共查询到19条相似文献,搜索用时 203 毫秒
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基于Alamouti提出的BPSK调制下空时分组码在Rayleigh衰落信道中的简单分集方案。推导出多发射和多接收天线系统中正交空时分组码在Nakagami衰落信道的BPSK调制下的比特差错率的最小距离球界,并推广到在高阶调制下衰落信道中系统符号差错率的性能。仿真分析和比较了空时分组码的多天线系统中发射和接收天线分集增益,以及信道相关参数的变化对系统误比特性能的影响。 相似文献
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无线通信中的空时分组码及其性能分析 总被引:1,自引:0,他引:1
基于无线信道易受衰减和干扰影响的特点,介绍了用于瑞利衰落信道的空时分组码。给出了几种空时 分组码的编码和基于接收端线性处理的最大似然解码算法,建立了一个基站端和移动终端有若干个未线的系统模 型,分析其性能并进行仿真。仿真结果证明,通过空时分组码和多发射天线,可获得明显增益,且解码复杂度小。 相似文献
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瑞利快衰落信道下STBC的译码器设计 总被引:1,自引:0,他引:1
Alamouti提出的空时分组码(STBC)发射分集技术,其优良性能及低复杂性的译码方案是限制在准静态衰落信道的情况下的,通过研究发现此系统在时变快衰落信道时性能会有严重的损失。为了改善系统在快衰落信道下的性能,提出一种最小均方误差(MMSE)线性译码器,该译码器能够同时抑制噪声和干扰。理论及计算机仿真证明,MMSE译码器用于空时分组码发射分集系统中可以有效地改善无线信道的时变快衰落对系统性能的影响。 相似文献
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Du Yinggang Chan Kam Tai 《电子科学学刊(英文版)》2006,23(1):23-25
The Bit Error Rate (BER) performance of a Turbo Product Code (TPC) based Space-Time Block Coding (STBC) multiuser wireless system in the frequency-selective channels has been investigated. Both of the good error correcting capability of TPC and the large diversity gain of STBC can be achieved simultaneously. A Least Square Error-Recursive Least Square (LSE-RLS) algorithm is applied to estimate the channel and cancel the interference. Simulations show that the proposed system can obtain about 2.7dB gain in Es/N0 at the BER of 10^-3. 相似文献
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Hu Xianbin Gao Yuanyuan Yi Xiaoxin 《电子科学学刊(英文版)》2006,23(1):39-43
The closed-form solutions for error rates of Space-Time Block Code (STBC) Multiple Phase Shift Keying (MPSK) systems are derived in this paper. With characteristic function based method and the partial integration based respectively, the exact expressions of error rates are obtained for (2,1) STBC with and without channel estimation error. Simulations show that the practical error rates accord with the theoretical ones, so closed-form error rates are accurate references for STBC performance evaluation. For the error of pilot assisted channel estimation, the performance of a (2,1) STBC system is deteriorated about 3dB. 相似文献
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该文提出了MIMO CDMA系统中一种新的空时分组编译码方法,称为循环空时分组码(Cyclic Space-Time Block Code,C-STBC),它是将输入信息进行分组循环编码,然后对循环编码后的码字通过不同的天线分别采用不同的扩频码扩频后发射出去。这种CDMA系统下的循环空时分组码对任意的发射天线数都能达到满编码速率和满分集度,且其译码与传统的空时分组码一样简单。仿真结果验证了这种循环空时分组码优于传统的空时分组码。 相似文献
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该文提出了两种新的适用于时变信道下空时分组编码多用户系统的解码器设计方案。空时分组编码多用户系统下,传统的迫零(Zero Forcing, ZF)和最小均方误差(Minimum Mean Squared Error, MMSE)解码器设计均假定信道准静态衰落。信道时变时,这些传统解码器在解码某用户信号时引入符号间干扰(Inter-Symbol Interference, ISI),且这种干扰随信道时变增大而增加。基于此,该文设计了两种新的解码器,该解码器可显著降低信道时变的影响。仿真结果表明,随信噪比(Signal-to-Noise Ratio, SNR)增加,两种传统解码器均出现误码率性能平层,而新解码器获得了显著的性能改善。 相似文献
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Xu Feng Yue Dianwu 《电子科学学刊(英文版)》2007,24(4):462-469
Space time block coding is a modulation scheme recently discovered for the transmit an- tenna diversity to combat the effects of wireless fading channels. Using the equivalent Single-Input Single-Output (SISO) model, this paper presents closed-form expressions for the exact Symbol Error Rate (SER) and Bit Error Rate (BER) of Orthogonal Space-Time Block Codes (OSTBCs) with M-ary Phase-Shift Keying (MPSK) and M-ary Quadrature Amplitude Modulation (MQAM) over flat un- correlated Nakagami-m and Ricean fading channels. 相似文献
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该文对脉冲及非高斯噪声环境下空时分组码(STBC)性能进行了研究。采用脉冲和高斯加性混合噪声模型,利用矩母函数(MGF)分析方法,通过建立多发单收(MISO)近似等效模型,推导出Rayleigh衰落信道下MISO空时分组码误符号率(SER)闭式表达式的渐近解。在此基础上,对于不同脉冲噪声发生概率、脉冲噪声与高斯噪声功率比条件下STBC的性能进行了分析。结果表明,即使在高信噪比情况下,混合噪声也将会使STBC系统性能显著降低。蒙特卡洛仿真结果验证了SER闭式解的有效性。 相似文献
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Zhao Xianjing Zheng Baoyu 《电子科学学刊(英文版)》2007,24(6):740-747
A novel cooperative diversity scheme based on Distributed Space-Time Block Coding and Multi-Carrier Code Division Multiple Access (DSTBC-MC-CDMA) is proposed which works well in frequency selective fading channels with multiple single-antenna users. And an analytical error model is established to describe the symbol decoding errors between interusers, based on which a close form expression for theoretical Bit Error Rate (BER) performance of the scheme is derived to analyze the influence of the interuser decoding errors on the BER performance of the scheme. Then simulation is complimented to verify the analytic result above, which also shows that the BER performance of DSTBC-MC-CDMA outgoes that of non-cooperative MC-CDMA with considerable gains. Further- more, the simulations coincide with the theoretical results well. 相似文献