An efficient capacity improvement technique for multiuser DS-CDMA-based fixed wireless applications

Abstract

In Fixed Wireless Applications (FWA), the Direct Sequence Code Division Multiple Access (DS-CDMA) is the most promising candidate for wideband data access. The reason is the high throughput and soft limit on the number of active mobile devices. Soft limit on the network capacity means degradation of the performance by increasing the number of mobile devices. In many Fixed Wireless Applications, it is required to maintain the Bit Error Rate (BER) within some tolerable limits for a given SNR. This results in restriction on the number of mobile devices in the network. The number of active mobile devices or network capacity is further reduced by the mutual interference among the users caused due to multipath fading effects and synchronization problems. This paper presents an effective method of improving the capacity of CDMA based Fixed Wireless Networks by using a multiuser detection based power management framework. The system is simulated in the multipath channel models for fixed wireless applications. The proposed scheme increases the capacity two times as compared to the conventional CDMA based networks. Simulation results have been presented to demonstrate the effectiveness of the proposed scheme.