengdu 611756, Sichuan, Peoples R China..
    Bit-Interleaved Coded SCMA With Iterative Multiuser Detection: Multidimensional Constellations Design2018Ingår i: IEEE Transactions on Communications, ISSN 0090-6778, E-ISSN 1558-0857, Vol. 66, nr 11, s. 5292-5304Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper investigates the constellation/codebook design of a promising uplink multiple access technique, sparse code multiple access (SCMA), proposed for the fifth generation mobile networks. The application of bit-interleaved coded modulation with iterative multiuser detection is considered for uplink SCMA over fading channels. Extrinsic information transfer chart is used to aid the analysis and the design of multidimensional constellations, and the design criteria for multidimensional constellations and labelings optimization are thus established. Furthermore, a new and simple approach of multi-stage optimization for the multidimensional constellation design is proposed for SCMA, to improve the bit-error rate performance and alleviate the complexity of turbo multiuser detection. Numerical and simulation results are also provided to demonstrate the performance and verify the efficiency of the proposed scheme, compared with the state of the art.

  • 4. Bao, Jinchen
    et al.
    Ma, Zheng
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Zhu, Zhongliang
    Error Performance of Sparse Code Multiple Access Networks with Joint ML Detection2016Ingår i: 2016 IEEE 83RD VEHICULAR TECHNOLOGY CONFERENCE (VTC SPRING), IEEE, 2016Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper investigates error performance of sparse code multiple access (SCMA) networks with multiple access channels (MAC) and broadcast channels (BC). We give the closedform expression for the pairwise error probability (PEP) of joint maximum likelihood (ML) detection for multiuser signals over additive white Gaussian noise (AWGN) and Rayleigh fading channels with an arbitrary number of users and multidimensional codebooks. An upper bound for the average symbol error rate (SER) is calculated. The bound is tight in both AWGN channel and Rayleigh fading channels for high SNR regions. The analytical bounds are compared with simulations, and the results confirm the effectiveness of the analysis for both AWGN and Rayleigh fading channels.

  • 5. Cao, CongZhe
    et al.
    ZeSong, Fei
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    GaiShi, Huang
    ChengWen, Xing
    JingMing, Kuang
    An extended packetization-aware mapping algorithm for scalable video coding in finite-length fountain codes2013Ingår i: Science China Information Sciences, ISSN 1674-733X, Vol. 56, nr 4, s. 042311-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We propose an extended packetization-aware mapping algorithm based on fountain codes to enhance video stream performance which is vulnerable to packet losses. By properly utilizing the proposed algorithm in finite-length cases, the edges connecting to a source symbol are scattered over multiple encoding packets so that the decoding probabilities are increased. Furthermore, an improved degree distribution is designed to obtain better decoding probabilities. Numerical results, it is confirmed that the proposed algorithm in finite-length cases can augment decoding probabilities and the improved degree distribution can increase peak signal-to-noise ratio (PSNR) of scalable video coding (SVC) in a hostile communication environment.

  • 6.
    Cui, Yaping
    et al.
    Southwest Jiaotong Univ, Sch Informat Sci & Technol, Chengdu 610031, Sichuan, Peoples R China.;Chongqing Univ Posts & Telecommun, Sch Commun & Informat Engn, Chongqing 400065, Peoples R China..
    Fang, Xuming
    Southwest Jiaotong Univ, Sch Informat Sci & Technol, Chengdu 610031, Sichuan, Peoples R China..
    Fang, Yuguang
    Univ Florida, Dept Elect & Comp Engn, Gainesville, FL 32611 USA..
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Optimal Nonuniform Steady mmWave Beamforming for High-Speed Railway2018Ingår i: IEEE Transactions on Vehicular Technology, ISSN 0018-9545, E-ISSN 1939-9359, Vol. 67, nr 5, s. 4350-4358Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Using higher frequency bands (e.g., millimeter waves) to provide higher data rate is an effective way to eliminate performance bottleneck for future wireless networks, particularly for cellular networks based high-speed railway (HSR) wireless communication systems. However, higher frequency bands suffer from significant path loss and narrow-beam coverage, which pose serious challenges in cellular networks, especially under the HSR scenario. Meanwhile, as one of the key performance indexes of ultrareliable and low-latency communications in 5G systems, network reliability should be guaranteed to provide steady reliable data transmission along the railway, especially when safety-critical railway signaling information is delivered. In this paper, we propose a novel beamforming scheme, namely, optimal nonuniform steady mmWave beamforming, to guarantee the network reliability under an interleaved redundant coverage architecture for future HSR wireless systems. Moreover, we develop a bisection-based beam boundary determination (BBBD) method to determine the service area of each predefined RF beam. Finally, we demonstrate that the proposed optimal nonuniform steady mmWave beamforming can provide steady reliable data transmissions along the railway, and the network reliability requirements can be guaranteed when the proposed BBBD method is used. We expect that our optimal nonuniform steady mmWave beamforming provides a promising solution for future HSR wireless systems.

  • 7.
    Dai, Bin
    et al.
    Southwest Jiaotong Univ, Sch Informat Sci & Technol, Chengdu 610031, Sichuan, Peoples R China.;Southeast Univ, Natl Mobile Commun Res Lab, Nanjing 210018, Peoples R China..
    Ma, Zheng
    Southwest Jiaotong Univ, Sch Informat Sci & Technol, Chengdu 610031, Sichuan, Peoples R China..
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Tang, Xiaohu
    Southwest Jiaotong Univ, Sch Informat Sci & Technol, Chengdu 610031, Sichuan, Peoples R China..
    Fan, Pingzhi
    Southwest Jiaotong Univ, Sch Informat Sci & Technol, Chengdu 610031, Sichuan, Peoples R China..
    Secure Communication Over Finite State Multiple-Access Wiretap Channel With Delayed Feedback2018Ingår i: IEEE Journal on Selected Areas in Communications, ISSN 0733-8716, E-ISSN 1558-0008, Vol. 36, nr 4, s. 723-736Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Recently, it has been shown that the time-varying multiple-access channel (MAC) with perfect channel state information (CSI) at the receiver and delayed feedback CSI at the transmitters can be modeled as the finite state MAC (FS-MAC) with delayed state feedback, where the time variation of the channel is characterized by the statistics of the underlying state process. To study the fundamental limit of the secure transmission over multi-user wireless communication systems, we re-visit the FS-MAC with delayed state feedback by considering an external eavesdropper, which we call the finite state multipleaccess wiretap channel (FS-MAC-WT) with delayed feedback. The main contribution of this paper is to show that taking full advantage of the delayed channel output feedback helps to increase the secrecy rate region of the FS-MAC-WT with delayed state feedback. Moreover, by a degraded Gaussian fading example, we show the effects of feedback delay and channel memory on the secrecy sum rate of the FS-MAC-WT with delayed feedback.

  • 8. DengSheng, Lin
    et al.
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    ShaoQian, Li
    Packet combining based on cross-packet coding2013Ingår i: Science China Information Sciences, ISSN 1674-733X, Vol. 56, nr 2, s. 022302-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We propose a packet combining scheme of using cross-packet coding. With the coding scheme, one redundant packet can be used to ensure the error-correction of multiple source packets. Thus, the proposed scheme can increase the code rate. Moreover, the proposed coding scheme has also advantages of decoding complexity, reducing undetectable errors (by the proposed low-complexity decoder) and flexibility (applicable to channels with and without feedback). Theoretical analysis under the proposed low-complexity decoding algorithm is given to maximize the code rate by optimizing the number of source packets. Finally, we give numerical results to demonstrate the advantages of the proposed scheme in terms of code rates compared to the traditional packet combining without coding or ARQ (automatic repeat-request) techniques.

