Power dissipation reduction in wireless transceivers
Methods and circuits for reducing power dissipation in wireless transceivers and other electronic circuits and systems. Embodiments of the present invention use bias current reduction, impedance scaling, and gain changes either separately or in combination to reduce power dissipation. For example, bias currents are reduced in response to a need for reduced signal handling capability, impedances are scaled thus reducing required drive and other bias currents in response to a strong received signal, or gain is increased and impedances are scaled in response to a low received signal in the presence of no or weak interfering signals.
1. A system for power dissipation reduction in a wireless receiver of a battery powered portable wireless device, and a corresponding reduction in a drain on battery life of the battery powered portable wireless device, the system comprising:
the wireless receiver configured to receive a wireless signal having a desired signal and an interferer signal;
the wireless receiver comprising a plurality of circuits, wherein the plurality of circuits comprise a receiver signal path and at least a circuit configured to determine a signal level of the interferer signal and a signal level of the desired signal; and
wherein when the desired signal level is greater than the interferer signal level, and both the desired and interferer signal levels are greater than the a noise floor, an impedance affecting the receiver signal path is dynamically increased until the noise floor is greater than the interferer signal level but still less than the desired signal level, whereby one or more drive currents are reduced, thereby reducing power consumption.
2. The system of claim 1 , wherein the reduction of power consumption increases a time interval between required recharging of the battery.
3. A system for power dissipation reduction in a wireless receiver of a battery powered portable wireless device, and a corresponding reduction in a drain on battery life of the battery powered portable wireless device, the system comprising:
the wireless receiver configured to receive a wireless signal having a desired signal and an interferer signal;
the wireless receiver comprising a plurality of circuits, wherein the plurality of circuits comprise a receiver signal path and at least a circuit configured to determine a signal level of the interferer signal and a signal level of the desired signal; and
wherein when the desired signal level and the interferer signal level are both large, an impedance affecting the receiver signal path is dynamically increased causing the a noise floor to be increased, thereby reducing power consumption.
4. The system of claim 3 , wherein dynamically adjusting an impedance is done consistently with a maximum signal handling level.
5. The system of claim 3 , wherein the reduction of power consumption increases a time interval between required recharging of the battery.
6. A system for power dissipation reduction in a wireless receiver of a battery powered portable wireless device, and a corresponding reduction in a drain on battery life of the battery powered portable wireless device, the system comprising:
the wireless receiver configured to receive a wireless signal having a desired signal and an interferer signal;
wherein the wireless receiver comprises a plurality of circuits, wherein the plurality of circuits comprise a receiver signal path and at least a circuit configured to determine a signal level of the interferer signal and a signal level of the desired signal;
wherein a worst case condition exists when the signal level of the desired signal is low in presence of an interferer signal; and
wherein when the desired signal level is smaller than the interferer signal level but larger than the worst case condition, a bias affecting the receiver signal path is dynamically reduced causing the maximum signal handling level to be lowered, thereby reducing power consumption.
7. The system of claim 6 , wherein when the bias affecting the receiver signal path is dynamically reduced, the maximum signal handling level is caused to be lowered to below the interferer signal level, consistent with a noise floor.
8. The system of claim 6 , wherein the reduction of power consumption increases a time interval between required recharging of the battery.
9. The system of claim 6 , wherein the bias affecting the receiver signal path being dynamically reduced is caused at least in part by dynamically varying an impedance.
10. A system for power dissipation reduction in a wireless receiver of a battery powered portable wireless device, and a corresponding reduction in a drain on battery life of the battery powered portable wireless device, the system comprising:
the wireless receiver configured to receive a wireless signal having a desired signal and an interferer signal;
the wireless receiver comprising a plurality of circuits, wherein the plurality of circuits comprise a receiver signal path and at least a circuit configured to determine a signal level of the interferer signal and a signal level of the desired signal;
wherein a worst case condition exists when the signal level of the desired signal is low in presence of an interferer signal; and
wherein when the desired signal level is less than the interferer signal level but greater than the worst case condition and the desired signal levels is greater than a noise floor, an impedance affecting the receiver signal path is dynamically increased, raising the noise floor and causing one or more drive currents to be reduced, thereby reducing power consumption.
11. The system of claim 10 , wherein the reduction of power consumption increases a time interval between required recharging of the battery.