Evaluation of Beamforming for Broadcast Applications in Single Frequency Networks

In this paper, the application of beamforming in a single frequency network (SFN) is examined. A single frequency network is characterized by the transmission of the same signal from multiple base stations simultaneously. Since a user receives the signal from many base stations, the beamforming weights for many different base stations need to be jointly optimized for the transmission. An optimality criterion is given and three different beamforming strategies with varying computational complexity and performance are investigated. Their performances are compared to the case of SFN transmission without beamforming, showing significant gains for realistic numbers of transmit antennas at the base stations and numbers of users in the SFN.