Code-spread CDMA using low-rate convolutional codes
Paper in proceedings, 1998

In code division multiple-access (CDMA) systems, maximum total throughput assuming a matched filter receiver can be obtained by spreading with low-rate error control codes. Previously, orthogonal, bi-orthogonal and super-orthogonal codes have been proposed for this purpose. We present in this paper a family of rate-compatible low-rate convolutional codes with maximum free distance. The performance of these codes for spectrum spreading in a CDMA system is evaluated and shown to outperform that of orthogonal and super-orthogonal codes as well as conventionally coded and spread systems. We also show that the proposed low rate codes will give simple encoder and decoder implementations. With these codes, any rate 1/n, n⩽512, are obtained for constraint lengths up to 11, resulting in a more flexible and powerful scheme than those previously proposed.

Author

Pål Frenger

Chalmers, Signals and Systems, Communication and Antenna Systems, Communication Systems

Pål Orten

Chalmers, Signals and Systems, Communication and Antenna Systems, Communication Systems

Tony Ottosson Gadd

Chalmers, Signals and Systems, Communication and Antenna Systems, Communication Systems

Proceedings IEEE International Symposium on Spread Spectrum Techniques and Applications, Sun City, South Africa

Vol. 48 1 374-378

Subject Categories

Computer and Information Science

DOI

10.1109/26.818881

More information

Created

10/7/2017