Analysis of Path Prediction Error for a High-Mobility Massive MIMO-OTFS System

In the next generation mobile network, the communications in high-mobility environment is an important topic with the development of many new scenarios e.g., autonomous vehicles, high speed train, etc. The orthogonal time frequency space (OTFS) has been a promising way to study those high-mobility uses, especially for the implementation of massive multiple input multiple output (MIMO) communication systems. In this paper, we study a path prediction scheme for massive MIMO-OTFS system. In a high-mobility environment, the spatial information of the channel is critical. Most of the existing work on estimating or predicting the spatial information lacks analysis of how the results of the spatial information acquiring, e.g. path prediction, can affect the performance of the communication system. In this paper, a path prediction method is proposed to study the path appearance and disappearance. Our analysis indicates that detection of non-existing path/s deteriorate the system performance more in terms of bit error rate (BER) comparing to the ignorance of existing path/s. A confidence factor is then introduced in the prediction scheme to mitigate the performance loss. Simulation results demonstrate that the confidence factor can effectively decrease the BER by 10%.