media-based modulation 1 amir k. khandani [email protected] e&ce department, university of...
TRANSCRIPT
![Page 1: Media-based Modulation 1 Amir K. Khandani khandani@uwaterloo.ca E&CE Department, University of Waterloo khandani@uwaterloo.cakhandani@uwaterloo.ca, 519-8851211](https://reader035.vdocuments.net/reader035/viewer/2022062803/56649f3b5503460f94c5a0a6/html5/thumbnails/1.jpg)
Media-based Modulation
1
Amir K. [email protected]
E&CE Department, University of [email protected], 519-8851211 ext 35324
![Page 2: Media-based Modulation 1 Amir K. Khandani khandani@uwaterloo.ca E&CE Department, University of Waterloo khandani@uwaterloo.cakhandani@uwaterloo.ca, 519-8851211](https://reader035.vdocuments.net/reader035/viewer/2022062803/56649f3b5503460f94c5a0a6/html5/thumbnails/2.jpg)
2ISIT 2013
Media-based vs. (legacy) Source-based
• Main idea:– Embed the information in the variation of the RF channel external
to the antenna.
• Benefits vs. (legacy) source-based wireless:• Additive information over multiple receive antennas (similar to MIMO)
with the advantages of:– Using a single transmit antenna – Independence of noise over receive antennas
• Inherent diversity over a static channel (constellation diversity) using single or multiple antenna(s)
– Diversity improves with the number of constellation points– Unlike MIMO, diversity does not require sacrificing the rate– It essentially coverts the Raleigh fading channel into an AWGN channel
with the same average receive energy and with a minor loss in capacity.
![Page 3: Media-based Modulation 1 Amir K. Khandani khandani@uwaterloo.ca E&CE Department, University of Waterloo khandani@uwaterloo.cakhandani@uwaterloo.ca, 519-8851211](https://reader035.vdocuments.net/reader035/viewer/2022062803/56649f3b5503460f94c5a0a6/html5/thumbnails/3.jpg)
ISIT 2013
• Keep the source shining and change the media• Rich scattering environment:
– Slightest perturbation in the environment causes independent outcomes.
• Should not be confused with RF beam-forming using parasitic elements. – RF beam-forming aims at focusing energy.– Media-based relies on additive information over receive antennas to
increase rate, and on randomness of constellation to combat slow fading.
Media-based Wireless
3
Data
Carrier
Exponential growth due to rich scattering
![Page 4: Media-based Modulation 1 Amir K. Khandani khandani@uwaterloo.ca E&CE Department, University of Waterloo khandani@uwaterloo.cakhandani@uwaterloo.ca, 519-8851211](https://reader035.vdocuments.net/reader035/viewer/2022062803/56649f3b5503460f94c5a0a6/html5/thumbnails/4.jpg)
ISIT 2013
T T
DT
Media-based: Signaling Scheme
4
Basis: OrthogonalComplex Dimensions: D
T
Raleigh channel of impulse response of length D.
E
Media-basedone complexdimension
Coded Data
At these times, coded (FEC) bits are used to select one of possible channel states.
![Page 5: Media-based Modulation 1 Amir K. Khandani khandani@uwaterloo.ca E&CE Department, University of Waterloo khandani@uwaterloo.cakhandani@uwaterloo.ca, 519-8851211](https://reader035.vdocuments.net/reader035/viewer/2022062803/56649f3b5503460f94c5a0a6/html5/thumbnails/5.jpg)
ISIT 2013
Media-based: Rate
5
CarrierVectors of Dimension K,
K=2Q is the # of Receive
Antennas
m: Data
: K-D constellation (iid Gaussian elements)
![Page 6: Media-based Modulation 1 Amir K. Khandani khandani@uwaterloo.ca E&CE Department, University of Waterloo khandani@uwaterloo.cakhandani@uwaterloo.ca, 519-8851211](https://reader035.vdocuments.net/reader035/viewer/2022062803/56649f3b5503460f94c5a0a6/html5/thumbnails/6.jpg)
6ISIT 2013
Gain due to Inherent Diversity:Typicality of Random Constellation
zy
qN
m: Data
AWGN:Carrier of Energy E
2
.)(
])(2log2
1)()2log(
2
1[
)}](2log2
1{)2log(
2
1[)()(
),()1(2
|2
|222
|222
x
hxPLGhN
hNN
c
GY
hNNCYq
xdehxxfK
L
hdecfeK
eEeKhzNHyHI
q
q
Q
q
GaussianNmhy q ~)(
y
![Page 7: Media-based Modulation 1 Amir K. Khandani khandani@uwaterloo.ca E&CE Department, University of Waterloo khandani@uwaterloo.cakhandani@uwaterloo.ca, 519-8851211](https://reader035.vdocuments.net/reader035/viewer/2022062803/56649f3b5503460f94c5a0a6/html5/thumbnails/7.jpg)
K
KKAwhere
LAee
L
K
K
K
xdehxxfK
L
hdehfeK
eEeKI
K
K
q
q
Q
q
K
K
cQ
c
x
hxPLGhN
hNN
c
GY
hNNCY
2
222
2
)12/()1/2(2,
1)
)12/((
)1/2(2
)(
])(2log2
1)()2log(
2
1[
)}](2log2
1{)2log(
2
1[
/2
),()1(2
|2
|222
|222
Main Computational Tool
Las
LresultaAs
K
hNq ,01
,/2
|2
