CFO-Resistant Receiver for Asynchronous MC-DS-CDMA Systems

In this paper we propose a new receiving algorithm for MC-DS-CDMA systems when carrier frequency offset (CFO) is significant. By exploiting the special structure of the CFO contaminated signals, the new algorithm cancels CFO completely during the despreading procedure, after which the despreaded CFO-free signal is demodulated via normal FFT-based OFDM demodulator. Guaranteeing complete CFO cancellation, this method is advantageous over the majority existing CFO-mitigation techniques that can only mitigate but not completely remove CFO. An efficient algorithm is developed, and simulations are conducted to demonstrate the performance.