Speed estimation in uplink frequency domain for mobile OFDM systems

The speed of user equipment (UE) is significant in improving the performance of orthogonal frequency division multiplexing (OFDM) systems. Estimating the speed can help in adaptively allocating resources to users, reducing call drop rate in handoff, selecting the optimal radiation pattern, etc. The Doppler spread caused by the relative movement between transmitter and receiver can be utilized to estimate UE speed. Many Doppler spread estimation algorithms have been studied in recent years, such as zero crossing rates (ZCR) algorithm, level crossing rates (LCR) algorithm and autocorrelation function (ACF) algorithm. In this paper, we propose a novel speed estimation method for mobile OFDM systems based on autocorrelation function, where UE speed is estimated in uplink frequency domain on the base station (BS) side. Simulation results demonstrate that the proposed method can estimate UE speed accurately and is more robust to noise.