CN110089174B - Method and apparatus for selecting resources for direct communication between wireless devices in a wireless communication system - Google Patents

Abstract

The long term evolution cellular communication system supports direct communication between mobile devices (102, 108), particularly vehicle-to-pedestrian direct communication. The vehicle configuration UE (108) monitors the configured resources in the resource pool for sidelink communications and identifies resources that may be released for use without risk of collision with existing transmissions from other UEs. The vehicle configuration UE then broadcasts information to the pedestrian configuration UE (102) to assist the UE (102) in resource selection with a lower probability of collision than the randomly selected resources. In another embodiment, a pedestrian-configured UE (102) monitors allocated resources by itself only for a limited time based on the resource pool load conditions provided to the pedestrian-configured UE by a vehicle-configured UE (108).

Description

Method and apparatus for selecting resources for direct communication between wireless devices in a wireless communication system

Technical Field

Embodiments of the present invention relate generally to wireless communication systems, and more particularly to an apparatus and method for selecting resources to enable direct communication between mobile wireless communication devices, and are particularly applicable to the selection of resources by a pedestrian user device (Pedestrian User Equipment, P-UE) on a so-called PC5 resource pool shared with a vehicular user device (Vehicle User Equipment, V-UE) or with an infrastructure user device (Infrastructure User Equipment, I-UE).

Background

Conventional wireless networks for mobile devices (UEs) rely on cellular network infrastructure to support UE communications. In these conventional networks, even for communications between a pair of UEs, the communications are managed by a plurality of network nodes. This Uplink (UL) and Downlink (DL) transmission is always between one UE and one network node (e.g. one eNB/eNodeB). As an alternative to communication between UEs through network nodes, direct communication uses direct links between UEs. The only role of the network node, if any, is to establish a direct connection and allocate resources. Release 13 of 3GPP Long-Term Evolution (LTE) considers this type of non-centralized communication, where the Term "Sidelink" is used to refer to a direct connection between UEs. The so-called PC5 interface on each UE facilitates a direct connection between a pair of UEs.

For direct communication between UEs, there are two types of resource pools, a planned allocation (Scheduling Assignment, SA) Pool, also known as a sidelink control Pool (Sidelink control Pool), and a Data Pool (Data Pool). Information is transmitted through the SA pool to indicate data transmissions in the data pool. The data pool is used for transmitting data. Each resource pool consists of a plurality of resources, or physical resource composition blocks (Physical Resource Block, PRBs) and subframes (subframes). Each data transmission is associated with an SA transmission for informing the receiving UE of the data parameters. The receiving UE needs blind decoding (decoding) to control the transmission and then decodes the data.

Each UE operates in half duplex mode, where each UE cannot receive and transmit on the same subframe. Thus, for each SA period when a UE is transmitting, the UE cannot receive the SA and data transmissions that occur on the same subframe. The term "SA period" herein refers to a period during which resources are allocated to a Cell (Cell) in which SA transmission occurs.

There are two modes of selecting resources for use by the UE performing the transmission, mode 1 and mode 2. In mode 1, the network node allocates SA and data resources. In this case, the UE sends a request to a network node through a Uu link, and the network node replies with an Grant assignment (Allocation Grant) using specific downlink control information (Downlink Control Information, DCI for short). Therefore, mode 1 is a resource allocation method that avoids Contention (content Free).

In mode 2, the UE allocates resources without any assistance from the network node. For vehicle-to-vehicle communication, the third generation partnership project (Third Generation Partnership Project, 3GPP for short) has agreed upon algorithms for resource (re) selection involving sensing operations by energy measurement or SA decoding. The assumptions of operation are:

a period, wherein the transmission period is typically from 100 milliseconds to 1000 milliseconds. For pedestrian-to-vehicle communication, whether the P-UE performs only random resource selection or sensing operation for a limited time has not been agreed. Random resource selection represents a contention-based resource allocation scheme. Therefore, a conflict in resource selection easily occurs. This can be particularly a problem in situations where there are many UEs and the data traffic is high.

