Patent ID: 8045448

Claim:
A packet detecting apparatus, comprising: a cross-correlation calculator for calculating a cross-correlation value of a reception signal received from the outside and delaying the calculated cross-correlation value by a predetermined sample time; a power calculator for calculating a power value of the reception signal; and a packet detector for determining if a packet exists in the reception signal by comparing the delayed cross-correlation value with the calculated power value, and detecting the corresponding packet, wherein the reception signal includes a zero-padded symbol; the zero-padded symbol includes time-domain preamble samples and zero-padded suffix samples; the cross-correlation calculator delays the reception signal by a zero-padded sample time; the cross-correlation calculator delays the reception signal by a time-domain preamble samples time; the cross-correlation calculator delays the reception signal by a zero-padded suffix samples time; and the power calculator accumulates the power value during an interval defined below the zero-padded sample time.