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Spectral Efficiency of Random Time-Hopping CDMA.

Authors :
Ferrante, Guido Carlo
Benedetto, Maria-Gabriella Di
Source :
IEEE Transactions on Information Theory; Dec2015, Vol. 61 Issue 12, p6643-6662, 20p
Publication Year :
2015

Abstract

Traditionally paired with impulsive communications, time-hopping code-division multiple access (TH-CDMA) is a multiple access technique that separates users in time by coding their transmissions into pulses occupying a subset of N_ \mathsf s chips out of the total N included in a symbol period, in contrast with the traditional direct-sequence CDMA (DS-CDMA), where N_ \mathsf {s}=N . This paper analyzes the TH-CDMA with random spreading, by determining whether peculiar theoretical limits are identifiable, with both optimal and suboptimal receiver structures, in particular in the archetypal case of sparse spreading, that is, N_ \mathsf {s}=1$ . Results indicate that the TH-CDMA has a fundamentally different behavior than DS-CDMA, where the crucial role played by energy concentration, typical of TH, directly relates with its intrinsic uneven use of degrees of freedom. [ABSTRACT FROM PUBLISHER]

Details

Language :
English
ISSN :
00189448
Volume :
61
Issue :
12
Database :
Complementary Index
Journal :
IEEE Transactions on Information Theory
Publication Type :
Academic Journal
Accession number :
111152674
Full Text :
https://doi.org/10.1109/TIT.2015.2490218