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Experimental investigation of MIMO relay channels statistics and capacity based on wideband outdoor measurements at 2.3. GHz

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Science china(Information Sciences) 2011年第9期54卷 1945-1956页

作者： NIE Xin 1,2,ZHANG JianHua 1,2,LIU ZeMin 1 & ZHANG Ping 1,2 1 key laboratory of universal {3. communications,ministry of education beijing university of Posts and telecommunications,beijing 100876,china 2 {3. Technology Innovation Institute,beijing university of Posts and telecommunications,beijing 100876,china key laboratory of universal {3. communications Ministry of Education Beijing University of Posts and Telecommunications Beijing China wireless Technology Innovation Institute Beijing University of Posts and Telecommunications Beijing China

Relay,which serves to enhance the performance of future communication networks,is one of the most promising techniques for IMT-Advanced *** potential performance improvement of relay is investigated in this *** investigation consists of two *** the first step,to obtain a better understanding of the fundamental properties of relay channels,we conducted outdoor measurements at 2.3. GHz with 50 MHz bandwidth in a typical urban area of *** links constituting the relay transmission,i.e.,the link between base station and relay station,the link between relay station and mobile station and the link between base station and mobile station were measured by employing a real-time channel *** main factors that affect the MIMO channel capacity,i.e.,the channel gain and effective degrees of freedom,are *** cross-polarization discrimination was obtained by utilizing space-alternating generalized expectation-maximization *** channel parameters of the three links are statistically analyzed and *** the second step,based on the measured data,the performance of different relaying schemes,i.e.,amplify-and-forward and decode-and-forward,is *** impact of RS antenna configuration on the capacity is also *** measurement and evaluation results reveal that the relay can significantly improve the system coverage and performance.

关键词： MIMO relay channels IMT-Advanced frequency band channel characteristics relay performance evaluation

Error exponents for two-hop Gaussian multiple source-destination relay channels

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Science china(Information Sciences) 2012年第2期55卷 348-359页

作者： DENG PanLiang1,3.LIU YuanAn1,3.XIE Gang2,3.WANG XiaoYu1,3.TANG BiHua1,3.& SUN JianFeng1,3.1School of Electronic Engineering,beijing university of Posts and telecommunications,{3.,china 2School of Information and Communication Engineering,beijing university of Posts and telecommunications,{3.,china 3.10} laboratory of universal {13. Communication,ministry of education,{3.,china School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing China key laboratory of universal {3. Communication Ministry of Education Beijing China School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing China

We investigate the two-hop multiple source-destination relay channels using the rate splitting trans-mission scheme where each source can split its message into private and public *** determine the system error probability via integrated exponent function under amplify-and-forward(AF)and decode-and-forward(DF)relay *** most significant difference between AF and DF system error probability evaluations lies in a minimized cut-set bound of transmission rate under the DF *** are many cases among transmission rate intervals for different system parameters(*** power)and it is extremely complex to derive the system error probability for the DF *** obtain a relatively simple result,which unifies various cases by a few *** results show that the system error probability decreases with the increase of the public ***,in order to draw deep insight into the reliability requirement of each source node in this network,we provide the error exponent region(EER)for different source nodes to show the trade-off of error probability among source nodes.

关键词： error exponent error exponent region rate splitting multiple source-destination relay channel

Robust Tomlinsion-Harashima precoding design with outdated CSIT

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The Journal of china Universities of Posts and telecommunications 2010年第2期17卷 59-62页

作者： WANG Xu-zhen ,NIU Kai,HE Zhi-qiang,YU Guang-wei,WU Wei-ling key laboratory of universal {3. communications,ministry of education,beijing university of Posts and telecommunications,beijing 100876,china key laboratory of universal {3. communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

The channel state information at transmitter （CSIT） acquisition plays a key role in the multi-input multi-output （MIMO） system, especially for the precoding schemes. However it is unrealizable to acquire perfect CSIT in practice. In this article, an effective and practical dynamic CSIT model is introduced to acquire imperfect channel state information. For practicability, the channel temporal and spatial correlations are considered and the channel estimate and its error covariance are obtained by utilizing the outdated channel state information. Based on the dynamic CSIT mode, closed-form solution of robust Tomlinsion-Harashima precoding （THP） is derived by a Lagrangian approach. Numerical simulations are presented to demonstrate the performance.

