A new dual M-ary orthogonal modulation scheme

A new modulation scheme called dual M-ary orthogonal modulation (DMOM) is proposed in this paper. By simultaneously sending one orthogonal sequence through the in-phase branch and the quadrature branch, respectively, this scheme can double the bandwidth efficiency of M-ary orthogonal modulation for a given sequence length M , meanwhile keeps a constant envelope. A ML-based noncoherent detection algorithm and its simplified version are also presented for the demodulation. Finally, the BER performance and computation cost of DMOM are compared with those of the existed QOM.