High-speed method and device thereof for modulating multi-system light with minimum-frequency by shift keying

Abstract

The invention relates to a high-speed method and a device thereof for modulating multi-system light with minimum-frequency by shift keying. The method adopts the cascading mode of 2FSK (Frequency Shift Keying) and 2MSK (Minimum Shift Keying) to generate 4-system MSK signals, the first-stage modulation generates FSK signals the frequency difference of which is shown in the specification; the second-stage modulation splits the 2FSK signals to generate 4MSK signals with the frequency difference being 1 / 2TS and keep the continuous phase position. The method and the device realizing 4-system light MSK can generate 4-system light MSK signals with constant envelope, continuous phase position and strict orthogonality.

Description

technical field [0001] The present invention relates to a high-speed multi-ary system optical minimum frequency shift keying modulation method and device, in particular to a high-speed multi-ary system optical minimum frequency shift keying modulation method and device based on cascade mode. Background technique [0002] The research on signal modulation format is a hot spot in the field of optical communication. The improvement of the transmission performance of the new modulation format has attracted people's attention, especially in suppressing nonlinear effects, improving dispersion tolerance and PMD tolerance. good effect. In the optical fiber communication system, the continuous light wave or light pulse train emitted by the light source does not carry information and can only be used as a carrier of information. The optical carrier signal is a signal related to the polarization direction, signal amplitude, carrier frequency, and carrier phase. If any one of the four ...

AI Technical Summary

Problems solved by technology

However, this internal modulation method is difficult to achieve high-speed modulation. First, due to the limitation of the response speed of the semiconductor laser itself, and second, this modulation method is accompanied by frequency chirp, which broadens the output signal spectrum and limits the transmission capacity of the system.

Images