No abstract

No abstract

Device-to-device (D2D) communication enables nearby user equipments (UEs) to communicate directly without passing it through a base station (BS). When UE wish to communicate over direct link it is required to know the channel condition of its D2D link and its cellular link to select a link providing the best quality of service, so-called mode selection. UEs participating D2D communication need to conduct measurement over its UE-UE link and its eNB-UE link as well, and BS makes decision on mode switching based on the measurement report of UE. In this paper, we study the measurement procedures and reporting algorithms required for D2D communication. Frequent measurement report can cause the ping-pong mode switching whereas infrequent measurement report results in the delay of mode switching, thereby, leading to losing opportunity to offload traffic from the network. Wasteful frequent ping-pong mode switching is observed in some cases. We show that our proposal prevents frequent ping-pong mode switching without significant degradation in offloading performance achievable from D2D communication.

A dual-polarized small base station antenna with a dielectric feeding structure is presented. The proposed antenna is composed of a micro-strip feed line board, eight metallic shorting plates, four dielectric feed substrates, four metallic radiators, a metallic cube, and a radome. A wide impedance bandwidth of 20% (2.45 to 3.0 GHz) is achieved. The proposed antenna has an isolation of greater than 50 dB over the operating bandwidth. Details of the proposed antenna design, and the simulated and measured results are presented and discussed.

No abstract