Apparatus and methods for relay-assisted uplink communication
A relay device for supporting communications between a terminal device and a base station in a wireless communications system is described. The relay device comprises a transceiver arranged to at least receive an access request message from the terminal device; and a control processor operably coupled to the transceiver and arranged to process the access request message, extract information and determine therefrom a power delta value that is not based on a determination of pathloss between the relay device and the terminal device, generate a control element comprising the power delta value; and for relaying at least the control element to the base station. The control processor is further arranged to receive subsequently at least one physical uplink channel message from the terminal device wherein a transmit power level of the at least one physical uplink channel message is based at least on the power delta value.
1. A terminal device arranged to communicate with a base station via a relay device in a wireless communications system, the terminal device comprising:
a transmitter arranged to transmit an access request message to the base station;
a receiver arranged to receive an access request grant response from the base station; and
a control processor operably coupled to the receiver and arranged to:
process the access request grant response;
extract transmit power control information therefrom for transmissions to the relay device;
generate and transmit a message-3 transmission at a first power level based on the transmit power control information;
transmit subsequently a message to the relay device at a power level based on the first power level of the message-3 transmission on at least one physical uplink channel message.
2. The terminal device of claim 1 wherein the at least one physical uplink channel message is transmit on at least one of: a physical uplink shared channel (PUSCH), a physical uplink control channel (PUCCH).
3. The terminal device of claim 2 wherein a power level of the message transmitted on the PUCCH or PUSCH is additionally based on at least a part of content of a received medium access control (MAC) radio access response (RAR) message.
4. The terminal device of claim 2 wherein a power level of the message transmitted on the PUCCH or PUSCH is additionally based on accumulated transmit power control commands received from the base station.
5. The terminal device of claim 2 wherein a power level of the message transmitted on the PUCCH is additionally based on at least one open loop parameter.
6. The terminal device of claim 5 wherein the at least one open loop parameter comprises at least one open loop common power delta parameter based on a format of the PUCCH.
7. The terminal device of claim 5 wherein the at least one open loop parameter comprises at least one open loop common power delta parameter based on a number of bits used to encode at least one of: channel quality information (CQI), at least one hybrid automatic repeat request (HARQ) message.
8. The terminal device of claim 2 wherein the transmit power level of the PUSCH message is additionally based on an access request grant message of a PUSCH resource.
9. The terminal device of claim 1 wherein a power level of the message-3 transmission is not based on a determination of pathloss between the relay device and the terminal device.
10. The terminal device of claim 1 wherein the access request message transmit to the base station comprises one from a set of access preambles that indicate relay device uplink assistance is required.
11. An integrated circuit for a terminal device arranged to communicate with a base station via a relay device in a wireless communications system, the integrated circuit comprising:
a control processor arranged to:
transmit an access request message to the base station;
receive an access request grant response from the base station;
process the access request grant response and extract therefrom transmit power control information for transmissions to the relay device;
generate and transmit a message-3 transmission at a first power level based on the transmit power control information;
transmit subsequently a message to the relay device at a power level based on the first power level of the message-3 transmission on at least one physical uplink channel message.
12. A method for a terminal device arranged to communicate with a base station via a relay device in a wireless communications system, the method comprising:
transmitting an access request message to the base station;
receiving an access request grant response from the base station;
processing the access request grant response and extract therefrom transmit power control information for transmissions to the relay device;
generating and transmit a message-3 transmission at a first power level based on the transmit power control information; and
transmitting subsequently a message to the relay device at a power level based on the first power level of the message-3 transmission on at least one physical uplink channel message.
13. A non-transitory computer program product comprising executable program code to wirelessly communicate data from a terminal device to a base station via a relay device, the executable program code operable for, when executed at the terminal device, performing the method of claim 12 .
14. A wireless communication system comprising:
at least one terminal device;
at least one base station; and
at least one relay device for supporting communications between the at least one terminal device and the at least one base station, the at least one terminal device comprising:
a transmitter arranged to transmit an access request message to the base station;
a receiver arranged to receive an access request grant response from the base station; and
a control processor operably coupled to the receiver and arranged to:
process the access request grant response;
extract transmit power control information therefrom for transmissions to the relay device;
generate and transmit a message-3 transmission at a first power level based on the transmit power control information; and
transmit subsequently a message to the relay device at a power level based on the first power level of the message-3 transmission on at least one physical uplink channel message.
15. A relay device for supporting communications between a terminal device and a base station in a wireless communications system, the relay device comprising:
a transceiver; and
a control processor operably coupled to the transceiver and arranged to:
process a received access request message from the terminal device;
extract information and determine therefrom a power delta value that is not based on a determination of pathloss between the relay device and the terminal device;
generate a control element comprising the power delta value; and
relay at least the control element to the base station;
receive subsequently a message-3 transmission from the terminal device at a received power level based on the relayed control element;
receive subsequently a message from the terminal device on at least one physical uplink channel message from the terminal device wherein a transmit power level of the at least one physical uplink channel is at substantially the same power as the received message-3 transmission.
16. An integrated circuit for a relay device supporting communications between a terminal device and a base station in a wireless communications system, the integrated circuit:
a control processor arranged to:
process a received access request message from the terminal device;
extract information and determine therefrom a power delta value that is not based on a determination of pathloss between the relay device and the terminal device;
generate a control element comprising the power delta value; and
relay at least the control element to the base station;
receive subsequently a message-3 transmission from the terminal device at a received power level based on the relayed control element;
receive subsequently a message from the terminal device on at least one physical uplink channel message from the terminal device wherein a transmit power level of the at least one physical uplink channel is at substantially the same power as the received message-3 transmission.
17. A method of wirelessly communicating data from a terminal device to a base station via a relay device, the method comprising, at the relay device:
receiving an access request message from the terminal device;
processing a received access request message from the terminal device;
extracting information and determine therefrom a power delta value that is not based on a determination of pathloss between the relay device and the terminal device;
generating a control element comprising the power delta value; and
relaying at least the control element to the base station;
receiving subsequently a message-3 transmission from the terminal device at a received power level based on the relayed control element;
receiving subsequently a message from the terminal device on at least one physical uplink channel message from the terminal device wherein a transmit power level of the at least one physical uplink channel is at substantially the same power as the received message-3 transmission.
18. A non-transitory computer program product comprising executable program code to wirelessly communicating data from a terminal device to a base station via a relay device, the executable program code operable for, when executed at the relay device, performing the method of claim 17 .