Herein, V2X terminology refers to communication services based on LTE to connect vehicles, pedestrians, and infrastructure; V2V refers to communication between LTE-based vehicles; V2P refers to communication between an LTE-based communication vehicle and a device carried by a person (e.g., a pedestrian, cyclist, driver, or passenger's handheld terminal); V2I refers to communication between LTE-based vehicles and Roadside units (Roadside units). The roadside units may be implemented in enbs or static UEs.

In providing road safety, communication between P-UE and V-UE is critical to prevent potential accidents. Pedestrians who receive V2P (vehicle to pedestrian) messages may incur delays on the artificial time scale that are too slow and may further distract the person from the road. A vehicle message received P2V (pedestrian to vehicle) reacts much faster on a machine time scale delay. P2V (i.e., pedestrian UE transmission and vehicular UE reception) is prioritized over V2P (i.e., vehicular UE transmission and pedestrian UE reception). The 3GPP has identified collisions as a problem when randomly selecting resource transmissions from the pool. Thus, in V2V, 3GPP introduces a sensing mechanism to alleviate this problem, let the vehicle sense the load of a channel and decide on a least congested resource. However, this sensing approach is not a P-UE option because it can result in significant power consumption. Furthermore, in the current V2P scheme, the P-UE has consumed considerable power because it needs to receive V2P information generated every 100 milliseconds for at least those vehicles in the vicinity. On the other hand, P2V may reduce battery power consumption because the P-UE only needs to access the channel once every 1000 ms. However, the exact battery consumption depends on the "sensing" behavior of the P-UE for identifying possible resources. If the P-UE is also able to sense the channel to identify which resources are occupied by other UEs, the P-UE power consumption will increase accordingly as the sensing time increases.

It would be beneficial to provide a method for P-UE to minimize the probability of P2V and P2V communication collisions without having to perform relatively long sensing operations that would reduce battery life.

Disclosure of Invention

According to a first aspect of the present invention there is provided a resource selection method for selecting resources for direct communication between wireless communication devices over a sidelink of a wireless communication system, the method comprising monitoring, at a first wireless communication device, a plurality of resources in a pool of resources allocated for use over the sidelink during a first time interval, broadcasting broadcast information relating to the monitored resources, and selecting, at a second wireless communication device, resources from the plurality of resources allocated for the sidelink based on the received broadcast information.

In one embodiment the broadcast information includes an indication of at least one allocated resource for selection by the second wireless communication device. The resource or resources are the most likely resources to be selected.

In another embodiment, wherein the broadcast information includes an indication of a resource pool load, and the method further comprises monitoring, in the second wireless communication device, the plurality of allocated resources and selecting resources therefrom for a second time interval at a decision time interval value according to the resource pool load.

In one example, the alternative resource indication may be signaled on a physical sidelink control channel (Physical Sidelink Control Channel, PSSCH). An indication of the resource pool load may be signaled on a physical sidelink control channel (Physical Sidelink Control Channel, PSCCH). However, these indications are not limited to these two particular channels.

In one example, the broadcast information includes an indication of whether a resource pool load exceeds a predetermined threshold.

According to a second aspect of the present invention there is provided a first wireless communication device comprising a receiver for monitoring a plurality of resources in a pool of resources allocated for use on a side link of a wireless communication system during a first time interval, a signal processor for determining information about the monitored resources, and a transmitter for broadcasting the information to reception at a second wireless communication device of the wireless communication system.

According to a third aspect of the present invention there is provided a second wireless communication device comprising a receiver for receiving broadcast information from a first wireless communication device of a wireless communication system, the broadcast information relating to a plurality of resources that have been allocated to a pool of resources for use on a bypass link to be monitored by the first wireless communication device, and a signal processing circuit for selecting a resource from the plurality of resources that have been allocated based on the received broadcast information.

The signal processing circuitry is arranged to determine a value of a second time interval in dependence on the resource Chi Fuzai, and wherein the receiver is arranged to monitor the plurality of resources and to select a resource from the plurality of resources in the second time interval.

The wireless communication system may be an LTE system and the sidelink may comprise a PC5 link. The first wireless communication device may be a V-UE or an I-UE and the second wireless communication device may be a P-UE. Each UE may contain a PC5 interface.

