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  • 1.
    Ansari, Muhammad Adeel
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture (Closed 20120101), Communication Systems, CoS (closed 2012-01-01).
    Ahmad, Waqar
    KTH, School of Information and Communication Technology (ICT), Electronic Systems.
    Signell, Svante R.
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture (Closed 20120101), Communication Systems, CoS (closed 2012-01-01).
    Single clock charge pump designed in 0.35μm technology2011In: Proceedings of the 18th International Conference - Mixed Design of Integrated Circuits and Systems, MIXDES 2011, 2011, p. 552-556Conference paper (Refereed)
    Abstract [en]

    An on-chip novel design of a single clock charge pump for high voltage applications is being presented in this paper. The proposed charge pump is designed using AMS 0.35μm technology. Three stages of the proposed charge pump are being used for the results verification and comparing them with the six stages of Dickson charge pump designed with diode connected PMOS. The proposed charge pump gives an output voltage of 5.34V at no-load. The proposed charge pump gives maximum efficiencies of 89% on 1MHz frequency and 87.4% on 5MHz frequency using 1Mohm load resistance. The efficiency and the output voltage including voltage gain per stage of the proposed charge pump are higher than the Dickson charge pump measured under similar conditions mediating that the performance of proposed charge pump is better than the Dickson charge pump.

  • 2. Badaroglu, M.
    et al.
    Donnay, S.
    De Man, H. J.
    Zinzius, Y. A.
    Gielen, G. G. E.
    Sansen, W.
    Fonden, T.
    Signell, Svante
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Modeling and experimental verification of substrate noise generation in a 220-Kgates WLAN system-on-chip with multiple supplies2003In: IEEE Journal of Solid-State Circuits, ISSN 0018-9200, E-ISSN 1558-173X, Vol. 38, no 7, p. 1250-1260Article in journal (Refereed)
    Abstract [en]

    Substrate noise is a major obstacle for mixed-signal integration. While the power consumption scales linearly with the clock frequency, substrate noise does not have thin scaling due to the resonances in the transfer function of the supply current to the substrate. This paper addresses a practical technique to estimate the substrate noise frequency spectrum of a large mixed-mode System-on-Chip (SoC) with multiple supplies and embedded memories. The results have been verified with substrate noise measurements on a 60-MHz 220-Kgates telecom SoC implemented in a 0.3 mum CMOS process on an EPI-type substrate. We compute a linear chip-level substrate model together with the single-cycle representation of piecewise-linear noise sources of three. supply regions used in this ASIC. Based on this model we accurately estimate the four major resonances in the substrate poise spectrum and their relative magnitudes with 2 dB relative error at the major resonance with respect to measurements. We also present substrate noise measurements at different operating modes of the WLAN receiver. These measurements show that output I/O buffers generate significant substrate noise where an increase of 44% is measured for substrate noise peak-to-peak value due to the additional simultaneous switching of six output I/O buffers with already fully switching datapath and two output I/Os.

  • 3.
    Du, Jinfeng
    et al.
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Signell, Svante
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Classic OFDM Systems and Pulse Shaping OFDM/OQAM Systems2007Report (Other academic)
    Abstract [en]

    In this report, we provide a comparative study of state-of-the-art in Orthogonal Frequency Division Multiplexing (OFDM) techniques with orthonormal analysis and synthesis basis. Two main categories, OFDM/QAM which adopts base-band Quadrature Amplitude Modulation (QAM) and rectangular pulse shape, and OFDM/OQAM which uses baseband offset QAM and various pulse shapes, are intensively reviewed. OFDM/QAM can provide high data rate communication and effectively remove intersymbol interference (ISI) by employing guard interval, which costs a loss of spectral efficiency and increases power consumption. Meanwhile it remains very sensitive to frequency offset which causes inter-carrier interference (ICI). In order to achieve better spectral efficiency and reducing combined ISI/ICI, OFDM/OQAM using well designed pulses with proper Time Frequency Localization (TFL) is of great interest. Various prototype functions, such as rectangular, half cosine, Isotropic Orthogonal Transfer Algorithm (IOTA) function and Extended Gaussian Functions (EGF) are discussed and simulation results are provided to illustrate the TFL properties by the ambiguity function and the interference function.

  • 4.
    Du, Jinfeng
    et al.
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Signell, Svante
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Comparison of CP-OFDM and OFDM/OQAM in doubly dispersive channels2007In: PROCEEDINGS OF FUTURE GENERATION COMMUNICATION AND NETWORKING, WORKSHOP PAPERS, VOL 2, LOS ALAMITOS: IEEE conference proceedings, 2007, p. 207-211Conference paper (Refereed)
    Abstract [en]

    In this paper we compare the performance of cyclic prefix based OFDM (CP-OFDM) system and OFDM/offset QAM (OFDM/OQAM) system in doubly dispersive channels, by investigating the signal reconstruction perfectness, time and frequency dispersion robustness, and sensitivity to frequency offset. Both analysis and simulation results show that various parameter adaptations can be made with respect to the channel state information to improve the system performance.

  • 5.
    Du, Jinfeng
    et al.
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Signell, Svante
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Novel Preamble-Based Channel Estimation for OFDM/OQAM Systems2009In: 2009 IEEE International Conference On Communications , Vols 1-8, IEEE conference proceedings, 2009, p. 4135-4140Conference paper (Refereed)
    Abstract [en]

    OFDM/OQAM has been considered as an attractive alternative to classic OFDM with cyclic prefix (CP) over doubly dispersive channels. By utilising well designed pulse shapes and removing CP, OFDM/OQAM has the advantage of reduced out-of-band energy and a theoretically higher spectral efficiency. However, channel estimation over doubly dispersive channels has been a big problem for OFDM/OQAM due to the non-orthogonality between the real and imaginary parts of its modulated signals. Therefore conventional channel estimation (CE) methods used for OFDM cannot be directly applied to OFDM/OQAM. Recently a preamble-based CE method - interference approximation method (IAM) - has been proposed to ease this task. By treating the intrinsic interference from neighbour symbols as known information, two heuristic preamble sequences have been constructed based on tentative observations, which turn out to be suboptimal. In this paper, we present a general theoretical framework for LAM preamble design and apply it to identify the optimal LAM preamble sequence which results in a higher gain. Numerical results have verified the effectiveness of the theoretical framework and a gain of 2.4 dB against CP-OFDM has been demonstrated with the new preamble in various doubly dispersive channels with a QPSK modulation.

