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An MTL-Based Channel Model for Indoor Broadband MIMO Power Line Communications

IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS 2016年第7期34卷 2045-2055页

作者： Corchado, Julio A. Cortes, Jose A. Canete, Francisco J. Diez, Luis Univ Malaga Dept Ingn Comunicac Escuela Tecn Super Ingn Telecomunicac E-29071 Malaga Spain

The recent release of indoor power line communication (PLC) standards with multiple-input multiple-output (MIMO) capabilities has led to the need for channel models that reflect the multiconductor nature of the grid. This paper proposes a model, based on the multiconductor transmission line theory, along with a random PLC channel generator operating in the frequency range from 1 to 100 MHz. Its distinctive features are the modeling of three key elements: the asymmetry in the layout caused by the derivations to the light switches, the impedance of the devices connected to the three wires of the grid, and the variable distance between the conductors in loose wiring deployments. The influence of these elements in the spatial correlation between the streams of the MIMO links is studied and compared with measurements.

关键词： Power line communications multiple-input multiple-output broadband spatial correlation multiconductor transmission line channel modeling

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Performance analysis of MIMO-OFDM free space optical communication system with low-density parity-check code

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PHOTONIC NETWORK COMMUNICATIONS 2016年第1期32卷 104-114页

作者： Sharma, Manish Chadha, D. Chandra, Vinod Indian Inst Technol Dept Elect Engn New Delhi 110016 India

In this paper, we have evaluated the performance of a low-density parity-check (LDPC)-coded multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) free space optical (FSO) communication system. Closed form expressions for the average bit error rate and throughput with diversity using equal gain combining have been obtained for the system under consideration. The Monte Carlo simulation has been carried out for the verification of the results. The performance of the QPSK and 16 QAM modulations is evaluated for different weather and atmospheric turbulence conditions. The results are also compared for both, QPSK and 16 QAM for SISO-OFDM, and MIMO-OFDM FSO communication system. The results show that the performance of the system under consideration improves, as we move from SISO-OFDM to MIMO-OFDM. The results also show that the effect of weather is very much pronounced on the system and the performance in terms of average bit error rate of QPSK is better than 16 QAM in the presence of every weather condition. However, the later provides better throughput. Regular LDPC codes with code rate 1/2 have been applied to the simulated results, yielding high coding gains. Coding gain of 29.5 and 22 dB is achieved for QPSK and 16 QAM, respectively, for MIMO-OFDM.

关键词： Average bit error rate Free space optical communication Low-density parity-check codes multiple-input multiple-output Orthogonal frequency division multiplexing

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Experimental Verification of Signal Quality Difference Induced by Differential Modal Loss and Modal Crosstalk on Optical MIMO Transmission and its Compensation by Equipartition multiplexing

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JOURNAL OF LIGHTWAVE TECHNOLOGY 2016年第3期34卷 918-927页

作者： Mori, Takayoshi Sakamoto, Taiji Wada, Masaki Yamamoto, Takashi Yamamoto, Fumihiko Nakajima, Kazuhide NTT Corp Access Network Serv Syst Labs Tsukuba Ibaraki 3050805 Japan

We investigate experimentally the signal quality difference induced by differential modal loss and modal crosstalk (XT) in few-mode fiber during optical MIMO transmission. We measure the modal loss and modal XT properties of two LP mode fibers in the presence of tension and confirm that the coexistence of differential modal loss and modal XT leads to a signal quality imbalance even with MIMO digital processing. In addition, to compensate for the signal quality imbalance, we employ a novel equipartition multiplexing technique at the transmitter used in a mode-division-multiplexed transmission to equalize the mode-dependent impairment, and successfully achieve a two LP mode multiplexed transmission with a low signal quality difference.

关键词： Few-mode fibers multiple-input multiple-output

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Performance evaluation of applied Alamouti scheme on IEEE 802.15.4 network

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INTERNATIONAL JOURNAL OF SENSOR NETWORKS 2016年第1期22卷 58-66页

作者： Halim, Eddy Hartono Shin, Soo Young Kumoh Natl Inst Technol Dept IT Convergence Gumi 730701 Gyeongbuk South Korea Kumoh Natl Inst Technol Sch Elect Engn Gumi 730701 Gyeongbuk South Korea

This study evaluated the performance of IEEE 802.15.4 network in the case of applying Alamouti scheme using both 2 x 1 multiple-input single-output (MISO) and 2 x 2 multiple-input multiple-output (MIMO) antenna configurations. The modulation curves, i.e., bit error rate (BER) vs. signal-to-noise ratio (SNR) of the conventional IEEE 802.15.4, switching diversity, Alamouti scheme are obtained first. Using the modulation curves, performance of IEEE 802.15.4 network is investigated. Throughput, probability of successful transmission and energy efficiency are used as measures of performance. Simulations are performed to prove the effectiveness of applied Alamouti scheme in the viewpoint of IEEE 802.15.4 network.

关键词： Alamouti scheme IEEE 802.15.4 network MIMO multiple-input multiple-output throughput energy efficiency

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Performance Comparison of Massive MIMO and Conventional MIMO Using Channel Parameters 2

Performance Comparison of Massive MIMO and Conventional MIMO...

