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11	Synchronization analysis and simulation of a standard IEEE 802.11g OFDM signal Lowham, Keith D. 03 1900 (has links) Approved for public release, distribution is unlimited / Synchronization of orthogonal frequency-division multiplexed (OFDM) signals is significantly more difficult than synchronization of a single-carrier system. The recently approved IEEE Standard 802.11g specifies a packet-based OFDM system that provides a basis for the discussion of OFDM synchronization in a packet-based environment. Algorithms that synchronize the receiver carrier demodulation frequency and phase, the data frame, the OFDM symbol timing, and the data symbol timing are discussed and analyzed in an AWGN channel. System View simulation is used to implement the frame and carrier frequency synchronization algorithms, where the performance of these algorithms is analyzed and they are shown to be useful detection algorithms for Standard 802.11g signal reception. / Lieutenant Commander, United States Navy IEEE 80211 (Standard) Multiplexing Electrical engineering Synchronization OFDM 802.11 802.11g AWGN PBCC DSSS DSSS-OFDM Synchronization Carrier synchronization Frequency synchronization Phase synchronization Symbol synchronization System view FFT IFFT Cyclic prefix Guard interval Wireless LAN
12	A comparison of frequency offset estimation methods in Orthogonal Frequency Division Multiplexing (OFDM) systems Karaoglu, Bulent 12 1900 (has links) Approved for public release; distribution in unlimited. / OFDM is a modulation technique that achieves high data rates, increased bandwidth efficiency and robustness in multipath environments. However, OFDM has some disadvantages, such as sensitivity to channel fading, large peak to average ratio and sensitivity to frequency offset. The latter causes intercarrier interference (ICI) and a reduction in the amplitude of the desired subcarrier which results in loss of orthogonality. In this thesis, the effects of frequency offset are studied in terms of loss of orthogonality. A number of techniques for frequency offset estimation are presented and tested in computer simulations. / Lieutenant Junior Grade, Turkish Navy Multiplexing Space time codes Wireless communication systems Frequency Offset Coarse Frequency Offset Estimation Fine Frequency Offset Estimation IFFT(Inverse Fast Fourier Transform) FFT Cyclic Prefix MATLAB Preamble OFDM Symbol
13	Odhad kanálu v OFDM systémech pomocí deep learning metod / Utilization of deep learning for channel estimation in OFDM systems Hubík, Daniel January 2019 (has links) This paper describes a wireless communication model based on IEEE 802.11n. Typical methods for channel equalisation and estimation are described, such as the least squares method and the minimum mean square error method. Equalization based on deep learning was used as well. Coded and uncoded bit error rate was used as a performance identifier. Experiments with topology of the neural network has been performed. Programming languages such as MATLAB and Python were used in this work.

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