A new class of MC-CDMA systems using cyclic-shift M-ary biorthogonal keying

In this paper, a new class of MC-CDMA systems is proposed, which uses cyclic-shift M-ary biorthogonal keying (CS-MBOK) symbol mapping in terms of the polyphase Chu sequence with perfect autocorrelation function. In addition to the basic CS-MBOK mode, we also propose three other transmission modes for more flexible data rate and performance tradeoff in different applications. A low-complexity structure for CS-MBOK code correlation and demapping based on FFT/IFFT is also devised. Compared to the conventional MC-CDMA system, the new system is featured of greatly improved bandwidth efficiency and BER performance, and much lower peak-to-average power ratio (PAPR) of the transmit signal, especially for larger FFT size. Simulation results are included to confirm the above arguments