Title :
Adaptive beamforming for DS-CDMA using conjugate gradient algorithm in a multipath fading channel
Author :
Mohamed, Nermin A. ; Dunham, James G.
Author_Institution :
Dept. of Electr. Eng., Southern Methodist Univ., Dallas, TX, USA
Abstract :
An antenna array-based base station receiver for wireless DS-CDMA with conjugate gradient (CG) adaptation in a multipath fading channel is studied. In order to construct a beamformer RAKE receiver, the existing code-filtering approach is used for each resolvable multipath component of the desired user, however, with another way to determine the optimum antenna weights. Thus, the desired user´s signal is enhanced and the co-channel interference from other directions is reduced. The average uncoded bit error rate (BER) as a function of the average antenna signal-to-noise ratio (SNR) and the number of receiving antennas is examined in a frequency-selective Rayleigh fading channel. Simulation results show an increase in system capacity proportional to the number of antennas
Keywords :
Rayleigh channels; antenna arrays; array signal processing; cellular radio; channel capacity; cochannel interference; conjugate gradient methods; error statistics; interference suppression; multipath channels; radio receivers; receiving antennas; spread spectrum communication; DS-CDMA; SNR; adaptive beamforming; antenna array; base station receiver; beamformer RAKE receiver; bit error rate; cellular radio; co-channel interference; code filtering; conjugate gradient algorithm; frequency-selective Rayleigh fading channel; interference reduction; multipath fading channel; optimum antenna weights; receiving antennas; signal-to-noise ratio; system capacity; uncoded BER; wireless DS-CDMA; Adaptive arrays; Antenna arrays; Array signal processing; Base stations; Bit error rate; Character generation; Fading; Multiaccess communication; RAKE receivers; Receiving antennas;
Conference_Titel :
Wireless Communications and Systems, 2000. 1999 Emerging Technologies Symposium
Conference_Location :
Richardson, TX
Print_ISBN :
0-7803-5554-7
DOI :
10.1109/ETWCS.1999.897308
