Receiver for imbalanced carriers

Patent metadata

Field	Value
Publication number	US-9118439-B2
Application number	US-201213584292-A
Country	US
Kind code	B2
Filing date	Aug 13, 2012
Priority date	Apr 6, 2012
Publication date	Aug 25, 2015
Grant date	Aug 25, 2015

Abstract

Techniques for using one or multiple downconverters to receive multiple transmissions sent on multiple carriers are disclosed. In an exemplary design, an apparatus includes first and second downconverters. The first downconverter downconverts a first radio frequency (RF) signal when it is selected. The second downconverter downconverts a second RF signal when it is selected. Each of the first and second RF signals includes multiple transmissions sent on multiple carriers to a wireless device. The first downconverter is selected to perform downconversion for the multiple transmissions when at least one criterion is not met. The first and second downconverters are selected to perform downconversion for the multiple transmissions, based on different mixing frequencies, when the at least one criterion is met. The at least one criterion may relate to imbalance between the multiple carriers, received power of a received RF signal, etc.

First claim

What is claimed is:

1. An apparatus comprising:
a first downconverter configured to downconvert a first radio frequency (RF) signal comprising multiple transmissions sent on multiple carriers to a wireless device, the first downconverter being selected to perform downconversion of the multiple carriers when at least one criterion is not met; and
a second downconverter configured to downconvert a second RF signal comprising the multiple transmissions sent on the multiple carriers, the first and second downconverters being selected to perform downconversion of the multiple carriers to recover data sent to the wireless device based on different mixing frequencies when the at least one criterion is met.

2. The apparatus of claim 1 , further comprising:
a low noise amplifier (LNA) configured to amplify an input RF signal from an antenna and provide an amplified RF signal, the first and second RF signals being generated based on the amplified RF signal.

3. The apparatus of claim 1 , further comprising:
a first low noise amplifier (LNA) configured to amplify a first input RF signal from a first antenna and provide the first RF signal; and
a second LNA configured to amplify a second input RF signal from a second antenna and provide the second RF signal.

4. The apparatus of claim 1 , further comprising:
a first amplifier configured to generate the first RF signal based on a first variable gain; and
a second amplifier configured to generate the second RF signal based on a second variable gain.

5. The apparatus of claim 4 , the first variable gain being determined based on a received power level of at least one transmission among the multiple transmissions, and the second variable gain being determined based on a received power level of at least one other transmission among the multiple transmissions.

6. The apparatus of claim 1 , the multiple transmissions on the multiple carriers comprising a first transmission sent on a first carrier by a first base station to the wireless device and a second transmission sent on a second carrier by a second base station to the wireless device, the first base station being non co-located with the second base station.

7. The apparatus of claim 1 , the at least one criterion comprising a criterion that is met if received power of a received RF signal is greater than a threshold.

8. The apparatus of claim 1 , the multiple transmissions on the multiple carriers comprising a first transmission on a first carrier and a second transmission on a second carrier, and the at least one criterion comprising a criterion that is met if a difference between received power of the first transmission and received power of the second transmission is greater than a threshold.

9. The apparatus of claim 1 , the at least one criterion comprising a criterion that is met if received power of a first transmission on a first carrier exceeds received power of a second transmission on a second carrier by a threshold, the second transmission being one of the multiple transmissions sent to the wireless device.

10. The apparatus of claim 1 , the at least one criterion comprising a criterion that is met if wideband power for a band comprising the multiple carriers exceeds narrowband power for one or more carriers by a threshold.

11. The apparatus of claim 1 , a first mixing frequency for the first downconverter and
a second mixing frequency for the second downconverter being selected to avoid residual sideband (RSB) due to one or more interfering transmissions falling on the multiple carriers.

12. The apparatus of claim 1 , the multiple transmissions on the multiple carriers comprising a first transmission on a first carrier at a first frequency and a second transmission on a second carrier at a second frequency, and the first downconverter downconverting the first RF signal based on a first local oscillator (LO) signal at the first frequency and the second downconverter downconverting the second RF signal based on a second LO signal at the second frequency when the first and second downconverters are selected.

13. The apparatus of claim 1 , the multiple transmissions on the multiple carriers comprising two transmissions on two adjacent carriers centered at a first frequency and a third transmission on a third carrier at a second frequency, and the first downconverter downconverting the first RF signal based on a first local oscillator (LO) signal at the first frequency and the second downconverter downconverting the second RF signal based on a second LO signal at the second frequency when the first and second downconverters are selected.

14. A method comprising:
selecting a first downconverter to perform downconversion of multiple carriers for multiple transmissions sent on the multiple carriers to a wireless device when at least one criterion is not met; and
selecting the first downconverter and a second downconverter to perform downconversion of the multiple carriers to recover data sent to the wireless device for the multiple transmissions sent on the multiple carriers, based on different mixing frequencies, when the at least one criterion is met.

15. The method of claim 14 , the at least one criterion comprising a first criterion that is met if received power of a received radio frequency (RF) signal is greater than a first threshold, or a second criterion that is met if a difference between received powers of two of the multiple transmissions on two of the multiple carriers is greater than a second threshold, or a third criterion that is met if received power of an interfering transmission on a first carrier exceeds received power of a desired transmission on a second carrier by a third threshold, or a combination thereof.

16. The method of claim 14 , the multiple transmissions on the multiple carriers comprising a first transmission on a first carrier at a first frequency and a second transmission on a second carrier at a second frequency, the method further comprising:
controlling the first downconverter to downconvert the first RF signal based on a first local oscillator (LO) signal at the first frequency and the second downconverter to downconvert the second RF signal based on a second LO signal at the second frequency when the first and second downconverters are selected.

17. An apparatus comprising:
means for selecting a first downconverter to perform downconversion of multiple carriers for multiple transmissions sent on the multiple carriers to a wireless device when at least one criterion is not met; and
means for selecting the first downconverter and a second downconverter to perform downconversion of the multiple carriers to recover data sent to the wireless device for the multiple transmissions sent on the multiple carriers, based on different mixing frequencies, when the at least one criterion is met.

18. The apparatus of claim 17 , the at least one criterion comprising a first criterion that is met if received power of a received radio frequency (RF) signal is greater than a first threshold, or a second criterion that is met if a difference between received powers of two of the multiple transmissions on two of the multiple carriers is greater than a second threshold, or a third criterion that is met if received power of an interfering transmission on a first carrier exceeds received power of a desired transmission on a second carrier by a third threshold, or a combination thereof.

19. The apparatus of claim 17 , the multiple transmissions on the multiple carriers comprising a first transmission on a first carrier at a fir

Assignees

• Fernando Udara C
• Qualcomm Inc

Inventors

• Fernando Udara C

Classifications

• H04B1/30

  for homodyne or synchrodyne receivers (demodulator circuits H03D1/22) · CPC title

• H04L5/001 Primary

  the frequencies being arranged in component carriers · CPC title

• H04B2001/1072

  by tuning the receiver frequency · CPC title

• H04B1/1027

  assessing signal quality or detecting noise/interference for the received signal · CPC title

• H04L27/3863

  Compensation for quadrature error in the received signal · CPC title