Method and apparatus in a wireless communication device for mitigating a received power overload
View Patent ↗A power measurement element ( 106 ) measures ( 302 ) the wide-band received signal power of a receiver ( 102 ), and a wide-band AGC system ( 108 ) transfers ( 306 ) receiver gain control from an on-channel AGC system ( 110 ) to the wide-band AGC system, when the wide-band received signal power exceeds a pre-programmed threshold for longer than a pre-programmed delay time. The wide-band AGC system is arranged and programmed to decrease ( 308 ) a front-end gain of the receiver through a plurality of gain steps of a pre-programmed size ( 208 ) applied at a pre-programmed rate until the received wide-band signal power falls below the pre-programmed threshold.
1. A method in a wireless communication device having a receiver, the method for mitigating a received power overload by transferring control of a receiver gain from an on-channel AGC system to a wide-band AGC system, in response to a large increase in a wide-band received signal power, the method comprising the steps of:
measuring the wide-band received signal power;
transferring receiver gain control from the on-channel AGC system to the wide-band AGC system, when the wide-band received signal power exceeds a pre-programmed threshold for longer than a pre-programmed delay time; and
decreasing, by the wide-band AGC system after the transferring step, a front-end gain of the receiver through a plurality of gain steps of a pre-programmed size applied at a pre-programmed rate until the received wide-band signal power falls below the pre-programmed threshold.
2. The method of claim 1 , wherein the measuring step comprises the step of measuring the wide-band received signal power in an analog sum of squares detector.
3. The method of claim 1 , wherein the decreasing step comprises the step of decreasing the front-end gain of the receiver through a plurality of gain steps of a pre-programmed size applied at a pre-programmed rate that is substantially faster than an AGC update rate of the on-channel AGC system.
4. The method of claim 1 , further comprising the step of terminating the decreasing step when the front-end gain reaches a predetermined minimum value.
5. The method of claim 1 , further comprising, after the decreasing step has completed, the steps of:
returning receiver gain control to the on-channel AGC system; and
limiting, during a pre-programmed follow-up time period, changes in the front end gain of the receiver by the on-channel AGC system to a pre-programmed maximum gain change per AGC update.
6. The method of claim 5 , further comprising the steps of:
setting the delay time to a first pre-programmed value during the follow-up time period; and
setting the delay time to a second pre-programmed value at times outside of the follow-up time period.
7. An apparatus for use in a wireless communication device having a receiver, the apparatus for mitigating a received power overload by transferring control of a receiver gain from an on-channel AGC system to a wide-band AGC system, in response to a large increase in a wide-band received signal power, the apparatus comprising:
a power measurement element for measuring the wide-band received signal power;
the wide-band AGC system, coupled to the power measurement element, for transferring receiver gain control from the on-channel AGC system to the wide-band AGC system, when the wide-band received signal power exceeds a pre-programmed threshold for longer than a pre-programmed delay time; and
the on-channel AGC system, coupled to the wide-band AGC system for cooperating therewith to control the receiver gain,
wherein the wide-band AGC system is arranged and programmed to decrease a front-end gain of the receiver through a plurality of gain steps of a pre-programmed size applied at a pre-programmed rate until the received wide-band signal power falls below the pre-programmed threshold.
8. The apparatus of claim 7 , wherein the power measurement element comprises an analog sum of squares detector.
9. The apparatus of claim 7 , wherein the wide-band AGC system is further arranged and programmed to decrease the front-end gain of the receiver through a plurality of gain steps of a pre-programmed size applied at a pre-programmed rate that is substantially faster than an AGC update rate of the on-channel AGC system.
10. The apparatus of claim 7 , wherein the wide-band AGC system is further arranged and programmed to stop decreasing the front-end gain of the receiver when the front-end gain reaches a predetermined minimum value.
11. The apparatus of claim 7 , wherein the wide-band AGC system is further arranged and programmed to cooperate with the on-channel AGC system to return receiver gain control to the on-channel AGC system, and to limit, during a pre-programmed follow-up time period, changes in the front end gain of the receiver by the on-channel AGC system to a pre-programmed maximum gain change per AGC update.
12. The apparatus of claim 11 , wherein the wide-band AGC system is further arranged and programmed to set the delay time to a first pre-programmed value during the follow-up time period, and to set the delay time to a second pre-programmed value at times outside of the follow-up time period.
13. A wireless communication device, comprising:
a receiver for receiving a wireless communication signal; and
an apparatus coupled to the receiver for mitigating a received power overload by transferring control of a receiver gain from an on-channel AGC system to a wide-band AGC system, in response to a large increase in a wide-band received signal power, the apparatus comprising:
a power measurement element for measuring the wide-band received signal power;
the wide-band AGC system, coupled to the power measurement element, for transferring receiver gain control from the on-channel AGC system to the wide-band AGC system, when the wide-band received signal power exceeds a pre-programmed threshold for longer than a pre-programmed delay time; and
the on-channel AGC system, coupled to the wide-band AGC system for cooperating therewith to control the receiver gain,
wherein the wide-band AGC system is arranged and programmed to decrease a front-end gain of the receiver through a plurality of gain steps of a pre-programmed size applied at a pre-programmed rate until the received wide-band signal power falls below the pre-programmed threshold.
14. The wireless communication device of claim 13 , wherein the power measurement element comprises an analog sum of squares detector.
15. The wireless communication device of claim 13 , wherein the wide-band AGC system is further arranged and programmed to decrease the front-end gain of the receiver through a plurality of gain steps of a pre-programmed size applied at a pre-programmed rate that is substantially faster than an AGC update rate of the on-channel AGC system.
16. The wireless communication device of claim 13 , wherein the wide-band AGC system is further arranged and programmed to stop decreasing the front-end gain of the receiver when the front-end gain reaches a predetermined minimum value.
17. The wireless communication device of claim 13 , wherein the wide-band AGC system is further arranged and programmed to cooperate with the on-channel AGC system to return receiver gain control to the on-channel AGC system, and to limit, during a pre-programmed follow-up time period, changes in the front end gain of the receiver by the on-channel AGC system to a pre-programmed maximum gain change per AGC update.
18. The wireless communication device of claim 17 , wherein the wide-band AGC system is further arranged and programmed to set the delay time to a first pre-programmed value during the follow-up time period, and to set the delay time to a second pre-programmed value at times outside of the follow-up time period.