.Description

Embodiments of the present invention refer to a method for managing grant free resources, having the aim to reduce colliding transmissions, to a method for managing grant free resources having the focus on the selection of the MCS (modulation coding scheme) and the TBS (transmission block size). Further, embodiments refer to a method for managing grand free resources by use of a DMRS (demodulation reference signal). Another embodiment refers to a corresponding computer program. A further embodiment refers to a controller for managing grant free resources according to one of the above discussed approaches. Further embodiments refer to a base station and to a communication system using the above described entities.

The solution for identifying collided UEs (or rather collided sub-channels allocated by different UEs) can be used to implement a partially colliding non-orthogonal multiple access (NOMA) scheme. Hence, an advanced SIC receiver will be able to identify where to decouple collided UEs on the collided sub-channels.

In the 3GPP 5th generation (5G) New Radio (NR) in the following study and work items: ultra-reliable and low-latency communication (URLLC), NR for unlicensed band (NR-U), non-orthogonal multiple access (NOMA), and vehicle-to-anything (V2X), a Quality-of- Service (QoS) based Grant Free (GF) uplink (UL) adaptive scheme is proposed to enhance the reliability, latency of time critical communication, and signaling overhead.

For GF resource allocation, a network radio resource controller (RRC), a base-station, an access point, or a mobile terminal (user-equipment (UE)) assigns for a group of UEs a group of consecutive physical resource blocks (PRBs) in a specific frequency band for a certain period. This is called (pre-)configured grants type 1 or type 2.

To configure the pre-configured (periodic) grants, the base-station of the network (representing the radio resource controller (RRC)) sends the following information to the assigned UEs [1]:

^• Periodicity and offset (time-domain) of a resource with respect to the subframe number (SFN)=0

• Frequency domain resource allocation (Allocated physical resource-blocks (PRB)) • UE-specific DMRS configuration

• An MCS/TBS value (in legacy new-radio, Re! 15, those are not overridden by the

UE)

• Number of repetitions K in time domain

• Power control related parameters

• Number of HARQ-Processes

The current legacy mechanism does not suffices the all the requirements for, e.g., URLLC and V2X, i.e., including latency and reliability. The main drawback is that collisions between UEs may occur in unmanaged manner. In this case, if two or more UEs are transmitting on the same resources, the collision occurs.

Additionally, with the legacy description, the modulation coding scheme (MCS) and the transmit block size (TBS) are also fixed and not adapted to the collision dynamic situations. Moreover, at the receiver side, decoding becomes worse if the UEs are transmitting on complete overlapping resources. On the other hand, if the colliding UEs are partially overlapping, detecting those UEs is even problematic due to insufficient DMRS isolations. Therefore, there is a need for an improved approach.

An objective of the present invention is to provide an enhanced approach for managing grant free resources.

This objective is solved by the subject matter of the independent claims.

An embodiments provides a method for managing grant free resources or a resource pool for a plurality of user equipments. The method comprises the following basic steps:

• Splitting the bandwidth of the grant free resources into a plurality of subchannels to be used by each of the plurality of user equipments for a respective transmission to obtain a subchannel configuration;

• Computing a transmission position within the subchannel configuration by using a transmission counter or a counter mapped to an (temporary) ID of the respective user equipment of the plurality of user equipments, wherein the step of computing is performed by the respective user equipment of the plurality of user equipments; and • Rotating/hopping/shifting a colliding transmission position over the plurality of subchannels of the subchannel configuration.

According to a further embodiment / alternative wording the method may comprise the step of dividing configured resources (configured grants, resource pools of grant free resources) into different resources. Alternatively, this means that the step of splitting the bandwidth of the grant free resources comprises dividing the configured resource

(configured grants, resource pools or grant free resources) into different resources.

According to an alternative embodiment, the method may comprise the following three basic steps:

• Dividing the configured grant resources or resources of the resource pool into different resources corresponding to a plurality of subchannels to be used by each of the plurality of user equipments for a respective transmission to obtain a subchannel configuration;

• Computing a transmission position within the subchannel configuration by using a transmission counter or a counter mapped to an (temporary) ID of the respective user equipment of the plurality of user equipments, wherein the step of computing is performed by the respective user equipment of the plurality of user equipments; and

• Rotating/hopping/shifting a colliding transmission position over the plurality of subchannels of the subchannel configuration.

