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Sum-Rate Maximization in the Multicell MIMO multiple-Access Channel with Interference Coordination

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2014年第1期13卷 36-48页

作者： Nguyen, Duy H. N. Tho Le-Ngoc McGill Univ Dept Elect & Comp Engn Dept Elect Engn Montreal PQ H3A 0E9 Canada

This paper is concerned with the maximization of the weighted sum-rate (WSR) in the multicell MIMO multiple access channel (MAC). We consider a multicell network operating on the same frequency channel with multiple mobile stations (MS) per cell. Assuming the interference coordination mode in the multicell network, each base-station (BS) only decodes the signals for the MSs within its cell, while the inter-cell transmissions are treated as noise. Nonetheless, the uplink precoders are jointly optimized at MSs through the coordination among the cells in order to maximize the network weighted sum-rate (WSR). Since this WSR maximization problem is shown to be nonconvex, obtaining its globally optimal solution is rather computationally complex. Thus, our focus in this work is on low-complexity algorithms to obtain at least locally optimal solutions. Specifically, we propose two iterative algorithms: one is based on successive convex approximation and the other is based on iterative minimization of weighted mean squared error. Both solution approaches shall then reveal the structure of the optimal uplink precoders. In addition, we also show that the proposed algorithms can be implemented in a distributed manner across the coordinated cells. Simulation results show a significant improvement in the network sum-rate by the proposed algorithms, compared to the case with no interference coordination.

关键词： Multicell interference coordination coordinated multipoint transmission/reception multiple-input multiple-output multiple access channel convex optimization MMSE

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Hybrid genetic crossover based swarm intelligence optimization for efficient resource allocation in MIMO OFDM systems

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Research Journal of Applied Sciences, Engineering and Technology 2015年第7期10卷 742-749页

作者： Sathish Kumar, B. Shankar Kumar, K.R. Department of Electronics and Communication Engineering Sri Ramakrishna Engineering College Coimbatore Tamil Nadu 641022 India Department of Electronics and Communication Engineering Ranganathan Engineering College Coimbatore Tamil Nadu 641109 India

Rapid development of wireless services, leads to ubiquitous personal connectivity in the world. The demand for multimedia interactivity is higher in the world which leads to the requirement of high data transmission rate. multiple-input multiple-output Orthogonal Frequency Division multiplexing (MIMO-OFDM) is a future wireless service which is used to overcome the existing service problems such as development of subscriber pool and higher throughput per user. Although it overcomes the problems in existing services, resource allocation becomes one of the major issues in the MIMO-OFDM systems. Resource allocation in MIMO-OFDM is the optimization of subcarrier and power allocation for the user. The overall performance of the system can be improved only with the efficient resource allocation approach. The user data rate is increased by efficient allocation of the subcarrier and power allocation for each user at the base station, which is subject to constraints on total power and bit error rate. In this study, the problem of resource allocation in MIMO-OFDM system is tackled using hybrid artificial bee colony optimization algorithm based on a crossover operation along with Poisson-Jensen in equation. The experimental results show that the proposed methodology is better than the existing techniques. © Maxwell Scientific Organization, 2015.

关键词： Genetic crossover operator Hybrid artificial bee colony optimization multiple-input multiple-output Orthogonal frequency division multiplexing Swarm intelligence

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Joint Source-Relay Optimization for Fixed Receivers in Multi-Antenna Multi-Relay Networks

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2014年第1期13卷 62-74页

作者： Ikhlef, Aissa Schober, Robert Univ British Columbia Dept Elect & Comp Engn Vancouver BC V6T 1Z4 Canada

We jointly optimize the source and relay precoders for multi-antenna multi-relay networks employing a prefixed receiver. Prefixed receivers are of practical interest since they enable low complexity at the end-user's receiver as well as backward compatibility. To compute the source and relay precoders, we consider two different criteria. The objective of the first criterion is to maximize the worst stream signal-to-interference-plus-noise ratio (SINR) at the output of the receiver subject to source and relay transmit power constraints. Under the second criterion, we minimize the source and relay transmit powers subject to a certain quality-of-service constraint. Both optimization problems are non-convex. To solve them, we propose iterative alternating algorithms, where, in each iteration, we compute the precoders alternately, i.e., for each precoder optimization, we fix all the precoders except the one which is optimized. For both criteria, we formulate the optimization problem for the computation of the source precoder as a second order cone programming (SOCP) problem, for which the optimal solution can be found using interior point algorithms. For each relay precoder, we formulate the optimization problem as a semidefinite relaxation (SDR) problem for which ready-to-use solvers exist. If the solution to the SDR problem is not of rank one, matrix rank-one decomposition or randomization is applied. We also provide sufficient conditions for the convergence of the proposed iterative alternating algorithms to a fixed point. Simulation results show that the performance of the proposed algorithms is close to the performance achieved if the source, relay, and receiver filters are jointly optimized.

