Receiver for a multimode radio

• US 7,515,929 B2
• Filed: 04/27/2005
• Issued: 04/07/2009
• Est. Priority Date: 04/27/2005
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Skyworks Solutions Incorporated
• Inventors: Lipan, Tudor, Beamish, Norman J, Vasa, John E., Ramachandran, Balasubramanian
• Primary Examiner(s): SHARMA, SUJATHA R
• Application Number:
  US11/116,086
• Publication Number:
  US 20060246942A1
• Time in Patent Office: 1,441 Days
• Field of Search: 455/422.1, 455/450, 455/456.1, 455/553.1, 455/550.1, 455/73, 455/78, 455/168.1, 455/240.1, 455/234.1, 455/239.1, 455/552.1, 455/245.1, 375/219, 375/232, 375/216, 375/229, 375/233, 375/316, 375/136, 375/141, 375/143, 375/152, 375/343, 375/148
• US Class Current: 455/550.1
• CPC Class Codes: H04B 1/0067 with one or more circuit blocks in common for different bands
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04B 2201/70711 with modular structure

Abstract

A receiver for a multi-mode wireless device is provided. The receiver has multiple analog RF front end modules, with each module supporting a different mode of operation. The receiver has a single digital backend module for generating a digital baseband signal. A controller selects one of the available RF modules to use, and the selected RF module provides an analog communication signal to the digital backend. Each available mode has an associated set of factors. When a particular mode is selected, the set of factors associated with the selected mode is provided to the digital backend. The digital backend uses these factors to adjust the processing characteristics of its components, such as its analog to digital converter, filters, and gain controller. In this way, the single digital backend is adaptable to the requirements of each of the available radio modes.

Claims

1. A communication receiver, comprising:

a plurality of analog RF (radio frequency) front end modules, each constructed to provide a respective analog communication signal;

a memory storing sets of factors, each set of factors being associated with one of the front end modules;

a control circuit arranged to select one of the plurality of front end modules and select the set of factors associated with that front end module;

a digital backend module arranged to receive the analog communication signal from the selected front end module and generate a digital baseband signal, the digital backend module having a digital automatic gain control (AGC); and

the digital backend module operating the steps of;

receiving the analog communication signal from the selected front end module;

using the selected set of factors associated with the selected front end module, including digital AGC coefficients, to digitally process the received analog communication signal, wherein the digital AGC receives a digital adjustment signal and a digital data signal, separates the digital adjustment signal into a coarse data and a fine data, adjusts the gain of the digital data signal according to the coarse data, and adjusts the gain of the digital data signal according to the fine data; and

generating a digital baseband signal.

2. The communication receiver according to claim 1, wherein the plurality of analog RF front end modules includes at least two modules selected from a group consisting of a CDMA module, a WCDMA module, a UMTS module, a GSM module, a PCS module, a cellular module, and a GPS module.

3. The communication receiver according to claim 1, wherein the digital backend module further includes an A/D (analog to digital) converter, and the A/D converter operates according to coefficients provided in the selected set of factors.

4. The communication receiver according to claim 1, wherein the digital backend module further includes a down-sampler, and the down-sampler operates according to coefficients provided in the selected set of factors.

5. The communication receiver according to claim 1, wherein the digital backend module further includes a channel filter, and the channel filter operates according to coefficients provided in the selected set of factors.

6. The communication receiver according to claim 1, wherein the digital AGC is constructed to implement a dB linear gain.

7. The communication receiver according to claim 6, wherein the digital AGC is constructed to implement a resolution of less than 0.2 dB.

8. The communication receiver according to claim 1, wherein the coarse data is integer data and the coarse data adjustment includes a bit shift process.

9. The communication receiver according to claim 1, wherein the fine data is fractional data and the fine data adjustment includes a multiplication process.

