Time delay beamformer and method of time delay beamforming
AssigneeQinetiq Limited
InventorsPeter Richardson, Geoffrey Herbert
Life of this patent
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Abstract
A time delay beamformer comprises input channels, which have associated samplers arranged to sample inputs signal carried upon the input channels. The samplers sample the input channels at a number of points in time to produce a number of sampled signals. An adaptive processor receives each of the input signals and each of the sampled signals, and generates processed signals therefrom. Time delay devices introduce a steering time delay to the processed signals and a summer generates a beamformed output signal the delayed processed signals.
Claims30
A time delay beamformer comprising a plurality of input channels, each channel having associated sampling means arranged to sample an input signal carried upon the input channel at a plurality of points in time to produce a plurality of sampled signals;
- processing means arranged to receive said input signals and said sampled signals, or signals indicative of each of the input signals and each of the plurality of sampled signals, and arranged to generate processed signals therefrom;
- steering time delay means arranged to introduce a steering time delay to said processed signals, or to signals indicative of said processed signals to produce at least two delayed signals;
- and summation means arranged to generate a beamformed output signal from the delayed signals, or from signals derived from the delayed signals.
A method of time delay beamforming comprising the steps of:
- i) tapping input signals of a plurality of detected signal inputs at regular time intervals to produce a plurality of time delayed sampled signals;
- ii) processing input signals, or signals indicative of the input signal(s), and the time delayed sampled signals, or signals indicative of the sampled signals, to reject unwanted signal components therefrom, to produce processed signals, or at least one processed signal;
- iii) applying a steering time delays to the processed signal(s), or signal(s) indicative of the processed signal(s) to produce at least one delayed signal;
- and
- iv) generating a beamformed output from the delayed signal(s), or from a signal indicative of the delayed signal(s).
A method of reducing the computational load associated with beamforming comprising the steps of:
- i) generating an estimated covariance matrix from a plurality of time delay tapped input channels;
- ii) forming an adaptive weight vector for a space-time channel from a column of the inverse of the covariance matrix;
- iii) applying the adaptive weight vector to the space-time channel to form an interferance cancelled spatial channelp;
- and
- iv) applying a time delay to the spatial channel.
A method of increasing the resolution of a sideways sensing sensor array comprising the steps of:
- i) receiving a plurality of input channel signals;
- ii) tapping a plurality of time delayed, tapped, sampled signals from each of the input channels;
- and
- iii) applying space time adaptive processing to the plurality of input channel signals and sampled signals so preserve the linear relationship between Doppler frequency and angle of return.
Dependencies are inferred from the claim text.