Terminal device, base station apparatus and communication method
There is provided a terminal device that communicates with a base station apparatus. The device includes: a higher layer processing unit that configures a discovery signal which includes cell-specific reference signals present in DwPTSs of all downlink subframes and all special subframes, a first synchronization signal present in a prescribed subframe, a second synchronization signal present in a first subframe, and one or more non-zero power CSI reference signals during a period of continuous subframes in a predetermined cell; and a reception unit that receives the discovery signal. A subframe offset between the second synchronization signal and the non-zero power CSI reference signal is independently configured for each of the non-zero power CSI reference signals.
1. A terminal device that communicates with a base station apparatus, the terminal device comprising:
measurement circuitry configured to measure reference signal received power (RSRP) and/or received signal strength indicator (RSSI), based on a discovery signal which includes cell-specific reference signals present in downlink subframes and in Downlink Pilot Time Slots (DwPTSs) of special subframes, a primary synchronization signal present in a prescribed subframe, a secondary synchronization signal present in a first subframe, and one or more Channel State Information (CSI) reference signals during a period of consecutive subframes in a predetermined cell; and
reception circuitry configured to receive the discovery signal,
wherein the reception circuitry is further configured to receive Radio Resource Control (RRC) signaling which indicates, for each of the one or more CSI reference signals, (a) a physical cell ID of the predetermined cell and (b) a subframe offset between (i) the secondary synchronization signal and (ii) the each of the one or more CSI reference signals.
2. The terminal device according to claim 1 ,
wherein a subframe in which the CSI reference signal is present is determined based on a subframe in which the secondary synchronization signal is present and the subframe offset.
3. The terminal device according to claim 1 ,
wherein a subframe in which the CSI reference signal is present is a subframe which is the same as or subsequent to the subframe in which the secondary synchronization signal is present during the period of the consecutive subframes.
4. The terminal device according to claim 1 , further comprising:
higher layer processing circuitry configured to receive information indicating the period of the consecutive subframes.
5. The terminal device according to claim 1 , further comprising:
higher layer processing circuitry configured to receive independently configured parameters for generating a pseudo-random sequence for each of the CSI reference signals.
6. The terminal device according to claim 1 ,
wherein it is assumed by the terminal device that a signal and a channel except for the discovery signal are not transmitted by the base station apparatus in the predetermined cell in a case where at least the predetermined cell is not activated.
7. A base station apparatus that communicates with a terminal device, the base station apparatus comprising:
generation circuitry configured to generate a discovery signal for measurement of (a) reference signal received power (RSRP) and/or (b) received signal strength indicator (RSSI), wherein the discovery signal includes cell-specific reference signals present in downlink subframes and in Downlink Pilot Time Slots (DwPTSs) of special subframes, a primary synchronization signal present in a prescribed subframe, a secondary synchronization signal present in a first subframe, and one or more Channel State Information (CSI) reference signals during a period of consecutive subframes in a predetermined cell; and
transmission circuitry configured to transmit the discovery signal,
wherein the transmission circuitry is further configured to transmit Radio Resource Control (RRC) signaling which indicates, for each of the one or more CSI reference signals, (a) a physical cell ID of the predetermined cell and (b) a subframe offset between (i) the secondary synchronization signal and (ii) the each of the one or more CSI reference signals.
8. The base station apparatus according to claim 7 ,
wherein a subframe in which the CSI reference signal is present is determined based on a subframe in which the secondary synchronization signal is present and the subframe offset.
9. The base station apparatus according to claim 7 ,
wherein a subframe in which the CSI reference signal is present is a subframe which is the same as or subsequent to the subframe in which the secondary synchronization signal is present during the period of the consecutive subframes.
10. The base station apparatus according to claim 7 , further comprising:
higher layer processing circuitry configured to transmit information indicating the period of the consecutive subframes.
11. The base station apparatus according to claim 7 , further comprising:
higher layer processing circuitry configured to transmit independently configured parameters for generating a pseudo-random sequence for each of the CSI reference signals.
12. The base station apparatus according to claim 7 ,
wherein it is assumed by the terminal device that a signal and a channel except for the discovery signal are not transmitted by the base station apparatus in the predetermined cell in a case where at least the predetermined cell is not activated.
13. A method performed by a terminal device that communicates with a base station apparatus, the method comprising:
measuring reference signal received power (RSRP) and/or received signal strength indicator (RSSI), based on a discovery signal which includes cell-specific reference signals present in downlink subframes and in Downlink Pilot Time Slots (DwPTSs) of special subframes, a primary synchronization signal present in a prescribed subframe, a secondary synchronization signal present in a first subframe, and one or more Channel State information (CSI) reference signals during a period of consecutive subframes in a predetermined cell;
receiving the discovery signal; and
receiving Radio Resource Control (RRC) signaling which indicates, for each of the one or more CSI reference signals, (a) a physical cell ID of the predetermined cell and (b) a subframe offset between (i) the secondary synchronization signal and (iii) the each of the one or more CSI reference signals.
14. A method performed by a base station apparatus that communicates with a terminal device, the method comprising:
generating a discovery signal for measurement of (a) reference signal received power (RSRP) and/or (b) received signal strength indicator (RSSI), wherein the discovery signal includes cell-specific reference signals present in downlink subframes and in Downlink Pilot Time Slots (DwPTSs) of special subframes, a primary synchronization signal present in a prescribed subframe, a secondary synchronization signal present in a first subframe, and one or more Channel State Information (CSI) reference signals during a period of consecutive subframes in a predetermined cell;
transmitting the discovery signal; and
transmitting Radio Resource Control (RRC) signaling which indicates, for each of the one or more CSI reference signals, (a) a physical cell ID of the predetermined cell and (b) a subframe offset between (i) the secondary synchronization signal and (ii) the each of the one or more CSI reference signals.