Terminal device, base station device, and communication method
A terminal device (UE) includes a reception unit configured to monitor an enhanced physical downlink control channel (EPDCCH) on a Serving cell with frame structure type 3. In a case that the terminal device detects downlink control information (DCI) in a subframe, the terminal device assumes a configuration of OFDM symbols according to a field in the DCI in the subframe. The OFDM symbols are used for downlink transmission. A demodulation reference signal (DMRS) associated with the EPDCCH is mapped in the subframe according to the configuration of the OFDM symbols.
1. A terminal device configured to communicate with a base station device, the terminal device comprising:
reception circuitry configured to monitor an enhanced physical downlink control channel (EPDCCH) on a Serving cell having a frame structure type 3 which is used for a Licensed Assisted Access (LAA) cell, wherein
the LAA cell including a plurality of subframes which are numbered serially,
the subframes being designated as one of a plurality of special subframe configurations 0 to 9,
a number of enhanced resource element groups (EREGs) included in an enhanced control channel element (ECCE) being determined by the special subframe configurations,
in a case that the terminal device detects downlink control information (DCI) in a first subframe which is one of the numbered subframes, the terminal device assumes a configuration of Orthogonal Frequency Division Multiplexing (OFDM) symbols according to a field in the DCI in the first subframe,
the OFDM symbols are used for downlink transmission,
information mapped in the first subframe indicates a number of first OFDM symbols, which are used for the downlink transmission, in a second subframe which is another one of the numbered subframes and subsequent to the first subframe, and
a demodulation reference signal (DMRS) associated with the EPDCCH is mapped in the first subframe according to the configuration of the OFDM symbols.
2. The terminal device according to claim 1 , wherein the first subframe follows one of a plurality of downlink pilot time slot (DwPTS) durations.
3. The terminal device according to claim 1 , wherein
the terminal device assumes that the number of the first OFDM symbols are used for the downlink transmission in the first subframe, and
the number is determined by a value corresponding to the field.
4. The terminal device according to claim 3 , wherein the DMRS is mapped to sixth and seventh OFDM symbols of both a first slot and a second slot in a case that the number is 14.
5. The terminal device according to claim 3 , wherein the DMRS is mapped to third and fourth OFDM symbols of both a first slot and a second slot in a case that the number is 11.
6. The terminal device according to claim 3 , wherein the DMRS is mapped to third, fourth, sixth and seventh OFDM symbols of a first slot in a case that the number is 9.
7. The terminal device according to claim 1 , wherein
the reception circuitry is further configured to receive a physical downlink shared channel (PDSCH), and
the OFDM symbols are used for reception of the PDSCH.
8. The terminal device according to claim 1 , wherein
a number of EREGs included in the ECCE is 4 in a case that the first subframe follows a downlink pilot time slot (DwPTS) duration of any of the special subframe configurations 3, 4, and 8, and
the number of EREGs included in the ECCE is 8 in a case that the first subframe follows the DwPTS duration of any of the special subframe configurations 1, 2, 6, 7, and 9.
9. A base station device configured to communicate with a terminal device, the base station device comprising:
transmission circuitry configured to transmit an enhanced physical downlink control channel (EPDCCH) on a Serving cell having a frame structure type 3 which is used for a Licensed Assisted Access (LAA) cell, wherein
the LAA cell including a plurality of subframes which are numbered serially,
the subframes being designated as one of a plurality of special subframe configurations 0 to 9,
a number of enhanced resource element groups (EREGs) included in an enhanced control channel element (ECCE) being determined by the special subframe configurations,
in a case that the terminal device detects downlink control information (DCI) in a first subframe which is one of the numbered subframes, the terminal device assumes a configuration of Orthogonal Frequency Division Multiplexing (OFDM) symbols according to a field in the DCI in the first subframe,
the OFDM symbols are used for downlink transmission,
information mapped in the first subframe indicates a number of first OFDM symbols, which are used for the downlink transmission, in a second subframe which is another one of the numbered subframes and subsequent to the first subframe, and
a demodulation reference signal (DMRS) associated with the EPDCCH is mapped in the first subframe according to the configuration of OFDM symbols.
10. The base station device according to claim 9 , wherein the first subframe follows one of a plurality of downlink pilot time slot (DwPTS) durations.
11. The base station device according to claim 9 , wherein
the terminal device assumes that the number of the first OFDM symbols are used for the downlink transmission in the first subframe, and
the number is determined by a value corresponding to the field.
12. The base station device according to claim 11 , wherein the DMRS is mapped to sixth and seventh OFDM symbols of both a first slot and a second slot in a case that the number is 14.
13. The base station device according to claim 11 , wherein the DMRS is mapped to third and fourth OFDM symbols of both a first slot and a second slot in a case that the number is 11.
14. The base station device according to claim 11 , wherein the DMRS is mapped to third, fourth, sixth and seventh OFDM symbols of a first slot in a case that the number is 9.
15. The base station device according to claim 9 , wherein
the transmission circuitry is further configured to transmit a physical downlink shared channel (PDSCH), and
the OFDM symbols are used for transmission of the PDSCH.
16. The base station device according to claim 9 , wherein
a number of EREGs included in the ECCE is 4 in a case that the first subframe follows a downlink pilot time slot (DwPTS) duration of any of the special subframe configuration 3, 4, and 8, and
the number of EREGs included in the ECCE is 8 in a case that the first subframe follows the DwPTS duration of any of the special subframe configurations 1, 2, 6, 7, and 9.
17. A communication method of a terminal device configured to communicate with a base station device, the communication method comprising the step of:
monitoring an enhanced physical downlink control channel (EPDCCH) on a Serving cell having a frame structure type 3 which is used for a Licensed Assisted Access (LAA) cell, wherein
the LAA cell including a plurality of subframes which are numbered serially,
the subframes being designated as one of a plurality of special subframe configurations 0 to 9,
a number of enhanced resource element groups (EREGs) included in an enhanced control channel element (ECCE) being determined by the special subframe configurations,
in a case that the terminal device detects downlink control information (DCI) in a first subframe which is one of the numbered subframes, the terminal device assumes a configuration of Orthogonal Frequency Division Multiplexing (OFDM) symbols according to a field in the DCI in the first subframe,
the OFDM symbols are used for downlink transmission,
information mapped in the first subframe indicates a number of first OFDM symbols, which are used for the downlink transmission, in a second subframe which is another one of the numbered subframes and subsequent to the first subframe, and
a demodulation reference signal (DMRS) associated with the EPDCCH is mapped in the first subframe according to the configuration of the OFDM symbols.
18. A communication method of a base station device configured to communicate with a terminal device, the communication method comprising the step of:
transmitting an enhanced physical downlink control channel (EPDCCH) on a Serving cell having a frame structure type 3 which is used for a Licensed Assisted Access (LAA) cell, wherein
the LAA cell including a plurality of subframes which are numbered serially,
the subframes being designated as one of a plurality of special subframe configurations 0 to 9,
a number of enhanced resource element groups (EREGs) included in an enhanced control channel element (ECCE) being determined by the special subframe configurations,
in a case that the terminal device detects downlink control information (DCI) in a first subframe which is one of the numbered subframes, the terminal device assumes a configuration of Orthogonal Frequency Division Multiplexing (OFDM) symbols according to a field in the DCI in the first subframe,
the OFDM symbols are used for downlink transmission,
information mapped in the first subframe indicates a number of first OFDM symbols, which are used for the downlink transmission, in a second subframe which is another one of the numbered subframes and subsequent to the first subframe, and
a demodulation reference signal (DMRS) associated with the EPDCCH is mapped in the first subframe according to the configuration of the OFDM symbols.