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, the group of UEs having a group ID;
the first UE scrambling data with a scrambling sequence defined by the group ID to generate scrambled data; and
the first UE transmitting the scrambled data using at least one subframe 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 and a 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 and a modulation and coding scheme (MCS), with the scheduling grant being valid in subsequent 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, 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 and a 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 and a modulation and coding scheme (MCS), the scheduling grant being valid in subsequent 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 comprises single-link DMC.
11. The method of claim 1 , wherein the group of UEs comprises multi-link DMC.
12. A first user equipment (UE), the first UE being a member of a group of UEs configured for a direct mobile communication (DMC) link, the first 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 first UE to:
determine DMC resources for transmission, the group of UEs having a group ID;
scramble data with a scrambling sequence defined by the group ID to generate scrambled data; and
transmit the scrambled data using at least one subframe allocated to the first UE in the DMC resources.
13. The first UE of claim 12 , further comprising the processor unit, in conjunction with the transceiver, configured to cause the first UE to transmit, to the group of UEs, a scheduling grant identified by the group ID to indicate a frequency resource allocation and a modulation and coding scheme (MCS).
14. The first UE of claim 12 , further comprising the processor unit, in conjunction with the transceiver, configured to cause the first UE to transmit, 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 subsequent multiple subframes allocated to the group of UEs.
15. The first UE of claim 12 , further comprising the processor unit, in conjunction with the transceiver, configured to cause the first UE to transmit a demodulation reference signal (DMRS) sequence with the scrambled data, the DMRS sequence being defined by the group ID.
16. The first UE of claim 15 , further comprising the processor unit, in conjunction with the transceiver, configured to cause the first UE to transmit, to the group of UEs, a scheduling grant identified by the group ID to indicate a frequency resource allocation, modulation and coding scheme (MCS).
17. The first UE of claim 15 , further comprising the processor unit, in conjunction with the transceiver, configured to cause the first UE to transmit, to the group of UEs, a scheduling grant identified by the group ID to indicate a frequency resource allocation modulation and coding scheme (MCS), the scheduling grant being valid in subsequent multiple subframes allocated to the group of UEs.
18. The first UE of claim 12 , further comprising the processor unit, in conjunction with the transceiver, configured to cause the first UE to preliminarily receive a DMC resource allocation.
19. The first UE of claim 12 , wherein the DMC comprises device-centric DMC.
20. The first UE of claim 12 , wherein the DMC comprises network-centric DMC.
21. The first UE of claim 12 , wherein the group of UEs comprises single-link DMC.
22. The first UE of claim 12 , wherein the group of UEs comprises multi-link DMC.