Performance improvements of integrated voice and data transmission in DS-CDMA

Author

Hirose, Shouichi ; Nishio, Akihiko ; Yoshida, Susumu

Author_Institution

Graduate Sch. of Inf., Kyoto Univ., Japan

Volume

2

fYear

2000

fDate

2000

Firstpage

780

Abstract

We propose two schemes which improve the performance of integrated voice and data transmission in DS-CDMA systems. One is an interference canceller combined with two packet detectors. The first packet detector sounds a propagation channel, estimates delayed paths of data packets with the use of periodically inserted pilot symbols in each packet, and then demodulates data packets temporarily by RAKE combining. These estimated delayed paths are incorporated into the interference canceller so as to enhance the cancelling capability and to improve the voice signal quality. Then, by separating voice signals from a received signal, data packets can be more reliably detected by the second packet detector. The other is a power control scheme for data packets which avoids the degradation of the voice signal quality. In this scheme, data packets are transmitted with smaller power when the number of active voice users gets larger. The performance improvements are confirmed at the cost of slight increase of transmission delay of data packets by computer simulations

Keywords

code division multiple access; delays; integrated voice/data communication; interference suppression; multiuser channels; personal communication networks; radio receivers; radiofrequency interference; signal detection; speech intelligibility; spread spectrum communication; RAKE combining; computer simulations; data packets; data transmission; delayed paths estimation; demodulation; integrated voice/data transmission; interference canceller; packet detectors; performance improvements; periodically inserted pilot symbols; power control; propagation channel sounding; received signal; transmission delay; voice signal quality; wireless personal communication systems; Acoustic propagation; Costs; Data communication; Degradation; Delay estimation; Detectors; Interference cancellation; Multiaccess communication; Power control; Propagation delay;

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.2000.851231

Filename

851231