Development And Application Of An Adaptive Hopping Frequency Wireless Communication Platform

With the development of Wireless Personal Area Network (WPAN), the application area of it has been becoming wide and wide. Wireless Distributed Sensor/Control Network (WDSCN) is one of the applications of WPAN in automation area. There are many ways to establish WPAN such as IrDA, Bluetooth, HomeRF, UWB and RF. By comparison and analysis and according to the characteristics of WDSCN, a project based on the Radio Frequency (RF) is presented, and an adaptive, frequency-hopping wireless communication platform is developed.The function of each module in the system is introduced in details, followed by its implementation techniques.(1) The selection of MPU and its function implementation. The microprocessor selected in the system is a kind of 16-bit MSP430 FLASH series of TI company. And the main function of it is to get the control of the RF module and collect data from all kinds of sensors.(2) The design of RF module and its realization. Being compared with other common RF chips, nRF903 is chosen to fulfill short distance wireless communication in ISM band.(3) The control of data collection module for sensors and its achievement. A fast 12-bit analog-to-digital converter (ADC12) built in the MPU is used to sample the data from the external and inner sensors.(4) The control of monitor module for camera sensor and its fulfillment. Real-time image data is collected from camera sensor controlled by MPU.(5) The design and accomplishment of Host control module.Data encoding and error control are very important in wireless communication. Comparative analysis is made on the data encoding and the realization of data encoding methods used in this system is presented. As to the error control and data correction, the parity check and hamming code check solutions are provided also to guarantee the reliability of data transmission and improve the anti-jamming capability of the system.Combining with concrete example, a small scale star topology WPAN built withthe wireless communication modules is introduced in this paper. A host, a base station and some terminals is applied in this WPAN. The communication mode between base station and terminals is point to multi-point (PMP). The communication protocol between base station and terminals and its implement and the adaptive hopping-frequency method to avoid disturbance of them is introduced in detail. Data are exchanged between host and the base station through serial port. The host disposes with data and takes charge of the whole WDSCN by the application software.This wireless communication platform can be widely used in intelligent monitoring, wireless data collection, wireless label, identity acknowledgement, alarm and security system, wireless digital voice and digital image transmission and so on, and shows promises of a splendid application future.Based on the summaries and conclusions of all research works, some suggestions and prospects for further researches are put forward.