tailieunhanh - Báo cáo hóa học: " LDGM Codes for Channel Coding and Joint Source-Channel Coding of Correlated Sources"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: LDGM Codes for Channel Coding and Joint Source-Channel Coding of Correlated Sources | EURASIP Journal on Applied Signal Processing 2005 6 942-953 2005 W. Zhong and J. Garcia-Frias LDGM Codes for Channel Coding and Joint Source-Channel Coding of Correlated Sources Wei Zhong Department of Electrical and Computer Engineering University of Delaware Newark DE 19716 USA Email zhong@ Javier Garcia-Frias Department of Electrical and Computer Engineering University of Delaware Newark DE 19716 USA Email jgarcia@ Received 2 October 2003 Revised 3 October 2004 We propose a coding scheme based on the use of systematic linear codes with low-density generator matrix LDGM codes for channel coding and joint source-channel coding of multiterminal correlated binary sources. In both cases the structures of the LDGM encoder and decoder are shown and a concatenated scheme aimed at reducing the error floor is proposed. Several decoding possibilities are investigated compared and evaluated. For different types of noisy channels and correlation models the resulting performance is very close to the theoretical limits. Keywords and phrases channel coding LDPC codes LDGM codes iterative decoding correlated sources joint source-channel coding. 1. INTRODUCTION The introduction of turbo codes 1 and low-density parity check LDPC codes 2 3 4 5 has been one of the most important milestones in channel coding during the last years. Provided that the information block lengths are long enough performance close to the Shannon theoretical limit can be achieved for different channel environments. However in practical applications complexity issues have to be carefully considered since both schemes present either high encoding or high decoding complexity. Specifically for the case of turbo codes the encoding complexity is very low but the decoding complexity is high. Compared with turbo codes standard LDPCs present a higher encoding complexity but the decoder is simpler. In this paper we first show that it is possible to achieve a channel coding performance .