Receiver gain management
View Patent ↗Noise floor searching is performed for a cellular base station to increase accuracy of receiver gain estimates. This allows adjustment of gain in a radio module to account for gain in front-end devices, and achieve a desired overall receiver target gain. The gain of the RF front-end devices is estimated based on the difference between measured Rx noise power at a receive port of the radio module and the noise floor of the radio module. In one embodiment, frequency sweeping across a receive band using a narrowband filter is done to search for minimum noise power. Interference detection may also be employed to increase awareness of any interfering signals that are presented at a configured channel. It is determined whether the interference is wideband or narrowband.
1. A method of detecting interference, the method comprising:
setting a bandwidth for multiple receiver filters to a portion of a channel bandwidth that is a function of the number of such receiver filters;
merging the receiver filters to significantly cover the bandwidth of a channel;
moving the merged receiver filters to selected channels to identify whether interference is narrowband or wideband; and
increasing the receiver attenuation to protect the receiver from operating in the non-linear region and prevent an ADC (analog to digital converter) from saturation when a strong interfering signal is present.
2. The method of claim 1 wherein N received filters are used, and each covers approximately 1/N th of the bandwidth of the channel, where N can be any integer number.
3. The method of claim 1 wherein the channel is a CDMA channel having a bandwidth of approximately 1.23 MHz.
4. The method of claim 1 and further comprising measuring received power through each filter at the selected channels.
5. The method of claim 4 wherein the interference is identified as narrowband if the difference of received power across all filters is substantially large at a selected channel.
6. The method of claim 4 wherein the interference is identified as wideband if the difference of received power across all filters is small at a selected channel.
7. A micro-controller comprising:
means for setting a bandwidth for multiple receiver filters to a portion of a channel bandwidth that is a function of the number of such receiver filters;
means for merging the receiver filters to significantly cover the bandwidth of a channel; and
means for moving the merged receiver filters to selected channels to identify whether interference is narrowband or wideband.