The effects of constellation density on trellis-coded modulation in fading channels

Author

Ho, Paul K. ; Cavers, James K. ; Varaldi, Jean L.

Author_Institution

School of Eng. Sci., Simon Fraser Univ., Burnaby, BC, Canada

Volume

42

Issue

3

fYear

1993

fDate

8/1/1993 12:00:00 AM

Firstpage

318

Lastpage

325

Abstract

Dense constellations such as 16-QAM (quadrature amplitude modulation) have not seen much use in mobile communication because of their greater peak-to-average power ratio and their seemingly greater sensitivity to noise and channel interference. It is demonstrated that dense constellations can actually improve performance. Using a completely analytical method, three constellations are compared with the same net throughput of 2 bits/symbol: uncoded QPSK (quadrature phase-shift keying), rate 2/3 TCM (trellis-coded modulation) 8-PSK and rate 1/2 TCM 16-QAM. Comparison on the basis of average power puts TCM 16-QAM 5-dB ahead of TCM 8-PSK (phase-shift keying). Even comparison on the basis of peak power gives TCM 16-QAM a 2.44-dB advantage over TCM 8-PSK. QPSK is much poorer than either

Keywords

amplitude modulation; digital radio systems; fading; mobile radio systems; phase shift keying; telecommunication channels; trellis codes; TCM 16-QAM; TCM 8-PSK; channel interference; constellation density; digital radio systems; fading channels; mobile communication; noise; peak-to-average power ratio; quadrature amplitude modulation; quadrature phase-shift keying; rate 1/2 TCM; rate 2/3 TCM; trellis-coded modulation; uncoded QPSK; Interference; Mobile communication; Noise level; Peak to average power ratio; Phase modulation; Phase shift keying; Quadrature amplitude modulation; Quadrature phase shift keying; Signal to noise ratio; Throughput;

fLanguage

English

Journal_Title

Vehicular Technology, IEEE Transactions on

Publisher

ieee

ISSN

0018-9545

Type

jour

DOI

10.1109/25.231884

Filename

231884