Performance of low-rate orthogonal convolutional codes in DS-CDMA applications

Author

Ormondroyd, R.F. ; Maxey, J.J.

Author_Institution

Sch. of Electron. & Electr. Eng., Bath Univ., UK

Volume

46

Issue

2

fYear

1997

fDate

5/1/1997 12:00:00 AM

Firstpage

320

Lastpage

328

Abstract

Low-rate orthogonal convolutional codes (LROCC), originally proposed by A.J. Viterbi (1971), can be used in a direct-sequence code-division multiple access (DS-CDMA) system to achieve both spreading of the data and providing coding gain. The implementation of this type of multiplexing in a practical DS-CDMA system is presented, and the theoretical performance of the proposed system under “other-user” noise, additive white Gaussian noise (AWGN), intercell interference, and thermal noise is established using a computer simulation. The improvement in system performance, gained through the use of a nonspreading randomizing sequence on the encoded output symbols, is also studied. Performance curves for a rate 1/64 orthogonal convolutional code are shown, and the impact of code rate, quantization methods, and constraint length on the overall system performance are discussed

Keywords

Gaussian noise; cellular radio; code division multiple access; convolutional codes; digital radio; land mobile radio; personal communication networks; pseudonoise codes; radiofrequency interference; spread spectrum communication; thermal noise; white noise; AWGN; DS-CDMA applications; additive white Gaussian noise; celluar radio; code rate; coding gain; computer simulation; constraint length; data spreading; digital personal communication network; direct sequence code division multiple access; encoded output symbols; intercell interference; low-rate orthogonal convolutional codes; multiplexing; nonspreading randomizing sequence; other-user noise; performance curves; quantization methods; rate 1/64 orthogonal convolutional code; system performance; thermal noise; AWGN; Additive white noise; Computer simulation; Convolutional codes; Direct-sequence code-division multiple access; Gaussian noise; Interference; Multiaccess communication; System performance; Viterbi algorithm;

fLanguage

English

Journal_Title

Vehicular Technology, IEEE Transactions on

Publisher

ieee

ISSN

0018-9545

Type

jour

DOI

10.1109/25.580770

Filename

580770