MMSE Partially Connected Hybrid Beam Forming in MIMO-OFDM Systems

Lenin SB, N Tamilarasan and

Abstract

Traditionally, Multi Input Multi Output-Orthogonal Frequency Division Multiplexing (MIMO-OFDM) technique is utilized to increase the diversity gain and to suppress the Inter Carrier Interference (ICI) to some extent. The problem of the existing system is to solve the sum rate maximization due to non-convexity. This paper aims to minimize the computational cost at the transceiver side and improve the spectral efficiency. This paper presents a minimum mean square error (MMSE) approach for partially connected Hybrid beam forming (HBF) weighted sum rate maximization.Since the feedback of the BF system is more complicated, one-bit training is used to minimize the complications rather than a large bit training method. The paper gives more attention on BF technique for an IEEE802.11ad standard to transmit and receive the data. The proposed method focuses on the reduction of the complexity level, increases the spectral and power efficiency with an optimal number of radio frequency (RF) links. The MMSE estimation validates the results by comparing with various methods such as analog BF and fully digital in terms of loss calculation, sumrate and normalized MSE. The analysis results are showed that MMSE attains optimal spectral and power efficiency.