Communication system, base station device and communication terminal device

Abstract

A signal is transmitted and received between a base station device and a communication terminal device that are included in a communication system, through a multi-element antenna including a plurality of antenna elements. At least one of the base station device and the communication terminal device includes a PHY processing unit that is a calibration unit that performs calibration of phases and amplitudes of beams formed by the antenna elements when the signal is transmitted and received. The PHY processing unit obtains a correction value for the phases and the amplitudes of the beams in the respective antenna elements so that the phases and the amplitudes of the beams are identical among the antenna elements, and performs the calibration based on the obtained correction value.

1 . A communication system comprising
 a base station device and a communication terminal device between which a signal is transmitted and received through a multi-element antenna including a plurality of antenna elements,   wherein at least one of said base station device and said communication terminal device includes a calibration unit that performs calibration of phases and amplitudes of beams formed by said antenna elements when said signal is transmitted and received, and
 the calibration unit is configured to arrange a plurality of calibration reference signals to be transmitted from the plurality of antenna elements, in positions of a subframe in which neither reference signals nor physical channels are arranged, and transmit the plurality of calibration reference signals. 
   
     
     
         2 . The communication system according to  claim 1 ,
 wherein the reference signals or the physical channels are arranged in OFDM symbols that are not adjacent to each other, and   the plurality of calibration reference signals are arranged in OFDM symbols between the reference signals or between the physical channels.   
     
     
         3 . The communication system according to  claim 1 ,
 wherein the reference signals or the physical channels are arranged in OFDM symbols that are not adjacent to each other, and   when OFDM symbols in which the plurality of calibration reference signals should be arranged overlap OFDM symbols in which the reference signals or the physical channels should be arranged, the plurality of calibration reference signals are preferentially arranged in the OFDM symbols.   
     
     
         4 . The communication system according to  claim 1 ,
 wherein the reference signals or the physical channels are arranged in OFDM symbols that are not adjacent to each other, and   when OFDM symbols in which the plurality of calibration reference signals should be arranged overlap OFDM symbols in which the reference signals or the physical channels should be arranged, the reference signals or the physical channels are preferentially arranged in the OFDM symbols.   
     
     
         5 . A base station device that transmits and receives a signal through a multi-element antenna including a plurality of antenna elements, the base station device comprising
 a calibrating unit configured to perform calibration of phases and amplitudes of beams formed by the antenna elements when the signal is transmitted and received,   wherein the calibration unit is configured to arrange a plurality of calibration reference signals to be transmitted from the plurality of antenna elements, in positions of a subframe in which neither reference signals nor physical channels are arranged, and transmit the plurality of calibration reference signals.   
     
     
         6 . A communication terminal device that transmits and receives a signal through a multi-element antenna including a plurality of antenna elements, the communication terminal device comprising
 a calibrating unit configured to perform calibration of phases and amplitudes of beams formed by the antenna elements when the signal is transmitted and received,   wherein the calibration unit is configured to arrange a plurality of calibration reference signals to be transmitted from the plurality of antenna elements, in positions of a subframe in which neither reference signals nor physical channels are arranged, and transmit the plurality of calibration reference signals.