A communication satellite includes user beam antennas capable of forming user beams and feeder beam antennas capable of forming feeder link beams. The communication satellite includes demultiplexing units that divide a reception signal into up-user-link signals, multiplexing units that multiplex input signals and output the signals to feeder beam antennas, and a switch that duplicates an up-user-link signal on the basis of information determined for each of the up-user link signals and indicating whether the user link signal is duplicated, generates a duplicated signal, and outputs the duplicated signal and the up-user-link signal to the multiplexing units corresponding to second beams respectively allocated to the duplicated signal and the up-user-link signal.