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Dual-Layered MIMO Transmission for Increased Bandwidth Efficiency

IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2016年第5期65卷 3139-3149页

作者： Masouros, Christos Hanzo, Lajos UCL Dept Elect & Elect Engn London WC1E 7JE England Univ Southampton Sch Elect & Comp Sci Southampton SO17 1BJ Hants England

A dual-layered downlink transmission scheme is proposed for intrinsically amalgamating multiple-input-multiple-output (MIMO) spatial multiplexing (SMX) with spatial modulation (SM). The proposed scheme employs a classic SMX transmission that is known to offer superior bandwidth efficiency (BE) compared with SM. We exploit receive-antenna-based SM (RSM) on top of this transmission as an enhancement of the BE. The RSM here is applied to the combined spatial and power-level domain not by activating and deactivating the RAs but rather by choosing between two power levels {P-1, P-2} for the received symbols in these antennas. In other words, the combination of symbols received at a power level P-1 carries information in the spatial domain in the same manner as the combination of nonzero elements in the receive symbol vector carries information in the RSM transmission. This allows for the coexistence of RSM with SMX, and the results show increased BE for the proposed scheme compared with both SMX and SM. To characterize the proposed scheme, we carry out a mathematical analysis of its performance, and we use this to optimize the ratio between P-1 and P-2 for attaining the minimum error rates. Our analytical and simulation results demonstrate significant BE gains for the proposed scheme compared with conventional SMX and SM.

关键词： multiple-input-multiple-output systems spatial modulation (SM) spatial multiplexing (SMX) transmit precoding (TPC)

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Passive wireless local area network radar network using compressive sensing technique

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IET RADAR SONAR AND NAVIGATION 2015年第1期9卷 84-91页

作者： Weiss, Matthias Fraunhofer FHR PSR D-53343 Wachtberg Germany

Distributed networks constructed from heterogeneous or homogeneous sensors, which are also called multiple-input-multiple-output systems, offer several advantages compared to single sensor systems. In particular for a distributed homogeneous sensor network targets are illuminated from various aspect angles and reflections are received at different locations simultaneously. Hence, these networks outperform single-input-single-output systems easily by several aspects. This spatial diversity improves target detection and parameter estimation dramatically. Therefore these radar networks attract more and more scientists worldwide. This study shows the potential of compressive sensing technique applied to a distributed homogeneous sensor network comprised of several wireless local area network routers as transmitters and dedicated receivers. The CS group sparsity approach is employed to reduce the required data rate, which has to be transferred to a central processing unit for data fusion, without decreasing the performance of the sensor network.

关键词： wireless LAN passive radar compressed sensing MIMO communication electromagnetic wave reflection object detection wireless sensor networks telecommunication network routing radar transmitters radar receivers radar network compressive sensing technique heterogeneous sensors multiple-input-multiple-output systems distributed homogeneous sensor network single-input–single-output systems target detection spatial diversity passive wireless local area network routers transmitters receivers CS group sparsity approach data fusion

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Look-ahead sphere decoding: algorithm and VLSI architecture

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IET COMMUNICATIONS 2011年第9期5卷 1275-1285页

作者： Gamba, M. T. Masera, G. Politecn Torino Dipartimento Elettron I-10129 Turin Italy

multiple-input-multiple-output (MIMO) systems are recognised as a key enabling technology in high-performance wireless communications;however, the implementation of high-throughput MIMO detectors still is a critical task. Among known MIMO detectors, sphere decoder algorithm (SDA) is capable of optimal performance with acceptable processing complexity. The study presents an improved SDA, which enables significant throughput increase at a very limited additional complexity and with no degradation in terms of bit error rate performance. The modified detection method, called LASDA (look-ahead SDA), is based on formal algorithm transformations, namely look-ahead, retiming and pipelining, and requires a modified tree search strategy. The VLSI design of LASDA detector supporting a 4 x 4 MIMO channel with 16 QAM modulation is detailed in the study for a 130 nm CMOS standard cell technology: synthesis results show that the proposed solution achieves an average throughput of 380 Mbps at a signal-to-noise ratio of 22 dB (Rayleigh fading channel), with an occupied silicon area of 0.18 mm(2). Comparisons with a number of previous implementations are also provided.

