Arrangement for coherently generating sinusoids of different fre

Details Arrangement for coherently generating sinusoids of different fre Arrangement for coherently generating sinusoids of different fre

1985-07-25

1987-01-06

Griffin, Robert L.

Pulse or digital communications

Repeaters

Testing

375 90, 329112, 364721, H03D 300, H03K 906

Patent

active

046352791

ABSTRACT:
Data signals are angle-modulated onto a carrier in such a fashion as to suppress the carrier. Such modulation may be BPSK, MSK, QPSK, or OPQSK. The carrier may be subject to anomalous phase shifts, as may occur for example when the transmitter and receiver are in relative motion. In order to regenerate the carrier, the received signal is frequency-doubled (or quadrupled in the case of QPSK). The frequency doubled signal is demodulated by means of locally generated double-frequency demodulating signals to form baseband I and Q signals. The I and Q baseband information is evaluated over a predetermined time interval to establish the relative phase between the carrier of the double frequency signal and the double-frequency demodulating signal. At the end of each predetermined interval, the phase of the double-frequency demodulating signal is adjusted to be in-phase with the double-frequency carrier. The double-frequency demodulating signals are generated by addressing memories by at least parts of a recurrent digital sawtooth signal. Carrier-frequency demodulating signals are simultaneously generated by addressing other memories by means of the recurrent digital sawtooth signal. Because of the simultaneous addressing of the memories, the relative phases of the double-frequency and carrier-frequency signals are established by the programming of the memories. When the double-frequency demodulating signals are forced to the correct phase for demodulating the double-frequency signals at the end of each predetermined time interval, the carrier-frequency demodulating signals are also forced to correct phase for coherent low-noise demodulation of the data. The carrier-frequency demodulating signals are used to demodulate data modulated carrier delayed by the predetermined time interval.

REFERENCES:
patent: 4249447 (1981-02-01), Tomisawa
patent: 4331941 (1982-05-01), Kovalick et al.
patent: 4346448 (1982-08-01), Insam et al.
patent: 4412250 (1983-10-01), Smith
patent: 4454486 (1984-06-01), Hassun et al.
patent: 4486846 (1984-12-01), McCallister et al.
patent: 4504786 (1985-03-01), Slaughter
patent: 4529941 (1985-07-01), Lipoff
patent: 4539524 (1985-09-01), Goode
patent: 4563548 (1984-01-01), Misherghi et al.

Affiliated with

Also associated with

Rating

Arrangement for coherently generating sinusoids of different fre does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Arrangement for coherently generating sinusoids of different fre, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Arrangement for coherently generating sinusoids of different fre will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-689617