초록 ▼

There is provided a telemetry system with a receiver which enables detection of pulsed high frequency data (hf) signals in a manner which suppresses noise which may be present within the high frequency bandwidth. The transmitter carrier, which may be subject to some instability, is encoded at a symb

There is provided a telemetry system with a receiver which enables detection of pulsed high frequency data (hf) signals in a manner which suppresses noise which may be present within the high frequency bandwidth. The transmitter carrier, which may be subject to some instability, is encoded at a symbol rate which is generated at a lower frequency than the hf, but which is reliably stable. The receiver detects the phase of each received hf pulse, and generates a phase-locked signal which is synchronized to the transmitter symbol signal. The phase-locked signal in turn is used to demodulate the received pulsed signals. In a specific DSP embodiment, the phase-lock loop has a numerically controlled oscillator which has a center frequency which corresponds to the aliased phase difference between the hf carrier phase and the phase of each pulse, thereby obtaining a signal which carries information as to the exact symbol rate. This information is used either to calculate the timing of a narrow window which gates a pulse detector coincident with each next expected symbol time, or to trigger generation of a replica signal which is used in the detect circuit, thereby providing high resolution detection of the pulses and good noise rejection.

대표청구항 ▼

[ What is claimed is:] [1.]1. A telemetry system for receiving and demodulating transmitted pulsatile high frequency signals, said signals being modulated by a symbol signal having a data symbol rate much less than said high frequency, comprising:demodulator means for receiving said high frequency s

[ What is claimed is:] [1.]1. A telemetry system for receiving and demodulating transmitted pulsatile high frequency signals, said signals being modulated by a symbol signal having a data symbol rate much less than said high frequency, comprising:demodulator means for receiving said high frequency signals and for deriving data symbols from said high frequency signals;phase means for determining the phase of each of said derived symbols;symbol means for developing a symbol signal synchronized in phase with said derived symbols; andfeedback means for generating feedback signals in phase with said symbol signal and for connecting said feedback signals to said demodulator for use in demodulating said high frequency signals.