Free Space Optical Communication Systems

Free-space laser communication as a new technology has been developed for more than thirty years. Recently, the free-space laser communication has achieved a great progress as the development of the semiconductor technique and optical fiber communication. The free-space laser communication has a good performance in data security and capacity, which will be a good choice in communication or as the complement of other communication method. In this dissertation, the basic principle on the free-space laser communication field is introduced. And a general analysis was taken on the space channel effect to the communication signal. The main work of this dissertation is to design a video transmission hardware system based on the CPLD by using the PPM (Pulse Position Modulation) which will cooperate with the receiver to achieve the free-space laser communication. In the design, the MAX3000A series CPLD from the Altera Corporation is adopted. The communication system increases the distance of the free-space laser communication in some degrees.