Smart Antenna Techniques for Interference Suppression in WCDMA Using LMS Algorithm

In recent years there has been an explosive growth in the number of wireless users, particularly in the area of mobile communication. This growth has triggered an enormous demand not only for capacity but also for better coverage and higher quality of service without increase in radio frequency spectrum allocated for mobile applications. Smart antennas dynamically adapt to changing traffic requirements whose adaptive beam forming approach can be studied with the help of different adaptive algorithms. In the present paper the interference suppression capabilities of the smart antenna in WCDMA are studied with the help of LMS algorithm. The performance of the algorithm is studied with different parameters such as effect of number of antenna elements, the inter element spacing, the number of interferers and SNR in detail. The simulation results shows that increasing the number of antenna elements results in sharper beams and the optimum value of inter element spacing is half wavelength. When the intra cell frequency reuse is increased, an increased number of antenna elements beyond the theoretical limit produce a better result. KeywordsSmart Antenna, LMS Algorithm, Beam Formation, Null Steering.