| 摘要 |
PURPOSE: An RF(Radio Frequency) of a CDMA(Code Division Multiple Access) mobile communication base station system, is provided to digitally modulate baseband signals converted to band spread signals by each FA, by using an identical path for 3FA(Frequency Assignment)-RF, and to digitally combine the modulated signals by each FA, then to sequentially up-convert the combined signals to IFs(Intermediate Frequencies) and RFs. CONSTITUTION: Channel cards(11,12,13) respectively supply I/Q(Inphase/Quadrature) channel baseband signals for multi-FA(Frequency Assignment). A digital signal processing unit(100) performs digital modulation for the I/Q channel baseband signals by each FA supplied from the channel cards(11,12,13) by FAs. And the digital signal processing unit(100) combines each digital-modulated FA digital modulation signal, and converts the combined multi-FA digital modulation signals into analog signals. An analog frequency up-converting unit(110) performs the first up-conversion for multi-FA signals converted to analog signals in the digital signal processing unit(100) to IFs(Intermediate Frequencies), and performs the second up-conversion for the first up-converted IF signals to transmission frequencies, for transmission. A transmission unit(90) amplifies the transmission frequency signals which are second up-converted in the analog frequency up-converting unit(110) to an optional transmission output level, and delivers the amplified signals through a transmission antenna. |
