Transcript Brunel University

School of Engineering and Design
Current and Future Research in Wireless
Networks and Communications
Co-Directors: Professor J. Cosmas & H. Al Raweshidy
Members: Dr M. Hadjinicolaou, Dr R. Nilavalan, Dr Q, Ni, Dr J. Loo, Dr K. Banitsas
www.brunel.ac.uk/about/acad/sed
School of Engineering and Design
Aims of Wireless Networks
and Communications Centre Centre
– Carry out international quality research to obtain international
excellence in the following research areas:
–
–
–
–
–
–
Wireless Communication Networks
Broadcast Communication Networks
Mobile Communication Networks
Radio over Fibre
Future Internet
Application of Networks
– Meet the research needs of industry and society thereby
contributing to the economic competitiveness of the United
Kingdom and the quality of life.
– Make available our research output for commercialisation by
providing Research Output Products for Commercialisation.
www.brunel.ac.uk/about/acad/sed
School of Engineering and Design
Brunel University Broadcast Provisioning System
Radio Network Performance Prediction and Measurement
Brunel University MIMO/SISO Transmitters
Improved Reception in Brunel Coverage
Area for MIMO Transmissions
LoS Performance Measurements in coverage area
Lab Measurement Campaign to ascertain Improved Reception
performance compared to single antenna transmissions
6.00%
5.00%
4.00%
ESR
Diversity Measurements
with DVB-H Receivers
1TX/1RX
2TX/1TX, Delay=0.75 us
2TX/1TX, Delay=0.5 us
2TX/1TX, Delay=1 us
2TX/1TX, Delay=1.5 us
3.00%
2.00%
1.00%
0.00%
23
25
27
29 31
C/N (dB)
33
35
37
Lab Measurement Campaign to ascertain Improved
Reception performance for MIMO with speed of mobile
Errored Seconds Ratio 5% (ESR5) for different values of
Received Signal Strength Indication (RSSI)
70
12%
11%
9%
2TX/1RX, Delay=1us
60
1TX/1RX
50
SISO
40
ESR (%)
8%
ESR
Diversity Measurements
with DVB-T Receivers
MISO (DD)
6%
5%
Drive Tests in Coverage Area
30
20
10
3%
0
2%
8th
Nov.
15th
Nov.
30th
Nov.
17th
Dec.
18th
Dec.
19th
Dec.
16th
Jan. 2008
18th
Jan. 2008
0%
0.1
Prof. Cosmas
1
10
100
Doppler Frequency (Hz)
1000
www.brunel.ac.uk/about/acad/sed
School of Engineering and Design
Radio Network Service Provisioning
Mobile TV
Alerts
Telco Portal
On-Demand Magazines
On-Demand Video
*:1
*:*
Content
Creation
Sub-system
*:1
Commerce
*:*
Management
Sub-system
*:*
Service
Creation
Sub-system
*:*
1:1
*:1
Service
Management
Sub-system
1:1
transport
signaling
Prof. Cosmas
1:*
Core
Network
Cellular
RAN
1:*
*:*
*:*
1:*
Core
Network
1:*
1:*
Network QoS
Management
Sub-system
DVB-H
RAN
1:*
1:*
1:*
1:*
RAN
Management
Sub-system
www.brunel.ac.uk/about/acad/sed
School of Engineering and Design
RF - MEMS
• Development of novel Radio Frequency Micro Electro Mechanical
Switches (RF MEMS) for the future
– Applications
• Reconfigurable Antennas
– For cognitive communication systems
– Frequency Switching
– Beam steering
• Tunable Filters
– Design
• Very low insertion loss in the “ON” condition.
• Very high isolation in the “OFF” condition.
• Good linearity over a wide frequency range.
