An effective synchronization scheme for NC-OFDM systems in cognitive radio context

In this paper, a simple and effective synchronization scheme for NC-OFDM systems is proposed. To keep the autocorrelation in the scenario of subcarriers deficiency, the preamble is consists of two identical pseudo-noise (PN) sequences instead of ZC sequences. Coarse timing estimation and fractional CFO(carrier frequency offset) estimation are completed according to the correlation between the received preamble and the known PN sequence. Simulations validate the feasibility from the aspects of timing synchronization probability and CFO's mean square error (MSE).