| 摘要 |
PURPOSE: To perform symbol synchronization detection by reference symbol correlation in a small-scale circuit. CONSTITUTION: This system is provided with a circuit 103 for quadrature detecting OFDM signals, the circuit 118 for detecting a null symbol from quadrature detection output, the circuit 119 for generating input synchronization timing signals based on null symbol detection output, RAMs 107 and 108 for fetching a reference symbol valid part and several data in front and behind from the quadrature detection output based on the timing signals, a ROM 109 for generating the I or Q axis data of the reference symbol valid part, correlation devices 111 and 112 for repeatedly computing correlation with data series from the ROM 109 while offsetting a RAM read start position and detecting the correlation of the reference symbol, the circuits 111-116 for obtaining and adding the absolute values of respective correlation output, successively comparing the added output and detecting a maximum value and the circuit 117 for detecting the deviation of a symbol timing from an offset amount at the time of detecting the maximum value and correcting synchronization timing generation. |
