WO2020253939A1

WO2020253939A1 - Facilitated local context sharing in road environment

Info

Publication number: WO2020253939A1
Application number: PCT/EP2019/065892
Authority: WO
Inventors: Silvio MANDELLI; Marouan MIZMIZI; Jafar MOHAMMADI; Yejian Chen
Original assignee: Nokia Technologies Oy
Priority date: 2019-06-17
Filing date: 2019-06-17
Publication date: 2020-12-24

Abstract

An apparatus is provided which comprises, in a vehicle,at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform:receiving configuration information for a non-orthogonal multiple access channel including resources to be used for the non-orthogonal multiple access channel, detecting an environment of the vehicle, and transmitting multicast transmission messages including information about the detected environment on the assigned resources over the non-orthogonal multiple access channel according to the received configuration information, and/or receiving multicast reception messages on the non-orthogonal multiple access channel according to the received configuration information.

Description

Facilitated Local Context Sharing in Road Environment

Field of the Invention

The present invention relates to an apparatus, a method and a computer program product by which local context sharing in road environment can be facilitated . Related background Art

The following meanings for the abbreviations used in this specification apply:

AWGN : Additive white Gaussian noise

BER: Bit error rate

BS: Base Station;

CD-NOMA: Code Domain NOMA;

DSRC: Direct Short-Range Communication;

C-V2X: Cellular-V2X;

ESE: Elementary Signal Estimator

GA: Gaussian Approximation

gNB: Next Generation NodeB;

IDMA: Interleaving Division Multiple Access;

MMSE: Minimum Mean Square Error

NOMA: Non-Orthogonal Multiple Access;

NOMA-MCD: NOMA Mixed Centralized/Distributed;

OMA: Orthogonal Multiple Access;

PD-NOMA: Power Domain NOMA;

PDF: Probability Density Function

PECRA: Perception Enrichment Channel for Road Application;

PIC: Parallel Interference Cancellation

RB: Resource Block;

REP: Repetition coding UE: User Equipment

V2V: Vehicle-to-Vehicle;

V2X: Vehicles-to- Everything;

V2I : Vehicle-to-Infrastructure;

VRU : Vulnerable Road Users;

Example embodiments, although not limited to this, relate to Vehicles-to- Everything (V2X) communications. In the context of V2X communications, safety is gaining more attention both from academic and industry viewpoints. Cooperative sensor sharing is a key application to enhance road safety both for vehicles and Vulnerable Road Users (VRU) such as pedestrian, cyclist etc.

Such applications have stringent requirements in terms of communication, i.e. low latency, ultra-reliability, and high robustness against traffic congestion due to the increase of connected devices.

Future cars are equipped with multiple sensors, for example cameras, RADAR, LIDAR to detect the surrounding objects. The outputs of all these sensors form the so called "perception layer" of the car, based on which the collision avoidance system takes decisions.

Due to obstacles, e.g . buildings, hidden objects may not be detected by the car sensors. To solve this problem, many applications has been proposed, among them, cooperative perception sharing is a promising solution, as described, for example, in A. Rauch, F. Klanner, R. Rasshofer and K. Dietmayer, "Car2X-based perception in a high-level fusion architecture for cooperative perception systems," 2012 IEEE Intelligent Vehicles Symposium, Alcala de Henares, 2012, pp. 270-275.

Thus, example embodiments are related to supporting cars in sharing some information about their perception layer, which is defined as that what the vehicle knows about its environment. Solving this problem enables vehicles to react/take decisions based not only on what they can perceive, but also on what others perceive.

The performance of such application depends strongly on the communication protocol. On one hand, it cannot be relied merely on the infrastructure. On the other hand, V2V communication needs regulations, such as scheduling, hand-shaking, resource allocation, etc.

Thus, there is a need for improving communication for sharing information concerning the perception layer between vehicles.

Summary of the Invention

Example embodiments of the present invention address this situation and aim to provide a novel communication strategy that guarantees a reliable and low latency sharing of information among vehicles.

According to a first aspect, an apparatus is provided which comprises, in a vehicle, at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform : receiving configuration information for a non-orthogonal multiple access channel including resources to be used for the non-orthogonal multiple access channel, detecting an environment of the vehicle, and transmitting multicast transmission messages including information about the detected environment on the assigned resources over the non-orthogonal multiple access channel according to the received configuration information, and/or receiving multicast reception messages on the non-orthogonal multiple access channel according to the received configuration information.

According to a second aspect, a method is provided which comprises: receiving, in a vehicle, configuration information for a non-orthogonal multiple access channel including resources to be used for the non-orthogonal multiple access channel,

detecting an environment of the vehicle, and

transmitting multicast transmission messages including information about the detected environment on the assigned resources over the non- orthogonal multiple access channel according to the received configuration information, and/or receiving multicast reception messages on the non- orthogonal multiple access channel according to the received configuration information.

The first and second aspects may be modified as follows:

The apparatus or vehicle may transmit the multicast transmission messages to one or more other vehicles, and/or receive the multicast reception messages from one or more other vehicles, wherein the multicast reception messages comprise information about a detected environment or the one or more other vehicle.

The received configuration information may comprise at least one of the following : information concerning resources to be used for transmitting multicast transmission messages, information concerning resources to be used for receiving multicast reception messages, information for coding to be applied for the multicast transmission message, information for decoding multicast reception messages, a maximum transmit power to be applied for transmitting the multicast transmission messages, and an assigned time transmission timing.

The apparatus or vehicle may transmit the multicast transmission message on a resource, which is assigned to the apparatus or vehicle by the received configuration information, or may transmit the multicast transmission message on a different resource not assigned to the apparatus or vehicle when a certain condition is fulfilled. The apparatus or vehicle may include information from one or more received multicast reception messages into the multicast transmission message to be transmitted.

The apparatus or vehicle may apply interleaving division multiple access (IDMA) on the non-orthogonal multiple access (NOMA) channel for transmitting the multicast transmission messages and/or receiving the multicast reception messages.

