| 摘要 |
PURPOSE:To decode a multidimensional code by sending out an offset at a signal point position additionally from a transmission side at the time of a symbol indicating the transmission of a frame synchronizing signal and detecting the frame synchronizing signal on a reception side based on an error quantity from a reference signal point. CONSTITUTION:When the frame synchronizing signal is sent out on the transmission side, a constant offset a is added by adders 2 and 3 to an amplitude and a phase component at a sent signal point and the signal is sent out. A synchronous detecting circuit 24 on the reception side finds the quantities of errors between the amplitude and phase component of a received signal and the amplitude and phase component of a reference signal and integrates the sum of the absolute values of the error quantities by one symbol. Then it is decided that there is the frame synchronizing signal in a symbol which is larger than a reference value among successively generated 1-symbol integral values. Only when the frame signal is found, adders 25 and 26 subtract the offset alpha from the (x) component and (y) component of the position signal at a received signal point and when no frame synchronizing signal is found, 0 is subtracted and a decision device 27 decides the received signal point to decode the multidimensional code. |
