Evaluation on Doppler Spread Based Mobile Terminal Velocity Detection Using Practical Radio Propagation Data in Presence of Moving Scatterers

摘要

In layered cellular networks with small cells densely deployed into macro cell area, to improve frequency utilization while avoiding the frequent handovers (HOs) that occur between small cells when a high velocity mobile terminal (MT) travels through these small cells in a short period of time, an inter-layer HO control policy that MTs traveling at a high velocity are served by the macro-cell layer and MTs traveling at a low velocity are served by the small-cell layer, has been receiving attractive attention. To realize such inter-layer HO control policy, MT velocity detection techniques are essential. The authors investigate a Doppler spread based MT velocity detection scheme for MTs where the GPS function has been manually disabled by the user as well as for MTs without the GPS function. This paper first evaluates the performance on a Doppler-spread based MT velocity detection algorithm with the use of practical outdoor radio propagation data. Then, from the evaluation results, it is considered that the presence of moving scatterers may degrade the detection accuracy. Finally, this paper proposes a scheme to suppress the velocity detection error caused by moving scatterers and the proposed scheme is evaluated using actual outdoor measurement data.