Method and apparatus for digital vector QAM modulator

Details Method and apparatus for digital vector QAM modulator Method and apparatus for digital vector QAM modulator

2004-03-10

2009-02-17

Torres, Juan A. (Department: 2611)

Pulse or digital communications

Transmitters

Quadrature amplitude modulation

C375S261000, C332S103000, C332S151000

Reexamination Certificate

active

07492832

ABSTRACT:
Direct digital QAM modulation at an RF frequency is obtained from digitally synthesized RF signals which are generated for use as the two vectors. The two vectors are individually controlled in phase and summed to provide a combined phase and amplitude modulation that forms the modulated signal. The synthesized RF signal is generated from a higher reference frequency using a variable pulse stretching technique implemented with programmable delay lines. The amount of the pulse stretch in each cycle is controlled by a phase increment value. Pulse stretching can be extended beyond one cycle by pulse swallowing, allowing the generation of an RF signal from DC up to and including the input reference frequency. Phase modulation is added by digital control of the pulse stretching according to the phase modulation data bits.

REFERENCES:
patent: 5329259 (1994-07-01), Stengel et al.
patent: 5612651 (1997-03-01), Chethik
patent: 5627500 (1997-05-01), Wolaver et al.
patent: 5659272 (1997-08-01), Linguet
patent: 5714896 (1998-02-01), Nakagawa et al.
patent: 5852389 (1998-12-01), Kumar et al.
patent: 5867071 (1999-02-01), Chethik
patent: 6366177 (2002-04-01), McCune et al.
patent: 6373902 (2002-04-01), Park et al.
patent: 2002/0097790 (2002-07-01), Dress et al.
patent: 2004/0037363 (2004-02-01), Norsworthy et al.
patent: 2005/0163248 (2005-07-01), Berangi et al.

Affiliated with

Also associated with

Rating

Method and apparatus for digital vector QAM modulator does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method and apparatus for digital vector QAM modulator, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for digital vector QAM modulator will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-4117256