![Page 8: Media-based Modulation 1 Amir K. Khandani khandani@uwaterloo.ca E&CE Department, University of Waterloo khandani@uwaterloo.cakhandani@uwaterloo.ca, 519-8851211](https://reader035.vdocuments.net/reader035/viewer/2022062803/56649f3b5503460f94c5a0a6/html5/thumbnails/8.jpg)
8ISIT 2013
Main Conclusion of
• Consider a slow Raleigh fading channel for which statistical average of the fading gain per receive antenna is one.– Using a single TX and Q RX antennas over such
channel, mutual information averaged over different realizations of a constellation with L points approaches the capacity of 2Q parallel AWGN channels, each with unit energy, as
Las
L
K
hNq ,01
/2
|2
![Page 9: Media-based Modulation 1 Amir K. Khandani khandani@uwaterloo.ca E&CE Department, University of Waterloo khandani@uwaterloo.cakhandani@uwaterloo.ca, 519-8851211](https://reader035.vdocuments.net/reader035/viewer/2022062803/56649f3b5503460f94c5a0a6/html5/thumbnails/9.jpg)
Accuracy of the Computational Tool and its Simplified Version in Non-asymptotic Situations
L=256, Q=1 (SISO)
SNR
Mut
ual I
nfor
mat
ion Simulation of the
actual average
Simulation of the analytical bound
Simplified analytical
bound
![Page 10: Media-based Modulation 1 Amir K. Khandani khandani@uwaterloo.ca E&CE Department, University of Waterloo khandani@uwaterloo.cakhandani@uwaterloo.ca, 519-8851211](https://reader035.vdocuments.net/reader035/viewer/2022062803/56649f3b5503460f94c5a0a6/html5/thumbnails/10.jpg)
10ISIT 2013
Main Benefit: Inherent Diversity in A Single Constellation
• Conventional method suffer from deep fades in slow fading.• This problem disappear as “Good and Bad” channel realizations
contribute to forming the constellation.
![Page 11: Media-based Modulation 1 Amir K. Khandani khandani@uwaterloo.ca E&CE Department, University of Waterloo khandani@uwaterloo.cakhandani@uwaterloo.ca, 519-8851211](https://reader035.vdocuments.net/reader035/viewer/2022062803/56649f3b5503460f94c5a0a6/html5/thumbnails/11.jpg)
ISIT 2013
Media-basedone complexdimension
Media-based vs. Source-based
11
E
Data
Better Performance
Total signal energy: KE Basis: OrthogonalComplex Dimension/sec/Hz: K
Total signal energy: KE Basis: Non-orthogonalComplex Dimensions/sec/Hz: K
KxKMIMO
K complex
Dimensions
E/K
E/K
E/K
H
![Page 12: Media-based Modulation 1 Amir K. Khandani khandani@uwaterloo.ca E&CE Department, University of Waterloo khandani@uwaterloo.cakhandani@uwaterloo.ca, 519-8851211](https://reader035.vdocuments.net/reader035/viewer/2022062803/56649f3b5503460f94c5a0a6/html5/thumbnails/12.jpg)
ISIT 2013
KslopeE )(
Media-based vs. Legacy Systems: Effective Dimensionality
12
: Eigenvalues of a KxK Wishart random matrix
1xK Media-based
KxK legacy MIMO
Legacy SISORate=log(1+E)
E
Rat
e
![Page 13: Media-based Modulation 1 Amir K. Khandani khandani@uwaterloo.ca E&CE Department, University of Waterloo khandani@uwaterloo.cakhandani@uwaterloo.ca, 519-8851211](https://reader035.vdocuments.net/reader035/viewer/2022062803/56649f3b5503460f94c5a0a6/html5/thumbnails/13.jpg)
13ISIT 2013
Selection Gain• Select a subset of points, which, subject to uniform
probabilities, maximize the mutual information. • In practice, using the subset of points with highest
energy, which maximizes the slope the rate at zero SNR, performs very well.
![Page 14: Media-based Modulation 1 Amir K. Khandani khandani@uwaterloo.ca E&CE Department, University of Waterloo khandani@uwaterloo.cakhandani@uwaterloo.ca, 519-8851211](https://reader035.vdocuments.net/reader035/viewer/2022062803/56649f3b5503460f94c5a0a6/html5/thumbnails/14.jpg)
ISIT 2013
Media-based vs. Legacy Systems: Slope of Rate vs. SNR (dB) at SNR=0
• Legacy SISO: Slope=1• Legacy KxK MIMO: Maximum eigenvalue of a
KxK Wishart matrix (upper limited by 4)• 1xK Media-based: K
• Selection Gain further increases the slope of media-based to: – e.g. average slope scales as log(L) for SISO case.
14
L=1, K=2 L=1, K=4 L=1, K=8 L=1, K=infinity
KxK MIMO 1.75 2.45 2.96 4
1xK Media-based 2 4 8 Infinity
.,,1,max Lici
![Page 15: Media-based Modulation 1 Amir K. Khandani khandani@uwaterloo.ca E&CE Department, University of Waterloo khandani@uwaterloo.cakhandani@uwaterloo.ca, 519-8851211](https://reader035.vdocuments.net/reader035/viewer/2022062803/56649f3b5503460f94c5a0a6/html5/thumbnails/15.jpg)
15ISIT 2013
Comparison with Ergodic Capacity
![Page 16: Media-based Modulation 1 Amir K. Khandani khandani@uwaterloo.ca E&CE Department, University of Waterloo khandani@uwaterloo.cakhandani@uwaterloo.ca, 519-8851211](https://reader035.vdocuments.net/reader035/viewer/2022062803/56649f3b5503460f94c5a0a6/html5/thumbnails/16.jpg)
16ISIT 2013
Comparison with Outage Capacity