A Symbol Synchronization Algorithm for PCC OFDM Systems

T. Salim, J. Devlin, and J. Whittington (Australia)

Keywords

Orthogonal Frequency Division Multiplexing (OFDM), Polynomial Cancellation Coding OFDM (PCC OFDM), Timing synchronization, Correlation function.

Abstract

—OFDM is a popular technique for multimedia transmission but it has number of disadvantages. These are sensitivity to frequency offset, relatively large out of band power and high peak to mean transmitted power. PCC (Polynomial Cancellation Coding) OFDM is a coding method for OFDM where data is mapped onto weighted groups of subcarriers rather than onto individual subcarriers. The weighting and adding property of PCC solves many of the drawbacks of OFDM. In this paper we discuss a symbol synchronization method for PCC OFDM communication system. The algorithm derives an estimate of the symbol timing offset from pilot tones. A periodic pattern of four symbols is used for this purpose. The first pair of symbol periods is transmitted with identical polarity pilots and the next two symbols are modulated with the opposite polarity pilots. A correlation matrix is derived from the known data and is employed to detect the start of symbol period. Performance of the estimator exhibits low bias and variance.

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