多模Turbo编解码器的正交交织器设计

Design of Interlearvers for Multi-Modes Turbo En-Decoders

采用多模Turbo编解码器可复用CDMA信道,显著增加CDMA系统用户容量.提出一种用于多模Turbo编解码器的交织器设计方法.以往有关Turbo码交织器的讨论多着眼于设计一个最佳交织器,最大限度降低校验比特间的相关性,从而降低误比特率,而本文从不同交织器间的相关性出发,基于素数序列,分别构造出一组具有最佳汉明正交特性和准最佳汉明正交特性的交织器族,适用于同步系统和异步系统内的多模Turbo编解码器.理论分析和仿真结果表明该方法是正确有效的.

With multi-modes Turbo en-decoders for channel multiplexing, the user capacity of CDMA system could increase remarkably. In this paper, we present a design of interleavers for multi-modes Turbo en-decoders. Different from the presented work, where an optimal interleaver is considered mostly for reducing the correlation between parity bits of different paths and bit error rate(BER) of iterative decoding, the method based on prime sequences is demonstrated in this paper to obtain a family of interleavers index sequences with optimal Hamming correlation or quasi-optimal Hamming correlation characteristic respectively. With these sequences, two families of interleavers for multi-modes Turbo en-decoders in synchronous systems and asynchronous systems are constructed respectively. Theoretical deduction and simulations verified that the approach is reasonable and effective.