Signal receiver and mobile communication device for isolating a desired signal that is susceptible to variations in signal power

• US 7,564,396 B2
• Filed: 10/11/2005
• Issued: 07/21/2009
• Est. Priority Date: 10/18/2004
• Status: Expired due to Fees

• Current Assignee: NXP B.V. (NXP Semiconductors NV)
• Original Assignee: NXP B.V. (NXP Semiconductors NV)
• Inventors: Van Veldhoven, Robert Henrikus Margaretha, Breems, Lucien Johannes
• Primary Examiner(s): Mai; Lam T
• Application Number:
  US11/577,499
• Publication Number:
  US 20080218392A1
• Time in Patent Office: 1,379 Days
• Field of Search: 341130-160
• US Class Current: 341/161
• CPC Class Codes: H03M 3/394 among different orders of the loop filter
• CPC Class Codes: H03M 3/424 the quantiser being a multiple bit one
• CPC Class Codes: H03M 3/452 with weighted feedforward summation, i.e. with feedforward paths from more than one filter stage to the quantiser input
• CPC Class Codes: H03M 3/462 Details relating to the decimation process decimation filters in general H03H17/0416, H03H17/0621

Abstract

A signal receiver processing circuit for isolating a desired signal from an analog input signal that is susceptible to variations in signal power, e.g. from a radio front end, includes a variable gain amplifier, an analog to digital converter, a digital signal processor, and a control unit. The analog to digital converter provides a digital signal to the digital signal processor. The digital signal processor includes a digital filter. The control unit adjusts a filtering accuracy of the analog to digital converter and/or the digital signal processor unit in dependence of a signal quality of the input signal.

Claims

1. Device for digitally processing an analog input signal for isolating a desired signal that is susceptible to variations in signal power, the device comprising

an analog to digital converter for converting the analog input signal to a digital signal to be processed,

a digital signal processor for digitally processing the digital signal from the analog to digital converter, the digital signal processor including a digital filter, and

a control unit for adjusting a filtering accuracy of at least one of the analog to digital converter and the digital signal processor unit in dependence of a signal quality of the input signal,

wherein the analog to digital converter includes a loop comprising a loop filter, and the control unit is arranged for adjusting the filtering accuracy of the loop filter, wherein the loop filter comprises a sequence of a number of loop units constituting a loop filter of a filtering order related to the number of loop units, and the control unit is arranged for adjusting the filtering accuracy of the loop filter by adjusting the filtering order by activating or deactivating at least one loop unit.

2. Device as claimed in claim 1, wherein the sequence of loop units comprises integrators and feed forward units, and the control unit is arranged to deactivate or activate at least one integrator and subsequently adapting at least one of the feed forward units.

3. Device as claimed in claim 1, wherein the analog to digital converter is a sigma-delta converter and the loop comprises an analog loop filter coupled to a quantizer.

4. Device as claimed in claim 1, wherein the control unit is arranged for adjusting the filtering accuracy by activating or deactivating at least one filter section in the digital filter in the digital signal processor.

5. Device as claimed in claim 4, wherein the digital filter has a number of sections and corresponding filtering coefficients, and the control unit is arranged for adjusting the filtering accuracy by adjusting the number of sections and/or a number of bits of the filter coefficients.

6. Device as claimed in claim 1, wherein the control unit is arranged for adjusting the filtering accuracy by adjusting a number of bits of words representing values of the digital signal to be processed in the digital filter.

7. Device as claimed in claim 1, wherein the control unit is arranged for detecting a signal power or an interference level as the signal quality of the input signal.

8. Communication device, the device comprising a device for digitally processing an analog input signal as claimed claim 1, and a receiving unit for providing the analog input signal.

9. Device for digitally processing an analog input signal for isolating a desired signal that is susceptible to variations in signal power, the device comprising

an analog to digital converter for converting the analog input signal to a digital signal to be processed,

a digital signal processor for digitally processing the digital signal from the analog to digital converter, the digital signal processor including a digital filter, and

a control unit for adjusting a filtering accuracy of at least one of the analog to digital converter and the digital signal processor unit in dependence of a signal quality of the input signal,

wherein the control unit is arranged for adjusting the filtering accuracy by activating or deactivating at least one filter section in the digital filter in the digital signal processor, wherein the digital filter has a number of sections and corresponding filtering coefficients, and the control unit is arranged for adjusting the filtering accuracy by adjusting the number of sections and/or a number of bits of the filter coefficients.

10. Device as claimed in claim 9, wherein the analog to digital converter includes a loop comprising a loop filter, and the control unit is arranged for adjusting the filtering accuracy of the loop filter.

11. Device as claimed in claim 10, wherein the loop filter comprises a sequence of a number of loop units constituting a loop filter of a filtering order related to the number of loop units, and the control unit is arranged for adjusting the filtering accuracy of the loop filter by adjusting the filtering order by activating or deactivating at least one loop unit.

12. Device as claimed in claim 11, wherein the sequence of loop units comprises integrators and feed forward units, and the control unit is arranged to deactivate or activate at least one integrator and subsequently adapting at least one of the feed forward units.

13. Device as claimed in claim 10, wherein the analog to digital converter is a sigma-delta converter and the loop comprises an analog loop filter coupled to a quantizer.

14. Device as claimed in claim 9, wherein the control unit is arranged for adjusting the filtering accuracy by adjusting a number of bits of words representing values of the digital signal to be processed in the digital filter.

15. Device as claimed in claim 9, wherein the control unit is arranged for detecting a signal power or an interference level as the signal quality of the input signal.

16. Communication device, the device comprising a device for digitally processing an analog input signal as claimed claim 9, and a receiving unit for providing the analog input signal.

17. Device for digitally processing an analog input signal for isolating a desired signal that is susceptible to variations in signal power, the device comprising

an analog to digital converter for converting the analog input signal to a digital signal to be processed,

a digital signal processor for digitally processing the digital signal from the analog to digital converter, the digital signal processor including a digital filter, wherein the digital filter is a finite response filter, and

a control unit for adjusting a filtering accuracy of at least one of the analog to digital converter and the digital signal processor unit in dependence of a signal quality of the input signal;

and

wherein the analog to digital converter includes a loop comprising a loop filter, and the control unit is arranged for adjusting the filtering accuracy of the loop filter, wherein the loop filter comprises a sequence of a number of loop units constituting a loop filter of a filtering order related to the number of loop units, and the control unit is arranged for adjusting the filtering accuracy of the loop filter by adjusting the filtering order by activating or deactivating at least one loop unit.

18. Device as claimed in claim 17, wherein the sequence of loop units comprises integrators and feed forward units, and the control unit is arranged to deactivate or activate at least one integrator and subsequently adapting at least one of the feed forward units.

19. Device as claimed in claim 17, wherein the control unit is arranged for adjusting the filtering accuracy by activating or deactivating at least one filter section in the digital filter in the digital signal processor, wherein the digital filter has a number of sections and corresponding filtering coefficients, and the control unit is arranged for adjusting the filtering accuracy by adjusting the number of sections and/or a number of bits of the filter coefficients.