Delayed correlation based signal detection scheme with filter bank for OFDM signal

Delayed correlation has been used as a signal detection scheme for an orthogonal frequency devision multiplexing symbol with a cyclic prefix in spectrum sensing. Because of a frequency offset, the outputs of the delayed correlation do not lay only on a real axis of a complex plane. Therefore, the absolute value of the outputs of the delayed correlation is employed. Furthermore, with the use of a filter bank, the number of the outputs of the delayed correlators increases and the averaging over the outputs decreases noise variance. This paper proposes a new delayed correlation scheme using the filter bank and taking the absolute value of the outputs of delayed correlation. The proposed scheme improves the probability of detection as the number of the branches of the delayed correlators increases. In the case of 6 branches the proposed scheme reduces the required sample energy by 1dB for the probability of detection of 0.9.