Dr. Nilavalan
The RF MEMS DESIGN
www.brunel.ac.uk/about/acad/sed
School of Engineering and Design
Antennas and Propagation
• Development of novel Antenna structures for future applications
–
–
–
–
Multi-band Antennas
Reconfigurable Antennas
Flexible Conformal Wideband Antennas
Applications
• Cognitive communication systems
– Supports Dynamic Spectrum allocations
• RFID Systems
• Medical Applications
– Design
• Electromagnetic Simulation Software
Radiation Pattern 5.4GHz
Ansoft Corporation
U & E shape (3) 4.4% and 4.3 %
0
-30
Curve Info
dB(GainTotal)
Setup1 : Sw eep1
Phi='0deg'
30
-10.00
Novel Antenna Designs
dB(GainTotal)
Setup1 : Sw eep1
Phi='90deg'
-20.00
-60
60
-30.00
-40.00
-90
90
-120
120
-150
Dr. Nilavalan
150
www.brunel.ac.uk/about/acad/sed
School of Engineering and Design
Electromagnetic Simulation
Ex
Ez
• Development of Electromagnetic Simulation Tools
Ey
Ex
t
Hz
– Finite Difference Time Domain (FDTD) methods
Hx
• Orthogonal
• Non-orthogonal
Hz
Ey
Ey
Hx
Ex
Ey
Hy
Ez
Ez
– Applications
Ex
FDTD Unit Cell
Frequency Response
• Analysis of complex Electromagnetic problems
0
Return Loss/(dB)
– Microwave Systems
– THz Systems
– Optical Systems
Hy
-10
-20
-30
-40
6
7
8
9
10
Frequency/(GHz)
11
12
0.8
0.6
0.4
0.2
0
-0.2
-0.4
0
0.5
1
Time/(ns)
1.5
2
Time and Frequency Domain Analysis
The FDTD Software
Dr. Nilavalan
www.brunel.ac.uk/about/acad/sed
School of Engineering and Design
Wavelet Video Codec - Dirac
Akiyo
2.2
DiracAkiyo
H264Akiyo
2.1
2
Dirac’s motion
estimation strategy is
more efficient than
H.264.
1.8
1.7
1.6
1.5
1.4
1.3
1.2
0
50
100
150
Frame Number
200
250
300
Motion Estimation
HD1080P Pedestrian Area Sequence, 24 frames/sec, target = 2Mbps
• Research outcome showed that the compression
performance achieved by Dirac is very close to the
H.264 and in some instances even outperform H.264.
• Dirac can be seen as a competitive alternative to the
H.264 video coding standard.
5
Dirac
H.264
4
Error (%), Target Rate - Actual Rate
– Fast and efficient semi-hierachical motion estimation
– Quality-factor based rate control
– Robust transmission and error control
1.9
Frame Error Weight
• Dirac is a general purpose open-source wavelet video
codec. It was developed by BBC and named after
British Physicist – Paul Dirac.
• Funded by BBC for the research and developments of
optimum video compression techniques for Dirac.
• New techniques developed for Dirac include:
3
2
1
0
-1
-2
-3
-4
Dirac’s rate control
is more accurately
than H.264.
-5
1
2
3
4
5
6
7
Group of Picture, GOP Number
8
9
10
Rate Control
Dr. Loo
www.brunel.ac.uk/about/acad/sed
School of Engineering and Design
Distributed Video Coding
2n  1… n  1 n … 1
•Distributed video coding is a new paradigm
for video compression which enables lowcomplexity video encoding where the bulk
of the computation is shifted to the decoder.
– Optimisation of decoding efficiency with suitable macroblock size, side
information interpolation and refinement techniques, and decoding feedback
process.
– 3D DCT transformation techniques to exploit the temporal redundancy
reduction at the encoder.
– Design of DVC architecture for multiview video coding.
– Design of DVC architecture for robust transmission of wavelet compressed
video over Internet with bandwidth efficiency.
…
GOP2
GOP1
3D DCT
Wg,1
Multiview video
coding with 3D
Transform DVC
Qk Bit planes
Quantization
extratction
Buffer
Intra frame
JDU
encoder
Yg ,n 1 Yg ,2
Wg ,1
Turbo
decoder
Qˆ
…
3D DCT
k
C y ,k Reconstru
ction
Cˆ w,k
K g ,n K g ,1
…
Key
frames
Convention
Key
…
al encoder
camera
Turbo
encoder
Intra frame
encoder
JSG
Conventional
decoder
3D DCT -1
Output
Output
Ballroom sequence(Camera 0)
39
Our algorithm
outperform H.263
Intraframe
coding
38
37
36
35
PSNR-Y(dB)
•Funded by ESPRC ORS award
•This work has developed efficient DVC
architectures and algorithms which include
…
C w, k
..
.
WZ
camera
– Suitable for uplink mobile video communication and wireless video sensor
node.