Embodiments of this first aspect are based on the finding that by adapting the grant free transmission (GF transmission) a transmission can be realized, e.g., on the uplink (UL) having a maximum collision ratio which does not exceed the maximum UEs utilization ratio (i.e., maximum number of the UEs divided by the number of the available sub- channels). This is done by rotating/shifting/hopping the colliding UEs transmission over the allocated sub-channels, for example for the initial transmission so do redundancy version repetitions. Due to the rotating/shifting/hopping a collision, if available, is rotated/shifted/hopped over the available sub-channels to guarantee equal average sub- channel power (if needed) or to distribute the interference over the frequency band. In other words, this means that the rotating/shifting of the colliding transmission positions comprises a reshuffling of the colliding transmission position across the bandwidth. This may be performed by use of deterministic hops or with random hopping sequences. The discussed approach helps to meet URLLC requirements by supporting lower collision values and better meeting the target QoS/BLER of the URLLC scheme. Extension to higher spectral efficiency is also possible in the same way.

Regarding the sub-channels, it should be noted that a sub-channel may be defined as the following:

• Consecutive PRBs with a length LCH PRBS

• Non-consecutive PRBs goups bundled in a virtual consecutive subchannel. Hence, there is a mapping between the virtual RB (vRB) and the PRB.

In order to enable to compute the transmission position, the method may comprise the step of providing the transmission counter. This step may, for example, be performed by a base station or a network controller. According to further/alternative embodiments, the sub-channel configuration is periodic, so with each submission opportunity the respective user equipments increments its transmission counter and calculates the corresponding sub-channel ID/sub-channel number via which it shall send on. According to further embodiments, each of the plurality of user equipments starts its transmission according to the computed transmission position and/or from a frequency index that matches to the start of any of sub-channel indices. Express in other words, it is allowed for each user equipments to start the transmission from a frequency index that matches to the start of any of the sub-channel indices.

Additionally - according to further embodiments - an information regarding the respective sub-channel of the plurality of sub-channels to be used by the respective user equipments may be provided. Here, the step of providing information is performed also by a base station or the network controller. According to embodiments, this information may comprise providing information regarding the respective subchannel (SC) of the plurality of subchannels (SC) to be used by the respective user equipment, wherein the step of providing information is performed by a base-station or a network controller, wherein the information comprises: M (M sub-band size), b _{1 t} and LTC _j (O), wherein (At the eNB side) bi (overloading factor) is calculated as follows: b _[ = N/L; and wherein (At each TO) the UE calculates L (sub-channels) as follows: L = W/M; and wherein each UE calculates L ₀ (overloaded sub-channels) as follows: L ₀ =

1(bi - 1) * L + 0.5J; and wherein each UE calculates LTC _j (TO) as follows: LTC _j (TO) = (LIC _j (TO - 1) + 1)%(L + L ₀ ); and wherein (at each TO) the following calculation is performed for i _n :

LTC _j (TO), LTCi(TO) < L

n (TO) = . Here, N is the number of UEs

(LTCi(TO) - L ₀ )%L, LTC _j (TO) > L

and W total number of GF PRBs.

According to embodiments, the computing is performed for every one of the plurality of user equipments in a same manner (for example, it can be always one sub-channel) or wherein computing is performed for every one of the plurality of user equipments in a different/random manner. Analogously, the rotating/hopping/shifting may - according to embodiments - be performed for every one of the plurality of user equipments in a same manner, e.g., always one sub-channel, or in a different/random manner.

According to further embodiments, the method may comprise the step of designing a relation between the plurality of sub-channels and a transmission counter to achieve a lowest collision probability for each UE. This step may be performed, for example, such that the collision does not exceed the maximum utilization ratio (when assuming they have the same available rate of packets).

