M-ary MC-CDMA using quadrature spreading codes for wireless communications system

Author

Zhou, Wuyang ; Xia, Pengfei ; Zhu, Jinkang

Author_Institution

PCN&SS Lab., Univ. of Sci. & Technol. of China, Hefei, China

Volume

1

fYear

2000

fDate

2000

Firstpage

249

Abstract

We present a new modulation method, i.e., M-ary MC-CDMA system with quadrature spreading codes. In the transmitter, M-ary orthogonal modulation is applied to serial-to-parallel converted data bits. The modulated symbol is then spread in the frequency domain using each chip of complex orthogonal codes. Each spread symbol is then modulated on corresponding subcarrier, finally the multiple branches are combined and transmitted. Considering the frequency selective slowly fading, we investigate the system´s downlink performance. Using equal gain combination (EGC) and maximum ratio combination (MRC), we study the effect of complex quadrature spreading codes on the system performance and compare it with that of the single spreading code case. Also we analyse the effect of the guard time on the system and compare it with that of no guard time

Keywords

OFDM modulation; Rayleigh channels; code division multiple access; codes; diversity reception; land mobile radio; multiuser channels; radio links; spread spectrum communication; M-ary MC-CDMA; M-ary orthogonal modulation; OFDM; Rayleigh channel; downlink performance; equal gain combination; frequency domain; frequency selective slowly fading; guard time; maximum ratio combination; mobile radio; modulated symbol spreading; multicarrier modulation; orthogonal codes; quadrature spreading codes; serial-to-parallel converted data bits; single spreading code; subcarrier; transmitter; wireless communications system; Downlink; Fading; Frequency domain analysis; Interference; Modulation coding; Multicarrier code division multiple access; OFDM modulation; Performance gain; Transmitters; Wireless communication;

fLanguage

English

Publisher

ieee

Conference_Titel

Vehicular Technology Conference Proceedings, 2000. VTC 2000-Spring Tokyo. 2000 IEEE 51st

Conference_Location

Tokyo

ISSN

1090-3038

Print_ISBN

0-7803-5718-3

Type

conf

DOI

10.1109/VETECS.2000.851456

Filename

851456