REDUCING POWER CONSUMPTION BY TAKING ADVANTAGE OF SUPERIOR IN-CIRCUIT DUPLEXER PERFORMANCE

• US 20110299434A1
• Filed: 06/04/2010
• Published: 12/08/2011
• Est. Priority Date: 06/04/2010
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Gudem, Prasad S., Lau, Soon-Seng, Liu, Li
• Granted Patent: US 8,842,582 B2
• Time in Patent Office: Days
• US Class Current: 370/278
• 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 1/525 with means for reducing leakage of transmitter signal into the receiver
• CPC Class Codes: H04W 52/0238 where the received signal is an unwanted signal, e.g. interference or idle signal
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Although the duplexer in a full-duplex transceiver circuit may only be guaranteed by the duplexer manufacturer to have a transmit band rejection from its TX port to its RX port of a certain amount, and may only be guaranteed to have a receive band rejection of another amount, the actual transmit band rejection and the actual receive band rejection of a particular instance of the duplexer may be better than specified. Rather than consuming excess power in the receiver and/or transmitter in order to meet performance requirements assuming the duplexer only performs as well as specified, the duplexer'"'"'s in-circuit performance is measured as part of a transmitter-to-receiver isolation determination. Transmitter and/or receiver power settings are reduced where possible to take advantage of the measured better-than-specified in-circuit duplexer performance, while still meeting transceiver performance requirements. Power settings are not changed during normal transmit and receive mode operation.

Claims

1. A method comprising:

(a) determining a transmitter-to-receiver isolation parameter, wherein the determining of (a) involves communicating a signal in a signal path from an output of a transmitter to an input of a receiver, wherein the transmitter and the receiver are parts of a transceiver, wherein (a) further involves taking a measurement of the signal, and wherein the transmitter-to-receiver isolation parameter is determined in (a) based at least in part on the measurement; and

(b) based on the transmitter-to-receiver isolation parameter determined in (a) setting a power consumption setting of a portion of the transceiver.

2. The method of claim 1, wherein the transmitter-to-receiver isolation parameter is taken from the group consisting of:

a transmit band rejection of the signal path from the output of the transmitter to the input of the receiver, a transmit band leakage power on the input of the receiver when the transmitter is transmitting in a transmit band at a maximum permissible output power, a receive band attenuation of the signal path from the output of the transmitter to the input of the receiver, and a receive band noise on the input of the receiver when the transmitter is transmitting in the transmit band at the maximum permissible output power.

3. The method of claim 1, wherein the portion is taken from the group consisting of:

circuitry in a transmit signal path within the transmitter, a transmitter local oscillator within the transmitter, circuitry in a signal path of a transmitter local oscillator signal from the transmitter local oscillator to a mixer of the transmitter, circuitry in a receive signal path within the receiver, a receiver local oscillator within the receiver, and circuitry in a signal path of a receiver local oscillator signal from the receiver local oscillator to a mixer of the receiver.

4. The method of claim 1, further comprising:

(c) using the receiver and the transmitter to engage in a full-duplex cellular telephone communication.

5. The method of claim 1, wherein (a) and (b) are repeated for each of a plurality of channels thereby generating corresponding plurality of power consumption settings for the portion of the transceiver.

6. The method of claim 1, wherein the transmitter-to-receiver isolation parameter determined in (a) is a transmit band leakage power, wherein the transmit band leakage power is determined by causing the receiver to receive in a transmit band, and wherein the transmit band is a transmit band used by the transceiver to engage in a full-duplex cellular telephone communication.

7. The method of claim 1, wherein the transmitter-to-receiver isolation parameter determined in (a) is a receive band attenuation, wherein the receive band attenuation is determined by causing the transmitter to transmit in a receive band, and wherein the receive band is a receive band used by the transceiver to engage in a full-duplex cellular telephone communication.

8. The method of claim 1, wherein the transmitter-to-receiver isolation parameter determined in (a) is a receive band noise, wherein the receive band noise is determined based in part on an output of a power detector and based in part on a determined receive band rejection of circuitry in the signal path.

