Improved efficiency CDMA by constant envelope SQAM

Author

Wan, Zhen ; Feher, Kamilo

Author_Institution

Dept. of Electr. & Comput. Eng., California Univ., Davis, CA, USA

fYear

1992

fDate

10-13 May 1992

Firstpage

51

Abstract

In order to reduce the interference into the adjacent channel and to increase the processing gain of the CDMA system, a power and spectral efficient superposed-quadrature-amplitude-modulation code-division-multiple-access (SQAM-CDMA) system is proposed. In the hard-limited power amplified channel, SQAM-CDMA has about 12-16 dB lower out-of-band power interference into the adjacent channel than that of QPSK-CDMA, and 11-15 dB lower than that of BPSK-CDMA. Assuming a 30 dB lower out-of-band interference power is required in a given RF bandwidth, the processing gain of SQAM-CDMA is increased by 7 dB over QPSK-CDMA and 9.5 dB over BPSK-CDMA in the hard-limited amplified channel

Keywords

amplitude modulation; code division multiple access; interference suppression; mobile radio systems; spread spectrum communication; CDMA; adjacent channel interference reduction; constant envelope SQAM; efficiency; hard-limited power amplified channel; mobile communications; processing gain; spread spectrum communication; superposed-quadrature-amplitude-modulation code-division-multiple-access; Bandwidth; Baseband; Demodulation; High power amplifiers; Low pass filters; Multiaccess communication; Radio frequency; Radiofrequency interference; Robustness; Signal processing;

fLanguage

English

Publisher

ieee

Conference_Titel

Vehicular Technology Conference, 1992, IEEE 42nd

Conference_Location

Denver, CO

ISSN

1090-3038

Print_ISBN

0-7803-0673-2

Type

conf

DOI

10.1109/VETEC.1992.245399

Filename

245399