10. A method of generating a digital baseband signal, comprising:

providing a receiver having a plurality of analog RF (radio frequency) front end modules, each capable of providing a respective analog communication signal;

providing sets of predefined factors, each set of factors associated with one of the analog front end modules;

selecting a single one of the analog front end modules and its associated set of factors;

switching the analog communication signal from the selected analog front end module to a digital backend module, the digital backend module having a digital automatic gain control (AGC);

configuring the backend module using the selected set of factors, the selected set of factors including AGC coefficients for configuring the AGC, wherein the digital AGC receives a digital adjustment signal and a digital data signal, separates the digital adjustment signal into a coarse data and a fine data, adjusts the gain of the digital data signal according to the coarse data, and adjusts the gain of the digital data signal according to the fine data; and

generating the digital baseband signal according to the selected set of factors.

11. The method of generating a digital baseband signal according to claim 10, wherein the plurality of analog RF front end modules includes at least two modules selected from a group consisting of a CDMA module, a WCDMA module, a UMTS module, a GSM module, a PCS module, a cellular module, and a GPS module.

12. The method of generating a digital baseband signal according to claim 10, further including the step of operating an AID (analog to digital) convener according to coefficients provided in the selected set of factors.

13. The method of generating a digital baseband signal according to claim 10, further including the step of operating a down-sampler according to coefficients provided in the selected set of factors.

14. The method of generating a digital baseband signal according to claim 10, further including the step of operating a channel filter according to coefficients provided in the selected set of factors.

15. A communication receiver, comprising:

a first analog RF (radio frequency) front end module constructed to provide a first analog communication signal;

a second analog RF (radio frequency) front end module constructed to provide a second analog communication signal;

a control circuit arranged to select one of the analog front end modules;

a switch acting responsive to the control circuit, the switch configured to select the analog communication signal from the selected front end module;

a digital backend connected to the switch and arranged to receive the selected analog communication signal, the digital backend including a digital automatic gain control (AGC); and

the digital backend operating the steps of;

receiving the analog communication signal from the selected front end module;

digitally processing the received analog communication signal according to a first set of digital factors when the first analog front end module is selected, the first set of digital factors including AGC coefficients for configuring the AGC, wherein the digital AGC receives a digital adjustment signal and a digital data signal, separates the digital adjustment signal into a coarse data and a fine data, adjusts the gain of the digital data signal according to the coarse data, and adjusts the gain of the digital data signal according to the fine data;

digitally processing the received analog communication signal according to a second set of digital factors when the second analog front end module is selected, the second set of digital factors including AGC coefficients for configuring the AGC, wherein the digital AGC receives a digital adjustment signal and a digital data signal, separates the digital adjustment signal into a coarse data and a fine data, adjusts the gain of the digital data signal according to the coarse data, and adjusts the gain of the digital data signal according to the fine data; and

generating a digital baseband signal.

16. The communication receiver according to claim 15, wherein the first and second analog RF front end modules are each selected from a group consisting of a CDMA module, a WCDMA module, a UMTS module, a GSM module, a PCS module, a cellular module, and a GPS module.

17. The communication receiver according to claim 15, wherein the digital backend module further includes:

an A/D converter operating according to coefficients in the selected set of digital factors;

a down-sampler operating according to coefficients in the selected set of digital factors; and

a channel filter operating according to coefficients in the selected set of digital factors.

18. A communication receiver, comprising:

a plurality of analog RF (radio frequency) front end modules, each front end module constructed to provide a respective analog communication signal;

a digital backend arranged to selectively receive an analog communication signal from one of the front end modules, the digital backend including a digital automatic gain control (AGC); and

the digital backend operating the steps of;

digitally processing the received analog communication signal according to a set of digital factors associated with the selected front end module, the selected set of digital factors including AGC coefficients for configuring the AGC, wherein the digital AGC receives a digital adjustment signal and a digital data signal, separates the digital adjustment signal into a coarse data and a fine data, adjusts the gain of the digital data signal according to the coarse data, and adjusts the gain of the digital data signal according to the fine data; and

generating a digital baseband signal.

19. The communication receiver according to claim 18, wherein the analog RF front end modules are each selected from a group consisting of a CDMA module, a WCDMA module, a UMTS module, a GSM module, a PCS module, a cellular module, and a GPS module.