Title
Precoding and Symbol Grouping for NAF Relaying in BICM Systems
Abstract
This paper considers the precoder design for a bandwidth-efficient bit-interleaved coded modulation (BICM) system over nonorthogonal amplify-and-forward (NAF) single-relay channels with an arbitrary length of cooperative frame 2N. Based on the tight union bound to the bit error probability (BEP), we first derive an asymptotic design criterion with regard to a general 2N × 2N rotation matrix. This expression allows us to develop a class of precoders that not only achieves full cooperative diversity but optimizes the asymptotic error performance as well. Interestingly, the developed class of optimal precoders indicates that the source should keep silent in the cooperative phase. In the broadcasting phase, it is shown that power is equally distributed to 2N information symbols at the source. By further examining the structure of the optimal class of 2N × 2N precoders, it is then revealed that precoding over a group of at least two information symbols is sufficient to fully exploit diversity and coding advantages. Such a precoding technique, which is referred to as symbol grouping, therefore significantly reduces the system complexity without sacrificing the error performance. Among the pool of optimal precoders with respect to the asymptotic performance, the design of a precoder that provides a good convergence property is also discussed. Numerical examples show that the proposed precoder greatly improves the error performance of the cooperative system with low complexity.
Year
DOI
Venue
2013
10.1109/TVT.2013.2245927
Vehicular Technology, IEEE Transactions
Keywords
Field
DocType
amplify and forward communication,codecs,cooperative communication,diversity reception,precoding,telecommunication channels,2N information symbols,BEP,BICM systems,NAF relaying,arbitrary length,asymptotic design criterion,asymptotic error performance,asymptotic performance,bandwidth-efficient bit-interleaved coded modulation system,cooperative frame 2N,cooperative phase,cooperative system,diversity,error performance,nonorthogonal amplify-and-forward single-relay channels,optimal precoders,precoder design,precoding technique,rotation matrix,symbol grouping,Amplify-and-forward (AF),bandwidth efficient,bit-interleaved coded modulation (BICM),precoder,relay channel,symbol grouping
Convergence (routing),Broadcasting,Rotation matrix,Computer science,Cooperative diversity,Communication channel,Electronic engineering,Coding (social sciences),Codec,Precoding
Journal
Volume
Issue
ISSN
62
6
0018-9545
Citations 
PageRank 
References 
1
0.35
16
Authors
4
Name
Order
Citations
PageRank
Nghi H. Tran1572.74
Leonardo Jiménez Rodríguez281.19
Tho Le-Ngoc32210237.14
Hamid-Reza Bahrami4748.75