doc.: ieee 802.22-05/0102r1 submission november 2005 hach, lampe; nanotronslide 1 nanotron mdma ebm...
TRANSCRIPT
November 2005
Hach, Lampe; Nanotron
Slide 1
doc.: IEEE 802.22-05/0102r1
Submission
Nanotron MDMA EBM ProposalIEEE P802.22 Wireless RANs Date: 2005-11-07
Name Company Address Phone email John Lampe Nanotron
Technologies GmbH
Alt-Moabit 60, 10555 Berlin, Germany
+49 30 399 954 0
Rainer Hach Nanotron Technologies GmbH
Alt-Moabit 60, 10555 Berlin, Germany
+49 30 399 954 0
Authors:
Notice: This document has been prepared to assist IEEE 802.22. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein.
Release: The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.22.
Patent Policy and Procedures: The contributor is familiar with the IEEE 802 Patent Policy and Procedures http://standards.ieee.org/guides/bylaws/sb-bylaws.pdf including the statement "IEEE standards may include the known use of patent(s), including patent applications, provided the IEEE receives assurance from the patent holder or applicant with respect to patents essential for compliance with both mandatory and optional portions of the standard." Early disclosure to the Working Group of patent information that might be relevant to the standard is essential to reduce the possibility for delays in the development process and increase the likelihood that the draft publication will be approved for publication. Please notify the Chair Carl R. Stevenson as early as possible, in written or electronic form, if patented technology (or technology under patent application) might be incorporated into a draft standard being developed within the IEEE 802.22 Working Group. If you have questions, contact the IEEE Patent Committee Administrator at [email protected].>
November 2005
Hach, Lampe; Nanotron
Slide 2
doc.: IEEE 802.22-05/0102r1
Submission
Abstract
• A brief history of chirp pulses
• CSS properties
• MDMA
• EBM
• MCP
• Summary
November 2005
Hach, Lampe; Nanotron
Slide 3
doc.: IEEE 802.22-05/0102r1
Submission
Basic Technologies
MDMAMulti Dimensional Multiple Access New modulation technique High data rates Robust Flexible Easy to implement
MCPMulti Choice Precoding Echo cancellation method Easy to implement on subscriber side Uses the energy of reflected waves Enabler in non-LOS environments
SDS-TWR and TOASymmetric Double Sided Two Way Ranging and Time of Arrival
• New ranging method with best accuracy per MHz• Chirp-based pulse edge arrival accuracy using well-known principles re-
applied
November 2005
Hach, Lampe; Nanotron
Slide 4
doc.: IEEE 802.22-05/0102r1
Submission
Introduction
• MDMA, EBM and MCP were designed for the WRAN-type of problem:– Base station to multiple subscribers
– Dynamic allocation of spectrum
– Dynamic trade-off of range and data rate
November 2005
Hach, Lampe; Nanotron
Slide 5
doc.: IEEE 802.22-05/0102r1
Submission
A Brief History of Chirp Pulses• Used by dolphins and bats
• Patent for radar applications about 1940 by Prof. Hüttmann, further developed by Sidney Darlington (Lifetime IEEE Fellow) in 1947 (”Pulse Compression Radar“)
• Patented by Canon for data transmission in fiber optic systems in mid-90s
• Chirp Spread Spectrum for commercial wireless data transmission investigated & patented by Nanotron since 1996
November 2005
Hach, Lampe; Nanotron
Slide 6
doc.: IEEE 802.22-05/0102r1
Submission
Characteristics of Chirp Pulses
A chirp pulse is a frequency modulated pulse
Up-Chirp in the time domain(roll-off factor 0.25)
Spectrum of the chirp pulse withbandwidth B and a roll-off factor of 0.25
B
|S(f)|
f
November 2005
Hach, Lampe; Nanotron
Slide 7
doc.: IEEE 802.22-05/0102r1
Submission
The Solution – CSSHas optimal signal forms for both RF link and baseband
November 2005
Hach, Lampe; Nanotron
Slide 8
doc.: IEEE 802.22-05/0102r1
Submission
Key Properties of CSS• High robustness
Due to the high BT product and their asynchronous nature, chirppulses are very resistant against disturbances.