The apparatus or vehicle may apply the interleaving division multiple access for transmitting data by applying user-specific interleaving to raw data, and applying user-specific repetition after the interleaving.

The apparatus or vehicle may apply the interleaving division multiple access for receiving data by applying linear a pre-filtering algorithm.

A seed may be assigned to the apparatus, based on which the interleaving division multiple access is applied.

The seed may be included in the received configuration information.

The apparatus or vehicle may receive information concerning neighbor objects, and may provide a neighbor list based on the received information concerning neighbor objects.

The apparatus or vehicle may authenticate with a network control element for obtaining the configuration information for the non-orthogonal multiple access channel from the network control element.

The apparatus or vehicle may transmit transmitting an estimated or detected location of the vehicle to the network control element. The apparatus or vehicle may set a transmit power for transmitting multicast transmission messages based on the speed of the vehicle.

A first message format of the multicast transmission messages and/or the multicast reception messages comprise information about at least one object, wherein for each object at least one of the following parameters are provided : an object identifier;

position of the object;

dimensions of the object;

speed of the object;

heading of the object;

confidence concerning the detection of the object;

information that indicates whether the object was detected by the vehicle or it was merged from other multicast reception messages;

seed information comprising the seed of the vehicle transmitting the message; and/or

new seed information comprising a changed seed of an object; and a second message format of the multicast transmission messages and/or the multicast reception messages comprise information about a detected collision, wherein at least one of the following parameters are provided :

collision position;

collision time;

confidence; and/or

suggested action.

According to a third aspect, an apparatus is provided which comprises at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform : obtaining information concerning vehicles in a predetermined area, each vehicle capable of detecting an environment of the vehicle, preparing configuration information for a non-orthogonal multiple access channel including resources to be used by the vehicles for exchanging multicast messages including information about the detected environment between the vehicles, and transmitting the configuration information to each vehicle.

According to a fourth aspect, a method is provided which comprises:

obtaining, in a network control element, information concerning vehicles in a predetermined area, each vehicle capable of detecting an environment of the vehicle,

preparing configuration information for a non-orthogonal multiple access channel including resources to be used by the vehicles for exchanging multicast messages including information about the detected environment between the vehicles, and

transmitting the configuration information to each vehicle.

The third and fourth aspects may be modified as follows:

The configuration information comprises at least one of the following : information concerning resources to be used for transmitting and/or receiving multicast messages, information for coding and/or decoding to be applied for the multicast messages, a maximum transmit power to be applied for transmitting the multicast messages, and a suggested time transmission timing.

The apparatus or the network control element may set the maximum transmit power for transmitting multicast transmission messages based on the speed of the vehicle.

The apparatus or the network control element may authenticate a vehicle for providing the configuration information for the non-orthogonal multiple access channel.

The apparatus or the network control element may transmit the configuration information for each vehicle to all authenticated vehicles. The apparatus or the network control element may prepare the configuration information based on the number of the vehicles and capabilities of the authenticated vehicles.

The apparatus or the network control element may obtain a location of a vehicle, and prepare the configuration information for the vehicle also based on the locations of the vehicle.

The apparatus or the network control element may assign a seed to be used for interleaving division multiple access on the non-orthogonal multiple access channel for each vehicle and include the seed in the configuration information.

The apparatus or the network control element may transmit the configuration information to the vehicles via at least one base station.

According to a fifth aspect, an apparatus is provided which comprises at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform : receiving, from a network control element, configuration information for a non-orthogonal multiple access channel including resources to be used by vehicles for exchanging multicast messages including information about the detected environment between the vehicles, and transmitting the received configuration information to each vehicle.

According to a sixth aspect, a method is provided which comprises:

receiving, in a base station from a network control element, configuration information for a non-orthogonal multiple access channel including resources to be used by vehicles for exchanging multicast messages including information about the detected environment between the vehicles, and transmitting the received configuration information to each vehicle.

The fifth and sixth aspects may be modified as follows:

The apparatus or the base station may estimate or detect a location of the vehicle, and transmit the estimated or detected location of the vehicle to the network control element.

According to a seventh aspect of the present invention a computer program product is provided which comprises code means for performing a method according to any one of the second and fourth aspects and/or their modifications when run on a processing means or module. The computer program product may be embodied on a computer-readable medium, and/or the computer program product may be directly loadable into the internal memory of the computer and/or transmittable via a network by means of at least one of upload, download and push procedures.

According to an eighth aspect an apparatus is provided which comprises means for receiving configuration information for a non-orthogonal multiple access channel including resources to be used for the non-orthogonal multiple access channel, means for detecting an environment of the vehicle, and means for transmitting multicast transmission messages including information about the detected environment on the assigned resources over the non-orthogonal multiple access channel according to the received configuration information, and/or receiving multicast reception messages on the non-orthogonal multiple access channel according to the received configuration information.

According to a ninth aspect an apparatus is provided which comprises means for obtaining information concerning vehicles in a predetermined area, each vehicle capable of detecting an environment of the vehicle, means for preparing configuration information for a non-orthogonal multiple access channel including resources to be used by the vehicles for exchanging multicast messages including information about the detected environment between the vehicles, and means for transmitting the configuration information to each vehicle.

According to a tenth aspect an apparatus is provided which comprises means for receiving, from a network control element, configuration information for a non-orthogonal multiple access channel including resources to be used by vehicles for exchanging multicast messages including information about the detected environment between the vehicles, and transmitting the received configuration information to each vehicle.

The eighth to tenth aspects may be modified similar as the first, third and fifth aspects.