9. The method of claim 1, wherein the transmitter and the receiver are parts of an integrated circuit, and wherein (a) involves communicating a signal in the signal path from the output of the transmitter, out of the integrated circuit, back into the integrated circuit, and to the input of the receiver.

10. An apparatus comprising:

a receiver;

a transmitter that outputs a signal that passes in a signal path from an output of the transmitter to an input of the receiver; and

a circuit that determines a transmitter-to-receiver isolation parameter based at least in part on a measurement of the signal, wherein the circuit sets a power consumption setting of a portion of the apparatus based on the determined transmitter-to-receiver isolation parameter.

11. The apparatus of claim 10, wherein the apparatus is a Radio Frequency (RF) transceiver adapted to engage in a full-duplex cellular telephone communication using the transmitter and the receiver, and wherein the circuit leaves the power consumption setting substantially unchanged during the full-duplex cellular telephone communication.

12. The apparatus of claim 10, wherein the transmitter-to-receiver isolation parameter is indicative of a characteristic of the signal path.

13. The apparatus of claim 10, wherein the transmitter-to-receiver isolation parameter is indicative of a characteristic of the signal path and is taken from the group consisting of:

a transmit band rejection, a transmit band leakage power, a receive band attenuation, and a receive band noise.

14. The apparatus of claim 10, wherein the portion is taken from the group consisting of:

circuitry in a transmit signal path within the transmitter, a transmitter local oscillator within the transmitter, circuitry in a signal path of a transmitter local oscillator signal from the transmitter local oscillator to a mixer of the transmitter, circuitry in a receive signal path within the receiver, a receiver local oscillator within the receiver, and circuitry in a signal path of a receiver local oscillator signal from the receiver local oscillator to a mixer of the receiver.

15. The apparatus of claim 10, wherein the circuit includes a processor that executes a set of processor-executable instructions.

16. The apparatus of claim 10, wherein the circuit determines a plurality of transmitter-to-receiver isolation parameter values, and wherein there is a one-to-one correspondence between the determined plurality of transmitter-to-receiver isolation parameter values and a corresponding plurality of channels of a transmit band.

17. A set of full-duplex transceivers that all share a substantially identical hardware circuit design, wherein each transceiver is operable in a plurality of channels of a transmit band, has a transceiver power consumption, and exhibits a transceiver power consumption versus channel pattern, wherein the transceivers fall into transceiver categories based on their transceiver power consumption versus channel patterns, wherein each of the transceivers includes a duplexer, wherein each duplexer has a transmitter-to-receiver isolation performance, wherein the duplexers fall into duplexer categories based on their transmitter-to-receiver isolation performances, and wherein all transceivers in a transceiver category include duplexers that are in the same duplexer category.

18. The set of full-duplex transceivers of claim 17, wherein the transmitter-to-receiver isolation performance of a duplexer is an attenuation between a transmit port of the duplexer and a receive port of the duplexer.

19. The set of full-duplex transceivers of claim 17, wherein there are full-duplex transceivers of the set that have duplexers having relatively higher transmit band rejection and receive band rejection, wherein there are full-duplex transceivers of the set that have duplexers having relatively lower transmit band rejection and receive band rejection, wherein substantially all the full-duplex transceivers that have duplexers having the relatively higher transmit band rejection and receive band rejection also have a lower average power consumption, whereas substantially all the full-duplex transceivers that have duplexers having the relatively lower transmit band rejection and receive band rejection also have a higher average power consumption.

20. A method comprising:

(a) tuning a transmitter to output a signal in a transmit band;

(b) tuning a receiver to receive in the transmit band;

(c) using the receiver to determine a transmit band leakage power at an input of the receiver in the transmit band; and

(d) if the determined transmit band leakage power is below a predetermined amount then using a lower power setting for the receiver whereas if the determined transmit band leakage power is above the predetermined amount then using a higher power setting for the receiver.

21. The method of claim 20, wherein (c) involves:

obtaining a receive power reading; and

using a receiver gain value and the receive power reading to determine the transmit band leakage power at the input of the receiver.

22. The method of claim 20, further comprising:

(e) using the transmitter and the receiver to engage in a W-CDMA communication.

23. The method of claim 20, wherein (b) occurs before (a).

24. The method of claim 20, wherein the transmitter and the receiver are parts of a full-duplex transceiver integrated circuit.

