Non-linear equalization for the upstream data connection of 56K PCM modems
First Claim
1. A server-side equalization system, comprising:
- a primary communication channel for transmission of a primary signal;
a secondary communication channel for transmission of a secondary signal;
a client communication device sending the primary signal and having a pre-equalization module communicatively coupled to the primary communication channel, the pre-equalization module for modifying the primary signal being sent by the client communication device;
a server communication device having a linear equalizer communicatively coupled to the primary communication channel for receiving data from the primary communication channel;
a sampling module communicatively coupled to the primary communication channel for sampling the primary signal; and
a non-linear decision feedback equalizer communicatively coupled to the secondary communication channel for providing pre-equalization coefficients to the pre-equalization module of the client communication device based on analysis of samples taken from the sampling module, the pre-equalization coefficients being used by the pre-equalization module for correcting non-linear distortions in the primary signal being sent upstream to the server communication device, and wherein the client communication device performs a portion of the analysis of the samples taken by the sampling device for developing the pre-equalization coefficients.
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Accused Products
Abstract
An apparatus and method for minimizing nonlinear distortions in computer system communications where the upstream signal from a client modem to a server modem is periodically sampled, the samples being utilized by a non-linear decision feedback equalizer to periodically produce sets of equalizer coefficients. The equalizer coefficients are sent via an independent communication channel downstream to the client modem to continuously update distortion-minimizing adjustments to the client modem'"'"'s upstream output. The samples are taken periodically in order to update the non-linear decision feedback equalizer so that it can provide appropriate equalizer coefficients for the changing characteristics of the upstream signal. The method includes identifying, by a first communication system, nonlinear equalization parameters to be used by a second communication system to minimize nonlinear distortions on a primary communication channel. The method also includes transmitting, by the first communication system, the nonlinear equalization parameters to the second communication system by a secondary communication channel. In addition, the method includes receiving, by the second communication system, the nonlinear equalization parameters from the first communication system. Finally, the method includes utilizing, by the second communication system, the nonlinear equalization parameters to minimize nonlinear distortion on the primary communication channel.
77 Citations
22 Claims
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1. A server-side equalization system, comprising:
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a primary communication channel for transmission of a primary signal;
a secondary communication channel for transmission of a secondary signal;
a client communication device sending the primary signal and having a pre-equalization module communicatively coupled to the primary communication channel, the pre-equalization module for modifying the primary signal being sent by the client communication device;
a server communication device having a linear equalizer communicatively coupled to the primary communication channel for receiving data from the primary communication channel;
a sampling module communicatively coupled to the primary communication channel for sampling the primary signal; and
a non-linear decision feedback equalizer communicatively coupled to the secondary communication channel for providing pre-equalization coefficients to the pre-equalization module of the client communication device based on analysis of samples taken from the sampling module, the pre-equalization coefficients being used by the pre-equalization module for correcting non-linear distortions in the primary signal being sent upstream to the server communication device, and wherein the client communication device performs a portion of the analysis of the samples taken by the sampling device for developing the pre-equalization coefficients. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A server-side equalization system, comprising:
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a primary communication channel for transmission of a primary signal;
a secondary communication channel for transmission of a secondary signal;
a client communication device sending the primary signal and having a pre-equalization module communicatively coupled to the primary communication channel, the pre-equalization module for modifying the primary signal being sent by the client communication device;
a server communication device having a linear equalizer communicatively coupled to the primary communication channel for receiving data from the primary communication channel;
a sampling module communicatively coupled to the primary communication channel for sampling the primary signal; and
a non-linear decision feedback equalizer communicatively coupled to the secondary communication channel for providing pre-equalization coefficients to the pre-equalization module of the client communication device based on analysis of samples taken from the sampling module, the pre-equalization coefficients being used by the pre-equalization module for correcting non-linear distortions in the primary signal being sent upstream to the server communication device, and wherein the client communication device and the server communication device each perform a portion of the analysis of the samples for development of pre-equalization coefficients and exchange the pre-equalization coefficients with each other.
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10. A communication system, comprising:
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a primary communication channel for transmission of a primary signal;
a secondary communication channel for transmission of a secondary signal;
a first communication device having a pre-equalization module communicatively coupled to the primary communication channel, the pre-equalization module for modifying the primary signal being sent by the first communication device;
a second communication device having an equalizer communicatively coupled to the primary communication channel for receiving data from the primary communication channel;
a sampling module communicatively coupled to the primary communication channel for sampling the primary signal; and
another equalizer communicatively coupled to the secondary communication channel for providing pre-equalization coefficients to the pre-equalization module of the first communication device based on analysis of samples taken from the sampling module, wherein the first communication device performs a portion of the analysis of the samples taken by the sampling device for developing the pre-equalization coefficients. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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19. A communication system, comprising:
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a primary communication channel for transmission of a primary signal;
a secondary communication channel for transmission of a secondary signal;
a first communication device having a pre-equalization module communicatively coupled to the primary communication channel, the pre-equalization module for modifying the primary signal being sent by the first communication device;
a second communication device having an equalizer communicatively coupled to the primary communication channel for receiving data from the primary communication channel;
a sampling module communicatively coupled to the primary communication channel for sampling the primary signal; and
another equalizer communicatively coupled to the secondary communication channel for providing pre-equalization coefficients to the pre-equalization module of the first communication device based on analysis of samples taken from the sampling module, wherein the first communication device and the second communication device each perform a portion of the analysis of the samples for development of pre-equalization coefficients and exchange the pre-equalization coefficients with each other.
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20. A method for performing non-linear equalization in a system for transmitting data that utilizes pre-equalization, comprising:
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sampling a communication channel;
analyzing a portion of the samples at a server device to calculate pre-equalization coefficients;
further comprising;
determining the processing capability of the client device;
determining an allocation of pre equalization analysis processing between the client device and the server device; and
analyzing a portion of the samples at a client device to calculate pre equalization coefficients. - View Dependent Claims (21, 22)
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Specification