Hybridization of zero forcing-minimum mean square error equalizer in multiple-input multiple-output system

Abstract

Transmission of high data rate over multipath environment is associated with many wireless applications. However, this transmission results in high delay which leads to inter-symbol interference (ISI) distortion and causes high error. The existing linear equalizer (LE) in multiple-input multiple-output (MIMO) systems such as zero forcing (ZF) equalizer used in addressing this problem reduces the ISI distortion completely but results in noise amplification. Likewise, minimum mean square error (MMSE) equalizer only reduces the noise but cannot eliminate ISI. Therefore, this paper proposed a hybrid LE for wireless fidelity (Wi-Fi) over Weibull fading channel. The hybridized ZF-MMSE equalizer was developed using conventional ZF and MMSE equalizers. Digital transmitted signal propagated over Weibull fading channel is received at the receiver through multiple antennas and then combined using maximal-ratio combining (MRC). The combined signal is then equalized using hybrid ZF-MMSE to eliminate both the ISI and the amplified noise. The developed model was simulated in MATLAB software environment and evaluation was performed using bit error rate (BER) and pout. The results obtained revealed that the hybrid ZF-MMSE equalizer gave better performance over existing equalizers in a MIMO system. Therefore, the proposed equalizer will help improve the performance of the Wi-Fi technology.