  • 6.
    Du, Jinfeng
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Signell, Svante
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Pulse Shape Adaptivity in OFDM/OQAM Systems2008In: 2008 International Conference on Advanced Infocomm Technology, ICAIT '08, Association for Computing Machinery (ACM), 2008Conference paper (Refereed)
    Abstract [en]

    Adaptation is crucial to realise high data rate transmission in multicarrier communication systems over dispersive channels. Apart from rate/power adaptation enabled by orthogonal frequency division multiplexing (OFDM), OFDM/offset QAM (OFDM/OQAM) systems provide possibility to adjust pulse shapes depending on the channel characteristics. In this paper we discuss and evaluate pulse shape adaptivity in OFDM/OQAM systems with focus on the extended Gaussian functions (EGF) which have been shown to be good candidates for pulse shape adaptation. By investigating the time frequency dispersion robustness and carrier frequency offset sensitivity, both analysis and simulation results show that pulse shape adaptation with respect to the channel state information can improve the system performance.

  • 7.
    Du, Jinfeng
    et al.
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Signell, Svante
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Time frequency localization of pulse shaping filters in OFDM/OQAM systems2007In: 2007 6th International Conference on Information, Communications and Signal Processing, Vols 1-4, IEEE conference proceedings, 2007, p. 1406-1410Conference paper (Refereed)
    Abstract [en]

    In this paper we investigate the time frequency localization (TFL) properties of different pulse shapes in OFDM/OQAM systems. Various prototype functions, such as rectangular, half cosine, Isotropic Orthogonal Transfer Algorithm (IOTA) function and Extended Gaussian Functions (EGF) are discussed and implemented in a Matlab/Octave Simulation Workbench for Software Defined Radio by direct discretisation of the continuous time model. Simulation results show that pulse shapes with good TFL properties can have near perfect reconstruction.

  • 8. Harnefors, L.
    et al.
    Holmberg, J.
    Signell, Svante
    Suppression of overflow limit cycles in LDI all-pass/lattice filters2000In: IEEE Transactions on Circuits And Systems Part I: Fundamental Theory and Applications, ISSN 1057-7122, E-ISSN 1558-1268, Vol. 47, no 4, p. 594-598Article in journal (Refereed)
    Abstract [en]

    In this paper it is shown that zero-input overflow limit cycles can be suppressed in a class of lossless digital integrator (LDI) all-pass filters. namely, that introduced in [1], This holds for any filter order, provided that saturation overflow characteristics are used at the input of each delay and for certain restrictions for the multiplier values. The results are shown to apply also to lossless digital differentiator (LDD) filters. The restrictions of multiplier values have the effect of excluding certain combinations of poles within the unit circle, most of which are in the left half circle where corresponding LDD filters can be used. Asymptotic stability can be guaranteed for all second-order LDI and LDD filters.

  • 9.
    Huang, Jinliang
    et al.
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Signell, Svante
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    A Novel Power Allocation Strategy for Finite Alphabet in MIMO Systems2006In: 2006 IEEE 63RD VEHICULAR TECHNOLOGY CONFERENCE, VOLS 1-6, NEW YORK, NY: IEEE , 2006, p. 1835-1839Conference paper (Refereed)
    Abstract [en]

    One of the significant benefits of Multiple-Input-Multiple-Output (MIMO) for wireless applications is the high spectral efficiency it can achieve. Water filling (WF) has long been deemed as the optimal power allocation strategy to maximize the spectral efficiency. However, the high complexity of this algorithm is annoying in the case of finite alphabet. The current paper suggests a novel power allocation strategy in the context of finite alphabet that is much simpler than WE It can achieve 95% of the spectral efficiency of WF in the i.d.d. Rayleigh fading channel, and even outperform WF in highly correlated fading channel, e.g. the line-of-sight (LOS) Ricean fading channel.

  • 10.
    Huang, Jinliang
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Signell, Svante
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Adaptive MIMO systems in 2x2 uncorrelated Rayleigh fading channel2007In: 2007 IEEE WIRELESS COMMUNICATIONS & NETWORKING CONFERENCE, VOLS 1-9, NEW YORK: IEEE , 2007, p. 1115-1119Conference paper (Refereed)
    Abstract [en]

    Adaptive MQAM modulation is used to maximize spectral efficiency while keeping bit error rate (BER) under a target level. The closed-form expressions of the average spectral efficiency of adaptive modulation system are derived for beamforming (BF), singular value decomposition (SVD), Space-Time Block Coding (STBC) and spatial multiplexing with zero-forcing (ZF) receiver in uncorrelated flat Rayleigh fading channel. Further, a low-complexity adaptive scheme that switches across BF and SVD in closed loop systems, STBC and ZF in open loop systems is suggested to enhance the spectral efficiency on the basis of the closed form expressions.

  • 11.
    Huang, Jinliang
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture, Communication Systems, CoS.
    Signell, Svante
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture, Communication Systems, CoS.
    Adaptive Modulation and Power Allocation for OSTBC2009In: ICICS 2009 - Conference Proceedings of the 7th International Conference on Information, Communications and Signal Processing: Macau Fisherman's Wharf: 8 December 2009 through 10 December 2009, 2009Conference paper (Refereed)
    Abstract [en]

    Adaptive modulation and power allocation schemes have been widely used in multiple-input multiple-output(MIMO) systems to enhance spectral efficiency while maintaining bit error ratio (BER) to a target level. We derivethe spectral efficiency of orthogonal space-time block codes (OSTBC) that can be achieved by applying adaptivemodulation and power allocation. Compared to non-adaptive power scheme, the adaptive power allocation canachieve substantial gain in the spectral efficiency. Moreover, channel estimation errors are taken into account andthe impact on the spectral efficiency is investigated.

  • 12.
    Huang, Jinliang
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture, Communication Systems, CoS.
    Signell, Svante
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture, Communication Systems, CoS.
    Asymptotic Performance of MMSE MIMO Systems Using Adaptive ModulationIn: IEEE Communications Letters, ISSN 1089-7798, E-ISSN 1558-2558Article in journal (Other academic)
    Abstract [en]

    This letter investigates the asymptotic performance of minimum-mean-square error (MMSE) in MIMO systemsusing adaptive modulation. The asymptotic average spectral efficiency and bit-error rate (BER) are derived basedon three approximations of the probability density function (p.d.f.) of effective SNR. Simulations suggest that themost accurate estimation of average spectral efficiency is obtained by using Gamma distribution.

