Non-orthogonal multiple access signalling in LTE

1. A method of operating a non-orthogonal multiple access, NOMA, communications network, the method comprising:

receiving from each of a plurality of user equipment, UE, devices at least one radio resource measurement report;

processing the radio resource measurement reports to select a group of UE devices of the plurality of UE devices as a NOMA group;

for the UE devices in the NOMA group determining a set of control parameters for the UE devices;

informing the NOMA group UE devices of the set of control parameters, characterized in that the set of control parameters is transmitted to the NOMA group UE devices using a downlink control information message having a format specific for NOMA messaging, the downlink control information message transmitted to the NOMA group UE devices being scrambled with a temporary identifier assigned to the NOMA group.

2. The method according to claim 1 , wherein the downlink control information message has a format selected from one of a format used for informing multiple UE devices about control settings and a format for scheduling with superpositioning.

3. The method of claim 1 , wherein the set of control parameters includes a set of fractional transmit power allocations for the UE devices.

4. The method according to claim 1 , wherein the at least one radio resource measurement report contains information relating to at least one of:

channel gain estimation,

signal to noise ratio,

signal to interference plus noise ratio,

reference signal received power measurements, and

reference signal received quality measurements.

5. The method according to claim 1 , wherein after a pre-selection of UE devices best suited for operation in a NOMA mode, such pre-selected UE devices are instructed to perform NOMA specific measurements on downlink radio resources.

6. The method according to claim 1 , wherein transmit power levels of the members of the NOMA group are adjusted among the group members.

7. The method according to claim 1 , wherein power allocation information is transmitted to the UE devices by means of a system information broadcast message.

8. The method according to claim 1 , wherein power allocation information is transmitted to the UE devices by one or more radio resource control, RC, messages.

9. The method according to claim 1 , wherein power allocation information is transmitted with the downlink control information, DCI, in a physical downlink control channel region of an LTE sub-frame.

10. The method according to claim 1 , wherein transmit power allocation is performed by a serving E-UTRAN node B, eNB.

11. The method according to claim 1 , wherein transmit power allocation is performed by an entity in the radio access network or the core network.

12. The method according to claim 1 , wherein after UE devices have been assigned to a NOMA group, NOMA specific radio resource measurements are requested from the UE devices.

13. The method according to claim 12 , wherein such measurements are to be made periodically.

14. The method according to claim 12 , wherein such measurements are to be made event triggered.

15. The method according to claim 1 , wherein a periodicity for configuring UE devices for NOMA specific resource measurements is aligned with a configuration of regular measurements for radio resource management purposes.

16. The method according to claim 1 , wherein signalling is provided providing information about a projected duration of a current fractional transmit power allocation or a time limit for such allocation.