  • 9.
    Du, Jinfeng
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Larsson, Erik G.
    Division for Communication Systems, Linköping University.
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Skoglund, Mikael
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Optimal Symbol-by-Symbol Costa Precoding for a Relay-Aided Downlink Channel2011Ingår i: IEEE Transactions on Communications, ISSN 0090-6778, E-ISSN 1558-0857, Vol. 59, nr 8, s. 2274-2284Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this article, we consider practical approaches to Costa precoding (also known as dirty paper coding). Specifically, we propose a symbol-by-symbol scheme for cancellation of interference known at the transmitter in a relay-aided downlink channel. For finite-alphabet signaling and interference, we derive the optimal (in terms of maximum mutual information) modulator under a given power constraint. A sub-optimal modulator is also proposed by formulating an optimization problem that maximizes the minimum distance of the signal constellation, and this non-convex optimization problem is approximately solved by semi-definite relaxation. For the case of binary signaling with binary interference, we obtain a closed-form solution for the sub-optimal modulator, which only suffers little performance degradation compared to the optimal modulator in the region of interest. For more general signal constellations and more general interference distributions, we propose an optimized Tomlinson-Harashima precoder (THP), which uniformly outperforms conventional THP with heuristic parameters. Bit-level simulation shows that the optimal and sub-optimal modulators can achieve significant gains over the THP benchmark as well as over non-Costa reference schemes, especially when the power of the interference is larger than the power of the noise.

  • 10.
    Du, Jinfeng
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. MIT, Cambridge, USA.
    Medard, Muriel
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Skoglund, Mikael
    KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre. KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Scalable Capacity Bounding Models for Wireless Networks2016Ingår i: IEEE Transactions on Information Theory, ISSN 0018-9448, E-ISSN 1557-9654, Vol. 62, nr 1, s. 208-229Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The framework of network equivalence theory developed by Koetter et al. introduces a notion of channel emulation to construct noiseless networks as upper (respectively, lower) bounding models, which can be used to calculate the outer (respectively, inner) bounds for the capacity region of the original noisy network. Based on the network equivalence framework, this paper presents scalable upper and lower bounding models for wireless networks with potentially many nodes. A channel decoupling method is proposed to decompose wireless networks into decoupled multiple-access channels and broadcast channels. The upper bounding model, consisting of only point-to-point bit pipes, is constructed by first extending the one-shot upper bounding models developed by Calmon et al. and then integrating them with network equivalence tools. The lower bounding model, consisting of both point-to-point and point-to-points bit pipes, is constructed based on a two-step update of the lower bounding models to incorporate the broadcast nature of wireless transmission. The main advantages of the proposed methods are their simplicity and the fact that they can be extended easily to large networks with a complexity that grows linearly with the number of nodes. It is demonstrated that the resulting upper and lower bounds can approach the capacity in some setups.

  • 11.
    Du, Jinfeng
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Médard, Muriel
    Department of Electrical Engineering and Computer Science, MIT.
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Skoglund, Mikael
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Lower bounding models for wireless networks2013Ingår i: Proceedings of IEEE International Symposium on Information Theory, 2013, IEEE conference proceedings, 2013, s. 1456-1460Konferensbidrag (Refereegranskat)
    Abstract [en]

    Motivated by the framework of network equivalencetheory [1], [2], we present capacity lower bounding models forwireless networks by construction of noiseless networks whichcan be used to calculate an inner bound for the correspondingwireless network. We first extend the “one-shot” lower boundingmodel [6] to many-user scenarios, and then propose a two-stepupdate of the one-shot models to incorporate the broadcast natureof wireless transmission. The main advantage of the proposedlower bounding method is its simplicity and the fact that it can beeasily extended to larger networks. We demonstrate by examplesthat the resulting lower bounds can even approach the capacityin some setups.

  • 12.
    Du, Jinfeng
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre. Research Lab of Electronics, MIT.
    Médard, Muriel
    Department of Electrical Engineering and Computer Science, MIT.
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Skoglund, Mikael
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Scalable capacity bounding models for wireless networksManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Based on the framework of network equivalence theory developed by Koetter et al., this paper presents scalable capacity upper and lower bounding models for wireless networks by construction of noiseless networks that can be used to calculate outer and inner bounds, respectively, for the original networks. A channel decoupling method is proposed to decompose wireless networks into point-to-point channels, and (potentially) coupled multiple-access channels (MACs) and broadcast channels (BCs). The upper bounding model, consisting of only point-to-point bit-pipes, is constructed by firstly extending the "one-shot" bounding models developed by Calmon et al. and then integrating them with network equivalence tools. The lower bounding model, consisting of both point-to-point and point-to-points bit-pipes, is constructed based on a two-step update of the one-shot models to incorporate the broadcast nature of wireless transmission. The main advantages of the proposed methods are their simplicity and the fact that they can be extended easily to large networks with a complexity that grows linearly with the number of nodes. It is demonstrated that the gap between the resulting upper and lower bounds is usually not large, and they can approach the capacity in some setups.

  • 13.
    Du, Jinfeng
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre. Research Lab of Electronics, Massachusetts Institute of Technology.
    Médard, Muriel
    Department of Electrical Engineering and Computer Science, MIT.
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Skoglund, Mikael
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Scalable upper bounding models for wireless networks2014Ingår i: Proceedings of IEEE International Symposium on Information Theory, IEEE conference proceedings, 2014, s. 241-245Konferensbidrag (Refereegranskat)
    Abstract [en]

    The framework of network equivalence theory developed by Koetter et al. introduces a notion of channel emulation to construct noiseless networks as upper/lower bounding models for the original noisy network. This paper presents scalable upper bounding models for wireless networks, by firstly extending the ``one-shot'' bounding models developed by Calmon et al. and then integrating them with network equivalence tools. A channel decoupling method is proposed to decompose wireless networks into decoupled multiple-access channels (MACs) and broadcast channels (BCs). The main advantages of the proposed method is its simplicity and the fact that it can be extended easily to large networks with a complexity that grows linearly with the number of nodes. It is demonstrated that the resulting upper bounds can approach the capacity in some setups.

  • 14.
    Du, Jinfeng
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Skoglund, Mikael
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Capacity Bounds for Backhaul-Supported Wireless Multicast Relay Networks with Cross-Links2011Ingår i: IEEE INTERNATIONAL CONFERENCE ON COMMUNICATIONS (ICC), 2011, NEW YORK: IEEE conference proceedings, 2011, s. 1-5Konferensbidrag (Refereegranskat)
    Abstract [en]

    We investigate the capacity bounds for a wireless multicast relay network where two sources simultaneously multicast to two destinations through Gaussian channels with the help of a full-duplex relay node. All the individual channel gains are assumed to be time-invariant and known to every nodes in the network. The transmissions from two sources and from the relay use the same channel resource (i.e. co-channel transmission) and the two source nodes are connected with an orthogonal error-free backhaul. This multicast relay network is generic in the sense that it can be extended to more general networks by tuning the channel gains within the range [0, ∞). By extending the proof of the converse developed by Cover and El Gamal for the Gaussian relay channel, we characterize the cut-set bound for this multicast relay network. We also present a lower bound by using decoding-and-forward relaying combined with network beam-forming.

  • 15.
    Du, Jinfeng
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Skoglund, Mikael
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Capacity bounds for relay-aided wireless multiple multicast with backhaul2010Ingår i: 2010 International Conference on Wireless Communications and Signal Processing, WCSP 2010, NEW YORK: IEEE conference proceedings, 2010, s. 1-5Konferensbidrag (Refereegranskat)
    Abstract [en]

    We investigate the capacity bounds for relay-aided two-source two-destination wireless networks with backhaul support between source nodes. Each source multicasts its own message to all destinations with the help of an intermediate relay node, which is full-duplex and shared by both sources. We are aiming to characterize the capacity region of this model given discrete memoryless Gaussian channels. We establish three capacity upper bounds by relaxing the cut-set bound, and by extending two capacity bounds originally derived for MIMO relay channels. We also present one lower bound by using decoding-and-forward relaying combined with network beam-forming.

