Devices and methods for data transmissions

1. A wireless communication method by a first wireless communication device, comprising:

transmitting, by the first wireless communication device to a second wireless communication device, a first message; and

after the first wireless communication device transmits the first message to the second wireless communication device and the first wireless communication device receives a second message relevant to the first message from the second wireless communication device, the first wireless communication device transmits a data transmission to the second wireless communication device,

wherein the second message is a pre-configured sequence or a pre-defined sequence,

wherein the second message is carried in a PUCCH format 0 or a PUCCH format 1,

wherein the second message comprises a clear to send (CTS) message, which is an acknowledgement of receiving a corresponding first massage,

wherein the CTS message indicates that the second wireless communication device has performed a successful channel access on one or more channels,

wherein the CTS message comprises a set of bits, where each bit corresponds to an outcome of channel access failure or success on a dedicated channel or a dedicated carrier,

wherein when the channel access is successful, the corresponding bit is set to a pre-defined value,

wherein a number of bits contained in the CTS message is indicated by a corresponding request to send (RTS) message,

wherein when the first wireless communication device controls the second wireless communication device to receive a first RTS on a first carrier or a first serving cell and a second RTS on a second carrier or a second serving cell, both the first RTS and the second RTS request a same CTS transmission,

wherein the first wireless communication device is configured to control the second wireless communication device to transmit a CTS message in the CTS, which contains an acknowledgement to the first RTS and the second RTS,

wherein the RTS message comprises an indication corresponding to a location of an acknowledgement bit in the CTS message,

wherein the first RTS indicates that the CTS contains 2 acknowledgement bits and an acknowledgement bit corresponding to the first RTS is located in a first bit,

wherein the second RTS indicates that the CTS contains 2 acknowledgement bits and an acknowledgement bit corresponding to the second RTS is located in a second bit.

2. The method of claim 1 , wherein the second message is used to confirm that the second wireless communication device has received the first message and the second message is requested by the first message.

3. The method of claim 1 , wherein the first message comprises a request transmission message or an RTS message.

4. The method of claim 1 , wherein the first wireless communication device comprises a base station, and the second wireless communication device comprises a user equipment, wherein the RTS message is carried in a group-common PDCCH, when the first wireless communication device controls the second wireless communication device to receive the RTS message and the RTS requesting the CTS transmission,

wherein if the second wireless communication device does not transmit the CTS message due to the channel access failure, the second wireless communication device does not transmit a scheduled uplink transmission within a third time interval,

wherein if the second wireless communication device transmits the CTS message, but does not receive an acknowledgement of the CTS message from the first wireless communication device, the second wireless communication device cancels the scheduled uplink transmission within the third time interval,

wherein the third time interval is pre-configured or pre-defined or indicated in the RTS message or in the CTS message,

wherein the third time interval has a same duration as the second time interval,

wherein the third time interval starts after the last symbol of the channel carrying the CTS message,

wherein when the second wireless communication device cancels the uplink transmission in the third time interval, the second wireless communication device cancels a part of the uplink transmission that is beyond a fourth time interval, where the fourth time interval starts after the last symbol of the channel carrying the acknowledgement of the CTS message,

wherein the second wireless communication device maintains the uplink transmission on OFDM symbols within the fourth time interval, and the second wireless communication device cancels the uplink transmission on the OFDM symbols after the fourth time interval,

wherein the fourth time interval starts after the last symbol of the channel carrying the CTS message.

5. A wireless communication method by a second wireless communication device, comprising:

receiving, by the second wireless communication device from a first wireless communication device, a first message; and

after the second wireless communication device receives the first message from the first wireless communication device and the second wireless communication device transmits a second message relevant to the first message to the first wireless communication device, the second wireless communication device receives a data transmission from the first wireless communication device,

wherein the second message is a pre-configured sequence or a pre-defined sequence,

wherein the second message is carried in a PUCCH format 0 or a PUCCH format 1, wherein the second message comprises a clear to send (CTS) message, which is an acknowledgement of receiving a corresponding first massage

wherein the CTS message indicates that the second wireless communication device has performed a successful channel access on one or more channels,

wherein the CTS message comprises a set of bits, where each bit corresponds to an outcome of channel access failure or success on a dedicated channel or a dedicated carrier,

wherein when the channel access is successful, the corresponding bit is set to a pre-defined value,

wherein a number of bits contained in the CTS message is indicated by a corresponding request to send (RTS) message,

wherein when the second wireless communication device receives a first RTS on a first carrier or a first serving cell and a second RTS on a second carrier or a second serving cell, both the first RTS and the second RTS request a same CTS transmission,

wherein the second wireless communication device is configured to transmits a CTS message in the CTS, which contains an acknowledgement to the first RTS and the second RTS,

wherein the RTS message comprises an indication corresponding to a location of an acknowledgement bit in the CTS message,

wherein the first RTS indicates that the CTS contains 2 acknowledgement bits and an acknowledgement bit corresponding to the first RTS is located in a first bit,

wherein the second RTS indicates that the CTS contains 2 acknowledgement bits and an acknowledgement bit corresponding to the second RTS is located in a second bit.

