A new spreading scheme for convolutionally coded CDMA communication in a Rayleigh-fading channel

Author

Bang, Young Jo ; Kim, Sang Wu

Author_Institution

Dept. of Electr. Eng., Korea Adv. Inst. of Sci. & Technol., Taejon, South Korea

Volume

44

Issue

11

fYear

1996

fDate

11/1/1996 12:00:00 AM

Firstpage

1537

Lastpage

1542

Abstract

There has been increased interest in the use of direct-sequence code-division multiple-access (DS/CDMA) for wireless communication systems. We find that the asymptotic bit-error probability (BEP), P_b, of a convolutionally coded code-division multiple-access (CDMA) system in a frequency-selective Rayleigh-fading channel depends on the length of the shortest error event path and the product of symbol distances along that path. Based on this observation, we propose a new spreading scheme that maximizes the length of the shortest error event path. It is shown that the proposed scheme yields an improvement of 1.0-1.3 dB at P_b=10^-5 over the conventional convolutionally coded CDMA system, and even a higher improvement can be achieved as the required BEP is decreased

Keywords

Rayleigh channels; code division multiple access; coding errors; convolutional codes; error statistics; fading; pseudonoise codes; spread spectrum communication; BEP; DS/CDMA; Rayleigh fading channel; asymptotic bit error probability; convolutionally coded CDMA communication; direct-sequence code-division multiple-access; frequency selective fading channel; performance analysis; shortest error event path; spreading scheme; symbol distances; wireless communication systems; AWGN channels; Additive white noise; Convolution; Convolutional codes; Fading; Frequency; Interleaved codes; Multiaccess communication; Rayleigh channels; Transmitters;

fLanguage

English

Journal_Title

Communications, IEEE Transactions on

Publisher

ieee

ISSN

0090-6778

Type

jour

DOI

10.1109/26.544470

Filename

544470