Brief Description of the Drawings

These and other objects, features, details and advantages will become more fully apparent from the following detailed description of example embodiments of the present invention which is to be taken in conjunction with the appended drawings, in which :

Fig. 1A shows a UE (vehicle) 1 according to an example embodiment,

Fig. IB shows a LMF 2 according to an example embodiment,

Fig. 1C shows an eNG 3 according to an example embodiment,

Fig. 2A shows a procedure carried out by the UE 1 according to an example embodiment,

Fig. 2B shows a procedure carried out by the LMF 2 according to an example embodiment, Fig. 2C shows a procedure carried out by the gNB 3 according to an example embodiment,

Fig. 3 shows an example of interleaving as applied according to an example embodiment,

Fig. 4 shows an example of a PECRA scenario according to an example embodiment,

Fig. 5 shows an example of a PECRA message flow according to an example embodiment,

Fig. 6 illustrates a summary of perception layer sharing of the NOMA channel according to an example embodiment,

Fig. 7 shows transmitters of traditional IDMA and V2V IDMA, and Fig. 8 shows V2V IDMA transmission enabling MMSE prefiltering.

Detailed Description of example embodiments

In the following, description will be made to example embodiments of the present invention. It is to be understood, however, that the description is given by way of example only, and that the described example embodiments are by no means to be understood as limiting the present invention thereto.

Before describing example embodiments in detail, the problem underlying the present application is described in some more detail.

As mentioned above, according to example embodiments it is aimed to support cars in sharing some information about their "perception layer", defined as the what the vehicle knows about its environment. Solving this problem enables vehicles to react/take decisions based not only on what they can perceive, but also on what others perceive.

The performance of such application depends strongly on the communication protocol. On one hand, it cannot be relied rely merely on the infrastructure. On the other hand, V2V communication needs regulations, such as scheduling, hand-shaking, resource allocation, etc. According to example embodiments, a novel communication strategy is proposed that guarantees the reliable and low latency sharing of information among vehicles.

There are two main standardized protocols for V2X communication, i.e. Direct Short-Range Communication (DSRC) and Cellular-V2X (C-V2X). The former allows Vehicle-to-Vehicle (V2V) communication and is based on WLAN technology, which is not suitable for safety related applications. The latter, designed for V2X communication, outperforms DSRC in terms of delays and spectral efficiency.

Example embodiments of the present invention aims to enable Perception Layer Enrichment via Sharing (PLES) by different vehicles users in wireless networks, with the base station acting as a "facilitator", allowing the system to reliably work even when connectivity from vehicles to base stations cannot be guaranteed with sufficient confidence.

This will be a new application supported by radio standards, allowing future networks to finally solve the problem of road safety in un-conventional way for current wireless networks. Some example embodiments enable a local multicast message, that is reliable for its users, and without too much complexity/overhead to support many active entities.

In the following, a general overview of some example embodiments is described by referring to Figs. 1A, IB, 1C, 2A, 2B and 2C.

In particular, Fig. 1A shows an UE 1 as an example for a first apparatus according to the present example embodiment. In particular, the UE may be located in a vehicle. However, the invention is not limited to an UE, but can be any kind of terminal device. Fig. 2A illustrates a process carried out by the UE 1.

The UE 1 comprises at least one processor 11, at least one memory 12 including computer program code. The at least one processor 11, with the at least one memory 12 and the computer program code, is configured to cause the apparatus to perform: receiving configuration information for a non- orthogonal multiple access (NOMA) channel including resources to be used for the non-orthogonal multiple access channel (Sll in Fig. 2A), detecting an environment of the vehicle (S12 in Fig. 2A), and transmitting multicast transmission messages (as examples for PLES messages) including information about the detected environment (as an example for the perception layer) on the assigned resources over the non-orthogonal multiple access channel according to the received configuration information, and/or receiving multicast reception messages (as examples for PLES messages) on the non-orthogonal multiple access channel according to the received configuration information (S13 in Fig. 2A).

Fig. IB shows an LMF 2 as an example for a second apparatus according to the present example embodiment. However, the invention is not limited to an LMF, but can be any kind of network control element. Fig. 2B illustrates a process carried out by the LMF 2.

The LMF 2 comprises at least one processor 21 and at least one memory 22 including computer program code. The at least one processor 21, with the at least one memory 22 and the computer program code, is configured to cause the apparatus to perform : obtaining information concerning vehicles in a predetermined area, each vehicle being capable of detecting an environment of the vehicle (S21 in Fig. 2B), preparing configuration information for a non- orthogonal multiple access (NOMA) channel including resources to be used by the vehicles for exchanging multicast messages (as examples for PLES messages) including information about the detected environment between the vehicles (S22 in Fig. 2B), transmitting the configuration information to each vehicle.

Fig. 1C shows a gNB 3 as an example for a third apparatus according to the present example embodiment. However, the invention is not limited to a gNB, but can be any kind of network device, such as a base station, providing a radio connection to an UE (e.g., the UE 1 (vehicle) shown in Fig. 1A). Fig. 2C illustrates a process carried out by the LMF 2.

The gNB 3 comprises at least one processor 31 and at least one memory 32 including computer program code. The at least one processor 31, with the at least one memory 32 and the computer program code, is configured to cause the apparatus to perform : receiving, from a network control element (e.g. LMF 2 shown in Fig. IB), configuration information for a non-orthogonal multiple access (NOMA) channel including resources to be used by vehicles for exchanging multicast messages including information about the detected environment between the vehicles (S32 in Fig. 2C), and transmitting the received configuration information to each vehicle (S32 in Fig. 2C).

It is noted that in a system, the LMF 2 and a plurality of gNBs 3 may be provided, and also a plurality of vehicles (UE 1) may be provided.

The UE 1 may further comprise an I/O unit 13, which is capable of transmitting to and receiving from the gNB 3 and/or other vehicles via a radio network. The LMF 2 may further comprise an I/O unit 23, which is cable of transmitting to and receiving from the gNB 3, for example. Likewise, the gNB 3 may further comprise an I/O unit 33, which is capable of transmitting to and receiving from the UE 1 via the radio network and the LMF 2.

Thus, according to example embodiments, a communication strategy is provided which uses a NOMA channel, which allows vehicles to directly exchange information concerning their environment (perception layer). Hence, reliable and low latency sharing of the information among the vehicles is possible.

In the following, some example embodiments are described in more detail.