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2nd IEEE International Conference on Wireless Communications, Signal Processing and Networking (WiSPNET)

作者： Pappa, M. Ramesh, C. Kumar, Madhushri N. CMR Inst Technol Dept Elect & Commun Bangalore Karnataka India CMR Inst Technol Dept Telecommun Bangalore Karnataka India

ISBN: (纸本)9781509044429

multiple-input multiple-output (MIMO) technology is becoming mature in wireless communication systems. It has led to third and fourth generation wireless systems, which has been providing good range, reliability and higher data rates. For the increased demand of much higher data rates, coverage, spectral efficiency, capacity and reduced latency, the evolution of the next generation i.e.., the fifth generation technology is necessary. Massive MIMO technology is one of the most promising solution for the above-mentioned challenge. In massive MIMO, the base station is incorporated with hundreds to thousands of antenna array wherein the degrees of freedom can be exploited and the energy can be efficiently used due to the fact that the extra antennas at the base station helps focus the energy into the smaller regions of space. To reap the benefits provided by the extra antennas, the channel information is necessary which makes it possible to have a reliable communication. Therefore, to acquire the channel knowledge, channel state information is required at the base station and estimating the channel parameters plays an important role. In this paper, we concentrate on estimating the channel parameters for conventional MIMO and massive MIMO based on training-based and blind channel estimation techniques wherein the performance of both is compared.

关键词： Massive MIMO multiple-input multiple-output orthogonal frequency division multiplexing channel estimation training-based channel estimation blind channel estimation

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Fiber Twisting- and Bending-Induced Adiabatic/Nonadiabatic Super-Mode Transition in Coupled Multicore Fiber

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JOURNAL OF LIGHTWAVE TECHNOLOGY 2016年第4期34卷 1228-1237页

作者： Sakamoto, Taiji Mori, Takayoshi Wada, Masaki Yamamoto, Takashi Yamamoto, Fumihiko Nakajima, Kazuhide NTT Corp Access Networks Serv Syst Labs Tsukuba Ibaraki 3050805 Japan

The characteristics of power transfer between super-modes in coupled multicore fiber are investigated numerically and experimentally. We reveal that fiber twisting and macrobending cause mode coupling through an adiabatic/nonadiabatic process, which is different from the mode coupling caused by structural perturbation, namely microbending. We also investigate the impulse response characteristics of coupled two-core fibers, and find that there is an optimum core pitch for minimizing the complexity of the MIMO processing. Finally, we conduct a 4 x 4 MIMO transmission experiment using two-core fibers to evaluate their transmission characteristics. We show that strongly coupled multicore fiber can reduce the quality difference between the received signals even when the transmission line has large core-dependent gain/loss values.

关键词： Differential mode delay multi-core fiber multiple-input multiple-output super-mode

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Phase-Rotation-Aided Relay Selection in Two-Way Decode-and-Forward Relay Networks

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IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2016年第5期65卷 2922-2935页

作者： Cao, Ruohan Gao, Hui Lv, Tiejun Yang, Shaoshi Huang, Shanguo BUPT Inst Informat Photon & Opt Commun Beijing 100876 Peoples R China BUPT Sch Informat & Commun Engn Beijing 100876 Peoples R China Univ Southampton Sch Elect & Comp Sci Southampton SO17 1BJ Hants England

This paper proposes a relay selection (RS) scheme that aims to improve the end-to-end symbol error rate (SER) performance of a two-way relay network (TWRN). The TWRN consists of two single-antenna sources and multiple relays employing a decode-and-forward (DF) protocol. It is shown that the SER performance is determined by the minimum decision distance (DD) observed in the TWRN. However, the minimum DD is likely to be made arbitrarily small by channel fading. To tackle this problem, a phase rotation (PR)-aided RS scheme is proposed to enlarge the minimum DD, which, in turn, improves the SER performance. The proposed PR-based scheme rotates the phases of the transmitted symbols of one source and of the selected relay according to the channel state information (CSI), aiming for increasing all DDs to be above a desired bound. The lower bound is further optimized by using a MaxMin-RS criterion associated with the channel gains. It is demonstrated that the PR-aided MaxMin-RS approach achieves full diversity gain and improved array gain. Furthermore, compared with the existing DF-based schemes, the proposed scheme allows more flexible relay antenna configurations.

