Combined coding and spreading in CDMA systems using maximum free distance convolutional codes
Paper in proceeding, 1998

In CDMA systems maximum theoretical performance can be obtained by spreading with low-rate error control codes. Previously, orthogonal and superorthogonal codes have been proposed for this purpose. We present 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 superorthogonal codes as well as conventional coding/spreading schemes. We also show that our low-rate codes will give simple encoder and decoder implementation. With these codes any 1/n rate can be obtained regardless of the constraint length, resulting in a more flexible and powerful scheme than those proposed up to now.

maximum free distance

low-rate convolutional codes

orthogonal codes

superorthogonal codes

rate-compatible

CDMA

Author

Pål Frenger

Chalmers, Signals and Systems, Communication, Antennas and Optical Networks

Pål Orten

Chalmers, Signals and Systems, Communication, Antennas and Optical Networks

Tony Ottosson Gadd

Chalmers, Signals and Systems, Communication, Antennas and Optical Networks

Proceedings IEEE Vehicular Technology Conference, Ottawa, Canada

Vol. 3 2497-2501

Subject Categories

Computer and Information Science

DOI

10.1109/VETEC.1998.686209

More information

Created

10/6/2017