Carrier recovery arrangement for sixteen-state amplitude and pha

Details Carrier recovery arrangement for sixteen-state amplitude and pha Carrier recovery arrangement for sixteen-state amplitude and pha

1982-04-09

1984-08-14

Safourek, Benedict V.

Pulse or digital communications

Repeaters

Testing

329112, 329135, 375 39, H03D 322

Patent

active

044661096

ABSTRACT:
Carrier recovery arrangement in a receiving system for digital data which are transmitted by sixteen-state amplitude and phase modulation (16 QAM), the arrangement having, successively six parallel paths (V.sub.1 -V.sub.6) each including the series arrangement of a multiplying circuit (M.sub.i) and a low-pass filter (F.sub.i); a selection circuit for selecting one of the three pairs of filter output signals thus obtained; a phase control circuit having a Costas signal processing circuit receiving the selected pair of signals and producing a signal representative of the phase error of the received signal, a filter and a voltage-controlled oscillator; and a phase-shifting circuit receiving the output signal of the oscillator in order to couple this output signal to respective second inputs of the multiplying circuits (M.sub.1)-(M.sub.6), this signal coupling being effected with a phase shift zero for (M.sub.1), .theta. for (M.sub.3), 2.theta. for (M.sub.5), and with a phase shift .pi./2 for (M.sub.2), .theta.+.pi./2 for (M.sub.4), and 2.theta.+.pi./2 for (M.sub.6), where .theta. is equal to tan.sup.-1 (1/2).

REFERENCES:
patent: 4084137 (1978-04-01), Welti
patent: 4255713 (1981-03-01), Yoshida
patent: 4330861 (1982-05-01), Impallomeni et al.

Affiliated with

Also associated with

Rating

Carrier recovery arrangement for sixteen-state amplitude and pha does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Carrier recovery arrangement for sixteen-state amplitude and pha, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Carrier recovery arrangement for sixteen-state amplitude and pha will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-117685