Title :
Adaptive nonuniform PSK signaling in CDMA wireless communications
Author_Institution :
Clemson Univ., SC, USA
Abstract :
In a code-division multiple-access (CDMA) wireless communication system, the channel characteristics fluctuate for many reasons, including movement of the radios, changes in propagation, and variations in interference. Adaptive signaling can be used to deliver a higher rate of information during good channel conditions while ensuring that a basic level of information is received under all channel conditions. We show that adaptive signaling schemes that employ nonuniform M-ary phase-shift-key (PSK) modulation can be used to increase the throughput in CDMA wireless communication systems with time-varying channels. The signaling method we propose supports the simultaneous transmission of multiple messages with different quality-of-service requirements
Keywords :
adaptive codes; adaptive modulation; code division multiple access; land mobile radio; multiuser channels; phase shift keying; radiofrequency interference; spread spectrum communication; telecommunication signalling; time-varying channels; CDMA wireless communications; PSK modulation; adaptive coding; adaptive nonuniform PSK signaling; channel characteristics; channel conditions; code-division multiple-access; information rate; interference variations; m-sequences; multimedia traffic; multiple messages transmission; nonuniform M-ary phase-shift-key; orthogonal spreading sequences; propagation changes; quality-of-service requirements; radios movement; throughput; time-varying channels; Constellation diagram; Interference; Multiaccess communication; Multimedia systems; Phase shift keying; Quadrature amplitude modulation; Quality of service; Signal design; Throughput; Wireless communication;
Conference_Titel :
Information Theory and Communications Workshop, 1999. Proceedings of the 1999 IEEE
Conference_Location :
Kruger National Park
Print_ISBN :
0-7803-5268-8
DOI :
10.1109/ITCOM.1999.781405
