Paper Info
Title
Near-Capacity Detection and Decoding: Code Design for Dynamic User Loads in Gaussian Multiple Access Channels
Abstract
This paper considers the forward error correction (FEC) code design for approaching the capacity of a <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dynamic</italic> multiple access channel (MAC) where both the number of users and their respective signal powers keep constantly changing, resembling the scenario of an actual wireless cellular system. To obtain a low-complexity non-orthogonal multiple access (NOMA) scheme, we propose a serial concatenation of a low-density parity-check (LDPC) code and a repetition code (REP), this way achieving near Gaussian MAC (GMAC) capacity performance while coping with the dynamics of the MAC system. The joint optimization of the LDPC and REP codes is addressed by matching the analytical extrinsic information transfer (EXIT) functions of the sub-optimal multi-user detector (MUD) and the channel code for a specific and static MAC system, achieving near-GMAC capacity. We show that the near-capacity performance can be flexibly maintained with the same LDPC code regardless of the variations in the number of users and power levels. This flexibility (or elasticity) is provided by the REP code, acting as “user-load and power equalizer”, dramatically simplifying the practical implementation of NOMA schemes, as only a single LDPC code is needed to cope with the dynamics of the MAC system.
Year
DOI
Venue
2019
10.1109/TCOMM.2019.2935726
IEEE Transactions on Communications
Keywords
Field
DocType
Interleave division multiple access,EXIT chart,non-orthogonal multiple access,LDPC code,multi-user detection
Computer science,Communication channel,Electronic engineering,Gaussian,Decoding methods
Journal
Volume
Issue
ISSN
67
11
0090-6778
Citations 
PageRank 
References 
0
0.34
0
Authors
3
Name
Order
Citations
PageRank
Xiaojie Wang139566.31
sebastian cammerer215716.76
Stephan ten Brink32912204.86