Turbo-空时分组码系统信道编译码方法

Channel encoding and decoding method for Turbo-space time block codes system

为抵抗无线通信信道的选择性衰落以及提高系统的通信质量,提出了一种多发射天线多接收天线系统的信道编译码方法.Turbo-空时分组码系统的译码算法综合了2种码字的译码算法.采用多发射天线的系统结合空时分组码(STBC)码字矩阵和无线通信信道特性,推导了Turbo码译码过程所需的对数似然比(LLR);采用多接收天线的系统将各天线计算所得的对数似然比最大比合并(MRC)再进行迭代译码.仿真结果表明,Turbo-空时分组码系统能够综合Turbo码的编码增益和空时分组码的分集增益,编译码复杂度不高,性能优异;在同等条件下,此译码算法所需信噪比优于基于最小欧式距离的译码算法近0.5 dB.

A channel encoding and decoding method was proposed for multiple transmit antennas and multiple receive antennas system to combat the selective fading existing in wireless communication channel and improve communication quality. The decoding arithmetics of Turbo codes and space time block codes were combined appropriately in the Turbo-space time block codes system. The codeword matrix of space time block codes and the channel property were used to deduce the logarithm likelihood ratio （LLR） used in the decoding process of Turbo codes in multiple transmit antennas system. The logarithm likelihood ratio computed for each receive antennas was maximal ratio combined （MRC） and then iterative decoded in multiple receive antennas system. Simulation show that the Turbo-space time block codes system benefits from the coding gain of Turbo codes and the diversity gain of space time block codes and has low complexity and excellent performance. The SNR of proposed arithmetic is superior the minimum Euclidean distance arithmetic by 0.5 dB.