System and a method for determining an image rejection characteristic of a receiver within a transceiver

Patent metadata

Field	Value
Publication number	US-10261193-B2
Application number	US-201615151796-A
Country	US
Kind code	B2
Filing date	May 11, 2016
Priority date	Jun 25, 2015
Publication date	Apr 16, 2019
Grant date	Apr 16, 2019

Abstract

A method for determining an image rejection characteristic of a receiver within a transceiver is provided. The transceiver uses a common local oscillator. The method includes generating a test signal having a spectral peak and generating a local oscillator signal comprising a frequency with an offset from a center frequency of the spectral peak. Further, the method includes down-mixing the test signal in the receiver using the local oscillator signal to generate a down-mixed signal. The method further includes calculating a first value of a signal characteristic of the down-mixed signal in a first frequency range corresponding to a desired signal component of the down-mixed signal and calculating a second value of the signal characteristic of the down-mixed signal in a second frequency range corresponding to an undesired signal component of the down-mixed signal. Further, the method includes comparing the first value and the second value to generate the image rejection characteristic.

First claim

What is claimed is:

1. A method for determining an image rejection characteristic of a receiver within a transceiver using a common local oscillator, comprising:
generating a test signal having a spectral peak;
generating a local oscillator signal comprising a frequency with an offset from a center frequency of the spectral peak;
down-mixing the test signal in the receiver using the local oscillator signal to generate a down-mixed signal;
calculating a first value of a signal characteristic of the down-mixed signal in a first frequency range corresponding to a desired signal component of the down-mixed signal;
calculating a second value of the signal characteristic of the down-mixed signal in a second frequency range corresponding to an undesired signal component of the down-mixed signal; and
comparing the first value and the second value to generate the image rejection characteristic.

2. The method of claim 1 , wherein a center frequency of the first frequency range has an offset from an intermediate frequency, and wherein the second frequency range is mirror-inverted to the first frequency range with respect to the intermediate frequency.

3. The method of claim 2 , wherein the intermediate frequency is zero.

4. The method of claim 1 , wherein the test signal omits another spectral peak being mirror-inverted to the spectral peak with respect to the frequency of the local oscillator signal.

5. The method of claim 4 , wherein the test signal comprises a plurality of equidistant spectral peaks.

6. The method of claim 1 , wherein the first value of the signal characteristic is related to an energy of the down-mixed signal in the first frequency range and the second value of the signal characteristic is related to an energy of the down-mixed signal in the second frequency range.

7. The method of claim 1 , wherein comparing the first value of the signal characteristic and the second value of the signal characteristic comprises calculating a ratio of the first value of the signal characteristic and the second value of the signal characteristic.

8. A method for determining an image rejection characteristic of a receiver within a transceiver using a common local oscillator, comprising:
generating a test signal having a spectral peak, a local oscillator signal comprising a frequency with an offset from a center frequency of the spectral peak and a second local oscillator signal comprising a frequency being mirror-inverted to the local oscillator signal with respect to the center frequency of the spectral peak;
down-mixing the test signal in the receiver using the local oscillator signal to generate a down-mixed signal and down-mixing the test signal in the receiver using the second local oscillator signal to generate a second down-mixed signal;
calculating a value of a signal characteristic of the down-mixed signal and a value of the signal characteristic of the second down-mixed signal in a frequency range corresponding to a desired signal component of the down-mixed signal; and
comparing the value of the signal characteristic of the down-mixed signal and the value of the signal characteristic of the second down-mixed signal to generate the image rejection characteristic.

9. The method of claim 8 , wherein the test signal omits another spectral peak being mirror-inverted to the spectral peak with respect to the frequency of the local oscillator signal, and wherein the test signal does not have another spectral peak being mirror-inverted to the spectral peak with respect to the frequency of second local oscillator signal.

10. The method of claim 9 , wherein the test signal comprises a plurality of equidistant spectral peaks.

11. The method of claim 8 , wherein the value of the signal characteristic of the down-mixed signal is related to an energy of the down-mixed signal in the frequency range and the value of the signal characteristic of the second down-mixed signal is related to an energy of the second down-mixed signal in the frequency range.

12. The method of claim 8 , wherein comparing the value of the signal characteristic of the down-mixed signal and the value of the signal characteristic of the second down-mixed signal comprises calculating a ratio of the value of the signal characteristic of the down-mixed signal and the value of the signal characteristic of the second down-mixed signal.

13. A system for determining an image rejection characteristic of a receiver within a transceiver using a common local oscillator, comprising:
a signal generator configured to generate a test signal having a spectral peak;
wherein the local oscillator is configured to generate a local oscillator signal comprising a frequency with an offset from a center frequency of the spectral peak, wherein the receiver is configured to down-mix the test signal using the local oscillator signal to generate a down-mixed signal, and
an analysis unit configured to calculate a first value of a signal characteristic of the down-mixed signal in a first frequency range corresponding to a desired signal component of the down-mixed signal, to calculate a second value of the signal characteristic of the down-mixed signal in a second frequency range corresponding to an undesired signal component of the down-mixed signal, and to compare the first value and the second value to generate the image rejection characteristic.

14. The system of claim 13 , wherein a center frequency of the first frequency range has an offset from an intermediate frequency, and wherein the second frequency range is mirror-inverted to the first frequency range with respect to the intermediate frequency.

15. The system of claim 14 , wherein the intermediate frequency is zero.

16. The system of claim 13 , wherein the test signal omits another spectral peak being mirror-inverted to the spectral peak with respect to the frequency of the local oscillator signal.

17. The system of claim 16 , wherein the test signal comprises a plurality of equidistant spectral peaks.

18. The system of claim 13 , wherein the first value of the signal characteristic is related to an energy of the down-mixed signal in the first frequency range and the second value of the signal characteristic is related to an energy of the down-mixed signal in the second frequency range.

19. The system of claim 13 , wherein the analysis unit is configured to compare the first value of the signal characteristic and the second value of the signal characteristic by calculating a ratio of the first value of the signal characteristic and the second value of the signal characteristic.

20. The system of claim 13 , wherein the signal generator comprises a frequency multiplier configured to generate the test signal by multiplying a frequency of a reference signal used for the local oscillator.

21. A system for determining an image rejection characteristic of a receiver within a transceiver using a common local oscillator, comprising:
a signal generator configured to generate a test signal having a spectral peak;
wherein the local oscillator is configured to generate a local oscillator signal comprising a frequency with an offset from a center frequency of the spectral peak and a second local oscillator signal comprising a frequency being mirror-inverted to the frequency of the local oscillator signal with respect to the center frequency of the spectral peak,
wherein the receiver is configured to down-mix the test signal using the local oscillator signal to generate a down-mixed signal and to down-mix the test sig

Assignees

• Intel Ip Corp

Inventors

• Kreienkamp Rainer Dirk
• Yan Junlin
• Doppke Harald
• Hammes Markus

Classifications

• G01S19/23 Primary

  Testing, monitoring, correcting or calibrating of receiver elements · CPC title