A downlink user speed based scheduling algorithm for mobile systems with time multiplexing pilot

In mobile communication systems, high speed users usually need better channel tracking ability than low speed users. However, the current scheduling algorithms ignore the difference of the channel tracking ability among data channels. In this paper, a novel scheduling algorithm is proposed for mobile systems with the time multiplexing pilot. At first, the Cramer-Rao Bound of channel estimate is derived and a dramatic difference in tracking ability among different data channels is found. Then, a novel scheduling algorithm based on users' moving speed is proposed. The main idea of the proposed algorithm is to assign the data channels close to the pilot to high speed users, while the data channels far from pilot to low speed users, thus providing almost identical channel estimation performance. Simulation results show that the tracking ability of the assigned data channel perfectly matches the user's moving speed and good scheduling fairness is also achieved simultaneously.