Adaptively self-correcting modulation system and method

Modulators – Phase shift keying modulator or quadrature amplitude modulator

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

332107, 332123, 332159, 375 60, H03C 300, H03C 302

Patent

active

053510160

ABSTRACT:
A self-adjusting quadrature modulator and modulation method improve the accuracy with which digital data is impressed on an RF carrier, which is particularly useful for systems having Viterbi, echo-integrating demodulators and for systems using subtractive CDMA techniques. The method and apparatus involve receiving one's own transmission with a suitable modulation assessment receiver and determining the modulation error relative to the theoretically perfect transmission expected by the receiver. The measured error is used to adjust the modulation to minimize the error. The modulation assessment receiver may use log-polar signal processing to measure phase and (log)amplitude instead of cartesian I and Q components, and then convert to cartesian form. In addition, correction factors determined by the modulation assessment receiver can be directly identified with certain transform components produced by the Fast Walsh Transform.

REFERENCES:
patent: 4581749 (1986-04-01), Carney et al.
patent: 4856025 (1989-08-01), Takai
patent: 4899367 (1990-02-01), Sampei
patent: 4953182 (1990-08-01), Chung
patent: 4985688 (1991-01-01), Nagata
patent: 5020076 (1991-05-01), Cahill et al.
patent: 5048059 (1991-09-01), Dent
patent: 5084669 (1992-01-01), Dent
patent: 5105445 (1992-04-01), Karam et al.
patent: 5148373 (1992-09-01), Dent
patent: 5148448 (1992-09-01), Karam et al.
patent: 5151919 (1992-09-01), Dent
patent: 5218619 (1983-06-01), Dent
patent: 5249200 (1993-09-01), Chen et al.
patent: 5293406 (1994-03-01), Suzuki
K. Gilhousen et al., "On the Capacity of a Cellular CDMA System," IEEE Transactions on Vehicular Technology, vol. 40, No. 2, pp. 303-312 (May 1991).
S. Gronemeyer, "MSK and Offset OPSK Modulation," IEEE Transactions on Communications, vol. COM-24, No. 8, pp. 809-820 (Aug. 1976).
F. Stremler, Introduction to Communictions Systems, 2d. Ed., Addison-Wesley Publishing Co., Reading, Mass., pp. 590-596 (1982).

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

Adaptively self-correcting modulation system and method does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Adaptively self-correcting modulation system and method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Adaptively self-correcting modulation system and method will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-1267818

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