The P-UE may receive suggestions of potentially available resources from multiple V-UEs, aggregate the received suggestions, and select one resource from the aggregated list.

The present invention helps to avoid resource collision when P-UE and V-UE share the same resource pool, while saving power consumption of the P-UE's battery by minimizing P-UE reception time (by setting a relatively small time interval for P-UE listening channel activity). Another benefit is reduced delay because the present invention allows for a shorter offset to be selected, allowing P-UE transmissions to follow the resource selection almost immediately.

In one embodiment, the V-UE detects a PC5 link for planning allocation (SA) resources for a sufficient time to allow the V-UE to learn V2X transmission behavior and periodicity. Thus, the V-UE can predict future unallocated resource allocations and provide such useful information to the P-UE over the sidelink. Alternatively, the P-UE may join the PC5 detected for a smaller period of time for V2X plan allocation (SA) resources and identify the resources to be selected. Thus, the P-UE may have a better understanding of the most likely overall view of available resources when using a small amount of resource detection time. Both V-UE and P-UE resource collisions are reduced compared to purely random resource selection.

In other embodiments, the P-UE may take into account other factors in selecting resources or setting the duration of its monitoring period. For example, a network node, e.g., an eNB, in the wireless communication system may transmit additional information for the P-UE to receive about load or resource availability. In another example, the I-UE may communicate location information to the P-UE. In another example, the P-UE may use On-Board Sensors, modules, or application inputs to affect its resource selection. For example, if the P-UE is currently indoors or in a pedestrian private area, this is the most likely interaction with the V-UE. Therefore, there is no need to listen to V2X SA resources. On the other hand, if a P-UE is detected to be dangerous due to a sudden change in speed or direction near the road, for example, the P-UE needs to establish a reliable and low-delay connection with any V-UE nearby, so an appropriate sensing period should be set.

According to a third aspect of the present invention there is provided a non-transitory computer readable medium having instructions stored thereon for execution by a processor of the method according to any one of claims 1 to 7.

The non-transitory computer readable medium includes at least one of the group consisting of a hard disk, a compact disk read-only memory (Compact Disc Read Only Memory, CD-ROM), an optical storage device, a magnetic storage device, a read-only memory, a programmable read-only memory, an erasable programmable read-only memory (Erasable Programmable Read Only Memory, EPROM), an electronically erasable programmable read-only memory, and a flash memory.

Drawings

Further details, aspects and embodiments of the invention will be described, by way of example only, with reference to the accompanying drawings. The elements of the drawings are not necessarily drawn to scale for simplicity and clarity of illustration. Like reference numerals have been included in the various figures to facilitate understanding.

Fig. 1 is a simplified block diagram of a portion of a wireless communication system operating in accordance with an example embodiment.

Fig. 2 is a simplified flow diagram of an example of a method performed by one or more V-UEs for assisting the P-UEs in selecting resources for sidelink transmission; and

fig. 3 is a simplified flow diagram of an example of a method performed by a P-UE for selecting resources for sidelink transmission.

Detailed Description

Those skilled in the art will recognize and appreciate that the specifics of the examples described are merely illustrative of some embodiments and that the teachings described herein are applicable in a variety of other contexts.

Referring now to fig. 1, a portion of an LTE cellular communication system is illustrated and designated 100, including an Evolved node B (eNB) 101 supporting an LTE Cell (Cell), in accordance with an embodiment of the present invention. Other enbs (not shown) may form part of the communication system and support other related cells. The enbs described above may be connected to a number of other conventional network components (not shown). The eNB 101 may communicate with one or more User Equipment (UEs) and may allocate resources for use by the User Equipment to communicate directly with each other. The first user device 102 is located within the coverage area of the eNB 101 and comprises a receiver 103, a transmitter 104, a global positioning system (Global Positioning System, GPS) 105 and a signal processing circuit 106, the function of which will be described below. The first user device 102 further comprises a PC5 interface 107. The first user device 102 is carried by a pedestrian, hereinafter referred to as P-UE. The second UE108 is located in a vehicle, hereinafter V-UE 108. The V-UE moves with variable speed and may move within the coverage of the eNB 101. The V-UE108 is equipped with a transmitter 109, a receiver 110, a PC5 interface 111, and a signal processor 112, the functions of which will be described below. The P-UE102 and V-UE108 may communicate directly with each other and with other similar UEs (not shown) in the vicinity over a sidelink 113.

