Abstract: Turbo code is generally selected as the forward error correction code for wireless communications due to its outstanding performance of approaching Shannon limit. However, the “error floor”limits the Bit Error Rate（BER） and Frame Error Rate（FER） performance of Turbo code. A novel Turbo decoding method, Residual Redundancy Turbo （RR?Turbo）is proposed for decreasing BER and FER by using residual redundancy information. The simulation results show that, compared with the traditional Turbo decoding methods, RR?Turbo can get 2?dB Signal Noise Ratio（SNR） gain, and reduce the “error floor” phenomenon.

Key words: Turbo code, residual redundancy, error floor, Bit Error Rate（BER）, Frame Error Rate（FER）

摘要： Turbo码有逼近香农极限的优异性能，特别适合用于无线通信链路上的前向纠错编码方案，但是标准Turbo码译码时存在错误平层（error floor）现象，误码率（BER）和误帧率（FER）有待进一步降低。提出了一种结合信源残留冗余信息进行译码的Turbo码（RR-Turbo码），通过为Turbo码的译码提供更充分的先验信息以进一步降低误码率和误帧率。仿真结果表明，RR-Turbo码比传统Turbo码在高信噪比区可得到2?dB的额外编码增益，有效改善了错误平层现象。

关键词: Turbo码, 残留冗余信息, 错误平层, 误码率, 误帧率