In this paper, we propose beamforming schemes for frequency-selective channels with decision-feedback equalization (DFE) at the receiver. We consider both finite impulse response (FIR) and infinite impulse response (IIR) beamforming filters (BFFs). In case of IIR beamforming, we are able to derive closed-form expressions for the optimum BFFs. In addition, we provide an efficient numerical method for recursive calculation of the optimum FIR BFFs. Simulation and numerical results for typical GSM/EDGE channels confirm the significant performance gains achievable with beamforming compared to single-antenna transmission and optimized delay diversity.
['Yang-wen Liang', 'Robert Schober', 'Wolfgang H. Gerstacker']
Transmit Beamforming for Frequency-Selective Channels