Title :
A study of band-limited chip waveforms for asynchronous DS-CDMA systems
Author_Institution :
Dept. of Electr. Eng., Saskatchewan Univ., Saskatoon, Sask., Canada
Abstract :
This paper investigates the effect of chip waveform shaping on multiple access interference (MAI) in band-limited direct sequence code-division multiple access (DS-CDAM) systems. In particular, it concentrates on the family of band-limited waveforms with zero interchip interference (ICI) and with arbitrary excess bandwidth β in the range 0 ≤ β ≤ 1. A criterion for the performance comparison of various band-limited chip waveforms based on the elementary density function is introduced. The comparison is made among different chip waveforms, including the optimal chip waveform, the square-root raised cosine proposed for 3G wireless systems and the previously proposed "better than Nyquist" pulse. Finally, the effect of varying the roll-off factor of a band-limited chip waveform on the MAI level is also investigated.
Keywords :
bandlimited communication; cellular radio; code division multiple access; multiuser channels; radiofrequency interference; spread spectrum communication; 3G wireless systems; asynchronous DS-CDMA systems; band-limited chip waveforms; better than Nyquist pulse; chip waveform shaping; direct sequence code-division multiple access; elementary density function; multiple access interference; optimal chip waveform; performance comparison; roll-off factor; square-root raised cosine; Bandwidth; Direct-sequence code-division multiple access; Interference constraints; Multiaccess communication; Multiple access interference; Multiuser detection; Performance analysis; Pulse shaping methods; Random variables; Spectral shape;
Conference_Titel :
Electrical and Computer Engineering, 2002. IEEE CCECE 2002. Canadian Conference on
Print_ISBN :
0-7803-7514-9
DOI :
10.1109/CCECE.2002.1012932
