Location Discovery and Error Analysis of Wireless Sensor Networks Based on Difference of Arrival Time of Beacon Signals

Nodes of wireless sensor networks are characterized with energy constraint, difficult to implement time synchronization, random deployment etc. Range measurement and location discovery principle of several methods, such as RSSI, ToA, TDoA and AoA are briefly introduced. Afterwards, a novel location discovery algorithm which is based on difference of arrival time of beacon signals is proposed. There is no requirement of time synchronization among anchor nodes and target nodes. Also, no additional equipment or circuit is needed. Particularly, error of location discovery is analyzed when anchor nodes are placed in the form of equidistant right-angled triangle. According to the expression of error, accuracy of location discovery can be improved through enlarging the distance between anchor nodes and enhancing clock precision of target node.