  • 13.
    Huang, Jinliang
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Signell, Svante
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Discrete rate spectral efficiency for adaptive MIMO systems2008In: ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings, 2008, p. 3089-3092Conference paper (Refereed)
    Abstract [en]

    Adaptive modulation scheme has been widely used in multiple-input multiple-output (MIMO) systems to enhance spectral efficiency while maintaining bit-error rate (BER) under a target level. We consider two MIMO schemes, orthogonal space-time block codes (OSTBC) and spatial multiplexing with zero-forcing receiver (SM-ZF), that apply adaptive modulation and derive closed-form expressions of the average spectral efficiency. Based on the closed-form expression of the average spectral efficiency, a low complexity switching method is utilized to gain significant improvement in spectral efficiency over an adaptive modulation system using a single MIMO scheme.

  • 14.
    Huang, Jinliang
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture, Communication Systems, CoS.
    Signell, Svante
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture, Communication Systems, CoS.
    Discrete rate spectral efficiency improvement by scheme switching for MIMO systems2008In: IEEE International Conference on Communications, ISSN 1550-3607, E-ISSN 1938-1883, p. 3998-4002Article in journal (Refereed)
    Abstract [en]

    Adaptive modulation scheme has been widely used in multiple-input multiple-output (MIMO) systems to enhance spectral efficiency while maintaining the bit error rate (BER) under a target level. We consider two MIMO schemes, orthogonal space-time block codes (OSTBC) and spatial multiplexing with zero-forcing receiver (SM-ZF), that apply adaptive modulation scheme and derive closed-form expressions of the average spectral efficiency and BER. Based on the closed-form expression of spectral efficiency, a low complexity switching method is utilized to obtain high spectral efficiency gain over an adaptive system using a single scheme.

  • 15.
    Huang, Jinliang
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture, Communication Systems, CoS.
    Signell, Svante
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture, Communication Systems, CoS.
    Impact of channel estimation error on performance of adaptive MIMO systems2008In: Proceedings of the IEEE International Conference on Acoustics, Speech and Signal Processing, ISSN 1520-6149, p. 2865-2868Article in journal (Refereed)
    Abstract [en]

    Adaptive modulation scheme has been widely used in multiple-input multiple-output (MIMO) systems to enhance the spectral efficiency while maintaining the bit-error-rate (BER) under a target level. In this work, we investigate the performance of adaptive modulation in the presence of imperfect channel estimation and the impact of estimation noise on the spectral efficiency. The closed-form expressions for the average spectral efficiency are derived. Two MIMO schemes are considered, i.e., orthogonal space-time block codes (OSTBC) and spatial multiplexing with zero-forcing receiver (SM-ZF), and a low complexity method to enable the transmitter to switch between OSTBC and SM-ZF is utilized to achieve higher spectral efficiency than adaptive OSTBC and adaptive SM-ZF.

  • 16.
    Huang, Jinliang
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture, Communication Systems, CoS.
    Signell, Svante
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture, Communication Systems, CoS.
    On Performance of Adaptive Modulation in MIMO Systems Using Orthogonal Space-Time Block Codes2009In: IEEE Transactions on Vehicular Technology, ISSN 0018-9545, E-ISSN 1939-9359, Vol. 58, no 8, p. 4238-4247Article in journal (Refereed)
    Abstract [en]

    We provide a systematic study of adaptive modulation schemes in multiple-input multiple-output (MIMO)orthogonal space-time block codes (OSTBC) systems. Closed-form expressions are obtained to evaluate systemperformance, e.g., average spectral efficiency, bit-error-ratio (BER), and outage probability. Provided the closedformexpressions, the optimal SNR thresholds that yield the maximal average spectral efficiency can be solved. Inorder to reduce complexity of the optimal algorithm, an original method which can achieve approximately the sameperformance as the optimal one is proposed. Furthermore, we apply these methods in a more practical situation,where channel estimation is imperfect, and examine how the performance is affected due to channel estimationerrors.

  • 17.
    Huang, Jinliang
    et al.
    KTH, School of Information and Communication Technology (ICT), Electronic Systems.
    Signell, Svante
    KTH, School of Information and Communication Technology (ICT), Electronic Systems.
    On Spectral Efficiency of Low-Complexity Adaptive MIMO Systems in Rayleigh Fading Channel2009In: IEEE Transactions on Wireless Communications, ISSN 1536-1276, E-ISSN 1558-2248, Vol. 8, no 9, p. 4369-4374Article in journal (Refereed)
    Abstract [en]

    Adaptive MQAM modulation is used to maximize spectral efficiency of Multiple-Input Multiple-Output (MIMO) systems while keeping bit error rate (BER) under a target level. Closed-form expressions of the average spectral efficiency, coined as discrete-rate spectral efficiency (DRSE), are derived for adaptive modulation MIMO systems using different algorithms. To further enhance the spectral efficiency, a low complexity adaptation scheme is suggested to switch across different algorithms based on the DRSE. In the current letter, we investigate the adaptation scheme that switches between Orthogonal Space-Time Block Codes (OSTBC) and spatial multiplexing with zero-forcing (ZF) detection for MIMO systems with two transmit antennas. Two types of operating environment are considered: flat Rayleigh fading channel without spatial correlation and spatially correlated Rayleigh fading channel with transmit correlation.

  • 18.
    Huang, Jinliang
    et al.
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Signell, Svante
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS. IEEE, Sweden .
    The application of rate adaptation with finite alphabet in MIMO-OFDM2005Conference paper (Refereed)
    Abstract [en]

    To maximize the spectral efficiency of MIMOOFDM under a certain target Bit Error Rate (BER) in an environment where alphabet is discrete and upper bounded, it is necessary to apply adaptive power control and rate adaptation to always find the maximal alphabet size it can support. Although water filling (WF) can achieve the capacity of MIMO fading channel theoretically, it is not a preferable power allocation strategy in practice when alphabet is finite. To get higher spectral efficiency, a modified power control based on water filling can be utilized. In this paper we will compare these bit-, power-loading algorithms in the scenario where instantaneous Channel State Information (CSI) is known to the transmitter. Besides, the Space-Time Block Coding (STBC) with rate adaptation is implemented and it turns out that STBC can even achieve higher spectral efficiency in some cases.

