Mobile station device
View Patent ↗A mobile terminal device for performing multi-carrier communication with a base station device can improve communication quality while reducing the data amount without lowering accuracy of feedback information. In the mobile station device ( 100 ), a reception level measuring unit ( 135 ) measuring SINR as a reception level for each chunk formed by a plurality of sub-carriers according to a known signal; a control information transmission control unit ( 160 ) transmits feedback information (CQI information) based on the communication quality of each chunk to a base station device ( 200 ); a relative value calculation unit ( 150 ) calculates a relative value of MCS corresponding to the reception level between adjacent chunks from the reception level of each chunk; and a CQI information generation unit ( 155 ) generates feedback information (CQI information) from an absolute value of MCS corresponding to the reception level of the reference chunk and a relative value of MCS corresponding to the reception level between the adjacent chunks.
1. A mobile station apparatus comprising:
a calculating unit configured to calculate a channel quality indicator (CQI) value for each of groups, into which subcarriers that are consecutive in a frequency domain are divided in a predefined unit of a time domain, the CQI value representing channel quality according to a first step size, by which a range of the CQI value is divided;
a generating unit configured to generate feedback information based on the calculated CQI value for each of the groups; and
a transmitting unit configured to transmit the feedback information, wherein:
said calculating unit calculates a differential value for each of the groups, the differential value being a difference of the calculated CQI value with respect to a single CQI value which represents channel quality for all of the groups, and transforms the differential value according to a second step size, which includes a step size greater than the first step size and by which a range of the difference is divided, and
said generating unit generates the feedback information forming a data sequence, in which the single CQI value is positioned at the beginning and the differential values for the groups are positioned after the single CQI value in order of increasing frequency or decreasing frequency.
2. The mobile station apparatus according to claim 1 , wherein said transmitting unit transmits the single CQI value which represents the channel quality for all of the groups as an absolute value.
3. The mobile station apparatus according to claim 1 , further comprising a receiving unit configured to receive transmission data, which is transmitted using said groups.
4. The mobile station apparatus according to claim 1 , wherein the CQI value indicates a modulation and coding scheme (MCS).
5. A communication method comprising:
calculating a channel quality indicator (CQI) value for each of groups, into which subcarriers that are consecutive in a frequency domain are divided in a predefined unit of a time domain, the CQI value representing channel quality according to a first step size, by which a range of the CQI value is divided; and
generating feedback information based on the calculated CQI value, wherein:
a differential value for each of the groups is calculated, the differential value being a difference of the CQI value with respect to a single CQI value which represents channel quality for all of the groups, and the differential value is transformed according to a second step size, which includes a step size greater than the first step size and by which a range of the difference is divided, and
the feedback information forming a data sequence, in which the single CQI value is positioned at the beginning and the differential values for the groups are positioned after the single CQI value in order of increasing frequency or decreasing frequency.