基于信道编码及空时编码级联的两用户协同分集

传统协同分集通过使网络中各单天线用户共享彼此天线,形成虚拟多天线阵列来实现空间分集,使得体积和功耗受限的网络终端也能获得分集增益,然而这并没有将信道编码和空时编码结合起来以使系统得到编码增益。为了能够获得编码增益来进一步改善系统性能,本文提出了一种基于信道编码和分布式空时分组码级联方式下的两用户协同分集方案,并且在准静态的瑞利衰落信道下对系统误码性能进行了理论推导和系统仿真,给出了误比特率的上限解析表达式。在协同用户间信道存在噪声的情况下,我们分别对CRC-DSTBC和CC-DSTBC级联下的发射方案进行了性能分析和系统仿真。仿真结果表明:即使协同用户间的信道存在噪声,本文所提出的协同分集方案与传统协同分集相比,不但获得了分集增益,同时也得到了编码增益,系统误比特率大大降低,从而显著提高了系统性能,并且这也和理论分析相吻合。

A Two-User Cooperative Diversity Scheme Based on Concatenated Channel Code and Space-Time Block Code

The traditional cooperative diversity,through sharing some single-antenna users'antennas of the network,form the vir- tual multi-antenna array to implement space diversity,and then cause that the limited bulk and power terminal of wireless network can al- so get diversity gain.However,these don't concatenate channel code and distributed space time code in order that the system get code gain.In order to obtain code gain and improve the system performance further,we present a two-user cooperative diversity scheme based on channel code and distributed space time code in this paper,and carry out the theoretical derivation and system simulation of code er- ror performance for the quasi-static rayleigh fading channels.A close form expression for bit error rate(BER)of the proposed scheme is derived without considering the decoding errors between interusers.With the interuser channel is noisy,we precede the analysis and sim- ulation for the CRC-DSTBC and CC-DSTBC scheme.Numerical results show that even though the interuser channel is noisy,the proposed cooperative diversity scheme,compared to traditional cooperative diversity,could get both diversity gain and code gain,with the bit error rate decreased greatly and system performance distinctly improved,and coincides with the theoretical results well.