关键词： size 130 nm multiple-input-multiple-output systems signal-to-noise ratio error statistics Codes search problems high-performance wireless communications high-throughput MIMO detectors Other topics in statistics quadrature amplitude modulation wireless channels MIMO channel look-ahead SDA Combinatorial mathematics decoding trees (mathematics) CMOS standard cell technology bit error rate performance look-ahead sphere decoding QAM modulation modified detection method VLSI design Radio links and equipment CMOS integrated circuits LASDA VLSI MIMO communication modified tree search strategy

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6.2 GHz 0.5 mW two-dimensional oscillator array-based injection-locked frequency divider in 0.18 μm CMOS

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ELECTRONICS LETTERS 2015年第1期51卷 62-63页

作者： Yu, Xiaopeng Song, Xiong Lim, Wei Meng Yeo, Kiat-Seng Zhejiang Univ Hangzhou 310027 Peoples R China Nanyang Technol Univ Sch Elect & Elect Engn Singapore 639798 Singapore

A new two-dimensional oscillator array-based injection-locked frequency divider is proposed. Instead of using the conventional analogue tuning technique or the one-dimensional delay chain, a two-dimensional array is implemented to digitally and precisely control the total delay in the oscillator core. This makes it possible to achieve a programmable delay, hence attaining potential programmable division ratios for the injection-locked divider. Fabricated in a standard 0.18 mu m CMOS technology, a prototype chip, namely a divide-by-4/5 prescaler using this technique, is able to work up to 6.2 GHz with 0.5 mW power consumption from a 1.8 V supply voltage.

关键词： singular value decomposition MIMO communication array signal processing iterative methods channel estimation SVD singular value decomposition channel estimation optimal beamforming vector pair MIMO channel matrix MP-SVE right singular vectors left singular vectors SNR signal-to-noise ratio multiple-input-multiple-output systems MIMO beamforming matching pursuit-based singular vectors estimation

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Smart antennas for wireless communications beyond the third generation

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COMPUTER COMMUNICATIONS 2003年第1期26卷 41-45页

作者： Haardt, M Spencer, Q Ilmenau Univ Technol Commun Res Lab D-98684 Ilmenau Germany

Smart antennas are essential to increase the spectral efficiency of wireless communication systems. They can be realized by an antenna array at the base station and sophisticated base-band signal processing. Thereby, adaptive directional reception is achieved on the uplink and adaptive directional transmission on the downlink if channel knowledge is available at the transmitter. Hence, an increased antenna gain and an increased diversity gain are realized towards the desired user. At the same time, less interference is received from the other directions on the uplink or transmitted in the other directions on the downlink if channel knowledge is available at the transmitter. Therefore, more users can be accommodated by the system and a corresponding increase of the spectral efficiency is achieved. Even higher spectral efficiencies can be obtained if antenna arrays are not only used at the base station but also at the mobile. The theoretical capacity of such multiple-inputmultiple-output systems has been shown to grow linearly with the size of the antenna arrays in sufficiently rich multi-path environments. Open problems in this new area of wireless communications include better and more realistic propagation models as well as improved algorithms for transmission and reception which approach the theoretical limits of the channel. (C) 2002 Elsevier Science B.V. All rights reserved.

关键词： smart antennas beamforming space-time codes multiple-input-multiple-output systems space-time processing spatial channel models Wireless World Research Forum

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PCI-MF: Partial Canonical Identity and Matrix Factorization Framework for Channel Estimation in mmWave Massive MIMO systems

IEEE OPEN JOURNAL OF SIGNAL PROCESSING

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IEEE OPEN JOURNAL OF SIGNAL PROCESSING 2020年 1卷 135-145页

作者： Jain, Neha Bohara, Vivek Ashok Gupta, Anubha Indraprastha Inst Informat Technol Dept Elect & Commun Engn IIIT D New Delhi 110020 India Wirocomm Res Grp Delhi 110020 India Signal Proc & Biomed Imaging Lab SBILab Delhi 110020 India

