Facta Univ. Ser.: Elec. Energ., vol. 16, No. 3, December 2003, pp. 343-353

Cyclic Spectral Analysis of OFDM/QAM Modulation Using Stochastic Matrix-Based Method

Desimir Vučić

Abstract: The cyclostationarity of the OFDM/QAM signals induced by the use of cyclic prefix or pulse shaping is the key to blind synchronization, channel identification and equalization in these systems. Therefore, continuous-time and discrete-time spectral correlation characterization of the pulse shaping OFDM/QAM signals is performed by a matrix-based stochastic method based on Markov chain signal representation. Exact analytical expression for the cyclic spectrum of the continuous-time OFDM/QAM signal is derived applying the proposed method, the characteristic cyclic features according to the cyclic prefix and/or pulse shaping employing are analyzed and some graphed results are presented.

Keywords: Signal processing, cyclic spectral analysis, orthogonal frequency-division multilpexing, OFDM, pulse shaping, spectral correlation, Markov chain.

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