Framing, scheduling, and synchronization in wireless systems
A WTRU may receive downlink control information (DCI) indicating a start of a frame. The DCI may be received on a control channel, such as the Physical Downlink Control Channel (PDCCH) from an eNB, base station, AP, or other infrastructure equipment operating in a wireless communications system. The WTRU may decode the DCI and may determine a transmit time interval (TTI) duration, which may be expressed in terms of an integer number of basic time intervals (BTIs). The WTRU may determine a downlink (DL) transmission portion and assignment and an uplink (UL) transmission portion and UL grant based on the received DCI. Additionally, the WTRU may determine the start of the UL portion based on an offset (t offset ). The WTRU may receive data in a DL portion of the frame and may transmit in an UL portion of the frame based on the determined UL grant and TTI duration.
1. A method performed by a wireless transmit/receive unit (WTRU), the method comprising:
receiving a first downlink control information (DCI) from a base station, the first DCI comprising an indication of one or more downlink symbols and an indication of one or more uplink symbols;
receiving a second DCI from the base station, the second DCI being received in at least one of the one or more downlink symbols, the second DCI comprising information indicating resources for an uplink transmission, a starting symbol for the uplink transmission, and a number of symbols corresponding to a duration of the uplink transmission; and
sending the uplink transmission to the base station, wherein the uplink transmission is sent in accordance with the resources, the starting symbol, and the number of symbols indicated by the second DCI, and the uplink transmission is sent in at least one of the one or more uplink symbols indicated by the first DCI.
2. The method of claim 1 , wherein the second DCI is indicative of a sub-carrier spacing to be used for the uplink transmission.
3. The method of claim 1 , wherein the uplink transmission includes hybrid automatic repeat request (HARD) ACK/NACK information.
4. The method of claim 1 , further comprising:
receiving a third DCI from the base station, the third DCI comprising an indication of a second set of one or more downlink symbols and an indication of a second set one or more uplink symbols;
receiving a fourth DCI from the base station, the fourth DCI being received in at least one of the second set of one or more downlink symbols, the second DCI comprising information indicating resources for a downlink transmission, a starting symbol for the downlink transmission, and a number of symbols corresponding to a duration of the downlink transmission; and
receiving the downlink transmission from the base station, wherein the downlink transmission is received in accordance with the resources, the starting symbol, and the number of symbols indicated by the fourth DCI.
5. The method of claim 4 , wherein the fourth DCI indicates timing information for transmission of hybrid automatic repeat request (HARQ) ACK/NACK information for the downlink transmission.
6. The method of claim 5 , wherein the timing information is indicated as an offset value.
7. The method of claim 5 , wherein the fourth DCI indicates resources for transmitting the HARQ ACK/NACK information for the downlink transmission.
8. The method of claim 1 , wherein the first DCI is indicative of a timing gap between the one or more downlink symbols and the one or more uplink symbols.
9. A wireless transmit/receive unit (WTRU) comprising:
a processor;
a transmitter; and
a receiver,
the processor and the receiver configured to:
receive a first downlink control information (DCI) from a base station, the first DCI comprising an indication of one or more downlink symbols and an indication of one or more uplink symbols; and
receive a second DCI from the base station, the second DCI being received in at least one of the one or more downlink symbols, the second DCI comprising information indicating resources for an uplink transmission, a starting symbol for the uplink transmission, and a number of symbols corresponding to a duration of the uplink transmission, and
the processor and the transmitter configured to send the uplink transmission to the base station, wherein the uplink transmission is sent in accordance with the resources, the starting symbol, and the number of symbols indicated by the second DCI, and the uplink transmission is sent in at least one of the one or more uplink symbols indicated by the first DCI.
10. The WTRU of claim 9 , wherein the second DCI is indicative of a sub-carrier spacing to be used for the uplink transmission.
11. The WTRU of claim 9 , wherein the uplink transmission includes hybrid automatic repeat request (HARD) ACK/NACK information.
12. The WTRU of claim 9 , wherein the processor and the receiver are further configured to:
receive a third DCI from the base station, the third DCI comprising an indication of a second set of one or more downlink symbols and an indication of a second set one or more uplink symbols;
receive a fourth DCI from the base station, the fourth DCI being received in at least one of the second set of one or more downlink symbols, the second DCI comprising information indicating resources for a downlink transmission, a starting symbol for the downlink transmission, and a number of symbols corresponding to a duration of the downlink transmission; and
receive the downlink transmission from the base station, wherein the downlink transmission is received in accordance with the resources, the starting symbol, and the number of symbols indicated by the fourth DCI.
13. The WTRU of claim 12 , wherein the fourth DCI indicates timing information for transmission of hybrid automatic repeat request (HARQ) ACK/NACK information for the downlink transmission.
14. The WTRU of claim 13 , wherein the timing information is indicated as an offset value.
15. The WTRU of claim 13 , wherein the fourth DCI indicates resources for transmitting the HARQ ACK/NACK information for the downlink transmission.
16. The WTRU of claim 9 , wherein the first DCI is indicative of a timing gap between the one or more downlink symbols and the one or more uplink symbols.
17. A base station (BS) comprising:
a processor;
a transmitter; and
a receiver,
the processor and the transmitter configured to:
transmit a first downlink control information (DCI) to a wireless transmit/receive unit (WTRU), the first DCI comprising an indication of one or more downlink symbols and an indication of one or more uplink symbols; and
transmit a second DCI to the WTRU, the second DCI being transmitted in at least one of the one or more downlink symbols, the second DCI comprising information indicating resources for an uplink transmission, a starting symbol for the uplink transmission, and a number of symbols corresponding to a duration of the uplink transmission, and
the processor and the receiver configured to receive the uplink transmission from the WTRU, wherein the uplink transmission is received in accordance with the resources, the starting symbol, and the number of symbols indicated by the second DCI, and the uplink transmission is sent in at least one of the one or more uplink symbols indicated by the first DCI.
18. The BS of claim 17 , wherein the second DCI is indicative of a sub-carrier spacing to be used for the uplink transmission.
19. The BS of claim 17 , wherein the uplink transmission includes hybrid automatic repeat request (HARD) ACK/NACK information.
20. The BS of claim 17 , wherein the processor and the transmitter are further configured to:
transmit a third DCI to the WTRU, the first DCI comprising an indication of a second set of one or more downlink symbols and an indication of a second set one or more uplink symbols;
transmit a fourth DCI to the WTRU, the fourth DCI being transmitted in at least one of the second set of one or more downlink symbols, the second DCI comprising information indicating resources for a downlink transmission, a starting symbol for the downlink transmission, and a number of symbols corresponding to a duration of the downlink transmission; and
transmit the downlink transmission to the WTRU, wherein the downlink transmission is transmitted in accordance with the resources, the starting symbol, and the number of symbols indicated by the fourth DCI.