Terminal device, base station device, and communication method using channel quality indicator (CQI) tables and modulation coding scheme (MCS) tables to determine modulation scheme
Selection of a suitable MCS improves throughput without increasing the number of pieces of control information. With RRC signaling, information on PDCCH and a CQI table that is referred to are associated with each other, and the CQI table that is referred to is determined based on information relating to the PDCCH. Thus, the CQI table that is referred to is selected at high speed. Furthermore, information relating to control information is control information that is included in the PDCCH or an ePDCCH. Furthermore, the information relating to the control information is a type of search space of the PDCCH or the ePDCCH.
1. A terminal apparatus comprising:
a DL reception unit that receives, from a base station apparatus, a Physical Downlink Shared Channel (PDSCH) and a Physical Downlink Control Channel (PDCCH),
the PDSCH includes Radio Resource Control (RRC) information that includes an indication of applicability of a second Channel Quality Indicator (CQI) table of a first CQI table and the second CQI table, and
a PDSCH demodulation unit that determines a modulation scheme which is used in the PDSCH demodulation, using at least either a first Modulation Coding Scheme (MCS) table or a second MCS table, wherein
the first MCS table is used to determine the modulation scheme if the indication is configured and the PDSCH is assigned by the PDCCH in common search space,
the first MCS table includes information relating to a first modulation scheme, the information relating to the first modulation scheme corresponds to QPSK, 16QAM, or 64QAM,
the second MCS table includes information relating to a second modulation scheme, the information relating to the second modulation scheme corresponds to QPSK, 16QAM, 64QAM, or 256QAM,
the first CQI table includes information relating to a third modulation scheme, the information relating to the third modulation scheme includes QPSK, 16QAM, or 64QAM,
the second CQI table includes information relating to a forth modulation scheme, and the information relating to the forth modulation scheme includes QPSK, 16QAM, 64QAM, and 256QAM.
2. The terminal apparatus according to claim 1 , wherein
the modulation scheme which is used in the PDSCH is based on the first MCS table, in a case where the indication is not configured.
3. A base station apparatus comprising:
a PDSCH generation unit that modulates a Physical Downlink Shared Channel (PDSCH), and
a transmission unit that transmits, to a terminal apparatus, the PDSCH and a Physical Downlink Control Channel (PDCCH);
the PDSCH includes Radio Resource Control (RRC) information that includes an indication of applicability of a second Channel Quality Indicator (CQI) table of a first CQI table and the second CQI table;
a PDSCH modulation unit that determines a modulation scheme which is used in the PDSCH modulation, using at least either a first Modulation Coding Scheme (MCS) table or a second MCS table, wherein
the first MCS table is used to determine the modulation scheme if the indication is configured and the PDSCH is assigned by the PDCCH in common search space,
the first MCS table includes information relating to a first modulation scheme, the information relating to the first modulation scheme corresponds to QPSK, 16 QAM, or 64 QAM,
the second MCS table includes information relating to a second modulation scheme, the information relating to the second modulation scheme corresponds to QPSK, 16 QAM, 64 QAM, or 256 QAM,
the first CQI table includes information relating to a third modulation scheme, the information relating to the third modulation scheme includes QPSK, 16QAM, or 64QAM,
the second CQI table includes information relating to a forth modulation scheme, and the information relating to the forth modulation scheme includes QPSK, 16QAM, 64QAM, and 256QAM.
4. The base station apparatus according to claim 3 , wherein
the modulation scheme which is used in the PDSCH is based on the first MCS table, in a case where the indication is not configured.