According to embodiments, each of the plurality of sub-channels is defined by consecutive PRBs with lengths Lies PRBS or by non-consecutive PRBs groups bundled in a virtual (consecutive) sub-channel. Each sub-channel may be composed out of one or more physical resource blocks.

According to further embodiments, the computing is performed such that : • The collision is minimized to the maximum utilization (overload) factor b, for example PJ=(#UEs)/(#Sub-channeis) (note if the overload factor b_I < 2, it is always guaranteed to have collision free sub-channels (as if they are allocated by grant-base) and collision based sub-channels); and/or

• The sub-channel with collision can be predicted (at the base-station); and /or

• The collided resources can be confided in a certain band (or hopped band/pattern).

According to further embodiments, some UEs, e.g., UEs having high data rate requirements are allowed to span or use more than one sub-channel. This is type of spanning may be based on a so-called UE (required) traffic model.

According to a preferred embodiment, a design for managing the grant free transmission, also known as preconfigured resources, is proposed, wherein the design is based on a splitting of the total bandwidth into multiple sub-channels.

The sub-channel itself is composed of one or more (plurality) of physical resource blocks (namely PRBs). The UE is only allowed to transmit starting from a frequency index that matches to the start of any of sub-channel indices. The number of the sub-channel indices can be computed by defining the maximum channel length (number of PRBs) and the total number of PRBs in a bandwidth W. The base-station (or the network, represented by the RRC) can distribute a logical transmission counter (LTC), where the UE (from its (LTC) or a counter mapped to its temporary ID) can compute the transmission position. In this case, multiple methods can reduce (or confined) the collision to the minimum value based on a utilization or an overload factor. The collision position can be reshuffled across the grant whole bandwidth W, i.e., with a deterministic hops or random hopping sequence. For K-repetition, the proposed LTC identification shall be used to keep the collision reduced/ managed for the redundancy versions similar to the initial version transmission occasion.

According to an alternative wording the configured resources, like configured grants, resource pools of grant free resources or pre-configured resources, are divided or spitted. Starting from this surrounding another embodiment provides a method for managing grant free resources for a plurality of user equipments. This method comprises: • Splitting the bandwidth of the grant free resources into a plurality of subchannels to be used by each of the plurality of user equipments for a respective transmission to obtain a subchannel configuration;

• Dividing the configured resources (configured grants, resource pools or grant free resources) into different resources;

• Computing a transmission position within the subchannel configuration by using a transmission counter or a counter mapped to an (temporary) ID of the respective user equipment of the plurality of user equipments, wherein the step of computing is performed by the respective user equipment of the plurality of user equipments; and

• Rotating/hopping/shifting a colliding transmission position over the plurality of subchannels of the subchannel configuration.

A further embodiment provides a method for managing configured grant resources or a resource pool for a plurality of user equipments. This method comprises:

• Dividing the configured grant resources or resources of the resource pool into different resources corresponding to a plurality of subchannels to be used by each of the plurality of user equipments for a respective transmission to obtain a subchannel configuration;

• Computing a transmission position within the subchannel configuration by using a transmission counter or a counter mapped to an (temporary) ID of the respective user equipment of the plurality of user equipments, wherein the step of computing is performed by the respective user equipment of the plurality of user equipments; and

• Rotating/hopping/shifting a colliding transmission position over the plurality of subchannels of the subchannel configuration.

The method, according to further embodiments or according to further aspects, may comprise a step of selecting MCS (modulation coding scheme) and/or TBS (transmit block size). This setting may be based an initial MCS by using a formula or a look-up table enabling to accommodate for more transmissions, e.g., by increasing the MCS over a plurality of sub-channels or to accommodate for higher reliability, e.g., by allocating lower MCS over a plurality of sub-channels.

Embodiments of this second aspect are based on the finding that by selecting the MCS or the TBS the transmission can be optimized for different aims (high date throughput or high reliability). For example, it enables that high data rate UEs are allowed to spend more than a sub-channel based on the UE required traffic model. In this case, the MCS and/or the TBS is selected based on a formula or a look-up table to accommodate for more transmissions. Either the number of the sub-channels or the start of the subchannels is an input to MCS TBS adaption. Additionally, the number of allocated subchannels can be used to adapt the MCS TBS.

