Efficient PIC Technique for Performance Improvement in Synchronous CI/MC-CDMA Uplink Using Fuzzy Logic

This paper investigates the scope of usage of fuzzy logic to beat the effect of multiple access interference (MAI) through block parallel interference cancellation (BPIC) in a synchronous Carrier Interferometry/MC-CDMA uplink system. The users are classified in different blocks like very strong, strong, weak and very weak based on fuzzy membership function derived from the magnitude of the received signal strength. BER (bit error rate) performance of BPIC is then analyzed by carrying out simulation on frequency selective Rayleigh fading channel. We have reported the performance of the system in terms of BER and number of users for conventional PIC, four block PIC, three block PIC and two block PIC. A significant improvement in BER and capacity is seen with block PIC based on fuzzy logic relative to conventional PIC at the cost of a slight increase in computation complexity. Simulation results show that BER is reduced as the number of users are classified in more number of blocks using the fuzzy membership function. BER performance of the system is also reported for weighted two block PIC based on fuzzy logic and for two block PIC.