Patent ID: 8295392

Claim:
A digital communication system, comprising: an indoor unit, placed in an indoor location, comprising a unit that generates communication data and a unit that modulates the communication data and generating an intermediate frequency (IF) signal; and an outdoor unit, placed in an outdoor location, comprising a unit that converts a signal inputted from the indoor unit to a radio signal, the indoor unit and the outdoor unit being connected by a cable, wherein the indoor unit further comprises: a frequency characteristic applying unit that applies a given frequency characteristic to a baseband signal; a unit that converts the baseband signal from a digital form into an analog form; an amplification unit that amplifies the baseband signal converted from the digital form into the analog form with a given amplification factor; and a unit that outputs an output signal of the amplification unit to the outdoor unit through the cable, and wherein the outdoor unit further comprises: a cable length detecting unit that detects a length of the cable; a unit that determines the frequency characteristic to be applied to the baseband signal and the amplification factor according to the detected length of the cable; and a unit that notifies the determined frequency characteristic and amplification factor to the frequency characteristic applying unit and the amplification unit respectively.