INTERFERENCE CANCELLATION SYSTEM
First Claim
Patent Images
1. An interference cancellation system comprising:
- a source of a wanted signal subject to interference from a reference or other coherent signal;
means for sampling the wanted signal and interference;
means for chopping and interrupting the wanted signal and interference at a known rate;
means for sampling the interrupted signal plus interference;
means connected to said interrupted signal sampling means for detecting the interrupted signal synchronously with the sampled intErference signal;
means for deriving a control signal proportional to the level of the interference signal input to the receiver;
a pair of controllers responsive to the control signal from the last means for varying the amplitude of R.F. signals passed therethrough;
means for applying a sample of the reference signal to the input of both said controllers;
means for shifting the phase of the output of one of the controllers by a known phase angle Alpha ;
means for summing the output of the one controller with the phase shifted output of the second controller;
means for subtractively combining the said summed outputs with the wanted signal and interference; and
means for applying the output of said last means to the input of the receiver.
0 Assignments
0 Petitions
Accused Products
Abstract
This invention relates to radio communication systems and more particularly to systems for minimizing or eliminating interference in radio receivers. The invention is more particularly directed towards the elimination of interference in radio receivers from strong adjacent transmitters having signal levels several orders of magnitude stronger than the wanted signal. This system includes means for sampling the unwanted or interference signal and linearly processing it to develop a signal that is related to the incoming signal as a relatively time invariant ratio. The system includes means for adding the derived signal to the received signal to effectively cancel the interference signal.
56 Citations
2 Claims
-
1. An interference cancellation system comprising:
- a source of a wanted signal subject to interference from a reference or other coherent signal;
means for sampling the wanted signal and interference;
means for chopping and interrupting the wanted signal and interference at a known rate;
means for sampling the interrupted signal plus interference;
means connected to said interrupted signal sampling means for detecting the interrupted signal synchronously with the sampled intErference signal;
means for deriving a control signal proportional to the level of the interference signal input to the receiver;
a pair of controllers responsive to the control signal from the last means for varying the amplitude of R.F. signals passed therethrough;
means for applying a sample of the reference signal to the input of both said controllers;
means for shifting the phase of the output of one of the controllers by a known phase angle Alpha ;
means for summing the output of the one controller with the phase shifted output of the second controller;
means for subtractively combining the said summed outputs with the wanted signal and interference; and
means for applying the output of said last means to the input of the receiver.
- a source of a wanted signal subject to interference from a reference or other coherent signal;
-
2. The combination in accordance with claim 1 wherein the phase shift angle Alpha is in the order of 90*.
Specification
-
- Resources
Litigation Campaign Assessment
Thank you for your request. You will receive a custom alert email when the Litigation Campaign Assessment is available.
×
-
Current AssigneeRabindra N. Ghose, Walter A. Sauter
-
Original AssigneeRabindra N. Ghose, Walter A. Sauter
-
InventorsGhose, Rabindra N., Sauter, Walter A.
-
Primary Examiner(s)Safourek, Benedict V.
-
Application NumberUS04/799,781Time in Patent Office1,338 DaysField of Search325/15,21,22,23,24,65,67,363 343/5.1,80 333/17US Class Current455/79CPC Class CodesH04B 1/126 having multiple inputs, e.g...H04B 1/525 with means for reducing lea...
