Terminal device, wireless communication method and integrated circuit

A wireless communication method of a terminal device, the method comprising:

• deriving an index of a channel quality indicator based on a channel state information reference resource, for a value of the channel quality indicator that is reported in a subframe n;
• and
• reporting a channel state information which comprises the channel quality indicator in the subframe n,
• wherein in a time domain, the channel state information reference resource is defined by a subframe n-nCQI_ref,
• wherein for periodic reporting of the channel state information, the nCQI_ref is a smallest value that is equal to or greater than 4, such that the subframe n-nCQI_ref corresponds to a valid subframe,
• wherein the valid subframe in a serving cell satisfies criteria which include at least a criterion(i),
• wherein the criterion (i) is stipulated that, for a radio frame for the serving cell, the valid subframe in the serving cell is a subframe that is indicated as a downlink subframe or a special subframe by an uplink-downlink configuration for the radio frame for the serving cell,
• wherein in a case where a physical downlink control channel which is used for signaling information that indicates the uplink-downlink configuration for the radio frame for the serving cell is detected, the uplink-downlink configuration for the radio frame for the serving cell is given by the information that indicates the uplink-downlink configuration for the radio frame for the serving cell,
• wherein in a case where the physical downlink control channel which is used for signaling the information that indicates the uplink-downlink configuration for the radio frame for the serving cell is not detected, the uplink-downlink configuration for the radio frame for the serving cell is same as an uplink-downlink configuration that is indicated by a higher layer parameter.

An integrated circuit incorporated in a terminal device, comprising:

• a measurement circuit configured to and/or programmed to derive an index of a channel quality indicator based on a channel state information reference resource, for a value of the channel quality indicator that is reported in a subframe n;
• and
• a transmission circuit configured to and/or programmed to report channel state information which comprises the channel quality indicator in the subframe n,
• wherein in a time domain, the channel state information reference resource is defined by a subframe n-nCQI_ref,
• wherein for periodic reporting of the channel state information, the nCQI_ref is a smallest value that is equal to or greater than 4, such that the subframe n-nCQI_ref corresponds to a valid subframe,
• wherein the valid subframe in a serving cell satisfies criteria which include at least a criterion(i),
• wherein the criterion (i) is stipulated that, for a radio frame for the serving cell, the valid subframe in a serving cell is a subframe that is indicated as a downlink subframe or a special subframe by an uplink-downlink configuration for the radio frame for the serving cell,
• wherein in a case where a physical downlink control channel which is used for signaling information that indicates the uplink-downlink configuration for the radio frame for the serving cell is detected, the uplink-downlink configuration for the radio frame for the serving cell is given by the information that indicates the uplink-downlink configuration for the radio frame for the serving cell,
• wherein in a case where the physical downlink control channel which is used for signaling the information that indicates the uplink-downlink configuration for the radio frame for the serving cell is not detected, the uplink-downlink configuration for the radio frame for the serving cell is same as an uplink-downlink configuration that is indicated by a higher layer parameter.