Improved Single-Stream Beamforming Algorithm in TD-LTE System

Beam forming (BF) is a pre-signal processing technique used in sensor arrays for directional signal transmission or reception. It produces directional BF by adjusting the weighted coefficient of each array element to obtain obvious array gain. At present, the most common BF algorithms are eigen-based Beam firming (EBB) algorithm and grid of beam (GOB) algorithm, but these two algorithms still have some defects. Therefore, this paper thoroughly illustrates EBB and GOB algorithms and respectively presents the corresponding improvements. On the one hand, this article proposes a modified EBB algorithm which only adaptively changes phase pattern to reduce the impact on the amplitude of the original signal, thus decreases the power loss. On the other hand, this paper puts forward an improved GOB algorithm which adds the correlation factors of the antennas with different polarization at the same physical position to increase BF gain. The performances of improved and original BF algorithms are simulated in a platform of TD-LTE. The simulation result shows that BLER performances of two enhanced BF algorithms are better than corresponding traditional algorithms.