Apparatus and method for acquiring a preamble in an orthogonal frequency division multiple access mobile terminal

An orthogonal frequency division multiple access (OFDMA) mobile terminal apparatus, comprising:

• a frequency domain transform unit to transform a time domain preamble signal into a frequency domain preamble signal;
• a preamble acquisition unit to acquire a preamble by correlating the transformed frequency domain preamble signal with a PN code;
• and
• a cell search unit to extract base station information of a cell where the mobile terminal apparatus is located from the acquired preamble,
• wherein the preamble acquisition unit correlates the transformed frequency domain preamble signal with a first PN code within a first correlation range to generate a first correlation value, determines whether to generate a second PN code according to the first correlation value, and correlates the transformed frequency domain preamble signal with the second PN code to determine whether to acquire the preamble.

A method for acquiring a preamble in an orthogonal frequency division multiple access (OFDMA) mobile terminal, comprising:

• correlating a received preamble signal with a first PN code within a first correlation range to generate a first correlation value;
• comparing the first correlation value with a first threshold value, and determining whether to generate a second PN code according to the comparison result;
• generating a second PN code according to the determination result;
• correlating the preamble signal with the second PN code to generate a second correlation value;
• and
• comparing the second correlation value with a second threshold value, and acquiring the second PN code as the preamble according to the comparison result.