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Rasmussen, Lars KildehöjORCID iD iconorcid.org/0000-0001-7182-9543
Alternative names
Publications (10 of 187) Show all publications
Zaki, A., Chatterjee, S. & Rasmussen, L. K. (2017). Generalized fusion algorithm for compressive sampling reconstruction and RIP-based analysis. Signal Processing, 139, 36-48.
Open this publication in new window or tab >>Generalized fusion algorithm for compressive sampling reconstruction and RIP-based analysis
2017 (English)In: Signal Processing, ISSN 0165-1684, E-ISSN 1872-7557, Vol. 139, 36-48 p.Article in journal (Refereed) Published
Abstract [en]

We design a Generalized Fusion Algorithm for Compressive Sampling (gFACS) reconstruction. In the gFACS algorithm, several individual compressive sampling (CS) reconstruction algorithms participate to achieve a better performance than the individual algorithms. The gFACS algorithm is iterative in nature and its convergence is proved under certain conditions using Restricted Isometry Property (RIP) based theoretical analysis. The theoretical analysis allows for the participation of any off-the-shelf or new CS reconstruction algorithm with simple modifications, and still guarantees convergence. We show modifications of some well-known CS reconstruction algorithms for their seamless use in the gFACS algorithm. Simulation results show that the proposed gFACS algorithm indeed provides better performance than the participating individual algorithms.

Place, publisher, year, edition, pages
ELSEVIER SCIENCE BV, 2017
Keyword
Compressive sampling, Greedy algorithm, RIP analysis, Fusion strategy
National Category
Signal Processing
Identifiers
urn:nbn:se:kth:diva-208710 (URN)10.1016/j.sigpro.2017.03.021 (DOI)000402214200004 ()2-s2.0-85017439915 (Scopus ID)
Note

QC 2017-06-12

Available from: 2017-06-12 Created: 2017-06-12 Last updated: 2017-06-15Bibliographically approved
Larsson, P., Gross, J., Al-Zubaidy, H., Rasmussen, L. K. & Skoglund, M. (2016). Effective Capacity of Retransmission Schemes: A Recurrence Relation Approach. IEEE Transactions on Communications, 64(11), 4817-4835.
Open this publication in new window or tab >>Effective Capacity of Retransmission Schemes: A Recurrence Relation Approach
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2016 (English)In: IEEE Transactions on Communications, ISSN 0090-6778, E-ISSN 1558-0857, Vol. 64, no 11, 4817-4835 p.Article in journal (Refereed) Published
Abstract [en]

We consider the effective capacity performance measure of persistent-and truncated-retransmission schemes that can involve any combination of multiple transmissions per packet, multiple communication modes, or multiple packet communication. We present a structured unified analytical approach, based on a random walk model and recurrence relation formulation, and give exact effective capacity expressions for persistent hybrid automatic repeat request (HARQ) and for truncated-retransmission schemes. For the latter, effective capacity expressions are given for systems with finite (infinite) time horizon on an algebraic (spectral radius-based) form of a special block companion matrix. In contrast to prior HARQ models, assuming infinite time horizon, the proposed method does not involve a non-trivial per case modeling step. We give effective capacity expressions for several important cases that have not been addressed before, e.g., persistent-HARQ, truncated-HARQ, network-coded ARQ, two-mode-ARQ, and multilayer-ARQ. We propose an alternative quality-of-service-parameter (instead of the commonly used moment generating function parameter) that represents explicitly the target delay and the delay violation probability. This also enables the closed-form expressions for many of the studied systems. Moreover, we use the recently proposed matrix-exponential distributed modeling of wireless fading channels to provide the basis for numerous new effective capacity results for HARQ.