Some of the example embodiments focus on 3gpp terminology, but the concepts according to the example embodiments could be applied to any wireless standard. Two main parts are discussed in the following :

1. How the PHY/MAC aspects of this "Perception Enrichment Channel for Road Application" (PECRA) are designed.

2. How different vehicles share PLES messages/information about the environment.

In the following, an overview over the features of an example embodiment is given :

In contrast to literature/prior art, a system is proposed to enrich perception layer (performing collaborative road sensing) exploiting a dedicated NOMA Channel with very low power from every vehicle over the resources assigned to PECRA, where the gNB only acts as a facilitator without the requirement of continuous NOMA scheduling and supervision by the gNB (as in prior art). This allows information to be propagated from one vehicle to its neighbor ones (and only those), reducing overall data transmission from/to the gNB, see Fig. 4 for an example.

PECRA will be managed by a Facilitator/Controller, for example residing in the Location Management Function (LMF), such as the LMF shown in Fig. IB. The LMF manages a multi base station area, allowing to smoothly handle handovers and to control all PECRA features, that will be then shared with vehicles through each serving gNB. According to the present example embodiment, IDMA technique is applied for the NOMA channel. However, any other NOMA scheme can be used.

The LMF (as an example for a controller managing PECRA) works with roughly known vehicle positions (for example about 10-20 meters, however, even few tenth of meters are acceptable), estimated by LMF or communicated by proper signaling by the vehicle itself. It needs neither updated and precise position nor speed to manage PECRA, unlike previous solutions known by the inventors.

Time-Frequency resources will be reserved to PECRA based on current system demands (number of vehicles and their capabilities) and managed by the LMF. They can be statically assigned in the multi base station area, or in each cell different allocations can be made.

An IDMA seed, maximum transmit power, and a suggested time transmission period(/instant) will be assigned by the LMF to each vehicle, together with the PECRA allocated time-frequency resources. Spreading code/seed of neighbor vehicles are communicated too. Since the transmission is intended only for neighbor vehicles, low powers can be used, reducing latency, interference and re-use factor.

The actual transmit power may be set based on the vehicle speed. That is, the LMF may assign a transmit power which is set based on the vehicle speed, or the vehicle itself may set the transmit power base on its speed, wherein the maximum transmit power is not exceeded.

Vehicles transmit their PLES messages in PECRA with IDMA, using the assigned seed and a transmit power limited by the LMF. The vehicle could use the suggested time periodicity/instants to maximize SINR in normal working points. However, the LMF assigns/updates seeds such that vehicles may also decide to transmit PLES not in their assigned resources, and the system still is able to handle such transmission. This allow fast reaction to potential critical situations, where a vehicle informs quickly its neighbors about a sudden dangerous situation (e.g. a child running in the street, or a brake failure). Moreover, this allow the system to work also when connectivity with the gNB is not present, since the IDMA doesn't require full synchronization to work and the vehicles could transmit at any time.

The vehicles always try to decode messages coming from other users over PECRA channel, allowing transmitted PLES messages to enrich their perception layer, i.e. their road awareness.

Once the PECRA channel is setup to share such information, it is proposed to create a protocol in NR to allow different applications to quickly share PLES messages between themselves in a standardized way through PECRA.

In the following, some more implementation details of example embodiments are described.

As mentioned above, according to some example embodiments, IDMA is applied. The technique of reordering or shuffling the data is known as "Interleaving". The strategy used has an impact on the performance of the system in terms of complexity, and spectral efficiency. According to some example embodiments, the "Prime Interleaver" strategy is considered that builds the interleaving sequence or pattern only based on a seed "p" by considering the Galois Field :

Given the sequence length N, the interleaving pattern is derived as:

( 2 = (1 + p) mod N

. 3 = (1 + 2 ) mod N

n = (1 + (n— 1) p)mod N

An example of interleaving and de-interleaving is shown in Fig. 3.

In the following, some further details concerning the PECRA scenario are described by referring to Fig. 4, where an LMF manages an area with multiple gNBs. Its main tasks are as follows:

Authentication of new vehicles in the network, and assignment of the seeds (see Fig. 3), that will be used by the vehicle to generate their interleaving pattern. The seeds are assigned based on the region where the vehicle is, if it changes the region, a new seed must be assigned. This is done to avoid seeds interference.

The region described above is defined as a seed region. The seed region can be defined by the LMF itself. If there is a huge traffic, it is possible to reduce the size of the seed region in order to increase the reuse factor of the seed inside the area, on the other hand, if the traffic is low, it is possible to increase the size of the seed region so that the rate of seed changes is low. However, the maximum size of the seed region is the area under the control of the LMF.

Reservation of PECRA RBs (as examples for time-frequency resources). This can be done statically or dynamically adapting to the environment parameters such as the number of vehicles and a target level of Quality of Service (QoS). The RB can be also reserved on a regional bases, which means that for a given area, there are fixed RB to be considered, therefore, PECRA users can select the proper RB based on their position.

Note that since the vehicles transmit the situation about the environment they sense, they basically act as relays by propagating the PECRA information message. They can also relay information previously received by other vehicle through PECRA to other vehicles. This allows to communicate PLES over PECRA, even when no reliable and continuous connectivity to the infrastructure is available (since the system just needs to know the IDMA seed and doesn't require scheduling).

In the following, the reception of the PLES messages by the vehicles in PECRA is described : Each vehicle has a Neighbors List (NL), which contains information about the users within a certain radius w.r.t the user position. The NL is derived from the PECRA information message shown in Fig. 5 which is described in the following.

This information can be periodically broadcasted from the gNB or updated with smaller messages containing only few objects' information, e.g. when a seed change happens.

The interleaving patterns of the users in the NL are built using Galois Field described above in connection with Fig. 3. These are used to decode the PLES messages sent from the vehicles to the NL. However, this is only an example, and embodiments are not limited to using the Prime Interleaver, but any interleaving strategy can be used.

The transmission power in PECRA is upper-limited for each vehicle by the LMF with proper signaling, however, the users can adapt their TX power based on their speed. This is justified by the fact that the intervention time (time to stop) in case of a criticality depends on the speed.

