User Body Effect on Phased Array in UE for 5G mm Wave Communication System

Transcription

1 Forum for Electromagnetic Research Methods and Application Technologies (FERMAT) User Body Effect on Phased Array in UE for 5G mm Wave Communication System Zhinong Ying 1, Kun Zhao 1,2, Thomas Bolin, Jakob Helander 1,3 Daniel Sjöberg 3, Sailing He 2, Alessandro Scannavini, Lars J. Foged, Gross Nicolas 1. Network Technology Lab, SONY Mobile Communications AB, Lund, Sweden 2. Department of Electromagnetic Engineering, KTH Royal Institute of Technology, Stockholm, Sweden 3. Department of Electrical and Information Technology, Lund University, Lund, Sweden 4. Microwave Vision Group, Paris, France 1

2 Copyright The use of this work is restricted solely for academic purposes. The author of this work owns the copyright and no reproduction in any form is permitted without written permission by the author. 2

3 Abstract The latest study of the millimeter wave (mmwave) phased array in user device (UE) for 5G communication is presented in this paper. Particularly, the body effect on the phased array in mobile terminal at 15 GHz is investigated with the 3D measured data. Its impact on the recently introduced parameter for phased array in mobile terminal, the total scanning pattern, body loss and the coverage efficiency, is analyzed. Keywords: mmwave, 5 th Generation Mobile System, mobile terminal, phased array, body effect 3

4 Biography Zhinong YING is a principle engineer of antenna technology in the Network research Lab within the Technology Office, Sony Mobile Communication AB, Lund, Sweden, also as a distinguish engineer within the whole Sony group. He joined Ericsson AB in He became Senior Specialist in 1997 and Expert in 2003 in his engineer career at Ericsson. He served as TPC Co-Chairmen in International Symposium on Antenna Technology (iwat), 2007, and served as session organizer of several international conferences including IEEE APS, and a reviewer for several academic journals. He also has been a guest professor in the Joint research centre of Royal institute of Technology, Sweden and Zhejiang University, China since He is a senior member of IEEE. He was a member of scientific board of ACE program (Antenna Centre of Excellent in European 6 th frame) from 2004 to His main research interests are small antennas, broad and multi-band antenna, multi-channel antenna (MIMO) system, antenna for body area network, antenna and propagation in 5 th generation mobile network including massive MIMO and mm wave, near- field and human body effects and measurement techniques. He has authored and co-authored over 140 papers in various of journal, conference and industry publications. He holds more than 140 patents and pending in the antenna and new generation wireless network areas. He contributed several book chapters including Mobile Antenna Handbook 3 rd edition edited H. Fujimoto and Handbook of Antenna Technologies edited by Z. N. Chen. He had contributed a lot of work in antenna designs and evaluation methods for the mobile industry. He has also involved in the evaluation of Bluetooth Technology which was invented by Ericsson. He received the Best Invention Award at Ericsson Mobile in 1996 and Key Performer Award at Sony Ericsson in He was nominated for President Award at Sony Ericsson in 2004 for his innovative contributions. He received Distinguish Engineer title at Sony Group globally in

5 Towards 5G access technologies Which use cases are possible 2020? And which by 2024? > 1 Gbps > 5 Gbps High data rate Low latency High throughput Feature phone 384 kbps Smartphone 7-21 Mbps Smartphone/Tablet Cat3: 100 Mbps Bluetooth Profiles Notifier RSS, BT 3.0 Apps Data, Voice, GPS Standalone < 1 Mbps Signaling efficiency Low power Low data rate

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8 Ericsson 5G field trial UE reference unit BS UE 8

9 Sony devices were used in 5G field trials, Kista, Sweden 9

10 Major challenges in mmw mobile system Range Coverage: Need antenna array to have high gain in desired directions; Complex propagation environment; Beamfoming technology; Mobility: Directional array pattern, not ommi antenna coverage; Blockage from building and human body; Human being user cases including orientation and blockage uncertainty. Beam tracking in mobile cases. 10

11 To compensate the severe pathloss Smaller wavelength means smaller aperture for capture energy at antenna offset by an increment in combination of transmit power, transmit antenna gain, and receive antenna gain. PP RR = PP TT + GG TT + GG RR 20 log 4ππππ 20 log ff cc 3GHz->15GHz gives 13dB extra path loss due to aperture 11