关键词： channel estimation imperfect CSIT robust THP

EXIT analysis of M-algorithm based MIMO detectors and LDPC code design optimization

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Science in china(Series F) 2009年第12期52卷 2248-2258页

作者： YOU MingHou1,2, TAO XiaoFeng1,2, CUI QiMei1,2 & ZHANG Ping1,2 1 wireless Technology Innovation Institute, beijing university of Posts and {3., beijing 100876, china 2 key laboratory of universal wireless communications, (beijing university of Posts and {3.), ministry of education, beijing 100876, china wireless Technology Innovation Institute Beijing University of Posts and Telecommunications Beijing China key laboratory of universal {3. communications (Beijing University of Posts and Telecommunications) Ministry of Education Beijing China

This paper investigates joint design and optimization of both low density parity check （LDPC） codes and M-algorithm based detectors including iterative tree search （ITS） and soft-output M-algorithm （SOMA） in multiple-input multiple-output （MIMO） systems via the tool of extrinsic information transfer （EXIT） charts. First, we present EXIT analysis for ITS and SOMA. We indicate that the extrinsic information transfer curves of ITS obtained by Monte Carlo simulations based on output log-likelihood rations are not true EXIT curves, and the explanation for such a phenomenon is given, while for SOMA, the true EXIT curves can be computed, enabling the code design. Then, we propose a new design rule and method for LDPC code degree profile optimization in MIMO systems. The algorithm can make the EXIT curves of the inner decoder and outer decoder match each other properly, and can easily attain the desired code with the target rate. Also, it can transform the optimization problem into a linear one, which is computationally simple. The significance of the proposed optimization approach is validated by the simulation results that the optimized codes perform much better than standard non-optimized ones when used together with SOMA detector.

关键词： MIMO systems iterative receiver LDPC codes code optimization EXIT charts M-algorithm

Adaptive subcarrier and bit allocation based on ant colony optimization

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The Journal of china Universities of Posts and telecommunications 2010年第6期17卷 59-64页

作者： ZHAO Ying-hong,XU Xiao-dong,HAO Zhi-jie,TAO Xiao-feng wireless Technology Innovation Institute,key laboratory of {3. wireless Communication,ministry of education,beijing university of Posts and telecommunications,beijing 100876,china wireless Technology Innovation Institute Key Laboratory of Universal Wireless Communication Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

The problem of resource allocation in multiuser orthogonal frequency division multiplexing （OFDM） system is a combinatorial optimization problem,difficult to obtain optimal solutions in polynomial time. For the sake of reducing complexity,it can be solved either by relaxing constraints and making use of linear algorithms or by metaheuristic methods. In this paper,an algorithm based on ant colony optimization （ACO）,which is a typical algorithm of metaheuristic methods,is proposed for the problem,utilizing excellent search performance of ACO to obtain good solutions. In addition,a parameter is applied to balance the efficiency and fairness of resource allocation. Performance analysis between algorithms based on ACO and genetic algorithm （GA） is carried out,indicating that the proposed algorithm based on ACO outperforms traditional linear algorithms as well as GA in the system throughput with assurance of fairness simultaneously,being as a promising technology for OFDM resource allocation.

关键词： ACO OFDM GA

Data-aided synchronization algorithm dispensing with searching procedures for UWB communications

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Science china(Information Sciences) 2012年第4期55卷 778-788页

作者： REN ZhiYuan 1,JIANG Ting1,ZHONG Yi 2 & ZHAO ChengLin 1 1 key laboratory of universal {3. communications,ministry of education of china {3. Network laboratory,beijing university of Posts and telecommunications,beijing 100876,china 2 School of Information Engineering,North china university of Technology,beijing 100041,china key laboratory of universal {3. communications Ministry of Education of China wireless Network laboratory Beijing University of Posts and Telecommunications Beijing China School of Information Engineering North China University of Technology Beijing China

Rapid and accurate synchronization constitutes a major challenge in deploying Ultra-Wideband impulse radio (UWB-IR) for indoor wireless *** paper develops a data-aided (DA) synchro-nization algorithm dispensing with searching procedures for UWB-IR *** adopting a stream of alternating orthogonal pulses,frame-level synchronization can be achieved without channel ***-out utilizing any searching procedure,the timing offset estimator is obtained in a closed *** exhaustive search can be avoided,both computational complexity and synchronization time are *** and comparisons are provided to illustrate the advantages of our design over the alternatives.

