Dynamic transmitter calibration

Patent metadata

Field	Value
Publication number	US-9655069-B2
Application number	US-201113228547-A
Country	US
Kind code	B2
Filing date	Sep 9, 2011
Priority date	Sep 9, 2011
Publication date	May 16, 2017
Grant date	May 16, 2017

Abstract

A method includes generating an indicator of interference introduced by a transmitter into a spectrum of an output transmit signal outside a target channel of the transmitter. The indicator is generated based on the output transmit signal. The method includes adjusting a power level of the output transmit signal based on the indicator and a predetermined interference indicator level. The indicator may indicate a carrier-to-interference (C/I) ratio of the output transmit signal, and the adjusting comprises setting the power level of the output transmit signal to a maximum power level that maintains the C/I ratio of the output transmit signal above the predetermined interference indicator level. The output transmit signal may be based on a radio-frequency output of a power amplifier of the transmitter prior to transmission over a channel and the generating comprises generating a baseband version of the output transmit signal.

First claim

What is claimed is:

1. A method comprising:
generating an indicator of interference introduced by a transmitter into a spectrum of an output transmit signal prior to transmission over a transmission medium, the indicator being generated based on the output transmit signal prior to transmission; and
adjusting a power level of the output transmit signal prior to transmission based on the indicator and a predetermined interference indicator level,
wherein generating the indicator comprises:
generating an out-of-band energy estimate of energy outside a target frequency band of the output transmit signal prior to transmission;
generating an in-band energy estimate of energy inside the target frequency band in the output transmit signal prior to transmission; and
generating the indicator based on the out-of-band energy estimate and the in-band energy estimate, the indicator indicating a carrier-to-interference (C/I) ratio of the output transmit signal prior to transmission.

2. The method, as recited in claim 1 , wherein the output transmit signal prior to transmission is based on a radio-frequency output of a power amplifier of the transmitter prior to transmission over the transmission medium and the generating the indicator comprises:
feeding back the output transmit signal prior to transmission, the feeding back providing the output transmit signal from the transmitter of a communications unit to a receiver of the communications unit; and
generating a baseband version of the output transmit signal prior to transmission.

3. The method, as recited in claim 1 ,
wherein the adjusting comprises setting the power level of the output transmit signal prior to transmission to a maximum power level that maintains the C/I ratio of the output transmit signal prior to transmission above the predetermined interference indicator level.

4. The method, as recited in claim 1 , further comprising:
generating an indicator of adjacent channel interference,
wherein the adjusting comprises setting the power level of the output transmit signal prior to transmission to a maximum power level that maintains the C/I ratio of the output transmit signal prior to transmission above the predetermined interference indicator level and maintains the indicator of adjacent channel interference below a second predetermined interference indicator level.

5. The method, as recited in claim 1 ,
wherein the adjusting comprises increasing a gain of the transmitter to a maximum gain that maintains alternate adjacent channel interference below the predetermined interference indicator level.

6. The method, as recited in claim 1 , wherein adjusting the power of the transmit signal comprises adjusting a gain of the transmitter based on one or more of a predetermined transmitter characteristic constant, a predetermined carrier-to-interference ratio, a predetermined adjacent channel interference level, and a predetermined alternate adjacent channel interference level.

7. The method, as recited in claim 1 , wherein adjusting the power of the transmit signal comprises adjusting each gain of at least two of a power amplifier gain, an RF mixer gain, and a modulator gain of the transmitter and the adjusting includes determining a maximum gain of the transmitter that satisfies one or more of a predetermined carrier-to-interference ratio, a maximum adjacent channel interference level, and a maximum alternate adjacent channel interference level.

8. The method, as recited in claim 1 , wherein adjusting the power of the transmit signal comprises adjusting a gain of the transmitter based on a current value of the gain of the transmitter and a predetermined transmitter characteristic constant.

9. A method comprising:
generating an indicator of interference introduced by a transmitter into a spectrum of an output transmit signal prior to transmission over a transmission medium, the indicator being generated based on the output transmit signal prior to transmission; and
adjusting a power level of the output transmit signal prior to transmission based on the indicator and a predetermined interference indicator level,
wherein generating the indicator comprises:
filtering a version of the output transmit signal prior to transmission by a first filter to generate an in-band signal;
filtering a version of the output transmit signal prior to transmission by a second filter to generate an out-of-band signal; and
generating the indicator based on the in-band signal and the out-of-band signal, the indicator indicating a carrier-to-interference (C/I) ratio of the output transmit signal prior to transmission.

10. The method, as recited in claim 9 , wherein the out-of-band signal is based on energy at a guard band frequency of the output transmit signal prior to transmission.

11. The method, as recited in claim 9 , wherein the output transmit signal prior to transmission is based on a radio-frequency output of a power amplifier of the transmitter prior to transmission over the transmission medium and the generating the indicator comprises:
feeding back the output transmit signal prior to transmission, the feeding back providing the output transmit signal from the transmitter of a communications unit to a receiver of the communications unit; and
generating a baseband version of the output transmit signal prior to transmission.

12. The method, as recited in claim 9 ,
wherein the adjusting comprises setting the power level of the output transmit signal prior to transmission to a maximum power level that maintains the C/I ratio of the output transmit signal prior to transmission above the predetermined interference indicator level.

13. The method, as recited in claim 9 , further comprising:
generating an indicator of adjacent channel interference,
wherein the adjusting comprises setting the power level of the output transmit signal prior to transmission to a maximum power level that maintains the C/I ratio of the output transmit signal prior to transmission above the predetermined interference indicator level and maintains the indicator of adjacent channel interference below a second predetermined interference indicator level.

14. A method comprising:
generating an indicator of interference introduced by a transmitter into a spectrum of an output transmit signal prior to transmission over a transmission medium, the indicator being generated based on the output transmit signal prior to transmission; and
adjusting a power level of the output transmit signal prior to transmission based on the indicator and a predetermined interference indicator level,
wherein the indicator indicates a carrier-to-interference (C/I) ratio of the output transmit signal prior to transmission and the method further comprises:
generating a second indicator of interference based on the output transmit signal prior to transmission,
wherein adjusting the power level comprises adjusting the power level of the output transmit signal prior to transmission to be a maximum power that maintains the indicator of interference above the predetermined interference indicator level and maintains the second indicator of interference below a second predetermined interference indicator level, the indicator of interference being independent of transmitter gain and the second indicator of interference being dependent on transmitter gain.

15. The method, as recited in claim 14 , wherein generating the indicator comprises:
generating an out-of-band energy estimate of energy outside a target frequency band of the output transmit signal prior to transmission, wherein the indicator is further based on the out-of-ba

Assignees

• Kelton James Robert
• Cave Michael David
• Vixs Systems Inc

Inventors

• Kelton James Robert
• Cave Michael David

Classifications

• H04W52/52 Primary

  using AGC [Automatic Gain Control] circuits or amplifiers · CPC title

• H04W52/241

  taking into account channel quality metrics, e.g. SIR, SNR, CIR or Eb/lo · CPC title

• H04W52/367

  Power values between minimum and maximum limits, e.g. dynamic range · CPC title

• H04W52/243

  taking into account interferences · CPC title