An adaptive approach to reduce complexity of EBB in LTE downlink TDD systems

As one kind of multiple input multiple output (MIMO) techniques in the 3GPP Long Term Evolution (LTE) and LTE-advanced (LTE-A) systems, eigenvalue based beam-forming (EBB) can maximize the system capacity in single-user scenario. Traditionally, EBB algorithm often takes singular value decomposition (SVD) to the average channel matrix of each resource block (RB) or RB-group. This method is simple but very inflexible, and sometimes it may result in unnecessary high complexity. In this paper, we propose an adaptive approach that combines first order perturbation compensation (FOPC) with traditional SVD to get the beamforming vector or precoding matrix. It has been validated by simulations that our approach can significantly reduce the implementation complexity of EBB with slight performance loss.