  • 19.
    Huang, Jinliang
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Signell, Svante
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    The spectral efficiency of 2 x 2 adaptive MIMO systems in spatially correlated Rayleigh fading channel2007In: Proceedings of Future Generation Communication and Networking, FGCN 2007, IEEE Computer Society, 2007, p. 244-247Conference paper (Refereed)
    Abstract [en]

    In need for high-speed data transmission over wireless channels, multiple-input multiple-output (MIMO) technology has been suggested as it exhibits significant improvement in channel capacity. In practice, adaptive modulation scheme can be applied in different MIMO algorithms to further improve the system efficiency. In this paper, we derive closed-form expressions for the spectral efficiency of MIMO system utilizing two algorithms: Orthogonal Space-Time Block Coding (OSTBC) and spatial multiplexing with zero-forcing (ZF) receiver Furthermore, a low-complexity adaptive scheme that switches between OSTBC and ZF to achieve even a higher spectral efficiency is suggested based on the closed form expressions.

  • 20.
    Larsson, Peter
    et al.
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Svante, Signell
    Antenna configuration method in communication system involves arranging antenna elements in separation that is set in relation to communication distance or communication wavelength.2003Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    NOVELTY - The method involves configuring several antenna elements by arranging them in a separation that is set in relation to communication distance or communication wavelength. USE - For antenna configuration in high data rate communication system. ADVANTAGE - Increases throughput such as transmission of data at both vertical and horizontal polarizations. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following: (1) antenna configuration; and (2) communication system. DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of the antenna configuration process.

  • 21.
    Larsson, Peter
    et al.
    Ericsson Research, Isafjordsgatan 14E, 164 93 Kista, Sweden.
    Svante, Signell
    D, ASTELY
    Method and Apparatus in a Mimo Based Communication System2003Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    NOVELTY - The communication parameters are adapted for set of user terminals based on principle used for optimizing communication with respect to partial channel state information (CSI) by singular value decomposition (SVD). The parameters for another set of terminals, are adapted based on another principle to optimize multiple input and multiple output (MIMO) communication. The parameters are then sent to respective set of terminals. USE - For communicating between user terminals in multiple input multiple output (MIMO) based communication network (claimed). ADVANTAGE - Optimized communication between the user terminals is obtained effectively. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following: (1) transmitter node; and (2) multiple input multiple output based communication network. DESCRIPTION OF DRAWING(S) - The figure shows the schematic diagram of the SVD-based MIMO system. (Drawing includes non-English language text). scheduling unit (9') feedback channels (17,19) preprocessor (91) transmitter (T4)

  • 22.
    Li, Yang
    et al.
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Signell, Svante
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Multi-Bandwidth Analog Filter Design for SDR2008In: 2008 IEEE ASIA PACIFIC CONFERENCE ON CIRCUITS AND SYSTEMS (APCCAS 2008), VOLS 1-4, NEW YORK: IEEE , 2008, p. 956-959Conference paper (Refereed)
    Abstract [en]

    Software Defined Radio (SDR) becomes more and more popular due to the requirement of multi-standard communication. In the front end, the increasing demand for multi-mode wireless communication necessitates low cost, highly integrated and multi-bandwidth analog circuits to be implemented. This paper presents an overview on the consideration of Intermediate Frequency (IF) filter design for five communication standards: GSM, WCDMA, 802.11b, 802.11g and WiMAX. A transistor level multi-bandwidth IF Gyrator-C filter is designed. Through the frequency response we can analyze the filter channel selection for different standards.

  • 23.
    Mannakkara, Chammika
    et al.
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Signell, Svante
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Software implementation of DVB-RCT modulator2006In: 2006 International Conference on Industrial and Information Systems, Vols 1 and 2, NEW YORK: IEEE , 2006, p. 463-469Conference paper (Refereed)
    Abstract [en]

    Digital Video Broadcasting-Terrestrial (DVB-T), the European terrestrial Digital TV system, is becoming popular in the broadcaster community around the world. Many countries have started terrestrial digital TV broadcast and are planning to switch-off analogue broadcasts in near future. A new set of services on DVB systems would be the key to sustain its successful commercial deployment. DVB-Return Channel Terrestrial (RCT) is a complementary standard for DVB-T which defines an interactive return channel using UBF/VHF bands. Together, DVB-T/RCT system provides a bi-directional, asymmetric, broadband wireless path between broadcasters and customers, which leads to a true terrestrial wireless interactive system. A host of interactive services are possible on such a platform including IP services. This make DVB-T/RCT a cost effective solution for providing Internet access in rural areas where the telecommunication infrastructure is not fully developed but are already covered by the terrestrial broadcast networks. In this paper, software implementation of the DVB-RCT Terminal (DVB-RCTT) is presented which was carried out as a master thesis work. In conjunction with two other master theses, the goal was to develop a prototype of DVB-RCTT for testing purposes at DVB-T/RCT test-bed in Sweden. The prototype consists of a PC running GNU/Linux, a PCI DVB-T card for the receiver and a PCI FPGA board for the modulator of the RCTT. The focus of the software implementation is on the Medium Access Control (MAC) layer of the DVB-RCTT to be executed on the GNU/Linux box. First, the MAC messaging sequences between base-station and terminal at the DVB-T/RCT test-bed were studied. A DVB-RCT MAC message analyzer was developed initially for this purpose. Based on the analysis, MAC layer for a prototype of RCTT is developed under Debian GNU/Linux OS. In order to facilitate the MAC layer communication with the RCT modulator, DVB-API is extended to the support the modulator functionality. The new DVB-RCT modulator API is implemented as a hardware independent device driver under GNU/Linux. The MAC process was tested against messaging sequences obtained at DVB-T/RCT test-bed to verify correct functionality.

  • 24. Qin, Y.
    et al.
    Chen, Q.
    Signell, Svante
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture (Closed 20120101), Communication Systems, CoS (closed 2012-01-01).
    A wide input range pipelined ADC without rail-to-rail opamp2010In: 1st International Conference on Green Circuits and Systems, ICGCS 2010, 2010, p. 424-427Conference paper (Refereed)
    Abstract [en]

    A dynamic range boosting (DRB) technique is proposed in this paper. By applying this technique, the designed pipelined analog-to-digital converter could sample a wide dynamic range analog input, which is even larger than the output swing of the opamp used in SHA and MDAC. A 13b 5MS/s pipelined A/D converter based on single stage telescopic opamps is implemented and achieves a dynamic range up to 2.4VPP, while its supply voltage is 1.8V.

