Digital signal transmitter/receiver equipment includes a first transmitter/receiver unit that handles digital signals and a second transmitter/receiver unit connected to the first transmitter/receiver unit via a transmission line to subject a digital signal to both a modulation/demodulation process and...http://www.google.de/patents/US6021163?utm_source=gb-gplus-sharePatent US6021163 - Inter-unit digital signal transmitting method, digital signal transmitter and receiver equipment, digital signal transmitter, and digital signal receiver
