NEW ITERATIVE SUPER-TRELLIS DECODING WITH SOURCE A PRIORI INFORMATION FOR VLCS WITH TURBO CODES

A novel Joint Source and Channel Decoding (JSCD) scheme for Variable Length Codes (VLCs) concatenated with turbo codes utilizing a new super-trellis decoding algorithm is presented in this letter. The basic idea of our decoding algorithm is that source a priori information with the form of bit transition probabilities corresponding to the VLC tree can be derived directly from sub-state transitions in new composite-state represented super-trellis. A Maximum Likelihood (ML) decoding algorithm for VLC sequence estimations based on the proposed super-trellis is also described. Simu-lation results show that the new iterative decoding scheme can obtain obvious encoding gain especially for Reversible Variable Length Codes (RVLCs),when compared with the classical separated turbo decoding and the previous joint decoding not considering source statistical characteristics.

TD-SCDMA系统中TFCI译码算法的改进

在3GPP的物理层协议中传输格式组合指示TFCI采用了类Reed—Muller编码,但标准中没有说明其译码算法。文中将介绍由快速哈达码变换与超码译码结合实现的译码算法,为了提高算法的效率和降低误码率,提出基于tfcNum的快速哈达码变换与超码译码结合实现的译码算法,通过仿真看到改进后译码的效率提高,误码率降低,对整个TD-SCDMA系统有很大的实用价值。

TD-SCDMA系统中基于最大TFCS的TFCI译码算法

作为3G标准之一的TD-SCDMA系统,它的物理层协议对传输格式组合指示TFCI采用了双正交编码方法,但是标准中没有规定具体的译码算法。文中提出了一种在其编码方法的基础上简单高效的译码算法——基于最大TFCS的TFCI译码算法。其效率高,误码率低,性能较一阶Reed_Muller译码和快速哈达码变换译码有很大提升。