Direct communication between two UEs, in particular in this case the P-UE102 and the UE108 via the sidelink 113 is based on two physical channels, a physical sidelink shared channel (Physical Sidelink Control Channel, PSSCH) carrying the actual transport channel data; and the carried control information enables the receiving UE to detect and decode the PSCCH of the data. The LTE communication system 100 supports V2X services, and the V-UE108 transmits V2V and V2P information with a period that depends on its road speed. Typically, the V-UE108 transmits a 300 byte of information, followed by four 190 bytes of information, over a period ranging from 100 milliseconds to 1 second, depending on the road speed. The anticollision array partnership suggests that vehicles traveling at speeds around 60 km/h should transmit every 300 milliseconds, while vehicles traveling at slower speeds of 15 km/h may transmit every 1000 milliseconds. The P-UE102 moves at walking speed to transmit P2V information typically every 1000 milliseconds. The information size is fixed at 300 bytes.

One option for resource selection on the sidelink is an automatic resource selection mode, wherein the UE is an autonomously selected resource. In this mode, before the UE can transmit information over the sidelink 113, it must select one resource from among several resources that the eNB 101 has allocated for the sidelink for this purpose. Some of the resources may have been used by other V-UEs in the vicinity. To assist in selecting resources, the V-UE108 employs a sensing-based autonomous resource selection procedure. As described above, there are two types of resource pools, a Scheduling Assignment (SA) pool and a data pool, for direct communication between UEs. Information is transmitted through a Scheduling Assignment (SA) pool to indicate data transmissions in the data pool. It will be appreciated that in some arrangements, the pools may overlap or be a single pool. The V-UE108 may perform energy measurements to detect those SA pool resources currently being used by other UEs and thus cannot be used by itself. The time period for taking these energy measurements may be relatively long, as the power consumption of the UE installed in the vehicle is not an issue. (e.g., a window size of 600 ms should be sufficient to perceive transmissions from V-UEs for periods of up to 600 ms, i.e., for vehicle speeds exceeding 28 km/h). To avoid resource collision, only those resources that are determined to be empty by the V-UE108 may be selected in the preferred case. It has also been proposed that the UE signals in the SA the predicted time of its next transmission, for example a 100 x K function (e.g. in case of 300 ms transmission k=3, and maximum k=10 to support 100 ms to 1000 ms). From these measurements, the signal processor 112 in the V-UE108 may identify one or more selectable resources and compile a list of such resources to inform the P-UE 102. In this way, the P-UE102 receives assistance from the V-UE, enabling it to select good resources, thereby reducing the number of resource conflicts that can occur if the P-UE performs random blind resource selection, and reducing battery consumption that can result if the P-UE performs its own sensing measurements for a long period of time, e.g., 600 to 1000 milliseconds. (it will be appreciated that the terms "resources" and "resources" may include a set of physical resource blocks (Physical Resource Blocks). Furthermore, the signal processor 112 in the V-UE108 learns V2X SA pool resource behavior and periodicity from sensing measurements and predicts future unallocated allocation jobs. The P-UE102 will be informed of the identity of future unallocated allocation jobs, the P-UE102 may be used to select one resource for its own use. It will be appreciated that a consensus in V2V resource allocation is that one V-UE recognizes resources to be occupied and/or conflicted by other UEs and avoids configuring conflicted resources for their transmissions to the P-UE 102.

Information from the V-UE108 to the P-UE102 identifying a potential unoccupied

These resources may thus be selected by the P-UE102 and this information is transmitted over the sidelink 113 using the PSSCH. Upon initially determining that the resource pool is loaded, the V-UE108 detects whether the pool load exceeds a common threshold for all V-UEs in the vicinity, and if so, the V-UE108 signals the P-UE102 on the PSCCH that this is true.

