Communication apparatus and communication method for initial access

1. A terminal comprising:

a receiver, which in operation, receives one or more discovery reference signals (DRSs) transmitted by a base station within a channel occupancy time (COT) starting at a possible start timing that is not aligned with half a slot boundary and that is determined from one or more possible start timings; and

circuitry, which in operation, determines frame timing in response to receiving the one or more DRSs,

wherein a number of the one or more possible start timings per half a slot is different for different subcarrier spacings (SCSs).

2. The terminal of claim 1 , wherein more than one possible start timing per half a slot are determined for a subcarrier spacing (SCS).

3. The terminal of claim 1 , wherein the number of possible start timings per half a slot for a smaller SCS is greater than that for a larger SCS.

4. The terminal of claim 1 , wherein each of the one or more DRSs include a first signaling for indicating a synchronization signal block (SSB) index and a second signaling for indicating a timing offset.

5. The terminal of claim 1 , wherein each of the one or more DRSs include a signaling for indicating a candidate SSB position index.

6. The terminal of claim 1 , wherein each of the one or more DRSs include a signaling for indicating a starting position index (SPI).

7. The terminal of claim 1 , wherein a time domain position of the one or more DRSs is selected from one or more additional candidate positions corresponding to the possible start timing.

8. The terminal of claim 7 , wherein a starting index for the one or more additional candidate positions corresponding to the possible start timing is an integer multiple of X, where X is a maximum number of the one or more DRSs transmitted within a DRS transmission window.

9. A base station, comprising:

circuitry, which in operation, generates one or more discovery reference signal signals (DRSs); and

a transmitter, which in operation, transmits the one or more (DRSs) to a terminal within a channel occupancy time (COT) starting at a possible start timing that is not aligned with half a slot boundary and that is determined from one or more possible start timings,

wherein a number of the one or more possible start timing per half a slot is different for different subcarrier spacings (SCSs).

10. The base station of claim 9 , wherein the number of possible start timings per half a slot for a smaller synchronization signal block (SSB) subcarrier spacing (SCS) is greater than that for a larger SSB SCS.

11. The base station of claim 9 , wherein the transmitter transmits a reservation signal till a next half a slot boundary prior to the transmission of the one or more DRSs.

12. A communication method comprising:

obtaining, at a base station, a channel occupancy time (COT) starting at a possible start timing that is not aligned with half a slot boundary and that is determined from one or more possible start timings;

generating, at the base station, one or more discovery reference signals (DRSs) at a beginning of the COT; and

transmitting, from the base station, the one or more DRSs to a terminal,

wherein a number of the one or more possible start timing per half a slot is different for different subcarrier spacings (SCSs).

13. The communication method according to claim 12 , comprising:

receiving, at a terminal, the one or more DRSs transmitted by the base station; and

determining, at the terminal, frame timing in response to receiving the one or more DRSs.

14. The communication method according to claim 12 , comprising:

selecting, at the base station, a time domain position of the one or more DRSs from one or more additional candidate positions corresponding to the possible start timing.