  • 25.
    Qin, Yajie
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture (Closed 20120101), Communication Systems, CoS (closed 2012-01-01). Fudan University, China .
    Chen, Q.
    Signell, Svante
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture (Closed 20120101), Communication Systems, CoS (closed 2012-01-01).
    Hong, Z.
    A 50MS/s 80dB SFDR digital calibrated pipelined ADC with workload-balanced MDAC2011In: IEEE Int. Conf. Electron Devices Solid-State Circuits, EDSSC, 2011Conference paper (Refereed)
    Abstract [en]

    A workload-balanced multiplying digital-to-analog converter (WB-MDAC) is proposed to improve the settling efficiency of multi-bit pipeline stages, and demonstrated in a 14-bit 50-MS/s digital calibrated pipelined ADC. The presented ADC occupies an active area of 1.3 mm 2 in 0.13-μm 1P8M CMOS technology, including internal reference buffers. It dissipates 76mW from a 1.2-V supply, and achieves 64.4 dB SNDR and over 80 dB SFDR. 

  • 26.
    Qin, Yajie
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Chen, Qihui
    Hong, Zhiliang
    Signell, Svante R.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    A highly linear 1.2 V 12bit 5-45 MS/s CMOS pipelined ADC with CM-sensing-and-input-interchanged OTA sharing2012In: Analog Integrated Circuits and Signal Processing, ISSN 0925-1030, E-ISSN 1573-1979, Vol. 72, no 1, p. 237-241Article in journal (Refereed)
    Abstract [en]

    A 1.2 V 12bit programmable pipelined ADC is presented and implemented in 0.13 mu m CMOS technology. A common-mode-sensing-and-input-interchanged OTA-sharing technique is proposed to address the non-resetting and successive-stage crosstalk issues in conventional OTA-sharing technique. Speed options of 5-45 MS/s are available with scalable power obtained by adjusting the bias currents for OTAs, comparators, and reference buffers, etc., or the global bias current. The measured signal-to-distortion-and-noise ratio is in range of 62.5-69.2 dB, and the peak spurious free dynamic range is 80.7 dB for all speed options, while the figure-of-merit is in the range of 0.26-0.49 pJ/conversion. The core area is 1.5 mm(2).

  • 27.
    Qin, Yajie
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Hong, Z.
    Signell, Svante R.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    A 1-V switched-opamp sample-and-hold circuit for wideband wireless communication2008Conference paper (Refereed)
    Abstract [en]

    This paper presents a 1-V 10bit 50MSPS Switched-Opamp (SO) S/H circuit, designed in 3.3V/1.8V 0.18μm 1P6M CMOS technology, which could be used in wideband wireless transceivers. A new architecture of the low voltage switchable opamp with improved common-mode feed back (CMFB) loop is introduced for its fast wake-up speed. Simulation results show the S/H circuit achieves a THD of -75dB and a SFDR of 76dB at the Nyquist frequency (Fin = F s/2). The opamp only dissipates a static power of 1.9mW even in active phase.

  • 28.
    Qin, Yajie
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture (Closed 20120101), Communication Systems, CoS (closed 2012-01-01). Fudan University, China.
    Lu, B.
    Signell, Svante
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture (Closed 20120101), Communication Systems, CoS (closed 2012-01-01).
    A time-spreading calibration technique for multi-bit/stage pipeline ADCs2009In: 2009 International SoC Design Conference, ISOCC 2009, 2009, p. 416-419Conference paper (Refereed)
    Abstract [en]

    This paper describes a robust and effective calibration algorithm for pipelined analog-to-digital converters, which compensates for large gain errors, without the requirement for a long startup time as required by the other dither-based algorithms presented in literature. The proposed technique, time-spreading self-calibration, operates the front-end sample-and-hold stage in half rate at startup and cancels out the strong input-interference by using subtractive correlation, achieves a quick convergence. When the sample-and-hold stage operates in full rate as normal, the algorithm works as a background dither-based scheme and enables to calibrate time-variant gain errors. Simulation results show that it only needs wake-up time of 3 × 10 5·T s to correct a 15-bit pipelined ADC in the presence of realistic capacitor mismatch and finite op-amp gain, where T s is the sampling period.

  • 29.
    Shaber, Mezbah Uddin
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Signell, Svante
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Fully differential gain-boosted ota design for pipeline daconverter in 180NM CMOS technology2005Conference paper (Refereed)
    Abstract [en]

    This paper describes a fully differential gain-boosted improved OTA for high performance pipeline DA-converter [1], [2] in UMC 180nm technology for a 3.3V power supply applications. The architecture chosen for the design is a folded cascode OTA structure for the main and gain boosting stages. The designed OTA achieved a very high DC gain greater than 95db with a unity gain band width of 500MHz for a 500fF load with a power consumption of 14.5mW and phase margin of more then 55 degrees, which meets the design specifications. The design is meant to be used for implementation of a pipeline DA-converter, using selection inversion based on Gray coded bit vector. Simulation is done using Cadence Affirm Spectre circuit simulator. Layout of the OTA structure has been finished and prepared to be taped out.

  • 30.
    Shaber, Mezbah Uddin
    et al.
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Signell, Svante
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Pipelined DAC architecture using gray coding2005In: Norchip 2005, Proceedings, 2005, p. 141-144Conference paper (Refereed)
    Abstract [en]

    This work describes a new architecture suitable for wideband Digital to Analog converter for System-on-Chip. The architecture use switched capacitor pipelined D/A converter design with Selection Inversion based on gray coded bits. A 95dB DC-gain fully differential folded cascode gain-boosted OTA has been designed to be used in each pipelined stage. High linearity up to 61db (SFDR) is achieved for a 5MHz input sign wave at a 50MHz Update frequency. This work describes a new architecture suitable for wideband Digital to Analog converter for System-on-Chip. The architecture use switched capacitor pipelined D/A converter design with Selection Inversion based on gray coded bits. A 95dB DC-gain fully differential folded cascode gain-boosted OTA has been designed to be used in each pipelined stage. High linearity up to 61db (SFDR) is achieved for a 5MHz input sign wave at a 50MHz Update frequency.

  • 31.
    Signell, Svante
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    ADDA - A versatile development platform for AD and DA-converters2007In: 2007 Norchip, 2007, p. 104-107Conference paper (Refereed)
    Abstract [en]

    ADDA is a versatile development platform for AD-and DA- converters. It contains performance analysis algorithms for converters enabling the user to characterise converters and create data-sheets. The converters characterised are either simulated or real products. Currently characterisation and modelling of Nyquist converters are included with delta-sigma converters to follow in a future release. The platform, written in C-language, is free software released with the Gnu General Public License (GPL) and is freely available for all parties interested to contribute with models, analysis methods or measurement setups. New models of converters are easily included in the platform following included templates and the instructions in the README.