The notification may be issued by adding a flag bit (flag bit) in the SA. This should not substantially increase the SCI coding rate. Another implementation, i.e. V-UE, may indicate without adding any bits to the SA information (without altering its content), i.e. masking the CRC (cyclic redundancy check) for SCI decoding by masking. The SA information length will be preserved. Attached, the CRC Parity Bits (Parity Bits) are mixed with corresponding radio network temporary identities (Radio Network Temporary Identity, RNTI) and Chi Fuzai indication masks (Scramble).

An implementation of transmitting the identification of the most likely available resources from the V-UE108 to the P-UE102 via the PSSCH may involve Multiplexing (Multiplexing) and Interleaving (Interleaving) one bit stream of the proposed allocation with Transport Block (TB), the allocation being accompanied by CRC attachments and encoded in Reed-Muller or Viterbi. Advantageously, this provides timely information because it does not require MAC suspension that would add delay. The influence on the TB coding rate can be minimized by design.

In the P-UE102, upon receipt of the most likely list of available resources (compiled at the V-UE 108), the signal processing circuitry 106 in the P-UE102 may select the appropriate resource with the smallest collision opportunity. The P-UE102 may also receive similar manifests from other V-UEs in the vicinity. The signal processing circuitry 106 may consider other factors in selecting resources by considering the information in one or more manifests. For example, resources suggested by V-UEs that are closer to the P-UE102 may be weighted higher. The proximity of a particular V-UE may be determined by the P-UE102 based on RSSI (received signal strength indicator).

If the P-UE102 does not receive notification that the resource pool is loaded and therefore does not receive any suggestion of any V-UE for possible available resources, the P-UE102 may be preset to a conventional manner of randomly selecting resources if transmission is required. If a V-UE informs the P-UE102 that the resource pool is loaded (using PSCCH), the P-UE102 will aggregate all of the proposed resources (given on the PSSCH) and choose between them. Alternatively, if PSSCH does not support such information, the P-UE102 can perform its own sensing measurements (by listening to V2X transmissions) in a similar manner to the procedure performed by the V-UE108 described above, except for a shorter time to maintain as low battery consumption as possible. The sensing time duration may be selected based on an evaluation of the resource pool load. This can be inferred if the P-UE has been listening for transmissions previously. If no transmissions are detected at all, then the pool is assumed to be empty. The evaluation of the pool load may also depend on the sensed transmission density of other UEs. Alternatively, one or more V-UEs may give an indication of the pool load value from a plurality of options, and the pool load value corresponds to a recommended sensing time duration for the P-UE. If no transmission is detected, the lowest pool load is assumed.

If the GPS module 105 detects that the P-UE102 is in an indoor or pedestrian area, no interaction with V-UEs is required, and therefore no P2V information is transmitted. Thus, as long as the P-UE102 remains in such a location, it is not necessary to listen to any V2X SA transmissions and battery life may be conserved. For example, if the GPS module 105 detects a sudden change in the P-UE102 speed or movement in a busy road direction, the P-UE102 needs to connect with low latency and reliably transmit P2V information. In this case, the signal processing circuit selects a relatively long sensing time and makes a sensing measurement to identify available resources.

Reference will now be made to the flowcharts of fig. 2 and 3, which illustrate an example method for a P-UE to select resources for sidelink transmission. Fig. 2 relates to operations performed by one or more V-UEs 108, and fig. 3 relates to operations performed by one P-UE 102.

In a first method, referring to fig. 2, the V-UE monitors V2X transmissions in a resource pool at 201. If the monitoring step reveals that the resource pool load does not exceed the predetermined threshold in 202, the V-UE will inform it that the resource pool is not loaded by broadcasting a message for the P-UE102 in 203. Referring now to fig. 3, if in 301 the P-UE receives notification from the V-UE that the resource pool is not loaded, then in 302 the P-UE will attempt to randomly select resources from the resource pool.

