Cell discovery is the procedure in which a user equipment (UE) finds a suitable base station (BS) to establish a communication link. When beamforming with antenna arrays is done at both transmitter and receiver, cell discovery in mm wave systems also involves finding the correct angle of arrival - angle of departure alignment between the UE and the detected BS. First, we consider the single BS scenario and present the mathematical model for the cell discovery problem. We present the details of the beam sweeping based techniques and explain the beam combining scheme to reduce the training overhead. We analytically characterize the performance of energy detector at the UE for both beam sweeping and beam combining methods under some channel assumptions. Further, we consider the multiple BS case where BSs transmit synchronization signals along with directional beamforming. We analyze the performance of the energy detector in this case as well. We finally present simulation studies with channels generated using generic mm wave channel emulators and draw inferences on the role of various parameters on the cell discovery performance.
翻译:细胞发现是用户设备(UE)找到合适的基站以建立通信连接的程序。当发射机和接收机都使用天线阵列进行射线成形时,毫米波系统中的细胞发现也涉及寻找正确的抵达角度----UE和检测到的BS之间的离心调整角度。首先,我们考虑单一的BS情景,并提出细胞发现问题的数学模型。我们介绍了光谱扫瞄技术的细节,并解释了降低培训管理费的光束组合计划。我们分析地说明了UE的能量探测器在光谱扫瞄和光束结合方法方面的性能。此外,我们考虑了多个BS案例,即BS将同步信号与方向波束相传送。我们分析了这个案例中的能量探测器的性能。我们最后对使用通用毫米波道模拟器生成的频道进行了模拟研究,并对细胞发现性能的各种参数的作用进行了推断。