| CPC H04B 1/1027 (2013.01) [G06F 17/142 (2013.01); H03M 1/12 (2013.01); H04B 15/00 (2013.01); H04W 88/14 (2013.01); H03L 7/0802 (2013.01); H04B 2001/1045 (2013.01); H04B 2001/1063 (2013.01)] | 18 Claims |

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1. A noise reduction system for a digital receiver for reducing noise in signals received at the digital receiver, wherein the digital receiver includes a digital receiver input for receiving an analogue signal, analogue signal processing circuitry for processing the received analogue signal, and an output for providing the processed signal to a digital signal processor, wherein the noise reduction system is configured to reduce noise in the received analogue signal after receipt of the analogue signal at the digital receiver input and before the received analogue signal enters the digital signal processor, wherein the noise reduction system comprises:
a first component comprising:
an input arranged to receive the analogue signal;
a processor arranged to assess the received analogue signal and to identify one or more noise signals within the received analogue signal; and
an output arranged to output the results of the noise signal identification; and
a second component comprising:
an input arranged to receive the results of the noise signal identification from the first component; and
electronic circuitry arranged, in dependence on the results of the noise signal identification, to apply one or more counter-measures to the received analogue signal to produce a modified analogue signal, the modified analogue signal having a reduced level of noise compared to the received analogue signal,
wherein the noise reduction system is arranged to assess the effectiveness of the one or more counter-measures applied by the second component to determine whether any further counter-measures are required, and
wherein the electronic circuitry of the second component is configured to generate a replica noise signal corresponding to one of the identified noise signals, to adjust the replica noise signal so that it is substantially in anti-phase with the identified noise signal and to mix the adjusted replica noise signal with the incoming analogue signal to produce the modified analogue signal.
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