In a second method, referring to fig. 2, when the pool load is detected to exceed the threshold in 202, a V-UE (204) sends a pool load notification to the P-UE in 204. In 301 (see fig. 3), when the P-UE receives the pool load notification, the method proceeds to 303, where the P-UE discriminates whether the PSSCH conveys a broadcast proposal for any potentially available resources. If no advice is received, the P-UE decides a monitoring interval value (monitoring interval value) according to the resource pool load, and at 305, by monitoring V2X SA transmissions in the resource pool (at the decided interval) to perform a sensing-based resource selection procedure to identify a suitable (available) resource with a lower probability of collision with other transmissions.

In a third method, referring to fig. 2, in case the resource pool load reaches above a threshold, the V-UE identifies a number of most likely available resources in the resource pool in 205. In 206, the V-UE broadcasts identification information of the most likely available resources for receipt by the P-UE. Referring now to fig. 3, in 303, the P-UE detects that the PSSCH conveys a broadcast proposal; (these suggestions of the most likely available resources are provided by several V-UEs), and in 306 resources are selected from the broadcast suggestions.

Although the above embodiments are described with reference to a V-UE providing information for the P-UE to select resources, the methods are equally applicable to I-UEs.

The signal processing functions of the various embodiments of the present invention may be implemented by computing systems or architectures known to those skilled in the relevant art. Computer systems may be used in a given application or environment, such as desktop, notebook or notebook computers, hand-held computing devices (personal digital assistants (Personal Digital Assistant, PDAs), cell phones, palm top computers, etc.), mainframes, servers, clients, or any other type of special or general purpose computing device. The computing system may include one or more processors, which may be implemented using a general-purpose or special-purpose processing engine (e.g., a microprocessor, microcontroller, or other control module).

The computing system may also include a main memory, such as random access memory (Random Access Memory, RAM) or other volatile memory, for storing information and instructions to be executed by the processor. Such main memory may also be used for storing temporary variables or other intermediate information during execution of instructions by a processor. Also, the computing system may include a Read Only Memory (ROM) or other static storage device for storing static information and instructions for the processor. The computing system may also include an information storage system, such as may include a media disk drive and a removable storage device interface. The media disk drive may include a disk drive or other mechanism that supports fixed or removable storage media, such as a hard disk drive, floppy disk drive, tape drive, optical disk drive, compact disk drive, or digital video disk (Digital Video Disc, DVD) drive read or write (R or RW) disk drive or other removable or fixed media disk drive. The storage medium may include, for example, a hard disk, floppy disk, magnetic tape, compact Disc (CD) or DVD, or other fixed or removable medium that is read by and written to by a media disk drive. The storage medium may include a computer-readable storage medium having particular computer software or data stored therein

In alternative embodiments, the information storage system may include other similar components to allow computer programs or other instructions or data to be loaded into the computing system. For example, such components may include removable storage units and interfaces such as program cartridge and cartridge interfaces, removable memory (e.g., flash memory or other removable memory modules) and memory slots, and other removable storage devices and interfaces that allow software and data to be transferred from the removable storage units to the computing system.

The computing system may also include a communication interface. Such a communication interface may be used to allow software and data to be transferred between the computing system and an external device. Examples of communication interfaces include modems, network interfaces (e.g., ethernet or other network interface controller (Network Interface Controller, NIC) cards), communication ports (e.g., universal serial bus (Universal Serial Bus, USB) ports), personal computer memory card international association (Personal Computer Memory Card International Association, PCMCIA) slots and cards, and the like. Software and data transferred via the communications interface are in the form of electronic, electromagnetic, optical or other signals capable of being received via the communications interface medium.

In this document, the terms "computer program product," "computer-readable medium," and the like may be used to generally refer to tangible media, such as memory, storage devices, or storage units. These and other forms of computer-readable media may store one or more instructions for use by a processor comprising a computer system to cause the processor to perform specified operations. Such instructions, often referred to as "computer program code" (which may be grouped in the form of computer programs or other groupings), when executed, enable the computer system to perform functions of embodiments of the present invention. Note that the code may directly cause the processor to perform specified operations, be compiled to do so, or be used in combination with other software, hardware, and firmware elements (e.g., to perform standard function libraries).

