Short-Time and Adaptive Controllable Spot Communication Using COTS Speaker

This paper proposes a spot-communication method that can direct the spot to the user location adaptively. In the proposed method, the first transmitted signals are used to estimate user location, which is then reflected in the second transmitted signals; therefore, the spot directed to the user can be generated instantaneously. As the signals consist of mutually orthogonal sinusoidal waves, multiple spots can be generated simultaneously, and the shape of the spots can be controlled by overlapping them. Through real environmental experiments using four speakers, we confirmed that our proposed method can generate adaptive spots. Moreover, in the case that appropriate spots were not generated, comparisons were carried out with respect to the theoretical values to determine the cause.