Optical Transmitter PAPR Control via Distributed Compensation
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Solution Overview
Problem
Optical transmitters exhibit low-pass transmission characteristics, leading to increased high-frequency waves and a large peak-to-average-power ratio (PAPR), which results in non-linear effects and degradation of transmission characteristics.
Innovation Solution
A method and system that compensates transmission characteristics by using a transmitter compensation unit to set PAPR to a predetermined value, preventing non-linear effects by adjusting transmitter compensation characteristics and ensuring receiver compensation characteristics make overall transmitter-receiver characteristics flat.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If compensation characteristics that enhance high-frequency region are set to transmitter compensation unit to flatten transmission characteristics, then transmission characteristics become flat, but peak-to-average-power ratio becomes large and non-linear effect occurs in optical transmitter
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the compensation characteristics of the transmitter compensation unit based on the calculated PAPR value. When PAPR exceeds the threshold, the compensation characteristics are modified to reduce high-frequency enhancement, thereby lowering PAPR and avoiding non-linear effects while maintaining acceptable transmission characteristics flatness through receiver-side compensation.
2Manufacturing precision
If high-frequency waves are enhanced to compensate low-pass characteristics, then transmission characteristics improve, but waveform rise becomes steep and PAPR increases
Solution Approach 1:
The patent implements feedback by calculating the PAPR of the output signal from the transmitter compensation unit and using this information to adjust the compensation characteristics. The PAPR calculation unit continuously monitors the signal and provides feedback to control the compensation characteristics, creating a closed-loop system that adapts to prevent excessive PAPR while maintaining transmission quality.
3Object-affected harmful factors
If all compensation is performed at receiver side, then transmitter non-linear effect is avoided, but transmission rate and multiple-value modulation performance degrade
Solution Approach 1:
The patent applies partial action by having the transmitter compensation unit perform only part of the compensation function, specifically optimized to avoid excessive PAPR and non-linear effects. The remaining compensation is performed at the receiver side, creating a distributed compensation approach that balances the trade-off between avoiding non-linear effects and maintaining high transmission rates with multiple-value modulation.
Data Source
AI summary
Part of compensation of the transmission characteristics of the optical transmitter is performed by transmitter compensation circuitry disposed at a stage prior to the optical transmitter. Remaining part of compensation of the transmission characteristics of the optical transmitter and compensation of the transmission characteristics of the optical receiver is performed by a receiver compensation circuitry disposed at a stage subsequent to the optical receiver. Transmitter compensation characteristics of the transmitter compensation circuitry is set so that a peak-to-average-power ratio of an output signal from the transmitter compensation circuitry becomes equal to or smaller than a predetermined value.