Receiving a communication signal in a bandwidth then if the noise level is above a predetermined level adjusting the bandwidth to accurately measure noise

摘要

A method and apparatus for controlling incoming power to a receiver in a dual mode communication device. According to the method and apparatus, the received signal is simultaneously processed by two separate filters, one filter (214) to process the incoming desired communication signal and the other filter (216) to process the noise for power estimation. With the communication device operating in a first mode initial filtering 208 is attuned to the corresponding bandwidth. When the noise level reaches a predetermined level, the first bandwidth is adjusted to get a better estimate of the noise present. Preferably in response to high noise levels, the incoming gain to the receiver is adjusted accordingly. The invention finds particular application to a dual mode communication device, such as a mobile 'phone, receiving AMPS (analogue) and GSM (digital) signals where it mitigates the interference effects of strong adjacent signals which would otherwise cause saturation of baseband circuitry.