Non-linear equalization for the upstream data connection of 56K PCM modems

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 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.

A communication system, comprising:

• 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.

A communication system, comprising:

• 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.

A method for performing non-linear equalization in a system for transmitting data that utilizes pre-equalization, comprising:

• 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.