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Wireless Channel Estimation With Applications to Secret Key Generation

This research investigates techniques for iterative channel estimation to maximize channel capacity and communication security.
The contributions of this dissertation are as follows:
i)
An accurate, low-complexity approach to pilot-assisted fast-fading channel estimation for single-carrier modulation with a turbo equalizer and a decoder is proposed.
The channel is estimated using a Kalman filter (KF) followed by a zero-phase filter (ZPF) as a smoother. The combination of the ZPF with the KF of the channel estimator makes it possible to reduce the estimation error to near the Wiener bound.
ii)
A new semi-blind channel estimation technique is introduced for multiple-input-multiple-output channels. Once the channel is estimated using a few pilots, a low-order KF is employed to progressively predict the channel gains for the upcoming blocks.
iii)
The capacity of radio channels is investigated when iterative channel estimation, data detection, and decoding are employed.
By taking the uncertainty in decoded data bits into account, the channel Linear Minimum Mean Square Error (LMMSE) estimator of an iterative receiver with a given pilot ratio is obtained.
The derived error value is then used to derive a bound on capacity.
It is shown that in slow fading channels, iterative processing provides only a marginal advantage over non-iterative approach to channel estimation.
Knowing the capacity gain from iterative processing versus purely pilot-based channel estimation helps a designer to compare the performance of an iterative receiver against a non-iterative one and select the best balance between performance and cost.
iv)
A Radio channel is characterized by random parameters which can be used to generate shared secret keys by the communicating parties when the channel is estimated.
This research studies upper bounds on the rate of the secret keys extractable from iteratively estimated channels.
Various realistic scenarios are considered where the transmission is half-duplex and/or the channel is sampled under the Nyquist rate.
The effect of channel sampling interval, fading rate and noise on the key rate is demonstrated.
The results of this research can be beneficial for the design and analysis of reliable and secure mobile wireless systems. / Graduate / 0544

  1. http://hdl.handle.net/1828/5702
  2. Movahedian, A.; McGuire, M., "An Iterative Receiver for Fast Fading Channels Using Two Kalman Filters," Broadband and Wireless Computing, Communication and Applications (BWCCA), 2011 International Conference on , vol., no., pp.122,127, 26-28 Oct. 2011 doi: 10.1109/BWCCA.2011.23
  3. Movahedian, A.; McGuire, M., "On the Capacity of Iteratively Estimated Channels Using LMMSE Estimators," Vehicular Technology, IEEE Transactions on , vol.PP, no.99, pp.1,1 doi: 10.1109/TVT.2014.2320928
  4. McGuire, M.; Movahedian, A.; Sima, M., "Zero phase smoothing of radio channel estimates," Signal Processing Conference (EUSIPCO), 2012 Proceedings of the 20th European , vol., no., pp.1608,1612, 27-31 Aug. 2012
  5. Movahedian, A.; McGuire, M., "Capacity of iteratively estimated channels using LMMSE estimators," Communications, Computers and Signal Processing (PACRIM), 2013 IEEE Pacific Rim Conference on , vol., no., pp.200,205, 27-29 Aug. 2013 doi: 10.1109/PACRIM.2013.6625474
  6. Movahedian, A.; McGuire, M., "Low complexity estimation of fast fading radio channels for higher order modulation," Communications (ICC), 2013 IEEE International Conference on , vol., no., pp.5537,5541, 9-13 June 2013 doi: 10.1109/ICC.2013.6655473
  7. Movahedian, A.; McGuire, M., "Estimation of Fast-Fading Channels for Turbo Receivers With High-Order Modulation," Vehicular Technology, IEEE Transactions on , vol.62, no.2, pp.667,678, Feb. 2013 doi: 10.1109/TVT.2012.2227345
  8. McGuire, M.; Movahedian, A., "Bounds on secret key rates in fading channels under practical channel estimation schemes," Communications (ICC), 2014 IEEE International Conference on , vol., no., pp.737,742, 10-14 June 2014 doi: 10.1109/ICC.2014.6883407
Identiferoai:union.ndltd.org:uvic.ca/oai:dspace.library.uvic.ca:1828/5702
Date14 October 2014
CreatorsMovahedian, Alireza
ContributorsMcGuire, Michael Liam
Source SetsUniversity of Victoria
LanguageEnglish, English
Detected LanguageEnglish
TypeThesis
RightsAvailable to the World Wide Web, http://creativecommons.org/publicdomain/zero/1.0/

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