| Along with the development of technology, wireless communication system gets widely used. Comparing to the RF system, IR system has following advantages: IR does not need to apply for the frequency; it can provide security communication because of its anti listening charateristic. But limited by the power of IR transmiter, IR wireless system could only be used in the room or other small area. Short communicating distance is the bottleneck of the IR communication system's development.To improve the communicating distance of IR system, the author propose a scheme that apply IR Laser Diode in the IR system. The dissertation puts emphasis on the hardware platform building of IR Laser Wireless Communication System on the physical layer, driver programming base on ARM7, supporting program designing on the applicating layer, and design Long Distance IR Laser Wireless Communication System combinded with Bluetooth, Wifi technololgy.First, the dissertation formulates the general blue-print and computing the maximum communicating distance in theory. To adapt the instant strong current in LD working, designing the modulating wave generation circuit which could adjust frequency and duty factor; designing the signal control circuit with dynatron which could resist strong current; designing ARM master board which could generate 1.5A current; and designing the PCB to make the system work stably.Second, in system software designing, carring out the efficient ARM drivers programming to control the system with the interrupts; due to PDA device could not resist the strong environment RF disturbance, designing a custom protocol to provide accurate communication.Finally, in order to confirm system performance, carring out plenty of test, including key module test and system test. The system achieves 100m in test, and work stable.The research in the dissertation is a good attempt for IR transmission theory. The design for the IR system also has it market prospect. |
PDF Full Text Request