12 Antenna array and array pattern In order to compensate the higher path loss without consuming more energy, high gain antenna array is necessary for both base stations and mobile terminals High Gain 850MHz cellular antenna Antenna Array Smaller electrical length in mmwave band, feasible for mobile terminals Narrow beam Space coverage turn to be much smaller comparing to current cellular antenna 15GHz four-elements antenna array Adaptive Phased array Hybrid array For mobility 12 Important to evaluate the performance of phased array in mobile terminal

13 Uniform Phase array has only limited scanning angle Uniform Phased array in mobile terminal is impossible to cover all angles. As the beam steering of phased arrays have a limited scanned angular range, it is important to characterize the achievable space coverage of such a system 13

14 Total scanned pattern Total scanned pattern: The total scan pattern is regained from all array patterns corresponding to different phase shifts, by drawing out the best achievable gain at every angular distribution point (θθ, φφ)

15 Coverage Efficiency Coverage Efficiency reflect part of the mobility (rotation and orintation): The coverage efficiency is the ratio between coverage area and the total area. ηη cc = CCCCCCCCCCCCCCCC AAAAAAAA TTTTTTTTTT AAAAAAAA The coverage area can be defined as the total scan pattern coverage with respect to a threshold gain level. The total area includes the whole surrounding sphere The threshold gain will depend on the path loss, transmitting/receiving power level and transmitting antenna gain [1]Helander, J., K. Zhao Sjöberg, D., Gustafsson, M., and Ying, Z. Characterization of mmwave Phased Array Antennas in Mobile Terminal or 15Station for 5th A Generation Mobile System, IEEE Antennas EMB antenna Wireless 2016 Propag. Lett., in press

16 Array Design Example: Uniform Notch antenna array A eight elements notch is proposed: Each four elements compose a sub array Two sub array exist in the phone and operate separately Supporting both MIMO and Diversity scheme 16 Simulation and measurements agrees well.

17 Notch Array Design Sub array 2 Sub array 1 Two groups of phase shifter are connected to the antenna elements, each phase shifter can vary from -180 to 180 Phase Shifter Phi1 2*Phi1 3*Phi1 4*Phi1 Phi2 2*Phi2 3*Phi2 4*Phi2 Phi1= 0 Power Input Power Input 17

18 Different antenna arrays are built and tested in tablet phone mockup 4x1 linear array with ½ wave space 18

19 Three test cases, the real person performances were measured also. All measurements were carried out in SATIMO system in Microwave Vision Group Lab in Paris, France. 19

20 Example: the notch antenna array in three different test cases Above column are element patterns, and bottom column are 4x1 array scanning patterns. Body shadowing is obvious, human body reflection results more directive pattern! 20 A EMB antenna 2016

21 Different Antennas: efficiency and real body effects Notch Slot Mesh-Grid Patch Free space -0.2 db -1 db -0.5 db Data mode -0.5 db -2.5 db -2 db Talking mode (body worn) -2 db -3.5 db -2.2 db Body loss is much less comparing with the Gigaherze cellular bands! 21

22 Three antenna arrays coverage efficiency in free space and data mode LOS NLOS Body blockage reduce CE nearly 20% in LOS, But not much change in NLOS cases! 22

23 Three antenna array coverage efficiency in free space and talking mode(body worn) LOS NLOS Body blockage and body loss reduce CE nearly 40% in both LOS and NLOS cases! 23

24 Sony terminal with a hybrid array in Ericsson 5G field trials in Kista, Sweden 100MHz 200MHz Reference and Sony antennas have similar performance! Ericsson reference antenna

25 Conclusions The coverage efficiency and total scanned pattern are defined to evaluate the mmwave phased array in UE in 15GHz for 5G communication. Antenna array in phone mockup and real human body effect were evaluated. Antenna element pattern and array topology will affect the coverage and mobilitys. Body shadowing is obvious, human body reflection results more directive radiation pattern. Body loss is much less comparing with the Gigaherze cellular bands. In browsing mode, body blockage reduce CE nearly 20% in LOS, but not in NLOS cases! In body close cases, body blockage and body loss reduce CE nearly 40% in both LOS and NLOS cases due to directive patterns. 25

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