According to embodiments, a number of sub-channels or a start of the sub-channel is also an input of the MCS adaption/TBS adaption. According to embodiments, the respective user equipments adaptively selects the appropriate MCS and sub-channel size from the available preconfiguration. According to embodiments, the respective user equipments selects initial/preconfigured MCS and/or initial/preconfigured TBS according to different channel conditions. For example, the respective user equipments can have access to, or uses, different tables/auxiliary tables, wherein each table/auxiliary table may be mapped to different initial/preconfigured MCS and/or initial preconfigured TBS set by a base station or a network controller. Expressed in other words, this means that each table/auxiliary table comprises different initial/preconfigured MCS and/or TBS. Starting from such a table/auxiliary table the respective user equipments selects entry in one of the different tables/auxiliary tables based on the channel conditions.

Starting with GF-type 1 and/or type 2, a preferred embodiment will be described. Here, it is typical that this embodiment uses the step of selecting from a plurality of GF discrete transmission resource configurations in order to meet the target BLER QoS.

According to the spectral efficiency and the possible sub-channel configuration, the RRC configuration has to be overridden by a mapping function or equation. This can be a solution at least Type 2; also it would support type-1 grant-free transmission if the BS would decouple the UE-RRC direct mapping. The UE adaptively select the appropriate MCS and sub-channel size from the available pre-configuration, i.e., this can be all in one BWP or multiple BWP. According to a basic embodiments of the second aspect, a managing method is provided.

The method for managing grant free resources for a plurality of user equipments comprises the following steps:

• Splitting the bandwidth of the grant free resources into a plurality of subchannels to be used by each of the plurality of user equipments for a respective transmission to obtain a subchannel configuration; and

• Selecting MCS and/or TBS adaptively by one of the plurality of user equipments.

According to further embodiments, the one of the plurality of user equipments selects the MCS based on an initial MCS and/or using a formula or a look-up table to accommodate for more transmissions (so as to increase the MCS over a plurality of sub-channels) or to accommodate for higher reliability (so as to allocate lower MCS over a plurality of sub- channels). The number of sub-channels or a start of the sub-channel may be an input to MCS/TBS adaption. The respective user equipments adaptively selects - according to embodiments - the appropriate MCS and sub-channel size from the available preconfiguration. Alternatively, the one of the plurality of user equipments is selected - according to embodiments - initial/preconfigured MCS and/or initial/preconfigured TBS according to the different channel conditions. Here, the respective user equipments can have access to, or uses, different tables/auxiliary tables, wherein each table/auxiliary table may be mapped to a different initial/preconfigured MCS and/or TBS set by a base station or a network controller. Note, each table/auxiliary table can comprise different initial/preconfigured MCS and/or TBS, wherein the respective user equipments selects the entry in one of the different table/auxiliary tables based on the channel conditions.

According to further embodiments and/or further aspects, the DMRS (demodulation reference signal) is selected to guarantee it is a discrete orthogonal code repetition in frequency over the bandwidth, where the lengths of the orthogonal subsequences is such that within each part of a DMRS collision (whether full or partially) the colliding sequence sections remain orthogonal or nearly orthogonal. According to further embodiments, the DMRS can be selected based on a Zadoff-Chu (ZC) code sequence or any different pseudo random (PN) sequence. This can be done, for example, element wise multiplied with orthogonal sequences or sequences that are nearly orthogonal. In this context, nearly orthogonal means a sequence correlation magnitude, for example, less than 0.1. Note, according to embodiments, the colliding user equipment is identified based on the discrete orthogonal code repetition in frequency over the bandwidth. According to further embodiments, the method may comprise the step of implementing a partially colliding non-orthogonal multiple access scheme using discrete orthogonal code repetition. Here, the method may further comprise (according to additional embodiments) identifying successive interference decoding/cancellation based on the discrete orthogonal code repetition for collision identification.

Embodiments of this third aspect are based on the finding that the selection of the DMRS has an influence to the detection probability or detection accuracy of transmission collisions between UEs.

