Fast signal detection process

A method for detecting presence of a valid signal, the method comprises:

• initializing gain settings of a receiver section;
• measuring received signal strength of a signal received by the receiver section to produce a first received signal strength indication (RSSI);
• adjusting the gain setting of the receiver section such that the first RSSI is a predetermined offset less than a signal strength threshold to produce a gain adjusted representation of the signal;
• measuring the received signal strength of the gain adjusted representation of the signal to produce a second RSSI;
• comparing the second RSSI with the signal strength threshold;
• performing a correlation of the gain adjusted representation of the signal with a predetermined signal;
• and
• when the comparing of the second RSSI with the signal strength threshold or the performing the correlation of the gain adjusted representation indicates detection of a possible signal, adjusting the gain settings of the receiver section based on dynamic range of the receiver section.

A method for detecting presence of a valid signal, the method comprises:

• determining a first received signal strength indication (RSSI) of an in-band spectrum of an incoming signal;
• adjusting gain setting of a receiver section based on the first RSSI to pre-signal detect level to produce adjusted gain setting;
• amplifying the incoming signal in accordance with the adjusted gain setting of the receiver section to produce an amplified incoming signal;
• determining a second RSSI of a wide band spectrum of the amplified incoming signal;
• comparing the second RSSI with the signal strength threshold;
• performing a correlation of the gain adjusted representation of the signal with a predetermined signal;
• and
• when the comparing of the second RSSI with the signal strength threshold or the performing the correlation of the gain adjusted representation indicates detection of a possible signal, adjusting the gain settings of the receiver section based on dynamic range of the receiver section.

A radio receiver comprises:

• radio frequency (RF) front end operably coupled to convert an RF signal into a low intermediate frequency (IF) signal, wherein gain of the RF front end is established based on a front end gain setting control signal;
• analog to digital converter operably coupled to convert the low IF signal into a digital low IF signal, wherein gain of the analog to digital converter is established based on an ADC gain setting control signal;
• first power measurement module operably coupled to measure received signal strength of the digital low IF signal to produce a first RSSI value;
• low pass filter operably coupled to filter the digital low IF signal to produce a digital filtered signal;
• second power measurement module operably coupled to measure received signal strength of the digital filtered signal to produce a second RSSI value;
• data detection module operable coupled to recapture data from the digital filtered signal when the digital filtered signal is a valid signal;
• automatic gain control module operably coupled to generate the front end gain setting control signal and the ADC gain setting control signal by:
• initializing the front end gain setting control signal and the ADC gain setting control signal;
• adjusting the front end gain setting control signal and the ADC gain setting control signal such that the first RSSI is a predetermined offset less than a signal strength threshold;
• when the second RSSI value drifts from the signal strength threshold less the predetermined offset, appending a second offset to the second RSSI value to compensate for the drifting of the second RSSI value to produce an adjusted second RSSI value such that the signal strength threshold less the adjusted second RSSI value substantially equals the predetermined offset;
• continuing appending an updated offset to the adjusted second RSSI value when the adjusted second RSSI value drifts from the signal strength threshold less the predetermined offset until a possible signal is detected;
• and
• when the digital filtered signal is determined to be the valid signal, adjusting the gain settings of the receiver section based on dynamic range of the receiver section.

A radio receiver comprises:

• radio frequency (RF) front end operably coupled to convert an RF signal into a low intermediate frequency (IF) signal, wherein gain of the RF front end is established based on a front end gain setting control signal;
• analog to digital converter operably coupled to convert the low IF signal into a digital low IF signal, wherein gain of the analog to digital converter is established based on an ADC gain setting control signal;
• first power measurement module operably coupled to measure received signal strength of the digital low IF signal to produce a first RSSI value;
• low pass filter operably coupled to filter the digital low IF signal to produce a digital filtered signal;
• second power measurement module operably coupled to measure received signal strength of the digital filtered signal to produce a second RSSI value;
• data detection module operable coupled to recapture data from the digital filtered signal when the digital filtered signal is a valid signal;
• correlation module operably coupled to determine possible validity of the digital filtered signal;
• automatic gain control module operably coupled to generate the front end gain setting control signal and the ADC gain setting control signal by:
• setting the front end gain control signal and the ADC control signal to initial settings;
• adjusting the front end gain control signal and the ADC control signal such that the first RSSI value is a predetermined offset less than a signal strength threshold to produce a gain adjusted representation of the signal;
• measuring the received signal strength of the gain adjusted representation of the signal to produce a second RSSI value;
• comparing the second RSSI value with the signal strength threshold;
• performing a correlation of the gain adjusted representation of the signal with a predetermined signal;
• and
• when the comparing of the second RSSI with the signal strength threshold or the correlation module indicates that the digital filtered signal is possibly valid, adjusting the gain settings of the receiver section based on dynamic range of the receiver section.

An apparatus for detecting presence of a valid signal, the apparatus comprises:

• processing module;
• and
• memory operably coupled to the processing module, wherein the memory includes operational instructions that cause the processing module to:
• determine a first received signal strength indication (RSSI) of an in-band spectrum of an incoming signal;
• adjust gain setting of a receiver section based on the first RSSI to pre-signal detect level to produce adjusted gain setting;
• amplify the incoming signal in accordance with the adjusted gain setting of the receiver section to produce an amplified incoming signal;
• determine a second RSSI of a wide band spectrum of the amplified incoming signal;
• compare the second RSSI with the signal strength threshold;
• perform a correlation of the gain adjusted representation of the signal with a predetermined signal;
• and
• when the comparing of the second RSSI with the signal strength threshold or the performing the correlation of the gain adjusted representation indicates detection of a possible signal, adjust the gain settings of the receiver section based on dynamic range of the receiver section.