Place, publisher, year, edition, pages
IEEE, 2016
Keyword
Recurrence relation, retransmission, automatic repeat request, hybrid-ARQ, repetition redundancy, network coding, multilayer-ARQ, effective capacity, throughput, matrix exponential distribution, random walk
National Category
Telecommunications
Identifiers
urn:nbn:se:kth:diva-199563 (URN)10.1109/TCOMM.2016.2602864 (DOI)000388873800028 ()2-s2.0-84999748064 (Scopus ID)
Note

QC 20170113

Available from: 2017-01-13 Created: 2017-01-09 Last updated: 2017-11-29Bibliographically approved
Larsson, P., Rasmussen, L. K. & Skoglund, M. (2016). Throughput Analysis of Hybrid-ARQ -A Matrix Exponential Distribution Approach. IEEE Transactions on Communications, 64(1), 416-428.
Open this publication in new window or tab >>Throughput Analysis of Hybrid-ARQ -A Matrix Exponential Distribution Approach
2016 (English)In: IEEE Transactions on Communications, ISSN 0090-6778, E-ISSN 1558-0857, Vol. 64, no 1, 416-428 p.Article in journal (Refereed) Published
Abstract [en]

We propose a novel performance analysis framework for lossless- and truncated-hybrid automatic repeat request (HARQ) that enables neat, general, closed-form throughput expressions in a matrix exponential (ME) distribution form. This approach is applicable to all HARQ schemes for which the probability density function of the effective channel can be characterized by a rational Laplace transform, or equivalently, an ME-distribution. This includes, for example, repetition redundancy HARQ in ME distributed channels. Throughput expressions are also given for the K-truncated-HARQ N-fold diversity, ARQ N-fold diversity, and lossless-HARQ 2-fold diversity cases in the ME distributed channel. Schemes with effective channels of non-rational Laplace transforms, such as IR-HARQ, are explored using truncated continued fractions. A novel integration trick is developed for the integration of ME distributions with singular matrices and yields the simple throughput expression of lossless-HARQ. We also give general analytical expressions for the optimal throughput and optimal rate point that benefit from the compact ME-distribution form proposed.

Place, publisher, year, edition, pages
IEEE Press, 2016
Keyword
Hybrid-ARQ (HARQ), lossless-HARQ, truncated-HARQ, retransmission, repetition redundancy, chase combining, incremental redundancy, ARQ, throughput, matrix exponential distribution, rational Laplace transform, performance optimization
National Category
Communication Systems
Identifiers
urn:nbn:se:kth:diva-182166 (URN)10.1109/TCOMM.2015.2501294 (DOI)000368353700036 ()2-s2.0-84958149474 (Scopus ID)
Note

QC 20160218

Available from: 2016-02-18 Created: 2016-02-16 Last updated: 2017-11-30Bibliographically approved
Grosjean, L., Thobaben, R., Rasmussen, L. K. & Skoglund, M. (2016). Variable-rate anytime transmission with feedback. In: IEEE Vehicular Technology Conference: . Paper presented at 84th IEEE Vehicular Technology Conference, VTC Fall 2016, 18 September 2016 through 21 September 2016. IEEE, Article ID 7881963.
Open this publication in new window or tab >>Variable-rate anytime transmission with feedback
2016 (English)In: IEEE Vehicular Technology Conference, IEEE, 2016, 7881963Conference paper, Published paper (Refereed)
Abstract [en]

A generalization of the ensemble of non-terminated systematic LDPC convolutional codes developed in our previous work is proposed that allows us to design codes with lower rates than the original structure. We show that over the BEC, the modified codes have improved asymptotic and finite-length behavior and we determine the operational anytime exponent. Having shown the advantages of lowering the rate of the code, we propose a feedback protocol that permits encoder and decoder to operate at a variable rate. The rate is set on-the-fly and depends on the decoding success of the decoder. We describe the construction of the variable rate code structure and demonstrate by simulations the superiority of the variable rate scheme as compared to a scheme using a fixed rate.

Place, publisher, year, edition, pages
IEEE, 2016
Keyword
Convolutional codes, Decoding, Design codes, Feedback protocol, Finite length, LDPC convolutional codes, On the flies, Original structures, Variable rate, Variable rate codes, Codes (symbols)
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-210142 (URN)10.1109/VTCFall.2016.7881963 (DOI)000402610200441 ()2-s2.0-85016981677 (Scopus ID)9781509017010 (ISBN)
Conference
84th IEEE Vehicular Technology Conference, VTC Fall 2016, 18 September 2016 through 21 September 2016
Note