Beamforming using massive number of antennas in millimeter wave (mmWave) communication is a promising solution for providing gigabits-per-second data rates in cellular networks. However, perfect channel state information (CSI) estimation is a key requirement, which is not practically feasible in massive multiple-input-multiple-output (MIMO) systems. Hence, compressive sensing (CS) and matrix completion methods have been proposed in the literature to reduce the channel estimation overhead. In this paper, a novel method utilizing partial canonical identity (PCI) based CS and matrix factorization (MF) framework, henceforth termed as PCI-MF, has been proposed to recover complete mmWave CSI by estimating only a few channel coefficients. Specifically, a few estimated noisy channel coefficients are represented as a combination of PCI and discrete Fourier transform (DFT) matrix in a CS framework to recover the sparsest solution of the channel matrix. This framework exploits the fact that both PCI and DFT matrices are highly incoherent. The sparse matrix determined above has been used to recover the rank of the channel matrix. The knowledge of the rank, along with the sparse coefficients recovered above, have been used jointly in a matrix factorization framework to recover the actual channel matrix. PCI-MF has been compared with the conventional and the state-of-the-art methods for two different datasets by varying parameters such as the number of transmitting and receiving antennas, antenna configuration, signal-to-noise ratio and measurement ratio. In order to validate the proposed method for realistic applications, one dataset is generated in a real-world setting in the New York City.

关键词： Millimeter wave beamforming multiple-input-multiple-output systems partial canonical identity matrix discrete Fourier transform matrix factorization

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A Frequency Domain Pre-Equalizer for MIMO-OFDM Mobile Communication systems Employing Alamouti Coding

A Frequency Domain Pre-Equalizer for MIMO-OFDM Mobile Commun...

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12th IEEE International Workshop on Signal Processing Advances in Wireless Communications

作者： Baracca, P. Benvenuto, N. Vangelista, L. Univ Padua Dept Informat Engn I-35100 Padua Italy

ISBN: (纸本)9781424493326

Orthogonal frequency division multiplexing (OFDM) is a very popular modulation scheme because it requires a very simple receiver in transforming a frequency-selective channel into multiple flat-fading channels. Furthermore, multiple-input-multiple-output (MIMO) OFDM systems employing transmit diversity techniques, such as space-time (ST) and space-frequency (SF) coding, increase robustness and reliability over wireless fading channels. However, time-variation of the channel due to mobility disrupts orthogonality among subcarriers and yields intercarrier interference (ICI), limiting the performance of OFDM. In this paper we first recall a reduced-complexity technique to mitigate ICI in single-input-single-output (SISO) OFDM systems denoted per sub-block equalization (PSE) which operates on sub-blocks of the received OFDM symbol. Next we propose an extension of PSE to MIMO SF-OFDM systems. In particular, the Alamouti scheme is used in conjunction with PSE to combat ICI. Performance of the proposed scheme is evaluated for mobile digital video broadcasting DVB-T2 2 x 1 and 2 x 2 MIMO scenarios that suit with a possible extension to handheld devices in a next generation DVB-H. Numerical results show that the new receiver provides a gain from 21% to 33% with respect to the conventional OFDM receiver in terms of vehicular speed at which a target bit error rate can be maintained.

关键词： Alamouti coding Bit error rate Decoding Digital video broadcasting ICI MIMO MIMO communication MIMO-OFDM mobile communication system OFDM OFDM modulation PSE Receiving antennas SF SISO ST bit error rate digital video broadcasting digital video broadcasting DVB-T2 diversity reception diversity techniques equalisers error statistics fading channels frequency domain preequalizer intercarrier interference intercarrier interference interference suppression mobile communication multiple flat-fading channels multiple-input-multiple-output systems orthogonal frequency division multiplexing per subblock equalization reduced-complexity technique single-input- single-output space-frequency coding space-time coding

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The Effect of Convolutional Encoder Memory on The Sphere Decoding Search Radius in MIMO systems

The Effect of Convolutional Encoder Memory on The Sphere Dec...

