Frequency synchronization apparatus

A frequency synchronization apparatus for detecting a synchronization signal from a plurality of baseband signals, comprising:

• at least one signal power generator, for receiving a predetermined number of symbols of the baseband signals and respectively calculating an average quality value of the received symbols;
• a signal selector, connected to the signal power generator, for producing a first detection value according to the average quality value;
• and
• a decision unit, connected to the signal selector, including a signal processor for producing a second detection value by using a predetermined mathematical function;
• wherein the signal processor calculates a third detection value as combining the first detection value and the second detection, and the relation of the detection values are described as:
• Rn=λ·Qn+(1−λ)·Pn
• wherein Pn represents the first detection value, Qn represents the second detection value, Rn represents the third detection value, and λ represents a value selected from 0, 1, or a fraction number between 0 and 1;
• whereby, the decision unit decides whether the synchronization signal is received or not in reference with the third detection value.