A preferred embodiment of this aspect will be discussed. Depending on the number of PRBs configured for the transmission and the restricted/allowed starting PRBs of the allocation, the UE collision/overlapping, if happens, can only be multiples of PRBs. The set of values of the possible overlap depends on the allowed starting PRBs and the number of PRBs in the allocation. Note, This definition is more general and can allow more starting points than number of subchannels. e.g., for band with 7 PRBs: 1 ,2, 3, 4, 5, 6, 7. With 3 PRBs subchannel size, we have (1 ,2,3) (4,5,6) (7) . In another scheme, where starting points are allowed every 2 PRBS (i.e. 1 ,3,5,7) but with an allocation size of 3 PRBs, we have these allocations: (1 ,2,3) (3,4,5) (5,6,7) (7). In such situation, the DMRS codes has to be designed to improve the detection probability in such situations. The first solution may also result in partial overlapping/collision between UEs and belongs to the category with a restricted starting PRBS of the allocation.

Starting from the above discussed methods for managing grant free resources another embodiment provides another method for managing grant free resources for a plurality of user equipments. This method comprises the steps of:

• Splitting the bandwidth of the grant free resources into a plurality of subchannels to be used by each of the plurality of user equipments for a respective transmission to obtain a subchannel configuration;

* further comprising selecting DMRS to guarantee a discrete orthogonal code repetition in frequency over the bandwidth (to improve the detection probability of collisions); or • further comprising selecting DMRS to guarantee a discrete orthogonal code repetition in frequency over the bandwidth by repeating orthogonal subsequences to form the entire DMRS of the user; or

• further comprising selecting DMRS to guarantee a discrete orthogonal code repetition in frequency over the bandwidth, wherein the length of the orthogonal subsequences is such that within each part of a DMRS collision, whether full or partial, the colliding sequence sections remain orthogonal or nearly orthogonal; and/or

• further comprising selecting DMRS based on Zadoff-Chu (ZC) code sequence or any different Pseudorandom (PN) sequence, element-wise multiplied with orthogonal sequences or sequences that are nearly-orthogonal.

According to embodiments which are directed to all aspects, the methods may further comprise dividing configured resources (configured grants, resource pools or grant free resources) into different resources. Expressed in other words, this means that the method may comprise the step of splitting the bandwidth of grant free resources, wherein this step comprises dividing the configured resources (configured grants, resource pools or grant free resources) into different resources.

The above discussed methods may be performed by use of a computer program. Therefore, another embodiment provides a computer readable digital storage medium having stored thereon a computer program having a program code for performing, when running on a computer, the method according to one of the previously discussed methods.

According to a further embodiment the method may be implemented in hardware. Therefore, another embodiment provides a controller for managing the grant free resources. The controller is configured for

• Splitting the bandwidth of the grant free resources into a plurality of subchannels to be used by each of the plurality of user equipments for a respective transmission to obtain a subchannel configuration, such that the respective user equipment of the plurality of user equipments can compute a transmission position within the subchannel configuration the using a transmission counter or a counter mapped to an (temporary) ID of the respective user equipment of the plurality of user equipments; and

• Rotating/hopping/shifting a colliding transmission position over the plurality of subchannels of the subchannel configuration.

According to another embodiment the controller is configured for

- Splitting (110) the bandwidth (BW) of the grant free resources into a plurality of subchannels (SC) to be used by each of the plurality of user equipments for a respective transmission to obtain a subchannel (SC) configuration; and

- Selecting (260) MCS and/or TBS adaptively by one of the plurality of user equipments.

Note, the controller may be implemented as a shared controller, i.e. , located at one or preferably more entities, like user equipments. This means that the controller is comprised by one or more entities of the communication system (UE, base station, etc.). Of course, the controller can also be implemented within one entity, e.g., within the base station or the network controller.

Another embodiment provides a user equipment with is configured to perform the managing or at least one of the managing steps as has been discussed.

Another embodiment provides a base station or a network controller which is configured to perform the managing as it has been discussed.

Another embodiment provides a communication system comprising at least a base station and one or more user equipments.

