Design And Implementation Of AES Baseband Signal Mobile Monitoring System

With the development of the radio station digital and networked process, AES baseband signal has become the mainstream in the radio broadcast transmission network. In the broadcast transmission network, the state change of AES signal often cause the bad audio index, unstable system, even off the air. Therefore, in order to realize the high quality and safety broadcasting of radio, an effective monitor of AES baseband signal is the urgent need.According to the radio station requirements to AES baseband signal monitoring and alarm, we analyzed the existing audio monitoring system; and discussed the parameters that must be monitored in the audio monitoring system; furthermore, we researched the network transmission technology and the Android development technology. Directed at the existing monitor has certain limitations of location, we designed a set of monitoring system based on Android platform, the system achieved real-time monitoring and convenient monitoring for AES baseband signal; the specific work and innovation are as follows:1. The design of data measurement Analyzed the common audio signal amplitude, loudness and phase measurement method, using the algorithms meet the accuracy requirement of monitoring on the audio and the real-time demand, realized the loudness, amplitude and phase measurement of the audio signal.2. The design of network transmission Designed a set of simplified application layer real time network transmission control protocol, designed the data frame format and the transmission control algorithm. Through a unified interface forms, hierarchical completed the three types data transmission of control instruction, measurement data and audio. In the transmission of measurement data, checking mechanism and retransmission mechanism is introduced to eliminate the packet loss and the influence of the error packet, make the measurement data correctly and timely transmitted to the monitoring equipment, ensured the reliable alarm of system; At the same time, in the transmission of audio data, congestion control algorithm was designed, through the feedback system, using the additive adding additive reduction strategy dynamically adjust the rate of transmitting audio stream, can effectively to control the audio stream transmission on network congestion situation, ensured the real-time monitoring function.3. The design of monitoring As a result of the large number of monitoring indicators, and at the same time need to monitor multi-channel of audio, the monitoring system need to time process and display of large amount of information per unit, however the mobile terminal has limited processing capacity and its screen size is usually smaller. To solve this problem, at the same time, provide users with a friendly interface and simple operation, we use the combination of background services and multi-thread programming technology, and optimize the graphical display algorithm, improved the utilization ratio of resources and reduced the resource usage, page caching mechanism is used to speed up the operation, and eliminate the phenomenon of the page stagnation; At the same time, the use of multiple pages to graphical display the monitoring results, make the space of the graphical display adaptive to the size of the screen, and used the multi-touch to realize zoom in and zoom out, to facilitate users to view.