Transceiver Staged Training for Interference Cancellation

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Solution Overview

Problem

In communication systems like IEEE 802.3ab and IEEE 802.3an Ethernet, transceivers face challenges in converging parameters during the start-up procedure due to interference from echoes, near-end cross talks, and far-end cross talks, leading to incorrect data reception.

Innovation Solution

A transceiver with a timing recovery circuit, an interference cancellation circuit, and an equalizer, along with an auto-negotiation circuit, performs staged training procedures to determine whether it operates as a master or slave transceiver, training functional blocks to eliminate interference and adjust parameters effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If parameters of functional blocks are trained in decision-directed manner, then the receiver can correctly receive data, but the parameters of functional blocks cannot converge to proper values due to mutual influence between blocks

Engineering Contradiction:

Improvedata reception correctnessVSAvoidparameter convergence

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent segments the training process into two distinct stages: a data-directed training stage followed by a decision-directed training stage. This segmentation allows the system to first establish proper parameter convergence using known signals, then transition to data-directed operation, thereby resolving the contradiction between reliability and stability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies preliminary action by performing data-directed training with known signals before transitioning to decision-directed training. This preliminary configuration of parameters using controlled signals ensures proper convergence before the system operates in normal data reception mode, preventing the mutual influence problem from occurring.

Inventive Principle:

Principle #10Preliminary action

2Productivity

If four pairs of transceivers perform communication simultaneously, then communication capacity is increased, but interference from echoes and cross-talks degrades signal reception quality

Engineering Contradiction:

Improvecommunication capacityVSAvoidsignal interference

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful interference from echoes and cross-talks into a beneficial training opportunity. By using these interference signals during the data-directed training stage, the system learns to cancel them out, transforming what would be detrimental factors into useful information for improving reception quality.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent introduces training sequences as an intermediary element that mediates between the transmitted signals and the reception process. These known signals serve as a reference that allows the receiver to distinguish between desired signals and interference, enabling proper parameter training despite the presence of multiple simultaneous transmissions.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Productivity

If transmission rate is increased to near channel capability limit, then data transmission efficiency is improved, but far-end cross-talks become significant and require effective cancellation mechanisms

Engineering Contradiction:

Improvetransmission rateVSAvoidfar-end cross-talks

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent applies preliminary action by configuring the interference cancellation parameters during the data-directed training stage before high-rate data transmission begins. This advance preparation ensures that the cancellation mechanisms are properly tuned to handle the significant far-end cross-talks that will be present during high-speed operation.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback mechanisms where the receiver uses the known training signals to estimate interference characteristics and feed this information back to adjust cancellation parameters. This closed-loop approach enables the system to adapt to the increased cross-talk levels resulting from higher transmission rates.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS8891601B2Apparatus and method for start-up in communication system

Publication Date: 2014.11.18 REALTEK SEMICON CORP

AI summary

A transceiver in a communication system and a start-up method thereof are provided. The transceiver comprises an auto-negotiation circuit, a timing recovery circuit, an interference cancellation circuit and an equalizer. The auto-negotiation circuit performs an auto-negotiation procedure to determine whether the transceiver operates as a master or slave transceiver. If the transceiver operates as a slave transceiver, it executes a first stage and a second stage during the start-up process. In the first stage, the transceiver performs channel estimation to generate a channel estimation value, presets the parameters of the equalizer according to the channel estimation value, and trains the timing recovery circuit and the equalizer; in the second stage, the transceiver trains the interference cancellation circuit.