Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
204 words
A BPSK synchronizer for bit synchronizing with an output clock a modulated input signal having a sinusoidal carrier frequency of f and a binary modulating signal, where f is much greater than the modulating signal bit rate, said synchronizer comprising: means for taking several samples of the amplitude of the input signal over a sampling interval portion of each modulating signal bit period, wherein the frequency f is an integral multiple of the rate at which said sampling means samples the amplitude of the input signal; coupled to the sampling means, means for recording, for each sampling interval, the total number of samples, the number of samples that change sign with respect to a reference sample, and the number of samples that do not change sign with respect to the reference sample; coupled to the recording means, means for determining a synchronization condition when, within a sampling interval, the number of samples which have been recorded not to have changed sign exceeds a preselected threshold level; and coupled to the determining means, means for generating an output clock synchronized with the modulated input signal, and having a frequency equal to the modulating signal bit rate, when the determining means has determined a synchronization condition.
Claim 2
Dependent Claim
204 words
A BPSK synchronizer for bit synchronizing with an output clock a modulated input signal having a sinusoidal carrier frequency of f and a binary modulating signal, where f is much greater than the modulating signal bit rate, said synchronizer comprising: means for taking several samples of the amplitude of the input signal over a sampling interval portion of each modulating signal bit period, wherein the frequency f is an integral multiple of the rate at which said sampling means samples the amplitude of the input signal; coupled to the sampling means, means for recording, for each sampling interval, the total number of samples, the number of samples that change sign with respect to a reference sample, and the number of samples that do not change sign with respect to the reference sample; coupled to the recording means, means for determining a synchronization condition when, within a sampling interval, the number of samples which have been recorded not to have changed sign exceeds a preselected threshold level; and coupled to the determining means, means for generating an output clock synchronized with the modulated input signal, and having a frequency equal to the modulating signal bit rate, when the determining means has determined a synchronization condition.
Claim 3
Dependent Claim
21 words
The synchronizer of claim 1 wherein the carrier frequency is at least 16 times greater than the modulating signal bit rate.
Claim 4
Dependent Claim
22 words
The synchronizer of claim 1 wherein the reference sample is the first sample taken by the sampling means during each sampling interval.
Claim 5
Dependent Claim
45 words
The synchronizer of claim 1 wherein the sampling means comprises: an analog-to-digital converter having an input coupled to the input signal; and a sampling clock generator, having an input coupled to the input signal, for producing a clock which oscillates at the desired sampling rate.
Claim 6
Dependent Claim
34 words
The synchronizer of claim 1 wherein the recording means determines whether a given sample has changed sign by multiplying the digitized value of the given sample by the digitized value of the reference sample.
Claim 7
Dependent Claim
40 words
The synchronizer of claim 1 further comprising, coupled to the determining means, means for time-shifting the subsequent sampling interval when the number of samples which have been recorded not to have changed sign does not exceed the preselected threshold level.