Behavior of modified MVDR beamformer algorithm with realistic scenario

Abstract

Smart antenna is a system based on the antenna elements which are distributed uniformly as array and on the beamformig (BF) algorithm. Each element in the array receives the wave plane signals individually, and then, the beamformer tries to produce the optimum weight for each element with respect to the reference element in the array. This technique is called beamforming. MVDR is one of the most important algorithms that provide optimum weight. The array elements are weighted to direct the main beam of the transmitted energy to the direction of the desired signal as well as direct null towards undesired signal. Mismatch may be occurs due to the location of reference element within the array. Mismatch in MVDR leads to suppress the desired signal and treats as interference. This paper presents a new technique to re-localize the selected reference element within the array. The reference element is chosen to be in the middle of the array instead of one end side of the array. The new location becomes more realistic with respect to received signals directions. Simulation results clarify that the modified MVDR overcomes the mismatch and self null phenomena in classical MVDR.