RSS-Based DoA Estimation Using ESPAR Antenna Radiation Patterns Spline Interpolation

In this paper, it is shown how power pattern crosscorrelation (PPCC) algorithm, which relies on received signal strength (RSS) values recorded at electronically steerable parasitic array radiator (ESPAR) antenna output port, used for direction-of-arrival (DoA) estimation, can easily be improved by applying spline interpolation to radiation patterns recorded in the calibration phase of the DoA estimation process. The proposed method allows one to measure ESPAR antenna's radiation patterns during the initial calibration phase with much coarser angular resolution than required for linearly interpolated radiation patterns. Simulation results indicate that the overall DoA estimation accuracy can be kept at the similar level even for a few number of points, which, when applied in anechoic chamber calibration procedure of wireless sensor network (WSN) nodes equipped with ESPAR antennas, will have a noticeable influence on the overall calibration time and therefore also on deployment costs in practical WSN applications.