Orthogonally multiplexed on-off-keyed amplitude and phase modulation families

By substituting the on-off-keyed signaling for the orthogonal group signaling adopted in two recently reported modulation formats, namely the orthogonally multiplexed orthogonal amplitude modulation (OMOAM) (Chung, 2002) and the orthogonally multiplexed orthogonal phase modulation (OMOPM) (Chung, 2003), the orthogonally multiplexed on-off-keyed amplitude modulation (OMO²AM) family and the orthogonally multiplexed on-off-keyed phase modulation (OMO²PM) family are proposed and investigated in this paper. The power spectral density characteristics of both OMO²AM and OMO²PM signals constructed from typical band-limited and time-limited basis signal sets are studied in terms of fractional power containments. Based on the maximum-likelihood principle, the optimum schemes for coherently demodulating uncoded OMO²AM and OMO²PM signals on the additive white Gaussian noise channel are developed. Union bounds and approximate upper bounds are analyzed and verified by simulation to evaluate the bit error probability characteristics of the optimum schemes. From numerical results, the OMO²AM and OMO²PM schemes are found to provide other good choices of power and spectral efficiencies ranging among the efficiencies achieved by the OMOAM and OMOPM families. When constructed from the practically realizable basis set with rectangularly pulsed quadrature carrier signals, improvement over certain orthogonally frequency-division-multiplexing modulation schemes in both power and spectral efficiencies is also achieved by some OMO²AM and OMO²AM schemes.