HIERARCHICAL OVERLAY SYSTEMS: AN ADAPTIVE DETECTION APPROACH
R. Sowmiya1 S. Lenty Stuwart 2 S. Tamilselvi 3
1, 2 University College of Engineering Nagercoil, Anna University, Tamilnadu, India.
3 National Engineering College (Autonomous), Kovilpatti, Tamilnadu, India.
In this paper, we introduce a new adaptive loading technique for multiuser code division multiple access (CDMA) system to achieve improved performance in terms of lower bit-error rate (BER) for active micro-cell users present in the coverage area of a macro-cell base station (BS) which provides basic coverage for a large area. Based on the fading scenario, the proposed scheme adjusts the load distribution among the macro-cell BS and the participating micro-cell BSs in the overlay structure to guarantee relatively low BER to the active mobile stations (MS). The scheme also enables the MS to establish link with one base station at a time to avoid the power disparity from the participating BSs. The superiority of the proposed system in multipath Rayleigh fading channel is shown and also the effect of equal-gain combining (EGC) scheme in system performance is analysed for different BS load.