6. The method of claim 5 , wherein the second message is used to confirm that the second wireless communication device has received the first message and/or the second message is requested by the first message.

7. The method of claim 5 , wherein the first message comprises a request transmission message or an RTS message.

8. The method of claim 5 , wherein the first wireless communication device comprises a base station, and the second wireless communication device comprises a user equipment, wherein the RTS message is carried in a group-common PDCCH, when the second wireless communication device receives the RTS message and the RTS requesting the CTS transmission,

wherein if the second wireless communication device does not transmit the CTS message due to the channel access failure, the second wireless communication device does not transmit a scheduled uplink transmission within a third time interval,

wherein if the second wireless communication device transmits the CTS message, but does not receive an acknowledgement of the CTS message from the first wireless communication device, the second wireless communication device cancels the scheduled uplink transmission within the third time interval,

wherein the third time interval is pre-configured or pre-defined or indicated in the RTS message or in the CTS message,

wherein the third time interval has a same duration as the second time interval,

wherein the third time interval starts after the last symbol of the channel carrying the CTS message,

wherein when the second wireless communication device cancels the uplink transmission in the third time interval, the second wireless communication device cancels a part of the uplink transmission that is beyond a fourth time interval, where the fourth time interval starts after the last symbol of the channel carrying the acknowledgement of the CTS message,

wherein the second wireless communication device maintains the uplink transmission on OFDM symbols within the fourth time interval, and the second wireless communication device cancels the uplink transmission on the OFDM symbols after the fourth time interval,

wherein the fourth time interval starts after the last symbol of the channel carrying the CTS message.

9. A first wireless communication device, comprising:

a memory;

a transceiver; and

a processor coupled to the memory and the transceiver;

wherein the processor is configured to control the transceiver to transmit to a second wireless communication device, a first message; and

after the transceiver transmits the first message to the second wireless communication device and the transceiver receives a second message relevant to the first message from the second wireless communication device, the transceiver transmits a data transmission to the second wireless communication device,

wherein the second message is a pre-configured sequence or a pre-defined sequence,

wherein the second message is carried in a PUCCH format 0 or a PUCCH format 1, wherein the second message comprises a (clear to send) CTS message, which is an acknowledgement of receiving a corresponding first massage,

wherein the CTS message indicates that the second wireless communication device has performed a successful channel access on one or more channels,

wherein the CTS message comprises a set of bits, where each bit corresponds to an outcome of channel access failure or success on a dedicated channel or a dedicated carrier,

wherein when the channel access is successful, the corresponding bit is set to a pre-defined value,

wherein a number of bits contained in the CTS message is indicated by a corresponding request to send (RTS) message,

wherein when the processor controls the second wireless communication device to receive a first RTS on a first carrier or a first serving cell and a second RTS on a second carrier or a second serving cell, both the first RTS and the second RTS request a same CTS transmission,

wherein the processor is configured to control the second wireless communication device to transmit a CTS message in the CTS, which contains an acknowledgement to the first RTS and the second RTS,

wherein the RTS message comprises an indication corresponding to a location of an acknowledgement bit in the CTS message,

wherein the first RTS indicates that the CTS contains 2 acknowledgement bits and an acknowledgement bit corresponding to the first RTS is located in a first bit,

wherein the second RTS indicates that the CTS contains 2 acknowledgement bits and an acknowledgement bit corresponding to the second RTS is located in a second bit.

10. The first wireless communication device of claim 9 , wherein the second message is used to confirm that the second wireless communication device has received the first message and the second message is requested by the first message.

11. The first wireless communication device of claim 9 , wherein the first message comprises a request transmission message or an RTS message.

