Title :
Comparison of the performance of some linear spreading code families for asynchronous DS/SSMA systems
Author :
Kärkkäinen, Kari H. ; Leppãnen, Pentti A.
Author_Institution :
Dept. of Electr. Eng., Oulu Univ., Finland
Abstract :
The performance of an asynchronous biphase coded direct sequence spread-spectrum multiple-access (DS/SSMA) system is studied, when maximum length, Gold, and a small set of Kasami sequences are used as spreading codes. The signal-to-noise ratio (SNR) at the output of an asynchronous DS/SSMA receiver and the average interference parameter were used as performance measures. It was found that use of the AO/LSE and LSE/AO phase optimization criteria did not give any significant advantage in decibels as compared to randomly selected sequence phases, as the criteria do not minimize cross-correlation functions directly. There are no appreciable differences in SNR performance between sets of Gold, Kasami, and M-sequences. The SNR performance curves of sets of Gold, Kasami, and M-sequences of sufficiently long periods were found to be very close to those of sufficiently random, independent binary spreading sequences of equal length
Keywords :
code division multiple access; encoding; optimisation; radio receivers; spread spectrum communication; AO/LSE; CDMA; DS/SSMA; Gold sequences; Kasami sequences; LSE/AO; M-sequences; SNR; asynchronous biphase coded direct sequence spread-spectrum multiple-access; asynchronous receiver; average interference parameter; code division multiple access; cross-correlation functions; maximum length; maximum length sequences; performance measures; phase optimization criteria; signal-to-noise ratio; spreading codes; Cellular phones; Frequency division multiaccess; Gold; Laboratories; Multiaccess communication; Multiple access interference; Personal communication networks; Signal to noise ratio; Spread spectrum communication; Time division multiple access;
Conference_Titel :
Military Communications Conference, 1991. MILCOM '91, Conference Record, Military Communications in a Changing World., IEEE
Conference_Location :
McLean, VA
Print_ISBN :
0-87942-691-8
DOI :
10.1109/MILCOM.1991.258369