• Multipath resistantDue to the frequency spreading of chirp pulses, CSS is very immune against multipath fading; CSS can even take advantage of RF echoes.
• Long rangeDue to high system gain, as well as noise, interference and fading resistance, CSS has exceptional range for a given transmit power and conditions.
• Location awarenessCSS gives the ability to determine the distance (range) between two stations.
• Low PHY latency With CSS a wireless connection can be established very quickly because synchronizations on carrier frequency and data clock are not required.
• Antenna position Reception is possible with almost any antenna position due to the wide bandwidth.
November 2005
Hach, Lampe; Nanotron
Slide 9
doc.: IEEE 802.22-05/0102r1
Submission
Mobility Property of CSS
Resistance against Doppler effect:The Doppler effect causes a frequency shift of the chirp pulse, whichintroduces a negligible shift of the baseband signal on the time axis.
Example:Bandwidth B of the chirp 64 MHzData rate 1 MbpsRelative speed between transmitter and receiver2000 km/hFrequency shift due to Doppler effect 4.52 kHzEquivalent shift of the message on the time axis 56.5 ps
Note:2000 km/h is equivalent to 1243 miles/hour
November 2005
Hach, Lampe; Nanotron
Slide 10
doc.: IEEE 802.22-05/0102r1
Submission
Chirp Properties
• Complex values of a windowed baseband up-chirp and down-chirp signals each with a total duration of 1µs
• Flat magnitude• Plenty of roll-off time
(easy to implement & meet regulatory requirements)
• Significant simplification of correlator due:a) to up-chirp and down-chirp similaritiesb) symmetry in time domain
November 2005
Hach, Lampe; Nanotron
Slide 11
doc.: IEEE 802.22-05/0102r1
Submission
Chirp Properties (cont.)
• Up-converted up-chirp and down-chirp signals each with a total duration of 1µs
November 2005
Hach, Lampe; Nanotron
Slide 12
doc.: IEEE 802.22-05/0102r1
Submission
Chirp Properties (cont.)
• Figure shows the autocorrelation function (ACF) of a chirp and cross-correlation function (CCF) of an up- and down-chirp
– Note that the CCF has a constant low value (compared to DSSS sequences).
November 2005
Hach, Lampe; Nanotron
Slide 13
doc.: IEEE 802.22-05/0102r1
Submission
Support for Interference Ingress
• Example (without FEC):– Bandwidth B of the chirp = 20 MHz
– Duration time T of the chirp = 1 µs
– Center frequency of the chirp (ISM band) = 2.437 GHz
– Processing gain, BT product of the chirp = 13 dB
– Eb/N0 at detector input (BER=10E-4) = 12 dB
– In-band carrier to interferer ratio (C/I @ BER=10-4)= 12 dB – 13 dB = -1 dB
– Implementation Loss = 1 … 2 dB
November 2005
Hach, Lampe; Nanotron
Slide 14
doc.: IEEE 802.22-05/0102r1
Submission
0.01 0.1 1 1040
50
60
70
80
90
100
110
120
130Outdoor-Propagation; a = 2.1
distance between transmitter and receive
atte
nuat
ion
[dB
] for
out
door
d1( )r
101
103
120
