US 7,561,633 B2 · System and method for MIMO equalization for DSP transceivers

Abstract

A method to efficiently deal with FEXT crosstalk in wireline communication system via MIMO equalization is presented. A MIMO-DFE based receiver architecture is developed to demonstrate the advantage over the traditional receiver design. A MIMO structure for systems with TH precoding is also developed for 10GBASE-T application. The proposed architecture overcomes the limitation of the traditional schemes and achieves a better SNR performance and lower receiver complexity. The proposed method relies on the fact that FEXT inherently contains information about the symbols transmitted from the three far end transmitters and it can be viewed as a signal rather than noise. Therefore, MIMO techniques are applied to turn FEXT into a benefit for the receiver design.

Claims24

Dependent claims

A communications transceiver, comprising:

i. N transmitters;
ii. An N-input N-output receiver, comprising:
(a) A multi-input multi-output (MIMO) canceller filter, with N inputs and N outputs, for canceling echo and near end cross talk (NEXT), coupled to the outputs of the N transmitters, comprising a plurality of feed-forward digital filters with self and cross connections;
(b) A MIMO feed-forward equalizer (FFE) containing a plurality of digital filters with self and cross connections;
(c) A MIMO decision-feedback equalizer (DFE), containing a plurality of digital filters with self and cross connections, used for far-end cross talk processing;
(d) N decision devices or slicers, whose inputs are controlled by the outputs of the MIMO canceller filter, MIMO feed-forward equalizer, and MIMO decision-feedback equalizer, whose outputs are coupled to the MIMO decision-feedback equalizer, and are the outputs of the receiver;
(e) Generation of N first error signals by subtracting the inputs of the N slicers from their corresponding outputs, used to adapt the coefficients of the digital filters.

4 more elements

A communications transceiver, comprising:

i. N transmitters, wherein each transmitter contains a precoder filter;
ii. An N-input N-output receiver, comprising:
(a) A multi-input multi-output (MIMO) canceller filter, with N inputs and N outputs, for canceling echo and near end cross talk (NEXT), coupled to the outputs of the N transmitters, comprising a plurality of feed-forward digital filters with self and cross connections;
(b) A MIMO feed-forward equalizer (FFE) containing a plurality of digital filters with self and cross connections, coupled to the N received input signals;
(c) A MIMO decision-feedback equalizer (DFE), containing a plurality of digital filters with cross connections;
(d) N modulo devices controlled by the N outputs of the MIMO DFE, N outputs of the MIMO FFE and the N outputs of the MIMO Echo & NEXT canceller;
(e) N decision devices or slicers, whose inputs are the outputs of the N modulo devices, and whose outputs are the outputs of the receiver;
(f) Generation of N first error signals by subtracting the inputs of the N slicers from their corresponding outputs, used to adapt the coefficients of the digital filters in MIMO DFE, MIMO FFE, and MIMO Echo & NEXT canceller;
(g) Generation of N first desired signals by taking the sum of the N inputs of the modulo devices and their corresponding said first error signals, which are coupled to the cross feedback filters in the MIMO DFE.

6 more elements

An integrated circuit having a substrate and a communications transceiver disposed on said substrate, said communications transceiver comprising:

i. N transmitters;
ii. An N-input N-output receiver, comprising:
(a) A multi-input multi-output (MIMO) canceller filter, with N inputs and N outputs, for canceling echo and near end cross talk (NEXT), coupled to the outputs of the N transmitters, comprising a plurality of feed-forward digital filters with self and cross connections;
(b) A MIMO feed-forward equalizer (FFE) containing a plurality of digital filters with self and cross connections;
(c) A MIMO decision-feedback equalizer (DFE), containing a plurality of digital filters with self and cross connections, used for far-end cross talk processing;
(d) N decision devices or slicers, whose inputs are controlled by the outputs of the MIMO canceller filter, MIMO feed-forward equalizer, and MIMO decision-feedback equalizer, whose outputs are coupled to the MIMO decision-feedback equalizer, and are the outputs of the receiver;
(e) Generation of N first error signals by subtracting the inputs of the N slicers from their corresponding outputs, used to adapt the coefficients of the digital filters.