【摘要】 针对瑞利信道中存在的严重的多径衰落 ,本文实现了Turbo -TCM方案与时空分组码的级联系统 ,以期利用空间分集改善系统的误码率性能。针对级联系统的译码 ,本文给出了一种具有低译码时延的次优译码算法 ,该算法的特点是各模块独立译码 ,先算比特对数似然比再进行二进制Turbo码译码。最后通过计算机仿真给出了使用该次优译码算法的Turbo -TCM方案与时空分组码的级联系统的译码性能。仿真结果说明 ,当发射天线数目一定时 ,随着接收天线数目的增加 ,译码性能的增益随之增加而帧长对译码性能的影响则随之减小。更多还原

【Abstract】 To resist severe multi-path fading over Rayleigh channel, this paper achieves wireless communication system concatenated with Turbo-TCM and space time block codes. We hope the concatenated system can improve decoding performance by utilizing additional spatial diversity. This paper presents a sub-optimum decoding algorithm with low decoding delay for the concatenated system. The algorithm decodes modules of the concatenated system separately. During the process of decoding, the log-likelihood of coded bits are calculated firstly, then these log-likelihood values are sent into binary Turbo decoder to make hard decision. The decoding performance of concatenated systems is simulated through computer. According to simulations, when the number of transmit antenna is constant, the coding gain increases but the influence on decoding performance produced by the length of information frame decreases with the increment of the number of receive antenna.更多还原