一种用于LTE的提前终止Turbo码算法仿真

Performance Simulation of an Early Termination Turbo Code Algorithm for LTE

Turbo编码是Long Time Evolution(LTE)定义的信道编码形式,可以获得逼近香香农理论极限的译码性能,目前广泛应用于第3代和第4代移动通信系统中。为了解决Turbo译码时延长和计算复杂度的问题,研究了一种可以应用于LTE系统中的基于循环冗余校验的改进Turbo译码算法,在Turbo译码器中增加循环冗余校验(Cyclic Redundancy Check,CRC)提前终止准则,在译码迭代结束时检验是否存在错误比特码,在无CRC校验错误时提前终止迭代译码,在不影响译码性能的同时降低译码复杂度。Matlab仿真结果表明,与固定迭代次数的Turbo码算法相比,译码延迟得到了显著改善。

Turbo code is the channel coding standard of Long Time Evolution （LTE） ,which provides good performance close to Shannon limit.It is widely adopted by the 3rd and 4th Generation mobile communication systems.An improved Turbo decoding algorithm based on Cyclic Redundancy Check （CRC） is proposed to decrease the complexity and decoding latency. According to CRC early stopping decoding criteria, it checks whether there is error bit after each iteration decoding.Then the iteration can be terminated when there is no CRC error. Therefore the proposed algorithm would decrease the average decoder iteration without or with very little performance degradation.The Matlab experiment shows the significant reduction in decoding delay.