Phase demodulation method and circuit
AssigneeElenion Technologies, LLC
InventorsBernd-Harald Horst Jurgen Rohde, Richard C. Younce
Life of this patent
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Abstract
An electrical circuit and method for de-modulation and carrier recovery of PSK modulated carrier signals in analog domain are described. A portion of the received PSK-modulated carrier signal is passed through a signal multiplication circuit to obtain a frequency-multiplied carrier that is absent of the PSK modulation, which is then passed through a frequency dividing circuit to obtain a reference carrier at the received carrier frequency. The reference signal is then mixed with the received PSK-modulated carrier signal to obtain a de-modulated baseband signal. The method may be used in heterodyne receivers of optical BPSK and QPSK signals.
Claims21
1-20. (canceled)
A method for demodulating a received phase shift keying (PSK) signal, the method comprising:
- splitting the received PSK signal into a first PSK signal and a second PSK signal, each comprising a PSK-modulated carrier wave with a carrier wave frequency f that may vary in time;
- multiplying the first PSK signal upon itself at least once to obtain a frequency-multiplied carrier signal absent of PSK modulation;
- using one or more frequency dividing flip-flop circuits to obtain, from the frequency multiplied carrier signal, a first reference carrier wave signal at the carrier wave frequency f;
- and,
- mixing the first reference carrier wave signal with the second PSK signal to obtain a first de-modulated signal.
An electrical circuit for demodulating a received PSK signal, the electrical circuit comprising:
- a first signal splitter configured to split the received PSK signal into a first PSK signal and a second PSK signal, each comprising a PSK-modulated carrier wave with a carrier wave frequency f;
- a multiplying circuit configured to convert the first PSK signal into a frequency-multiplied carrier signal absent of PSK modulation;
- a frequency dividing circuit comprising one or more flip-flop circuits and configured to convert the frequency multiplied carrier signal into a first reference carrier wave signal at the carrier wave frequency fin the absence of frequency or phase locking;
- and,
- a first electrical signal mixer configured to mix the first reference carrier wave signal with the second PSK signal to extract a first de-modulated signal from the second PSK signal.
Dependencies are inferred from the claim text.