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US 9,432,123 B2Granted
Adaptive mach zehnder modulator linearization
AssigneeInphi Corporation
InventorHari Shankar
Life of this patent
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Abstract
The present invention is directed to optical communication systems and methods thereof. In various embodiments, the present invention provides method for linearizing Mach Zehnder modulators by digital pre-compensation and adjusting the gain of the driver and/or the modulation index. The pre-compensation can be implemented as a digital pre-compensation algorithm, which is a part of an adaptive feedback loop. There are other embodiments as well.
Claims19
A modulation system comprising:
- a nonlinear mapping module being configured to perform a mapping process to generate a voltage signal using a modulation signal and a first modulation index using an inverse transformation function;
- a DAC module being configured to convert the voltage signal to an analog signal;
- a driver module being configured to generate a driving signal using the analog signal and a gain value, the driver module further being configured to adjust the gain value in response to a compensation signal;
- a peak detection module in a transmitter being configured to determine a peak value associated with the driving signal;
- an MZ modulator being configured to generate an output signal using at least the driving signal, the output signal being associated a half wave voltage value;
- and
- a compensation module being configured to generate the compensation signal using at least the first modulation index and the second module index, the second modulation index being a function of the peak value and the half wave voltage value.
4 more elements
A modulation system comprising:
- a nonlinear mapping module being configured to perform a mapping process to generate a voltage signal using a modulation signal and an adjustable modulation index value using an inverse transformation function;
- a DAC module being configured to convert the voltage signal to an analog signal;
- a driver module being configured to generate a driving signal using the analog signal and a gain value;
- a peak detection module in a transmitter being configured to determine a peak value associated with the driving signal;
- an MZ modulator being configured to generate an output signal using at least the driving signal, the output signal being associated a half wave voltage value;
- and
- a compensation module being configured to determine the adjustable modulation index value based on the peak value and the half wave voltage value.
4 more elements
A method for modulating signals comprising:
- performing nonlinear mapping a modulation signal using a first modulation index to generate a voltage signal using an inverse transformation function;
- processing the voltage signal using a linear equation;
- converting the processed voltage signal to an analog signal;
- processing the analog signal at a gain value to generate a driving signal;
- measuring a peak voltage of the driving signal in a transmitter;
- performing MZ modulation on the driving signal to generate an output signal;
- determining a second modulation index based at least on the driving signal and the first modulation index;
- and
- adjusting the gain value using the second modulation index.
6 more elements
Dependencies are inferred from the claim text.