T. Salim, J. Devlin, and J. Whittington (Australia)
Orthogonal Frequency Division
Multiplexing (OFDM), Polynomial Cancellation Coding
OFDM (PCC OFDM), Timing synchronization,
—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