In the following, the PECRA message flow shown in Fig. 5 is described in some more detail.

In this example, it is assumed that two new cars arrive, having the IDs ID1 and ID2. First, the new cars have to authenticate with the LMF, as indicated in the upper half of Fig. 5 by "setup/maintenance". In particular, in Mil, the new car ID1 exchanges authentication and handshake procedures with the LMF. In M12, the car ID1 transmits its ID, position and speed to the LMF. In M13, the LMF transmits the assigned seed, PECRA RBs, maximum transmission (TX) power, and preferred transmission interval to the car ID1. M21 to M23 are carried out with respect to new car ID2 and fully correspond to Mil to M13. After this, the PECRA operations can be carried out, as indicated in M4 and M5. That is, each car sends a PLES message which includes the number of objects and, for each object, object ID, position, dimensions, heading, confidence, PECRA shared and PECRA seed information. These messages are not only exchanged between cars ID1 and ID2, but also transmitted to other neighbors, as described above.

As mentioned above, the scheme according to some exemplary embodiments involve half-duplex communications. This is described in the following in more detail by referring to Fig. 6, which illustrates a summary of "perception layer" sharing over the NOMA channel. In this example, the ordinate shows six different cars (Carl to Car6), while the abscissa shows time blocks on the NOMA channel.

As can be observed from Fig. 6, when a vehicle is transmitting, is not able to receive and vice-versa. However, this will not affect the context sharing. Indeed, in the example in Fig.6, if cars 3 and 5 transmit simultaneously, they will not "hear" each other. Since all the others vehicle are listening, they will update their perception layer according to the information sensed from the 2 cars. When the car 2 will sends its perception layer two blocks after, this includes the missed information due to the simultaneous transmission from cars 3 and 5.

It is noted that this happens only if the car is in half duplex mode. With full duplex capabilities, the cars could both transmit and receive, thus all of this would not be necessary.

Moreover, according to a further exemplary embodiment random transmit instants from vehicles can be configured (e.g. with random exponential time between one transmission and the following one, with the average that can be configured by the gNB for each vehicle. Note that this transmit times may also depend on the object's speed). In the following, some more details concerning the Perception Layer Enrichment via Sharing PLES) are described.

The onboard sensors of the vehicles detect the objects (pedestrians, cyclists, vehicles etc.) visible to the vehicle, these objects are described in the perception layer of the vehicle as position, speed and heading, each with its related confidence level.

Two PLES message formats are considered :

The first PLES message format is ordinary PLES, which contains a list of the objects relevant by the vehicle (Number of objects will be the first field). At least one object is shared (the first is the one corresponding to the transmitter), and for each object the following parameters are provided :

Object ID;

Position;

Dimensions;

Speed;

Heading;

Confidence;

PECRA Shared : a flag that indicates if the object was detected by the Car sensors or it was merged from others PLES;

PECRA Seed Information : an optional field related to objects able to transmit PECRA messages. It contains the seed of the vehicle. This allows other vehicles to detect approaching users that were not close before, thus not signaled by the LMF. For instance, if B sees A and C (and A doesn't know about C), it can send info about both around. Then A can pick up the PECRA seed of C and start decoding PLES also from that vehicle.

PECRA New Seed Information : if the seed of an object is being changed, an optional field can be used to signal this to the neighboring objects. The second PLES message format is alert PLES, which is a message sent if the vehicle detects a collision, the proposed message has the following fields:

Collision position;

Collision time;

Confidence;

Suggested action : e.g. slow down, break.

It is noted that the parameters for the two PLES message formats are examples, and may be changed as required .

In the following, details regarding Physical Layer are described, wherein it is focused on the signal model of V2V IDMA. It is noted that any generic IDMA scheme can be used in PECRA. As one example embodiment, a new V2V IDMA scheme is proposed, that modifies conventional IDMA. The advantages of this V2V IDMA is to have better performance in terms of computational complexity (lower BER in the first IDMA PIC iterations), especially at high SINR regions (typical for such short-range transmissions). V2V IDMA may also be referred to as V2V NOMA.

In Fig . 7, the transmitters of k-th vehicle in a /^-vehicle traditional IDMA and V2V IDMA are presented. The traditional IDMA system is described, for example, in Ping, Li; Liu, Lihai; Wu, Keying; Leung, W. K.; "Interleave- Division Multiple-Access," IEEE Trans. Wireless Commun ., Vol . 5, No. 4, pp. 938-947, Apr. 2006. In the traditional IDMA system, the raw bits dk will be processed by conventional repetition coding (REP) after FEC encoding (ENC), and the digital modulation (MOD) and user-specific interleaving will be exploited for the whole data sequence.

In the following, a general exemplary embodiment for a V2V IDMA transmitter is described . According to this, the interleaving division multiple access (IDMA) is applied for transmitting data by applying user-specific interleaving to raw data, and applying user-specific repetition after the interleaving . According to a general exemplary embodiment for a V2V IDMA receiver, the interleaving division multiple access (IDMA) is applied for receiving data by applying linear a pre-filtering algorithm (e.g. MMSE).

Hence, according to the above exemplary embodiment, in order to realize linear MMSE at IDMA receiver, user-specific interleaving, and user-specific repetition after the interleaving are performed.

Furthermore, the "user-specific repetition" is a wide-sense "repetition". For instance, in the following example embodiment, repetition coding plus user- specific scrambling can realize the user-specific repetition. The purpose is as follows: With repetition after interleaving, the structure to realize MMSE at the receiver is ready. With user-specific repetition, the matrix inversion in MMSE can be applicable. The user-specific repetition may be referred to as user-specific repetition encoding and/or scrambling, for example.

Hence, in V2V IDMA as described above, user-specific interleaving and then user-specific repetition are exploited. In the following, a more detailed exemplary embodiment is described, according to which the user-specific repetition is realized by normal repetition coding and user-specific scrambling, which is only one of the possible approaches, to realize user- specific repetition.