25. The method of claim 20, wherein (d) involves setting a Voltage Controlled Oscillator (VCO) within the receiver to consume a smaller amount of current if the determination in (d) is that the transmit band leakage power is below the predetermined amount, and wherein (d) involves setting the VCO to consume a larger amount of current if the determination in (d) is that the transmit band leakage power is above the predetermined amount.

26. The method of claim 20, wherein a portion of the signal output by the transmitter in (a) passes through a duplexer and is then received by the receiver in (b), and wherein the transmit band leakage power determined in (c) is a value indicative of a power of the portion of the signal that passed through the duplexer.

27. The method of claim 20, wherein the transmitter is tuned to output the signal at a transmit frequency in (a), and wherein (a) through (d) are repeated multiple times, wherein in each of these multiple times when (a) through (d) are repeated a different transmit frequency is used.

28. The method of claim 20, wherein the transmitter is tuned in (a) to output the signal at a transmit frequency, and wherein the receiver is tuned in (b) to receive at the transmit frequency.

29. The method of claim 20, wherein the transmitter is tuned in (a) to output the signal at a transmit frequency, and wherein the receiver is tuned in (b) to receive at a frequency that has an offset with respect to the transmit frequency.

30. The method of claim 20, wherein the lower power setting involves supplying a portion of the receiver with a lower supply current whereas the higher power setting involves supplying the portion of the receiver with a higher supply current.

31. The method of claim 20, wherein the lower power setting involves supplying a portion of the receiver with a lower supply voltage whereas the higher power setting involves supplying the portion of the receiver with a higher supply voltage.

32. An apparatus comprising:

a transmitter configured to output a signal in a transmit band;

a receiver tuned to receive in the transmit band such that the receiver receives the signal output by the transmitter and generates a receive power reading indicative of a power of the signal as received by the receiver; and

a processor configured to determine a transmit band leakage power at an input of the receiver in the transmit band based at least in part on the receive power reading, wherein if the determined transmit band leakage power is below a predetermined amount then the processor causes the receiver to be set to use a lower power setting whereas if the determined transmit band leakage power is above the predetermined amount then the processor causes the receiver to be set to use a higher power setting.

33. The apparatus of claim 32, wherein the processor determines the transmit band leakage power based in part on the receive power reading and on a receiver gain value.

34. The apparatus of claim 32, wherein the transmitter outputs the signal in the transmit band at a maximum permissible transmit output power.

35. The apparatus of claim 32, wherein the transmitter and the receiver are parts of a W-CDMA full-duplex transceiver integrated circuit.

36. An apparatus comprising:

a transmitter;

a receiver; and

means for determining a transmit band leakage power of a signal output by the transmitter in a transmit band and received on an input of the receiver, wherein the means is for determining the transmit band leakage power based at least in part on a receive power reading indicative of a power of the signal as received on the input of the receiver, wherein if the determined transmit band leakage power is below a predetermined amount then the means causes the receiver to be set to use a lower power setting whereas if the determined transmit band leakage power is above the predetermined amount then the means causes the receiver to be set to use a higher power setting.

37. The apparatus of claim 36, wherein the signal output by the transmitter is output at a maximum permissible transmit output power.

38. The apparatus of claim 36, wherein the means is for determining the power of the signal as received on the input of the receiver by adjusting the receive power reading using a receiver gain value.

39. The apparatus of claim 36, wherein the transmit band is a band used by the apparatus to engage in a W-CDMA full-duplex communication.

40. A processor-readable medium storing a set of processor-executable instructions, wherein execution of the set of processor-executable instructions by a processor is for:

causing a transmitter to be tuned to output a signal in a transmit band;

causing a receiver to be tuned to the transmit band such that the receiver receives the signal output by the transmitter and generates a receive power reading indicative of a power of the signal as received by the receiver; and

determining a transmit band leakage power at an input of the receiver in the transmit band based at least in part on the receive power reading, wherein if the determined transmit band leakage power is below a predetermined amount then the receiver is set to use a lower power setting whereas if the determined transmit band leakage power is above the predetermined amount then the receiver is set to use a higher power setting.