Method and apparatus for compensating for variations in a receive portion of a wireless communication device

• US 20040013083A1
• Filed: 04/24/2002
• Published: 01/22/2004
• Est. Priority Date: 04/24/2002
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Powell, Clinton C., Rahman, Mahibur, Sobchak, Charles Leroy
• Granted Patent: US 7,385,913 B2
• Time in Patent Office: Days
• US Class Current: 370/203
• CPC Class Codes: H04L 2025/0377 during the reception of training signals
• CPC Class Codes: H04L 25/03133 with a non-recursive structure H04L25/03127 takes precedence

Abstract

A generator (304) generates first and second training signals (320, 318) that originate within a wireless communication device (FIG. 3) instead of being received from a source outside the device. A receive portion (212, 214, 216) of the device processes the first training signal to derive a processed training signal. An adaptive equalizer (310) equalizes the processed training signal to derive an equalized training signal. A processor (312) compares the equalized training signal and the second training signal using an adaptive algorithm to derive coefficients for the adaptive equalizer to compensate for variations in the receive portion, and adjusts the adaptive equalizer in accordance with the coefficients to derive a compensated output signal.

Claims

1. A method for compensating for variations in a receive portion of a wireless communication device including at least one of a receiver and a transceiver, the method comprising in the device the steps of:

generating first and second training signals that originate within the device instead of being received from a source outside the device;

processing said first training signal through said receive portion to derive a processed training signal;

equalizing said processed training signal in an adaptive equalizer to derive an equalized training signal;

comparing said equalized training signal and said second training signal using an adaptive algorithm for deriving coefficients for said adaptive equalizer to compensate for the variations in said receive portion; and

adjusting said adaptive equalizer in accordance with said coefficients to derive a compensated output signal.

2. The method of claim 1, wherein the generating step comprises the step of generating a pseudo-random PN sequence within said device.

3. The method of claim 1,

wherein the generating, processing, equalizing, comparing, and adjusting steps are performed as part of a receiver warm-up sequence, and

wherein the method further comprises the step of holding constant the coefficients for said adaptive equalizer after said receiver warm-up sequence and during normal data reception.

4. The method of claim 1, wherein the processing step comprises the step of inserting said first training signal into an analog section of said receive portion.

5. The method of claim 4, wherein the processing step comprises the step of inserting said first training signal into a feedback path of a DC offset correction loop of said analog section.

6. The method of claim 1, wherein the generating step comprises the steps of:

generating said first training signal; and

processing said first training signal through a desired target receive filter to derive said second training signal.

7. The method of claim 6, wherein the adjusting step comprises the step of adjusting a response of a path through both said receive portion and said adaptive equalizer to match the response through said desired target receive filter.

8. The method of claim 1, wherein the generating step comprises the step of generating said first and second training signals such that said first and second training signals are identical to one another.

9. The method of claim 8, wherein the adjusting step comprises the step of adjusting said adaptive equalizer to maintain a response substantially equal to an inverse of the response of said receive portion.

10. An apparatus for compensating for variations in a receive portion of a wireless communication device including at least one of a receiver and a transceiver, the apparatus comprising:

a generator for generating first and second training signals that originate within the device instead of being received from a source outside the device;

said receive portion coupled to said generator for processing said first training signal to derive a processed training signal;

an adaptive equalizer coupled to said receive portion for equalizing said processed training signal to derive an equalized training signal;

a processor coupled to said adaptive equalizer and coupled to said second training signal for comparing said equalized training signal and said second training signal using an adaptive algorithm for deriving coefficients for said adaptive equalizer to compensate for the variations in said receive portion, and for adjusting said adaptive equalizer in accordance with said coefficients to derive a compensated output signal.

11. The apparatus of claim 10, wherein said generator is arranged to generate a pseudo-random PN sequence.

12. The apparatus of claim 10, wherein said receive portion comprises an analog section coupled to said generator for inserting said first training signal into said analog section.

13. The apparatus of claim 12, wherein said analog section comprises a DC offset correction loop having a feedback path coupled to said generator for inserting said first training signal into said feedback path.

14. The apparatus of claim 10, wherein said generator comprises a desired target receive filter coupled to said first training signal for processing said first training signal to derive said second training signal.

15. The apparatus of claim 14, wherein said processor is programmed to adjust a response of a path through both said receive portion and said adaptive equalizer to match the response through said desired target receive filter.

16. The apparatus of claim 10, wherein said generator is arranged to generate said first and second training signals such that said first and second training signals are identical to one another.

17. The apparatus of claim 16, wherein said processor is programmed to adjust said adaptive equalizer to maintain a response substantially equal to an inverse of the response of said receive portion.

18. A wireless communication device, comprising:

at least one of a receiver and a transceiver, comprising a receive portion that can have variations in response;

a generator coupled to said receive portion for generating first and second training signals that originate within the device instead of being received from a source outside the device, wherein said receive portion is arranged to process said first training signal to derive a processed training signal;

an adaptive equalizer coupled to said receive portion for equalizing said processed training signal to derive an equalized training signal;

a processor coupled to said adaptive equalizer and coupled to said second training signal for comparing said equalized training signal and said second training signal using an adaptive algorithm for deriving coefficients for said adaptive equalizer to compensate for the variations in said receive portion, and for adjusting said adaptive equalizer in accordance with said coefficients to derive a compensated output signal.

19. The wireless communication device of claim 18, wherein said generator is arranged to generate a pseudo-random PN sequence.

20. The wireless communication device of claim 18, wherein said receive portion comprises an analog section coupled to said generator for inserting said first training signal into said analog section.

21. The wireless communication device of claim 20, wherein said analog section comprises a DC offset correction loop having a feedback path coupled to said generator for inserting said first training signal into said feedback path.