A preamble acquisition apparatus includes a first PN code generation unit for generating a first PN code having a bit string, a first correlation calculation unit for correlating a received frequency domain preamble signal with the first PN code within a first correlation range to generate a first correlation value, a first correlation value comparison unit for comparing the first correlation value with a first threshold value, a second PN code generation unit for generating a second PN code, a second correlation calculation unit for correlating the received frequency domain preamble signal with the second PN code within a second correlation range to generate a second correlation value, and a preamble acquisition determination unit for comparing the second correlation value with a second threshold value to determine whether to acquire the preamble. The bit values of the first PN code are located in the second PN code.