Design and Performance Analysis of Adaptive Beamforming Algorithm for Smart Antenna Systems

Beamforming is a technique in which an array of antennas is exploited to achieve maximum reception in a specified direction by estimating the signal arrival from a desired direction while signals of the same frequency from other directions are rejected. This is achieved by varying the weights of each of the sensors (antennas) used in the array. It basically uses the idea that, though the signals emanating from different transmitters occupy the same frequency channel, they still arrive from different directions. We designed and analyzed the performance of Least Mean Square algorithm for the smart antenna system. The proposed algorithm is simulated and analyzed using MATLAB. The results of LMS outputs are studied and compared with different array elements and for different element spacing. One of the simplest algorithms for adaptive processing is based on the Least Mean Square (LMS) error. Although the complexity of the algorithm is very low, its results are satisfying in many cases. The algorithm is very stable and it needs few computations, which is important for system implementation. The performance of LMS algorithm is also compared on the basis of normalized array factor and Mean Square Error (MSE) for Smart Antenna systems. It is observe that the array output acquires and tracks the desired signal after 20 iterations and involves less complexity in design and computation