Method and apparatus for efficient bandwidth communication

A method for improving the bandwidth efficiency of a constant envelope continuous phase modulated waveform signal encoded with data symbols, comprising the steps of varying a complex amplitude of the signal between successive constellation points prior to transmission and controlling the complex amplitude of the signal to follow a path between successive constellation points that is more direct than the arc of a unit circle circumscribing the constellation points.

A method of transmitting data as a non-constant envelope continuous phase modulation signal comprised of a plurality of symbols in a constellation comprising the steps of:

• coding the plurality of symbols into a plurality of CPM symbols;
• and
• transecting ones of said CPM symbols by a direct path during modulation of the coded plurality of symbols thereby enabling the transmission of a non-constant envelope continuous phase modulation waveform.

A method for modulating an input data stream wherein said input data stream is comprised of a plurality of symbols, said symbols represented as constellation positions in a complex plane comprising the steps of generating a continuous phase modulation waveform modulated with the plurality of symbols, and modifying the complex amplitude between the successive constellation positions to traverse the complex plane in a straight path from one of said constellation positions to another of said constellation positions.

In a constant envelope continuous phase modulation waveform communication system including a transmitter for transmitting data as continuous phase modulation symbols and a receiver with a constant envelope continuous phase modulation demodulator, the improvement comprising a conversion means for converting a constant envelope continuous phase modulation waveform into a non-constant continuous phase modulation waveform prior to transmission such that the complex amplitude of the waveform between successive constellation points is less than the complex amplitude at each of the constellation points.

In a method for transmitting an input data stream as phase locations in a complex plane in a continuous phase modulation waveform, the improvement wherein the continuous phase modulation waveform modulated with the input data stream transects the complex plane between successive phase locations in a substantially straight path.

In a method for communicating data that is transmitted as a plurality of symbols within a complex plane as a continuous phase modulated waveform, the improvement wherein the magnitude of the waveform in the complex plane varies during the transition between ones of said symbols.