Optimization of handover measurement procedure for TD-LTE networks in mountainous scenario

摘要

Handover (HO) is a key procedure in long term evolution (LTE) systems. This paper makes a detailed introduction on two aspects in HO measurement procedure—Layer3 filtering theory and the radio link failure (RLF) procedure. As the channel environment in mountainous scenario has a great effect on received signal, we have made researches and optimizations on user equipment (UE) measurement signal accordingly. HO procedure based on Layer3 (L3) filtering and optimized RLF procedure are designed and implemented in a dynamic system level simulation platform which models the mountainous scenario. The UE measured Reference Signal Received Power (RSRP) of source and target eNodeB with different L3 filtering factor have been measured to make a comparison and select the best one. Ping-pong HO rate and RLF rate are used to evaluate the influence of L3 filtering to HO performance. Simulation results show that the best L3 filtering factor is 1/6 and the optimized RLF procedure is effective in mountainous scenario. The paper presents a new fast interpolation method based on edge extraction. Our method extracts image edge by improved canny operator which has two specified thresholds first. Then for different areas, it chooses different methods. It can keep edge details while doing quick interpolation. The experimental results show that the effect of this method can hold the edge details very well, and it is obviously superior to the traditional ways. The method provides a better initial image for the super resolution reconstruction.