QC 20170630

Available from: 2017-06-30 Created: 2017-06-30 Last updated: 2017-06-30Bibliographically approved
Vehkapera, M., Riihonen, T., Girnyk, M., Björnson, E., Debbah, M., Kildehøj Rasmussen, L. & Wichman, R. (2015). Asymptotic analysis of asymmetric MIMO links: EVM limits for joint decoding of PSK and QAM. In: 2015 IEEE International Conference on Communications (ICC): . Paper presented at IEEE International Conference on Communications, ICC 2015, London, United Kingdom, 8 June 2015 through 12 June 2015 (pp. 1869-1873). IEEE conference proceedings, 2015.
Open this publication in new window or tab >>Asymptotic analysis of asymmetric MIMO links: EVM limits for joint decoding of PSK and QAM
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2015 (English)In: 2015 IEEE International Conference on Communications (ICC), IEEE conference proceedings, 2015, Vol. 2015, 1869-1873 p.Conference paper, Published paper (Refereed)
Abstract [en]

Hardware non-idealities in wireless transmitter electronics cause distortion that is not captured by conventional linear channel models; in fact, error-vector magnitude (EVM) measurements in conformance testing conceptually reduce their collective effect to an additive noise component at each subcarrier. Motivated by the EVM, the present paper considers a 'binoisy' multiple-input multiple-output (MIMO) channel model where the additional non-idealities manifest themselves as an additive distortion noise term at the transmit side. Through this extended MIMO relation, the effects of hardware impairments on the achievable rates of different digital modulation schemes are studied via large system analysis. The numerical results illustrate how tolerable EVM levels depend non-trivially on various factors, including the signal-to-noise ratio, modulation order and the level of asymmetry in antenna array configurations.

Place, publisher, year, edition, pages
IEEE conference proceedings, 2015
Series
IEEE International Conference on Communications, ISSN 1550-3607
Keyword
Statistical Physics, Capacity, Systems, CDMA
National Category
Communication Systems
Identifiers
urn:nbn:se:kth:diva-181157 (URN)10.1109/ICC.2015.7248597 (DOI)000371708102013 ()2-s2.0-84953708408 (Scopus ID)978-1-4673-6432-4 (ISBN)
Conference
IEEE International Conference on Communications, ICC 2015, London, United Kingdom, 8 June 2015 through 12 June 2015
Note

QC 20160216, QC 20160421

Available from: 2016-02-16 Created: 2016-01-29 Last updated: 2016-04-21Bibliographically approved
Vehkapera, M., Riihonen, T., Girnyk, M. A., Bjornson, E., Debbah, M., Kildehøj, L. & Wichman, R. (2015). Asymptotic Analysis of SU-MIMO Channels With Transmitter Noise and Mismatched Joint Decoding. IEEE Transactions on Communications, 63(3), 749-765.
Open this publication in new window or tab >>Asymptotic Analysis of SU-MIMO Channels With Transmitter Noise and Mismatched Joint Decoding
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2015 (English)In: IEEE Transactions on Communications, ISSN 0090-6778, E-ISSN 1558-0857, Vol. 63, no 3, 749-765 p.Article in journal (Refereed) Published
Abstract [en]

Hardware impairments in radio-frequency components of a wireless system cause unavoidable distortions to transmission that are not captured by the conventional linear channel model. In this paper, a "binoisy" single-user multiple-input multiple-output (SU-MIMO) relation is considered where the additional distortions are modeled via an additive noise term at the transmit side. Through this extended SU-MIMO channel model, the effects of transceiver hardware impairments on the achievable rate of multi-antenna point-to-point systems are studied. Channel input distributions encompassing practical discrete modulation schemes, such as, QAM and PSK, as well as Gaussian signaling are covered. In addition, the impact of mismatched detection and decoding when the receiver has insufficient information about the non-idealities is investigated. The numerical results show that for realistic system parameters, the effects of transmit-side noise and mismatched decoding become significant only at high modulation orders.

