Colorado Advanced Software Institute Feasibility Study for Qualcomm-cdma-based System in Wireless Lans Collaborating Company: Tom Sesnic Qualcomm Incorporated Representative Project Title: Feasibility Study for Qualcomm-cdma-based System in Wireless Lans

In this report, we proposed a DS-CDMA-based WLAN architecture which provides integrated services. Then we studied the channel characteristics for indoor wireless LAN's. Random amplitude, path delay and phase sequences of the channel response have been studied extensively here.For the distribution of the arrival time sequence, it is found that the modi ed Poisson model: K Model is better over the standard Poisson model; When temporal variations caused by moving persons around base station or portable station are present, Rician model is better than Rayleigh model; A reasonable assumption is that, on the global basis, the phase is uniformly distributed in [0; 2 ). The study of frequency dependence of the channel model statistics reveals that, in general, channel's statistics have greater variations with the type of environment than with the frequency, another observation is that the path loss is less severe at lower frequency than at higher frequency. From the study of coding, modulation and detection techniques, we found the optimum coding/modulation scheme for our system, the results also serve as general guide for designing other DS-CDMA systems. The study on e ciency of the multiaccess protocol reveals that spread ALOHA is a highly e cient multiaccess protocol for small values of throughput and low transmission signal-to-noise ratio considered in this system.