124
r
km
Output Power @ antenna
Range @ BER=10-3
7 dBm = 5 mW 740 m
9 dBm = 7.9 mW 940 m
26 dBm = 400 mW 6400 m
30 dBm = 1 W 9800 m
Gant = 1 dB Pout = 9 dBm,d = 940 m
Pout = 7 dBm,d = 740 m
Pout = 26 dBm,d = 6.4 km
Pout = 30 dBm,d = 9.8 km
CSS Outdoor Testing Summary
Using:
•64 MHz bandwidth
•2.4 GHz ISM band
November 2005
Hach, Lampe; Nanotron
Slide 15
doc.: IEEE 802.22-05/0102r1
Submission
nanoNET is FCC & ETSI Certified• Certification of Chirp modulation
method caused no problems despite being a completely new technology
• nanoNET is compliant with the ETSI regulations for the ISM Band: R&TTE Directive 1999/5/EC and the standards EN 300 328 V 1.4.1:2003 EN 301 489-17 V1.2.1 EN 60950-1:2001
• FCC certification is granted
• Japanese certification is granted
November 2005
Hach, Lampe; Nanotron
Slide 16
doc.: IEEE 802.22-05/0102r1
Submission
WRAN scenario
• One basestation May be a little sophisticated
• Multiple subscribers Should be inexpensive– Big differences in distance Different link attenuations have to
be managed• Some very closed to the basestation
• Some far away
• Limited Transmit power Max allowed Tx power should be utilized most of the time
• Asymetric data rate (Downlink > Uplink)
November 2005
Hach, Lampe; Nanotron
Slide 17
doc.: IEEE 802.22-05/0102r1
Submission
How to handle the different link attenuations ? Trade data rate against received symbol energy
• Common approach:– Have a fixed symbol rate, adapt the code rate
– Drawback: At some point the syncronization will fail and thus the link will break
• Alternative approach:– MDMA / EBM
• Implicitly vary the symbol energy by adapting the Tx data rate such that the Rx symbole energy stays constant (indepent from distance)accordin to changing the number of overlapping chirp symbols
November 2005
Hach, Lampe; Nanotron
Slide 18
doc.: IEEE 802.22-05/0102r1
Submission
Utilize time shift –orthogonality of chirp signals
t
frequency
t
amplitude
time overlap
November 2005
Hach, Lampe; Nanotron
Slide 19
doc.: IEEE 802.22-05/0102r1
Submission
MDMA: Time and Frequency Spreading
N O I S E
B
t0 1 t02t1 t2 t3 t4 t5 t6 t7 t 8 t9 t1 0 t11 t12 t13 Time
Po
we
r
N O I S E
B
t0 1 t02t1 t2 t3 t4 t5 t6 t7 t 8 t9 t1 0 t11 t12 t13 Time
Po
we
r
N O I S E
B
t0 1 t02t1 t2 t3 t4 t5 t6 t7 t 8 t9 t1 0 t11 t12 t13 Time
Po
we
r
N O I S E
B
t0 1 t02t1 t2 t3 t4 t5 t6 t7 t 8 t9 t1 0 t11 t12 t13 Time
Po
we
r
N O I S E
B
t0 1 t02t1 t2 t3 t4 t5 t6 t7 t 8 t9 t1 0 t11 t12 t13 Time
Po
we
r
N O I S E
B
t0 1 t02t1 t2 t3 t4 t5 t6 t7 t 8 t9 t1 0 t11 t12 t13 Time
Po
we
r
N O I S E
B
t0 1 t02t1 t2 t3 t4 t5 t6 t7 t 8 t9 t1 0 t11 t12 t13 Time
Po
we
r
N O I S E
B
t0 1 t02t1 t2 t3 t4 t5 t6 t7 t 8 t9 t1 0 t11 t12 t13 Time
Po
we
r
N O I S E
B
t0 1 t02t1 t2 t3 t4 t5 t6 t7 t 8 t9 t1 0 t11 t12 t13 Time
Po
we
r
N O I S E
B
t0 1 t02t1 t2 t3 t4 t5 t6 t7 t 8 t9 t1 0 t11 t12 t13 Time
Po
we
r
N O I S E
B
