System and method for signal backup of active das master unit

A system for signal backup of active DAS master unit, comprising a state detection unit, a backup processing unit and at least two power distribution units, wherein a backup signal output port and a plurality of backup access ports with a number great than or equal to that of the power distribution units are arranged on the backup processing unit, and a backup signal input port and a plurality of radio frequency access ports with a number great than or equal to that of the power distribution units are arranged on the state detection unit;

• each of the at least two power distribution units has an input port coupled to one of a plurality of signal sources, and two output ports of which one is coupled to one of the plurality of radio frequency access ports and the other is coupled to one of the plurality of backup access ports, and the backup signal output port is coupled to the backup signal input port;
• each of the power distribution units is configured to divide a signal from the coupled signal source into a first signal accessing the coupled radio frequency access port and a second signal accessing the coupled backup access port;
• the state detection unit is configured to detect an accessing state of each of the plurality of radio frequency access ports;
• and
• the backup processing unit is configured to control each second signal to be in a backup-off state, when each of the plurality of radio frequency access ports is in an accessing-normal state, and control the second signal from the signal source coupled to the radio frequency access port in an accessing-abnormal state to access the backup signal input port, when any one of the plurality of radio frequency access ports is in the accessing-abnormal state.