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21st Signal Processing and Communications Applications Conference (SIU)

作者： Karakus, Oktay Altinkaya, Mustafa A. Kilicaslan, Kagan Izmir Yuksek Teknol Enstitusu Elekt Elekt Muhendisligi Bolumu Izmir Turkey

ISBN: (纸本)9781467355636;9781467355629

In the new generation communication systems multiple-input-multiple-output systems are frequently used. The processing load of the Maximum Likelihood (ML) Detector which is the optimum detector for these systems, increases exponentially as a function of system dimension and memory due to testing all possible points. Sphere Decoding (SD) method which tests only the probable points, decreases the processing load dramatically. System memory changes by system dimensions and length of the convolutional encoder. This, in turn, affects the radius of the hyper sphere centered at the observation in the observation space at which SD attains the performance of the ML detector. This effect is investigated via simulation studies. In these simulations, it is observed that the radius of the SD is relatively smaller than the one in ML, and the ratio between the radius values varies from 6,61 in the case of memoryless 2x2 MIMO system to 1,02 in the case of 8x8 MIMO system with memory K=10 according to increased antenna numbers and system memory. In addition to these, it is observed that the radius of the hyper sphere is directly proportional to the memory of the encoder.

关键词： multiple-input-multiple-output systems Maximum Likelihood Sphere Decoding Convolutional Encoder

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Bandwidth Efficient Spatial Modulation by Signalling in the Power Domain

Bandwidth Efficient Spatial Modulation by Signalling in the ...

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IEEE International Conference on Communications (ICC)

作者： Masouros, Christos Hanzo, Lajos UCL Dept Elect & Elect Engn London WC1E 6BT England Univ Southampton Sch Elect & Comp Sci Southampton SO9 5NH Hants England

ISBN: (纸本)9781479966646

We explore a bandwidth efficient transmission scheme that amalgamates multiple-input-multiple-output spatial multiplexing (SMX) with receive antenna based spatial modulation (RSM). The RSM here is applied to the combined spatial and power-level domain, not by activating and de-activating the receive antennas, but rather by choosing between two power levels {P-1, P-2} for the received symbols in these antennas, such that all receive antennas are active and SMX can still be accommodated. This allows for the coexistence of RSM with SMX and the results show an increased bandwidth efficiency for the proposed scheme compared to both SMX and RSM. We further carry out a mathematical analysis to optimize the ratio between P1 and P2 for attaining the minimum error rates. Our analytical and simulation results demonstrate significant bandwidth efficiency gains for the proposed scheme compared to conventional SMX and RSM.

关键词： Spatial modulation spatial multiplexing multiple-input-multiple-output systems transmit precoding

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Simultaneous Application of Adaptive PID Controller and Smith Dead-time Predictor Rule in Nonlinear Water Level Control in Neka Power Plant

Simultaneous Application of Adaptive PID Controller and Smit...

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6th IEEE Conference on Industrial Electronics and Applications (ICIEA)

作者： Mehrafrooz, Arash Sorkhkolaei, Meghdad Roohi Yazdizadeh, Alireza Power & Water Univ Technol PWUT Fac Elect Engn Tehran Iran Islamic Azad Univ Cent Tehran Branch Fac Engn Tehran Iran

ISBN: (纸本)9781424487554

In this paper, a novel adaptive PID-like controller is introduced. Compared to the conventional methods, better responses are achieved by using the proposed method. The proposed controller is based on neural networks technology and is applied to different kind of black box systems, linear or nonlinear systems and time variant and/or time invariant systems. Generally speaking, it is known that classical tuning methods for PID controllers provided unsatisfactory results for industrial plants where the time delay exceeds the dominant lag time;that is the reason for studying alternative strategies. In this context the most popular rule is Smith predictor. Generally, dead time is a variable parameter and leads to changing the model of system during process of control. Therefore we need to estimate this variable parameter using an online algorithm. We have done and proven this estimation via Smith rule for different systems with first order or second order models. In order to show the actual performances of mentioned methods, we have run them on the level control of tanks in water refinement process of Neka power plant which generally is a very nonlinear and delayed system. In order to control this system we apply our neural networks controller and Smith predictor rule simultaneously. Simulation results in this chapter show the perfect performance of our adaptive controllers and rules.

关键词： Neural Networks PID Controllers Multi-variable systems Fluid level Control Nonlinear Control multiple-input-multiple-output systems

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