关键词： Beamforming decode-and-forward (DF) full diversity multiple-input multiple-output network coding relay selection (RS)

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A low-complexity hybrid algorithm based on particle swarm and ant colony optimization for large-MIMO detection

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EXPERT SYSTEMS WITH APPLICATIONS 2016年 50卷 66-74页

作者： Mandloi, Manish Bhatia, Vimal Indian Inst Technol Indore Discipline Elect Engn Indore 453441 Madhya Pradesh India

With rapid increase in demand for higher data rates, multiple-input multiple-output (MIMO) wireless communication systems are getting increased research attention because of their high capacity achieving capability. However, the practical implementation of MIMO systems rely on the computational complexity incurred in detection of the transmitted information symbols. The minimum bit error rate performance (BER) can be achieved by using maximum likelihood (ML) search based detection, but it is computationally impractical when number of transmit antennas increases. In this paper, we present a low-complexity hybrid algorithm (HA) to solve the symbol vector detection problem in large-MIMO systems. The proposed algorithm is inspired from the two well known bio-inspired optimization algorithms namely, particle swarm optimization (PSO) algorithm and ant colony optimization (ACO) algorithm. In the proposed algorithm, we devise a new probabilistic search approach which combines the distance based search of ants in ACO algorithm and the velocity based search of particles in PSO algorithm. The motivation behind using the hybrid of ACO and PSO is to avoid premature convergence to a local solution and to improve the convergence rate. Simulation results show that the proposed algorithm outperforms the popular minimum mean squared error (MMSE) algorithm and the existing ACO algorithms in terms of BER performance while achieve a near ML performance which makes the algorithm suitable for reliable detection in large-MIMO systems. Furthermore, a faster convergence to achieve a target BER is observed which results in reduction in computational efforts. (C) 2015 Elsevier Ltd. All rights reserved.

关键词： Particle swarm optimization Ant colony optimization Zero forcing Minimum mean squared error multiple-input multiple-output Maximum likelihood Bit error rate

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Joint CIR, CFO, DCO and FI/FS Rx IQ imbalance estimation

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IET COMMUNICATIONS 2016年第15期10卷 2025-2033页

作者： Ali, Muhammad Asim Arif, Muhammad Kumar, Wanod Sukkur Inst Business Adm Fac Engn Sukkur Pakistan Mehran Univ Engn & Technol Biomed Engn Jamshoro Pakistan Mehran Univ Engn & Technol Elect Engn Jamshoro Pakistan

The aim of this study is to design a receiver architecture which can jointly estimate the frequency selective (FS) channel impulse response (CIR), frequency independent (FI)/FS Receiver (Rx) Inphase Quadrature (IQ) imbalance, carrier frequency offset (CFO) and direct current offset using long training sequences. All of these problems are typical for low-cost radio-frequency front-ends. This study proposes a set of two scalable solutions to estimate CFO, whereas FS CIR and FI/FS Rx IQ imbalance are estimated in tandem through a closed-form expression. A low-complexity single stage equaliser is also proposed which can mitigate the effects of CFO and equalise the CIR along with FI/FS IQ imbalance in a single step. The proposed solutions are also extended to multiple-input-multiple-output-orthogonal frequency division multiplexing systems. The simulation results illustrate that solutions proposed in this study provide an excellent performance/complexity trade-off.

关键词： MIMO communication OFDM modulation channel estimation radio receivers transient response channel impulse response joint CIR carrier frequency offset joint CFO direct current offset joint DCO frequency selective frequency independent FI FS Rx IQ imbalance estimation receiver architecture design radio frequency front-ends closed-form expression multiple-input multiple-output orthogonal frequency division multiplexing systems

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Transmit Precoded Spatial Modulation: Maximizing the Minimum Euclidean Distance Versus Minimizing the Bit Error Ratio

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2016年第3期15卷 2054-2068页

作者： Yang, Ping Guan, Yong Liang Xiao, Yue Di Renzo, Marco Li, Shaoqian Hanzo, Lajos Univ Elect Sci & Technol China Natl Key Lab Sci & Technol Commun Chengdu 611731 Sichuan Peoples R China Nanyang Technol Univ Sch Elect & Elect Engn Singapore 639798 Singapore Univ Paris 11 Lab Signals & Syst L2S Orsay France Univ Southampton Sch Elect & Comp Sci Southampton SO17 1BJ Hants England

In this paper, we investigate a pair of transmit precoding (TPC) algorithms conceived for spatial modulation (SM) systems communicating over flat-fading multiple-input multiple-output (MIMO) channels. In order to retain all the benefits of conventional SM, we design the TPC matrix to be diagonal and introduce two design criteria for optimizing the elements of the TPC matrix. Specifically, we first investigate a TPC design based on maximizing the minimum Euclidean distance d(min) (max-d(min)) between the SM signal points at the receiver side. A closed-form solution of the optimal max-d(min)-based TPC matrix is derived. Then, another TPC design algorithm is proposed for directly minimizing the bit error ratio (BER) upper bound of SM, which is capable of jointly optimizing the overall Euclidean distance between all received signal points. In the minimum BER (min-BER)-based TPC algorithm, the theoretical gradient of the BER with respect to the diagonal TPC matrix is derived and a simplified iterative conjugate gradient (SCG) algorithm is invoked for TPC optimization. Our simulation results demonstrate that the proposed max-d(min)-based TPC algorithm is optimal in terms of the minimum distance. However, increasing d(min) does not achieve a further BER improvement. We also confirm that the min-BER-based TPC outperforms the max-d(min)-based TPC schemes in terms of the achievable BER performance.

关键词： Minimum Euclidean distance minimum BER multiple-input multiple-output pre-coding technique spatial modulation

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