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PRIN 2005 WOMEN Project Research unit: Universit

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Dynamic addressing-based routing scalable protocols for MANET ... To single out scalable routing protocols able to face with the dynamic topology of MANET. ... – PowerPoint PPT presentation

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Title: PRIN 2005 WOMEN Project Research unit: Universit


1
PRIN 2005 WOMEN ProjectResearch unit
Università degli Studi di Napoli Federico II
  • 5th Meeting of
  • WOMEN Project
  • Trento, February 12, 2008
  • Fabio Sterle

2
Outline
  • IQ imbalance in RF systems
  • Blind estimation of the receiver IQ imbalance
    parameters
  • IQ imbalance in DVB-T systems
  • MIMO systems
  • Multistage DF MMSE equalizer synthesis
  • Dynamic addressing-based routing scalable
    protocols for MANET
  • Tree-based routing protocol
  1. D.Mattera, F.Sterle, ML estimation of reciever
    IQ imbalance parameters, Third International
    Waveform Diversity Design Conference, Pisa
    (Italy), 4-8 June 2007.
  2. M. Lipardi, D.Mattera, F.Sterle, MMSE
    Equalization in Presence of Transmitter and
    Receiver IQ Imbaclance, Third International
    Waveform Diversity Design Conference, Pisa
    (Italy), 4-8 June 2007.
  3. D. Mattera, L. Paura, and F. Sterle, MMSE WL
    equalizer in presence of receiver IQ imbalance,
    to be published on Trans. Signal Process., April
    2008.
  4. M. Caleffi, G. Ferraiuolo, L. Paura, Augmented
    Tree-based Routing Protocol for Scalable Ad Hoc
    Networks, IEEE Internatonal Conference on Mobile
    Adhoc and Sensor Systems (MASS '07), Pisa
    (Italy), 8-11 October, 2007.
  5. M. Caleffi, G. Ferraiuolo, L. Paura, On
    Reliability of Dynamic Addressing Routing
    Protocols in Mobile Ad Hoc Networks, Proc. of
    Wireless Rural and Emergency Communications
    Conference (WRECOM '07), Roma (Italy), October
    2007.
  6. M. Caleffi, G. Ferraiuolo, and L.Paura, A
    Reliability-based Framework for Multi-path
    Routing Analysis in Mobile Ad-Hoc Networks, to
    appear on International Journal of Communication
    Networks and Distributed Systems.

3
  • IQ imbalance in RF systems

4
Direct-frequency conversion
  • The imperfections in the analog stage are due to
    low-cost fabrication technologies.

Low-pass equivalent model
(received signal)
useful signal
noise
5
Direct-frequency conversion
  • The imperfections in the analog stage are due to
    low-cost fabrication technologies.

6
IQ imbalance in multicarrier system
  • The OFDM system

The input signal of the DDC stage is
7
IQ imbalance in multicarrier system
  • The OFDM system

8
IQ imbalance in multicarrier system
  • The OFDM system

9
IQ imbalance in multicarrier system
  • The OFDM system

IQ distorsion or interference
10
IQ imbalance compensation
  • The IQ imbalance at the receiver can be
    compensated provided that the IQ imbalance level
    is known
  • In fact, it is easy verified that

11
ML Estimation of the IQ parameters
  • The IQ imbalance parameters are blindly estimated
    according to the maximum-likelihood (ML)
    criterion.
  • Assumptions
  • 1) The transmitted signal is circularly
    symmetric.
  • 2) The noise is zero-mean white Gaussian
    circularly symmetric.

12
MLE for Gaussian signal
  • The transmitted signal is modeled as a Gaussian
    process.

Likelihood function for unknown a and ? (N
received samples)
1) low computational complexity 2) robustness
13
Numerical results estimation
  • Parameter setting
  • K is the number of received samples
  • SNR? 1/sn225dB
  • 64-QAM
  • AWGN and Frequency
  • Selective Channel (FCS)

14
Numerical results SER vs. K
  • Parameter setting
  • IQ mismatch a0.1 (10), ?p/18 (10)
  • K is the number of received samples
  • 64-QAM
  • SNR? 1/sn225dB
  • Existing method

15
Numerical results IIR vs. K
  • Parameter setting
  • K is the number of received samples
  • SNR? 1/sn225dB
  • 64-QAM
  • Image Rejection Ratio (IIR)

16
DVB-T system
  • Matlab Simulink to create a DVB-T environment.

17
IQ imbalance in DVB-T systems
18
IQ imbalance in DVB-T systems
19
IQ level estimation in DVB-T system
20
BER after decoding
21
  • MIMO Systems

22
MIMO system model
  • Input-output equation of the LTI MIMO system

non-dispersive channel
23
The linear DF MMSE equalizer
  • The MIMO DF equalizer output

Feedforward-based equalizer
Successive-cancellations
24
The linear DF MMSE equalizer
  • The MIMO DF equalizer output

Feedforward-based equalizer
Multistage equalizer
25
Fast synthesis of DF equalizers
  • The DF equalizer optimization reduces to a
    least-square problem under the assumption of
    uncorrelated input and noise

Feedforward-based equalizer
Successive-cancellations
Multistage equalizer
26
Widely linear processing (WL)
F
27
Widely linear processing (WL)
  • Question When does the WL processing allow one
    to achieve a performance gain over the
    conventional linear processing?

28
The WL DF MMSE equalizer
  • The WL DF equalizer employs both a WL feedforward
    filter and a WL feedback filter to exploit the
    non-circular properties of the signals to be
    processed.

By assuming that nr (0nrNi) components of x are
real-valued, the MIMO channel input-output
equation can be rewritten as follows
The WL DF equalization is defined as the DF
equalization operating on the new channel model.
29
Multistage equalizers
  • The following multistage equalizer structures
    have been considered

feedforward-based equalizer (FFB)
multistage equalizer (MS) MS-PARALLEL
successive-cancellations equalizer (SC)
multistage equalizer (MS) MS-SC
successive-cancellations BLAST equalizer (BLAST)
multistage equalizer (MS) MS-BLAST
30
Numerical results SER vs. iter.
31
  • Dynamic addressing-based routing scalable
    protocols for MANET

32
Presentation of the activity
  • Scope
  • To single out scalable routing protocols able to
    face with the dynamic topology of MANET.
  • Approach
  • Dynamic Addressing.
  • Goal
  • To sepatate the unique terminal identifier, with
    no location information in a mobile network, from
    the routing address, which embeds a topological
    information.

33
Implementation
  • Address Allocation distributed mechanism able to
    assign to nodes an address which reflects the
    node relative position, without resorting to
    flooding.
  • Routing proactive hierarchical multi-path
    protocol, able to explore multiple paths towards
    a destination with a limited overhead.
  • Address lookup distribuited hash-based service
    (DHT) for providing the mapping between node
    identifier and routing address.

34
Results
  • Normalized packet delivery ratio versus the
    number of nodes.

35
Conclusions
  • IQ imbalance in RF systems
  • The blind estimation of the receiver IQ
    parameters has been addressed.
  • The effects of IQ imapairments in DVB-T systems
    has been presented.
  • MIMO systems
  • The DF equalizer design has been re-examined in
    terms of the conventional least-square problem.
  • The WL processing has been combined with the DF
    strategy to exploit the properties of
    rotationally variant signals.
  • Three multistage DF equalizer structures have
    been compared.
  • Routing protocols for MANET
  • An augmented tree-based routing protocol has been
    proposed to handle scalable ad-hoc networks.

36
  • Thank you
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