Symbol Error Injection for Timing Recovery

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Solution Overview

Problem

In high-speed data communications, receivers face timing recovery failures due to high frequency content in data streams, especially when the data transition rate exceeds the nominal operating bandwidth of the receiver, leading to synchronization issues and service disruptions.

Innovation Solution

The transmitter injects symbol errors into the data stream before transmission, using forward error correcting (FEC) coding, to reduce the data transition rate and ensure timing recovery robustness, even for receivers with limited operating bandwidth.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the transmitter transmits data at high speed (10 Gbps), then the communication rate is improved, but the data transition rate exceeds the receiver's nominal operating bandwidth (2.5 Gbps), causing timing recovery failures

Engineering Contradiction:

Improvecommunication rateVSAvoidtiming recovery robustness

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent intentionally injects symbol errors into the data stream, converting what would normally be harmful errors into a beneficial mechanism. These injected errors reduce the data transition rate to match the receiver's bandwidth limitations, thereby preventing timing recovery failures while maintaining high-speed communication capability

Inventive Principle:

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

Solution Approach 2:

The patent changes the parameter of data transition rate by injecting symbol errors. This modifies the frequency content of the data stream to be compatible with the receiver's nominal operating bandwidth, allowing the receiver to perform timing recovery successfully even when the nominal communication rate exceeds the receiver's bandwidth

Inventive Principle:

Principle #35Parameter changes

2Reliability

If symbol errors are injected to reduce data transition rate, then timing recovery robustness is improved, but data integrity is worsened

Engineering Contradiction:

Improvetiming recovery robustnessVSAvoiddata integrity

Core Design Contradiction:

ReliabilityVSLoss of information

Solution Approach 1:

The patent applies forward error correcting (FEC) coding before transmitting the data stream. This creates a cushion of error correction capability that can compensate for the intentionally injected symbol errors, ensuring that data integrity is maintained despite the errors used to reduce transition rate

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The patent converts harmful symbol errors into a beneficial tool by using them to control data transition rate. The FEC coding ensures that these otherwise harmful errors do not result in actual data loss, as they can be corrected at the receiver end

Inventive Principle:

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

Data Source

PatentUS10063353B2Injected block code distortion

Publication Date: 2018.08.28 ADTRAN INC

AI summary

Methods, systems, and apparatus for automatically injecting symbol errors into a data stream prior to transmitting the data stream for timing recovery robustness are disclosed. In one aspect, a first telecommunications device determines that a data transition rate of a data stream exceeds a pre-specified rate. In response to the determination that the data transition rate exceeds the pre-specified rate, the first telecommunications device injects symbol errors into the data stream prior to transmitting the data stream to a second telecommunications device. The pre-specified rate is based on at least a nominal passband of the second telecommunications device.