Note, the user equipment may be configured to allocate a different number sub-channels and/or resources with DMRS.

Embodiments will subsequently be discussed referring to the enclosed figures, wherein

Fig. 1 shows a schematic illustration of an approach for configured resource management according to a basic embodiment; Figs. 2a, 2b show schematic illustrations for illustrating enhanced embodiments. Alternatively, the controller is configured to perform one of the above discussed approaches;

Fig. 3a shows schematically according to embodiments: GF PRBs divided into L

(=4 in the example) sub-channels;

Fig. 3b shows schematically according to embodiments; GF vRBs divided into L sub-channels (each subchannl has 6 vRBs or 6 PRBs);

Fig. 4a shows schematically according to embodiments; UEs are configured with 5

GF sub-channels (bi =1.4);

Fig. 4b shows schematically according to embodiments; UEs are configured with 5

GF sub-channels (b _] =1.2);

Fig. 4c shows schematically according to embodiments; UEs are configured with 5

GF sub-channels (bi =1.2); here the colliding sub-channel (sub-band) is rotating;

Fig. 4d shows schematically according to embodiments; UEs are configured with 5

GF sub-channels (bi =1.2, known at the receiver); here the colliding subchannel (sub-band) is rotating and UE0 expanded its transmission to 3 subchannels;

Fig. 5 shows schematically UEs which are configured both 5 GF sub-channels, wherein UE2, UE4, UES stop transmission to illustrate further embodiments; UEs are configured with 5 GF sub-channels, where UE2, UE4, UES stopped transmission. In this case also, bi =1.2 (known at the receiver); here the colliding sub-channel (sub-band) is rotating and two UE (UE0, UE3) expanded their transmission to 3 and 2 sub-channels, respectively;

Fig. 6a shows schematically to illustrate further embodiments; Single-DMRS short- orthogonality design (Configuration 1) with a sub-channel based length; Fig. 6b shows schematically to illustrate further embodiments; 2-DMRS short- orthogonality design with a sub-channel length, e.g., configuration 2 where the two DMRS code occupy the same two symbols positions on every user on every sub-channel;

Fig.6c illustrates schematically the use of to illustrate further embodiments; and

Using short/discrete DMRS as a collision locator for decoding non- orthogonal multiple access (NOMA); and

Fig. 7 shows a table to illustrate an approach enabling to select a position of a sub-channel based on a received power strength according to a further embodiment.

Below, embodiments of the present invention will subsequently be discussed referring to the enclosed figures, wherein identical reference numbers are provided to objects/elements/steps having an identical or similar function, so that the description thereof is mutually applicable and interchangeable.

Fig. 1 shows a method 100 during three basic steps, namely steps 110, 120 and 130 which can be performed subsequently to each other.

Within the first step 110 the grant free resources are split into sub-channels. Here, the entire bandwidth of the grant free resources is divided into different portions, also referred to as resource blocks. In other words, this means that the step enables the dividing of the configured resource (configured grants) resource pools or grant free resources into different (subdivided) resources. These subdivided resources of sub-channels are marked by the reference numeral SE1 , SE2, .... SEN. The result of the step 110 is a so-called sub-channel configuration. With the next step 120 a respective transmission position within the sub-channel configuration is computed for and/or for each user equipment. Preferably this step is performed by a respective user equipment. The step positions are marked by the reference numeral SP1 , SP2, SPN. The computing can be performed by use of a transmission counter, e.g., provided by a base station or by a counter mapped in (temporarily ID of the respective user equipment). Starting from this step, now each user equipment knows possible start positions for a preferred transmission or a start position for possible transmission. Now, each user equipment can transmit by use of the respective start positions SP1 , SP2, SPN, however, if there is a colliding transmission, the step 130 enables the solution for spanning this collision transmission over the entire bandwidth EW. To do this, the colliding position is rotated/hopped/shifted over the plurality of sub-channels. Consequently, the colliding position, e.g., SE1 to SE1 occurs once this sub-channel and within the next periodic iteration within the next of another sub-channel. Due to this, the interference/colliding transmission is equally distributed along all channels.