  • 16.
    Du, Jinfeng
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Skoglund, Mikael
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Cooperative Network Coding Strategies for Wireless Relay Networks with Backhaul2011Ingår i: IEEE Transactions on Communications, ISSN 0090-6778, E-ISSN 1558-0857, Vol. 59, nr 9, s. 2502-2514Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We investigate cooperative network coding strategies for relay-aided two-source two-destination wireless networks with a backhaul connection between the source nodes. Each source multicasts information to all destinations using a shared relay. We study cooperative strategies based on different network coding schemes, namely, finite field and linear network coding, and lattice coding. To further exploit the backhaul connection, we also propose network coding based beamforming. We measure the performance in term of achievable rates over Gaussian channels, and observe significant gains over benchmark schemes. We derive the achievable rate regions for these schemes and find the cut-set bound for our system. We also show that the cut-set bound can be achieved by network coding based beamforming when the signal-to-noise ratios lie in the sphere defined by the source-relay and relay-destination channel gains.

  • 17.
    Du, Jinfeng
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre. KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Skoglund, Mikael
    KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre. KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Cooperative strategies for relay-aided multi-cell wireless networks with backhaul2010Ingår i: 2010 IEEE Information Theory Workshop, ITW 2010 - Proceedings, NEW YORK: IEEE conference proceedings, 2010, s. 1-5Konferensbidrag (Refereegranskat)
    Abstract [en]

    We investigate cooperative strategies for relay-aided multi-source multi-destination wireless networks with backhaul support. Each source multicasts information to all destinations using a shared relay. We study cooperative strategies based on different network coding (NC) schemes, namely, finite field NC (FNC), linear NC (LNC), and lattice coding. To further exploit the backhaul connection, we also propose NC-based beam-forming (NBF). We measure the performance in term of achievable rates over Gaussian channels and observe significant gains over a benchmark scheme. The benefit of using backhaul is also clearly demonstrated in most of scenarios.

  • 18.
    Du, Jinfeng
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Skoglund, Mikael
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Médard, Muriel
    Department of Electrical Engineering and Computer Science, MIT.
    Wireless multicast relay networks with limited-rate source-conferencing2013Ingår i: IEEE Journal on Selected Areas in Communications, ISSN 0733-8716, E-ISSN 1558-0008, Vol. 31, nr 8, s. 1390-1401Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We investigate capacity bounds for a wireless multicast relay network where two sources simultaneously multicast to two destinations with the help of a full-duplex relay node. The two sources and the relay use the same channel resources (i.e. co-channel transmission). We assume Gaussian channels with time-invariant channel gains which are known by all nodes. The two source nodes are connected by orthogonal limited-rate error-free conferencing links. By extending the proof of the converse for the Gaussian relay channel and introducing two lemmas on conditional (co-)variance, we present two genie-aided outer bounds of the capacity region for this multicast relay network. We extend noisy network coding to use source cooperation with the help of the theory of network equivalence. We also propose a new coding scheme, partial-decode-and- forward based linear network coding, which is essentially a hybrid scheme utilizing rate-splitting and messages conferencing at the source nodes, partial decoding and linear network coding at the relay, and joint decoding at each destination. A low-complexity alternative scheme, analog network coding based on amplify-and-forward relaying, is also investigated and shown to benefit greatly from the help of the conferencing links and can even outperform noisy network coding when the coherent combining gain is dominant.

  • 19.
    Du, Jinfeng
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Skoglund, Mikael
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Shamai (Shitz), Shlomo
    Technion - Israel Institute of Technology.
    Short-Message Noisy Network Coding with Partial Source Cooperation2012Ingår i: Information Theory Workshop (ITW), 2012 IEEE, IEEE conference proceedings, 2012, s. 144-147Konferensbidrag (Refereegranskat)
    Abstract [en]

    Noisy network coding (NNC) has been shown to outperform standard compress-and-forward (CF) in networks with multiple relays and/or multiple destinations. Recently, short-message noisy network coding (SNNC) has been proved to achieve the same rate region as NNC for independent sources but with significantly reduced encoding delay and decoding complexity. In this paper, we show that when partial cooperation between source nodes is possible, by performing rate-splitting, message exchange, and superposition coding with proper power allocation at the source nodes, SNNC can achieve a strictly larger rate region than NNC. The gain comes from coherent combining at all the receiving nodes.

  • 20.
    Du, Rong
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik.
    Fischione, Carlo
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Flowing with the water: On optimal monitoring of water distribution networks by mobile sensors2016Konferensbidrag (Refereegranskat)
  • 21.
    Du, Rong
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik.
    Fischione, Carlo
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik.
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Lifetime Maximization for Sensor Networks with Wireless Energy Transfer2016Ingår i: 2016 IEEE International Conference on Communications, ICC 2016, Institute of Electrical and Electronics Engineers (IEEE), 2016, s. 20-25, artikel-id 7510602Konferensbidrag (Refereegranskat)
    Abstract [en]

    In Wireless Sensor Networks (WSNs), to supply energy to the sensor nodes, wireless energy transfer (WET) is a promising technique. One of the most efficient procedures to transfer energy to the sensor nodes consists in using a sharp wireless energy beam from the base station to each node at a time. A natural fundamental question is what is the lifetime ensured by WET and how to maximize the network lifetime by scheduling the transmissions of the energy beams. In this paper, such a question is addressed by posing a new lifetime maximization problem for WET enabled WSNs. The binary nature of the energy transmission process introduces a binary constraint in the optimization problem, which makes challenging the investigation of the fundamental properties of WET and the computation of the optimal solution. The sufficient condition for which the WET makes WSNs immortal is established as function of the WET parameters. When such a condition is not met, a solution algorithm to the maximum lifetime problem is proposed. The numerical results show that the lifetime achieved by the proposed algorithm increases by about 50% compared to the case without WET, for a WSN with a small to medium size number of nodes. This suggests that it is desirable to schedule WET to prolong lifetime of WSNs having small or medium network sizes.

  • 22.
    Du, Rong
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Fischione, Carlo
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Poster: On the Immortality of Wireless Sensor Networks by Wireless Energy Transfer - A Node Deployment Perspective2017Ingår i: Proceedings of International Conference on Embedded Wireless Systems and Networks, 2017Konferensbidrag (Refereegranskat)
    Abstract [en]

    The lifetime of wireless sensor networks (WSNs) can be substantially extended by transferring energy wirelessly to the sensor nodes. In this poster, a wireless energy transfer (WET) enabled WSN is presented, where a base station transfers energy wirelessly to the sensor nodes that are deployed in several regions of interest, to supply them with energy to sense and to upload data. The WSN lifetime can be extended by deploying redundant sensor nodes, which allows the implementation of duty-cycling mechanisms to reduce nodes' energy consumption. In this context, a problem on sensor node deployment naturally arises, where one needs to determine how many sensor nodes to deploy in each region such that the total number of nodes is minimized, and the WSN is immortal. The problem is formulated as an integer optimization, whose solution is challenging due to the binary decision variables and a non-linear constraint. A greedy-based algorithm is proposed to achieve the optimal solution of such deployment problem. It is argued  that such scheme can be used in monitoring systems in smart cities, such as smart buildings and water lines.

