Bluetooth access code assisted initial DC estimation and frame synchronization

• US 7,221,717 B2
• Filed: 04/25/2006
• Issued: 05/22/2007
• Est. Priority Date: 10/22/2001
• Status: Expired due to Fees

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Yuan, Rebecca W., Indirabhai, Jyothis, Yen, Kevin
• Primary Examiner(s): Kim, Kevin
• Application Number:
  US11/411,469
• Publication Number:
  US 20060262836A1
• Time in Patent Office: 392 Days
• Field of Search: 375/285, 375/316, 375/317, 375/318, 375/319, 375/345, 375/346, 327/306, 327/307, 455/63.1, 455/296, 455/501
• US Class Current: 375/319
• CPC Class Codes: H04J 3/0608 Detectors therefor, e.g. correlators, state machines
• CPC Class Codes: H04L 25/061 providing hard decisions only; arrangements for tracking or suppressing unwanted low frequency components, e.g. removal of dc offset removal of dc offset in coupling arrangements H04L25/029, H04L25/0296
• CPC Class Codes: H04L 25/062 Setting decision thresholds using feedforward techniques only
• CPC Class Codes: H04L 7/042 Detectors therefor, e.g. correlators, state machines digital correlators in general G06F17/15

Abstract

A system for calculating DC offset and achieving frame detection is described. In one embodiment, the present invention includes an electronic device with an integrated receiver module. The receiver module can take advantage of a known synchronization pattern such as the Bluetooth access code to determine an initial DC offset and to provide frame detection.

Claims

1. A method for operating a wireless Bluetooth-enabled communication device, comprising:

computing a compensated DC average for a first plurality of bits of an incoming pilot signal using a DC compensation factor and a DC average;

adjusting an indication of a received first plurality of bits according to the computed compensated DC average;

comparing the adjusted indication of the received first plurality of bits with corresponding bits of a known pilot signal; and

responsive to a threshold number of bits of the adjusted indication of the received first plurality of bits matching the corresponding bits of the known pilot signal, outputting the compensated DC average for the first plurality of bits.

2. The method according to claim 1, comprising:

locating a symbol peak in a received second plurality of bits of the incoming pilot signal; and

using the symbol peak to determine a symbol timing of the incoming pilot signal.

3. The method according to claim 2, comprising:

adjusting an indication of a received third plurality of bits according to the computed compensated DC average;

comparing the adjusted indication of the received third plurality of bits with corresponding bits of the known pilot signal; and

responsive to the threshold number of bits of the adjusted indication of the received first plurality of bits matching the corresponding bits of the known pilot signal and responsive to a threshold number of bits of the adjusted indication of the received third plurality of bits matching the corresponding bits of the known pilot signal, providing the compensated DC average for the first plurality of bits to a DC tracker.

4. The method according to claim 1, comprising:

outputting the compensated DC average for the first plurality of bits to a DC tracker.

5. The method according to claim 1, wherein the known pilot signal comprises a frame sync pattern.

6. A wireless communication device, comprising:

a receiver that is configured to compute a compensated DC average for a first plurality of bits of an incoming pilot signal using a DC compensation factor and a DC average, configured to adjust an indication of a received first plurality of bits according to the computed compensated DC average, configured to compare the adjusted indication of the received first plurality of bits with corresponding bits of a known pilot signal, and configured to provide the compensated DC average for the first plurality of bits in response to a threshold number of bits of the adjusted indication of the received first plurality of bits matching the corresponding bits of the known pilot signal.

7. The wireless communication device according to claim 6,

wherein the receiver is configured to locate a symbol peak in a received second plurality of bits of the incoming pilot signal;

and

wherein the receiver is configured to use the symbol peak to determine a symbol timing of the incoming pilot signal.

8. The wireless communication device according to claim 6, wherein the receiver comprises a Bluetooth-enabled receiver.

9. A method for operating a wireless Bluetooth-enabled communication device, comprising:

computing a compensated DC average using a DC average and a DC compensation factor;

determining whether a threshold number of bits of a first portion of a received synchronization word as adjusted by the DC compensation factor match corresponding bits in a known synchronization word; and

responsive to a threshold number of bits of the first portion of the received synchronization word as adjusted by the DC compensation factor matching the corresponding bits in the known synchronization word, providing the compensated DC average to an offset tracking device.

10. The method according to claim 9, comprising:

determining whether a threshold number of bits of a second portion of the received synchronization word as adjusted by the DC compensation factor match corresponding bits in the known synchronization word; and

responsive to a threshold number of bits of the second portion of the received synchronization word as adjusted by the DC compensation factor matching the corresponding bits in the known synchronization word, providing a second compensated DC average to the offset tracking device.

11. A wireless communication device, comprising:

a receiver configured to compute a compensated DC average using a DC average and a DC compensation factor, configured to determine whether a threshold number of bits of a first portion of a received synchronization word as adjusted by the DC compensation factor match corresponding bits in a known synchronization word, and configured to provide the compensated DC average to an offset tracker of the receiver in response to a threshold number of bits of the first portion of the received synchronization word as adjusted by the DC compensation factor matching the corresponding bits in the known synchronization word.

12. The wireless communication device according to claim 11,

wherein the receiver is configured to determine whether a threshold number of bits of a second portion of the received synchronization word as adjusted by the DC compensation factor match corresponding bits in the known synchronization word, and

wherein the receiver is configured to provide a second compensated DC average to the offset tracker in response to a threshold number of bits of the second portion of the received synchronization word as adjusted by the DC compensation factor matching the corresponding bits in the known synchronization word.

13. The wireless communication device according to claim 11, wherein the receiver comprises a Bluetooth-enabled receiver.

14. A method for operating a wireless communication device, comprising:

computing a compensated DC average using a DC average and a DC compensation factor;

determining whether a threshold number of bits of a first portion of a received synchronization word as adjusted by the DC compensation factor match corresponding bits in a known synchronization word;

responsive to a threshold number of bits of the first portion of the received synchronization word as adjusted by the DC compensation factor matching the corresponding bits in the known synchronization word, providing the compensated DC average to an offset tracking device; and

determining whether a threshold number of bits of a second portion of the received synchronization word as adjusted by the DC compensation factor match corresponding bits in the known synchronization word; and

responsive to a threshold number of bits of the second portion of the received synchronization word as adjusted by the DC compensation factor matching the corresponding bits in the known synchronization word, providing a second compensated DC average to the offset tracking device.