In an embodiment in which the elements are implemented using software, the software may be stored in a computer-readable medium and loaded into a computing system using, for example, a removable storage disk drive or the like. A control module (in this example, software instructions or executable computer program code) when executed in the processor of the computer system causes the processor to perform the functions of the invention as described herein.

Furthermore, the inventive concept is applicable to any circuit in a network element that performs signal processing functions. It is further contemplated that, for example, a semiconductor manufacturer may use the concepts of the present invention in the design of a stand-alone device, such as a microcontroller of a digital signal processor (Digital Signal Processor, DSP), or an Application-specific integrated circuit (ASIC) and/or any other subsystem element.

For clarity, it will be appreciated that the above description describes embodiments of the invention with reference to a single processing logic. However, the inventive concept may equally be implemented by a number of different functional units and processors to provide signal processing functionality. Thus, references to specific functional units are only to be seen as references to suitable means for providing the described functionality rather than indicative of a strict logical or physical structure or organization.

Certain aspects of the invention may be implemented in any suitable form including hardware, software, firmware or any combination of these aspects. The invention may alternatively be implemented, at least in part, as computer software running on one or more data processors and/or digital signal processors or configurable module components, such as Field programmable gate array (Field-Programmable Gate Array, FPGA) devices. Thus, the elements and components of an embodiment of the invention may be physically, functionally and logically implemented in any suitable way. Indeed the functionality may be implemented in a single unit, in a plurality of units or as part of other functional units.

Although the present invention has been described in connection with some embodiments, it is not intended to be limited to the specific form set forth herein. Rather, the scope of the invention is limited only by the appended claims. Furthermore, although a feature may appear to be related to a particular embodiment, those skilled in the art will appreciate that various features of the described embodiments may be combined in accordance with the invention. In the claims, the word "comprising" does not exclude the presence of other elements or steps.

Furthermore, although individually listed, a plurality of means, elements or method steps may be implemented by a single unit or processor. Furthermore, although individual features may be included in different claims, these elements may possibly be combined for some advantages and the inclusion in different claims does not imply that a combined feature is not feasible and/or advantageous. Furthermore, the inclusion of a feature in one claim category does not imply a limitation to this category but rather indicates that the feature is equally applicable to other claim categories as appropriate.

Furthermore, the order of the features in the claims does not imply any specific order in which the features must be worked and in particular the order of individual steps in a method claim does not imply that the steps must be worked in this order. Rather, the steps may be performed in any suitable order. Furthermore, singular references do not exclude a plurality. Thus, references to "a," "an," "the first," "the second," etc. do not exclude a plurality.

Although the present invention has been described in connection with some embodiments, it is not intended to be limited to the specific form set forth herein. Rather, the scope of the invention is limited only by the appended claims. Furthermore, although a feature may appear to be related to a particular embodiment, those skilled in the art will appreciate that various features of the described embodiments may be combined in accordance with the invention. In the claims, the terms "comprising" or "including" do not exclude the presence of other elements.

Claims (17)

1. A method of selecting resources for direct communication between wireless communication devices over a sidelink of a wireless communication system, the method comprising:

monitoring, at a first time interval, a plurality of resources in a pool of resources allocated for use on the sidelink, the first wireless communication device learning from the sensing measurements a pool resource behaviour and period of Vehicle-to-evaluation (V2X) plan allocation (Scheduling Assignment, SA) and predicting future unallocated allocation jobs to identify one or more most likely suggestions of available resources as information of monitored resources, broadcasting information about the monitored resources as broadcast information, the monitored resource information identifying one or more available resources with a lower probability of collision with other transmissions; and

at the second wireless communication device, a resource having a smallest collision opportunity is selected from a suggestion of the one or more most likely available resources of the plurality of resources that have been allocated to the sidelink based on the received broadcast information.

2. The method of claim 1, wherein the broadcast information includes an indication of at least one allocated resource for selection by the second wireless communication device.

3. The method of claim 2, wherein the wireless communication system is a Long Term Evolution (LTE) system, the sidelink comprises a PC5 link, and the indication of at least one allocated resource is transmitted using a physical sidelink shared channel and is transmitted by multiplexing and interleaving a transport block with a bit stream of each identified allocated resource.

