Abstract:
A wireless sensor network is a network of sensors that transmits information wirelessly back to a controller. It provides a powerful tool for the monitoring of conditions in a large area via any number of sensor nodes. Traditionally such a network is limited to receiving information passively from the sensors, but with the progress of technology, wireless sensor networks have become increasingly powerful. The advances in electronic miniaturisation and wireless communications have extended the ability of the network controller node to communicate and thus regulate the activities of the sensor nodes. This has opened up a diverse range of possible applications for wireless sensor networks. The key to the functions of a wireless network lies with the wireless communications system. The transceiver controls the transmission of information on the one hand, while serving to capture and make sense of transmitted information on the other. Thus a low power consumption transceiver design based on the modulation technique of binary phase shift keying, has been developed. Furthermore, to analyse the performance of the designed system, models of the communications environment is developed. Based on the type of environments under which wireless networks could be expect to operate, an additive white Gaussian noise model of the channel and a Rayleigh flat fading model has been developed. The proposed transceiver is evaluated within this modelled environment and shows promising results in terms of accuracy and transmission speed. Base on the success of the design in software based modelling, the proposed transceiver is then implemented on a hardware level using field-programmable gate arrays and the VHDL hardware description language. The resulting system is also analysed using models of the environment, and produced satisfactory performances.
