Nonlinear Compensating Apparatus for Optical Transmitters
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Solution Overview
Problem
In optical communication systems, existing methods for compensating intra-channel nonlinearity are complex and require high hardware complexity, especially in phase modulation systems, due to the need for numerous complex additions and interactions, which increases costs and hardware requirements.
Innovation Solution
A nonlinear compensating apparatus and method that combines pulse interactive items based on weighting coefficients to reduce calculation complexity, transforming complex additions into combinations of additions and multiplications of symbols in a finite symbol set, thereby lowering hardware requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the number of pulse interactive items is increased to improve compensation effect for large residual dispersion, then the hardware complexity and calculation complexity increase
Solution Approach 1:
The patent combines multiple pulse interactive items that have the same weighting coefficient into a single consolidated calculation. Instead of separately calculating each pulse interaction and then summing them, the invention merges them by calculating the sum of symbols first and then multiplying by the shared weighting coefficient, significantly reducing the number of multiplication operations required
Solution Approach 2:
The patent segments the calculation process into two distinct stages: first summing the symbols that share the same weighting coefficient, then performing a single multiplication operation. This segmentation transforms the original approach of multiple separate multiplications into a more efficient two-step process
2Ease of operation
If complex additions are used to calculate perturbation quantity, then the calculation is straightforward but the hardware complexity increases
Solution Approach 1:
The patent replaces complex arithmetic operations (complex additions and multiplications) with simpler operations suitable for digital signal processing. By exploiting the properties of symbols in finite symbol sets, the invention transforms the calculation into operations that can be efficiently implemented using lookup tables and simplified logic, reducing hardware complexity while maintaining calculation accuracy
Data Source
AI summary
The present invention provides a nonlinear compensating apparatus and method and a transmitter. The nonlinear compensating apparatus includes: an information sequence acquiring unit, configured to acquire a symbol information sequence of the pulse signal; a perturbation quantity acquiring unit, configured to calculate, by pre-obtained weighting coefficients to which each item corresponds, the weighted sum of interaction items of pulses on one or more moments relative to the current moment; a perturbation quantity processing unit, configured to combine the items of the perturbation quantity based on the weighting coefficients; and an information compensating unit, configured to calculate a difference between the symbol information sequence and the processed perturbation quantity to obtain a compensated symbol information sequence. With the embodiments of the present invention, the complexity of calculation may be further lowered, and requirements on hardware may also be lowered.