| 摘要 |
PROBLEM TO BE SOLVED: To provide a digital transmission apparatus in which the sufficient suppression of radio interference to an adjacent channel can be easily acquired and to perform transmission in which a multi-carrier signal is assigned to a LOW side band by decreasing a level at the side edge of a high frequency and a multi-carrier signal is assigned to a HIGH side band by decreasing a level at the side edge of a low frequency to decrease the quantity of adjacent interference out of the band. SOLUTION: In the multi-stage relay transmission system based on multi- carrier modulation, a multi-carrier modulated signal of a sequence (a) is assigned to the upside in an M-th channel band on a relay stage due to a microwave band by reducing the prescribed number of carriers on the side of the high frequency, and a multi-carrier modulated signal of a sequence (b) is assigned to the downside in the relevant M-th channel band by reducing the prescribed number of carriers on the side of the low frequency. Then, such signals are multiplexed to perform multi-stage relay transmission. COPYRIGHT: (C)2003,JPO |
