摘要： 研究了分组相关快衰落信道的特性，推导出该信道下Turbo 码的译码算法，并从推导结果确定：平均信噪比和信噪比弥散度是影响系统性能的两个重要参数。仿真结果表明，在分组相关快衰落信道下，采用该文提出的Turbo 码译码算法，可以提高整个系统性能，在误比特率为10-3 时，与信道编码采用卷积码的系统相比，信噪比改善2.9dB；在大平均信噪比和小信噪比弥散度条件下，系统性能较好，误比特率较低。

关键词: Turbo 码；分组相关快衰落信道；平均信噪比；信噪比弥散度

Abstract: With the knowledge of correlated block fast fading channel, a new Turbo decoding algorithm is proposed. And from the algorithm, it is concluded that the mean and variance of signal-to-noise ratio are important to the performance. The simulation results show that the proposed algorithm can bring out about 2.9dB code gain over the scheme which adopts convolution code. Also the performance with the proposed algorithm is very good under the condition of significant mean and small variance of the signal-to-noise ratio.

Key words: Turbo code; Correlated block fast fading channel; Mean of the signal-to-noise ratio; Variance of signal-to-noise ratio