Challenges of 5G mmwave RF Module Ren-Jr Chen rjchen@itri.org.tw M300/ICL/ITRI 2018/06/20
Agenda 5G Vision and Scenarios mmwave RF module considerations mmwave RF module solution for OAI Conclusion 2
5G Vision and Scenarios 3
5G Vision and Scenarios Source: Qualcomm, Challenges and Design Aspects for 5G Wireless Networks 4
mm-wave: a sure solution for 5G 5
Candidate higher bands in WRC-15 & FCC Source: Huawei, D.Soldani 6
mmwave RF Module Considerations 7
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
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
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
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
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 122880 122880 122880 122880 Subfram 1 Subfram 2 Subfram 9 1.0 ms 1 subframe = 8 slots 15408 15344 15344 15344 15408 15344 15344 15344 Slot 0 Slot 1 Slot 2 Slot 3 Slot 4 Slot 5 Slot 6 Slot 7 125.391 ms 124.870 ms 125.391 ms 124.870 ms 136 1024 1 slot = 14 Symbol 0 OFDM symbols 8.333 ms 1.107 ms 9.440 ms 72 1024 Symbol 1 72 1024 Symbol 2 8.333 ms 0.586 ms 8.919 ms 72 1024 Symbol 13 72 1024 72 1024 72 1024 72 1024 1 slot = 14 OFDM Symbol 1 Symbol 1 Symbol 2 Symbol 13 symbols 8.333 ms 8.333 ms 0.586 ms 0.586 ms 8.919 ms 8.919 ms 12
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
mmwave RF module solution for OAI 14
5G mmwave platform 15
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
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
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
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
WB /Phase C0 C1 C2 C3 R3 112.5 0 0 112.5 R2 112.5 0 0 112.5 R1 112.5 0 0 112.5 R0 112.5 0 0 112.5 Ideal Beam Pattern & Beam Tables for 4-by-4 module Phi=0 Horizontal Beam NB0 /Phase C0 C1 C2 C3 R3 0 135 281.25 56.25 R2 0 135 281.25 56.25 R1 0 135 281.25 56.25 R0 0 135 281.25 56.25 NB1 /Phase C0 C1 C2 C3 R3 0 45 90 135 R2 0 45 90 135 R1 0 45 90 135 R0 0 45 90 135 NB2 /Phase C0 C1 C2 C3 R3 135 90 45 0 R2 135 90 45 0 R1 135 90 45 0 R0 135 90 45 0 Phi=90 Vertical Beam NB3 /Phase C0 C1 C2 C3 R3 56.25 281.25 135 0 R2 56.25 281.25 135 0 R1 56.25 281.25 135 0 R0 56.25 281.25 135 0 Spherical Coordinate 20
WB /Phase C0 C1 C2 C3 R1 112.5 0 0 112.5 R0 112.5 0 0 112.5 Ideal Beam Pattern & Beam Tables for 2-by-4 module Phi=0 Horizontal Beam NB0 /Phase C0 C1 C2 C3 R1 0 135 281.25 56.25 R0 0 135 281.25 56.25 NB1 /Phase C0 C1 C2 C3 R1 0 45 90 135 R0 0 45 90 135 NB2 /Phase C0 C1 C2 C3 R1 135 90 45 0 R0 135 90 45 0 Phi=90 Vertical Beam NB3 /Phase C0 C1 C2 C3 R1 56.25 281.25 135 0 R0 56.25 281.25 135 0 21
3-D far-field pattern 22
Far-field patterns of LTCC antenna array 23
Input Power vs. EIRP 4 2 LTCC Phased Array Module 45 Horizontal Polarization 50 Vertical Polarization EIRP (dbm) 40 35 30 25 20 15 10 Measured EIRP 29 dbm EIRP (dbm) 45 40 35 30 25 20 15 Measured EIRP 26.3 dbm 5 10 0 5-5 -50-45 -40-35 -30-25 -20-15 -10-5 0 Input Power (dbm) 0-55 -50-45 -40-35 -30-25 -20-15 -10-5 Input Power (dbm) 24
Phase noise performance 28GHz distributed LO INT PHN(10k~100MHz @12.25GHz)=-42.5dBc+3dB(DSB)=-39.5dBc INT PHN(10k~100MHz @24.5GHz)=-39.5dBc+6B(x2 frequency)=-33.5dbc 25
Beamforming capability Mmwave communication Very fast beam control: stable time ~140 ns Measure mmwave channel Develop beam calibration algorithm 26
CP1 CP1 CP1 CP1 Beamforming control (case 1) More about beam control Data in FPGA 72 1024 72 1024 72 1024 72 1024 Symbol 1 Symbol 1 Symbol 2 Symbol 13 Beam control in FPGA 8.333 ms 0.586 ms 8.919 ms 8.333 ms 0.586 ms 8.919 ms 0.140µs Beam index timing Beamforming control (case 2) 27
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 (@+25 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 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 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 Usage case 2 RX only: Scope Log RF to Basedband waveform Setting parameters: log length
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 Usage case 3 Dual link transmission
OFDM case 34
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 Usage case 5 MIMO processing study: Matlab code Ethernet M 3 FORCE-C1056A Platform M 3 FORCE-C1056A Platform
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