Coherent detection system

Pulse or digital communications – Receivers – Particular pulse demodulator or detector

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

375354, 342 99, H03D 100, H04L 2706

Patent

active

055861482

ABSTRACT:
A coherent detection system synchronously detects a received wave involving a Doppler shift. To realize a stable demodulation performance, the system has a memory for storing in advance Doppler shifts to be related to an input signal and corresponding pass bands to reduce the bit error rate of restored information to below an allowable maximum when the corresponding Doppler shifts are present; an estimating unit for finding levels of the input signal or instantaneous values R of the input signal that form an envelope, counting the number N per unit time of points where the envelope crosses a threshold, and estimating a Doppler shift fD according to an expression that indicates the ratio of the number N to the Doppler shift fD and involves the in-phase and orthogonal components of the input signal, a distribution of the temporal differentiation of these components, a distribution of power spectra, and the instantaneous values normalized by the threshold; and a band controller for retrieving a pass band corresponding to the estimated Doppler shift fD from the memory and setting the pass band to a filter of the system.

REFERENCES:
patent: 3903525 (1975-09-01), Mullins et al.
patent: 3939428 (1976-02-01), Shimizu et al.
patent: 5272446 (1993-12-01), Chalmers et al.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Coherent detection system does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Coherent detection system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Coherent detection system will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-1998302

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.