Telecommunications – Receiver or analog modulated signal frequency converter – Noise or interference elimination
Patent
1991-10-17
1994-04-26
Eisenzopf, Reinhard J.
Telecommunications
Receiver or analog modulated signal frequency converter
Noise or interference elimination
455295, 455307, H04B 110
Patent
active
053075170
ABSTRACT:
An improved adaptive notch filter for removing undesired cochannel FM interference includes in-phase and quadrature signal processing paths in which the undesired FM signal is translated to zero frequency, i.e. to DC. In each of the in-phase and quadrature phase signal paths, a first multiplier translates the input frequency spectrum in a dynamic manner so that the frequency of the undesired FM signal is always centered on DC. The undesired signal, now at DC, is filtered out by a high pass filter with a sharp rolloff. The output of the high pass filter is remultiplied in a second multiplier to translate the desired FM signal back to the original position in the frequency spectrum. In order to eliminate an unwanted difference frequency remodulation signal at the output of the second multiplier, the quadrature phase signal path performs a parallel operation on the same input signal, but with a quadrature phase (90 degree phase shift) control signal. The output the in-phase and quadrature signal processing circuits are combined in an adder circuit to cancel the unwanted difference frequency remodulation signal.
REFERENCES:
patent: 2903693 (1959-09-01), Ley
patent: 3035231 (1962-05-01), Neelands
patent: 3226646 (1965-12-01), Ludwig
patent: 3723883 (1973-03-01), Renner
patent: 3753123 (1973-08-01), Carpenter
patent: 3911366 (1975-10-01), Baghdady
patent: 3961262 (1976-06-01), Gassman
patent: 4027264 (1977-05-01), Gutleber
patent: 4053932 (1977-10-01), Yamaguti
patent: 4067013 (1978-01-01), Smith
patent: 4088955 (1978-05-01), Baghdady
patent: 4135159 (1979-01-01), Kubanoff
patent: 4249261 (1981-02-01), Qgita
patent: 4270223 (1991-05-01), Marston
patent: 4328591 (1991-05-01), Baghdaddy
patent: 4349919 (1982-09-01), Richardson
patent: 4453137 (1984-06-01), Rittenbach
patent: 4513249 (1985-04-01), Baghdady
patent: 4696055 (1987-09-01), Marshall
patent: 4739518 (1988-04-01), Bickley
patent: 4859958 (1989-08-01), Myers
Bar-Ness (IEEE Com Feb. 1984).
El-Samie (IEEE Com Jun. 1983).
Bouvier (IEEE Com Feb. 1978).
Sundresh (IEEE Com Dec. 1977).
Cassara (IEEE Com Jun. 1980).
"Plessey Groundsat common channel Repeater", Jane's Defence Review vol. 2 No. 3 1981 pp. 225-227.
Eisenzopf Reinhard J.
Jacobson Allan
Wisler Mark D.
LandOfFree
Adaptive notch filter for FM interference cancellation does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Adaptive notch filter for FM interference cancellation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Adaptive notch filter for FM interference cancellation will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1719479