National Category
Telecommunications
Identifiers
urn:nbn:se:kth:diva-164468 (URN)10.1109/TCOMM.2014.2385051 (DOI)000351507600014 ()2-s2.0-84926326751 (Scopus ID)
Funder
Swedish Research Council
Note

QC 20150422

Available from: 2015-04-22 Created: 2015-04-17 Last updated: 2017-12-04Bibliographically approved
Nguyen, K. D., Timo, R. & Rasmussen, L. K. (2015). Causal-CSIT rate adaptation for block-fading channels. In: IEEE International Symposium on Information Theory - Proceedings: . Paper presented at IEEE International Symposium on Information Theory, ISIT 2015, 14 June 2015 through 19 June 2015 (pp. 351-355). Institute of Electrical and Electronics Engineers (IEEE).
Open this publication in new window or tab >>Causal-CSIT rate adaptation for block-fading channels
2015 (English)In: IEEE International Symposium on Information Theory - Proceedings, Institute of Electrical and Electronics Engineers (IEEE), 2015, 351-355 p.Conference paper, Published paper (Refereed)
Abstract [en]

We propose a rate-adaptive error-correction coding framework for transmission over finite-length block-fading channels, with causal channel state information at the transmitter. A dynamic programming optimization approach can be use to obtain the optimal rate adaptation strategy. A suboptimal rate adaptation strategy is developed for sequential random codes. Numerical results show that significant performance gains are achievable with the proposed adaptation scheme. © 2015 IEEE.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2015
Keyword
Channel state information, Error correction, Fading channels, Information theory, Adaptation scheme, Adaptive error, Block fading channel, Causal channel state informations, Numerical results, Optimization approach, Performance Gain, Rate adaptation, Dynamic programming
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-196171 (URN)10.1109/ISIT.2015.7282475 (DOI)000380904700070 ()2-s2.0-84969902631 (Scopus ID)9781467377041 (ISBN)
Conference
IEEE International Symposium on Information Theory, ISIT 2015, 14 June 2015 through 19 June 2015
Note

Funding Details: DE12010016, ARC, Australian Research Council. QC 20161115

Available from: 2016-11-15 Created: 2016-11-14 Last updated: 2017-02-22Bibliographically approved
Stathakis, E., Rasmussen, L. K. & Skoglund, M. (2015). Closed-Form Capacity Result for Interference-Limited Environments With Mixed Fading. IEEE Transactions on Communications, 63(6), 2374-2387.
Open this publication in new window or tab >>Closed-Form Capacity Result for Interference-Limited Environments With Mixed Fading
2015 (English)In: IEEE Transactions on Communications, ISSN 0090-6778, E-ISSN 1558-0857, Vol. 63, no 6, 2374-2387 p.Article in journal (Refereed) Published
Abstract [en]

We study a multinode network, where a multiantenna transmitter T-x communicates with its desired receiver R-x, whereas a cluster P (sic) {P-x,P- n, n = 1,..., N} of unintended nodes is disturbed by the T-x-R-x (TR) communication. To prevent severe performance degradation, we impose a constraint on the total interference that is inflicted at the nodes of P. The TR link contains a line-of-sight component, whereas the propagation environment for each T-x-P-x, n link is shadowed. The T-x node is preprocessing the information sequence by means of a precoding matrix that is optimized to achieve the ergodic capacity under a constraint on the maximum admissible ergodic interference power, arriving on P. In this paper, we show that the optimum precoding strategy involves the transmission of a single stream over the precoding direction, i.e., the eigenvector of the precoding matrix, which corresponds to beamforming along the instantaneous direction of the TR-link channel. The solution of the remaining power allocation problem yields the optimal precoding matrix. For this setup, we provide an efficient stochastic characterization of the network, which allows us to obtain an analytical expression for the TR-link ergodic capacity; this problem has been previously open, even for the case of a single-antenna node T-x and a single-element set P. We complement the analysis by deriving the TR-link signal-to-noise ratio and the average bit error rate, which are associated with our transmission scheme. Numerical results corroborate the theoretical analysis and reveal an interplay between the network parameters and their impact on the TR-link performance.

Keyword
capacity, F-distribution, interference, line-of-sight, multiple antennas, outage probability, power allocation
National Category
Communication Systems
Identifiers
urn:nbn:se:kth:diva-170689 (URN)10.1109/TCOMM.2015.2427351 (DOI)000356299500035 ()2-s2.0-84933566592 (Scopus ID)
Note

