System and method for hybrid automatic repeat request timing for device-to-device communication overlaid on a cellular network
An embodiment of a system for operating a communications controller for a group of user equipments engaged in a DMC link in a wireless communications system is provided. The communications controller is configured to allocate a set of subframes in one periodic group of subframes to the group of UEs for the DMC link, signal the set of allocated subframes to the group of UEs, and transmit parameters related to a group of HARQ processes of the DMC link. In an embodiment, the communication controller uses HARQ processes for cellular UE transmission that are determined independently from HARQ processes of the group of HARQ processes for the DMC link, and the parameters are configured to enable the group of UEs to manage the group of HARQ processes for the DMC link.
1. A method of communicating between a group of user equipments (“UEs”) on a direct mobile communication (DMC) link, the method comprising:
a first UE of the group of UEs determining DMC resources for transmission, wherein the group of UEs are assigned a group ID;
the first UE scrambling data using a scrambling sequence defined by the group ID to generate scrambled data; and
the first UE transmitting the scrambled data using one or more subframes allocated to the first UE in the DMC resources.
2. The method of claim 1 , further comprising:
transmitting, by the first UE to the group of UEs, a scheduling grant identified by the group ID to indicate a frequency resource allocation, modulation and coding scheme (MCS).
3. The method of claim 1 , further comprising:
transmitting, by the first UE to the group of UEs, a scheduling grant identified by the group ID to indicate a frequency resource allocation, modulation and coding scheme (MCS), with the scheduling grant being valid in following multiple subframes allocated to the group of UEs.
4. The method of claim 1 , further comprising the first UE transmitting a demodulation reference signal (DMRS) sequence with the scrambled data, with the DMRS sequence being defined by the group ID.
5. The method of claim 4 , further comprising:
transmitting, by the first UE to the group of UEs, a scheduling grant identified by the group ID to indicate a frequency resource allocation, modulation and coding scheme (MCS).
6. The method of claim 4 , further comprising:
transmitting, by the first UE to the group of UEs, a scheduling grant identified by the group ID to indicate a frequency resource allocation, modulation and coding scheme (MCS), with the scheduling grant being valid in following multiple subframes allocated to the group of UEs.
7. The method of claim 1 , further comprising a preliminary step of the first UE receiving a DMC resource allocation.
8. The method of claim 1 , wherein the DMC comprises device-centric DMC.
9. The method of claim 1 , wherein the DMC comprises network-centric DMC.
10. The method of claim 1 , wherein the group of UEs comprise single-link or multi-link DMC.
11. A user equipment (UE), comprising:
a transceiver; and
a processor unit coupled to the transceiver, with the processor unit, in conjunction with the transceiver, configured to cause the UE to:
determine DMC resources for transmission, with the UE being a member of a group of UEs configured for a direct mobile communication (DMC) link, wherein the group of UEs are assigned a group ID;
scramble data using a scrambling sequence defined by the group ID to generate scrambled data; and
transmit the scrambled data using one or more subframes allocated to the UE in the DMC resources.
12. The UE of claim 11 , further comprising the UE transmitting a demodulation reference signal (DMRS) sequence with the scrambled data, with the DMRS sequence being defined by the group ID.
13. The UE of claim 11 , further comprising transmitting, by the UE to the group of UEs, a scheduling grant identified by the group ID to indicate a frequency resource allocation, modulation and coding scheme (MCS).
14. The UE of claim 13 , further comprising transmitting, by the UE to the group of UEs, a scheduling grant identified by the group ID to indicate a frequency resource allocation, modulation and coding scheme (MCS), with the scheduling grant being valid in following multiple subframes allocated to the group of UEs.
15. The UE of claim 11 , further comprising a preliminary step of the UE receiving a DMC resource allocation.
16. The UE of claim 11 , wherein the DMC comprises device-centric DMC.
17. The UE of claim 11 , wherein the DMC comprises network-centric DMC.
18. The UE of claim 11 , wherein the group of UEs comprise single-link or multi-link DMC.