Enhanced scheduling information transmission in a heterogeneous network
View Patent ↗In a heterogeneous network environment where both high and low power nodes are sharing the same channel/frequency, explicit signaling in a downlink control message is used to select whether scheduling information SI is to be transmitted by a user equipment UE with a data payload or without a data payload. For the case where the selection is that SI is to be transmitted with a data payload, the downlink control message is used for the UE to select a transport format combination TFC for transmission of the SI with the data payload. Else for the case where the selection is that SI is to be transmitted without a data payload, the downlink control message is used for the UE to select transmit power for the transmission of the SI without the data payload.
1. A method, comprising:
selecting, by circuitry using explicit signaling in a downlink control message, whether user equipment is to transmit scheduling information with a data payload or without a data payload;
using, by the circuitry when the user equipment is to transmit the scheduling information with the data payload, the downlink control message for the user equipment to select a transport format combination for transmission of the scheduling information with the data payload; and
using, by the circuitry when the user equipment is to transmit the scheduling information without the data payload, the downlink control message for the user equipment to select a transmit power for transmission of the scheduling information without the data payload, wherein
the user equipment autonomously switches from transmission of the scheduling information with the data payload to transmission of the scheduling information without the data payload when a power backoff value is larger than a serving grant power for the user equipment,
the power backoff value is indicated by the downlink control message and the power backoff value is used for the user equipment to select the transport format combination, and
the transmit power for the transmission of the scheduling information without the data payload, after the autonomous switching by the user equipment, is not based on a transmit power for a resource grant by a serving node of the user equipment as indicated by downlink radio resource control signaling.
2. The method according to claim 1 , wherein when the user equipment is to transmit the scheduling information without a data payload,
the downlink control message on a scheduling information control channel, or an indication on a non-serving relative grant channel, indicates whether the user equipment is to follow a relative power control indication from a non-serving cell.
3. The method according to claim 1 , further comprising:
using, by the circuitry, an indication on a relative power control channel to step up or step down the transmit power for the transmission of the scheduling information, wherein
a number of different relative power control channels varies depending on whether the scheduling information is to be transmitted with the data payload or without the data payload.
4. The method according to claim 1 , wherein the user equipment further switches between transmission of the scheduling information with the data payload and transmission of the scheduling information without the data payload according to implicit signaling on a relative grant channel associated with the respective transmission of scheduling information with the data payload or without the data payload.
5. The method according to claim 1 , wherein the transmit power for the transmission of the scheduling information without the data payload, after the autonomous switching by the user equipment, is based on a transmit power for a resource grant by a serving node of the user equipment as indicated by downlink radio resource control signaling.
6. The method according to claim 5 , wherein an indication of the downlink radio resource control signaling is implicit.
7. The method according to claim 1 , wherein when the circuitry is part a serving node that serves the user equipment, the serving node:
sends the downlink control message to the user equipment; and either
sets bit values in the downlink message so that the scheduling information is transmitted with the data payload; or
sets bit values in the downlink message so that the scheduling information is transmitted without the data payload.
8. The method according to claim 1 , wherein when the circuitry is part of the user equipment, the circuitry:
receives from a serving node the downlink control message; and either
uses bit values in the downlink message to select the transport format combination for transmission of the scheduling information with the data payload; or
uses bit values in the downlink message to select the transmit power for transmission of the scheduling information without the data payload.
9. An apparatus, comprising:
circuitry; and
a memory storing computer instructions that, when executed by the circuitry, cause the circuitry to:
select, using explicit signaling in a downlink control message, whether user equipment is to transmit scheduling information with a data payload or without a data payload;
use, when the user equipment is to transmit the scheduling information with the data payload, the downlink control message for the user equipment to select a transport format combination for transmission of the scheduling information with the data payload; and
use, when the user equipment is to transmit the scheduling information without the data payload, the downlink control message for the user equipment to select a transmit power for transmission of the scheduling information without the data payload, wherein
the user equipment autonomously switches from transmission of the scheduling information with the data payload to transmission of the scheduling information without the data payload when a power backoff value is larger than a serving grant power for the user equipment,
the power backoff value is indicated by the downlink control message and the power backoff value is used for the user equipment to select the transport format combination, and
the transmit power for the transmission of the scheduling information without the data payload, after the autonomous switching by the user equipment, is not based on a transmit power for a resource grant by a serving node of the user equipment as indicated by downlink radio resource control signaling.
10. The apparatus according to claim 9 , wherein when the user equipment is to transmit the scheduling information without the data payload,
the downlink control message on a scheduling information control channel, or an indication on a non-serving relative grant channel, indicates whether the user equipment is to follow a relative power control indication from a non-serving cell.
11. The apparatus according to claim 9 , wherein
the circuitry is further configured to use an indication on a relative power control channel to step up or step down the transmit power for the transmission of the scheduling information, and
a number of different relative power control channels varies depending on whether the scheduling information is to be transmitted with the data payload or without the data payload.
12. The apparatus according to claim 9 , wherein the circuitry is further configured to switch between transmission of the scheduling information with the data payload and without the data payload according to implicit signaling on a relative grant channel associated with the respective transmission of scheduling information with the data payload or without the data payload.
13. The apparatus according to claim 9 , wherein the transmit power for the transmission of the scheduling information without the data payload, after the autonomous switching by the user equipment, is based on a transmit power for a resource grant by a serving node of the user equipment as indicated by downlink radio resource control signaling.
14. The apparatus according to claim 13 , wherein an indication of the downlink radio resource control signaling is implicit.
15. The apparatus according to claim 9 , wherein the apparatus further comprises a serving node including the circuitry, the serving node serving of the user equipment, and the serving node:
sends the downlink control message to the user equipment; and either
sets bit values in the downlink message so that the scheduling information is transmitted with the data payload; or
sets bit values in the downlink message so that the scheduling information is transmitted without the data payload.
16. The apparatus according to claim 9 , wherein the apparatus comprises the user equipment, the user equipment includes the circuitry, and the user equipment:
receives from a serving node the downlink control message; and either
uses bit values in the downlink message to select the transport format combination for transmission of the scheduling information with the data payload; or
uses bit values in the downlink message to select the transmit power for transmission of the scheduling information without the data payload.
17. A non-transitory computer readable memory storing a computer program which, when executed by at least one processor, causes the at least one processor to:
select, using explicit signaling in a downlink control message, whether user equipment is to transmit scheduling information with a data payload or without a data payload;
use, when the user equipment is to transmit the scheduling information with the data payload, the downlink control message for the user equipment to select a transport format combination for transmission of the scheduling information with the data payload; and
use, when the user equipment is to transmit the scheduling information without the data payload, the downlink control message for the user equipment to select a transmit power for transmission of the scheduling information without the data payload, wherein
the user equipment autonomously switches from transmission of the scheduling information with the data payload to transmission of the scheduling information without the data payload when a power backoff value is larger than a serving grant power for the user equipment,
the power backoff value is indicated by the downlink control message and the power backoff value is used for the user equipment to select the transport format combination, and
the transmit power for the transmission of the scheduling information without the data payload, after the autonomous switching by the user equipment, is not based on a transmit power for a resource grant by a serving node of the user equipment as indicated by downlink radio resource control signaling.
18. The non-transitory computer readable memory according to claim 17 , further wherein when the user equipment is to transmit the scheduling information without the data payload,
the downlink control message on a scheduling information control channel, or an indication on a non-serving relative grant channel, indicates whether the user equipment is to follow a relative power control indication from a non-serving cell.