Patent ID: 9020558
Filing Date: 2015-04-28
Classification: H04W

Abstract:
1. A wireless communication system for performing MIMO transmission, comprising: a terminal device configured to employ a MIMO technique on at least a transmission side; and a base station configured to communicate with the terminal device, wherein: the terminal device includes a plurality of wireless transmitters, a transmission antenna coupled to each of the wireless transmitters, and a controller configured to generate a signal to be transmitted from the antenna; the base station includes a plurality of wireless receivers, a reception antenna coupled to each of the wireless receivers, and a controller configured to generate a control signal to be transmitted to the terminal device; the terminal device is configured to hold a predetermined upper limit of power consumption; and the base station is configured to change at least one of a MIMO multiplexing number, a modulation system, and a coding rate so that communication is performed according to a communication system that can communicate at allowable transmission power of the terminal device in case where power consumption of the terminal device exceeds the upper limit upon performing the MIMO transmission at maximum transmission power according to the wireless standard, wherein: the terminal device is configured to transmit the allowable transmission power to the base station; the base station is configured to compare the received allowable transmission power with transmission power included in the control signal transmitted to the terminal device; the base station is configured to change at least one of a MIMO multiplexing number, a modulation system, and a coding rate to determine the communication system that can communicate at the allowable transmission power of the terminal device in case where the power consumption of the terminal exceeds the upper limit upon performing the MIMO transmission at the transmission power included in the control signal; the base station is configured to notify the terminal of the determined communication system; and the terminal device is configured to communicate within the upper limit of the power consumption by changing the communication system in accordance with the notification.