In the V2V IDMA system, the raw data d_k will be typically small packet data sequence, the order of REP and user-specific interleaver will be exchanged. In return, this can enable the low cost linear pre-filtering, e.g. Minimum Mean Square Error (MMSE) algorithm. It will be exhibited in the following discussion, that the philosophy of V2V IDMA establishes a new trade-off between the short-term high performance with low latency and long-term high converged performance. The system equation is given by

where h_k stands for the wireless channel between k-th vehicle and the receiver, and z denotes Additive White Gaussian Noise (AWGN) with noise power spectral density No = 2s². It is noted that that the bit-level user-specific scrambling is exploited. It will be exhibited in the following section that the scrambling coefficient C_k can facilitate the functionality of linear MMSE pre filtering, and is defined as

2p >_k(n)

c_k[n] exp j (2)

N

where operator q>k(·) denotes a user-specific integer generator with respect to the discrete time index n, and N is an integer. It is noted that a user divides the circle equally to N parts, so that there are N possible phase components, used for scrambling. Obviously, the larger the N is, the more randomness will be introduced. Considering multiple users in the V2V IDMA system, this enables the matrix inversion in the operation of linear receiver. In V2V IDMA scheme, it is important to exchange both the user-specific interleaving and scrambling information between the vehicles. According to example embodiments, as described above, Prime Interleaver strategy is applied to build the interleaving pattern only based on a prime p. The new interleaved index h can be obtained as

where n denotes to the original index of a sequence with given length N. Thus, the prime p can be regarded as PECRA seed to generate interleaving and scrambling pattern, defined in the original PLES information field to the road user. This allows other road users to detect approaching users that did not appear before, who were not signaled by the current LMF.

In the following, the detection and estimation algorithms are described. In Fig. 8, the V2V IDMA transmission of K data streams is illustrated. The data block length is N, and R stands for the repetition factor, given by the reciprocal of the repetition rate R_r. Notice that the user-specific interleaving takes place only within the original data block. Thus, the same data symbol is superimposed in a synchronized manner after repetition, which allows to represent the non-linear interleaving-based equation system as a linear equation system. Hence, the V2V IDMA system equation can be reformulated as y = Hs + n (4) with y = [yi, y2, , YR]^T , s = [si , S2, , SK]^T and n = [ni, rt2, , HR]^t. The K x R effective channel matrix H is given by

Obviously, the user-specific scrambling coefficient cv, with 1 £ k £ K and 1 < r £ R, plays a very important role, by introducing randomness to guarantee the matrix inversion to compute MMSE pre-filtering weight as w = (H^hH + /VoI)-¹H^H. (6)

The MMSE post-processing noise is still assumed to be complex Gaussian distributed, and can be thus computed as

Thus, the K signal streams can be detected by applying the MMSE prefilter, i.e. s_k = wy. The Log-Likelihood Ratio (LLR) value of the j-th bit in the k- th data stream can be obtained by

where a, stands for the /- th signal constellation, and A¹] and A°j denote the subsets of the QAM constellation candidates, whose j- th bit is 0 and 1, respectively. According to example embodiments an Interleave Division Multiple Access (IDMA) detector is concatenated to the MMSE pre-filtering, which is one candidate solution among the 5G NOMA candidates. IDMA exploits both narrow sense code and wide sense codes, e.g. repetition code, jointly with layer-specific interleaving. As being the most amazing part of IDMA, Elementary Signal Estimator (ESE) establishes a statistics-based soft Parallel Interference Cancellation (PIC) processing chain iteratively. Being supported by central limit theorem, the superposition of multiple signal layers makes the Gaussian Approximation (GA) within ESE operate more and more properly, even if the number of the layers increases. The extrinsic information delivered by ESE can be computed as

where p(y[n] \ d_k[n]) denotes the conditional Probability Density Function (PDF) of receive signal y estimated and improved through a couple of iterations. Especially, for the first iteration, the soft-out information from MMSE in (8) will be exploited to serve as the a priori information for ESE. Thus, it is expected that this will accelerate the convergence of V2V IDMA, modeled in Fig. 5, and will conditionally outperform traditional IDMA at first or second iteration to satisfy the latency constraint. Thus, according to a general exemplary embodiment, a V2V IDMA transmitter may apply the interleaving division multiple access (IDMA) for transmitting data by processing raw data by encoding (ENC in Fig. 7), processing the encoded raw data by a user-specific interleaver, processing the interleaved data by repetition coding (REP in Fig. 7), applying use-specific scrambling to the encoded data, and performing a digital modulation (MOD in Fig. 7) on the scrambled data.

Accordingly, a V2V IDMA receiver according to exemplary embodiments, may apply the interleaving division multiple access (IDMA) for receiving data by applying linear a pre-filtering algorithm, for example a linear Minimum Mean Square Error (MMSE) algorithm whose weight are given by the vector w described above in formula (6)

Summarizing, according to some exemplary embodiments, in the V2V IDMA scheme, the order of interleaver and repetition coding (REP) is exchanged (Fig. 7). With this modification, it is possible to apply MMSE at the IDMA receiver (Fig. 8). It is noted that especially MMSE is not applicable by traditional IDMA (as shown in the upper half of Fig. 7) at all. In Fig. 8, It is shown that the user-specific interleaving only takes place in the original data block (N symbols), and the interleaved block will be repeated. With this modification to the traditional IDMA, the V2V IDMA can be benefitted from MMSE pre-filtering additionally.

In some example embodiments described above, a MAC layer and PHY layer design is provided targeting to Perception Sharing in a vehicular network. By standardizing Perception Layer Enrichment via Sharing (PLES), Perception Enrichment Channel for Road Application (PECRA) information, which is fundamentally the secure information for driving the vehicles, is assumed to be transmitted in a superposition manner. PECRA based Perception Sharing can significantly reduce the scheduling overhead and the latency in vehicular network. In PHY layer, this is supported by Non-Orthogonal Multiple Access (NOMA) concept. According to some example embodiments, Interleave Division Multiple Access (IDMA) is adopted, which belongs one of the NOMA solutions under 5G context. Further, a modified approach V2V IDMA is proposed, which changes the order of user-specific interleaving and repetition coding at the transmitter and introduces user-specific scrambling additionally, in order to enable low-cost linear MMSE pre-filtering at the receiver. Numerical results show that the V2V IDMA can still accommodate and support the data detection and decoding for 15 vehicles simultaneously. Especially, the V2V IDMA is low-complexity, and conditionally outperforms traditional IDMA for small data packet, if none iteration or only one iteration is allowed at the receiver, in order to reduce the complexity and fulfill the latency prerequisite.

