Challenges of 5G mmwave RF Module. Ren-Jr Chen M300/ICL/ITRI 2018/06/20

Transcription

1 Challenges of 5G mmwave RF Module Ren-Jr Chen M300/ICL/ITRI 2018/06/20

2 Agenda 5G Vision and Scenarios mmwave RF module considerations mmwave RF module solution for OAI Conclusion 2

3 5G Vision and Scenarios 3

4 5G Vision and Scenarios Source: Qualcomm, Challenges and Design Aspects for 5G Wireless Networks 4

5 mm-wave: a sure solution for 5G 5

6 Candidate higher bands in WRC-15 & FCC Source: Huawei, D.Soldani 6

7 mmwave RF Module Considerations 7

8 Microwave vs. mmwave: Antenna and RF front-end Effective area: l 2 /4p d Rx mmwave aperture Cell edge UE Cell edge mmwave beamforming UE Isotropic Tx Sphere area: 4pd 2 Microwave aperture BS Micro-Wave single antenna BS Micro-Wave single antenna mmwave single antenna mmwave single antenna Beamforming weight Up-converter DAC DAC 8

9 Beamforming architecture selection All digital vs. hybrid beamforming: DAC DAC DAC DAC DAC All digital beamforming Hybrid beamforming 12bits x 2(I/Q) x 250MHz x 64 elements= 384Gbits/s Beamforming weight Up-converter Hybrid beamforming architectures may be a good choice by trading-off power consuming, cost and complexity. 9

10 Rank Issue in beamforming DAC ADC DAC BF h 11 h 21 h n1 h 12 h 22 h n2 h 1m h 2m h mn rank? ADC Spatial Multiplexing MU-MIMO in same beam MU-MIMO in different beam 10

11 Polarization in beamforming Polarization could help the rank condition in two layer beamforming DAC DAC DAC DAC Beamforming weight Up-converter Two layers with polarization may be a good choice in mmwave band when using beamforming 11

12 CP1 CP1 CP1 CP1 CP0 CP1 CP1 CP1 How fast we need? 1 frame = 10 subframes Subfram 0 Fast beamforming capability 1 radio frame = 10 ms Subfram 1 Subfram 2 Subfram ms 1 subframe = 8 slots Slot 0 Slot 1 Slot 2 Slot 3 Slot 4 Slot 5 Slot 6 Slot ms ms ms ms slot = 14 Symbol 0 OFDM symbols ms ms ms Symbol Symbol ms ms ms Symbol slot = 14 OFDM Symbol 1 Symbol 1 Symbol 2 Symbol 13 symbols ms ms ms ms ms ms 12

13 Phase noise issue At carrier in higher frequency, phase noise becomes significant and could result in performance degradations RF Antenna Elements D/A RF Antenna Elements x N x N Oscillator x N x N D/A RF Antenna Elements RF Antenna Elements Consider PN issue in spec. design

14 mmwave RF module solution for OAI 14

15 5G mmwave platform 15

16 Function block of platform M 3 FORCEC-C1056A 1GB DDR3 USB JTAG TX1 RX1 1Gbps Ethernet Kintex-7 FPGA XC7K325T AD9361 RX2 TX2 mmwave Module SYNC OUT SYNC IN CLK OUT CLK IN Clock board VCTCXO Mmwave DCI Power 16

17 Hardware spec. RF part (M 3 FORCEC-C1056A) 2x2 MIMO, Support band: 70 MHz to 6.0 GHz Bandwidth: 200kHz to 56 MHz AD/DA: 12 bits TX EVM: 40 db TX noise: 157 dbm/hz noise floor TX monitor: 66 db dynamic range with 1 db accuracy 17

18 Mmwave module 28GHz antenna phased array system (gnb) specifications Frequency band:27.5ghz~28.3ghz 4 x 4 (or 4x2) antenna array EIRP: 4x2 case H:~29dBm, V:26.3dBm Dual polarization with same antenna 2-stream Horizontal field of view:120 degrees Vertical field of view:120 degrees Total 8 fast beam tables 18

