Adaptive Digital Beamforming in Cellular CDMA Systems Using Noniterative Signal Subspace Tracking

We introduce a novel adaptive digital beamforming algorithm for application in cellular CDMA communications systems. A Noniterative Rank-one Signal Subspace eigenstructure Update (NR1SSU) algorithm enables low-complexity recursive processing of beamforming weights. A PN chip-level IS-95 CDMA reference model [3] has been used to test the beamforming algorithm via simulation. Our results show that accurate beamforming can be achieved to moving mobiles at one update per IS-95 frame of 192 data bits. I. Introduction Adaptive antenna array beamforming in future multimedia cellular CDMA communication systems holds great potential for improving signal-to-interference-noise ratios and achieving higher cell capacity. An adaptive beamforming network spatially filters the in-band interfering mobiles by adaptively updating the weight vector of each beamformer so as to steer the main beam lobe to the direction-of-arrival (DOA) of the desired mobile. Traditional eigen-based beamforming techniques ..