使用事先資訊之三元渦輪編碼調變

Abstract

因為渦輪碼擁有非常好的錯誤更正能力，所以在近10年它已經成為無線通訊中相當重要的一種改錯碼技術。然而一個好的渦輪碼通常需要很長的交錯器，長的交錯器雖然能夠提升渦輪碼的性能但也造成冗長的解碼延遲以及需要大量的儲存記憶體。此外，因為渦輪碼有error floor的現象導致在高的SNR時它無法達到很低的錯誤率。

在這篇論文中我們提出了一種使用事先資訊之三元渦輪編碼調變系統，簡稱為鑲入已知資訊之三元渦輪編碼調變。相較於使用交錯器長度20730的一般渦輪碼，使用交錯器長度800的鑲入已知資訊之三元渦輪編碼調變不但可以節省86%的記憶體並且降低94%的解碼延遲。另外在錯誤率10-5和10-6之下，此系統比一般渦輪編碼器還要好0.2dB 和0.6dB。

Recently, (binary) turbo code is one of most important coding techniques for wireless communication due to its excellent error correction ability. The main problem of turbo code is that using a long interleaver is able to support its remarkable performance, but a long decoding latency and huge memory size are introduced. Moreover, at high SNR, the error floor phenomenon causes that turbo code unable to achieve very low bit error rates.

In this thesis the ternary turbo coded modulation using embedded prior information, in short, called EPI TTC is presented. Comparison with binary turbo code with interleaver size of 20730, the proposed system with interleaver size of 800 can save not only memory size about 86% but also decoding latency about 94%. In addition, it has 0.2 dB and 0.6 dB performance gains than binary turbo code at BER of 10-5 and 10-6, separately.