Wireless Audio Sensor Network And Node Design

Recently, more and more research is focused on the application of WSN in audio and video signal processing both at home and abroad. This thesis analyzes the WSN architecture in details and designs a wireless audio sensor network platform based on sound collection.It presents a self-organizing network of multi-node tree structure, as well as a compatible network monitoring system.Firstly, the thesis analyzes the WSN architecture in details, including network structure, hardware structure of nodes and the network protocol stack structure. MAC protocol, routing protocol and time synchronization mechanism are also researched.The thesis analyzes the architecture of wireless audio sensor nodes in details and introduces the detailed design of each hardware module based on the ATmega128L and CC2420 platform, especially the sensor board module. How to choose the audio sensor and the design of audio signal processing circuit are provided. Additionally, this thesis realizes a serial port and the detection of the battery's remained energy.The thesis also analyzes the WSN protocol stack in details and improves the former protocol stack based on IEEE 802.15.4. It introduces the design process of each layer, mainly including the hardware drivers and the data receiving function in the physical layer, the CSMA/CA mechanism in the data link layer, an improved routing protocol based on the minimal jump times, the processing of collected data, as well as an improved time synchronization protocol based on DMTS.In the end, simulation and tests of the audio sensor board are carried out. The results indicate that the nodes can work steadily and sound collection can be accomplished in practice. The thesis also tests the routing algorithm. The results show that all nodes can achieve routing establishment based on the designed routing protocol and periodically collect and transmit audio data, by which further research and application with practical sound localization can be achieved.