Synchronization method and apparatus for orthogonal frequency division multiplexing system

A synchronization apparatus used in a receiving terminal of an orthogonal frequency division multiplexing (OFDM) system, the synchronization apparatus comprising:

• a receiving unit receiving an OFDM training symbol, wherein the OFDM training symbol comprises a plurality of sample points;
• and
• a timing synchronization unit coupled to the receiving unit and comprising:
• a first function-calculating unit calculating a plurality of first function values according to the sample points by using a first function, and selecting D timing points from a plurality of timing points corresponding to the first function values, wherein the D first function values of the D timing points are greater than a first threshold value, and D is a positive integer representing the number of the selected timing points;
• and
• a second function-calculating unit coupled to the first function-calculating unit, calculating D second function values of the D timing points by using a second function, selecting a first timing point from the D timing points, and setting the first timing point as a timing synchronization point, wherein the second function value of the first timing point is a first one greater than a second threshold value.

An orthogonal frequency division multiplexing (OFDM) system, comprising a receiving terminal and a transmitting terminal, wherein the transmitting terminal is configured to generate an OFDM training symbol, and the receiving terminal comprises:

• a receiving unit receiving the OFDM training symbol from the transmitting terminal, wherein the OFDM training symbol comprises a plurality of sample points;
• and
• a timing synchronization unit coupled to the receiving unit and comprising:
• a first function-calculating unit calculating a plurality of first function values according to the sample points by using a first function, and selecting D timing points from a plurality of timing points corresponding to the first function values, wherein the D first function values of the D timing points are greater than a first threshold value, and D is a positive integer representing the number of the selected timing points;
• and
• a second function-calculating unit coupled to the first function-calculating unit, calculating D second function values of the D timing points by using a second function, selecting a first timing point from the D timing points, and setting the first timing point as a timing synchronization point, wherein the second function value of the first timing point is a first one greater than a second threshold value.