The Design And Implementation Of Frequency Scheduling And Control System

With the advantages of far transmission distance, simple structure and indestructible propagation medium, short-wave communications is wide ly applied in military and emergency communications. The frequency of short-wave signal transmission varies from 3 to 30 MHz, and different frequencies have different transmission quality, so the design and implementation of short-wave radio frequency scheduling and control system has been a hot research field of communications all the time.The frequency scheduling and control basing on the short-wave communications is achieved in this paper, namely selecting the appropriate frequency of completing the optimal transmission short-wave signal. Frequency scheduling and control mainly includes two aspects: firstly, the optimal frequency in a number of frequencies is selected for data transmission before transmitting data; secondly, when the current channel quality is unsatisfactory, the frequency is changed for optimal data transmission. To achieve the functions above, the paper includes three parts.The first part mainly introduces the theoretical basis of short-wave radio station and the development of short-wave communications, including the short-wave radio network architecture, protocol architecture, and channel mode. According to the current network transmission environment, this paper analyzes that the network architecture and channel mode are good for the current network, and researches on the current network environment to draw the existing problems of the frequency scheduling and control; The second part puts emphasis on the design of the short-wave radio frequency scheduling and control. Five system working status, which includes the initial network, link detection, data transmission, late network and frequency shift, are purposed in this paper b y the functional division of shortwave radio communication system, and a detailed scheme design is achieved successively; By utilizing the system controller to track the entire system debugging process, the third part verifies that frequency is scheduled and controlled successfully in the software and hardware platforms of short-wave radio communication system, and puts forward the corresponding solutions of the main problems during the debugging process.Ultimately, in the current transmission environment, all sites achieve the optimal transmission of short-wave signal, and the frequency scheduling and control of short-wave radio communication system is finished successfully.