System and method for coherent multi-h continuous phase modulation waveform

A method of receiving a data signal transmitted as a continuous phase modulation waveform with a set of modulation indices over a series of different frequencies, wherein the data signal is comprised of a plurality of hopping frames, comprising the steps of:

• (i) demodulating one of the hopping frames at a determined frequency and phase offset with a repeated sequence formed from the set of modulation indices to obtain a set of demodulated data symbols and a set of demodulated other symbols for each frame;
• (ii) decoding the set of demodulated data symbols beginning at state “zero” to recover the data and decoding the set of other symbols to return to the zero phase state;
• and,
• (iii) for a successive hopping frame, transitioning the receiver to a different frequency over a transition period thereby enabling the reception of the transmitted data.

A system for improving the electronic counter-countermeasure (ECCM) capabilities of a multiple modulation indices continuous phase modulation waveform communication system including a receiver, wherein the transmitted data is trellis coded and formed in a plurality of successive data packets, the improvement comprising at the receiver:

• demodulating means for demodulating the data packets at a predetermined frequency and phase offset with a repeated sequence formed from a set of modulation indices thereby forming a set of demodulated symbols;
• decoding means for decoding the set of demodulated data symbols wherein the decoder is sequenced to phase state “zero” at the beginning and end of each data packet;
• and,
• switching means for switching the frequency of the demodulating means to a different frequency for each successive data packet over a predetermined transition period.