Generalized Vernier Effect and Its Application for RF Propagation Time Measurement

Abstract

In wireless sensor network systems, localization of sensor nodes has been required, since positional information of sensing values can be used for many purposes. Consequently, range measurement, i.e. propagation time measurement technique has been demanded, in order to obtain accurate distance between sensor nodes. In this paper, novel RF propagation time measurement method has been proposed. This method employs two heterogeneous operation clocks, and based on basic or generalized vernier effect, it generates new virtual time resolution which is much finer than unique time period of operation clocks like vernier caliper. Concretely, when RF communication is performed between transmitter and receiver by using heterogeneous operating clocks each other, duplicated transmission of RF impulse signals has made up particular impulse receiving pattern which depends on amount of RF propagation time. Proposed method has been installed to experimental RF sensor nodes, and its validity has been confirmed. As a result, improved time resolution, that is, precise propagation time measurement has been realized by evaluating RF impulse receiving pattern.