关键词： Cooperative relaying multiple-input multiple-output joint optimization of source and relays prefixed receivers

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BER analysis of DPSK-SIM over MIMO free space optical links with misalignment

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OPTIK 2014年第18期125卷 5176-5180页

作者： Prabu, K. Kumar, D. Sriram NIT Dept Elect & Commun Engn Tiruchirappalli 620015 Tamil Nadu India

Free-space optics (FSO) is a safe, license-free, high speed and high-bandwidth cordless technique for broadcasting signals at the same speed as fiber optics. But the main drawback of FSO is the dissolution of the signals due to atmospheric turbulence and thus degrading the link performance. So, to enhance the bit error rate (BER) performance, spatial diversity is employed over the FSO links for single-input multiple-output FSO (SIMO-FSO) systems. In this paper, we analyze the BER performance of SIMO-FSO links with spatial diversity and multiple-input multiple-output FSO (MIMO-FSO) systems over gamma-gamma atmospheric turbulence fading channel with misalignment (pointing errors). The closed form expressions are derived for the same with various combining schemes in terms of the Meijer G function and also evaluate the results with 2D and 3D graphs. (C) 2014 Elsevier GmbH. All rights reserved.

关键词： Free space optics Differential phase shift keying subcarrier intensity modulation Strong atmospheric turbulence Pointing errors Single-input multiple-output multiple-input multiple-output

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Efficient and low complexity modulation classification algorithm for MIMO systems

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Research Journal of Applied Sciences, Engineering and Technology 2015年第1期9卷 58-64页

作者： Bahloul, Mohammad Rida Yusoff, Mohd Zuki Saad, M. Naufal M. Department of Electrical and Electronic Engineering Universiti Teknologi PETRONAS Tronoh Perak 31750 Malaysia

This study develops a feature-based Automatic Modulation Classification (AMC) algorithm for spatially multiplexed multiple-input multiple-output (MIMO) systems employing two Higher Order Cumulants (HOCs) of the estimated transmit signal streams as discriminating features and a multiclass Support Vector Machine (SVM) as a classification system. The algorithm under study has the capability to recognize a wide range of modulation schemes without any prior information about the channel state. The classification performance of the proposed algorithm was evaluated via extensive simulations under different operating conditions and was also compared with the one obtained with the optimal Hybrid Likelihood Ratio Test (HLRT) approach. The results show that the proposed algorithm is capable of classifying the considered modulation schemes with good classification accuracy and can achieve performance comparable to that of the HLRT approach while having a significantly lower computational complexity. © Maxwell Scientific Organization, 2015.

关键词： Automatic modulation classification Higher-order cumulants multiple-input multiple-output Support vector machine

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BER analysis of BPSK-SIM-based SISO and MIMO FSO systems in strong turbulence with pointing errors

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OPTIK 2014年第21期125卷 6413-6417页

作者： Prabu, K. Kumar, D. Sriram Malekian, Reza Natl Inst Technol Dept Elect & Commun Engn Tiruchirappalli 620015 Tamil Nadu India Univ Pretoria Dept Elect Elect & Comp Engn ZA-0002 Pretoria South Africa

Free space optics (FSO) is one of the sprouting technologies in optical communication systems domain. It can be employed as an alternative for the conventional radio frequency (RF) links to work out the current limitations in communication systems. But, the major drawback in FSO communication is the effect of random environment conditions on its performance. In this paper, we analyze the bit error rate (BER) and outage performance of single-input single-output (SISO) and multiple-input multiple-output (MIMO) FSO systems in strong atmospheric turbulence using binary phase shift keying subcarrier intensity modulation (BPSK-SIM) signaling technique. The closed-form expressions are derived and the results are realized in terms of 2D and 3D plots. (C) 2014 Elsevier GmbH. All rights reserved.

