Multicarrier CDMA with adaptive frequency hopping for mobile radio systems

Abstract

Abstract-A modified multicarrier (MC) direct-sequence codedivision multiple-access (DS-CDMA) system has been proposed for use over slow multipath fading channels with frequency selectivity in the reverse link transmission of a cellular network. Instead of transmitting data substreams uniformly through subchannels, data substreams hop over subchannels with the hopping patterns adaptively adjusted to the channel fading characteristics. The problem of determining the optimal hopping pattern is formulated as a multiobjective optimization problem, for which an efficient algorithm, based on the water-filling (WF) principle, is designed to solve the problem practically. Simulation results show that the performance in terms of the average bit-error probability (BEP) (over all users) is better than that of single carrier RAKE receiver systems, conventional MC CDMA systems applying moderate error protection, or diversity systems with different combining techniques.

Unlocking Signal Processing With Image Detection: A Frequency Hopping Detection Scheme for Complex EMI Environments Using STFT and CenterNet

“…Frequency hopping (FH) signals have been increasingly utilized in civilian and military communications. Since their invention, the robust anti-interference capability, low interception probability, and excellent anti-fading effect have made it possible to diversify the human use of electromagnetic waves [1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12]. For instance, Code Division Multiple Accessbased 3G cellular communications significantly enhance the channel capacity; however, the multipath effect may distort the frequency identification of FH carriers, leading to an elevated Bit Error Rate.…”