Communication system and communication method

A communication system having a hub station and multiple terminal stations, the hub station and the multiple terminal stations communicating at the same time using the same channel, wherein:

• the hub station comprises
• a modulator that generates a transmission signal including a prescribed known signal when transmitting a signal to one of the terminal stations among the multiple terminal stations,
• a filter that generates a cancellation signal for cancelling, regarding the transmission signal, an interference signal due to a signal to be transmitted to another of the terminal stations,
• a combiner that generates a combined signal by combining the transmission signal and the cancellation signal,
• a transmitter that transmits the combined signal, and
• an updater that calculates an adaptive filter minimizing a power of an error signal between the prescribed known signal and the known signal included in the combined signal received by the one of the terminal stations, based on the error signal and the interference signal;
• each of the terminal stations comprises
• a calculator that calculates the error signal,
• a generator that generates the prescribed known signal for the other of the terminal stations associated with the interference signal, the prescribed known signal being included in the interference signal,
• a calculator that calculates a correction amount of a filter coefficient in the adaptive filter based on the calculated error signal and the generated known signal included in the interference signal, and
• a transmitter that transmits the correction amount;
• and
• the updater calculates the filter coefficient such that the power of the error signal is minimized based on the correction amount;
• and
• the filter generates the cancellation signal by performing a filtering process using the filter coefficient on the signal to be transmitted to the other of the terminal stations.