Title :
Log likelihood ratios for convolutionally encoded parity bit selected DS-SS system
Author :
Mirzaee, Alireza ; Amours, Claude D.
Author_Institution :
Sch. of Inf. Technol. & Eng., Ottawa Univ., Ottawa, ON
Abstract :
In this paper we investigate the performance of the parity bit selected direct sequence spread spectrum (DS-SS) system using log likelihood ratio (LLR). In this system information bits are convolutionally encoded prior to being used in the parity bit selected DS-SS system. Reliability of the detected bits in the receiver is calculated in the form of LLRs and then used as the input of a soft input Viterbi decoder. The performance of the proposed system is compared to conventional coded spread spectrum systems where no parity bit selected spreading sequence is used.
Keywords :
code division multiple access; convolutional codes; pseudonoise codes; spread spectrum communication; DS-SS system; convolutionally encoded parity bit; detected bits reliability; direct sequence spread spectrum system; log likelihood ratios; soft input Viterbi decoder; Bit error rate; Block codes; Convolution; Convolutional codes; Decoding; Information technology; Matched filters; Spread spectrum communication; Transmitters; Vectors; Spread spectrum communication; error control coding; log likelihood ratio;
Conference_Titel :
Electrical and Computer Engineering, 2008. CCECE 2008. Canadian Conference on
Conference_Location :
Niagara Falls, ON
Print_ISBN :
978-1-4244-1642-4
Electronic_ISBN :
0840-7789
DOI :
10.1109/CCECE.2008.4564739
