Patent ID: 8279849

Claim:
A propagation delay time adjustment method for adjusting the propagation delay time occurring within a reception circuit for each channel of a center node device configuring a 1-to-N communications system in which communication is performed between the center node device and N (N being an integer of 2 or more) individual edge node devices using a Synchronous Code Division Multiplexing method, the center node device comprising a main control section that sequentially adjusts the propagation delay times occurring within the reception circuit for each of the channels one-by-one, and each of the edge node devices comprising an auxiliary control section that controls the propagation delay time in cooperation with the main control section, the transmission delay time adjustment method comprising: transmission permission signal transmitting in which the main control section transmits a transmission permission signal in which a spreading code has been specified for the edge node device; transmission controlling in which, when the transmission permission signal is received, the auxiliary control section repeatedly transmits a sync signal that has been coded using the spreading code; reception phase controlling in which the main control section changes a reception phase of the reception circuit corresponding to the edge node device; reception validity determining in which, for a fixed signal period in a reception signal from the edge node device, the main control section determines whether or not a signal has been validly received based on a spreading demodulation output signal from the reception circuit; optimum reception phase determining in which the main control section determines the optimum reception phase for which valid reception can be made within an oscillated range of the reception phase; and reception phase setting in which the main control section sets the optimum reception phase as the reception phase for the reception circuit.