Abstract: There are provided a communication system, a communication apparatus and a communication control method capable of minimizing the decline in throughput efficiently. The communication system according to the present invention includes a communication apparatus configured to employ an adaptive modulation system and a corresponding communication apparatus configured to communicate wirelessly with the communication apparatus, in which the corresponding communication apparatus receives a wireless signal from the communication apparatus, calculates the reception quality value and the bit error rate of the wireless signal, and transmits the reception quality value and the bit error rate to the communication apparatus; and the communication apparatus has a table indicating a modulation class to be chosen corresponding to the reception quality value and changes a modulation class indicated by the table based on the bit error rate.

Abstract: A radio relay apparatus 100 used in a radio communication system in which a radio base station 200 transmits abase station preamble signal at a predetermined timing includes a control unit 130 that controls a service-side radio communication unit 120S that performs radio communication with the radio terminal, the base station preamble signal being a radio signal to be used by a radio terminal to establish synchronization. The service-side radio communication unit 120S transmits a relay station preamble signal at a timing different from the predetermined timing, the relay station preamble signal being a radio signal to be used by the radio terminal to establish synchronization. The control unit 130 controls the service-side radio communication unit 120S so that at the predetermined timing, the service-side radio communication unit 120S transmits a preamble mask signal that is a radio signal to disturb the base station preamble signal.

Abstract: There are provided a communication system, a communication apparatus and a communication control method capable of minimizing the decline in throughput efficiently. The communication system according to the present invention includes a communication apparatus configured to employ an adaptive modulation system and a corresponding communication apparatus configured to communicate wirelessly with the communication apparatus, in which the corresponding communication apparatus receives a wireless signal from the communication apparatus, calculates the reception quality value and the bit error rate of the wireless signal, and transmits the reception quality value and the bit error rate to the communication apparatus; and the communication apparatus has a table indicating a modulation class to be chosen corresponding to the reception quality value and changes a modulation class indicated by the table based on the bit error rate.

Abstract: A radio relay apparatus 100 used in a radio communication system in which a radio base station 200 transmits abase station preamble signal at a predetermined timing includes a control unit 130 that controls a service-side radio communication unit 120S that performs radio communication with the radio terminal, the base station preamble signal being a radio signal to be used by a radio terminal to establish synchronization. The service-side radio communication unit 120S transmits a relay station preamble signal at a timing different from the predetermined timing, the relay station preamble signal being a radio signal to be used by the radio terminal to establish synchronization. The control unit 130 controls the service-side radio communication unit 120S so that at the predetermined timing, the service-side radio communication unit 120S transmits a preamble mask signal that is a radio signal to disturb the base station preamble signal.