User equipment and method for distributed channel access for D2D communications

Patent metadata

Field	Value
Publication number	US-9345046-B2
Application number	US-201314124217-A
Country	US
Kind code	B2
Filing date	Nov 6, 2013
Priority date	Mar 29, 2013
Publication date	May 17, 2016
Grant date	May 17, 2016

Abstract

Embodiments of a system and method for distributed channel access for device-to-device (D2D) communication in a wireless network are generally described herein. User equipment (UE) may transmit a connection identifier (CID) code at a beginning of a contention window to request channel access for a D2D transmission to a receiving device. Links for D2D transmissions from a transmitting device to a receiving device are identified by a CID that is mapped to a CID code. The UE may receive a bandwidth grant from the receiving device during the contention window, along with bandwidth grants for other CIDs, in an order based on a priority level of the CID. The UE may transmit data after reception of the bandwidth grants in time-frequency resources indicated in an associated one of the bandwidth grants. In some embodiments, spatial-reuse and variable resource size allocation are supported.

First claim

What is claimed is:

1. User Equipment (UE) arranged to perform device-to-device (D2D) distributed channel access in a 3GPP-LTE network, the UE having physical-layer (PHY) circuitry and media-access control (MAC) layer circuitry arranged to:
transmit a connection identifier (CID) code at a beginning of a contention window to request channel access for a D2D transmission to a receiving device, wherein links for D2D transmissions from a transmitting device to a receiving device are identified by a CID and each CID is mapped to a CID code, wherein CID codes are configured to be transmitted concurrently at the beginning of the contention window by transmitting devices requesting an allocation of channel resources for a D2D transmission;
receive a bandwidth grant from the receiving device, the bandwidth grant being transmitted by the receiving device in response to receipt of a CID code associated with the receiving device, the bandwidth grant being received during the contention window, along with bandwidth grants, transmitted by other receiving devices for other CIDs, the bandwidth grants being received sequentially during the contention window in an order based on a priority level of the CID, the priority level used by receiving devices to allocate bandwidth on a shared data channel to transmitting devices; and
transmit data after reception of the bandwidth grants in time-frequency resources of the shared data channel indicated in an associated one of the bandwidth grants.

2. User Equipment (UE) arranged to perform device-to-device (D2D) distributed channel access in a 3GPP-LTE network, the UE having physical-layer (PHY) circuitry and media-access control (MAC) layer circuitry arranged to:
transmit a connection identifier (CID) code at a beginning of a contention window to request channel access for a D2D transmission to a receiving device, wherein links for D2D transmissions from a transmitting device to a receiving device are identified by CID and each CID is mapped to a CID code;
receive a bandwidth grant from the receiving device, the bandwidth grant being transmitted by the received device in response to receipt of a CID code associated with the receiving device, the bandwidth grant being transmitted during the contention window, along with bandwidth grants for other CIDs, in an order based on a priority level of the CID; and
transmit data after reception of the bandwidth grants in time-frequency resources indicated in an associated one of the bandwidth grants, wherein when acting as a receiving device, the UE is further arranged to:
identify other CID codes received at the beginning of the contention window;
sort the received GID codes based on the priority level to determine when to transmit a bandwidth grant; and
wait for transmission of any other bandwidth grants associated with e priority CIDs before transmitting the bandwidth grant.

3. The UE of claim 2 wherein the UE, when acting as a transmitting device, is arranged to transmit the CID code at a predetermined power level at the beginning of the contention window to request channel access, the predetermined power level determined to allow the CID code to be detected by other devices in addition to the receiving device.

4. The LE of claim 2 wherein the CID code is transmitted concurrently with CID codes of other transmitting devices that are also requesting channel access.

5. The UE of claim 2 wherein the CID code is transmitted on different time-frequency resources than CID codes transmitted by other transmitting devices that are also requesting channel access.

6. The UE of claim 2 wherein the CID codes 204 comprise pseudo-orthogonal sequences, and
wherein the transmitting device is arranged to transmit a CID code on the same time-frequency resources as CID codes that are transmitted by other transmitting devices that are also requesting channel access.

7. The UE of claim 2 wherein when acting as a receiving device, the UE is arranged to:
monitor bandwidth grants transmitted from other receiving devices having higher priority CIDs to determine remaining channel resources for allocation to an associated transmitting device;
grant bandwidth to the transmitting device when sufficient channel resources remain; and
refrain from granting bandwidth to the transmitting device when insufficient channel resources remain.

8. The UE of claim 7 wherein when acting as a receiving device having a highest priority CID, allocate channel resources prior to allocation of channel resources by other receiving devices, and
wherein when acting as a receiving device and when associated with a lower priority CID, the UE is arranged to refrain from transmitting a bandwidth grant when insufficient channel resources are available after allocation of channel resources by receiving devices with higher priority CIDs.

9. The UE of claim 8 wherein when acting as a receiving device, the UE is arranged to determine a recommended transmission power level for transmission of data based, at least in part, on signal strengths of the CID codes received from one or more transmitting devices, and
wherein the receiving device is to provide the recommended transmission power level to the associated transmitting device in a transmitted bandwidth grant.

10. The HE of claim 9 wherein when acting as a receiving device, the UE is arranged to include bandwidth allocation parameters including at least one of a starting point or offset value, a resource allocation size and the recommended transmission power level in a transmitted bandwidth grant, and
when spatial-reuse pairing is performed, a CID of a spatial-reuse pair and optionally bandwidth allocation parameters for the spatial-reuse pair are piggybacked in the transmitted bandwidth grant.

11. The UE of claim 1 wherein when acting as a transmitting device, the UE is arranged to:
enter a sleep/low-power state after the contention window;
wake-up to transmit data to an associated receiving device during channel resources indicated in a bandwidth grant; and
return to the sleep/low-power state during data transmissions of other transmitting devices.

12. The UE of claim 1 , wherein when the UE is configured for spatial-reuse and is acting as a receiving device, the UE is arranged to determine a recommended transmission power level for a spatial-reuse data transmission by an associated transmitting device,
wherein the spatial-reuse data transmission is transmitted concurrently with data of a higher priority CID on non-orthogonal time-frequency resources, and
wherein the recommend transmission power level for the spatial-reuse transmission is determined based on an interference estimate to help assure a reliable reception of the data by a higher priority receiving device of the spatial-reuse pair.

13. The UE of claim 12 wherein determining the recommended transmission power level for the spatial-reuse data transmission comprises:
estimating a path loss between the transmitting device and the receiving device of the higher priority CID based on the CID code and the bandwidth grant transmitted by the devices having the higher-priority CID, and
wherein the recommended transmission power level for the spatial-reuse data transmission is determined based on the estimated path loss and an interference threshold of the receiving device having the higher-priority CID.

14. The UE of claim 12 wherein when the UE is configured for spatial-reuse and is acting as a receiving device, the receiving device is arranged to:
select a pair of UEs having a lower priority CID as a spatial-reuse pair based on potential interference; and
provide the CID of the selected

Assignees

• Intel Ip Corp

Inventors

• Li Honggang
• Li Qinghua
• Khoryaev Alexey
• Zhu Yuan
• Fwu Jong-Kae

Classifications

• H04W74/08 Primary

  Non-scheduled access, e.g. ALOHA (hybrid access H04W74/02) · CPC title

• H04W76/11

  Allocation or use of connection identifiers · CPC title

• H04W76/14

  Direct-mode setup · CPC title

• H04W72/56

  based on priority criteria · CPC title

• H04W72/10

  Electricity · mapped topic