METHODS AND APPARATUS FOR SYNCHRONIZATION IN MULTIPLE-CHANNEL COMMUNICATION SYSTEMS

• US 20120087449A1
• Filed: 12/27/2010
• Published: 04/12/2012
• Est. Priority Date: 12/27/2009
• Status: Active Grant

• Current Assignee: Entropic Communications, LLC (SoftBank Group Corp.)
• Original Assignee: Maxlinear Incorporated
• Inventors: LING, CURTIS, GALLAGHER, TIMOTHY
• Granted Patent: US 8,681,900 B2
• Time in Patent Office: Days
• US Class Current: 375/346
• CPC Class Codes: H04L 1/20 using signal quality detector
• CPC Class Codes: H04L 2027/003 at baseband only
• CPC Class Codes: H04L 2027/0038 using an equaliser
• CPC Class Codes: H04L 2027/0067 Phase error detectors
• CPC Class Codes: H04L 2027/0075 Error weighting
• CPC Class Codes: H04L 25/0204 of multiple channels
• CPC Class Codes: H04L 27/2627 Modulators
• CPC Class Codes: H04L 27/2649 Demodulators
• CPC Class Codes: H04L 27/2659 Coarse or integer frequency offset determination and synchronisation
• CPC Class Codes: H04L 27/266 Fine or fractional frequency offset determination and synchronisation
• CPC Class Codes: H04L 27/2695 with channel estimation, e.g. determination of delay spread, derivative or peak tracking channel estimation H04L25/0202

Abstract

Methods and apparatus for processing multichannel signals in a multichannel receiver are described. In one implementation, a plurality of demodulator circuits may provide a plurality of outputs to a processing module, with the processing module then simultaneously estimating noise characteristics based on the plurality of outputs and generating a common noise estimate based on the plurality of outputs. This common noise estimate may then be provided back the demodulators and used to adjust the demodulation of signals in the plurality of demodulators to improve phase noise performance.

Claims

1. A method for improving multichannel receiver performance, comprising:

determining, for a first of a plurality of signals corresponding to a first of a plurality of channels received at the multichannel receiver, a first weighting metric;

weighting, based at least in part on the first weighting metric, a raw phase error signal associated with the first of a plurality of signals so as to generate a first weighted phase error signal;

determining, for a second of a plurality of signals corresponding to a second of a plurality of channels received at the multichannel receiver, a second weighting metric;

weighting, based at least in part on the second weighting metric, a raw phase error signal associated with the second of a plurality of signals so as to generate a second weighted phase error signal;

combining the first weighted phase error signal and the second weighted phase error signal so as to generate a common phase error feedback signal; and

providing the common phase error feedback signal to ones of a plurality of demodulator modules so as to correct a phase error in the demodulator modules.

2. A multichannel receiver apparatus, comprising:

a receiver module configured to receive a first plurality of signals corresponding to a first of a plurality of channels and a second of a plurality of signals corresponding to a second of a plurality of channels received as the multichannel receiver; and

a signal processor module configured to;

determine, for the first of the plurality of signals, a first weighting metric;

weigh, based at least in part on the first weighting metric, a raw phase error signal determined for the first of a plurality of signals so as to generate a first weighted phase error signal;

determine, for the second of the plurality of signals, a second weighting metric;

weigh, based at least in part on the second weighting metric, a raw phase error signal associated with the second of a plurality of signals so as to generate a second weighted phase error signal;

combine the first weighted phase error signal and the second weighted phase error signal so as to generate a common phase error feedback signal; and

provide the common phase error feedback signal to ones of a plurality of demodulator modules so as to correct a phase error in the demodulator modules.

3. A multichannel receiver apparatus, comprising:

means for determining, for a first of a plurality of signals corresponding to a first of a plurality of channels received at the multichannel receiver, a first weighting metric;

means for weighting, based at least in part on the first weighting metric, a raw phase error signal associated with the first of a plurality of signals so as to generate a first weighted phase error signal;

means for determining, for a second of a plurality of signals corresponding to a second of a plurality of channels received at the multichannel receiver, a second weighting metric;

means for weighting, based at least in part on the second weighting metric, a raw phase error signal associated with the second of a plurality of signals so as to generate a second weighted phase error signal;

means for combining the first weighted phase error signal and the second weighted phase error signal so as to generate a common phase error feedback signal; and

means for providing the common phase error feedback signal to ones of a plurality of demodulator modules so as to correct a phase error in the demodulator modules.

4. A computer program product comprising a computer-readable medium including codes for causing a computer to:

determine, for a first of a plurality of signals corresponding to a first of a plurality of channels received at the multichannel receiver, a first weighting metric;

weigh, based at least in part on the first weighting metric, a raw phase error signal associated with the first of a plurality of signals so as to generate a first weighted phase error signal;

determine, for a second of a plurality of signals corresponding to a second of a plurality of channels received at the multichannel receiver, a second weighting metric;

weigh, based at least in part on the second weighting metric, a raw phase error signal associated with the second of a plurality of signals so as to generate a second weighted phase error signal;

combine the first weighted phase error signal and the second weighted phase error signal so as to generate a common phase error feedback signal; and

provide the common phase error feedback signal to ones of a plurality of demodulator modules so as to correct a phase error in the demodulator modules.

