Title :
Efficient MIMO equalization for downlink multi-code CDMA: complexity optimization and comparative study
Author :
Guo, Yuanbin ; Zhang, Jianzhong ; McCain, Dennis ; Cavallaro, Joseph R.
Author_Institution :
Nokia Res. Center, Irving, TX, USA
fDate :
29 Nov.-3 Dec. 2004
Abstract :
We present an efficient LMMSE chip equalizer to suppress the interference caused by the multipath fading channel in the MIMO multi-code CDMA downlink. The block-Toeplitz structure in the correlation matrix is approximated with a block circulant matrix. An FFT-based algorithm is applied to avoid the direct-matrix-inverse (DMI) in the system equation. Hermitian optimization is proposed to further reduce the complexity. A comparative study in both performance and complexity with the conjugate-gradient (CG) algorithm is then presented. The simulation shows very promising results for the FFT-based equalizer compared with both the DMI and CG algorithms.
Keywords :
MIMO systems; Toeplitz matrices; cellular radio; code division multiple access; computational complexity; conjugate gradient methods; correlation methods; equalisers; fading channels; fast Fourier transforms; interference suppression; least mean squares methods; multipath channels; optimisation; FFT-based algorithm; Hermitian optimization; MIMO equalization; block circulant matrix; block-Toeplitz structure; cellular systems; chip equalizer; complexity optimization; conjugate-gradient algorithm; correlation matrix; direct-matrix-inverse; downlink multi-code CDMA; interference suppression; multipath channel; multipath fading channel; Character generation; Downlink; Equalizers; Fading; Interference suppression; Intersymbol interference; Iterative algorithms; MIMO; Multiaccess communication; Receiving antennas;
Conference_Titel :
Global Telecommunications Conference, 2004. GLOBECOM '04. IEEE
Print_ISBN :
0-7803-8794-5
DOI :
10.1109/GLOCOM.2004.1378459