4. The method of claim 1, wherein the broadcast information comprises an indication of a resource pool load, and the method further comprises: the second wireless communication device monitors the allocated plurality of resources and selects resources from among the plurality of resources in a second time interval based on the resource pool load to determine a value of the second time interval.

5. The method of claim 1, wherein the broadcast information includes an indication indicating whether a resource pool load of the resource pool exceeds a predetermined threshold.

6. The method of claim 4, wherein the wireless communication system is an LTE system and the sidelink comprises a PC5 link, and the broadcast information is transmitted with a physical sidelink control channel by adding a flag bit in a planned allocation (Scheduling Assignment, SA).

7. The method of claim 4, wherein the wireless communication system is an LTE system and the sidelink comprises a PC5 link, and the broadcast information is transmitted with a physical sidelink control channel through cyclic redundancy check (Cyclic Redundancy Check, CRC) screening.

8. A first wireless communications device, comprising:

a receiver;

a signal processor; and

a conveyor;

the receiver is configured to monitor a plurality of resources in a pool of resources allocated for use on a sidelink of a wireless communication system during a first time interval;

the signal processor is used for judging information about monitored resources, learning Vehicle-to-evaluation (V2X) plan allocation (Scheduling Assignment, SA) pool resource behaviors and periods from sensing measurement, and predicting future unallocated allocation jobs to identify one or more suggestions of most likely available resources as the information of the monitored resources, broadcasting the information about the monitored resources as broadcast information, wherein the information of the monitored resources identifies one or more available resources with low probability of collision with other transmission;

the transmitter is configured to broadcast information of the monitored resource for receipt at a second wireless communication device of the wireless communication system.

9. The first wireless communication device of claim 8, comprising a V2X capable vehicular user device (Vehicle User Equipment, V-UE).

10. The first wireless communication device of claim 8, comprising an infrastructure user equipment (Infrastructure User Equipment, I-UE) capable of V2X transmission and reception.

11. A second wireless communication device comprising:

a receiver; and

a signal processing circuit;

the receiver is configured to receive broadcast information from a first wireless communication device of a wireless communication system, the broadcast information regarding a plurality of resources that have been allocated to a pool of resources used on a bypass link for monitoring by the first wireless communication device, and to identify one or more suggestions of most likely available resources as information of the monitored resources; and

the signal processing circuitry is to select a resource having a smallest collision opportunity from a suggestion of the one or more most likely available resources of the plurality of resources that have been allocated based on the received broadcast information.

12. The second wireless communications device of claim 11, wherein the received broadcast information includes a notification of a resource pool load, wherein the signal processing circuitry is configured to determine a value for a second time interval based on the resource Chi Fuzai, and wherein the receiver is configured to monitor the plurality of resources and select a resource from the plurality of resources during the second time interval.

13. The second wireless communications apparatus of claim 12, wherein the signal processing circuit is configured to adjust the value of the second time interval based upon a plurality of external factors.

14. The second wireless communications device of claim 13, wherein the external factors include at least one of:

a location of the second wireless communication device; or (b)

The broadcast information is received from other wireless communication devices, and resources suggested by other wireless communication devices closer to the second wireless communication device may be weighted higher, the proximity of the other wireless communication devices to the second wireless communication device being determined by the second wireless communication device based on a Received Signal Strength Indication (RSSI).

15. The second wireless communication device according to any of claims 11 to 14, comprising a pedestrian user device (Pedestrian User Equipment, P-UE) capable of V2X transmission and reception.

16. A non-transitory computer readable medium comprising instructions stored thereon for execution by a processor of the method of any of claims 1 to 7.

17. The non-transitory computer-readable medium of claim 16, comprising at least one of the group consisting of: hard disk, compact disk read-only memory (Compact Disc Read Only Memory, CD-ROM), optical storage devices, magnetic storage devices, read-only memory, programmable read-only memory, erasable programmable read-only memory (Erasable Programmable Read Only Memory, EPROM), electronically erasable programmable read-only memory, and flash memory.

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