Receive Beamforming Techniques for an LTE-Based Mobile Relay Station With a Uniform Linear Array

A mobile relay station (MRS) with soft handover experiences performance degradation because the received signal at the MRS located between two base stations (BSs) is the sum of these two signals with different carrier frequency offsets (CFOs). In this paper, two receive beamforming techniques with CFO compensation (a joint receive beamforming (JB) technique and a spatially separated receive beamforming (SB) technique) are proposed for the MRS with a uniform linear array (ULA) in orthogonal frequency-division multiplexing (OFDM) systems. The SB technique is shown to be robust against CFO errors and can be effectively used for the MRS in a multipath fading channel. The performance of the proposed techniques is evaluated via simulation in a Long Term Evolution (LTE) environment.