| 摘要 |
A separate reference generator, operated from an independent clock oscillator, is selectively controllable to generate different time-compressed reference signals for comparison to received signals during each recirculation of a time compressor circuit. Since the selectively variable reference signal is an analogue signal, the output of a correlation processor is linearly related to a correlation coefficient existing between the reference signal and the received signal, for signals with Gaussian characteristics. Having the reference signal derived from a clock oscillator in the correlation processor, that is distinct from the oscillator generating the transmitted signal, allows variation of the reference signal's waveform, particularly with respect to phase, to provide correlation with doppler-shifted received signals. A real-time correlation signal processor, utilizing a single time compressor in the receive channel, and a separate signal generator in the reference channel cooperate to correlate time-compressed replicas of the transmitted signal with a reference signal having substantially the same frequency. The complexity of the real-time active correlation signal processor circuitry is reduced and its flexibility and usefulness for a wider number of applications is increased.
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