TECHNIQUES FOR CONTROLLING OPERATION OF CONTROL LOOPS IN A RECEIVER

• US 20080039042A1
• Filed: 11/16/2006
• Published: 02/14/2008
• Est. Priority Date: 05/15/2006
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Ciccarelli, Steven, George, Brian, Lau, Soon-Seng, Raghupathy, Arun, Banister, Brian, Gudem, Prasad
• Granted Patent: US 8,781,426 B2
• Time in Patent Office: Days
• US Class Current: 455/234.1
• CPC Class Codes: H04B 1/109 by improving strong signal performance of the receiver when strong unwanted signals are present at the receiver input

Abstract

Techniques for controlling operation of control loops in a receiver are described. The operation of at least one control loop is modified in conjunction with a change in operating state, which may correspond to a change in linearity state, gain state, operating frequency, antenna configuration, etc. A change in linearity state may occur when jammers are detected and may cause bias current of analog circuit blocks to be adjusted. The at least one control loop to be modified may include a DC loop, an AGC loop, etc. The operation of a control loop may be modified by disabling the control loop or changing its time constant prior to changing operating state, waiting a predetermined amount of time to allow the receiver to settle, and enabling the control loop or restoring its time constant after waiting the predetermined amount of time.

Claims

1. An apparatus configured

to adjust bias current of at least one analog circuit block in a receiver, and

to modify operation of at least one control loop in conjunction with the adjustment of the bias current.

2. The apparatus of claim 1, wherein the at least one analog circuit block comprises a voltage controlled oscillator (VCO).

3. The apparatus of claim 1, and configured

to detect for jammers in a received signal, and

to adjust the bias current based on results of the detection for jammers.

4. The apparatus of claim 1, and configured

to increase the bias current when jammers are detected and

to decrease the bias current when jammers are not detected.

5. The apparatus of claim 1, and configured

to disable a control loop prior to the adjustment of the bias current, and

to enable the control loop after the adjustment of the bias current.

6. The apparatus of claim 5, and configured

to wait a predetermined amount of time after the adjustment of the bias current, and

to enable the control loop after waiting the predetermined amount of time.

7. The apparatus of claim 1, and configured

to increase a time constant of a control loop prior to the adjustment of the bias current, and

to restore the time constant of the control loop after the adjustment of the bias current.

8. The apparatus of claim 1, wherein the at least one control loop comprises a direct current (DC) loop, and wherein the apparatus is configured

to disable the DC loop or increase a time constant of the DC loop prior to the adjustment of the bias current, and

to enable the DC loop or restore the time constant of the DC loop after the adjustment of the bias current.

9. The apparatus of claim 1, wherein the at least one control loop comprises an automatic gain control (AGC) loop, and wherein the apparatus is configured

to disable the AGC loop or increase a time constant of the AGC loop prior to the adjustment of the bias current, and

to enable the AGC loop or restore the time constant of the AGC loop after the adjustment of the bias current.

10. The apparatus of claim 1, and configured

to determine, for a control loop, a value associated with the adjusted bias current, and

to apply the value to the control loop after the adjustment of the bias current.

11. The apparatus of claim 10, wherein the control loop is a direct current (DC) loop or a time tracking loop, and wherein the value is for a DC correction or delay.

12. The apparatus of claim 1, and configured

to disable discrete gain adjustment prior to the adjustment of the bias current, and

to enable discrete gain adjustment after the adjustment of the bias current.

13. The apparatus of claim 1, and configured

to adjust a filter along with the adjustment of the bias current, and

to modify a time tracking loop in conjunction with the adjustment of the filter.

27. The apparatus of claim 5, and configured to filter or accumulate, or integrate the jammer detector output before the adjustment of the bias current and to disable the control loop before the adjustment of the bias current.

28. The apparatus of claim 1, and configured to turn off branches of a filter to reduce current consumption without substantially effecting the impulse response or transfer function of the filter.

14. A method comprising:

adjusting bias current of at least one analog circuit block in a receiver; and

modifying operation of at least one control loop in conjunction with the adjustment of the bias current.

15. The method of claim 14, wherein the adjusting the bias current comprises

increasing the bias current when jammers are detected, and

decreasing the bias current when jammers are not detected.

16. The method of claim 14, wherein the modifying the operation of the at least one control loop comprises

disabling a control loop prior to the adjustment of the bias current, and

enabling the control loop after the adjustment of the bias current.

17. An apparatus comprising:

means for adjusting bias current of at least one analog circuit block in a receiver; and

means for modifying operation of at least one control loop in conjunction with the adjustment of the bias current.

18. The apparatus of claim 17, wherein the means for adjusting the bias current comprises

means for increasing the bias current when jammers are detected, and

means for decreasing the bias current when jammers are not detected.

19. The apparatus of claim 17, wherein the means for modifying the operation of the at least one control loop comprises

means for disabling a control loop prior to the adjustment of the bias current, and

means for enabling the control loop after the adjustment of the bias current.

20. An apparatus configured

to change operating state of a receiver, and

to modify operation of at least one control loop in conjunction with the change in operating state.

21. The apparatus of claim 20, wherein the change in operating state corresponds to a change in linearity state of the receiver.

22. The apparatus of claim 20, wherein the change in operating state corresponds to a change in gain state of the receiver.

23. The apparatus of claim 20, wherein the change in operating state corresponds to a change in antenna configuration.

24. The apparatus of claim 20, wherein the at least one control loop comprises at least one of a direct current (DC) loop, an automatic gain control (AGC) loop, a phase locked loop (PLL), an automatic frequency control (AFC) loop, a time tracking loop (TTL), and a frequency tracking loop (FTL).

25. The apparatus of claim 20, and configured

to disable a control loop prior to changing operating state,

to wait a predetermined amount of time after changing operating state, and

to enable the control loop after waiting the predetermined amount of time.

26. A wireless device configured

to detect for jammers in a received signal,

to change linearity state of a receiver based on results of the detection for jammers,

to disable a direct current (DC) loop prior to changing linearity state,

to disable an automatic gain control (AGC) loop prior to changing linearity state,

to enable the DC loop after changing linearity state, and

to enable the AGC loop after changing linearity state.