Title :
A constant amplitude coding for code select CDMA system
Author :
Kim, Sung Pil ; Kim, Myoung Jin
Author_Institution :
Hankuk Univ. of Foreign Studies, Kyonggi-do, South Korea
Abstract :
Multi-code CDMA is an appropriate scheme for transmitting high rate data. However, the dynamic range of the signal is large, and a power amplifier with good linearity is required. Code select CDMA (CS/CDMA) is a variation of the multi-code CDMA scheme that ensures constant amplitude transmission. In CS/CDMA the input data selects orthogonal codes for spreading other input data. In a conventional CS/CDMA system a multi-level signal is MPSK modulated for transmission. To limit the number of levels, the system includes a level clipping block, which may destroy orthogonality between channels and causes performance degradation. We show that by encoding the input data amplitude of the output signal can be made constant. With the proposed coding scheme, level clipping is not necessary and the output signal can be BPSK modulated for transmission.
Keywords :
code division multiple access; data communication; encoding; multiuser channels; phase shift keying; spread spectrum communication; CS/CDMA; MPSK; code select CDMA system; constant amplitude coding; constant amplitude transmission; high rate data transmission; input data amplitude encoding; input data spreading; multi-code CDMA; multi-level signal; orthogonal codes; output signal; power amplifier; signal dynamic range; wireless multimedia communication services; Bandwidth; Binary phase shift keying; Degradation; Gain; Modulation coding; Multiaccess communication; Pulse amplifiers; Pulse width modulation; Space vector pulse width modulation; Transmitters;
Conference_Titel :
TENCON '02. Proceedings. 2002 IEEE Region 10 Conference on Computers, Communications, Control and Power Engineering
Print_ISBN :
0-7803-7490-8
DOI :
10.1109/TENCON.2002.1180300
