Multichannel stochastic gradient method for adaptive equalization in uplink asynchronous DS/CDMA

Author

Sirbu, Marius ; Koivunen, Visa

Author_Institution

Signal Process. Lab., Helsinki Univ. of Technol., Finland

fYear

2002

fDate

4-6 Aug. 2002

Firstpage

303

Lastpage

307

Abstract

The paper addresses the problem of channel equalization in asynchronous uplink DS/CDMA systems. An MMSE equalizer is derived based on our proposed channel estimation algorithm (Sirbu, M. and Koivunen, V., Proc. IEEE Int. Conf. on DSP, 2002). For channel estimation, there is no need for knowledge of the propagation delays, whereas for despreading purposes only the chip period multiple of the propagation delays has to be estimated. The proposed scheme processes all user signals simultaneously. The performance is studied based on simulations in non-stationary channel conditions.

Keywords

adaptive equalisers; channel estimation; code division multiple access; delay estimation; gradient methods; least mean squares methods; mobile radio; multipath channels; signal processing; spread spectrum communication; stochastic processes; time-varying channels; DS-CDMA; MMSE equalizer; adaptive equalization; channel equalization; channel estimation; chip period; delay estimation; despreading; mobile stations; multichannel stochastic gradient method; multipath channels; propagation delays; signal processing; time-varying channels; uplink asynchronous DS/CDMA; Adaptive equalizers; Base stations; Blind equalizers; Delay estimation; Gradient methods; Multiaccess communication; Propagation delay; Receiving antennas; Signal processing algorithms; Stochastic processes;

fLanguage

English

Publisher

ieee

Conference_Titel

Sensor Array and Multichannel Signal Processing Workshop Proceedings, 2002

Print_ISBN

0-7803-7551-3

Type

conf

DOI

10.1109/SAM.2002.1191049

Filename

1191049