The above-described example embodiments are only examples and may be modified.

For example, according to some example embodiments, the PECRA controller is provided in an LMF, and the connection between the LMF and the vehicles is provided by base stations such as gNBs. However, the embodiments are not limited to this arrangement. For example, the functionality of the PECRA controller may be provided in one of the gNBs or in another suitable network element.

Furthermore, in some example embodiments, the vehicles capable of PECRA are cars. However, the embodiments are not limited thereon, and the vehicles may be any kind of vehicles, including motor bikes, busses, lorries, trams, street cars, trains etc.

Names of network elements, protocols, and methods are based on current standards. In other versions or other technologies, the names of these network elements and/or protocols and/or methods may be different, as long as they provide a corresponding functionality. In general, the example embodiments may be implemented by computer software stored in the memory (memory resources, memory circuitry) 12, 22, 32 and executable by the processor (processing resources, processing circuitry) 11, 21, 31 or by hardware, or by a combination of software and/or firmware and hardware.

As used in this application, the term "circuitry" refers to all of the following :

(a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and

(b) to combinations of circuits and software (and/or firmware), such as (as applicable) : (i) to a combination of processor(s) or (ii) to portions of processor(s)/software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and

(c) to circuits, such as a microprocessor(s) or a portion of a microprocessor(s), that require software or firmware for operation, even if the software or firmware is not physically present.

This definition of "circuitry" applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term "circuitry" would also cover an implementation of merely a processor (or multiple processors) or portion of a processor and its (or their) accompanying software and/or firmware. The term "circuitry" would also cover, for example and if applicable to the particular claim element, a baseband integrated circuit or applications processor integrated circuit for a mobile phone or a similar integrated circuit in server, a cellular network device, or other network device.

The terms "connected," "coupled," or any variant thereof, mean any connection or coupling, either direct or indirect, between two or more elements, and may encompass the presence of one or more intermediate elements between two elements that are "connected" or "coupled" together. The coupling or connection between the elements can be physical, logical, or a combination thereof. As employed herein two elements may be considered to be "connected" or "coupled" together by the use of one or more wires, cables and printed electrical connections, as well as by the use of electromagnetic energy, such as electromagnetic energy having wavelengths in the radio frequency region, the microwave region and the optical (both visible and invisible) region, as non-limiting examples.

The memory (memory resources, memory circuitry) 12, 22, 32 may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory, and non- transitory computer-readable media. The processor (processing resources, processing circuitry) 11, 21, 31 may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on a multi core processor architecture, as non-limiting examples. It is to be understood that the above description is illustrative of the invention and is not to be construed as limiting the invention. Various modifications and applications may occur to those skilled in the art without departing from the true spirit and scope of the invention as defined by the appended claims.

Claims

1. An apparatus, in a vehicle, comprising

at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform :

receiving configuration information for a non-orthogonal multiple access channel including resources to be used for the non-orthogonal multiple access channel,

detecting an environment of the vehicle, and

2. The apparatus according to claim 1, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to further perform :

transmitting the multicast transmission messages to one or more other vehicles, and/or

receiving the multicast reception messages from one or more other vehicles, wherein the multicast reception messages comprise information about a detected environment or the one or more other vehicle.

3. The apparatus according to claim 1 or 2, wherein the received configuration information comprises at least one of the following :

information concerning resources to be used for transmitting multicast transmission messages,

information concerning resources to be used for receiving multicast reception messages, information for coding to be applied for the multicast transmission message,

information for decoding multicast reception messages,

a maximum transmit power to be applied for transmitting the multicast transmission messages, and

an assigned time transmission timing.

4. The apparatus according to any one of the claims 1 to 3, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to further perform :

transmitting the multicast transmission message on a resource, which is assigned to the apparatus by the received configuration information, or transmitting the multicast transmission message on a different resource not assigned to the apparatus when a certain condition is fulfilled.

5. The apparatus according to any one of the claims 1 to 4, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to further perform :

including information from one or more received multicast reception messages into the multicast transmission message to be transmitted.

6. The apparatus according to any one of the claims 1 to 5, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to further perform :

applying interleaving division multiple access on the non-orthogonal multiple access channel for transmitting the multicast transmission messages and/or receiving the multicast reception messages.

7. The apparatus according to claim 6, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to further perform :

applying the interleaving division multiple access for transmitting data by

applying user-specific interleaving to raw data, and applying user-specific repetition after the interleaving.

8. The apparatus according to claim 6, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to further perform :

applying the interleaving division multiple access for receiving data by applying linear a pre-filtering algorithm.

9. The apparatus according to any one of the claims 6 to 8, wherein a seed is assigned to the apparatus, based on which the interleaving division multiple access is applied.

10. The apparatus according to claim 9, wherein the seed is included in the received configuration information.

11. The apparatus according to any one of the claims 1 to 10, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to further perform :

receiving information concerning neighbor objects and

providing a neighbor list based on the received information concerning neighbor objects.

12. The apparatus according to any one of the claims 1 to 11, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to further perform :

authenticating with a network control element for obtaining the configuration information for the non-orthogonal multiple access channel from the network control element.

13. The apparatus according to claim 12, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to further perform : transmitting an estimated or detected location of the vehicle to the network control element.

14. The apparatus according to any one of the claims 1 to 13, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to further perform :

setting a transmit power for transmitting multicast transmission messages based on the speed of the vehicle.

