Downlink beamforming for frequency-duplex systems in frequency-selective fading

Downlink beamforming is analyzed for broadband frequency-duplex systems where frequency-selective fading dominates. In order to compare different beamforming strategies, system level simulations are carried out. It is assumed that at the receiver of the mobile station, path diversity can be exploited. The performance gain from maximal ratio combining of the signal components is evaluated with a new approach that combines system level simulations with an analytical calculation of the probability density function of the signal-to-interference power ratio (SIR) at the output of the combiner.