This paper proposes a compact interpolation scheme dedicated to a 1-dimensional position sensitive detector (PSD) with an optical sensing pixel array. The pixels are divided into even- and odd-numbered groups and winner take all (WTA) circuits are provided to each of the groups. The simulated results show that the detecting step-width is reduced to the half of the original one after applying the interpolation scheme.

Uncertainty within one-wavelength (λ) is inevitable in an ultrasound positioning system that measures the time of flight of ultrasound pulses especially when a simple comparator is used for pulse detection. This paper proposes a compensation scheme based on pulse period adjustment. The test results show that the proposed scheme efficiently eliminates the 1λ-deviation and provides improved distance measurement.