Fig. 2a shows another aspect which mainly starts from the assumption that the bandwidth of the resource pool/grant free resources is split/subdivided. Therefore, the method 200 comprises the step 110 which has been discussed in context with Fig. 1. Optionally, the method 200 may also comprise the steps 120 and 130, wherein this is not required. The method 200 comprises the second basic step 210 of adapting the modulation coding scheme (MGS) and/or of adapting the time block size (TBS). This adaption may be performed starting from an initial MCS/TBS using a formula look-up table, wherein the formula/look-up table comprises MGS and/or TBS order to accommodate for more transmission. Here, the MGS is typically increased over a plurality of sub-channels. Alternatively, the look-up table can also have MCS/TBS enabling to accommodate for higher reliability. Typically, lower MGS is allocated over a plurality of sub-channels. According to further embodiments, a number of the sub-channels or the start position of the respective sub-channel (cf. discussion of Fig. 1) is used as input for the formula/lookup table. According to preferred embodiments, this adaption is performed iteratively in order to achieve an optimum.

Fig. 2b illustrates another embodiment, namely a method for managing grant free resources/resource pool which is also based on the situation that the grant free resources/resource pool are split into sub-channels/different resources. Therefore, the method 250 also comprises the emission step 110 which has been discussed in context with Fig. 1 , Optionally, the method can comprise the steps 120 and 130.

According to this embodiment, the method further comprises the basic step 260. Within this step, the demodulation reference signal (DMRS) is selected in a special manner, namely to guarantee the discrete orthogonal code repetition in frequency over the bandwidth. This helps to improve the detection probability of collisions. This step may, for example, have the sub-step of repeating orthogonal subsequences to form the entire DMRS of the user. Additionally or alternatively, the lengths of the orthogonal subsequence is such that within each part of a DMRS collision (the full collision or partial collision) the colliding sequence sections remain orthogonal or nearly orthogonal. The preferred variant is to select the DMRS based on a Zadoff-Chu code sequence or any different pseudo random sequence. This can be done element wise multiplied with the orthogonal/nearly orthogonal sequence.

Below, embodiments of the present invention or especially features belonging to embodiments of the present invention will be discussed with respect to Fig. 3 and following. Before discussing details, the technical problem will be described from another point of view.

It is stated in new radio (NR) in the 3GPP (NR in 3GPP also refers to in technical context as 5G) that grant free transmission will solve the latency problem. However, this comes on the expense of the reliability, as the transmission will suffer from collision. Another problem arises in this case is: the missed-detection or fa!se-alarm, which will happen due to collision. Our Invention report proposes a solution to limit the collision possibilities (or confine collision) and enhance the detection capability based on the proposed enhancements.

One solution for the aforementioned problem is the method 100 as has been discussed in context with Fig. 1. Below, further aspects for this discrete adaptive sub-channel grant free transmission will be discussed. According to one embodiment, an adaptive scheme which is mainly targeting the following is proposed:

Embodiment 1 : subdivide the the GF RBs/bandwidth into subchannels, which each UE has to choose one of them to transmit its GF data. As a result, all UEs have to transmit starting from discrete RBs. This could be done by informing the UEs the allowed number of sub-channels RBs to use in transmission. Then, each UE divides the configured bandwidth by the number of allowed RBs to transmit to know the total number of sub-bands as shown in Fig. 1.

Embodiment 2: the base-station sends for each UE its Logical Transmission Counter (LTC). The UE uses this LTC to know which sub-channel it would use -if there were something to send at that time instance- to transmit the data. The GF configuration is periodic, so with each Transmission Opportunity (TO) the UE increments its LTC and calculates the corresponding sub-channel id/number it shall send on. The relation between the sub-channel and the LTC is designed to achieve a lowest collision probability for each UE such that the collision doesn’t exceed the maximum utilization ratio, assuming they have the same arrival rate of packets. The computed index from the LTC shall achieve the same collision probability for all UEs if they would transmit the same number of PRBs.

