AT-SAFNAQ algorithm for power allocation in MC-CDMA system

A power allocation algorithm for projection matrix receiver based MC-CDMA system named Adaptive Threshold SAFNAQ (AT-SAFNAQ), has been proposed. SAFNAQ is a combination of frequency domain (FDPA) and eigenvector based (EBPA) power allocation algorithms. SAFNAQ algorithm does not optimize threshold value and it uses same threshold value over different channel realizations. In AT-SAFNAQ, the receiver has an extra unit compared to the receiver used in SAFNAQ algorithm. This extra unit optimizes threshold level adaptively. In accordance with optimum threshold value and the subcarrier gains, the feedback vector is sent to the transmitter for allocation of power. We have compared our results with no power allocation, FDPA, EBPA and SAFNAQ. Simulation results show that AT-SAFNAQ algorithm provides noticeable improvement in performance compared to the algorithms available in literature. We have generated testing bits at transmitter end, passed through Rayleigh fading channel to calculate BER performance of the system at receiver end to verify the results. Moreover, Variances of BER for different users are explored to show that in our system all the users have equal priority.