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You searched for subject:(Inteference Channel). Showing records 1 – 2 of 2 total matches.

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University of Colorado

1. Romero, Henry Paul. Fundamental Limits of Network Communication with General Message Sets: A Combinatorial Approach.

Degree: PhD, Applied Mathematics, 2014, University of Colorado

The classical theoretical framework for communication networks is based on the simplifying assumption that each message to be sent is known to a single transmitter and intended for a single receiver. Modern communication protocols reflect this framework by treating the physical layer as a network of individual links. However, this wireline view of wireless communications fails to account for the heterogeneous nature of network demands, consisting of both unicast and multicast services, and can fail to leverage the inherent broadcast advantage of the wireless medium. This thesis extends the classical framework of a private-message interface to the physical layer to one with both private and common messages. A key difficulty, in both the description and analysis of a communication model with general messages sets, is that there are combinatorially many message possibilities. With order-theoretic language and tools from combinatorial optimization and graphical models, we develop a general framework for characterizing the fundamental limits of information transfer over large many-to-one (multiple access) and one-to-many (broadcast) communication channels with general message sets. In particular, achievable regions are proposed for arbitrary such channels. For the multiple-access channel, the achievable region is optimal, and the order-theoretic perspective both unifies and extends previous results. For the broadcast channel, the region is specialized to an inner bound to the Degree of Freedom region, a setting where it is provably optimal in select cases. This thesis provides fresh insights into the long-standing random coding technique of superposition coding to arrive at these results. Governing constraints on reliable communication through superposition coding are shown to be polymatroidal over a lattice of subsets that may not be the boolean lattice of all subsets. Permissible input distributions for superposition coding are concisely characterized through directed graphical models of conditional dependencies. The two-user interference channel is also addressed, where the state-of-the art is extended from the case with two private messages to one with an additional common message. Advisors/Committee Members: Mahesh Varanasi, Juan Restrepo, Vanja Dukic, Jem N. Corcoran, Clifford T. Mullis.

Subjects/Keywords: Information Theory; DM Multiple Access Channel; MIMO Multiple Access Channel; Broadcast Channel; Inteference Channel; Computer Sciences; Electrical and Computer Engineering; Mathematics

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Romero, H. P. (2014). Fundamental Limits of Network Communication with General Message Sets: A Combinatorial Approach. (Doctoral Dissertation). University of Colorado. Retrieved from https://scholar.colorado.edu/appm_gradetds/61

Chicago Manual of Style (16th Edition):

Romero, Henry Paul. “Fundamental Limits of Network Communication with General Message Sets: A Combinatorial Approach.” 2014. Doctoral Dissertation, University of Colorado. Accessed January 28, 2021. https://scholar.colorado.edu/appm_gradetds/61.

MLA Handbook (7th Edition):

Romero, Henry Paul. “Fundamental Limits of Network Communication with General Message Sets: A Combinatorial Approach.” 2014. Web. 28 Jan 2021.

Vancouver:

Romero HP. Fundamental Limits of Network Communication with General Message Sets: A Combinatorial Approach. [Internet] [Doctoral dissertation]. University of Colorado; 2014. [cited 2021 Jan 28]. Available from: https://scholar.colorado.edu/appm_gradetds/61.

Council of Science Editors:

Romero HP. Fundamental Limits of Network Communication with General Message Sets: A Combinatorial Approach. [Doctoral Dissertation]. University of Colorado; 2014. Available from: https://scholar.colorado.edu/appm_gradetds/61


Queensland University of Technology

2. Nguyen, Linh-Trung. Estimation and separation of linear frequency- modulated signals in wireless communications using time - frequency signal processing.