t0 1 t02t1 t2 t3 t4 t5 t6 t7 t 8 t9 t1 0 t11 t12 t13 Time
Po
we
r
N O I S E
B
t0 1 t02t1 t2 t3 t4 t5 t6 t7 t 8 t9 t1 0 t11 t12 t13 Time
Po
we
r
N O I S E
B
t0 1 t02t1 t2 t3 t4 t5 t6 t7 t 8 t9 t1 0 t11 t12 t13 Time
Po
we
r
N O I S E
B
t0 1 t02t1 t2 t3 t4 t5 t6 t7 t 8 t9 t1 0 t11 t12 t13 Time
Po
we
r
N O I S E
B
t0 1 t02t1 t2 t3 t4 t5 t6 t7 t 8 t9 t1 0 t11 t12 t13 Time
Po
we
r
N O I S E
B
t0 1 t02t1 t2 t3 t4 t5 t6 t7 t 8 t9 t1 0 t11 t12 t13 Time
Po
we
r
N O I S E
B
t0 1 t02t1 t2 t3 t4 t5 t6 t7 t 8 t9 t1 0 t11 t12 t13 Time
Po
we
r
N O I S E
B
t0 1 t02t1 t2 t3 t4 t5 t6 t7 t 8 t9 t1 0 t11 t12 t13 Time
Po
we
r
E1 E1 E1 E1 E1 E1 E1 E1 E1 E1 E1 E1
N O IS E
t1t01t2t02
t3 t4 t5 t6 t7 t 8 t9 t10 t11 t12 t13 t14 t15 t16 t17 t18 t19 Time
Po
we
r
E 0E 0
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E 0 E 0
N O IS E
t1t01t2t02
t3 t4 t5 t6 t7 t 8 t9 t10 t11 t12 t13 t14 t15 t16 t17 t18 t19 Time
Po
we
r
E 0E 0
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E 0 E 0
N O IS E
t1t01t2t02
t3 t4 t5 t6 t7 t 8 t9 t10 t11 t12 t13 t14 t15 t16 t17 t18 t19 Time
Po
we
r
E 0E 0
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E 0 E 0
N O IS E
t1t01t2t02
t3 t4 t5 t6 t7 t 8 t9 t10 t11 t12 t13 t14 t15 t16 t17 t18 t19
N O IS E
t1t01t2t02
t3 t4 t5 t6 t7 t 8 t9 t10 t11 t12 t13 t14 t15 t16 t17 t18 t19 Time
Po
we
r
E 0E 0
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E 0 E 0
N O IS E
t1t01t2t02
t3 t4 t5 t6 t7 t 8 t9 t10 t11 t12 t13 t14 t15 t16 t17 t18 t19 Time
Po
we
r
E 0E 0
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E 0 E 0
N O IS E
t1t01t2t02
t3 t4 t5 t6 t7 t 8 t9 t10 t11 t12 t13 t14 t15 t16 t17 t18 t19 Time
Po
we
r
E 0E 0
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E 0 E 0
Time
N O IS E
t1t01t2t02
t3 t4 t5 t6 t7 t 8 t9 t10 t11 t12 t13 t14 t15 t16 t17 t18 t19 Time
N O IS E
t1t01t2t02
t3 t4 t5 t6 t7 t 8 t9 t10 t11 t12 t13 t14 t15 t16 t17 t18 t19 Time
N O IS E
t1t01t2t02
t3 t4 t5 t6 t7 t 8 t9 t10 t11 t12 t13 t14 t15 t16 t17 t18 t19 Time
N O IS E
t1t01t2t02
t3 t4 t5 t6 t7 t 8 t9 t10 t11 t12 t13 t14 t15 t16 t17 t18 t19 Time
N O IS E
t1t01t2t02
t3 t4 t5 t6 t7 t 8 t9 t10 t11 t12 t13 t14 t15 t16 t17 t18 t19 Time
N O IS E
t1t01t2t02
t3 t4 t5 t6 t7 t 8 t9 t10 t11 t12 t13 t14 t15 t16 t17 t18 t19 Time
N O IS E
t1t01t2t02
t3 t4 t5 t6 t7 t 8 t9 t10 t11 t12 t13 t14 t15 t16 t17 t18 t19 Time
N O IS E
t1t01t2t02
t3 t4 t5 t6 t7 t 8 t9 t10 t11 t12 t13 t14 t15 t16 t17 t18 t19 Time
Po
we
r
E 0E 0
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
N O IS E
t1t01t2t02
t3 t4 t5 t6 t7 t 8 t9 t10 t11 t12 t13 t14 t15 t16 t17 t18 t19 Time
Po
we
r
E 0E 0
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
N O IS E
t1t01t2t02
t3 t4 t5 t6 t7 t 8 t9 t10 t11 t12 t13 t14 t15 t16 t17 t18 t19 Time
Po
we
r
E 0E 0
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
N O IS E
t1t01t2t02
t3 t4 t5 t6 t7 t 8 t9 t10 t11 t12 t13 t14 t15 t16 t17 t18 t19 Time
