Power allocation method for GMD-based precoded MIMO-OFDM system with reduced feedback

Abstract

A precoding method has been proposed for the wireless systems with limited feedback overhead by properly decomposing the time-domain channel impulse response matrix. For the geometric mean decomposition (GMD)-based precoding, we propose a power allocation method using the upper bound for the bit error rate (BER). Since the objective function is the function of the precoding matrix and power allocation matrix, we also propose an iterative optimization procedure, which uses two separate objective functions to select the precoding matrix from the codebook and find the optimum power allocation simultaneously.