Transmission schemes and modes and fallback schemes for the access link of systems operating in higher frequency bands
A wireless transmit/receive unit (WTRU) configured to perform wireless communications in higher frequency bands (e.g., above 6 GHz) using a fallback scheme is provided. The WTRU includes a receiver configured to receive, in a time transmission interval (TTI), at least one control signal and a first data signal using a first beam associated with a first beam identifier (ID) and a second data signal, subsequent to the first data signal, using a second beam associated with a second beam ID different from the first beam ID, such that one of the at least one control signal indicates the second beam ID; and a processor configured to switch a receive beam of the receiver from the first beam to the second beam based on the second beam ID to receive the second data signal.
1. A wireless transmit/receive unit (WTRU) configured to perform wireless communications, the WTRU comprising:
a transceiver; and
a processor, wherein:
the transceiver and the processor are configured to receive a control signal using a first beam, the control signal comprising control information having a first format or a second format, wherein the control information comprises downlink control information (DCI);
the transceiver and the processor are further configured to, on a condition that the control information has the first format, receive a data signal using the first beam; and
the transceiver and the processor are configured to: on a condition that the control information has the second format, switch a receive beam from the first beam to a second beam identified in the control information, and receive the data signal using the second beam.
2. The WTRU of claim 1 , wherein the transceiver and the processor are further configured to receive the control signal in a control region that precedes the data signal.
3. The WTRU of claim 1 , wherein:
the processor is further configured to switch the receive beam from the first beam to a third beam indicated by a network; and
the transceiver and the processor are further configured to receive a second control signal using the third beam.
4. The WTRU of claim 1 , wherein the data signal is received after a guard period starting after the control signal.
5. The WTRU of claim 4 , wherein the guard period is indicated by the WTRU.
6. The WTRU of claim 4 , wherein the guard period is indicated in the control information having the second format.
7. The WTRU of claim 4 , wherein the guard period is based on a WTRU capability.
8. A method implemented by a wireless transmit/receive unit (WTRU), the method comprising:
receiving a control signal using a first beam, the control signal comprising control information having a first format or a second format;
receiving a data signal using the first beam, on a condition that the control information has the first format, wherein the control information comprises downlink control information (DCI); and
on a condition that the control information has the second format: switching a receive beam from the first beam to a second beam identified in the control information and receiving the data signal using the second beam.
9. The method of claim 8 , further comprising:
receiving the control signal in a control region that precedes the data signal.
10. The method of claim 8 , further comprising:
switching the receive beam from the first beam to a third beam indicated by a network; and
receiving a second control signal using the third beam.
11. The method of claim 8 , wherein the data signal is received after a guard period starting after the control signal.
12. The method of claim 11 , wherein the guard period is indicated by the WTRU.
13. The method of claim 11 , wherein the guard period is indicated in the control information having the second format.
14. The method of claim 11 , wherein the guard period is based on a WTRU capability.