Computer Engineering and Applications ›› 2007, Vol. 43 ›› Issue (4): 74-78.

• 产品、研发、测试 • Previous Articles     Next Articles

Sliding Window-Linear-Log-MAP Algorithm Used by UMTS Turbo Code and VLSI Design

刘小同 XiaoTong Liu   

  • Received:2006-07-07 Revised:1900-01-01 Online:2007-02-01 Published:2007-02-01
  • Contact: 刘小同 XiaoTong Liu

UMTS Turbo码的滑动窗-线性-Log-MAP算法及VLSI设计

刘小同 陈咏恩   

  1. 同济大学 上海同济大学电子信息工程学院
  • 通讯作者: 刘小同

Abstract: In this paper,we discuss the design of turbo code used by UMTS.Combining the sliding window method with forward state metric as an accuracy initialization value with a modified Log-MAP algorithm(Linear-Log-MAP),which is called Sliding Window-Linear-Log-MAP algorithm,we design the VLSI architecture for turbo decoder.Moreover,we present a method for normalizing the forward recursion that yields a 12.5% savings in memory usage.The FPGA result shows that our presented structure(SW-Linear-Log-MAP) results in only 0.2 dB away from the optimal structure(Log-MAP) at BER= .It has also a 30% hardware cost savings ,a small decoder delay and a high throughput.

摘要: 本文讨论UMTS中turbo码的设计,提出采用前向状态度量作为初始化精确值的滑动窗方法和改进的Log-MAP(线性Log-MAP)相结合的算法(称为滑动窗-线性-Log-MAP算法),设计出turbo码的VLSI结构,且在归一化处理时,介绍一种可节约12.5%存储量的方法。FPGA设计结果显示在BER= 时,与最优算法Log-MAP相比,性能损失0.2dB,硬件资源节约30%,译码时延小,吞吐量大。