Title :
Blind multiuser channel estimation in time-varying direct sequence code division multiple access systems
Author :
Luo, Weilin ; Tugnait, Jitendra K.
Author_Institution :
Dept. of Electr. & Comput. Eng., Auburn Univ., AL, USA
Abstract :
A multistep linear prediction (MSLP) approach is presented for blind channel estimation for short-code DS-CDMA (direct sequence code division multiple access) signals in time-varying multipath channels. The time-varying channel is assumed to be described by a complex exponential basis expansion model (CE-BEM). We first extend a recently proposed MSLP approach to blind channel estimation for time-varying SIMO (single-input multiple-output) systems, to time-varying MIMO systems in order to define a "signal" subspace. Then, the knowledge of the spreading code of a desired user is exploited in conjunction with the signal subspace to estimate the time-varying channel of the desired user. Sufficient conditions for channel identifiability are investigated. An illustrative simulation example is provided.
Keywords :
MIMO systems; channel estimation; code division multiple access; codes; multipath channels; multiuser channels; prediction theory; spread spectrum communication; time-varying channels; MIMO systems; SIMO systems; blind channel estimation; blind multiuser channel estimation; channel identifiability; complex exponential basis expansion model; multipath channels; multistep linear prediction; short-code DS-CDMA; signal subspace; single-input multiple-output systems; spreading code; time-varying channels; time-varying direct sequence code division multiple access systems; Additive white noise; Direct-sequence code-division multiple access; Dispersion; Frequency; Hydrogen; MIMO; Multiuser channels; Time factors; Time varying systems; Time-varying channels;
Conference_Titel :
Acoustics, Speech, and Signal Processing, 2003. Proceedings. (ICASSP '03). 2003 IEEE International Conference on
Print_ISBN :
0-7803-7663-3
DOI :
10.1109/ICASSP.2003.1202673
