An antenna feed system, wherein the antenna feed system comprises an antenna unit with four ports, a first radio remote unit, RRU, a second RRU connected to the antenna unit, and a branching tower-mounted amplifier that is connected to the antenna unit, the first RRU, and the second RRU; and the first RRU has two ports (A, B), and the second RRU has four ports (A, B, C, D), wherein the antenna feed system further comprises a smart bias tee, SBT; a first port of the first RRU is connected to a first filter module of the branching tower-mounted amplifier, a second port of the first RRU is connected to a second filter module of the branching tower-mounted amplifier, a first port of the second RRU is connected to a first port of the antenna unit, a second port of the second RRU is connected to one end of the SBT, another end of the SBT is connected to a second port of the antenna unit, a third port of the antenna unit is connected to the first filter module of the branching tower-mounted amplifier, a fourth port of the antenna unit is connected to the second filter module of the branching tower-mounted amplifier, a first branching module of the branching tower-mounted amplifier is connected to a third port of the second RRU, and a second branching module of the branching tower-mounted amplifier is connected to a fourth port of the second RRU, and wherein the branching tower-mounted amplifier comprises the first filter module, the second filter module, a first amplification module, a second amplification module, and a control module; the first filter module is connected to the first amplification module, the first amplification module is connected to the control module, the control module is connected to the second amplification module, and the second amplification module is connected to the second filter module; and the branching tower-mounted amplifier further comprises: the first branching module connected to both the first filter module and the first amplification module, and the second branching module connected to both the second filter module and the second amplification module, wherein both the first branching module and the second branching module are configured to transmit a signal. wherein the antenna feed system further comprises a smart bias tee, SBT; a first port of the first RRU is connected to a first filter module of the branching tower-mounted amplifier, a second port of the first RRU is connected to a second filter module of the branching tower-mounted amplifier, a first port of the second RRU is connected to a first port of the antenna unit, a second port of the second RRU is connected to one end of the SBT, another end of the SBT is connected to a second port of the antenna unit, a third port of the antenna unit is connected to the first filter module of the branching tower-mounted amplifier, a fourth port of the antenna unit is connected to the second filter module of the branching tower-mounted amplifier, a first branching module of the branching tower-mounted amplifier is connected to a third port of the second RRU, and a second branching module of the branching tower-mounted amplifier is connected to a fourth port of the second RRU, and wherein the branching tower-mounted amplifier comprises the first filter module, the second filter module, a first amplification module, a second amplification module, and a control module; the first filter module is connected to the first amplification module, the first amplification module is connected to the control module, the control module is connected to the second amplification module, and the second amplification module is connected to the second filter module; and the branching tower-mounted amplifier further comprises: the first branching module connected to both the first filter module and the first amplification module, and the second branching module connected to both the second filter module and the second amplification module, wherein both the first branching module and the second branching module are configured to transmit a signal. the first branching module connected to both the first filter module and the first amplification module, and the second branching module connected to both the second filter module and the second amplification module, wherein both the first branching module and the second branching module are configured to transmit a signal.