Method and apparatus for reducing or removing click noise

• US 8,855,252 B2
• Filed: 01/27/2012
• Issued: 10/07/2014
• Est. Priority Date: 02/10/2011
• Status: Active Grant

• Current Assignee: NXP B.V. (NXP Semiconductors NV)
• Original Assignee: NXP B.V. (NXP Semiconductors NV)
• Inventors: Siemons, Jasper, Groot Hulze, Gertjan
• Primary Examiner(s): Bayard, Emmanuel
• Application Number:
  US13/359,816
• Publication Number:
  US 20120207255A1
• Time in Patent Office: 984 Days
• Field of Search: 375284-285, 375/346, 375/350
• US Class Current: 375/346
• CPC Class Codes: H04B 1/1081 Reduction of multipath noise by equalising H04B7/005

Abstract

The invention relates to an apparatus and a method for detecting and correcting input signals regarding click noise, using a first detector unit and a second correction unit, the detector unit differentiates the input signal and extracts the noise signal and compares the sum of two noise samples with a threshold value and in case this sum exceeds the threshold value a click is observed, while the correction unit corrects the input signal in the phase domain and differentiates it prior to outputting the corrected signal.

Claims

1. A method for detecting and correcting click noise in input signals processed by an FM radio receiver, the method comprising:

differentiating, with a detector unit, first and second input phase signals;

extracting, with the detector unit, first and second noise signals;

comparing, with the detector unit, a sum of the first and second noise signals with a threshold value;

detecting, with the detector unit, the click noise when the sum exceeds the threshold value;

correcting, with the correction unit, the first input phase signal; and

outputting a differentiated version of the corrected phase signal.

2. A method according to claim 1, wherein the differentiation creates an MPX signal.

3. A method according to claim 1, wherein the extraction takes place in a block an subtracts a low pass filtered signal from a delayed signal.

4. A method according to claim 1, further comprising:

adding two consecutive noise signals to create a further signal;

comparing an absolute value of the further signal with a predetermined threshold value; and

detecting the clock noise when the absolute value exceeds the predetermined threshold value.

5. A method according to claim 1, further comprising:

correcting a predetermined number of phase signals after detecting the click noise.

6. A method according to claim 5, further comprising:

correcting three phase signals.

7. A method according to claim 1, wherein the method has been implemented within a digital signal processor.

8. An apparatus configured to reduce click noise in input phase signals processed by an FM radio receiver, the apparatus comprising:

a detector unit that is configured to differentiate the first and second input phase signals, extract first and second noise signals, compare a sum of the first and second noise signals with a threshold value, and detect the click noise when this sum exceeds the threshold value; and

a correction unit that is configured to correct the first input phase signal and output a differentiated version of the corrected phase signal.

9. An apparatus according to claim 8, wherein the click noise is removed.