LTE a and Beyond Huawei

HUAWEI TECHNOLOGIES Co., Ltd. Huawei Confidential

LTE-A and Beyond Dr. Peiying ZhuHuawei

Nov 3 , 2010

HUAWEI TECHNOLOGIES Co., Ltd. Huawei Confidential Page 2

Mobile Broadband LandscapeCellular Wireless Law of Speed vs. Decade

30 Years

1G1G

2G2G

3G3G

4G4G

5G5G

Mbps

kbps

bps

Mbps

kbps

bps

Gbps

20202010200019901980

AMPS

?

AMPS

? Cell size shrinks Cell count increases

1

4

16

50

Mobile device for everything

Time

10G

100G

1T


The Mega Trends for Internet

Information Time

Leve

l of I

nter

actio

n Interaction

Content User

Individual Metcalfe Law (n2)

User Generated Content

Connected Group Reed Law (2n)

Smart Content

??

0 50 Years

107 Computers108 Vehicular telemetric

109 Residential & commercial buildings 1010 Industrial automation

1011 Shipping logistics1012 Consumer products


10 100 1000 10000 100000

2009

2010

2013

2016

2020

Total Traffic/ Month (Peta Bytes)Number of Mobile Broadband Users (Million)

Digital Tsunami is Driving 2020 Transformation4 Billion Mobile Broadband is the Dominating Broadband

2020 mobile traffic will close to 1,000 times than 2009

(ZetaBytes era)

Wireline Broadband Subscribers

Mobile data is only around 0.5% of the volume of wireline Internet


Technology Challenges of Cellular WirelessSpectral Efficiency need another 15 years to reach theoretical limit

0.1

0.3

0.5

1.2

2.3

10

0 1 2 3 4 5 6 7 8 9 10 11 12

GSM

EDGE

HSPA

LTE

LTE-A

Theoretical Limit

Spectral Efficiency (bits/Hz/s/sector)

20 years real-world progress

2020

Near Shannon limit


LTE-Advanced will Drive the Wireless Evolution Beyond Macro Cellular Networks

High-Order (8x8) MIMO Support

RF/IF

RF/IF

RF/IF

RF/IF

RF/IF

RF/IF

RF/IF

RF/IF

Base Band

Enhanced MIMO

Improved MU-MIMO UL SM-MIMO

CA

Carrier Aggregation

3x original bandwidth

..

..

..

Spectrum Aggregation

2x original bandwidth

Hetnet

CoMP

PicoFemto

Pico

In-Band Relay


COMP – Coordinated Multi Point Transmission

Coordinated beam switching (CBS)

Coordinated beamforming (CBF) Joint processing (JP)

Soft FFR


Virtual Antenna Set

CoMP with MU-MIMO

Combining COMP with MU-MIMO to exploit gain due to Increased virtual antenna numbers

Reduced inter-cell interferences

Serve multiple spatially separated UE simultaneously in the frequency resources (UL or DL) Exploit MIMO gain with limited antennas at terminal Total number of layers could be number of Tx antennas

instead of min( Tx, Rx) in SU-MIMO for DL (if Tx>Rx)

Trade performance with the processing complexity

Performance is still limited by inter-cell interferences


CoMP Performance

Combining CoMP with MU-MIMO improves both capacity and cell edge throughputThere is a hugh gap from theoretical predication


Research Topics: MU-MIMO enhancement

Sum capacity performance of MU-MIMO with the number of users = number of antenna = 4 for the Grassmanian, random and 3GPP LTE base codebooks.

0

5

10

15

20

25

0 5 10 15 20

SNR

Cap

acity

b/s

/Hz

zero forcing3GPP6 bit Grassmannian8 bit random12 bit random

New technology needed to short the Gap

Improvement with increasing size


Heterogeneous Network Macro Cell is deployed for coverageLow Power Nodes (LPN) are deployed to increase the throughput:

Micro: <10WattsPico: 1-2WattsRelay: 200mW [5Watts], no wired backhaulFemto: < 200mWRemote radio head (RRH) cells

The key enabling technology to form the advanced heterogeneous networks are:Enhanced Interference Coordination and Interference Cancellation

Micro\Pico\relay act as small Macro

RNPico

Femto


macro macroSignal

strength SIRHow to off-load UE into

Het-Net in this region?

100Mbps100MbpsOffload Het-Net

Traffic off-load in Hetnet• What is the better way to do offload between Macro/Micro/Pico/Relay?

- One example for how cell selection scheme impact the off-load.

30Mbps30Mbps30Mbps30Mbps30Mbps30Mbps30Mbps30Mbps30Mbps30Mbps30Mbps30Mbps


Transmission Power Unbalance in Hetnet

• Power imbalance between Macro cell and LPNs- Asymmetric coverage of DL and UL

• UE’s selecting low power node will make UL performs better, but DL interference from the macro cell will be severe

• UE’s selecting macro cell will make DL performs better, but UL is worse- With the existing cell selection algorithm, most of UEs will select Macro cell

• However in order to improve the spectrum efficiency of HetNet, it is desirable that more UEs can be served by LPNs


Interference in Hetnet

• The interference characteristics in a heterogeneous deployment can be significantly different from that in a homogeneous deployment.

• To identify a good interference management solution for HetNet is more challenging.

– Interference between Macro and Micro/Pico/relay become dominated

– More “cell edge” UEs

– UEs served by the node with low transmit power may suffer much more severe

interference

– Control channel coverage

– A user deployed HeNB can be a CSG point

(a) macro UE is interfered by the HeNB (DL)(b) macro UE causes severe interference to the

HeNB (UL)(c) HeNB interfere by another HeNB

(a)(b)

(c)


Hetnet Performance

378.84%

108.11%

511.75%

164.00%

648.39%

237.64%

746.03%

307.76%

822.75%

357.89%

918.56%

422.13%

974.46%

458.95%

1034.12%

504.78%

1120.49%

573.70%

0.00%

200.00%

400.00%

600.00%

800.00%

1000.00%

1200.00%

4 Pico 6 Pico 8 Pico 10 Pico 12 Pico 14 Pico 16 Pico 18 Pico 20 Pico

Gain of cell group averagethroughputGain of cell edge throughput

• Both cell edge and throughout increases almost linearly with the number of Pico with the additional site and backhaul cost

• Advanced interference management technology will reduce the site count to lower the cost


Research Topics: Cooperative Wireless Networks

Macro 1

Relay

Macro 2

Pico

BS

UE2

UE3

UE1

Better MIMO/CoMP performance due to reduced path loss

New network architecture to support M2M


HSPA/EVDO to LTE

Spectral Efficiency Enhancement LTE-A

More Spectrum

3-time Smaller Radius Cells

Heterogeneous Pico/Relay Cells10x

3.0x Spectrum below 3GHz, Muticarrier Aggregation

CoMP/MU-MIMO/ICIC3.3x

10x 4xBW, 2.5X spectral efficiency

eNodeB

RN 2

UE 1

UE 2

UE 7

UE 6

UE 4

UE 3

RN 1

UE 5eNodeBeNodeB

RN 2RN 2

UE 1

UE 2

UE 7

UE 6

UE 4

UE 3

RN 1RN 1

UE 5

10x3.3x3.0x10=1000 !10x3.3x3.0x10=1000 !

Many challenges await to achieve numbers like these but Huawei is already addressing them

Enablers for Mobile Broadband 3+ yearsBreaking Through Next Generation Wireless Technology Barrier will require a combination of


Thank You

Documents

LTE a and Beyond Huawei