Intensity modulation coherent detection system and method based on ASK (Amplitude Shift Keying) and DBPSK (Differential Binary Phase Shift Keying)

Abstract

The invention discloses an intensity modulation coherent detection system and method based on ASK and DBPSK relating to the coherent detection field. The system comprises a sending end and a receiving end. The first DFB (Distributed Feedback Laser) laser of the sending end sends optical carriers; united modulation is carried out to electric signals by a united modulation unit basing on ASK and DBPSK; an MZM (Mach-Zehnder Modulator) modulator loads the electric signals after united modulation to the optical carriers to obtain polarization signals; the polarization signals are sent to the receiving end; the second DFB laser of the receiving end sends local oscillation light; a coherent receiver carries out coherent receiving to the polarization signals sent by the MZM modulator basing on the local oscillation light; the real parts and imaginary parts of the polarization signals are respectively generated; the polarization signals are converted into digital signals through an ADC (Analog-Digital Converter); digital signal processing is carried out by a DSP (Digital Signal Processor). According to the invention, the cost of the system is reduced; the receiving sensitivity of the system is effectively improved; the spectrum efficiency is remarkably improved; and the power consumption of the system is reduced.

Description

technical field [0001] The present invention relates to the field of coherent detection, in particular to an intensity modulation coherent detection system and method based on ASK (Amplitude Shift Keying, amplitude shift keying) and DBPSK (Differential Binary Phase Shift Keying, differential binary phase shift keying). Background technique [0002] As the transmission rate requirements of the metropolitan area network and the access network increase day by day, coherent detection technology has been widely used. However, the difference between metropolitan area network and access network and long-distance coherent optical transmission is that its transmission distance is relatively short. The cost of the existing coherent detection system is relatively high, and users hope to reduce the cost. Therefore, the low-cost intensity modulation coherent detection system is more suitable for short-distance metropolitan area network and access network. [0003] There are two existin...

AI Technical Summary

Problems solved by technology

However, the intensity-modulated coherent detection system based on the polarization multiplexing of the traditional modulation format has a low spectrum utilization rate, and the power consumption of the system is also large

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