  • 32.
    Signell, Svante
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Jittered uniform sampling - Examples2005In: IEEE International Symposium on Cicuits and Systems, ISSN 0271-4302, E-ISSN 2158-1525, p. 988-991Article in journal (Refereed)
    Abstract [en]

    In many communication systems jitter is a problem causing performance degradation. The jitter is present in both analogue parts and in the sampling process. In this contribution examples of calculated and simulated spectra are shown for uncorrelated Uniform and uncorrelated and correlated Gaussian jitter distributions. Closed form expressions are also given for selected correlated noise cases. In two companion contributions, [1] random input signals and [21 deterministic input signals perturbed by jitter are analysed and the mathematical foundation to the examples given here are made. The analytical results show that the output signal spectrum consists of both discrete and continuous parts. For some applications, such as instruments for spectrum analysis, large jitter can be of great use utilizing the fact that discrete alias components can be completely removed with sufficiently large jitter.

  • 33.
    Signell, Svante
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture (Closed 20120101), Communication Systems, CoS (closed 2012-01-01).
    NETTAN: A tool for analysis and iterative design of analog-, digital- and Switched-Capacitor filters2008Conference paper (Refereed)
    Abstract [en]

    NETTAN is a versatile development platform for filter analysis and design. It contains analysis algorithms for filters enabling the user to characterise a given filter or iteratively synthesise a filter for a target specification by optimisation. Filters included are passive RLC-, active RC-, digital and Switched-Capacitor filters. The platform, written in the Fortran language, is free software released with the Gnu General Public License (GPL) version 3 or later. It is especially useful for all parties interested to contribute with new analysis and/or synthesis methods. Other uses are for educational purposes, and NETTAN can be included in any graduate course having filters as one of the course subjects. Usage of the tool is simplified by the users manual and an on-line help.

  • 34.
    Signell, Svante
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Non-traditional architectures for AD- and DA-converters2005In: ASICON 2005: 2005 6th International Conference on ASIC, Proceedings, 2005, p. 417-418Conference paper (Refereed)
    Abstract [en]

    Traditional AD-converters of cyclic or pipeline type normally use algorithms that create offset binary output code. The input sample is converted starting with the most significant bit (MSB) and ends with the least significant bit (LSB), giving a total of N bits. In cyclic converters this is achieved by one processing element resolving a number of bits, M, with the residue voltage is scaled by M and fed back to the input in a recursive manner in a loop. For pipeline converters this loop is rolled out, using one processing element for each set of M bits and using N/M processing stages. Current popular state-of-the-art converter architectures use M=1 and M=1.5, with error correction for the 1.5 bit case. Cyclic converters are normally used for medium speed operation and can be designed for extremely small silicon area and power consumption, while pipeline converters can be very high speed at the cost of more area and power consumption. Nonidealities in the processing elements, such as capacitor mismatch, amplifier and comparator offsets, signal dependent and independent charge injection, finite OTA gain- and bandwidth and noise will induce errors in the residue voltages that eventually affect the accuracy of the converter limiting its resolution [1],[2]. The errors can be both random and systematic. Normally these errors are addressed by circuit level improvements meant to reduce their magnitude. Alternately, some of the errors can be mitigated at the block level, especially the systematic errors. The use of Gray coding [3] achieves a lower accumulation of errors that depends on the bits generated. The net effect of Gray coding is to introduce only a gain difference, compared to an ideal converter. Two other alternatives are to slightly modify the Binary output code, by alternating the residue error sign at each cycle [4],[5], or alternate the sign for the MSB residue voltage [4]],[6]. These modifications improve the performance by several bits compared to traditional Binary coded converters. These improvements are obtained at no extra hardware cost, since only complementary binary outputs are needed, which are already available for fully differential realizations. For DA-converters the concept of cyclic and pipelined converters can easily be obtained, by reversing the operations for the ADC algorithms. The resulting DACs start with the LSB and the conversion is completed when the MSB is processed, either in a cyclic manner or pipelined. The input signal can be Binary coded, alternate Binary coded or Gray coded [7]-[9]. Substantial performance improvements are achievable also for DACs at the block level by modifying the digital input code format in a similar manner as for ADCs. Traditional high-performance DACs are normally built as two-stage converters, using one coarse and one fine stage using combinations of R2R ladders and Binary weighted current sources. The outputs are for most designs a current. In order to achieve low thermal noise the terminating resistor is small, resulting in a large power consumption. The techniques described above allow one to use voltages as outputs, giving potential advantages in power consumption. This paper gives a brief overview of the alternate architectures for ADCs and DACs using simple algorithm modifications at the block level and the possible performance improvements are motivated and verified.

  • 35.
    Signell, Svante
    et al.
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Huang, Jinliang
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    A matlab/octave simulation workbench for multi-antenna software defined radio2006In: 24th Norchip Conference, Proceedings / [ed] Johansson, T, IEEE , 2006, p. 145-148Conference paper (Refereed)
    Abstract [en]

    The current paper describes a generic workbench for multiple antennas Software Defined Radio (SDR) system in Matlab or Octave. The workbench is functionally modularized and make use of parameter lists for reconfiguration. Currently, it supports both narrow band MIMO systems and OFDM-based wideband systems with single or multiple antennas. It could also be easily extended to accommodate other wireless or wireline standards, such as GSM, WCDMA, xDSL, DVB-x, Wimax, Bluetooth, etc.

  • 36.
    Signell, Svante
    et al.
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Huang, Jinliang
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    A simulation environment for multi-antenna Software Defined Radio2007In: 2007 6th International Conference on Information, Communications and Signal Processing, Vols 1-4, 2007, p. 1328-1331Conference paper (Refereed)
    Abstract [en]

    This paper describes a generic simulation workbench for multiple antenna Software Defined Radio (SDR) systems in MATLAB or OCTAVE, for both Windows and Unix/Linux operating systems. The workbench is functionally modularized into blocks and sub-blocks with a common interface for the convenience of modification and reconfiguration. Currently, it accommodates a variety of transmission schemes, including single-carrier multiple-input multiple-output (MIMO), Orthogonal Frequency-Division Multiplexing (OFDM), multi-carrier MIMO, Wideband Code Division Multiple Access (WCDMA), filtered multitone (FMT), which have extensive applications in modern communication technologies, e.g., WLAN 802.11 a/b/g/n, WiMAX, UWB, 3G cellular network, ADSL, DVB, etc.

