Remote radio frequency unit, baseband signal processing method and system

The invention discloses a far-end radio frequency unit and a baseband signal processing method and system. Wherein the far-end radio frequency unit comprises a digital front-end chip and a transceiving chip, in a downlink stage, the digital front-end chip receives a first baseband signal from the far-end convergence unit, deframing, decompression, shaping filtering, up-sampling and data pre-distortion processing are carried out on the first baseband signal, and a second baseband signal is obtained; the transceiver chip performs digital-to-analog conversion and up-mixing processing on the second baseband signal, and sends an obtained first radio frequency signal to the terminal; and in the uplink stage, the transceiver chip receives a second radio frequency signal sent by the terminal and performs down-mixing and analog-to-digital conversion processing on the second radio frequency signal to obtain a third baseband signal, and the digital front-end chip performs down-sampling, forming filtering, compression an