EXIT Analysis of Interleaver Division Multiple Access System with LDPC Code

Abstract

Abstract Extrinsic Information Transfer(EXIT) characteristics are extensively used in iterative detection and decoding of turbo type processing. This paper makes an exploratory study of the issue of EXIT characteristic analysis for Low-Density Parity Check (LDPC) coded Interleaver Division Multiple Access (IDMA) system in Multiple Access Channel(MAC) condition. By using simulation method and extrinsic information calculation, the a priori information of the IDMA detector and the extrinsic information can be gained. In the same way, the a priori information and extrinsic information of the LDPC decoder in the system can be procured. The EXIT characteristic of the detector illustrates the convergence the detection algorithm of IDMA, while the EXIT characteristic of the LDPC decoder illustrates the convergence nature of the optimized degree profile,which shows the reasonability of LDPC coded IDMA system and the reliability of the optimized degree optimized algorithm for multiple access channel.