Abstract: Two A/D converters sample received base band signal Sb by asynchronous sampling clock at double speed of symbol rate, and based on the sampled data series Ii, Qi. A transmission complex symbol frequency generator generates data series Ei, Di of transmission complex symbol frequency component. A correlation value calculator outputs correlation data series SMi as the correlation value of cosine wave data series Ci, and data series Ei, D1 of symbol frequency generated by a cosine wave generator, based on the asynchronous sampling clock CK. An inverse tangent calculator outputs a timing error &tgr; based on the correlation data series SMi.