Suppression of unwanted signal elements by sinusoidal amplitude windowing

• US 20050262178A1
• Filed: 11/19/2004
• Published: 11/24/2005
• Est. Priority Date: 11/21/2003
• Status: Active Grant

• Current Assignee: BAE Systems Plc
• Original Assignee: BAE Systems Plc
• Inventors: Richardson, Michael Richard
• Granted Patent: US 8,085,886 B2
• Time in Patent Office: Days
• US Class Current: 708/400
• CPC Class Codes: H01Q 3/267 Phased-array testing or checking devices
• CPC Class Codes: H04B 17/10 of transmitters
• CPC Class Codes: H04B 7/0837 using pre-detection combining H04B7/0868 takes precedence
• CPC Class Codes: H04J 3/0608 Detectors therefor, e.g. correlators, state machines
• CPC Class Codes: H04L 27/2624 by soft clipping
• CPC Class Codes: H04L 7/08 the synchronisation signals recurring cyclically

Abstract

A method is provided for processing a signal containing regular or quasi-regular elements of unwanted signal, the method comprising the steps of: establishing timing characteristics of the unwanted signal elements in a portion of said signal; generating a time domain window function using said established timing characteristics; and applying the generated window function to said signal portion to selectively reduce the amplitude of said unwanted signal elements relative to other elements of said signal. Preferably the method includes applying an algorithm to restore the positions and amplitudes of spectral peaks in a frequency domain representation of the windowed signal.

Claims

1. A method for processing a signal containing regular or quasi-regular elements of unwanted signal, the method comprising the steps of:

(i) establishing timing characteristics of the unwanted signal elements in a portion of said signal;

(ii) generating a time domain window function using said established timing characteristics; and

(iii) applying the generated window function to said signal portion to selectively reduce the amplitude of said unwanted signal elements relative to other elements of said signal.

2. A method according to claim 1, wherein said time domain window function is a sinusoidal function.

3. A method according to claim 1, further comprising the steps of:

(iv) applying a Fourier transform to the signal output from step (iii); and

(v) applying an algorithm to restore the shape of peaks in the transformed signal to an approximation of their form in the absence of said unwanted signal elements.

4. A method according to claim 2, wherein said sinusoidal window function is arranged to have a zero crossing substantially coinciding with the position of each unwanted signal element established at step (ii).