Degree: 2004, Queensland University of Technology

Signal processing has been playing a key role in providing solutions to key problems encountered in communications, in general, and in wireless communications, in particular. Time-Frequency Signal Processing (TFSP) provides eective tools for analyzing nonstationary signals where the frequency content of signals varies in time as well as for analyzing linear time-varying systems. This research aimed at exploiting the advantages of TFSP, in dealing with nonstationary signals, into the fundamental issues of signal processing, namely the signal estimation and signal separation. In particular, it has investigated the problems of (i) the Instantaneous Frequency (IF) estimation of Linear Frequency-Modulated (LFM) signals corrupted in complex-valued zero-mean Multiplicative Noise (MN), and (ii) the Underdetermined Blind Source Separation (UBSS) of LFM signals, while focusing onto the fast-growing area of Wireless Communications (WCom). A common problem in the issue of signal estimation is the estimation of the frequency of Frequency-Modulated signals which are seen in many engineering and real-life applications. Accurate frequency estimation leads to accurate recovery of the true information. In some applications, the random amplitude modulation shows up when the medium is dispersive and/or when the assumption of point target is not valid; the original signal is considered to be corrupted by an MN process thus seriously aecting the recovery of the information-bearing frequency. The IF estimation of nonstationary signals corrupted by complex-valued zero-mean MN was investigated in this research. We have proposed a Second-Order Statistics approach, rather than a Higher-Order Statistics approach, for IF estimation using Time-Frequency Distributions (TFDs). The main assumption was that the autocorrelation function of the MN is real-valued but not necessarily positive (i.e. the spectrum of the MN is symmetric but does not necessary has the highest peak at zero frequency). The estimation performance was analyzed in terms of bias and variance, and compared between four dierent TFDs: Wigner-Ville Distribution, Spectrogram, Choi-Williams Distribution and Modified B Distribution. To further improve the estimation, we proposed to use the Multiple Signal Classification algorithm and showed its better performance. It was shown that the Modified B Distribution performance was the best for Signal-to-Noise Ratio less than 10dB. In the issue of signal separation, a new research direction called Blind Source Separation (BSS) has emerged over the last decade. BSS is a fundamental technique in array signal processing aiming at recovering unobserved signals or sources from observed mixtures exploiting only the assumption of mutual independence between the signals. The term "blind" indicates that neither the structure of the mixtures nor the source signals are known to the receivers. Applications of BSS are seen in, for example, radar and sonar, communications, speech processing, biomedical signal processing. In the…

Subjects/Keywords: signal processing; wireless mobile communications; time -frequency distribution; nonstatonary signal; linear frequency - modulation; multiplicative noise(random amplitude modulation); instantaneous frequency estimation; time - frequency distribution; reduced - inteference distribution; array processing; underdetermined blind source separation; instantaneous linear mixture; spatial time - frequency distribution; vector clustering; rayleigh fading; narrowband fading channel; wideband fading channel; linear time - varying channel; wide - sense stationary uncorrelated scattering; scattering function; estimation; separation; simulation

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Nguyen, L. (2004). Estimation and separation of linear frequency- modulated signals in wireless communications using time - frequency signal processing. (Thesis). Queensland University of Technology. Retrieved from https://eprints.qut.edu.au/15984/

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Nguyen, Linh-Trung. “Estimation and separation of linear frequency- modulated signals in wireless communications using time - frequency signal processing.” 2004. Thesis, Queensland University of Technology. Accessed January 28, 2021. https://eprints.qut.edu.au/15984/.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Nguyen, Linh-Trung. “Estimation and separation of linear frequency- modulated signals in wireless communications using time - frequency signal processing.” 2004. Web. 28 Jan 2021.

Vancouver:

Nguyen L. Estimation and separation of linear frequency- modulated signals in wireless communications using time - frequency signal processing. [Internet] [Thesis]. Queensland University of Technology; 2004. [cited 2021 Jan 28]. Available from: https://eprints.qut.edu.au/15984/.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Nguyen L. Estimation and separation of linear frequency- modulated signals in wireless communications using time - frequency signal processing. [Thesis]. Queensland University of Technology; 2004. Available from: https://eprints.qut.edu.au/15984/

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

.