Digital modulator and digital demodulator

Details Digital modulator and digital demodulator Digital modulator and digital demodulator

1998-04-09

1999-11-16

Chin, Stephen

Pulse or digital communications

Transmitters

Quadrature amplitude modulation

332103, 332125, 455 61, H04L 2736, H03C 300, H03C 304, H04B 100

Patent

active

059870710

ABSTRACT:
A digital modulator and digital demodulator with quadrature amplitude modulation (QAM) schemes, which are designed to modulate or demodulate RZ-coded baseband signals. The digital modulator comprises first to fourth roll-off filters and a first and second inverters connected to the second and fourth roll-off filters. It also comprises a parallel-to-serial converter to successively selects the outputs of the first roll-off filter, third roll-off filter, first inverter, and second inverter. A D/A converter converts the selected digital signal stream into an analog signal. The roll-off filters and inverters operate at a predetermined clock frequency, while the parallel-to-serial converter and the D/A converter work at a frequency four times the predetermined clock frequency. The digital demodulator reverses the above modulation process to reproduce the baseband signals.

REFERENCES:
patent: 5519356 (1996-05-01), Greenberg

Affiliated with

Also associated with

Rating

Digital modulator and digital demodulator does not yet have a rating. At this time, there are no reviews or comments for this patent.

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

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1333823