Claims
- 1. A phase modulation measurement system which measures amounts of steady state phase deviation in a phase modulated telemetry signal produced by a telemetry transmitter, said phase modulation measurement system comprising:
- an input which is electrically coupled to said telemetry transmitter to receive and conduct said phase modulated telemetry signal therefrom;
- a telemetry receiver which receives and demodulates the phase modulated telemetry signal from the input to produce thereby inphase signal and quadrature signal;
- an RF switch which is electrically connected between said input and said telemetry receiver to conduct said phase modulated telemetry signal therebetween;
- a means for digitizing the inphase and quadrature signals from the telemetry receiver to produce a digital series of I samples and Q samples; and
- a computer which receives the I samples and Q samples from the digitizinq means to compute the steady state phase deviation, using a formula given by:
- .phi..sub.ss =[i=i,n arctan (I.sub.i /Q.sub.i)]/n
- where
- .phi..sub.ss one sided steady state phase deviation;
- I.sub.i =each successive I sample across a third bit time;
- and
- Q.sub.i =each successive Q sample across a third bit time.
- n=number of samples, and
- wherein said digitizing means comprises a digital oscilloscope which is electrically connected to said computer to digitize the inphase and quadrature signals into the digitized series of I samples and Q samples.
STATEMENT OF GOVERNMENT INTEREST
The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon.
US Referenced Citations (9)