15. The apparatus according to any one of the claims 1 to 14, wherein a first message format of the multicast transmission messages and/or the multicast reception messages comprise information about at least one object, wherein for each object at least one of the following parameters are provided :

an object identifier;

position of the object;

dimensions of the object;

speed of the object;

heading of the object;

confidence concerning the detection of the object;

collision position;

collision time;

confidence; and/or

suggested action.

16. An apparatus, comprising

obtaining information concerning vehicles in a predetermined area, each vehicle capable of detecting an environment of the vehicle,

transmitting the configuration information to each vehicle.

17. The apparatus according to claim 16, wherein the configuration information comprises at least one of the following :

information concerning resources to be used for transmitting and/or receiving multicast messages,

information for coding and/or decoding to be applied for the multicast messages,

a maximum transmit power to be applied for transmitting the multicast messages, and

a suggested time transmission timing.

18. The apparatus according to claim 17, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to further perform :

setting the maximum transmit power for transmitting multicast transmission messages based on the speed of the vehicle.

19. The apparatus according to any one of the claims 16 to 19, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to further perform : authenticating a vehicle for providing the configuration information for the non-orthogonal multiple access channel.

20. The apparatus according to claim 19, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to further perform :

transmitting the configuration information for each vehicle to all authenticated vehicles.

21. The apparatus according to claim 19 or 20, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to further perform :

preparing the configuration information based on the number of the vehicles and capabilities of the authenticated vehicles.

22. The apparatus according to claim 21, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to further perform :

obtaining a location of a vehicle, and

preparing the configuration information for the vehicle also based on the locations of the vehicle.

23. The apparatus according to any one of the claims 16 to 22, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to further perform : assigning a seed to be used for interleaving division multiple access on the non-orthogonal multiple access channel for each vehicle and

including the seed in the configuration information.

24. The apparatus according to claim 23, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to further perform : transmitting the configuration information to the vehicles via at least one base station.

25. An apparatus, in a base station, comprising

receiving, from a network control element, configuration information for a non-orthogonal multiple access channel including resources to be used by vehicles for exchanging multicast messages including information about the detected environment between the vehicles, and

transmitting the received configuration information to each vehicle.

26. The apparatus according to claim 25, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to further perform :

estimating or detecting a location of the vehicle, and

transmitting the estimated or detected location of the vehicle to the network control element.

27. A method comprising

receiving, in a vehicle, configuration information for a non-orthogonal multiple access channel including resources to be used for the non-orthogonal multiple access channel,

detecting an environment of the vehicle, and

28. The method according to claim 27, further comprising : transmitting the multicast transmission messages to one or more other vehicles, and/or

29. The method according to claim 27 or 28, wherein the received configuration information comprises at least one of the following :

information concerning resources to be used for receiving multicast reception messages,

information for coding to be applied for the multicast transmission message,

information for decoding multicast reception messages,

an assigned time transmission timing.

30. The method according to any one of the claims 27 to 29, further comprising :

transmitting the multicast transmission message on a resource, which is assigned to the vehicle by the received configuration information, or

transmitting the multicast transmission message on a different resource not assigned to the vehicle when a certain condition is fulfilled.

31. The method according to any one of the claims 27 to 30, further comprising :

32. The method according to any one of the claims 27 to 31, further comprising :

33. The method according to claim 32, further comprising :

applying the interleaving division multiple access for transmitting data by

applying user-specific interleaving to raw data, and

applying user-specific repetition after the interleaving.

34. The method according to claim 32, further comprising :

35. The method according to any one of the claims 32 to 34, wherein a seed is assigned to the vehicle, based on which the interleaving division multiple access is applied.

36. The method according to claim 35, wherein the seed is included in the received configuration information.

37. The method according to any one of the claims 27 to 36, further comprising :

receiving information concerning neighbor objects and

38. The method according to any one of the claims 27 to 37, further comprising : authenticating with a network control element for obtaining the configuration information for the non-orthogonal multiple access channel from the network control element.

39. The method according to claim 38, further comprising :

transmitting an estimated or detected location of the vehicle to the network control element.

40. The method according to any one of the claims 27 to 39, further comprising :

41. The method according to any one of the claims 27 to 40, wherein

a first message format of the multicast transmission messages and/or the multicast reception messages comprise information about at least one object, wherein for each object at least one of the following parameters are provided :

an object identifier;

position of the object;

dimensions of the object;

speed of the object;

heading of the object;

confidence concerning the detection of the object;

new seed information comprising a changed seed of an object; and a second message format of the multicast transmission messages and/or the multicast reception messages comprise information about a detected collision, wherein at least one of the following parameters are provided : collision position;

collision time;

confidence; and/or

suggested action.

42. A method, comprising

transmitting the configuration information to each vehicle.

43. The method according to claim 42, wherein the configuration information comprises at least one of the following :

a suggested time transmission timing.

44. The method according to claim 43, further comprising :

45. The method according to any one of the claims 42 to 44, further comprising :

authenticating a vehicle for providing the configuration information for the non-orthogonal multiple access channel.

46. The method according to claim 45, further comprising :

47. The method according to claim 45 or 46, further comprising :

48. The method according to claim 47, further comprising :

obtaining a location of a vehicle, and

49. The method according to any one of the claims 42 to 48, further comprising :

assigning a seed to be used for interleaving division multiple access on the non-orthogonal multiple access channel for each vehicle, and

including the seed in the configuration information.

50. The method according to claim 49, further comprising :

transmitting the configuration information to the vehicles via at least one base station.

51. An method, comprising

receiving, in a base station from a network control element, configuration information for a non-orthogonal multiple access channel including resources to be used by vehicles for exchanging multicast messages including information about the detected environment between the vehicles, and

transmitting the received configuration information to each vehicle.

52. The method according to claim 51, further comprising : estimating or detecting a location of the vehicle, and

53. A computer program product comprising code means for performing a method according to any one of the claims 27 to 52 when run on a processing means or module.

54. The computer program product according to claim 53, wherein the computer program product is embodied on a computer-readable medium, and/or the computer program product is directly loadable into the internal memory of the computer and/or transmittable via a network by means of at least one of upload, download and push procedures.