Power saving mode for receiver circuit blocks based on transmitter activity

• US 20050221790A1
• Filed: 11/17/2004
• Published: 10/06/2005
• Est. Priority Date: 04/05/2004
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Wu, Yue, Persico, Charles J., Aparin, Vladimir
• Granted Patent: US 7,283,851 B2
• Time in Patent Office: Days
• US Class Current: 455/343.200
• CPC Class Codes: H04B 1/109 by improving strong signal performance of the receiver when strong unwanted signals are present at the receiver input
• CPC Class Codes: H04B 1/1615 Switching on; Switching off, e.g. remotely battery saving circuits associated with selective call operation H04W52/00; details of power consumption reduction in a PLL, H03L7/0802, H03L7/14, H03L2207/08, H03L2207/18; muting amplifiers by gain control see H03G3/34
• CPC Class Codes: H04B 1/525 with means for reducing leakage of transmitter signal into the receiver
• CPC Class Codes: H04B 1/56 with provision for simultaneous communication in two directions
• CPC Class Codes: H04W 52/0254 detecting a user operation or a tactile contact or a motion of the device
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

To reduce power consumption, receiver circuit blocks within a wireless device are biased with less current whenever possible while still achieving the desired performance. The receiver circuit blocks may include a voltage controlled oscillator (VCO) that generates an oscillator signal used for frequency downconversion of a received signal from the forward link, a low noise amplifier (LNA) that amplifies the received signal, and a mixer that frequency downconverts the received signal. The VCO may be biased with less current if phase noise performance is less stringent, e.g., when (1) the wireless device is not transmitting on the reverse link, (2) a large amplitude jammer is not detected, and/or (3) the received signal level is sufficiently high. The bias currents of other receiver circuit blocks may also be adjusted based on transmitter activity, detected jammer, and/or received signal level.

Claims

1. A wireless apparatus in a wireless full-duplex communication system, comprising:

a voltage controlled oscillator (VCO) operable to generate an oscillator signal used for frequency downconversion of a signal received via a forward link, the VCO having an adjustable bias current; and

a processor operable to determine whether the wireless apparatus is transmitting on a reverse link and to adjust the bias current of the VCO based on whether the wireless apparatus is transmitting on the reverse link.

2. The apparatus of claim 1, wherein the processor is operable to select a high bias current for the VCO if the wireless apparatus is transmitting on the reverse link and to select a low bias current for the VCO if the wireless apparatus is not transmitting.

3. The apparatus of claim 1, wherein the processor is operable to adjust the bias current of the VCO proportional to transmit power used for transmitting on the reverse link.

4. The apparatus of claim 1, wherein the processor is further operable to determine whether a large interfering signal is detected on the forward link and to adjust the bias current of the VCO further based on whether the large interfering signal is detected.

5. The apparatus of claim 4, wherein the processor is operable to select a low bias current for the VCO if the large interfering signal is not detected.

6. The apparatus of claim 1, wherein the processor is further operable to determine a signal level of the signal received via the forward link and to adjust the bias current of the VCO further based on the received signal level.

7. The apparatus of claim 6, wherein the processor is operable to select a low bias current for the VCO if the received signal level is sufficiently high.

8. A wireless apparatus in a wireless full-duplex communication system, comprising:

means for determining whether the wireless apparatus is transmitting on a reverse link; and

means for adjusting bias current of a voltage controlled oscillator (VCO) based on whether the wireless apparatus is transmitting on the reverse link, wherein the VCO generates an oscillator signal used for frequency downconversion of a signal received via a forward link.

9. The apparatus of claim 8, wherein the means for adjusting the bias current of the VCO comprises

means for adjusting the bias current of the VCO lower if the wireless apparatus is not transmitting on the reverse link, and

means for adjusting the bias current of the VCO higher if the wireless apparatus is transmitting on the reverse link.

10. The apparatus of claim 8, further comprising:

means for determining whether a large interfering signal is detected on the forward link; and

means for adjusting the bias current of the VCO further based on whether the large interfering signal is detected.

