Synchronous double sideband suppressed carrier multichannel system

Claim 1

In a multichannel telemetry system utilizing transmitted double-sideband supressed-carrier amplitude-modulated subcarrier signals; a. a transmitter including: i. a plurality of sources of continuous subcarrier signals each corresponding to a different channel; ii. a plurality of sources providing sometime discontinuous data signals each to be transmitted over a different one of said channels to which it corresponds; iii. at least one source providing a continuous highly stabilized reference signal having a frequency outside the band of said data signals; iv. a plurality of modulating means each corresponding to a different one of said channels and connected to sAid subcarrier and data signal sources for the channels to which they correspond each for generating a double-sideband suppressed-carrier transmission signal corresponding to their respective channels; v. means for combining said double-sideband suppressed-carrier transmission signals generated by said plurality of modulating means into a composite signal; vi. means for adding an independently recoverable form of said reference signal with said composite signal; b. a receiver for demodulating said transmission signal including; i. means operable to independently recover both said composite and independent reference signals; ii. means for separating said composite signal into doublesideband suppressed-carrier signals each corresponding to a different one of said channels; and iii. a plurality of systems of the following components each corresponding to a different one of said channels for demodulating different ones of said last-named double-sideband suppressed-carrier signals; 1. means responsive to said double-sideband suppressed-carrier signals for generating a waveform of fundamental frequency twice that of one of said subcarrier signals; 2. scaling means connected to said waveform generating means and being productive of a wave having the frequency of said last-named subcarrier signal; 3. demodulating means responsive to said last-named doublesideband suppressed-carrier signal and said wave for generating a demodulated output signal which includes both said data and reference signals for its respective channel; 4. means responsive to said demodulated output signal for recovering said reference signal therefrom; 5. phase detector means responsive to the application of said independently recovered reference signal and said demodulated output signal for developing a control signal which varies in accordance with the difference in phase between said independently recovered and reference signal and said reference signal included in said demodulated output signal; 6. means for applying said control signal to said scaling means for adjusting the phase of said wave; and 7. means connected to said demodulating means and responsive to said demodulated output signal for deriving said data signal for said channel.

Claim 24

A system for telemetering discontinuous information signals from a transmitting point to a receiving point comprising: a. a source of continuous reference signals of constant frequency at said transmitting point; b. means at said transmitting point responsive to said information signals and said reference signals for generating a double-sideband suppressed-carrier signal amplitude-modulated in accordance with both said reference and information signals, said amplitude-modulated signal thereby being a composite signal; c. means at said receiving point responsive to said composite signal for recovering said suppressed-carrier including an oscillator and means for synchronizing said oscillator at a frequency determined by the repetition rate of said composite amplitude-modulated signal; and d. synchronous demodulation means at said receiving point responsive to said recovered suppressed-carrier and said amplitude-modulated signal for deriving an output including said information signals and said reference signals.

Claim 25

A system for telemetering discontinuous information signals from a transmitting point to a receiving point comprising: a. a source of continuous reference signals of constant frequency at said transmitting point; b. means at said transmitting point responsive to said information signals and said reference signals for generating a double-sideband suppressed-carrier signal amplitude-modulated in accordance with both said reference and information signals, said amplitude-modulated signal thereby being a composite signal; c. means at said receiving point responsive to said composite signal for recovering said suppressed-carrier including an oscillator and means for synchronizing said oscillator at a frequency determined by the repetition rate of said composite amplitude-modulated signal; and d. synchronous demodulation means at said receiving point responsive to said recovered suppressed-carrier and said amplitude-modulated signal for deriving an output including said information signals and said reference signals.