Patent ID: 7561560

Claim:
A symbol timing synchronization system for OFDM systems, comprising: a shift register, for storing a first symbol and a second symbol being adjacent to the first symbol, and for receiving a symbol index; wherein, according to the symbol index and a set value, the symbol index minus the set value being a first pointer, the symbol index being a second pointer, and the symbol index plus the set value being a third pointer; according to the first pointer, the second pointer and the third pointer, a first content value, a second content value and a third content value obtained respectively; a comparing device, for comparing the first content value, the second content value and the third content value, so as to determine whether the first symbol is interfered; and a compensator to compensate the interfered first symbol if the first symbol is interfered, wherein the comparing device comprises: a first register, for storing the first content value; a second register, for storing the second content value; a third register, for storing the third content value; a first subtracter, for obtaining the difference between the second content value and the first content value, as a first difference value; a second subtracter, for obtaining the difference between the second content value and the third content value, as a second difference value; a first absolute value extractor, for obtaining a absolute value of the first difference value; a second absolute value extractor, for obtaining a absolute value of the second difference value; a comparator for comparing the absolute value of the first difference value with the absolute value of the second difference value: if the absolute value of the first difference value is greater than the absolute value of the second difference value, the first symbol is interfered, and a compensation enabling signal is output to the compensator.