摘要
分析了分组相关快衰落信道的特性,推导出该信道下Turbo码译码算法;研究了迭代次数对Turbo编码系统的影响,在小信噪比弥散度条件下,提出基于平均信噪比的最佳迭代译码次数自适应选择方案,可以兼顾译码性能和译码速度,得到较低的平均误比特率和较高的平均译码速度。仿真结果说明,本文提出的Turbo码译码算法,降低了对信道估计精度要求的同时,得到精确信道估计时的性能;对于目标误比特率为10-4时,采用自适应Turbo译码算法,与固定迭代4次相比,平均误比特率降低了40%,提高了系统性能;而与固定迭代8次相比,迭代次数降低了约1/4,提高了译码速度。
With the knowledge of correlated block fast fading channel, a new Turbo decoding algorithm is proposed. And studying the effect of the iterations on the turbo-coded system, we propose a new scheme based on adaptive selection of iterations for decoding under the condition of little SNR variance. Considering both performance and speed of the decoding, the proposed scheme is proved to decrease the mean BER and accelerate the decoding. The simulation results show that the proposed decoding algorithm can reduce the complexity of the channel estimation without the loss of performance. Also, given the target BER of 10-4, the adaptive scheme can bring out the increase of mean BER by 40% versus 4-iteration decoding and the decrease of iterations by 25% versus 8-iteration decoding.
出处
《微电子学与计算机》
CSCD
北大核心
2005年第6期94-97,共4页
Microelectronics & Computer
基金
国防973项目(51308)