Po
we
r
E 0E 0
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E1
E 0 E 0
Different chirps in amplitude and in frequency spreading
November 2005
Hach, Lampe; Nanotron
Slide 20
doc.: IEEE 802.22-05/0102r1
Submission
MDMA transmitter
Variable data rate pulse generator
Fix duration chirp filter Automatic power control
November 2005
Hach, Lampe; Nanotron
Slide 21
doc.: IEEE 802.22-05/0102r1
Submission
MDMA: The Potential
MDMA can beadapted to thedemands of a givensituation – evenon the fly!
November 2005
Hach, Lampe; Nanotron
Slide 22
doc.: IEEE 802.22-05/0102r1
Submission
EBM: Variation of the Bit Energy and Rate
r [m]r max2010 30 40
E = P T [ W s ] TB B T. (r)
P = constT
E (r)
=
[ W
s
]
TB E r
BR.
2
G
T (r) = E r
PB BRT
.G .
2
E (r) = const .BR
E [Ws]R S O LU TIO N N O 1 : V AR IA T IO N O F T HE B IT DU R A TIO N
November 2005
Hach, Lampe; Nanotron
Slide 23
doc.: IEEE 802.22-05/0102r1
Submission
What can we do with a sophisticated base station? Apply precoding to compensate multipath reflections
• Under the assumption that FDD is used, the base station can estimate the channel impulse response for each downlink from the uplink signal
• Several precoding schemes that utilize the knowledge of the channel at the transmitter are known. A special one for heavy reflections is MCP
November 2005
Hach, Lampe; Nanotron
Slide 24
doc.: IEEE 802.22-05/0102r1
Submission
Introduction to MCP
(Multiple Choice Pre-coding)
November 2005
Hach, Lampe; Nanotron
Slide 25
doc.: IEEE 802.22-05/0102r1
Submission
Introduction to MCP(Multiple Choice Pre-coding)
• Task
• Problem and known possible solutions
• Constellations of BPSK, QPSK
• MCP principle
• Constellations of MCP
• Comparison of MCP with DFE and VA
• Crest factor and mean symbol energy
• Summary of MCP properties
November 2005
Hach, Lampe; Nanotron
Slide 26
doc.: IEEE 802.22-05/0102r1
Submission
Task
BaseStation
SubsriberUnit 2
SubsriberUnit 3
SubsriberUnit 1
SubsriberUnit 4
Demands: Low Cost Subscriber Units without Equalizing
channel 1
channel 2
channel 3
channel 4
November 2005
Hach, Lampe; Nanotron
Slide 27
doc.: IEEE 802.22-05/0102r1
Submission
Problem of Intersymbol Interference
transmitterchannel,
h(t) H(j)receiver
channel causes Inter-symbol Interference (ISI)
t
example of pulse response of non-ideal channel
+
=t t
November 2005
Hach, Lampe; Nanotron
Slide 28
doc.: IEEE 802.22-05/0102r1
Submission
Known possible solutions
Receiver related:-Equalizer in receiver (fractional spaced, decision feedback)-Maximum Likelihood Sequence Estimation in receiver(Viterbi Algorithm)
Transmitter related:-Tomlinson Harashima Pre-coding for uncoded signals,-Trellis-Pre-coding for coded modulated signals
new solution: MCP
November 2005
Hach, Lampe; Nanotron
Slide 29
doc.: IEEE 802.22-05/0102r1
Submission
BPSK, QPSK principles
real
imag
+1,+1
real
imag
-1 +1
-1,+1
+1,-1-1,-1
