RSSI Estimation for wireless sensor network through-the-earth communication at frequency 433 MHz

摘要

To explore wireless sensor network signal transmission characteristics in through-the-earth communication, this paper focused on wireless network signal transmission attenuation by using 433MHz carrier frequency. Sensor nodes electromagnetic wave transmission characteristics were studied under the condition the different receiving node height, horizontal distance between the transmitting node and the receiving node through the wheat field experiments and computer simulation, the relationship between the received signal strength was established, transmission characteristics of field soil information collection sensor nodes in the soil under four wheat stages were put forwarded. The experiment demonstrated that 8 model goodness of fit R-2 of effection of receiving node high and inter-nodes horizontal distance on RSSI(Received Signal Strength Indicator). Besides, three-dimensional surface of RSSI was built in four wheat growing periods, which the fitting model and goodness of fit of RSSI are obtained, and the model verification was conducted through SPASS software. Validation results showed that the model could better predict the received signal strength at different condition through-the-earth communication. The study can provide the technical support for sensor network node deployment and the establishment of the system in soil information acquisition.