  • 23.
    Du, Rong
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik.
    Gkatzikis, Lazaros
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik.
    Fischione, Carlo
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik.
    Xiag, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Energy Efficient Sensor Activation for Water Distribution Networks Based on Compressive Sensing2015Ingår i: IEEE Journal on Selected Areas in Communications, ISSN 0733-8716, E-ISSN 1558-0008, Vol. 33, nr 12, s. 2997-3010Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The recent development of low cost wireless sensors enables novel internet-of-things (IoT) applications, such as the monitoring of water distribution networks. In such scenarios, the lifetime of the wireless sensor network (WSN) is a major concern, given that sensor node replacement is generally inconvenient and costly. In this paper, a compressive sensing-based scheduling scheme is proposed that conserves energy by activating only a small subset of sensor nodes in each timeslot to sense and transmit. Compressive sensing introduces a cardinality constraint that makes the scheduling optimization problem particularly challenging. Taking advantage of the network topology imposed by the IoT water monitoring scenario, the scheduling problem is decomposed into simpler subproblems, and a dynamic-programming-based solution method is proposed. Based on the proposed method, a solution algorithm is derived, whose complexity and energy-wise performance are investigated. The complexity of the proposed algorithm is characterized and its performance is evaluated numerically via an IoT emulator of water distribution networks. The analytical and numerical results show that the proposed algorithm outperforms state-of-the-art approaches in terms of energy consumption, network lifetime, and robustness to sensor node failures. It is argued that the derived solution approach is general and it can be potentially applied to more IoT scenarios such as WSN scheduling in smart cities and intelligent transport systems.

  • 24.
    Du, Rong
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik.
    Gkatzikis, Lazaros
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik.
    Fischione, Carlo
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik.
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Energy efficient monitoring of water distribution networks via compressive sensing2015Ingår i: 2015 IEEE International Conference on Communications (ICC), IEEE conference proceedings, 2015, Vol. 2015, s. 6681-6686Konferensbidrag (Refereegranskat)
    Abstract [en]

    The recent development of low cost wireless sensors enables water monitoring through dense wireless sensor networks (WSN). Sensor nodes are battery powered devices, and hence their limited energy resources have to be optimally managed. The latest advancements in compressive sensing (CS) provide ample promise to increase WSNs lifetime by limiting the amount of measurements that have to be collected. Additional energy savings can be achieved through CS-based scheduling schemes that activate only a limited number of sensors to sense and transmit their measurements, whereas the rest are turned off. The ultimate objective is to maximize network lifetime without sacrificing network connectivity and monitoring performance. This problem can be approximated by an energy balancing approach that consists of multiple simpler subproblems, each of which corresponds to a specific time period. Then, the sensors that should be activated within a given period can be optimally derived through dynamic programming. The complexity of the proposed CS-based scheduling scheme is characterized and numerical evaluation reveals that it achieves comparable monitoring performance by activating only a fraction of the sensors.

  • 25.
    Du, Rong
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Nätverk och systemteknik.
    Gkatzikis, Lazaros
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Reglerteknik.
    Fischione, Carlo
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Nätverk och systemteknik.
    Xiao, Ming
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Teknisk informationsvetenskap.
    On Maximizing Sensor Network Lifetime by Energy Balancing2018Ingår i: IEEE Transactions on Control of Network Systems, ISSN 2325-5870, Vol. 5, nr 3Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Many physical systems, such as water/electricity distribution networks, are monitored by battery-powered wireless-sensor networks (WSNs). Since battery replacement of sensor nodes is generally difficult, long-term monitoring can be only achieved if the operation of the WSN nodes contributes to long WSN lifetime. Two prominent techniques to long WSN lifetime are 1) optimal sensor activation and 2) efficient data gathering and forwarding based on compressive sensing. These techniques are feasible only if the activated sensor nodes establish a connected communication network (connectivity constraint), and satisfy a compressive sensing decoding constraint (cardinality constraint). These two constraints make the problem of maximizing network lifetime via sensor node activation and compressive sensing NP-hard. To overcome this difficulty, an alternative approach that iteratively solves energy balancing problems is proposed. However, understanding whether maximizing network lifetime and energy balancing problems are aligned objectives is a fundamental open issue. The analysis reveals that the two optimization problems give different solutions, but the difference between the lifetime achieved by the energy balancing approach and the maximum lifetime is small when the initial energy at sensor nodes is significantly larger than the energy consumed for a single transmission. The lifetime achieved by energy balancing is asymptotically optimal, and that the achievable network lifetime is at least 50% of the optimum. Analysis and numerical simulations quantify the efficiency of the proposed energy balancing approach.

  • 26.
    Du, Rong
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Nätverk och systemteknik.
    Santi, Paolo
    Xiao, Ming
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Teknisk informationsvetenskap.
    Vasilakos, Athanasios
    Fischione, Carlo
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Nätverk och systemteknik.
    The sensable city: A survey on the deployment and management for smart city monitoringIngår i: IEEE Communications Surveys and Tutorials, ISSN 1553-877X, E-ISSN 1553-877XArtikel i tidskrift (Refereegranskat)
    Abstract [en]

    In last two decades, various monitoring systems have been designed and deployed in urban environments, toward the realization of the so called smart cities. Such systems are based on both dedicated sensor nodes, and ubiquitous but not dedicated devices such as smart phones and vehicles' sensors. When we design sensor network monitoring systems for smart cities, we have two essential problems: node deployment and sensing management. These design problems are challenging, due to large urban areas to monitor, constrained locations for deployments, and heterogeneous type of sensing devices. There is a vast body of literature from different disciplines that have addressed these challenges. However, we do not have yet a comprehensive understanding and sound design guidelines. This paper addresses such a research gap and provides an overview of the theoretical problems we face, and what possible approaches we may use to solve these problems. Specifically, this paper focuses on the problems on both the deployment of the devices (which is the system design/configuration part) and the sensing management of the devices (which is the system running part). We also discuss how to choose the existing algorithms in different type of monitoring applications in smart cities, such as structural health monitoring, water pipeline networks, traffic monitoring. We finally discuss future research opportunities and open challenges for smart city monitoring.

  • 27.
    Du, Rong
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Nätverk och systemteknik.
    Xiao, Ming
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Teknisk informationsvetenskap.
    Fischione, Carlo
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Nätverk och systemteknik.
    Optimal Node Deployment and Energy Provision for Wirelessly Powered Sensor Networks2018Ingår i: IEEE Journal on Selected Areas in Communications, ISSN 0733-8716, E-ISSN 1558-0008, Vol. 37, nr 2, s. 407-423Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In a typical wirelessly powered sensor network (WPSN), wireless chargers provide energy to sensor nodes by using wireless energy transfer (WET). The chargers can greatly improve the lifetime of a WPSN using energy beamforming by a proper charging scheduling of energy beams. However, the supplied energy still may not meet the demand of the energy of the sensor nodes. This issue can be alleviated by deploying redundant sensor nodes, which not only increase the total harvested energy, but also decrease the energy consumption per node provided that an efficient  scheduling of the sleep/awake of the nodes is performed. Such a problem of joint optimal sensor deployment, WET scheduling, and node activation is posed and investigated in this paper. The problem is an integer optimization that is challenging due to the binary decision variables and non-linear constraints. Based on the analysis of the necessary condition such that the WPSN be immortal, we decouple the original problem into a node deployment problem and a charging and activation scheduling problem. Then, we propose an algorithm and prove that it achieves the optimal solution under a mild condition. The simulation results show that the proposed algorithm reduces the needed nodes to deploy by approximately 16%, compared to a random-based approach. The simulation also shows if the battery buffers are large enough, the optimality condition will be easy to meet.