19 Phased Array Configuration 4x2 Phased Array 4 4 Phased Array 1.8 VDC 1.8 VDC 1.8 VDC DCI Bus DCI Bus DCI Bus H V H V 19

20 WB /Phase C0 C1 C2 C3 R R R R Ideal Beam Pattern & Beam Tables for 4-by-4 module Phi=0 Horizontal Beam NB0 /Phase C0 C1 C2 C3 R R R R NB1 /Phase C0 C1 C2 C3 R R R R NB2 /Phase C0 C1 C2 C3 R R R R Phi=90 Vertical Beam NB3 /Phase C0 C1 C2 C3 R R R R Spherical Coordinate 20

21 WB /Phase C0 C1 C2 C3 R R Ideal Beam Pattern & Beam Tables for 2-by-4 module Phi=0 Horizontal Beam NB0 /Phase C0 C1 C2 C3 R R NB1 /Phase C0 C1 C2 C3 R R NB2 /Phase C0 C1 C2 C3 R R Phi=90 Vertical Beam NB3 /Phase C0 C1 C2 C3 R R

22 3-D far-field pattern 22

23 Far-field patterns of LTCC antenna array 23

24 Input Power vs. EIRP 4 2 LTCC Phased Array Module 45 Horizontal Polarization 50 Vertical Polarization EIRP (dbm) Measured EIRP 29 dbm EIRP (dbm) Measured EIRP 26.3 dbm Input Power (dbm) Input Power (dbm) 24

25 Phase noise performance 28GHz distributed LO INT INT frequency)=-33.5dbc 25

26 Beamforming capability Mmwave communication Very fast beam control: stable time ~140 ns Measure mmwave channel Develop beam calibration algorithm 26

27 CP1 CP1 CP1 CP1 Beamforming control (case 1) More about beam control Data in FPGA Symbol 1 Symbol 1 Symbol 2 Symbol 13 Beam control in FPGA ms ms ms ms ms ms 0.140µs Beam index timing Beamforming control (case 2) 27

28 28 Key feature Matlab based design very easy to use Provide matlab API and matlab example codes Very robust and accuracy clock board: Initial Frequency Tolerance C): ±0.3ppm Frequency stability: ± 0.28ppm over -40 C ~ +85 C Frequency step resolution by DAC: 10ppb/Step Support packet-based real-time processing Support 4x4 and 8x8 MIMO signal processing Fixed initial phase difference between each case Packet synchronization Crystal synchronization

29 29 Provided function Init_C: initialize platform Analog_setting_C: set RF module parameters TX gain, RX gain, crystal, frequency band, bandwidth, I/Q imbalance, hopping function TX_C: transmit matlab generated signal Repeat number RX_C: receive RF module signal to matlab variable Sample length RXDE_C: associated with TX function when repeat number is one

30 30 Usage case 1 TX only: Arbitrary waveform generator (AWG) Transmit any waveform from matlab Setting parameters: repeat number TX_exp_with_TX_gain.m

31 31 Usage case 2 RX only: Scope Log RF to Basedband waveform Setting parameters: log length

32 32 Usage case 3 Packet-based real-time transmission: Dual link transmission Transmit a packet Decode ACK packet Transmit next packet Decode ACK packet Decode a packet Transmit an ACK packet Decode another packet Transmit an ACK packet

33 33 Usage case 3 Dual link transmission

34 OFDM case 34

35 35 Usage case 4 Packet-based real-time transmission: Single link transmission Transmit a packet Waiting a certain time Transmit next packet Decode a packet Decode another packet

36 36 Usage case 5 MIMO processing study: Matlab code Ethernet M 3 FORCE-C1056A Platform M 3 FORCE-C1056A Platform

37 Conclusions We introduce our point of view for mmwave RF module Hybrid beamforing is better Two layers with polarization is better Fast beam change is required We Introduce our solution of mmwave RF module for OAI Frequency band:27.5ghz~28.3ghz 4 x 4 (or 4x2) antenna array EIRP: 4x2 case H:~29dBm, V:26.3dBm Dual polarization with same antenna 2-stream Horizontal field of view:120 degrees Vertical field of view:120 degrees Total 8 fast beam tables 37