challenges of 5g mmwave rf module - openairinterface€¦ · we introduce our point of view for...

Challenges of 5G mmWave RF Module

Ren-Jr Chen

[email protected]/ICL/ITRI2018/06/20

Copyright 2018 ITRI 工業技術研究院

Agenda

5G Vision and Scenarios

mmWave RF module considerations

mmWave RF module solution for OAI

Conclusion

2



3



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


Antenna and RF front-end

Microwave vs. mmwave:

Isotropic Tx

d

mmWave aperture

Microwave aperture

Sphere area: 4pd2

Rx

Effective area: l2/4p

PA

PA

DAC

Beamforming weight

Up-converterPADAC

BS

UECell edge

mmWavesingle antenna

Micro-Wave single antenna BS

UECell edge

mmWave beamforming

mmWavesingle antenna

Micro-Wave single antenna

8


Beamforming architecture selection

All digital vs. hybrid beamforming:

Beamforming weight

Up-converter

PADAC

PADAC

PADAC

PA

PA

DAC

PA

PA

DAC

All digital beamforming Hybrid beamforming

Hybrid beamforming architectures may be a good choice by trading-off power consuming, cost and complexity.

12bits x 2(I/Q) x 250MHz x 64 elements= 384Gbits/s

⋮

9


Rank Issue in beamforming

rank?

MU-MIMO in different beamSpatial Multiplexing

BFℎ11 ℎ21ℎ12 ℎ22

… ℎ𝑛1… ℎ𝑛2

⋮ ⋮ℎ1𝑚 ℎ2𝑚

⋱ ⋮… ℎ𝑚𝑛

MU-MIMO in same beam

10

PA

PA

DAC

PA

PA

ADC

PA

PA

DAC

PA

PA

ADC


Polarization in beamforming

Polarization could help the rank condition in two layer beamforming

Beamforming weight

Up-converter

Two layers with polarization may be a good choice in mmWave band when using beamforming

11

PA

PA

DAC

PA

PA

DAC

PA

PA

DAC

PA

PA

DAC


Fast beamforming capability

How fast we need?

Subfram 0

Slot 0

0.586 ms8.333 ms

9.440 ms

Subfram 1 Subfram 2 Subfram 91 frame = 10 subframes

1 subframe = 8 slots

1 slot = 14 OFDM symbols

1 radio frame = 10 ms

1.0 ms

125.391 ms

1.107 ms8.333 ms

8.919 ms

Slot 1

124.870 ms

Symbol 13CP

1

Symbol 2CP

1Symbol 1C

P1

0.586 ms8.333 ms

8.919 ms

1 slot = 14 OFDM symbols

0.586 ms8.333 ms

8.919 ms

Symbol 13CP

1

Symbol 2CP

1

Symbol 1CP

1

Symbol 0CP

0

Symbol 1CP

1

72 1024 72 1024 72 1024 72 1024

72 102472 102472 1024136 1024

15408 15344

122880 122880 122880 122880

Slot 2 Slot 3 Slot 4 Slot 5 Slot 6 Slot 7

1540815344 15344 15344 15344 15344

125.391 ms 124.870 ms

12


Phase noise issue

At carrier in higher frequency, phase noise becomes significant and could result in performance degradations

Oscillator

x N

x N

D/A RF Antenna Elements

D/A RF Antenna Elements

RF Antenna Elements

RF Antenna Elements

x N

x N

• Consider PN issue in spec. design


mmWave RF module solution for OAI

14


5G mmwave platform

15


Function block of platform

XC7K325T

Kintex-7 FPGA AD9361

TX1

RX1

RX2

TX2

USBJTAG

1GBDDR3

Clock board VCTCXO

MmwaveDCI

Power

CLK OUTCLK IN

SYNC OUTSYNC IN

1GbpsEthernet mmWave

Module

M3FORCEC-C1056A

16


Hardware spec.

RF part (M3FORCEC-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

19

4x2 Phased Array 4×4 Phased Array

H V

DCI Bus DCI BusDCI Bus

1.8 VDC 1.8 VDC 1.8 VDC

H V


Ideal Beam Pattern & Beam Tables for 4-by-4 module

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

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


R3 0 45 90 135

R2 0 45 90 135

R1 0 45 90 135

R0 0 45 90 135


R3 135 90 45 0

R2 135 90 45 0

R1 135 90 45 0

R0 135 90 45 0


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

Phi=90°Vertical Beam

Phi=0°Horizontal Beam

20


Ideal Beam Pattern & Beam Tables for 2-by-4 module

Phi=90°Vertical Beam

WB /Phase C0 C1 C2 C3

R1 112.5 0 0 112.5

R0 112.5 0 0 112.5


R1 0 135 281.25 56.25

R0 0 135 281.25 56.25


R1 0 45 90 135

R0 0 45 90 135


R1 135 90 45 0

R0 135 90 45 0


R1 56.25 281.25 135 0

R0 56.25 281.25 135 0

Phi=0°Horizontal Beam

21


3-D far-field pattern

22


Far-field patterns of LTCC antenna array

23


Input Power vs. EIRP

-55 -50 -45 -40 -35 -30 -25 -20 -15 -10 -5

0

5

10

15

20

25

30

35

40

45

50

EIR

P (

dB

m)

Input Power (dBm)

Measured EIRP

-50 -45 -40 -35 -30 -25 -20 -15 -10 -5 0

-5

0

5

10

15

20

25

30

35

40

45

EIR

P (

dB

m)

Input Power (dBm)

Measured EIRP

4×2 LTCC Phased Array Module

Horizontal Polarization Vertical Polarization

29 dBm

26.3 dBm

24


28GHz distributed LO

◼ Phase noise performance⚫ 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


More about beam control

Beamforming control (case 1)

Beamforming control (case 2)

0.586 ms8.333 ms

8.919 ms0.586 ms

8.333 ms

8.919 ms

Symbol 13CP

1

Symbol 2CP

1

Symbol 1CP

1

Symbol 1CP

1

72 1024 72 1024 72 1024 72 1024

0.140µs

Beam indextiming

Data in FPGA

Beam controlin FPGA

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 a packet

Transmit an ACK packet

Decode ACK packet

Transmit next packetDecode another packet

Transmit an ACK packetDecode ACK packet

⋮

33

Usage case 3

Dual link transmission

34

OFDM case

35

Usage case 4

Packet-based real-time transmission:

Single link transmission

Transmit a packet Decode a packetWaiting a certain time

Transmit next packetDecode another packet

⋮

36

Usage case 5

MIMO processing study:

EthernetMatlab code

M3FORCE-C1056A

Platform

M3FORCE-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

challenges of 5g mmwave rf module - openairinterface€¦ · we introduce our point of view for...

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