Precoding Matrix Selection for LTE System

Abstract

In the current 4G Long Term Evolution (LTE) system, it adopts the orthogonal frequency division multiplexing (OFDM) and multiple input multiple output (MIMO) schemes to improve the spectral efficiency and increase the data rate for the system. Besides, precoding is an effective technique in MIMO transmission for the transmitter (Tx) to use a suitable precoding matrix in accordance with the change of the channel. With the proper selected precoding matrix, MIMO system can reduce the multiple access interference and increase the received signal to noise ratio (SNR) at the receiver (Rx). In this paper, two precoding matrix selection methods are proposed via using the features of the beam patterns of the adopted precoding matrices for 3GPP LTE system. With a little performance degradation, the first proposed method has the advantage of low computational complexity and the second method can have the zero latency property compared with the conventional full search methods.