  • 37.
    Signell, Svante R.
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture, Communication Systems, CoS.
    Huang, Jinliang
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture, Communication Systems, CoS.
    LiLaS: A Link Layer Simulator in Matlab/Octave2009In: MSWIM09; PROCEEDINGS OF THE 12TH ACM INTERNATIONAL CONFERENCE ON MODELING, ANALYSIS, AND SYSTEMS, NEW YORK: ASSOC COMPUTING MACHINERY , 2009, p. 143-146Conference paper (Refereed)
    Abstract [en]

    This paper describes a generic link layer simulation environment for multiple antenna systems in MATLAB and OCTAVE, for both Windows and Unix/Linux operating systems: LiLaS. The simulator is functionally divided into modules, sub-modules and models with a common interface for the convenience of modification and reconfiguration. Currently, it accommodates a variety of transmission schemes, including single-carrier and multiple-carrier MIMO, Orthogonal Frequency-Division Multiplexing (OFDM), OFDM/Offset QAM, Wideband Code Division Multiple Access (W-CDMA), filtered multitone (FMT) and RFID which have extensive applications in modern communication technologies, e.g.. WLAN 802.11 a/b/g/n, WiMAX, UWB, 3G, LTE, LTE advanced, IMT advanced, xDSL, DVB, etc.

  • 38.
    Signell, Svante
    et al.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Rodríguez de Llera González, Delia
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Ismail, Mohammed
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Radio design for future wireless SOC platforms: An overview2004In: 22ND NORCHIP CONFERENCE, PROCEEDINGS, NEW YORK: IEEE , 2004, p. 277-280Conference paper (Refereed)
    Abstract [en]

    As we move to third and fourth generation wireless providing higher data rates at shorter distances in "hotspots", future handhelds will be able to access different wireless infrastructures, e.g. UMTS and WLAN, from the same wireless device, be it a mobile phone, a PDA or a notebook. As a result SoC platforms for convergent 4G must address the challenge of increased complexity particularly as it pertains to the radio transceiver part of a chipset where power consumption and cost are the main differentiators. This paper presents an overview of the challenges faced in designing highly integrated radios in the context of 4G wireless communications. Aside from important issues such as multi antenna design and standards coexistence in the same SoC platform, we focus our overview on a few main thrusts that will be discussed in some details related to designing digitally programmable and con gurable ADCs, PLLs, analog baseband chains and RF front ends as well as techniques for packaging multi band radios and for achieving " rst pass" silicon success.

  • 39.
    Signell, Svante
    et al.
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Shaber, Mezbah Uddin
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    High-speed pipelined DAC architecture using Gray coding2006In: 2006 IEEE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS, VOLS 1-11, PROCEEDINGS, NEW YORK, NY: IEEE , 2006, p. 113-116Conference paper (Refereed)
    Abstract [en]

    This work describes a new architecture suitable for wide-band Digital to Analog Converters (DACs) for System-on-Chip. The architecture use a switched capacitor pipelined D/A converter design with selection inversion based on Gray coded bits. A 95dB DC-gain fully differential folded cascode gain-boosted OTA to be used in each pipelined DAC bit cell has been designed. Two bit Switched-Capacitor cells have been analysed, one amplifier offset-compensated version and one high-speed version. High linearity up to 64dB SFDR is achieved for a 1MHz input sine wave at a 10MHz update frequency of the first DAC bit cell and 20MHz update frequency for the second DAC bit cell. The speed limiting factor is the switch sizes, not the amplifier bandwidths.

  • 40.
    Signell, Svante
    et al.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Sun, Yi-Ran
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Jitter Performance of Reconstruction Algorithmsfor Nonuniform Bandpass Sampling2003In: Proceedings of EuropeanConference of Circuit Theory and Design (ECCTD), Krakow,Poland, September 2003., 2003, p. 353-356Conference paper (Refereed)
  • 41.
    Sun, Yi Ran
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Signell, Svante R.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Effects of Noise and Jitter in Bandpass Sampling2005In: ANALOG INTEGRATED CIRCUITS AND SIGNAL PROCESSING, 2005, Vol. 42, no 1, p. 85-97Conference paper (Refereed)
    Abstract [en]

    BandPass Sampling (BPS) is an undersampling technique by intentional aliasing. BPS enables one to have an interface between the IF stage and the ADC in a radio receiver. Conventional uniform BPS at Nyquist rate normally results in a low Signal-to-Noise Ratio (SNR) due to noise spectrum aliasing. The noise (e.g. kT/C noise introduced in a voltage-mode sampler) is combined in each of the Nyquist bands within the bandwidth of the sampling device. Also timing jitter causes a performance degradation in BPS. In this paper, signal spectrum aliasing, noise aliasing and jitter effects in BPS is analyzed. It is verified by simulation that NonUniform Sampling (NUS) has the potential to suppress signal spectrum aliasing and relax the requirement on the anti-aliasing (AA) filter. Jitter effects in BPS are compared to LowPass Sampling (LPS) case. However, a signal cannot be reconstructed from its nonuniform samples by using only ideal lowpass filtering (classic Shannon's reconstruction). Finally, signal reconstruction in the presence of noise and jitter are investigated for three Reconstruction Algorithms (RAs) aimed at NUS.

  • 42.
    Sun, Yi-Ran
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Signell, Svante
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    A Generalized Quadrature Bandpass Sampling in Radio Receivers2005In: 10th Asia and South Pacific Design Automation Conference Shanghai, PEOPLES R CHINA, JAN 18-21, 2005, 2005, p. 1288-1291Conference paper (Refereed)
    Abstract [en]

    Bandpass sampling (BPS) realizes frequency down-conversion by undersampling. Noise aliasing as the direct consequence of the lower sampling rate causes a performance degradation. In this paper, a generalized quadrature BPS (GQBPS) combined with a filter which performs both reconstruction and bandpass filtering is studied in the frequency domain with respect to both signal reconstruction and noise aliasing reduction. The theoretical analyses show that GQBPS might be a potential way to reduce noise aliasing at the cost of a more complicated reconstruction algorithm.

  • 43.
    Sun, Yi-Ran
    et al.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Signell, Svante
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    A Generalized Quadrature Bandpass Samplingwith Noise Aliasing Suppression2004In: Workshop on Wireless Circuits andSystems (WoWCAS),Vancouver B.C., Canada, May 2004, 2004, p. 41-42Conference paper (Refereed)
  • 44.
    Sun, Yi-Ran
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Signell, Svante
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    A Novel Quadrature BandpassSampling in SDR Front-Ends2004In: Proceeding of Biennial Analog Signal ProcessingConference, (ASP 2004), Oxford: Oxford Brookes University , 2004Conference paper (Refereed)
    Abstract [en]

    In this paper, a Generalized Quadrature BandPass Sampling (GQBPS) and inherent FIR filteringare briefly reviewed. Both theoretical analysis and simulation results show that this inherentFIR filtering not only has the advantage of image and interference rejection, but also is helpfulto suppress noise aliasing. A realizable implementation by uniform quadrature BPS (UQBPS)shows promise to sufficiently suppress the noise aliasing in BPS systems.

