Digital communication device , digital communication systems and digital communication system .

摘要

PROBLEM TO BE SOLVED: To provide a digital communication apparatus capable of improving both noise resistance and transmission efficiency.;SOLUTION: A digital communication apparatus A_k comprises: a characteristic variable filter 11 restricting a band width of a data transmission signal; signal processing parts 12 and 13 generating reception data by performing signal processing on output of the characteristic variable filter 11; and a synchronous control part 14 performing switching control of a frequency characteristic of the characteristic variable filter 11 in synchronization with a series of symbol periods of the data transmission signals input to the characteristic variable filter 11. The synchronous control part 14 switches the frequency characteristic of the characteristic variable filter 11 from a first frequency characteristic having a first passing band width to a second frequency characteristic having a second passing band width which is narrower than the first passing band width, within one symbol period of the series of symbol periods.;COPYRIGHT: (C)2013,JPO&INPIT