QC 20150707

Available from: 2015-07-07 Created: 2015-07-03 Last updated: 2017-12-04Bibliographically approved
Hussain, I., Xiao, M. & Rasmussen, L. K. (2015). Erasure Floor Analysis of Distributed LT Codes. IEEE Transactions on Communications, 63(8), 2788-2796.
Open this publication in new window or tab >>Erasure Floor Analysis of Distributed LT Codes
2015 (English)In: IEEE Transactions on Communications, ISSN 0090-6778, E-ISSN 1558-0857, Vol. 63, no 8, 2788-2796 p.Article in journal (Refereed) Published
Abstract [en]

We investigate the erasure floor performance of distributed Luby transform (DLT) codes for transmission within a multi-source, single-relay, and single-destination erasure-link network. In general, Luby transform (LT) codes exhibit a high erasure floor due to poor minimum-distance properties, which can be improved by maximizing the minimum variable-node degree. The same behavior is observed for DLT codes, and therefore a new combining scheme at the relay is proposed to maximize the minimum variable-node degree in the decoding graph. Furthermore, the encoding process at the sources and the combining scheme at the relay are coordinated to improve the transmission overhead. To characterize the asymptotic performance of the proposed DLT codes, we derive closed-form density-evolution expressions, considering both lossless and lossy source-relay channels, respectively. To support the asymptotic analysis, we evaluate the performance of the proposed DLT codes by numerical examples and demonstrate that the numerical results correspond closely to the analysis. Significant improvements in both the erasure floor and transmission overhead are obtained for the proposed DLT codes, as compared to conventional DLT codes.

Keyword
Multi-source networks, distributed LT codes, buffer, relay combining, erasure floor
National Category
Telecommunications
Identifiers
urn:nbn:se:kth:diva-173278 (URN)10.1109/TCOMM.2015.2451640 (DOI)000359535700005 ()2-s2.0-84939443909 (Scopus ID)
Note

QC 20150909

Available from: 2015-09-09 Created: 2015-09-09 Last updated: 2017-12-04Bibliographically approved
Girnyk, M., Gabry, F., Vehkaperä, M., Rasmussen, L. K. & Skoglund, M. (2015). MIMO wiretap channels with randomly located eavesdroppers: Large-system analysis. In: 2015 IEEE International Conference on Communication Workshop, ICCW 2015: . Paper presented at IEEE International Conference on Communication Workshop, ICCW 2015, 8 June 2015 through 12 June 2015 (pp. 480-484). IEEE conference proceedings.
Open this publication in new window or tab >>MIMO wiretap channels with randomly located eavesdroppers: Large-system analysis
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2015 (English)In: 2015 IEEE International Conference on Communication Workshop, ICCW 2015, IEEE conference proceedings, 2015, 480-484 p.Conference paper, Published paper (Refereed)
Abstract [en]

Security issues in wireless networks have become a subject of growing interest in recent years due to the broadcast nature of wireless channels. In this paper, we investigate secure communication over a multi-antenna wiretap channel in the presence of randomly distributed eavesdroppers. In the fast fading environment, the overall performance of this channel is traditionally characterized by the ergodic secrecy capacity, which, in general, cannot be derived explicitly. Nevertheless, based on the assumption that the numbers of antennas at legitimate terminals and the number of eavesdroppers grow large without bound, we derive a deterministic approximation of an achievable ergodic secrecy rate for arbitrary inputs. In addition, we characterize the secrecy rates for practically relevant separate-decoding scheme at the receiver. We validate the proposed large-system approximation through numerical simulations and observe a good match with the actual secrecy rates. Finally, we also analyze some interesting behavior of the secrecy rates in the given scenario depending on the geometry of the nodes.

Place, publisher, year, edition, pages
IEEE conference proceedings, 2015
Keyword
Communication channels (information theory), Information dissemination, Arbitrary inputs, Deterministic approximation, Fast fading environments, Large system analysis, Mimo wiretap channels, Randomly distributed, Wire-tap channels, Wireless channel, Antennas
National Category
Telecommunications
Identifiers
urn:nbn:se:kth:diva-181584 (URN)10.1109/ICCW.2015.7247226 (DOI)000380459900081 ()2-s2.0-84947728485 (Scopus ID)9781467363051 (ISBN)
Conference
IEEE International Conference on Communication Workshop, ICCW 2015, 8 June 2015 through 12 June 2015
Note

QC 20160229

Available from: 2016-02-29 Created: 2016-02-02 Last updated: 2016-09-23Bibliographically approved
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Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-7182-9543

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