| 摘要 |
PURPOSE:To prevent the transmission from being affected from an echo and group delay distortion caused in a data transmission line path by using plural carriers for the transmission of data information through data transmission and data reception frequency bands. CONSTITUTION:Transmission data are inputted from a data interface section 100 and a timing generating section 500 inputs a 4-bit parallel signal to each of modulation sections 300-347 according to a predetermined clock. Let a phase modulation speed in the modulation sections 300-347 be 25 baud, data from the interface section 100 are received by using a clock in the unit of 1/25s for data communication in 4800BPS. Similarly a generating section 200 generates a carrier modulated by the 25 baud 4-phase bias system as a pilot signal. A pilot tone and 48 kinds of carriers phase-modulated by the modulation sections 300-347 are synthesized by a synthesis section 400 and the result is sent via an interface section 600. |
