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(some) Device Localization,
Mobility Management and
5G RAN Perspectives
Mikko Valkama
Tampere University of TechnologyFinland
+358408490756
December 16th, 2016
TAKE-5 and TUT, shortly
• Our work will primarily focus on WP3 and WP4
• WP3
– energy efficiency, mobility and localization related topics
– primarily with 5G RAN focus
• WP4
– massive MTC, ultra-reliable MTC,
– multi-radio connectivity
– front-haul, back-haul, self-backhauling technologies
– all with 5G RAN focus
• TUT based PIs: Mikko Valkama, Sergey Andreev, Yevgeni
Koucheryavy
• Contact: [email protected]
2
WP3: 5G Radio Networks and Localization
• 5G networks, substantially enhanced positioning accuracy (3GPP TR 38.913 & TR 22.862, 5GPP vision and white papers, NGMN 5G white paper, 5G Forum white papers, etc.)
E.g., 1 meter accuracy outdoors
substantially better compared to current networks (e.g. LTE OTDOA, UTDOA)
• Lots of new verticals calling for this, e.g.
self driving cars, robots, drones, intelligent traffic systems, traffic management, …
• Technical enablers
dense networks, antenna arrays, wide bandwidth, multicarrier waveforms, short radio frames/sub-frames, frequent UL pilots
www.tut.fi/5G/positioning/
WP3: 5G Radio Networks and Localization
• Developed novel cascaded Extended Kalman Filter based solutions for
High-efficiency ToA and DoA estimation and tracking in individual access nodes, based on UL reference signals
Corresponding position estimation and tracking, as well as UE clock offset estimation and tracking in a central node
Facilitates also mutual synchronization of the access nodes with mutual clock offsets
www.tut.fi/5G/positioning/
Example 1: localizing and
tracking a moving car
5
• UN in LoS with two closest ANs
• Random route, v = 20…50 km/h
• Assume ANs are mutually
unsynchronized, UNs have clock
offsets
• ANs have 2D concentric circular
antenna arrays consisting of 9
cross-dipoles
• Uplink reference signal TX power =
+3 dBm
• OFDM waveform, B = 100MHz, fc =
3.5GHz
• Detailed ray-tracing based
propagation modeling
See demo at: www.tut.fi/5G/TWC16
50 m
Fig. Madrid grid
Access nodes:
density ~ 50m*
Streets
Housing block
Example 1: localizing and
tracking a moving car
6
See video at: www.tut.fi/5G/TWC16
UL reference signals processed and EKFs updated only once per 100ms
Example 2: localizing and
tracking a flying drone
7
See demo at: www.tut.fi/5G/GLOBECOM16
• A flying drone in LoS with two closest ANs
• Random flying route with max velocity of 50 km/h, including also landings
and take-offs
• Antenna models, radio frame, etc. similar to the previous example
• Detailed ray-tracing based propagation modeling
Example 2: localizing and
tracking a flying drone
8
See video at: www.tut.fi/5G/GLOBECOM16
UL reference signals processed and EKFs updated once per 100ms
WP4: wireless self-backhauling
• We have been studying three different options
for performing the self-backhauling while serving
the UEs in the uplink (UL) and downlink (DL)
– Half-duplex scheme (classical, for refence)
– Full-duplex scheme
– Relay-type scheme
• Next, these different schemes are shortly
described
12.4.2017 9
Half-duplex backhauling
• The basic scheme, where transmission and
reception are divided in time
– No interference between UEs, and essentially no
interference at all assuming good beamforming
12.4.2017 10
Time slot 1 Time slot 2
Access nodeBackhaul node
UE
UE
UE
UE
UEUE
Access nodeBackhaul node
UE
UE
UE
UE
UEUE
Inband full-duplex backhauling
• In the full-duplex scheme, all transmission and
receptions are done simultaneously
– High efficiency, but also complex interference
mechanisms
12.4.2017 11
Access nodeBackhaul node
UE
UE
UE
UE
UEUE
Relay-type backhauling
• A relay-type scheme combines the good sides of
half-duplex and full-duplex schemes
– less interference sources, while the full-duplex
capability is still leveraged in the access node
12.4.2017 12
Time slot 1 Time slot 2
Access nodeBackhaul node
UE
UE
UE
UE
UEUE
Access nodeBackhaul node
UE
UE
UE
UE
UEUE
Resource allocation:
Optimizing the transmit powers
• Careful allocation of the different transmit powers is
crucial to control the interference, and to improve the
energy-efficiency
• This can be done in different ways, such as by
mazimizing the sum-rate or ensuring a minimum
Quality-of-Service (QoS)
• Here, the results are provided for a case where the
transmit powers are minimized subject to a QoS
requirement in the form of minimum per UE spectral
efficiency
– Minimum data rate requirements for UL and DL13
Example
results
12.4.2017 14
• The optimized
TX powers
are calculated
for large amounts of randomly dropped UEs in
the network
– The cumulative distribution functions of the transmit
powers can be compared between the different
schemes
• This shows which of the schemes is capable of
fulfilling the same QoS requirements with the
