Abstract：The 5G millimeter wave(mm-wave) technology provides abundant frequency resources and high throughput, but due to its severe path loss and penetration loss, the millimeter microwave cellular system must adopt high directional beamforming transmission technology when performing cell search and synchronization processes.Based on the improvement of the delay in the directional transmission process, this paper adopts an improved cell discovery algorithm based on the traditional algorithm. The algorithm improves the cell discovery process and reduces the delay by using the background information through the hybrid network architecture of the control plane and the user plane. The experimental results are obtained by MATLAB simulation test: the transmission delay of the improved algorithm is reduced by 40% compared with the traditional algorithm.

Abstract：In this paper, the four-unit high-isolation mobile phone antenna is composed of four radiating elements, and the radiating elements are located at four corners of the antenna. The antenna radiating unit is analyzed and tested, and the operating frequency band of the antenna radiating unit is measured from 3.43 GHz to 3.86 GHz, covering the 5G mobile communication test frequency band. The working frequency band of the MIMO antenna is 3.45 GHz～3.64 GHz under the condition that the port return loss is less than -10 dB impedance bandwidth, and the antenna working frequency band is 3.23 GHz～3.96 GHz under the condition that the port return loss is less than -6 dB impedance bandwidth. The newly designed circular slotted structure reduces the coupling of antennas and electronic components, and the antenna has good omnidirectional and radiative characteristics. The MIMO antenna has a radiation efficiency of 65%～73.4% at 3.2 GHz to 4 GHz. The simulated brain radiation SAR(specific absorption rate) parameters are less than 1.6 W/kg, and the antenna has a low impact on the human body.