Title :
Numerical optimization for CDMA spreading sequences
Author :
El-Tarhuni, Mohamed G. ; Sheikh, Asrar U.
Author_Institution :
Dept. of Syst. & Comput. Eng., Carleton Univ., Ottawa, Ont., Canada
Abstract :
The performance of a direct sequence spread spectrum (DS-SS) code division multiple access (CDMA) communications systems is highly dependent upon the set of spreading sequences used in these systems. The multiple access interference could become very large if the spreading sequences are not carefully selected. A new numerical optimization procedure is proposed for the selection of spreading sequences based on minimizing the interference parameter among the sequences. The improvement in the average output signal-to-noise ratio or CDMA capacity improvement is used to compare the performance of the optimized code set with that of the set of Gold codes of the same length. An improvement of about 26% in the system capacity is obtained. Also, construction of different optimized code sets suitable for use in cellular systems applications is considered
Keywords :
cellular radio; code division multiple access; land mobile radio; mobile satellite communication; optimisation; pseudonoise codes; radiofrequency interference; spread spectrum communication; CDMA capacity improvement; CDMA spreading sequences; DS-SS; Gold codes; average output signal-to-noise ratio; cellular systems applications; code division multiple access; code length; communications systems; direct sequence spread spectrum; interference parameter; multiple access interference; numerical optimization; optimized code set; system performance; Autocorrelation; Bit error rate; Drives; Gold; High performance computing; Interference constraints; Multiaccess communication; Multiple access interference; Spread spectrum communication; Systems engineering and theory;
Conference_Titel :
Electrical and Computer Engineering, 1995. Canadian Conference on
Conference_Location :
Montreal, Que.
Print_ISBN :
0-7803-2766-7
DOI :
10.1109/CCECE.1995.528066