  • 28.
    Fang, Shu
    et al.
    Univ Elect Sci & Technol China, Natl Key Lab Sci & Technol Commun, Chengdu 611731, Sichuan, Peoples R China..
    Zheng, Kaili
    Univ Elect Sci & Technol China, Natl Key Lab Sci & Technol Commun, Chengdu 611731, Sichuan, Peoples R China..
    Xiao, Yue
    Univ Elect Sci & Technol China, Natl Key Lab Sci & Technol Commun, Chengdu 611731, Sichuan, Peoples R China..
    Yang, Yuming
    Univ Elect Sci & Technol China, Natl Key Lab Sci & Technol Commun, Chengdu 611731, Sichuan, Peoples R China..
    Zeng, Xiaojuan
    Univ Elect Sci & Technol China, Natl Key Lab Sci & Technol Commun, Chengdu 611731, Sichuan, Peoples R China..
    Xiao, Ming
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Teknisk informationsvetenskap.
    Offset Spatial Modulation and Offset Space Shift Keying: Efficient Designs for Single-RF MIMO Systems2019Ingår i: IEEE Transactions on Communications, ISSN 0090-6778, E-ISSN 1558-0857, Vol. 67, nr 8, s. 5434-5444Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Spatial modulation (SM) and space shift keying (SSK) techniques have the unique advantages of their single-radio-frequency (RF) structures compared with conventional multiple-input-multiple-output (MIMO) techniques. However, the transmission rates of these techniques are decided by the maximal switching frequency or by the minimal switching time between the RF chain and transmit antennas, which has been a bottleneck for their applications in future broadband wireless communications. To alleviate this problem, we propose a class of novel offset SM (OSM) and offset SSK (OSSK) schemes, with the aid of channel state information (CSI) at the transmitter. Compared with conventional SM and SSK, the proposed OSM and OSSK schemes can reduce the switching frequency of the RF chain, by introducing an offset between the connected RF chain and the index of the spatial modulated antenna. In extreme conditions, the proposed OSM and OSSK can work without RF switching while maintaining the single-RF advantage of conventional SM and SSK schemes. Through theoretical analysis, we also develop the bit-error rate (BER) performance bounds for the proposed two schemes. Finally, our simulation results demonstrate that the proposed OSM and OSSK outperform their counterparts, including conventional SM, SSK, CSI-aided SM, and CSI-aided SSK, while having a simplified RF-switching structure.

  • 29.
    Fang, Zequn
    et al.
    Southwest Jiaotong Univ, Prov Key Lab Informat Coding & Transmiss, Chengdu 610031, Sichuan, Peoples R China..
    Ma, Zheng
    Southwest Jiaotong Univ, Prov Key Lab Informat Coding & Transmiss, Chengdu 610031, Sichuan, Peoples R China..
    Karagiannidis, George K.
    Aristotle Univ Thessaloniki, Elect & Comp Engn Dept, Thessaloniki, Greece..
    Xiao, Ming
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Teknisk informationsvetenskap.
    Fan, Pingzhi
    Southwest Jiaotong Univ, Prov Key Lab Informat Coding & Transmiss, Chengdu 610031, Sichuan, Peoples R China..
    Low complexity decoding of Reed-Solomon codes over magnetic recording channels2019Ingår i: Electronics Letters, ISSN 0013-5194, E-ISSN 1350-911X, Vol. 55, nr 3, s. 159-160Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A low complexity soft-decision decoding technique is presented for Reed-Solomon codes, over magnetic recording channels (MRC), by considering symbol and bit reliability, jointly. A symbol detection scheme for burst error scenarios has been put forward for the iterative error-and-erasure decoding algorithm (IEED), which is based on multiple trials, and is a combination of the generalised minimum distance and Chase-2 decoding schemes. In order to decrease complexity, the decoding test patterns are used in a certain order, while the stopping criteria is also discussed. Simulations show that the proposed algorithms can achieve almost the same performance as that of IEED for the additive white Gaussian noise channel and slightly better performance in MRC, but with significantly less complexity.

  • 30. Fei, Zesong
    et al.
    Cao, Congzhe
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Hussain, Iqbal
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Kuang, Jingming
    Improved Luby transform codes in low overhead regions for binary erasure channels2014Ingår i: Transaction on Emerging Telecommunications Technologies, ISSN 2161-3915Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We study improved degree distribution for Luby transform (LT) codes, which exhibits improved bit error rates particularly in low overhead regions. We construct the degree distribution by modifying robust soliton distribution. The performance of our proposed LT codes is evaluated and compared with the conventional LT codes via And-Or tree analysis. Then we propose a transmission scheme based on our proposed degree distribution to improve the frame error rate in full recovery regions. Furthermore, the improved degree distribution is applied to distributed multi-source relay networks and unequal error protection. It is shown that our schemes achieve better performance and reduced complexity especially in low overhead regions, compared with conventional schemes.

  • 31. Fei, Zesong
    et al.
    Yuan, Jinhong
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Bai, Baoming
    Zhang, Shengli
    Lin, Dengsheng
    RECENT DEVELOPMENT OF ERROR CONTROL CODES FOR FUTURE COMMUNICATION AND STORAGE SYSTEMS2017Ingår i: China Communications, ISSN 1673-5447, Vol. 14, nr 8, s. III-VArtikel i tidskrift (Övrigt vetenskapligt)
  • 32.
    Gao, Yulan
    et al.
    Univ Elect Sci & Technol China, Natl Key Lab Sci & Technol Commun, Chengdu 611731, Sichuan, Peoples R China..
    Xiao, Yue
    Univ Elect Sci & Technol China, Natl Key Lab Sci & Technol Commun, Chengdu 611731, Sichuan, Peoples R China.;Southeast Univ, Natl Mobile Commun Res Lab, Nanjing 210096, Jiangsu, Peoples R China..
    Wu, Mingming
    Univ Elect Sci & Technol China, Natl Key Lab Sci & Technol Commun, Chengdu 611731, Sichuan, Peoples R China..
    Xiao, Ming
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Teknisk informationsvetenskap.
    Energy Efficient Power Allocation With Demand Side Coordination for OFDMA Downlink Transmissions2019Ingår i: IEEE Transactions on Wireless Communications, ISSN 1536-1276, E-ISSN 1558-2248, Vol. 18, nr 4, s. 2141-2155Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We investigate the energy-efficient power allocation for downlink transmission in orthogonal frequency division multiple access-based long term evolution systems. Aiming at realizing on-demand power allocation in cellular networks, we explore the available coordination between the base station and multiple users, and propose a new performance merit, namely, the demand side coordination energy efficiency (DSC-EE), which captures the system normalized EE and the demand side information. The proposed DSC-EE is designed to exploit individual disparities from both the entire system and the individual own expected utility perspectives. Our goal is to maximize the DSC-EE of the system via power allocation with a constraint on the maximum transmit power. Specifically, the objective function of DSC-EE maximization problem in a fractional form can be transformed into a subtractive form that is more tractable based on the fractional programming theory. The convergence property of the proposed algorithms and the meaningfulness of the proposed performance merit related to the EE are demonstrated by simulations. The comparison of four EE metrics, the EE and the rate fairness, global-EE, Sum-EE, and DSC-EE, shows that the DSC-EE maximization tends to achieve high implementation level of on-demand power allocation while ensuring the EE of the system. In addition, when the minimum rate replaces the expected rate in the DSC-EE, further performance comparison indicates the necessity and impact of the expected rate in the tolerable quality of service bias function.

