Patent ID: 7912436

Claim:
A method comprising: (a) determining that a signal of interest is not present in a received radio frequency signal at an input of a low noise amplifier; (b) measuring a wideband signal strength indication at an output of a mixer, the mixer coupled to receive an output of the low noise amplifier; (c) comparing the wideband signal strength indication to a first threshold value; (d) reducing gain of the low noise amplifier when the wideband signal strength indication exceeds the first threshold value, until the wideband signal strength indication no longer exceeds the first threshold value; (e) determining if the wideband signal strength indication exceeds a second threshold value; (f) measuring a narrowband signal strength indication after band pass filtering the output of the mixer, when the wideband signal strength indication exceeds the second threshold value; (g) comparing the narrowband signal strength indication to a third threshold value; (h) reducing the gain of the low noise amplifier by a predetermined amount when the narrowband signal strength indication exceeds the third threshold value; (i) determining if intermodulation interference is present by measuring the narrowband signal strength indication for a non-linear gain response after reducing the gain of the low noise amplifier by the predetermined amount; (j) determining if the gain of the low noise amplifier exceeds a first predetermined minimum, if intermodulation interference is detected; (k) repeating (f) through (j), provided the gain of the low noise amplifier exceeds the first predetermined minimum, to establish a gain setting for the low noise amplifier to operate the low noise amplifier within its linear region of operation in order to optimize a signal-to-interference ratio of the mixer for subsequent reception of the signal of interest, in which a combination of wideband signal strength indication and narrowband signal strength indication based gain adjustment of the low noise amplifier is employed to compensate for intermodulation interference.