November 2005
Hach, Lampe; Nanotron
Slide 30
doc.: IEEE 802.22-05/0102r1
Submission
QPSK on postringing channel I
0 1 2 3 4 5-1.5
-1
-0.5
0
0.5
1
1.5channel
time refered to symbolduration
ampl
itude
magnitudereal imag
-2 -1 0 1 2-2
-1
0
1
2transmitted constellation
real
imag
-2 0 2-3
-2
-1
0
1
2
3received constellation
real
imag
November 2005
Hach, Lampe; Nanotron
Slide 31
doc.: IEEE 802.22-05/0102r1
Submission
BPSK on post-ringing channel I
0 1 2 3 4 5-1.5
-1
-0.5
0
0.5
1
1.5channel
time refered to symbolduration
ampl
itude
magnitudereal imag
-2 -1 0 1 2-2
-1
0
1
2transmitted constellation
real
imag
-2 0 2-3
-2
-1
0
1
2
3received constellation
real
imag
November 2005
Hach, Lampe; Nanotron
Slide 32
doc.: IEEE 802.22-05/0102r1
Submission
QPSK on post-ringing channel II
0 1 2 3 4 5-1.5
-1
-0.5
0
0.5
1
1.5channel
time refered to symbolduration
ampl
itude
magnitudereal imag
-2 -1 0 1 2-2
-1
0
1
2transmitted constellation
real
imag
-2 0 2-3
-2
-1
0
1
2
3received constellation
real
imag
November 2005
Hach, Lampe; Nanotron
Slide 33
doc.: IEEE 802.22-05/0102r1
Submission
BPSK on post-ringing channel II
0 1 2 3 4 5-1.5
-1
-0.5
0
0.5
1
1.5channel
time refered to symbolduration
ampl
itude
magnitudereal imag
-2 -1 0 1 2-2
-1
0
1
2transmitted constellation
real
imag
-2 0 2-3
-2
-1
0
1
2
3received constellation
real
imag
November 2005
Hach, Lampe; Nanotron
Slide 34
doc.: IEEE 802.22-05/0102r1
Submission
The MCP Principle: definition of multiple representations
real
imag
-1
-1 +1
+1
November 2005
Hach, Lampe; Nanotron
Slide 35
doc.: IEEE 802.22-05/0102r1
Submission
MCP principles:definition of desired detection areas
real
imag
quadrantswhich represent +1
quadrantswhich represent -1
desired detection areafor quadrant III
safety margin
November 2005
Hach, Lampe; Nanotron
Slide 36
doc.: IEEE 802.22-05/0102r1
Submission
MCP principles:possible choice for transmission of -1
Pre-calculate the expected ISI andchoose a representation for the actual information symbol which minimizes the required transmission power
real
imag
desired detectionareas for -1
pre-calculated ISI
November 2005
Hach, Lampe; Nanotron
Slide 37
doc.: IEEE 802.22-05/0102r1
Submission
MCP principles:possible choice for transmission of +1
real
imag
desired detectionareas for +1
pre-calculated ISI
November 2005
Hach, Lampe; Nanotron
Slide 38
doc.: IEEE 802.22-05/0102r1
Submission
0 1 2 3 4 5-1.5
-1
-0.5
0
0.5
1
1.5channel
ampl
itude
-2 -1 0 1 2-2
-1
0
1
2information constellation
real
imag
-2 -1 0 1 2-2
-1
0
1
2transmitted constellation
real
imag
-2 0 2-3
-2
-1
0
1
2
3received constellation
real
imag
MCP on post-ringing channel
November 2005
Hach, Lampe; Nanotron
Slide 39
doc.: IEEE 802.22-05/0102r1
Submission
Comparison, block diagram
2 PAM Source
MCP channelFIR-Filter
transmitter
2 PAM Source
threshold detection
transmitter
FIR-Filter
Decision Feedback Equalizer