关键词： Free space optics Bit error rate Outage probability Single-input single-output multiple-input multiple-output

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MIMO radar antenna array synthesis with a hybrid approach based on GA and PSO

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INTERNATIONAL JOURNAL OF EMBEDDED SYSTEMS 2014年第2-3期6卷 108-113页

作者： Dong, Jian Jiang, Yi Liu, Fang Zhu, Xuanzi Shi, Ronghua Cent South Univ Sch Informat Sci & Engn Changsha 410000 Hunan Peoples R China

This study proposes a hybrid approach to synthesise the MIMO radar antenna arrays with low peak side lobe levels (PSLLs). In this approach, the positive features of genetic algorithm (GA) and particle swarm optimisation (PSO) have been integrated to find the optimal array arrangements. Also, in order to avoid prematurity in GA process, an improved adaptive operator is adopted for the adaptive adjustment of crossover probability and mutation probability. The simulation validation, carried out on the synthesised pattern of MIMO radar, shows that, the optimal PSLLs and convergence performance have been achieved by the hybrid approach compared to GA and PSO, respectively.

关键词： multiple-input multiple-output MIMO thinned array genetic algorithm particle swarm optimisation PSO adaptive operator

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Millimeter Wave Communications With Symmetric Uniform Circular Antenna Arrays

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IEEE COMMUNICATIONS LETTERS 2014年第8期18卷 1307-1310页

作者： Wang, Peng Li, Yonghui Vucetic, Branka Univ Sydney Sch Elect & Informat Engn Sydney NSW 2006 Australia

This letter is concerned with the singular value characterization of fixed point-to-point millimeter wave channels with symmetric uniform circular antenna arrays (UCAs) at both the transmitter and receiver. We model the channel as a line-of-sight (LoS) multiple-input multiple-output (MIMO) one and derive an explicit expression for all channel singular values. The asymptotic analysis when the end-to-end distance or the number of antenna elements goes to infinity is then developed. Numerical examples are provided to verify the validity of our discussions. The results in this letter show that the achievable multiplex gain is limited under such a system setting, regardless of the numbers of antennas at the transmitter/receiver. This observation provides benchmarks for the practical performance of UCA-based gigabits wireless communications over millimeter wave channels.

关键词： Millimeter wave line-of-sight multiple-input multiple-output uniform circular antenna arrays

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Secure Beamforming Design for Physical Layer Network Coding Based MIMO Two-Way Relaying

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IEEE COMMUNICATIONS LETTERS 2014年第7期18卷 1270-1273页

作者： Jayasinghe, Keeth Jayasinghe, Praneeth Rajatheva, Nandana Latva-Aho, Matti Univ Oulu Dept Commun Engn Oulu 90014 Finland

In this letter, we propose a secure beamforming scheme for physical layer network coding (PNC)-based multiple-input multiple-output (MIMO) two-way relaying system. The relay node performs PNC mapping. An eavesdropper is attempting to intercept the user information. The channel state information (CSI) of the user-to-eavesdropper channel is imperfect at the user nodes. A robust optimization problem is formulated to design beamforming vectors at the user nodes and relay. The problem is non-convex, and an algorithm is proposed to solve that. In the numerical analysis, we discuss the convergence of the proposed algorithm and the impact of the CSI error on the performance.

关键词： multiple-input multiple-output physical layer network coding physical layer security

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Eight-element antenna array for diversity and mimo mobile terminal in LTE 3500 MHz band

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MICROWAVE AND OPTICAL TECHNOLOGY LETTERS 2014年第6期56卷 1323-1327页

作者： Al-Hadi, Azremi Abdullah Ilvonen, Janne Valkonen, Risto Viikari, Ville Aalto Univ Sch Elect Engn Dept Radio Sci & Engn Espoo 02150 Finland Univ Malaysia Perlis Sch Comp & Commun Engn Kangar 01000 Perlis Malaysia Univ Kiel Inst Elect & Informat Engn D-24143 Kiel Germany

A multiantenna system comprising of an eight-element antenna array in mobile terminal is presented. In this work, two sets of eight-element antenna structures based on capacitive coupling element and inverted-F antennas operating at 3400-3600 MHz long-term evolution frequency band are designed. The structures are estimated to achieve a good effective diversity gain in both uniform and nonuniform environments. It is also shown that the proposed structures achieve an ergodic multiple-input multiple-output (MIMO) capacity of only 1.2 bit/(s Hz) lower than the capacity achieved by ideal uncorrelated antennas. A prototype is fabricated to validate the simulation results. The result shows that the structure exhibited the highest mutual coupling of -10 dB across the required frequency band. Therefore, the proposed structure is a good candidate for implementing diversity and MIMO in mobile terminals. (c) 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1323-1327, 2014

关键词： mutual coupling antenna diversity multiple-input multiple-output multielement antenna mobile terminal antenna

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