5. A method for improving multichannel receiver performance, comprising:

estimating, based on ones of a plurality of outputs of a plurality of demodulator circuits in response to receipt of corresponding ones of a plurality of received signals, a phase noise; and

adjusting, responsive to said estimating, one or more of the plurality of received signals so as to enhance demodulation of the one or more of the plurality of received signals.

6. The method of claim 5, further comprising estimating the channel corresponding to two or more of the plurality of received signals;

and

adjusting, responsive to said estimating the channel, the channel estimate of ones of the plurality of channel estimates.

7. A multichannel receiver apparatus, comprising:

a plurality of demodulator circuits; and

a signal processing module configured to;

estimate, based on ones of a plurality of outputs of the plurality of demodulator circuits in response to receipt of corresponding ones of a plurality of received signals, a phase noise; and

adjust, responsive to said estimating, one or more of the plurality of received signals so as to enhance demodulation of the one or more of the plurality of received signals.

8. The apparatus of claim 7, wherein the signal processing module is further configured to:

estimate the channel corresponding to two or more of the plurality of received signals; and

adjust, responsive to said estimating the channel, the channel estimate of ones of the plurality of channel estimates.

9. A multichannel receiver apparatus, comprising:

means for estimating, based on ones of a plurality of outputs of a plurality of demodulator circuits in response to receipt of corresponding ones of a plurality of received signals, a phase noise; and

means for adjusting, responsive to said estimating, one or more of the plurality of received signals so as to enhance demodulation of the one or more of the plurality of received signals.

10. The apparatus of claim 9, further comprising:

means for estimating the channel corresponding to two or more of the plurality of received signals; and

means for adjusting, responsive to said estimating the channel, the channel estimate of ones of the plurality of channel estimates.

11. A computer program product comprising a computer-readable medium including codes for causing a computer to:

estimate, based on ones of a plurality of outputs of a plurality of demodulator circuits in response to receipt of corresponding ones of a plurality of received signals, a phase noise; and

adjust, responsive to said estimating, one or more of the plurality of received signals so as to enhance demodulation of the one or more of the plurality of received signals.

12. The computer program product of claim 11, wherein the instructions further include instructions for causing the computer to:

estimate the channel corresponding to two or more of the plurality of received signals; and

adjust, responsive to said estimating the channel, the channel estimate of ones of the plurality of channel estimates.

13. A method for enhancing multichannel receiver demodulation performance comprising:

receiving a channel bonded multichannel signal;

providing ones of the multichannel signals to a corresponding ones of demodulator circuits;

processing, in the demodulator circuits, the ones of multichannel signals so as to generate a corresponding plurality of output signals;

processing, in parallel, the plurality of output signals to generate a plurality of estimates of a common noise component of the multichannel signals; and

generating, based on the plurality of estimates, a composite estimate of the common noise component.

14. A multichannel receiver apparatus, comprising:

a receiver module configured to receive a channel bonded multichannel signal; and

provide ones of the multichannel signals to a corresponding ones of demodulator circuits;

a demodulator module configured to process ones of the multichannel signals so as to generate a corresponding plurality of output signals; and

a signal processor module configured to;

process, in parallel with the demodulator module, the plurality of output signals to generate a plurality of estimates of a common noise component of the multichannel signals; and

generate, based on the plurality of estimates, a composite estimate of the common noise component.

15. A multichannel receiver apparatus, comprising:

means for receiving a channel bonded multichannel signal;

means for demodulating the ones of multichannel signals so as to generate a corresponding plurality of output signals;

means for processing, in parallel with the demodulator means, the plurality of output signals to generate a plurality of estimates of a common noise component of the multichannel signals; and

means for generating, based on the plurality of estimates, a composite estimate of the common noise component.

16. A method for enhancing multichannel receiver performance, comprising:

generating a plurality of signals corresponding to a plurality of channels received at the multichannel receiver;

generating, based on the plurality of signals, an estimate of a common noise component of the plurality of signals; and

providing the estimate of a common noise component to a plurality of demodulator circuits so as to adjust the demodulators to correct noise.

17. A multichannel communications receiver, comprising:

A plurality of demodulator circuits configured to demodulate multiple cable channels;

a circuit configured to simultaneously generate a plurality of signals corresponding to a plurality of channels of the multichannel signal; and

a processor module configured to generate, based on the plurality of signals, an estimate of a common noise component of the plurality of signals;

wherein the estimate of the common noise component is provided to the plurality demodulators so as to adjust the demodulators to correct noise.

18. A multichannel communications receiver, comprising:

means for simultaneously generating a plurality of signals corresponding to a plurality of signals of a plurality of channels of the multichannel signal;

means for generating, based on the plurality of signals, an estimate of a common noise component of the plurality of signals; and

means for providing the estimate of the common noise component to a plurality demodulators so as to adjust the demodulators to correct noise.