A High-Rate Low-PAPR Multicarrier Spread Spectrum System Using Cyclic Shift Orthogonal Keying

A bandwidth and power efficient multi-code multicarrier spread spectrum (MCSS) system is proposed in terms of a new cyclic shift orthogonal keying (CSOK) scheme. The system can operate in either the Hybrid CSOK (HCSOK) mode which combines PSK/QAM with CSOK, or the Quadrature CSOK (QCSOK) mode which provides higher data rate. Under dispersive channel, efficient maximum likelihood receivers are derived for both modes. It is shown that the CSOK MCSS system can outperform the traditional single-code MCSS system in terms of bandwidth efficiency, PAPR, and bit error rate. Furthermore, under indoor multipath fading channel, the QCSOK receiver performs only slightly inferior to the QPSK-CSOK receiver, while achieving almost twice the data rate of the later.