Design of Efficient Adaptive Beamforming Algorithms for Novel MIMO Architectures

Abstract

The major issue in the mobile communication is the presence of several types of im- pairments in the wireless medium. There are many types of impairments, the important one is refer to as fading which is defined as the interference occurred in the received signal because of its multiple copies arrived through multi paths. It creates considerable changes in receive signal power and therefore counted as significantly destructive in nature. Fading introduces significant distortion and disturbances in almost all wireless radio signal. The major cause of the fading is multipath propagation of the signals and the relative movement of mobile transmitting and/or receiving device. The cancellation of fading effect is essential to achieve higher data rate and better ser- vice quality with similar radiating power and/or bandwidth. Diversity is one of the im- portant techniques to reduce the effect of fading. In order to achieve different diversity types multiple input multiple output antenna array is employed. If a switchable or movable beam pattern is connected to multiple input multiple output (MIMO) antenna system; the system is referred to as smart system. In order to perform xivthis function, smart antenna requires certain signal processing and adaptive computa- tion. Such adaptive computations are performed through some algorithms known as adaptive beamforming algorithms. This dissertation develops three novel MIMO beamforming architecture using decision directed mode in order to exploit spatial and temporal diversities. Moreover, we pro- posed three new adaptive beamforming algorithms for fast convergence and high beam gain. The simulation results prove their effectiveness over other available algorithms and architectures.