Effective Data Rate Based Rank Adaptive Receive Antenna Selection

In LTE-A downlink, beamforming is adopted to improve spectral efficiency and system capacity. Antenna selection in beamforming selects the proper receive signal subspace on different resource blocks (RBs), which can further improve system performance. In this paper, we first define the concept of effective data rate. Based on such concept, we propose a low complexity antenna selection algorithm for beamforming technology. Different from existing algorithms, the proposed algorithm first determines the data layer number of each user by considering both channel quality and user requirements, and based on the data layer number, it selects a corresponding number of receive antennas to form the receive signal subspace. As a result, dynamic switching between single-layer and dual-layer beamforming can be realized so that user requirements can be better satisfied. Then, the proposed algorithm calculates the spatial correlation to assign proper antennas on different RBs to reduce inter-layer interference. Simulation results show that the effective data rate of the proposed algorithm is higher than other algorithms when user number is bigger than 20 so that the requirements of more users can be satisfied, and user fairness can also be improved.