  • 45.
    Sun, Yi-Ran
    et al.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Signell, Svante
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Algorithms for Nonuniform Bandpass Sampling in Radio Receiver2003In: PROCEEDINGS OF THE 2003 IEEE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS, VOL I - ANALOG CIRCUITS AND SIGNAL PROCESSING, 2003, p. 1-4Conference paper (Refereed)
    Abstract [en]

    Bandpass Sampling (BPS) technique enables one to have an interface between IF stage and ADC in a radio receiver. Nonuniform BPS has the potential to suppress aliasing without care of the information band position of a modulated signal. However, a signal cannot be reconstructed from its nonuniform samples by using only an ideal lowpass filter. In this paper, a filter is, generalized to a reconstruction algorithm (RA). Six different algorithms for reconstructing a signal from its nonuniform samples are summarized. A general reconstruction formula in terms of a basis-kernel (BK) function is used to describe the algorithms. Finally, with regard to. the application of radio communications, accuracy of reconstruction, computational complexity and hardware implementation are shown and compared for these algorithms.

  • 46.
    Sun, Yi-Ran
    et al.
    KTH, School of Information and Communication Technology (ICT).
    Signell, Svante
    KTH, School of Information and Communication Technology (ICT).
    Analysis and Implementation of Uniform Quadrature Bandpass Sampling2005In: 2005 IEEE WORKSHOP ON SIGNAL PROCESSING SYSTEMS: DESIGN AND IMPLEMENTATION (SIPS), 2005, p. 137-142Conference paper (Refereed)
    Abstract [en]

    Sampling noise folding causes a large SNR degradation at the output of BandPass Sampling (BPS) system. A sampling architecture based on Generalized Quadrature BandPass Sampling (GQBPS) was proposed in [1]. Theoretical analysis showed that such architecture is promising to reduce the SNR degradation due to noise aliasing. In this paper, Uniform Quadrature BandPass Sampling (UQBPS) as a special case of GQBPS is analyzed for both ideal sampling and a sample-and-hold. One available implementation method to UQBPS is shown and discussed at the circuit level.

  • 47.
    Sun, Yi-Ran
    et al.
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Signell, Svante
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Effects of Noise and Jitter on Algorithms for Bandpass Sampling in Radio Receiver2004In: 2004 IEEE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS, VOL 1, PROCEEDINGS, 2004, Vol. 1, p. 1761-1764Conference paper (Refereed)
    Abstract [en]

    BandPass Sampling (BPS) is an undersampling technique by intentional aliasing. Conventional uniform discrete sampling within an f(s) band normally results in a bad signal-to-noise ratio (SNR) due to signal spectrum aliasing. The noise combined in each of the f(s) bands below the highest frequency of the signal (the so called noise spectrum aliasing) and timing jitter are two causes of performance degradation in BPS system. Nonuniform BPS has the potential to suppress signal spectrum aliasing due to the aperiodic property of NonUniform Sampling (NUS). In this paper, the frequency spectra of Uniform Sampling (US) and NUS are analyzed, signal spectrum aliasing, noise spectrum aliasing and jitter effects in BPS are studied. Finally, the performance of reconstruction algorithms (RAs) for nonuniform BPS in the presence of sources of performance degradation are discussed based on simulations.

  • 48.
    Sun, Yi-Ran
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Signell, Svante
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Filtering Transformation in GeneralizedQuadrature Bandpass Sampling2005In: Electronics, Circuits and Systems, 2005. ICECS 2005. 12th IEEE International Conference on Electronics, Circuits and Systems (ICECS), Tunis, Tunisia, December2005., 2005, p. 1-4Conference paper (Refereed)
    Abstract [en]

    According to recent research, Generalized Quadrature BandPass Sampling (GQBPS) with FIR filtering is promising to deal with the noise aliasing problem in subsampling systems. However, the interesting band of folded spectra by GQBPS with real FIR filtering is still located at the input carrier frequency. In this paper, inherent FIR filtering in GQBPS with real coefficients is transformed such that the interesting band is shifted to a lower frequency. The main advantage of such transformation is to achieve a frequency downconversion besides sampling and dealing with noise aliasing in GQBPS. As a special case of GQBPS, Uniform Quadrature BandPass Sampling (UQBPS) is also discussed including the filter transformation. Both theoretical analyses and simulations are included. It is verified that the expected noise aliasing improvement of GQBPS or UQBPS does not change with the filter transformation. The whole subsampling system with GQBPS or UQBPS might be simplified by using complex filtering.

  • 49.
    Sun, Yi-Ran
    et al.
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Signell, Svante
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Generalized bandpass sampling with complex FIR filtering2006In: 2006 IEEE Asia Pacific Conference on Circuits and Systems, NEW YORK: IEEE , 2006, p. 1035-1038Conference paper (Refereed)
    Abstract [en]

    In this paper, Generalized Quadrature BandPass Sampling (GQBPS) with complex FIR filtering is studied with respect to both noise and jitter. GQBPS is a type of nonuniform sampling, and has been extended to Generalized Uniform BandPass Sampling (GUBPS). It is shown that GQBPS and GUBPS with complex FIR filtering perform both down-conversion and noise aliasing suppression in addition to sampling. Due to the averaging operation of FIR filtering, sampling jitter is also reduced to a certain degree by GQBPS and GUBPS. However, the performance by GQBPS is limited by the maximum effective sampling rate determined by the fixed time resolution of the sampling scheme. In contrast GUBPS avoids this problem.

  • 50.
    Sun, Yi-Ran
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Signell, Svante
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Generalized Quadrature Bandpass Sampling with FIR Filtering2005In: 2005 IEEE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS (ISCAS), VOLS 1-6, CONFERENCE PROCEEDINGS, 2005, p. 4429-4432Conference paper (Refereed)
    Abstract [en]

    In this paper, generalized quadrature BandPass Sampling (BPS) in voltage-mode with inherent FIR filtering is presented. By using the theory of sampling equivalence, this sampling strategy is comparable to another strategy, charge sampling with intrinsic IIR filtering. The theoretical analysis and simulation results show that this inherent FIR filtering not only has the advantage to reject or attenuate images and interferences, but is also helpful to suppress noise aliasing. A realizable implementation of the proposed sampling strategy by uniform quadrature BPS (UQBPS) promises to suppress noise aliasing in BPS systems to a large extent.

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