channel
threshold detection
receiver
receiver
receivedbits
receivedbits
2 PAM Source
transmitter
Maximum Likelihood Sequence Estimation (Viterbi Algorithm)channel
receiver
receivedbits
November 2005
Hach, Lampe; Nanotron
Slide 40
doc.: IEEE 802.22-05/0102r1
Submission
Comparison FIR-MCP, FIR-DFE, VA
0 1 2 3 4 5 6-1
-0.5
0
0.5
1channel (rot: Realteil, grün: Imaginärteil)
0 5 10 15 20 2510
-5
100
SN
BE
R
FIR-MCPBPSK-VAFIR-DFE
November 2005
Hach, Lampe; Nanotron
Slide 41
doc.: IEEE 802.22-05/0102r1
Submission
Problem of increased crest factor
Solution: instead of “symbol-wise MCP“ use “look ahead MCP“
informationsymbolsource MCP
informationsymbolsource MCP
T T
November 2005
Hach, Lampe; Nanotron
Slide 42
doc.: IEEE 802.22-05/0102r1
Submission
Symbol-wise vs. look-ahead MCPsignal magnitude
0 50 100 150 200 250 300 350 400 450 5000
1
2
3
4ab
s( )
magnitude of transmitted signal, symbol-wise MCP
0 50 100 150 200 250 300 350 400 450 5000
1
2
3
4
time
abs(
)
magnitude of transmitted signal, look-ahead MCP
November 2005
Hach, Lampe; Nanotron
Slide 43
doc.: IEEE 802.22-05/0102r1
Submission
Symbol-wise vs. look-ahead MCP,cumulative energy
0 50 100 150 200 250 300 350 400 450 5000
100
200
300
400
500
600
700
800
900
1000
time
cumulative energy
QPSK symbolwise MCPlook-ahead MCP
November 2005
Hach, Lampe; Nanotron
Slide 44
doc.: IEEE 802.22-05/0102r1
Submission
MCP Summary• MCP uses an expanded alphabet of transmission symbols. This leads to different possible representations of the information sequence that is to be transmitted.
• MCP is a nonlinear pre-coding method for uncoded signals.
• MCP can reduce the channel induced ISI without additional effort in the receiver:
•no equalizer->no soft decision -> no ADC •no DSP/computing power is needed•no detection delay appears
• Possible increase of crest factor of the transmitted signal in symbol-wise MCP can be avoided by “look-ahead“ strategy.
• MCP can reduce the average transmission power.
November 2005
Hach, Lampe; Nanotron
Slide 45
doc.: IEEE 802.22-05/0102r1
Submission
Technology Conclusions
CSS:• Adds location-awareness • Enhances robustness, range, and mobility• Implementable with today’s technologies• Globally certifiable• Supported by global research
November 2005
Hach, Lampe; Nanotron
Slide 46
doc.: IEEE 802.22-05/0102r1
Submission
Technology Conclusions
MDMA:• The future of CSS• Allows dynamic range / data rate trade-off• Channel sensing enables adaptive use of
available spectrum• MCP allows further benefit from knowledge of
the channel conditions• EBM facilitates resource efficiency
November 2005
Hach, Lampe; Nanotron
Slide 47
doc.: IEEE 802.22-05/0102r1
Submission
To Be Done…
• Merge with other proposers
• Complete system design
• Channel model simulations
November 2005
Hach, Lampe; Nanotron
Slide 48
doc.: IEEE 802.22-05/0102r1
Submission
Thank you very much!