  • 33.
    Gao, Yulan
    et al.
    Univ Elect Sci & Technol China, Natl Key Lab Sci & Technol Commun, Chengdu 611731, Sichuan, Peoples R China..
    Xiao, Yue
    Univ Elect Sci & Technol China, Natl Key Lab Sci & Technol Commun, Chengdu 611731, Sichuan, Peoples R China..
    Wu, Mingming
    Univ Elect Sci & Technol China, Natl Key Lab Sci & Technol Commun, Chengdu 611731, Sichuan, Peoples R China..
    Xiao, Ming
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Teknisk informationsvetenskap.
    Shao, Jinliang
    Univ Elect Sci & Technol China, Sch Math Sci, Chengdu 611731, Sichuan, Peoples R China..
    Game Theory-Based Anti-Jamming Strategies for Frequency Hopping Wireless Communications2018Ingår i: IEEE Transactions on Wireless Communications, ISSN 1536-1276, E-ISSN 1558-2248, Vol. 17, nr 8, s. 5314-5326Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In frequency hopping (FH) wireless communications, finding an effective transmission strategy to properly mitigate jamming has been recently considered as a critical issue, due to the inherent broadcast nature of wireless communications. Recently, game theory has been proposed as a powerful tool for dealing with the jamming problem, which can be considered as a player (jammer) playing against a user (transmitter). Different from existing results, in this paper, a bimatrix game framework is developed for modeling the interaction process between the transmitter and the jammer, and the sufficient and necessary conditions for Nash equilibrium (NE) strategy of the game are obtained under the linear constraints. Furthermore, the relationship between the NE solution and the global optimal solution of the corresponding quadratic programming is presented. In addition, a special analysis case is developed based on the continuous game framework in which each player has a continuum of strategies. Finally, we show that the performance can be improved based on our game theoretic framework, which is verified by numerical investigations.

  • 34.
    Gerami, Majid
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Exact optimized-cost repair in multi-hop distributed storage networks2014Ingår i: 2014 IEEE International Conference on Communications, ICC, IEEE Computer Society, 2014, s. 4120-4124Konferensbidrag (Refereegranskat)
    Abstract [en]

    The problem of exact repair of a failed node in multi-hop networked distributed storage systems is considered. Contrary to the most of the current studies which model the repair process by the direct links from surviving nodes to the new node, the repair is modeled by considering the multi-hop network structure, and taking into account that there might not exist direct links from all the surviving nodes to the new node. In the repair problem of these systems, surviving nodes may cooperate to transmit the repair traffic to the new node. In this setting, we define the total number of packets transmitted between nodes as repair-cost. A lower bound of the repair-cost can thus be found by cut-set bound analysis. In this paper, we show that the lower bound of the repair-cost is achievable for the exact repair of MDS codes in tandem and grid networks, thus resulting in the minimum-cost exact MDS codes. Further, two suboptimal (achievable) bounds for the large scale grid networks are proposed.

  • 35.
    Gerami, Majid
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Repair for distributed storage systems with erasure channels2013Ingår i: Communications (ICC), 2013 IEEE International Conference on, IEEE conference proceedings, 2013, s. 4058-4062Konferensbidrag (Refereegranskat)
    Abstract [en]

    We study the repair problem of distributed storage systems in erasure networks where the packets transmitted from surviving nodes to the new node might be lost. The fundamental storage-bandwidth tradeoff is calculated by multicasting analysis in erasure networks. The optimal tradeoff bound can be asymptotically achieved when the number of transmission (packets) goes to infinity. For a limited number of transmission, we study the probability of successful regenerating. Then, we investigate two approaches of increasing the probability of successful regenerating, namely, by connecting more surviving nodes or by increasing the storage space of nodes. Using more nodes may pose larger delay and in certain situation it might not be possible to connect to more nodes too. We show that in addition to reducing repair bandwidth, increasing storage space can also increase reliability for repair.

  • 36.
    Gerami, Majid
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Fischione, Carlo
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Skoglund, Mikael
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Decentralized minimum-cost repair for distributed storage systems2013Ingår i: Communications (ICC), 2013 IEEE International Conference on, IEEE conference proceedings, 2013, s. 1910-1914Konferensbidrag (Refereegranskat)
    Abstract [en]

    There have been emerging lots of applications for distributed storage systems e.g., those in wireless sensor networks or cloud storage. Since storage nodes in wireless sensor networks have limited battery, it is valuable to find a repair scheme with optimal transmission costs (e.g., energy). The optimal-cost repair has been recently investigated in a centralized way. However a centralized control mechanism may not be available or is very expensive. For the scenarios, it is interesting to study optimal-cost repair in a decentralized setup. We formulate the optimal-cost repair as convex optimization problems for the network with convex transmission costs. Then we use primal and dual decomposition approaches to decouple the problem into subproblems to be solved locally. Thus, each surviving node, collaborating with other nodes, can minimize its transmission cost such that the global cost is minimized. We further study the optimality and convergence of the algorithms. Finally, we discuss the code construction and determine the field size for finding feasible network codes in our approaches.

  • 37.
    Gerami, Majid
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Li, Jun
    KTH, Skolan för elektro- och systemteknik (EES).
    Fischione, Carlo
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik.
    Lin, Z.
    Repair for distributed storage systems with packet erasure channels and dedicated nodes for repair2016Ingår i: IEEE Transactions on Communications, ISSN 0090-6778, E-ISSN 1558-0857, Vol. 64, nr 4, s. 1367-1383, artikel-id 7422022Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We study the repair problem in distributed storage systems where storage nodes are connected through packet erasure channels and some nodes are dedicated to repair [termed as dedicated-for-repair (DR) storage nodes]. We first investigate the minimum required repair-bandwidth in an asymptotic setup, in which the stored file is assumed to have an infinite size. The result shows that the asymptotic repair-bandwidth over packet erasure channels with a fixed erasure probability has a closed-form relation to the repair-bandwidth in lossless networks. Next, we show the benefits of DR storage nodes in reducing the repair bandwidth, and then we derive the necessary minimal storage space of DR storage nodes. Finally, we study the repair in a nonasymptotic setup, where the stored file size is finite. We study the minimum practical-repair-bandwidth, i.e., the repair-bandwidth for achieving a given probability of successful repair. A combinatorial optimization problem is formulated to provide the optimal practical-repair-bandwidth for a given packet erasure probability. We show the gain of our proposed approaches in reducing the repair-bandwidth.

  • 38.
    Gerami, Majid
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Salimi, Somayeh
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsnät.
    Skoglund, Mikael
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Secure Partial Repair in Wireless Caching Networks with Broadcast Channels2015Ingår i: 2015 IEEE Conference on Communications and NetworkSecurity, CNS 2015, 2015, s. 353-360, artikel-id 7346846Konferensbidrag (Refereegranskat)
    Abstract [en]

    We study security in partial repair in wireless caching networks where parts of the stored packets in the caching nodes are susceptible to be erased. Let us denote a caching node that has lost parts of its stored packets as a sick caching node and a caching node that has not lost any packet as a healthy caching node. In partial repair, a set of caching nodes ( among sick and healthy caching nodes) broadcast information to other sick caching nodes to recover the erased packets. The broadcast information from a caching node is assumed to be received without any error by all other caching nodes. All the sick caching nodes then are able to recover their erased packets, while using the broadcast information and the non-erased packets in their storage as side information. In this setting, if an eavesdropper overhears the broadcast channels, it might obtain some information about the stored file. We thus study secure partial repair in the senses of information-theoretically strong and weak security. In both senses, we investigate the secrecy caching capacity, namely, the maximum amount of information which can be stored in the caching network such that there is no leakage of information during a partial repair process. We then deduce the strong and weak secrecy caching capacities, and also derive the sufficient finite field sizes for achieving the capacities. Finally, we propose optimal secure codes for exact partial repair, in which the recovered packets are exactly the same as erased packets.

