分布式RS码的协作及基于权重分配的联合译码研究

Research on Collaboration of Distributed RS Codes and Joint Decoding Based on Weight Assignment

通信系统面临的主要挑战之一是减轻无线信道衰落的影响,衰落会引起接收信号功率的波动,降低系统性能。减少衰落影响的一种常用方法是使用分集技术,这些技术通过多个独立的信道传输预期信号,减轻了衰落的影响。为了研究RS码在分集技术下的性能表现,设计了分布式RS码的中继协作系统,并采用基于权重分配的译码算法。目的节点接收到来自源节点和中继节点的两路幅值信号后,将两路信号的实部与虚部乘以权重,并将实部与虚部独立进行相加之后的结果进行QAM硬判决,之后使用Berlekamp迭代译码算法进行译码。设计比较RS(63,51)码与RS(255,239)码在加性高斯白噪声信道(Additive White Gaussian Noise,AWGN)和快衰落信道(Fast fading channel)下性能表现。对于RS(63,51)码的权重协作方案,在快衰落信道下,误码率为10-6时,相比于非协作方案,大约有5 dBs的性能增益,带来显著的分集增益。

One of the main challenges faced by communication systems is to mitigate the effects of wireless channel fading,which may cause fluctuations in received signal power and degrade system performance.One common approach to reduce the effects of fading is to use diversity techniques that transmit expected signals over multiple independent channels to mitigate the effects of fading.In order to study the performance of RS(Reed Solomon)code under diversity technology,a relay cooperative system based on distributed RS code is designed,and a decoding algorithm based on weight assignment is adopted.After receiving the two amplitude signals from the source node and the relay node,the destination node multiplies the real part and the imaginary part of the two signals by the weight,and decides the result of adding the real part and the imaginary part independently by QAM hard decision,then uses the Berlekamp iterative decoding algorithm for decoding.The performances of RS(63,51)code and RS(255,239)in Additive White Gaussian Noise(AWGN)and fast fading channel are compared.For the weight cooperation scheme of RS(63,51),under the fast fading channel,when the bit error rate is 10-6,there is about 5 dBs performance gain as compared with the non-cooperative scheme.The diversity gain brought by this scheme is significant.