Multiplex communications – Wide area network – Packet switching
Patent
1984-11-16
1985-06-11
Olms, Douglas W.
Multiplex communications
Wide area network
Packet switching
H04J 102
Patent
active
045233110
ABSTRACT:
The present invention relates to a technique for recovering each of an entire analog speech signal and a modulated data signal simultaneously received over a transmission channel such as a common analog telephone speech channel. In the received composite signal, the entire modulated data signal is multiplexed within the normal analog speech signal frequency band where the speech is present and its signal power density characteristic is at a low level. Separation of the speech and data signals at the receiver is effected by recovering the modulation carrier frequency and demodulating the received signal to recover the data signal. The data signal is then (a) remodulated with the recovered carrier, (b) modified to cancel phase jitter and frequency offset errors detected during the data demodulating process and (c) convolved with an arbitrary channel impulse response in an adaptive filter whose output signal is subtracted from the received composite data and speech signal to generate the recovered speech signal. To improve the recovered speech signal, a least mean square algorithm is used to update the arbitrary channel impulse response output signal of the adaptive filter.
REFERENCES:
patent: 3718767 (1973-02-01), Ellis
patent: 3824347 (1974-07-01), Sorber et al.
patent: 3875339 (1975-04-01), Gruen et al.
patent: 4238849 (1980-12-01), Gassmann
patent: 4280020 (1981-07-01), Schnurr
patent: 4313197 (1982-01-01), Maxemchuk
patent: 4346380 (1982-08-01), Monticelli et al.
patent: 4355401 (1982-10-01), Ikoma et al.
patent: 4379947 (1983-04-01), Warner
"Adaptive Noise Cancelling: Principles and Applications" by Widrow et al., Proceeding IEEE, vol. 63, No. 12, Dec. 1975, pp. 1692-1716.
"Speech and Data Transmission in ACS Telephone Channels" by Bukhviner, Telecomm. & Radio Eng., vol. 30/31; Jul. 1976, pp. 111-113.
"A New Generation of Speech Plus Data Multiplexer" Shum et al., Conf. on Communications and Equipment and Systems, Birmingham, England, Apr. 4-7, 1978, pp. 111-113.
"Frequency Domain Data Transmission Using Reduced Computational Complexity Algorithms" by Peled et al., ICASSP 80 Proc., Denver, Colo., vol. 1, Apr. 9-11, 1980, pp. 964-967.
"An Integrated Digital Subscribers Speech & Data Service" by L. J. Stagg et al., ICC '80 Conf. Rec., vol. 3, Seattle, Wash.; Jun. 8-12, 1980; pp. 39.6.1-39.6.6.
"Speech-Band Data Modems" by Adams; Electronics & Power, vol. 26, No. 9; Sep. 1980; pp. 733-736.
"Adaptive Equalization and Phase Tracking for Simultaneous Analog/Digital Data Transmission" by Lim et al., BSTJ, vol. 60, No. 9, pp. 2039-2063.
"Simultaneous Transmission of Speech and Data Using Code-Breaking Techniques" by Steele et al.; BSTJ, vol. 60, No. 9; Nov. 1981, pp. 2081-2105.
"Method for Superimposing Data on Amplitude-Modulated Signals", by Lockhart et al.; Electronics Letters, vol. 18, No. 9, Apr. 29, 1982; pp. 379-381.
"High-Speed Digital and Analog Parallel Transmission Technique Over a Single Telephone Channel" by Akashi et al.; IEEE Trans. on Communications; vol. COM-30, No. 5, May 1982, pp. 1213-1218.
Lee Edward A.
Shaw David G.
AT&T Bell Laboratories
Olms Douglas W.
Pfeifle Erwin W.
LandOfFree
Simultaneous transmission of speech and data over an analog chan does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Simultaneous transmission of speech and data over an analog chan, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Simultaneous transmission of speech and data over an analog chan will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1187365