Gain contol to optimize sensitivity and blocking performance
In one embodiment, a method includes: setting, via a controller of a receiver, a plurality of gain components of the receiver for a maximum gain setting for an automatic gain control (AGC) sensitivity (SENS) mode; receiving, in a controller of the receiver, an indication that a power level of an intermediate frequency (IF) signal measured at an output of an IF amplifier of the receiver exceeds a first threshold; and transitioning from an AGC SENS mode to an AGC adjacent channel interference (ACI) mode in response to the indication that the power level of the IF signal exceeds the first threshold.
1. A receiver comprising:
a low noise amplifier (LNA) to receive and amplify a radio frequency (RF) signal;
a mixer to downconvert the amplified RF signal to an intermediate frequency (IF) signal;
a programmable gain amplifier (PGA) coupled to the mixer to amplify the IF signal, the LNA, the mixer, and the PGA having a first controllable gain;
a filter coupled to the PGA to filter the amplified IF signal, the filter having a second controllable gain;
a digitizer coupled to the filter to digitize the filtered amplified IF signal to a digitized signal;
a first power detector coupled to an input of the LNA, the first power detector to output a first detection signal in response to the RF signal exceeding a first threshold;
a second power detector coupled to an output of the PGA, the second power detector to output a second detection signal in response to the amplified IF signal exceeding a second threshold; and
a controller to transition from an automatic gain control (AGC) sensitivity (SENS) mode to an AGC adjacent channel interference (ACI) mode in response to the second detection signal.
2. The receiver of claim 1 , wherein in the AGC ACI mode, the controller is to first back off the second controllable gain and thereafter back off the first controllable gain.
3. The receiver of claim 2 , further comprising at least one RF gain component coupled to an input of the LNA, the at least one RF gain component having a third controllable gain, wherein, after the back off of the first controllable gain, the controller is to back off the third controllable gain.
4. The receiver of claim 3 , wherein the controller is to thereafter remove the third controllable gain, and if a signal metric information exceeds a third threshold, the controller is to further adjust the first controllable gain.
5. The receiver of claim 2 , wherein in the AGC SENS mode, the controller is to first back off the second controllable gain and thereafter back off the first controllable gain.
6. The receiver of claim 1 , wherein in response to the first detection signal, the controller is to directly back off a gain of at least one RF gain component.
7. The receiver of claim 6 , wherein in response to the first detection signal, the controller is to directly back off the gain of the at least one RF gain component until the first detection signal indicates that the RF signal is less than the first threshold.
8. The receiver of claim 1 , wherein:
in the AGC SENS mode, the controller is to optimize the receiver for noise performance; and
in the AGC ACI mode, the controller is to optimize the receiver for linearity and headroom.
9. The receiver of claim 8 , wherein in the AGC SENS mode, the controller is to cause a maximum RF gain setting for at least the LNA.
10. The receiver of claim 9 , wherein in the AGC SENS mode, the controller is to cause the maximum RF gain setting for at least the LNA, unless a blocker signal is detected.
11. The receiver of claim 8 , further comprising a plurality of gain tables, wherein at least one first gain table is associated with the AGC SENS mode and at least one second gain table is associated with the AGC ACI mode.
12. A method comprising:
setting, via a controller of a receiver, a plurality of gain components of the receiver for a maximum gain setting for an automatic gain control (AGC) sensitivity (SENS) mode;
receiving, in a controller of the receiver, an indication that a power level of an amplified intermediate frequency (IF) signal measured at an output of an IF amplifier of the receiver exceeds a first threshold, the IF signal derived from a radio frequency (RF) signal received in the receiver; and
transitioning from the AGC SENS mode to an AGC adjacent channel interference (ACI) mode in response to the indication that the power level of the amplified IF signal exceeds the first threshold.
13. The method of claim 12 , further comprising dynamically adjusting a gain setting for one or more of the plurality of gain components of the receiver based on a received signal strength indication obtained from a digital processor of the receiver.
14. The method of claim 13 , wherein dynamically adjusting the gain setting for one or more of the plurality of gain components comprises:
dynamically adjusting the gain setting for the one or more of the plurality of gain components in a first order for the AGC SENS mode; and
dynamically adjusting the gain setting for the one or more of the plurality of gain components in a second order for the AGC ACI mode.
15. The method of claim 12 , further comprising adjusting a gain setting of a filter of the receiver, the filter coupled to an output of the IF amplifier, in response to the indication that the power level of the amplified IF signal exceeds the first threshold.
16. The method of claim 12 , further comprising:
receiving, in the controller of the receiver, an indication that a power level of the RF signal exceeds a second threshold; and
dynamically adjusting a gain setting for at least one RF gain component of the receiver in response to the indication that the power level of the RF signal exceeds the second threshold.
17. The method of claim 12 , further comprising:
in the AGC SENS mode, optimizing the receiver for noise performance; and
in the AGC ACI mode, optimizing the receiver for linearity.
18. A wireless device comprising:
an antenna to transmit a transmit radio frequency (RF) signal and to receive a receive RF signal; and
an integrated circuit (IC) coupled to the antenna, the IC comprising:
an attenuator controllable to attenuate the receive RF signal, the attenuator comprising a first gain control region;
a low noise amplifier (LNA) coupled to the attenuator, the LNA to receive and amplify the receive RF signal;
a mixer to downconvert the amplified receive RF signal to an intermediate frequency (IF) signal;
an IF amplifier coupled to the mixer to amplify the IF signal, the LNA, the mixer, and the IF amplifier comprising a second gain control region;
a filter coupled to the IF amplifier to filter the amplified IF signal, the filter comprising a third gain control region;
a digitizer coupled to the filter to digitize the filtered amplified IF signal to a digitized signal;
a digital signal processor (DSP) coupled to the digitizer, the DSP to process the digitized signal;
a first power detector coupled to an output of the attenuator, the first power detector to output a first detection signal in response to the receive RF signal output from the attenuator exceeding a first threshold;
a second power detector coupled to an output of the IF amplifier, the second power detector to output a second detection signal in response to the amplified IF signal exceeding a second threshold; and
a controller to transition from an automatic gain control (AGC) sensitivity (SENS) mode to an AGC adjacent channel interference (ACI) mode in response to the second detection signal.
19. The wireless device of claim 18 , further comprising a storage to store a plurality of gain tables, wherein at least one first gain table is associated with the AGC SENS mode and at least one second gain table is associated with the AGC ACI mode.
20. The wireless device of claim 18 , wherein the controller is to:
dynamically adjust the first gain control region, the second gain control region and the third gain control region in a first order for the AGC SENS mode; and
dynamically adjust the first gain control region, the second gain control region and the third gain control region in a second order for the AGC ACI mode.