12. The first wireless communication device of claim 9 , wherein the first wireless communication device comprises a base station, and the second wireless communication device comprises a user equipment, wherein the RTS message is carried in a group-common PDCCH, when the first wireless communication device controls the second wireless communication device to receive the RTS message and the RTS requesting the CTS transmission,

wherein if a transceiver of the second wireless communication device does not transmit the CTS message due to the channel access failure, the transceiver of the second wireless communication device does not transmit a scheduled uplink transmission within a third time interval,

wherein if the transceiver of the second wireless communication device transmits the CTS message, but does not receive an acknowledgement of the CTS message from the transceiver, a processor of the second wireless communication device cancels the scheduled uplink transmission within the third time interval,

wherein the third time interval is pre-configured or pre-defined or indicated in the RTS message or in the CTS message,

wherein the third time interval has a same duration as the second time interval,

wherein the third time interval starts after the last symbol of the channel carrying the CTS message,

wherein when the processor of the second wireless communication device cancels the uplink transmission in the third time interval, the processor of the second wireless communication device cancels a part of the uplink transmission that is beyond a fourth time interval, where the fourth time interval starts after the last symbol of the channel carrying the acknowledgement of the CTS message,

wherein the processor of the second wireless communication device maintains the uplink transmission on OFDM symbols within the fourth time interval, and the processor of the second wireless communication device cancels the uplink transmission on the OFDM symbols after the fourth time interval,

wherein the fourth time interval starts after the last symbol of the channel carrying the CTS message.

13. A second wireless communication device, comprising:

a memory;

a transceiver; and

a processor coupled to the memory and the transceiver;

wherein the processor is configured to control the transceiver to receive from a first wireless communication device, a first message; and

after the transceiver receives the first message from the first wireless communication device and the transceiver transmits a second message relevant to the first message to the first wireless communication device, the transceiver receives a data transmission from the first wireless communication device,

wherein the second message is a pre-configured sequence or a pre-defined sequence,

wherein the second message is carried in a PUCCH format 0 or a PUCCH format 1, wherein the second message comprises a clear to send (CTS) message, which is an acknowledgement of receiving a corresponding first massage,

wherein the CTS message indicates that the processor has performed a successful channel access on one or more channels,

wherein the CTS message comprises a set of bits, where each bit corresponds to an outcome of channel access failure or success on a dedicated channel or a dedicated carrier,

wherein when the channel access is successful, the corresponding bit is set to a pre-defined value,

wherein a number of bits contained in the CTS message is indicated by a corresponding request to send (RTS) message,

wherein when the transceiver receives a first RTS on a first carrier or a first serving cell and a second RTS on a second carrier or a second serving cell, both the first RTS and the second RTS request a same CTS transmission,

wherein the transceiver is configured to transmits a CTS message in the CTS, which contains an acknowledgement to the first RTS and the second RTS,

wherein the RTS message comprises an indication corresponding to a location of an acknowledgement bit in the CTS message;

wherein the first RTS indicates that the CTS contains 2 acknowledgement bits and an acknowledgement bit corresponding to the first RTS is located in a first bit,

wherein the second RTS indicates that the CTS contains 2 acknowledgement bits and an acknowledgement bit corresponding to the second RTS is located in a second bit.

14. The second wireless communication device of claim 13 , wherein the second message is used to confirm that the transceiver has received the first message and the second message is requested by the first message.

15. The second wireless communication device of claim 13 , wherein the first message comprises a request transmission message or an RTS message.

16. The second wireless communication device of claim 13 , wherein the first wireless communication device comprises a base station, and the second wireless communication device comprises a user equipment, wherein the RTS message is carried in a group-common PDCCH, when transceiver receives the RTS message and the RTS requesting the CTS transmission,

wherein if the transceiver does not transmit the CTS message due to the channel access failure, the transceiver does not transmit a scheduled uplink transmission within a third time interval,

wherein if the transceiver transmits the CTS message, but does not receive an acknowledgement of the CTS message from the first wireless communication device, the processor cancels the scheduled uplink transmission within the third time interval,

wherein the third time interval is pre-configured or pre-defined or indicated in the RTS message or in the CTS message,

wherein the third time interval has a same duration as the second time interval,

wherein the third time interval starts after the last symbol of the channel carrying the CTS message,

wherein when the processor cancels the uplink transmission in the third time interval, the processor cancels a part of the uplink transmission that is beyond a fourth time interval, where the fourth time interval starts after the last symbol of the channel carrying the acknowledgement of the CTS message,

wherein the processor maintains the uplink transmission on OFDM symbols within the fourth time interval, and the processor cancels the uplink transmission on the OFDM symbols after the fourth time interval,

wherein the fourth time interval starts after the last symbol of the channel carrying the CTS message.