Adaptive CPFSK signaling

An adaptive CPFSK (continuous-phase frequency-shift keying) signaling technique which achieves the maximum constraint length allowed by the number of states of the signals is introduced. Adaptive CPFSK signals select modulation indices dependent on both the transmitted symbol and the state of the system. These signals employ the same set of modulation indices during all signaling intervals. The state transition matrix of the signaling system is used to select the modulation indices. Numerical results obtained for binary full-response and partial-response signaling indicate that adaptive CPFSK signaling performs significantly better than MSK (minimum-shift keying) signaling at almost the same spectral occupancy.<
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