Transmitter and receiver for an othogonally multiplexed QAM sign

Details Transmitter and receiver for an othogonally multiplexed QAM sign Transmitter and receiver for an othogonally multiplexed QAM sign

1980-02-15

1981-11-10

Olms, Douglas W.

Multiplex communications

Wide area network

Packet switching

370 70, H04J 1100, H04J 102

Patent

active

043002293

ABSTRACT:
In a transmitter for digitally converting PAM signals, 2L in number, of a common slow sampling rate of 1/T hertzes to an orthogonally multiplexed QAM signal of a fast sampling rate of N/T hertzes, N/2-point input data into which the PAM signals are pre-processed with addition thereto of dummy signals, only (N/2-L) in number, are supplied to at least one N/2-point ODFT (offset discrete Fourier transform) processor (61), a pair of which (61, 62) must have been an N-point ODFT processor accompanied by switches controlled at a T/2-second period. After caused to pass through respective filter units of a bank (71), N/2-point output data are time-division multiplexed into the QAM signal. The filter units may either be complex band-pass or real low-pass filter units. A receiver comprises similar parts and carries out entirely reversed operation.

REFERENCES:
patent: 3891803 (1975-06-24), Daguet et al.
"Performance of an Efficient Parallel Data Transmission System" by Saltzberg, IEEE Trans. on Comm. Theory, vol. COM-15, No. 6, Dec. 1967, pp. 805-811.
"An Improved Method for Digital SSB-FDM Modulation and Demodulation" by Maruta et al., IEEE Trans. On Comm., vol. COM-26, No. 5, May 1978, pp. 720-725.
Theory and Application of Digital Signal Processing by Rabiner et al., 1975, pp. 552-555, and 596-621.
Digital Signal Processing by Peled et al., 1976, pp. 145, 153, 155 and 156.

Affiliated with

Also associated with

Rating

Transmitter and receiver for an othogonally multiplexed QAM sign does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Transmitter and receiver for an othogonally multiplexed QAM sign, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Transmitter and receiver for an othogonally multiplexed QAM sign will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2365229