Wideband radar system utilizing adaptive interference canceler
First Claim
1. A wideband radar apparatus having improved interference suppression capability, said apparatus comprising:
- an array of antenna elements combined to form a plurality of primary and secondary channels;
transmitter means for transmitting a long pulse radio frequency signal having a wide bandwidth;
receiver means for receiving a swath echo signal from each of said plurality of primary and auxiliary channels and respectively producing intermediate frequency signals each having a total bandwidth less than said wide bandwidth of said long pulse radio frequency signal;
interference suppression means for effecting a multiplicity of adaptive interference suppressing adjustments to a swath echo signal in a selected one of said primary channels, said interference suppression means including a systolic array; and
processing means for processing swath echo signals received form said interference cancellation means.
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Abstract
A wideband radar apparatus is provided having improved interference suppression characteristics. The known time versus bandwidth characteristic of the transmitted pulse is utilized to effect intermediate frequency bandwidth reduction in received swath echo signals. During the interpulse period, basebanded swath echo signals are then subjected to a series of adaptive interference suppressing updates. The adaptive weight vector produced during each of these updates is then applied to the same data used to generate the weights. Preferably, adaptive weight generation is performed in a systolic array according to a QR decomposition algorithm.
38 Citations
15 Claims
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1. A wideband radar apparatus having improved interference suppression capability, said apparatus comprising:
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an array of antenna elements combined to form a plurality of primary and secondary channels; transmitter means for transmitting a long pulse radio frequency signal having a wide bandwidth; receiver means for receiving a swath echo signal from each of said plurality of primary and auxiliary channels and respectively producing intermediate frequency signals each having a total bandwidth less than said wide bandwidth of said long pulse radio frequency signal; interference suppression means for effecting a multiplicity of adaptive interference suppressing adjustments to a swath echo signal in a selected one of said primary channels, said interference suppression means including a systolic array; and processing means for processing swath echo signals received form said interference cancellation means. - View Dependent Claims (2, 3, 4, 5)
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6. An adaptive interference suppression device usable with an antenna array apparatus having a plurality of primary and secondary channels, said device comprising:
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data buffer means for collecting data windows over a multiplicity of subintervals of an interval a signal is received by said primary and secondary channels; means for selecting a main channel from said primary channels corresponding to a particular subinterval, wherein channels of said plurality of primary channels other than said main channel as well as all of said plurality of said secondary channels are auxiliary channels; adaptive weight generation means for receiving respective data windows corresponding to said respective subinterval from said main channel and said auxiliary channels and responsively producing a weight vector to minimize interference during said particular subinterval; means for respectively applying weights of said weight vector to auxiliary channel data windows corresponding to said particular subinterval; summing means for summing weighted auxiliary channel data windows corresponding to said particular subinterval; and means for subtracting an output of said summing means from a main channel data window corresponding to said particular subinterval. - View Dependent Claims (7, 8, 9, 10, 11)
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12. A method of suppressing interference present in an electromagnetic swath echo received over an interval of time by an antenna array combined to form a plurality of primary and secondary channels, said method comprising the steps of:
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(a) sampling swath echo signals in each of said plurality of primary and secondary channels over a subinterval of time less than said interval of time; (b) assembling respective windows of data sampled in each of said plurality of primary and secondary channels over said subinterval of time; (c) selecting a main channel from said primary channels; (d) producing a weight vector to minimize interference during said subinterval; (e) applying said weight vector to respective windows of data corresponding to channels other than said main channel; (f) summing together windows of data to which said weight vector has been applied; and
,(g) subtracting a sum of windows of data to which said weight vector has been applied from a window of data in said main channel. - View Dependent Claims (13, 14, 15)
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Specification