Bit-planes
34
33
32
31
H.263+ Intraframe coding
PD-DMVC
2TD-DMVC
3TD-DMVC
3TDS-DMVC
30
29
28
0
500
1000
1500
2000
2500
Bit rate of WZ frames(kbps)
R-D performance of the proposed 3D transform
domain for multiview video coding
Dr. Loo
www.brunel.ac.uk/about/acad/sed
School of Engineering and Design
Cross-layer design & optimisation for OFDMA based
broadband wireless systems (EPSRC Industrial CASE
Project in collaboration with Motorola):
–
–
–
–
–
Design of novel cross-layer scheduling framework
No requirement of perfect Channel State Information (CSI)
Solution of joint optimal subcarrier and power allocation
Support of heterogeneous QoS requirements
Applicable to both 3G LTE and WiMAX
Average delay vs CSIT error variance under target error probability Pout=0.01.
K=4 and NF=6.(K1,K2,K3,K4)=(1,1,1,1)
4
Average delay (bits/sec/Hz)
10
Class 1 user (T1=2,  1=0.250)
Class 2 user (T2=4,  2=0.400)
Class 3 user (T3=8,  3=0.450)
Class 4 user (T4=1000,  4=0.500)
3
10
2
10
1
10
Our System Design
Dr. Ni
0
0.01
0.02
0.03
0.04
0.05
0.06
CSIT variance (2h)
0.07
0.08
0.09
0.1
Simulation Results
www.brunel.ac.uk/about/acad/sed
School of Engineering and Design
Design & optimisation for IEEE 802.11e/n/p NextGeneration Wireless LAN:
– Adaptive MAC tuning mechanisms for IEEE 802.11e
– Novel MAC/PHY layer design (aggregation, MIMO/OFDM) for IEEE 802.11n high
throughput
– Cross-layer design and location-based optimization for vehicular and mobile
networks
– Adaptive VoIP/video over IEEE 802.11e/n/p single-hop and mesh networks
Our Simulation Results on Improvement for IEEE 802.11e/b
Dr. Ni
Our Simulation Results on Improvement for IEEE 802.11n
www.brunel.ac.uk/about/acad/sed
School of Engineering and Design
An Emergency TeleOrthoPaedics m-health System for
Wireless Communication Links
300
Throughput (kbps)
250
200
150
UMTS
GPRS
100
50
0
0
500
1000
1500
2000
2500
File size (kbytes)
Comparison of SMPT and FTP protocols over GSM
and GPRS
Downloading speeds for vatying file size using FTP over GPRS
and UMTS
600
300
UMTS
GPRS
250
Throughput (kbps)
Download Time (sec)
500
400
300
200
200
150
100
UMTS
GPRS
50
100
0
06:00 08:00 10:00 12:00 14:00 16:00 18:00 20:00 22:00 00:00
0
0
500
1000
1500
2000
2500
File size (kbytes)
Local time (hr:min)
Sample of X-ray images transmitted (X-rays 11D & 17D of Table 1)
Downloading timing for files of varying size using FTP over GPRS and
UMTS
Dr. Hadjinicolaou
Repeated downloading of a 450 Kbytes video clip over a period of
20 hours using FTP over GPRS
www.brunel.ac.uk/about/acad/sed
School of Engineering and Design
Spatial Data Stream Multiplexing Scheme for High
Throughput WLANs
Convolutional
Encoder
+
Puncturer
+
Interleaver
+
QAM
Baseband
Modulator
Encoder Parser
OFDM
Symbols
+
Pilots
+
Training
Sequence
NTx=2
128
IFFT
Cyclic
Prefix
NDS=2
SDSM
OFDM
Symbols
+
Pilots
+
Training
Sequence
128
IFFT
Cyclic
Prefix
Convolutional
Encoder
+
Puncturer
+
Interleaver
+
QAM
Baseband
Modulator
OFDM
Symbols
+
Pilots
+
Training
Sequence
OFDM
Multiplextor
Binary
Sink
128
IFFT
Cyclic
Prefix
P/S
128
IFFT
Cyclic
Prefix
OFDM
Multiplextor
Transmitter MIMO-OFDM PHY layer model with SDSM.
