Joint variable threshold M-QAM and ARQ for Nakagami-m fading channel with feedback delay

Author

Lee, Sang-Do ; Ko, Young-Chai

Author_Institution

Samsung Electron., Suwon, South Korea

Volume

14

Issue

2

fYear

2010

fDate

2/1/2010 12:00:00 AM

Firstpage

139

Lastpage

141

Abstract

In this paper, we develop a cross-layer combining of adaptive M-ary quadrature amplitude modulation (M-QAM) and automatic repeat request (ARQ) protocol, which adapts the threshold of rate-region boundaries to the variation of feedback delay over the Nakagami-m fading (NMF) channels. We derive a threshold adaptation scheme to reduce the effect of the feedback delay on bit error rate (BER). Numerical results reveal that MQAM with threshold adaptation is more reliable to the feedback delay than M-QAM with fixed thresholds. When we combine the proposed scheme with ARQ, the enhanced BER can lower the probability of packet loss and reduce the number of packet retransmissions.

Keywords

Nakagami channels; automatic repeat request; error statistics; quadrature amplitude modulation; -ary quadrature amplitude modulation; ARQ; BER; Nakagami-m fading channel; automatic repeat request protocol; bit error rate; feedback delay; joint variable threshold M-QAM; Automatic repeat request; Bit error rate; Communication system control; Delay effects; Fading; Feedback; Physical layer; Receiving antennas; Signal to noise ratio; Transmitters; Threshold adaptation, feedback delay, M-QAM and ARQ;

fLanguage

English

Journal_Title

Communications Letters, IEEE

Publisher

ieee

ISSN

1089-7798

Type

jour

DOI

10.1109/LCOMM.2010.02.092191

Filename

5403613