Ricean信道下Turbo码性能研究

Performance for Turbo code on Ricean fading channel

针对Ricean衰落信道,在信道估计误差给定的情况下,提出一种新的Turbo码译码度量,推导出信道置信因子Lc新的表达形式。仿真结果表明,与采用传统近似译码度量相比,采用新的译码度量可以提高译码性能,信噪比改善0.1～0.6dB。而且在大主径衰落因子和小信道估计误差的情况下,译码性能优越,接近AWGN信道下Turbo码性能。

For a given channel estimation variance, a new metric for Turbo decoding on Ricean channel was proposed, and a novel formula for channel reliability factor Lc was concluded. The presented simulation results show that Turbo decoding with the proposed metric can obtain 0.1~0.6dB more code gain than that with the conventional metric. Furthermore, the performance with the modified metric excels under the condition of significant fading factor and small channel estimation variance, and approaches to the performance on the AWGN channel.