Antenna Controller for Low-latency and High Reliability Robotic Communications over Time-varying Fading Channels

In this paper we consider the problem in which a single antenna mobile robot (MR) is required to maintain reliable communication with a base station (BS) while following a given trajectory. The wireless communication channel is assumed to experience time-varying small-scale fading with time-varying coherence time. To achieve high reliability and low latency of the communication link, compensation for the small-scale fading is required. Since the MR has to stay on the predefined trajectory, we propose to compensate for the fading by continuously adjusting the position of the antenna on a revolving platform on-board the MR. This is done by a closed-loop antenna controller which optimises the position of the antenna at all times without modifying the trajectory to be followed by the MR. Results show that this technique can effectively compensate for the small-scale fading without introducing delays in data reception.