Tongyu Communication Inc.

Large Scale Antenna Systems (Massive MIMO)

𝐶𝑎𝑝𝑎𝑐𝑖𝑡𝑦( Τ𝑏 𝑠) = 𝑁𝐵log2 1 +𝑆

𝑁 + 𝐼

Additional channels due to

huge number of antennas

Contiguous available bandwidth

Optimized Signal to Noise+Interference

ratio due to adaptive beam forming

Dr. Doudou Samb, Base Station Antenna R&D PL

Technical Director, 4.5G/5G Lead

High-rise building

coverage: Limited

directive antennas (in

azimuth/elevation plan)

resulting on limitation

in terms of high order

sectorization.

Capacity lift @Macro Site and Uplink Coverage& Capacity Limited: For a

given allocated time-frequency, there is still challenge during multiplexing of

different users due to small number of available antennas being able to direct

azimuth narrow beam at desired direction while nulling interferers of intra-

and inter-cell efficiently. Besides, business expansion along with difficulty in

acquiring new site where UL:DL is 1:3

High In-Building Capacity growth:

Even in claimed SU-MIMO, resources

are not exploited fully due to limited

size of user devices. Besides, Higher

cost for in-building system, with poor

WLAN performance.

Problems or Challenges: Current Antenna Systems?

Solution:3D-MIMO via

Large Scale Antenna

Systems

Efficient management covering as

much frequency bands as possible

Low tower load with

acceptable dimensions for multiple

service applications

Low latency with

significant capacity out

of a given flexible

bandwidth

System upgrade

needed, but worrying

about impact on live

networks

Coverage not big issue but capacity is!

One antenna to realize coverage in

low and tall building, high beam

forming to realize penetration

resistance

Accurate and flexible tri-angle

beam forming to support more

users MU -BF

Beam forming On the Go: 3D-MIMO

- Increased Spectrum efficiency by Smart collocated or

conformal antenna arrays along with Vertical beam

adjustment.

- Key technology driving 4.5G/5G recently.

- Standardization should be promote with effort,

prototype along with network deployment pilot.

- In the Long-term, beam forming in higher frequency and

hardware progress can be considered

Multi-beam antenna array( multi-input, simultaneous multi-beam antenna array)

1. Passive “special” feed network：Butler matrix，Rotman lens

2. Stacked-beam (electrical-large antennas (eg, reflector or dielectric lens) with multi-source stimulated,)

3. Digital phased array

Massive MIMO Techniques

Digital phased array

Digital signal

Active phased array

ANT ANT ANT

Low power signal

Passive phased array

Phase

shifter

Phase

shifter

Phase

shifter

ANT ANT ANT

Analog signal

Antenna feeding network

Potential Scheme

Principle and solution：- With 8*8 array，all together 64 antenna units，output 64

RF ports and 1 calibration port;

- Antenna array consists of 4 parts of sub-array module

including antenna units, feeding network and 16 to 1

calibration network;

- Each sub-array module consists of 16 antenna units,（4

lines 4 rows）and 1 set of 16 to 1 calibration network;

every two antenna units through one to two splitter,

combine to one RF port, and output 16 RF ports（including

eight +45°polarization ports and eight -45°polarization

ports ） and 1 calibration sub-port;

- 4 sub-array module output four 16 to 1 calibration ports,

and realize 4 to 1 function on the back of antenna，so that

to realize whole antenna function of 64 to 1 calibration

Coupling Characterization Model

Out1

OutN

.

.

.

0 0

i i

r aS

r a

00 0

0

i

i ii

S SS

S S

Let’s denote 0a the incident wave to the antenna input (corresponds also to the feeding

network input) and 0r the corresponding reflected wave. We model also ia as the thi

incident wave to the thi output of the feeding network, ir being the thi reflected wave from

the thi antenna element to the thi output of the feeding network. Thus, by denoting S as the

scattering matrix, the parameter relation for the feeding network can be derived as:

Where 00S is the reflection coefficient of the feeding network, 0 0i iS S is a 1xN sub-matrix

characterizing the power transfer vector to the feeding network outputs and iiS a NxN sub-

matrix characterizing the coupling relation of the feeding network outputs. The array

structure is designed and optimized using HFSS. In this experiment an 11-elements is

considered as can be seen from fig.2. And the corresponding array S-parameters arrS and

each element’s pattern iP can be obtained.

eTILT EBW SLL(0-30°) SLL1(First) SLL2(Max)

TEST MC-F TEST MC-F TEST MC-F TEST MC-F TEST MC-F

1700 0.85 1 7.18 7.34 21.12 17.42 21.12 17.42 21.12 17.42

1800 0.85 0 6.88 7.01 17.32 21.04 25.53 22.54 17.32 21.04

1900 0.85 1 6.39 6.63 18.79 20.83 24.65 21.86 18.79 20.83

2000 1.27 0 6.22 6.32 18.38 24.53 29.54 26.25 18.38 22.89

2100 0.85 1 6.16 5.85 21.69 15.96 29.07 20.48 19.92 15.96

2200 0.85 0 5.91 5.75 22.91 18.44 22.91 22.25 19.36 18.44

2300 1.06 0 5.43 5.49 18.61 19.78 23.9 21.22 17.8 19.78

2400 0.85 0 5.56 5.37 15.71 17.36 15.71 17.36 15.71 17.36

2500 0.43 0 5.28 5.11 19.38 18.32 19.38 18.32 17.15 17.5

2600 1.06 0 5.01 4.82 19.46 18.53 23.22 20.69 12.43 12.24

2700 0.85 0 4.58 4.61 14.26 16.58 14.26 16.58 10.58 10.36

MAX 1.27 1.00 7.18 7.34 22.91 24.53 29.54 26.25 21.12 22.89

MIN 0.43 0.00 4.58 4.61 14.26 15.96 14.26 16.58 10.58 10.36

AVG 0.89 0.27 5.87 5.85 18.88 18.98 22.66 20.45 17.14 17.62

Simulation and Measurement Results Analysis

Potential Scheme

Array layout

Vertical-plane Feeding-Networks Horizontal-plane Feeding-Networks

Po

rt

Matrix Switch

Outline

Cab

le

Vertical-palneCable Horizontal-palne

Ca

ble

Matrix Switch Outline

Platform Schematic (Scheme 2)

4 for 1

Microwave

switch

Control

line

RF

cable

RF cable

RF cable

RF cable

RF cable

RR

U

RRU

RRU

Control

Port

Loa

d

Multi beam

network

port, ie,

beam port

1dB

H-Plane 7 beamsV-Plane 8 beams

1dB

Simulation Results