sub- nyquist sampling of wideband signals
DESCRIPTION
Sub- Nyquist Sampling of Wideband Signals. Optimization of the choice of mixing sequences. Itai Friedman Tal Miller Supervised by: Deborah Cohen Technion – Israel Institute of Technology. Presentation Outline. System Description Project Objective Main Project Stages. - PowerPoint PPT PresentationTRANSCRIPT
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Sub-Nyquist Sampling of Wideband Signals
Itai Friedman Tal Miller
Supervised by:
Deborah Cohen
Technion – Israel Institute of Technology
Optimization of the choice of mixing sequences
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Presentation Outline
System Description Project ObjectiveMain Project Stages
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Spectrum Sparsity
Spectrum is underutilizedIn a given place, at a given time, only a small number of PUs transmit concurrently
Shared Spectrum Company (SSC) – 16-18 Nov 2005
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Model
Input signal in Multiband model:
Signal support is but it is sparse.N – max number of transmissionsB – max bandwidth of each transmission
Output:
Reconstructed signalBlind detection of each transmission
Minimal achievable rate: 2NB << fNYQ
~ ~~~
Mishali & Eldar ‘09
NYQf
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The Modulated Wideband Converter (MWC)
~ ~~~
ip t
iy n
Mishali & Eldar ‘10
1
2 sT
1
2 sT
1
2 sT
snT
snT
snT
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MWC – Recovery
Sz f
~~~~
z f
SA
y f
A
S Sz f A y f †
1
2 sT
1
2 sT
1
2 sT
1
2 sT
Now we can solve a linear set of equations for input signal:
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MWC – Recovery System
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MWC – Mixing & AliasingSystem requirement:
are periodic functions with period called “Mixing functions”
Examples for :…
ip t
1
-1
pT
Frequency domain
ip t
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Project Objective
Questions:What are the best Mixing functions ?Focusing on {+1,-1} functions, what properties should the sequences have?
Main Objective: Finding optimal Mixing function sequences for effective reconstruction
ip t
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What is our part in the system?
Analog signal generation
Mixing
Filtering
Sampling
Recovery
The code already exists, we modify the mixing functions generator
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Main Project StagesDeepening the understanding of the theory behind the systemUnderstanding the current achievements in the mixing functions fieldDefining sequences criteria for optimal system performanceSimulating the different sequences in the MWC system using MatlabDetermining what are the optimal sequences based on simulations and publicating the findings
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Gantt (5 weeks)Week 5
Week 4
Week 3
Week 2
Week 1
Achievements
Understanding the fundamentals of CS
Literature review of sequences
Going over the simulation code and being able to run a simulation
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Thank youFor listening
And thanks Debby for the basis to our presentation