An Improved Kalman Filter Excisor for Suppressing Narrowband Gaussian Noise Interference
DEFENCE RESEARCH ESTABLISHMENT OTTAWA (ONTARIO)
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This technical note presents an improved Kalman filter excisor for dealing with narrowband Gaussian noise. For this type of interference, both envelope and phase vary with time. Since the Kalman filter approach is close to optimum for interferers with constant or very slowly varying envelopes, performance for the narrowband Gaussian noise case will be significantly less than optimum. Ways and means of improving the performance by up to 5 dB are presented. These include the use of an alternate filtering approach to estimate the envelope to counter group delay effects, and phase-smoothing to suppress some of the additional noise caused by temporary loss of lock by the Kalman filter during those instants when the envelope changes sign.
- Radio Countermeasures
- Electricity and Magnetism