  • 39.
    Gerami, Majid
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Skoglund, Mikael
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Optimal-cost repair in multi-hop distributed storage systems2011Ingår i: IEEE International Symposium on Information Theory - Proceedings, IEEE , 2011, s. 1437-1441Konferensbidrag (Refereegranskat)
    Abstract [en]

    In distributed storage systems reliability is achieved through redundant storage nodes distributed in the network. Then a data collector can recover source information even if some nodes fail. To maintain reliability, an autonomous and efficient protocol should be used to reconstruct the failed node. Therepairprocess causes traffic in the network. Recent results in e.g., [1], [2] found the optimal traffic-storage tradeoff, and proposed regenerating codes to achieve the optimality. We investigate the link costs and the impact of network topologies during therepairprocess. We formulate the minimum costrepairproblem in joint and decoupled methods. We investigate the required field size for the joint method. For the decoupled method, we show that the optimization problem is linear for the linear cost. We further show that the cooperation of surviving nodes could efficiently exploit the network topology and reduce therepaircost. The numerical results in tandem, star and grid networks show the benefits of our methods in term of the repair cost.

  • 40.
    Gerami, Majid
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Skoglund, Mikael
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Partial Repair for Wireless Caching Networks With Broadcast Channels2015Ingår i: IEEE Wireless Communications Letters, ISSN 2162-2337, E-ISSN 2162-2345, Vol. 4, nr 2, s. 145-148, artikel-id 6987261Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We investigate the repair problem for wireless caching networks when parts of stored packets in cashing nodes are lost. We first develop theoretical lower bounds on the number of necessary transmission packets over error-free broadcast channels for repair. Then we discuss the impact of the distribution of the lost packets among caching nodes. Finally, we study the construction of repair codes and propose the optimal exact repair for some special scenarios.

  • 41.
    Gerami, Majid
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Teknisk informationsvetenskap.
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Teknisk informationsvetenskap.
    Skoglund, Mikael
    KTH, Skolan för elektro- och systemteknik (EES), Teknisk informationsvetenskap.
    Two-Layer Coding in Distributed Storage Systems With Partial Node Failure/Repair2017Ingår i: IEEE Communications Letters, ISSN 1089-7798, E-ISSN 1558-2558, Vol. 21, nr 4, s. 726-729Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We a distributed storage system where parts of the stored packets in storage nodes are subject to being lost. In a process, termed as the partial repair, the lost packets in a faulty node are recovered by the transmitted packets from other storage nodes and the available packets in the faulty node. To improve reliability of the stored data, and reduce the transmission costs, we propose a scheme that implements two-layer coding for storing files in the system. We study the minimum possible partial-repair bandwidth, and the codes that achieve the optimal bound.

  • 42.
    Gerami, Majid
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Skoglund, Mikael
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Shum, K. W.
    Lin, D.
    Optimal-cost repair in multi-hop distributed storage systems with network coding2016Ingår i: Transactions on Emerging Telecommunications Technologies, ISSN 2161-5748, Vol. 27, nr 11, s. 1539-1549Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We study the transmission cost of repair in a distributed storage system, where storage nodes are connected together through an arbitrary network topology, and there is a cost in the use of the network link. Contrary to the classical model, where there exists a link between a pair of storage node, in our repair model there might not exist a link between some pairs of storage nodes or it might be expensive to use. For that, we propose surviving nodes cooperation in repair, meaning that the surviving nodes as the intermediate nodes combine their received packets with their own stored packets and then transmit coded packets towards the new node. We show that surviving node cooperation can reduce the repair-cost, the sum of the costs for transmitting repairing data between the surviving nodes and the new node. For the system that allows surviving node cooperation, we find the minimum-cost codes in repair by firstly deriving a lower bound of the repair-cost through an optimization problem and then proposing achievable codes. We show the gain of the proposed codes in reducing the repair-cost in some scenarios.

  • 43.
    Girnyk, Maksym
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Kildehöj Rasmussen, Lars
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Cooperative communication in multi-source line networks2012Ingår i: 2012 IEEE Wireless Communications and Networking Conference, WCNC, IEEE Communications Society, 2012, s. 2379-2383Konferensbidrag (Refereegranskat)
    Abstract [en]

    Cooperative communication is shown to be an efficient method of combating fading in wireless networks. By "sharing" their antennas cooperating single-antenna nodes create a virtual multi-antenna system and therefore, benefit from spatial diversity. Network coding being a particular cooperative communication technique provides substantial gains in data rate, especially in networks with many sink nodes. By allowing intermediate nodes of a network to mix the incoming data streams, one can achieve the multicast capacity. Recently, Xiao and Skoglund showed that binary network coding (BNC) is not optimal for multi-user multi-relay networks in terms of diversity and proposed diversity network coding (DNC) scheme that outperforms BNC approach. Following this approach we examine potential diversity gains of using the DNC scheme for multi-source line networks. We show that the DNC technique outperforms both conventional time-orthogonal transmission and the BNC scheme. Further, the problem of optimal scheduling of the transmission is explored. We formulate the optimization problem and propose efficient solutions. Numerical results are presented to support theoretical findings.

  • 44.
    Girnyk, Maksym
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Rasmussen, Lars
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Power Allocation for Multi-Hop Decode-and-Forward Cognitive Radio Networks with Line Topology2012Ingår i: 2012 Swedish Communication Technologies Workshop, Swe-CTW 2012, Lund, 2012, s. 7-12Konferensbidrag (Refereegranskat)
    Abstract [en]

    In the present paper we study the power allocation for multi-hop underlay cognitive radio networks (CRNs) with line topology. That is, we consider a scenario, where a CRN operates in parallel to the primary network provided that the interference created to the primary network is limited by an acceptable threshold. The CNR is assumed to be a multi-hop relay network and hence before reaching the destination information from the source node may pass several hops from node to node. At each hop, the information is decoded and forwarded to the following node. It is further assumed that transmissions can be overheard by neighboring nodes, thereby creating interference. The power at each node can be optimally adjusted so that the end-to-end throughput of the CRN is maximized, while the constraint on interference towards the primary network is satisfied. In this paper, we show that for line CRNs the optimal power allocation is achieved when capacities of all intermediate links are equal and the interference constraint of the most disturbed primary user is fulfilled with equality. To simplify the computation of the optimal power allocation we derive two approximate solutions as well as several distributed power allocation schemes. The numerical results illustrate the interplay between the proposed solutions and the optimal power allocation.

  • 45.
    Girnyk, Maksym
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Rasmussen, Lars Kildehöj
    KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Optimal Power Allocation in Multi-Hop Cognitive Radio Networks2011Ingår i: 2011 IEEE 22nd International Symposium On Personal Indoor And Mobile Radio Communications (PIMRC), New York: IEEE conference proceedings, 2011, s. 472-476Konferensbidrag (Refereegranskat)
    Abstract [en]

    Optimal power allocation in a multi-hop cognitive radio network is investigated. Information transmitted from the source passes through several wireless relay nodes before reaching the destination. At each hop, the received signal is decoded, re-encoded and retransmitted to the following node. Transmissions at every hop are overheard by nearby nodes and therefore cause interference. We study optimal power allocation strategies that maximize the end-to-end throughput of the network under the constraint of strictly limited interference to external users. We show that for networks that can be modeled as a line topology the optimal solution is achieved when the capacities of every intermediate link are equal and the interference power constraint is satisfied with equality. High-and low-SNR approximations that simplify the problem of finding the optimal power allocation are presented as well. The numerical results show good performance compared to schemes with equal power allocation.

