LDPC-coded cooperative relay systems: performance analysis and code design

We treat the problem of designing low-density parity-check (LDPC) codes to approach the capacity of relay channels. We consider an efficient analysis framework that decouples the factor graph (FG) of a B -block transmission into successive partial FGs, each of which denotes a two-block transmission....

Full description

Saved in:
Bibliographic Details
Published in:IEEE transactions on communications 2008-03, Vol.56 (3), p.485-496
Main Authors: Chuxiang Li, Guosen Yue, Khojastepour, M.A., Xiaodong Wang, Madihian, M.
Format: Article
Language:English
Subjects:
Applied sciences
Approximation
AWGN channels
Binary system
Channel capacity
Channels
Codes
Coding, codes
Design engineering
Design methodology
Detection, estimation, filtering, equalization, prediction
Detectors
Evolution
Exact sciences and technology
Gaussian approximation
Information analysis
Information, signal and communications theory
Mathematical models
MIMO
Optimization
Parity check codes
Performance analysis
Relay
Relay systems
Relays
Signal and communications theory
Signal, noise
Systems, networks and services of telecommunications
Telecommunications
Telecommunications and information theory
Transmission and modulation (techniques and equipments)
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We treat the problem of designing low-density parity-check (LDPC) codes to approach the capacity of relay channels. We consider an efficient analysis framework that decouples the factor graph (FG) of a B -block transmission into successive partial FGs, each of which denotes a two-block transmission. We develop design methods to find the optimum code ensemble for the partial FG. In particular, we formulate the relay operations and the destination operations as equivalent virtual MISO and MIMO systems, and employ a binary symmetric channel (BSC) model for the relay node output. For AWGN channels, we further develop a Gaussian approximation for the detector output at the destination node. Jointly treating the relay and the destination, we analyze the performance of the LDPC-coded relay system using the extrinsic mutual information transfer(EXIT) chart technique. Furthermore, differential evolution is employed to search for the optimum code ensemble. Our results show that the optimized codes always outperform the regular LDPC codes with a significant gain; in the AWGN case, when Protocol-II is employed and the relay is close to the source, the optimized code performs within 0.1dB to the capacity bound.
ISSN:0090-6778
1558-0857
DOI:10.1109/TCOMM.2008.060032