Abstract: Geofencing is becoming more and more important, and there is a lack of standards or metrics to evaluate whether an application is designed appropriately and performs well enough. In this research, an application is built to test about functions of geofencing in Android OS, and it is also a tool for assisting the evaluation of performance. Three performance metrics, namely power consumption, accuracy and responsiveness, are studied. To study the power consumption, an indirect approach is adopted, which is measurement of power endurance of the devices, instead of direct measurement of actual power consumption by the application. Field testing is used to study the accuracy and responsiveness of the application. The test is performed in the format that testers bring along the device, which has the testing application being installed, to walk through a path going through fences’ boundaries which are set before testing. Different location services are enabled and disabled alternately and rep

• Publication Date: 27-Aug-2014
• DOI: 10.15224/978-1-63248-024-8-20
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Abstract: We consider LTE-Advanced uplink system where user equipment (UE) transmits its data to eNodeB. In the uplink system, demodulation reference signal (DM-RS) is transmitted for the channel estimation on the center symbol of the resource block allocated to the UE. Also, sounding reference signal (SRS) is transmitted on the last symbol of the resource block periodically. In this paper, we propose an improved channel estimation scheme by using the SRS: lease square (LS)-based scheme. Simulation results show that the proposed channel estimation scheme has better performance than the DM-based conventional scheme.

• Publication Date: 27-Aug-2014
• DOI: 10.15224/978-1-63248-024-8-21
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