Research On Wireless Laser Communication Transceiver Technology

Wireless laser communication is the process of information which is transmitted to be modulated to the laser beam. Then, it implements the process of information delivery by transfering and recieving the laser beam. Wireless laser communication has many advantages, mainly in big channel capacity, good confidentiality, unrestricted constraint and easy installation works and so on. Therefore, it is widely used for LAN interconnection, smart cities, satellite communications of military secrecy line and other aspects. This paper focuses on investigating wireless laser communication data transceiver technology, and designs a wireless laser communication system in line with real CS laser gun performance requirements.This paper introduces the basic concepts about wireless laser communication systems, deeply making a study of wireless laser communication system of composition principle and related technologies. And propagation property of the laser in atmospheric channel is also studied. Then it proposes a coding scheme basing on grasping Turbo coding theory, and provides the corresponding simulation. Next, the paper discusses the laser source working principle of laser light emitting subsystem, laser alignment technique, laser drive circuit with power automatic compensation function, photodetector working principle of the light receiving terminal and signal amplification circuit and so on. On the basis of mastering these key technologies and refering to predecessors' mature optical fiber communication scheme, the paper offers a laser communication system designed by a way of the intensity modulation-direct detection. In the program, the transmitter of the system gets the laser light source to be drived and modulated by selecting laser driver chip MAX3263, and achieves transformation of the electro-optical signal by red wavelength semiconductor laser. The system receiver selects PIN photodiode to obtain photoelectric conversion and chooses the chip MAX3760 and MAX3762 to achieve low power transimpedance preamplifier and limiting amplifier functions. In addition, the design will also make an alarm if the light is weak from the laser light source. Finally, the system is tested by waveform and the test results is analyzed.