11. The apparatus of claim 8, further comprising:

means for determining a signal level of the signal received via the forward link; and

means for adjusting the bias current of the VCO further based on the received signal level.

12. A method of adjusting bias current in a wireless apparatus, comprising:

determining whether the wireless apparatus is transmitting on a reverse link in a wireless full-duplex communication system; and

adjusting bias current of a voltage controlled oscillator (VCO) based on whether the wireless apparatus is transmitting on the reverse link, wherein the VCO generates an oscillator signal used for frequency downconversion of a signal received via a forward link.

13. An integrated circuit comprising:

a voltage controlled oscillator (VCO) operable to generate an oscillator signal used for frequency downconversion of a signal received via a forward link in a wireless full-duplex communication system; and

a first variable current source operative to provide an adjustable bias current for the VCO, the bias current of the VCO being adjusted based on at least one condition including whether a signal is being transmitted on a reverse link.

14. The integrated circuit of claim 13, wherein the first variable current source is operative to provide a high bias current for the VCO if a signal is being transmitted on the reverse link and to provide a low bias current for the VCO if a signal is not being transmitted on the reverse link.

15. The integrated circuit of claim 13, wherein the bias current provided by the first variable current source for the VCO is adjusted proportional to an amount of transmit power used for transmitting on the reverse link.

16. The integrated circuit of claim 13, further comprising:

a local oscillator (LO) generator operative to receive the oscillator signal from the VCO and to generate an LO signal used for the frequency downconversion, wherein bias current of the LO generator is adjusted based on whether a signal is being transmitted on the reverse link.

17. The integrated circuit of claim 13, further comprising:

a low noise amplifier (LNA) operative to amplify the signal received via the forward link with an adjustable gain.

18. The integrated circuit of claim 17, further comprising:

a second variable current source operative to provide an adjustable bias current for the LNA, the bias current of the LNA being adjusted based on whether a signal is being transmitted on the reverse link.

19. The integrated circuit of claim 17, wherein the bias current provided by the first variable current source for the VCO is further adjusted based on the gain of the LNA.

20. The integrated circuit of claim 13, further comprising:

a mixer operative to frequency downconvert the signal received via the forward link, wherein bias current of the mixer is adjusted based on whether a signal is being transmitted on the reverse link.

21. The integrated circuit of claim 13, wherein the VCO and the first variable current source are implemented with complementary metal oxide semiconductor (CMOS) circuits.

22. A wireless apparatus in a wireless full-duplex communication system, comprising:

a processor operable to determine at least one condition indicative of an operating environment for the wireless apparatus, the at least one condition including whether the wireless apparatus is transmitting on a reverse link; and

at least one receiver circuit block operable to process a signal received via a forward link, wherein each of the at least one receiver circuit block has an adjustable bias current that is set based on the at least one condition.

23. The apparatus of claim 22, wherein the at least one receiver circuit block includes a voltage controlled oscillator (VCO) operable to generate an oscillator signal used for frequency downconversion of the signal received via the forward link.

24. The apparatus of claim 22, wherein the at least one receiver circuit block includes a low noise amplifier (LNA) operable to amplify the signal received via the forward link.

25. The apparatus of claim 22, wherein the at least one receiver circuit block includes a mixer operable to frequency downconvert the signal received via the forward link.

26. The apparatus of claim 22, wherein the bias current for each of the at least one receiver circuit block is reduced if the wireless apparatus is not transmitting on the reverse link.

27. The apparatus of claim 22, wherein the at least one condition further includes whether a large interfering signal is detected on the forward link.

28. The apparatus of claim 27, wherein the bias current for each of the at least one receiver circuit block is reduced if the large interfering signal is not detected.

29. The apparatus of claim 22, wherein the at least one condition further includes whether signal level of the signal received via the forward link is sufficiently high.

30. The apparatus of claim 29, wherein the bias current for each of the at least one receiver circuit block is reduced if the received signal level is sufficiently high.