Synthesis and open loop synchronization method of photon detection array signal

Abstract

The invention relates to a synthesis and open loop synchronization method of a photon detection array signal, and belongs to the field of deep-space laser communications. The method comprises the following steps: firstly, detecting a PPM (Pulse Position Modulation) signal after channel transmission by N photon detectors; secondly, measuring the arrival time of each photon of each branch signal and finishing the combination of each branch signal; thirdly, performing timing error estimation, and performing PPM time slot data recovery on a composite signal according to estimated initial phase deviation and frequency deviation; and finally, demodulating and outputting. The synthesis and open loop synchronization method of the photon detection array signal provided by the invention realizes PPM time slot synchronization by measuring the arrival time of the photons so as to further realize demodulation; an open loop synchronization mode is adopted to replace a closed loop clock synchronization mode of a phase-locked loop and an early-late gate to realize time slot synchronization; and an array signal synthesis method is simple, easy to implement, low in bit error rate and high in accuracy.

Description

technical field [0001] The invention belongs to the field of deep-space laser communication, and relates to a synthesis and open-loop synchronization method of photon detection array signals. Background technique [0002] Laser communication has many advantages such as large capacity, low power consumption, and small antenna size, and has great development prospects in long-distance space communication. In deep-space laser communication, in order to reduce the requirements for transmitting laser power, pulse position modulation (PulsePosition Modulation, PPM) and photon detector array are two key technologies generally recognized. [0003] Compared with the traditional On-Off Keying (OOK) modulation method, PPM modulation has the advantages of high energy efficiency and strong anti-interference ability. It reduces the requirement for signal energy by widening the signal bandwidth. [0004] The photon detector can detect a single incident photon, and an electron excited by t...

AI Technical Summary

Problems solved by technology

Its main disadvantage is that only one photon can be resolved at a time, and the next photon can only be detected after a long recovery time, so the repetition rate of the device is low

Generally, PPM time slot synchronization is mainly based on closed-loop tracking phase-locked loop and early-late gate method. Due to the need for closed-loop clock synchronization in this closed-loop clock synchronization method, the system is inevitably more complicated, and it is even more complicated when array reception is used.

For the traditional scheme of closed-loop clock when array receiving is used, each has its own disadvantages. If a single-channel signal is used for tracking, the signal of each branch is relatively weak, and it is difficult to achieve time slot synchronization; if the coordinated tracking of each branch signal is used, system is too complex

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