  • 46.
    He, Shiwen
    et al.
    Southeast Univ, State Key Lab Millimeter Waves, Nanjing 210096, Jiangsu, Peoples R China.;Cent S Univ, Sch Informat Sci & Engn, Changsha 410083, Hunan, Peoples R China..
    Huang, Yongming
    Southeast Univ, Natl Mobile Commun Res Lab, Nanjing 210096, Jiangsu, Peoples R China..
    Xiao, Ming
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Teknisk informationsvetenskap.
    Wang, Jiaheng
    Cent S Univ, Sch Informat Sci & Engn, Changsha 410083, Hunan, Peoples R China..
    Energy Efficient Hybrid Precoding for Millimeter Wave F-RAN with Wireless Fronthaul2018Ingår i: 2018 IEEE Global Communications Conference, GLOBECOM 2018 - Proceedings, IEEE, 2018, artikel-id 8647930Konferensbidrag (Refereegranskat)
    Abstract [en]

    Millimeter wave (mmWave) communication emerges as an enabling technology for Gbps transmission. A further performance enhancement can be achieved by incorporating mmWave communication into fog radio access networks (F-RANs), which alleviate the large path loss of mmWave signals by shortening the distance between transmitters and users and reduce the latency by caching at enhanced remote radio heads (eRRHs). The full benefit of mmWave F-RANs is leveraged on a joint design of signal processing at the centralized baseband unit (BBU) and distributed eRRHs. In this paper, we propose an energy efficient hybrid precoding design for the downlink mmWave F-RANs with wireless fronthaul links, where digital and hybrid precoders are exploited at the BBU and eRRHs, respectively. We develop an effective method to solve the resulting difficult precoding optimization problem and provide numerical results to demonstrate the effectiveness of the proposed mmWave F-RAN design.

  • 47.
    Huang, Jin
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Teknisk informationsvetenskap.
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES), Teknisk informationsvetenskap.
    State of the art on road traffic sensing and learning based on mobile user network log data2018Ingår i: Neurocomputing, ISSN 0925-2312, E-ISSN 1872-8286, Vol. 278, s. 110-118Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    With the improvement of the storage and big data processing technology, mobile operators are able to extract and store a large amount of mobile network generated user behavior data, in order to develop various intelligent applications. One interesting application based on these data is traffic sensing, which uses techniques of learning human mobility patterns from updated location information in network interaction log data. Mobile networks, under which a huge amount of frequently updated location information of mobile users are tracked, can provide complete coverage to estimate traffic condition on roads and highways. This paper studies potential challenges and opportunities in intelligent traffic sensing from the data science point of view with mobile network generated data. Firstly, we classify the data resources available in the commercial radio network according to different taxonomy criteria. Then we outline the broken-down problems that fit in the framework of traffic sensing based on mobile user network log data. We study the existing data processing and learning algorithms on extracting traffic condition information from a large amount of mobile network log data. Finally we make suggestion on potential future work for traffic sensing on data from mobile networks. We believe the techniques and insights provided here will inspire the research community in data science to develop the machine learning models of traffic sensing on the widely collected mobile user behavior data.

  • 48.
    Huang, Jingxuan
    et al.
    Beijing Inst Technol, Sch Informat & Elect, Beijing 100081, Peoples R China..
    Fei, Zesong
    Beijing Inst Technol, Sch Informat & Elect, Beijing 100081, Peoples R China..
    Cao, Congzhe
    Univ Alberta, Dept Elect & Comp Engn, Edmonton, AB T6G 1H9, Canada..
    Xiao, Ming
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Teknisk informationsvetenskap.
    Jia, Dai
    Beijing Inst Technol, Sch Informat & Elect, Beijing 100081, Peoples R China..
    Performance Analysis and Improvement of Online Fountain Codes2018Ingår i: IEEE Transactions on Communications, ISSN 0090-6778, E-ISSN 1558-0857, Vol. 66, nr 12, s. 5916-5926Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The online property of fountain codes enables the encoder to efficiently find the optimal encoding strategy that minimizes the encoding overhead based on the instantaneous decoding state. Therefore, the receiver is able to optimally recover data from losses that differ significantly from the initial expectation. In this paper, we propose a framework to analyze the relationship between overhead and the number of recovered source symbols for online fountain codes based on random graph theory. Motivated by the analysis, we propose improved online fountain codes (IOFCs) by introducing a designated selection of source symbols. Theoretical analysis shows that IOFC has lower overhead compared with the conventional online fountain codes. We verify the proposed analysis via simulation results and demonstrate the tradeoff between full recovery and intermediate performance in comparison to other online fountain codes.

  • 49.
    Huang, Shaocheng
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Teknisk informationsvetenskap.
    Xiao, Ming
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Teknisk informationsvetenskap.
    Achievable Rate Analysis of Millimeter Wave Channels with Random Coding Error Exponent2019Ingår i: IEEE International Conference on Communications, Institute of Electrical and Electronics Engineers (IEEE), 2019, Vol. 2019, artikel-id 8761470Konferensbidrag (Refereegranskat)
    Abstract [en]

    Millimeter Wave (mmWave) communication has attracted massive attentions, since the abundant available bandwidth can potentially provide reliable communication with orders of magnitude capacity improvements relative to microwave. However, the achievable rate of mmWave channels under latency and reliability constraints is still not quite clear. We investigate the achievable rates of mmWave channels by random coding error exponent (RCEE) with finite blocklength. With imperfect channel state information at the receiver, the exact and approximate analytical expressions of the training based maximum achievable rate are derived to capture the relationship among rate-latency-reliability. Additionally, the relationship between the training based maximum achievable rate and bandwidth is investigated. We show that there exists critical bandwidth to maximize the training based maximum achievable rate for the non-line-of-sight (NLoS) propagation. Numerical results show that the approximate expression of the training based maximum achievable rate are tight and can capture the tendency at low SNRs. In addition, results show that for a given rate, one can reduce both packet duration and decoding error probability by increasing bandwidth. Results also suggest that in some mmWave bands, e.g. 57-64 GHz band, the performance, i.e., Gallager function, is significantly affected by frequency selective power absorption.

  • 50.
    Huang, Yongming
    et al.
    Southeast Univ, Sch Informat Sci & Engn, Natl Mobile Commun Res Lab, Nanjing 210096, Jiangsu, Peoples R China..
    Zhang, Jianjun
    Southeast Univ, Sch Informat Sci & Engn, Natl Mobile Commun Res Lab, Nanjing 210096, Jiangsu, Peoples R China..
    Xiao, Ming
    KTH, Skolan för elektro- och systemteknik (EES).
    Constant Envelope Hybrid Precoding for Directional Millimeter-Wave Communications2018Ingår i: IEEE Journal on Selected Areas in Communications, ISSN 0733-8716, E-ISSN 1558-0008, Vol. 36, nr 4, s. 845-859Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Millimeter wave (mmwave) communication has attracted increasing attention owing to its abundant spectrum resource. The short wavelength at mmwave frequencies facilitates placing a large number of antennas in a small space, and the mmwave channels are likely to be sparse in the directions. These two new features promise enhanced security by directional precoding. To explore this potential, we investigate the design of directional hybrid digital and analog precoding for the multiuser mmwave communication system with multiple eavesdroppers. Particularly, we consider two cost-efficient sub-connected hybrid architectures, i.e., multi-subarray architecture and switched phased- array architecture, and optimize the hybrid precoding under per-antenna constant envelope (CE) constraints. The goal of our design is to guarantee the receive quality of the legitimate users while minimizing the power leaked to the eavesdroppers, so as to realize a directional transmission for a general mmwave channel. The resulting problems are very challenging due to the nonlinear CE constraints and binary integer constraint from antenna selection. To address them, we leverage exact penalty function methods to find efficient solutions to the CE hybrid directional precoding. Our analysis shows that the proposed algorithm is able to converge to a stationary point under some mild conditions. Simulation results are finally provided to confirm the effectiveness of the proposed schemes and their superiority over the existing schemes under both single-path and multi-path mmwave channels.

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