NRx=2
Channel
Estimator/
Frequency
Equalizer
OFDM
Symbols
128
FFT
Remove
Cyclic
Prefix
OFDM
Demultiplextor
P/S
SDSD
Channel
Estimator/
Frequency
Equalizer
OFDM
Symbols
128
FFT
Remove
Cyclic
Prefix
OFDM
Demultiplextor
Combiner
QAM
Baseband
Demodulator
+
Deinterleaver
+
Unpuncturer
+
Unquantized
Viterbi
Decoder
OFDM
Multiplextor
SDSM
OFDM
Symbols
+
Pilots
+
Training
Sequence
NSS=4
QAM
Baseband
Demodulator
+
Deinterleaver
+
Unpuncturer
+
Unquantized
Viterbi
Decoder
OFDM
Multiplextor
STBC
Stream Parser
Binary
Source
NSS=4
Stream Parser
NES=2
Channel
Estimator/
Frequency
Equalizer
OFDM
Symbols
128
FFT
Remove
Cyclic
Prefix
OFDM
Demultiplextor
P/S
SDSD
Channel
Estimator/
Frequency
Equalizer
OFDM
Symbols
128
FFT
Remove
Cyclic
Prefix
OFDM
Demultiplextor
Receiver MIMO-OFDM PHY layer model with SDSD
10
0
10
540
486
432
378
324
270
216
162
108
54
0
10
BER
Throughput (Mbps)
IEEE 802.11n comparison with SDSM
10
-1
-2
-3
3 dB
14
15
16
17
18
19
20
21
22
23
24
25
26
27
10
-4
3 dB
SNR (dB)
270 Mbps 2x2 system
270 Mbps with SDSM (1x1)
540 Mbps 4x4 system
540 Mbps with SDSM (2x2)
10
10
Throughput simulation results under Rayleigh flat fading channel.
Dr. Hadjinicolaou
-5
270
270
540
540
-6
0
2
Mbps
Mbps
Mbps
Mbps
2x2 system
with SDSM
4x4 system
with SDSM
4
6
8
10
12
14
16
18
20
22
24
26
E /N (dB)
b
0
BER simulation results under Rayleigh flat fading channel
www.brunel.ac.uk/about/acad/sed
School of Engineering and Design
Mobile consultant: Combining total mobility with constant access
An integrated system that will allow a medical consultant to freely move either within, or outside the hospital, while
still maintaining constant contact with the patients via videoconferencing and high-resolution imaging
Hospital
Outdoors
Benefits:
Wireless videoconferencing
High resolution imaging
(includes DICOM)
Constant access
No cost inside hospital /
minimal cost outside hospital
Can be used as pager
Can be used as an IPphone
Uses 3G cells to maintain
connection outside the
hospital
Small cost to acquire /
operate
Lightweight to carry / easy
and safe to use
Dr. Banitsas
3G network
802.11g
Mobile consultant
(inside / outside hospital)
www.brunel.ac.uk/about/acad/sed
School of Engineering and Design
Assist 4 Living: Offering sustainable, inexpensive, easy to use and reliable health care
Brunel University / Industrial partner
Non invasive sensors
Bluetooth / zigbee
Home network to support freedom of movement
Sensors to sense falling / emergency
Group of supporters to assist the patient
Continuous monitoring can detect and
improve chronic conditions
Completely mobile (BT or Zigbee to transmit to Home
Network)
Elderly people would benefit
Can freely roam outside the house
Dr. Banitsas
www.brunel.ac.uk/about/acad/sed
School of Engineering and Design
Future Research
-
Future Wireless and Wireline Internet
-
Cooperative Radio Network resource management Systems and Protocols for broadcast/cellular systems
-
Novel intelligent design of radio resource management for multi-cell LTE/WiMAX systems;
-
Transmission of new kinds of media (e.g. 3D, scalable video) over different type of wireless and wireline networks
-
Measurement of performance of heterogeneous wireless networks
-
Cross layer optimisation for OFDM systems using game theory
-
Error resilience of new kinds of media
-
Cognitive and Green Communications
-
Development of fully re-configurable antennas
-
Development System modelling tools for THz systems
-
Optimisation of PAPR for MIMO-OFDM data streams
-
Minimise the pilot symbols and training signals in order to increase the channel bandwidth by offering higher channel
capacity and therefore higher data rates.
-
Incorporate queuing model in the NBS in order to achieve realistic results for OFDMA transmissions.
-
Introduce power management utility function in order to minimize power consumption amongst the users.
-
Focus in the provision of wireless telemedicine support system covering the needs of all hospitals in Cyprus. The system will
focus primarily in emergency services covering the accident & emergency department as well as the ambulance services.
All
www.brunel.ac.uk/about/acad/sed