Variable Telemetry Playback Rate for Increased Data Return

In a scheme to increase the overall data return from a phase-modulation, suppressed-carrier telemetry transmitter, the telemetry playback symbol rate is adjusted essentially continuously. More precisely, the playback symbol rate is adjusted frequently (as often as once per symbol period) in small increments. The adjustment of the rate is made in accordance with the principle that the supportable data rate at any given instant is a function of the instantaneous total signal-power-to-noise spectral-density ratio (PT/N0) at the receiver. The scheme was devised for transmission of telemetric data from deep-space missions, but could also be applied to satellites in orbit around the Earth.