Why design spreading codes for multiuser CDMA channels?

Phil Whiting; Alex J. Grant; Paul D. Alexander

doi:10.1109/PIMRC.1995.477379

Why design spreading codes for multiuser CDMA channels?

Phil Whiting^*, Alex J. Grant, Paul D. Alexander

^*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceeding › Conference proceeding contribution › peer-review

2 Citations (Scopus)

Abstract

We examine the behavior of the information theoretic capacity of jointly detected (multiuser) symbol synchronous DS-SSMA systems, when randomly selected spreading sequences are used. We find upper and lower bounds on capacity for a certain cross-correlation measure, and show that if the number of users is larger than the sequence length, that the lower bound tends to the maximum capacity with increasing sequence length. This implies that for large systems, random spreading sequences are optimal in terms of capacity. We also examine more realistic cases for the number of users and sequence length, and find that in certain cases that the use of random spreading sequences results only in a very small decrease in capacity.

Original language	English
Title of host publication	IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC
Place of Publication	Piscataway, N.J.
Pages	1331-1334
Number of pages	4
Volume	3
DOIs	https://doi.org/10.1109/PIMRC.1995.477379
Publication status	Published - Sept 1995
Externally published	Yes
Event	Proceedings of the 1995 6th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC'95. Part 3 (of 3) - Toronto, Can Duration: 27 Sept 1995 → 29 Sept 1995

Other

Other	Proceedings of the 1995 6th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC'95. Part 3 (of 3)
City	Toronto, Can
Period	27/09/95 → 29/09/95

Access to Document

10.1109/PIMRC.1995.477379

Cite this

@inproceedings{a78416339e144ebda1e3d2537594e20e,

title = "Why design spreading codes for multiuser CDMA channels?",

abstract = "We examine the behavior of the information theoretic capacity of jointly detected (multiuser) symbol synchronous DS-SSMA systems, when randomly selected spreading sequences are used. We find upper and lower bounds on capacity for a certain cross-correlation measure, and show that if the number of users is larger than the sequence length, that the lower bound tends to the maximum capacity with increasing sequence length. This implies that for large systems, random spreading sequences are optimal in terms of capacity. We also examine more realistic cases for the number of users and sequence length, and find that in certain cases that the use of random spreading sequences results only in a very small decrease in capacity.",

author = "Phil Whiting and Grant, {Alex J.} and Alexander, {Paul D.}",

year = "1995",

month = sep,

doi = "10.1109/PIMRC.1995.477379",

language = "English",

isbn = "0780330021",

volume = "3",

pages = "1331--1334",

booktitle = "IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC",

note = "Proceedings of the 1995 6th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC'95. Part 3 (of 3) ; Conference date: 27-09-1995 Through 29-09-1995",

}

Whiting, P, Grant, AJ & Alexander, PD 1995, Why design spreading codes for multiuser CDMA channels? in IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC. vol. 3, 477379, Piscataway, N.J., pp. 1331-1334, Proceedings of the 1995 6th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC'95. Part 3 (of 3), Toronto, Can, 27/09/95. https://doi.org/10.1109/PIMRC.1995.477379