关键词： Ultra-Wideband impulse radio synchronization dispensing with searching procedures searching space data-aided estimation

Novel resource allocation algorithms for multiuser downlink MIMO-OFDMA of FuTURE B3. systems

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Progress in Natural Science:Materials International 2009年第9期19卷 1141-1146页

作者： Qiaoyun Sun, Hui Tian *, Shuang Wang, Kun Dong, Ping Zhang key laboratory of universal {3. Communication, ministry of education, {3. Technology Innovation Institute, beijing university of Posts & telecommunications, beijing 100876, china key laboratory of universal {3. Communication Ministry of Education Wireless Technology Innovation Institute Beijing University of Posts & Telecommunications Beijing 100876 China

In this paper, subcarrier and power allocation problems for multiuser downlink MIMO-OFDMA of the FuTURE B3. TDD system are investigated. For the reciprocity of the TDD channel, the channel state information can be employed at the transmitter, thus eigen beamforming can be implemented efficiently. With the goal of minimizing the total transmit power under the condition that the QoS requirement of each user can be guaranteed, a novel dynamic resource allocation scheme is proposed to exploit the multiuser diversity gain. The proposed algorithm involves adaptive subcarrier allocation, adaptive modulation and eigen beamforming and achieves significant improvement in overall system performance. Based on the proposed scheme, a modified bit and power allocation is developed. The modified scheme reduces the computational complexity at little expense of system performance. Numerical simulations show that the proposed algorithm and the modified scheme can decrease the total transmit power effectively.

关键词： Adaptive modulation and coding Dynamic resource allocation Eigen beamforming MIMO–OFDMA

Performance evaluation of channel inversion precoding for downlink multi-user MIMO system

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The Journal of china Universities of Posts and telecommunications 2009年第5期16卷 20-24页

作者： CHEN Zhi-yong , WANG Wen-bo, PENG Mu-gen, LI Ren wireless Signal Processing and Network laboratory, key laboratory of universal wireless Communication, ministry of education, beijing university of Posts and telecommunications, beijing 100876, china wireless Signal Processing and Network laboratory Key Laboratory of Universal Wireless Communication Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

In downlink multi-user multi-input multi-output （MU-MIMO） system, not every user （user equipment （UE）） can calculate accurately signal to interference and noise ratio （SINR） without prior knowledge of the other users＇ precoding vector. To solve this problem, this article proposes a channel inversion precoding scheme by using the lower bound of S1NR and zero-forcing （ZF） algorithm. However, the SINR mismatch between lower bound SINR and actual SINR causes the inaccurateness of adaptive modulation and coding （AMC）. As a result, it causes degradation in performance. Simulation results show that channel inversion precoding provides lower throughput than that of single user multi-input multi-output （SU-MIMO） at high signal-to-noise ratio （SNR）（〉14 dB）, due to the SINR mismatch, although the sum-rate of channel inversion precoding is higher than that of SU-MIMO at full SNR regime.

关键词： MU-MIMO channel inversion precoding CQI feedback AMC lower bound S1NR zero-forcing

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屏蔽二进阵列偶的构造方法研究

通信学报 2008年第7期29卷 1-6页

作者：蒋挺施炯周正北京邮电大学泛网无线通信教育部重点实验室北京100876

准最佳、双准最佳屏蔽二进阵列偶具有良好周期相关特性,是对最佳屏蔽二进阵列偶的扩充。为深入完善屏蔽二进阵列偶理论,在最佳二进阵列偶、准最佳和双准最佳二进阵列偶构造方法研究的基础上,给出了3.最佳、准最佳、双准最佳屏蔽二进阵... 详细信息

准最佳、双准最佳屏蔽二进阵列偶具有良好周期相关特性,是对最佳屏蔽二进阵列偶的扩充。为深入完善屏蔽二进阵列偶理论,在最佳二进阵列偶、准最佳和双准最佳二进阵列偶构造方法研究的基础上,给出了3.最佳、准最佳、双准最佳屏蔽二进阵列偶的构造方法,即准最佳、双准最佳屏蔽阵列偶的复合构造法,利用最佳与准最佳屏蔽二进阵列偶来构造最佳屏蔽二进阵列偶,以及利用准最佳和双准最佳屏蔽二进阵列偶来构造准最佳屏蔽二进阵列偶。

关键词：信息论屏蔽二进阵列偶最佳信号相关信号