best energy-efficiency (lowest transmit powers)
Parameter Value
Number of access node TX/RX antennas 200/100
Number of DL/UL UEs 10/10
Number of DL/UL backhaul streams 12/6
DL/UL rate requirement, per UE 8/2 bps/Hz
Cell radius 50 m
Distance to the backhaul node 75 m
Center-frequency 3.5 GHz
Example result 1
12.4.2017 15
• The full-duplex (FD) scheme achieves significantly lower
transmit powers both in the AN and in the UEs than the relay-
type (RL) or half-duplex (HD) schemes
– However, for some of the UE positions, it cannot fulfill the QoS
requirements with any finite transmit power (since the CDF
saturates to a value less than 1)
Example result 2
12.4.2017 16
• When investigating the total TX power usage (UL+DL), the FD
scheme also outperforms the other solutions
– However, with less SI cancellation, the probability of not fulfilling the
QoS requirements with any finite transmit power is larger
• Also, the relay scheme starts to perform rather poorly when the
amount of SI cancellation is 110 dB or less
Inhouse prototype device for
inband full-duplex
12.4.2017 17
• Fully operational full-duplex
demonstrator developed
and up and running at TUT
• Operates at 2.4 GHz ISM
band, supports up to
200 MHz instantaneous BW
• Contains advanced RF self-
interference cancellation as
well as novel digital self-
interference cancellation
solutions, all in real time
Orig
ina
l tran
sm
it da
ta (x
(n))
h1
Σ−
Σh2
hP
LM
S filte
r
we
igh
t up
da
te
Pre-computed
Σ
NI PXIe-7972R with
Kintex-7 FPGA
Ca
nce
lled
sig
na
l
NI 5791 RF transceiver LPF ↓L
TX RX
RF canceller
PA
Orth
og
on
aliz
atio
n
|x(n)|2x(n)
|x(n)|P-1
x(n)
x(n)
www.tut.fi/full-duplex
Example RF measurement results
12.4.2017 18
• Live measurements incorporating also Aalto-based back-to-back relay
antenna*, 80 MHz instantaneous BW at 2.4 GHz
• More than 100 dBs of measured TX-RX isolation
* D. Korpi, M. Heino, C. Icheln, K. Haneda, and M. Valkama, "Compact inband full-duplex relays with beyond
100 dB self-interference suppression: Enabling techniques and field measurements," IEEE Transactions on
Antennas and Propagation, accepted, to appear, 2016.
19
WP4: Massive and Ultra-reliable MTC
Objectives
• New MAC, RRM and protocol solutions to enable novel 5G use cases related to both massive and critical MTC.
• Support of ultra-reliable MTC applications and services.
Challenges
• Understanding channel behaviour (propagation) to support critical and massive connectivity communications in 5G-grade MTC scenarios.
• Propose models and solutions able to enable ultra-reliable low latency communications.
12.4.2017
20
5G-grade IoT research on factory automation
Office areaMachinery area
Transmitter 1 Transmitter 2
150 m
75 m
• Since statistical channel models are not suitable for factory environments, a comparison between “real” and statistical path loss measurements has been investigated by using our in-built Ray-based (RL) and system-level (SLS) tools.
• The conclusion is the impossibility to generalize a path loss formula for ”any” indoor scenario. Thus, a proper one has to be achieved in accordance to the environment considered.
12.4.2017
21
SNR DL Heatmaps
System-level
simulator (SLS)
Ray-based
simulator
12.4.2017
22
Pathloss assessment • Statistical channel models are only
suitable for scenarios in which theywere made.
• The gap between deterministic and“real” models is very important.
• TUT Ray-based tool is useful tocharacterize practical channelpropagation.
• A deterministic path loss formulacan be obtained through extensivesimulations.
In order to conduct a comprehensive system-level analysis, propagationbehaviour needs to be understood correctly. In doing this, our RL tool providespowerful instruments to have a complete understanding on wireless channelpropagation in factories of the future (i.e., Industry 4.0).
16.12.16
WP4: Multi-RAT Integration Reliability in Multi-RAT networks research track
Objectives:
Study options for Multi-RAT integration on different
layers.
Improve reliability in Multi-RAT networks by using
simultaneous connections to various RATs.
Challenges:
Finding application independent solutions
Balancing energy efficiency with reliability/performance
gains
16.12.16
TUT testbed setup
TUT testbed with Ericsson pico base stations, which are
connected to the Aalto EPC:
UE has both LTE and WiFi interfaces on at the same time,
and can send the same data duplicated over both links.
Duplication currently works only on application layer.
16.12.16
Example scenario concept
Application used is simple echo server.
User is moving out of WiFi coverage, so UE starts
sending data over LTE as well.
16.12.16
Future work
Consider additional scenarios:
Mission critical: Constantly send over all interfaces for maximum
reliability.
IoT: Balance energy efficiency with reliability gains.
Test with “real” applications
Prototype demo