Another solution which matches to the solution that is discussed above is the so-called sub-channel subdivision/sub-channel division deployment which will be discussed with respect to Fig. 3a and 3b.

As in Fig. 3a, assume that the GF RBs are 20 RBs starting from RB 1 until RB 20 and that each UE is allowed to transmit using 5 RBs. In this example, each UE can choose randomly the starting PRB of its sub-channel, in this case from this PRB number set {1 , 6, 1 1 , 16}. This discretization in frequency leads to a lower full collision probability and simplifies the process of blind decoding at the receiver side. Here full collision means a complete collision on the total bandwidth. Note, if not a full collision, then, for example, let us consider 2 PRB as the allocation size. Then we have 10 subbands. If there are 2 users, collision occur with probabaility 107100=0.1. All of these are full collision. If it is 5 PRBs per allocation, collision prob is 4/16 = 0.25. Obviously, the more the potential starting points, the less the chance that two users will select the same position.

Fig. 3a shows one variant of discrete channelization for Grant-Free transmission and preconfigured resources. The total bandwidth W (= 20 PRBs in the example) is divided into L sub-channels. In this case, it is enough to signal the bandwidth W and the sub-channel size in PRBs, i.e., LCH. Another option is to identify the starting PRB, the end PRB (of one sub-channel) and the total bandwidth W. Also it might be enough to signal the W and L (the total number of sub-channels). Other combinations are also possible.

Fig. 3b shows another variant of the sub-channel definition, where some of physical resource blocks (PRBs) groups are non-contiguous and mapped (virtually) to contiguous virtual resource blocks (vRBs) locations. Each group should be with a minimum length, greater than or equal, the minimum DMRS length, e.g., in LTE it is 3 PRBs. The mapping function can be preconfigured or signaled to the UE. Once the UE computes the number of sub-channels L and start and the end of each subchannel (of the total L sub-channels), i.e., PRB_start and PRB_end, the UE knows start of each possible transmission.

From the previous values plus a signal UE ID or a Logical Transmission Counter (LTC) (signaled specifically to each UE or preconfigured to the UE), the UE can compute in each transmission occasion (TO) slot index or repetition (assuming K-repetition) slot index a usable sub-channels to start with. Our invention proposes to compute the position of the sub-channels to be used by every UE such that:

- The collision is minimized to the maximum utilization (overload) factor bi =

#UEs

#Sub-channels

- The sub-channel with collision can be predicted at the base-station

- The collided resources can be confided in a certain band (or hopped band/pattern) If the overload factor < 2, it is always guaranteed to have collision free subchannels (as if they are allocated by grant-base) and collision based sub-channels.

If the UE wants to span more than a single Sub-channel, more consecutive sub-channels are supported to make it easy for the base-station to detect. The UE can compute similarly where to insert the extra transmission sub-channels. It is assumed that the receiver does not control how many sub-channels the UE (transmitter) shall consume in each transmission opportunity. If consecutive sub-channels are assumed, then:

- Option 1 : the UE can select the indices above or under the computed transmission sub-channel index ½(TO)

Option 2: the UE can select the indices either only above or only under the computed transmission sub-channel index i _n (TO)

Note, the step for computing i _n (TO) could be the same for every UE (in our example in the next part, it will be always 1 sub-channel); it can be also different/random for every UE (Set by the BS or pre-configured by the network).

Either option 1 or 2 are selected by the UE to preserve consecutive sub-channels (where the sub-channel may have consecutive PRBs or non-consecutive PRBs bundled together and mapped to consecutive vRBs) at each transmission opportunity. For each overloading factor b ₎ « 2, and multiple UEs spans more sub-channel, partial collision is supported.

According to further embodiments, a so-cai!ed logical transmission counter (LTC) can be used. This helps to compute the starting transmission sub-channel index ½(TO), guaranteeing minimum full-collision, i.e., to the utilization/overload factor br Equations can be computed simultaneously at the transmitters and the receiver.

According to further embodiments, a formulation of a channel counter can be done as follows. The following parameters are assumed.

- N number of UEs

- W total number of GF PRBs

- M sub-band size

- L number of sub-bands

- bi overloading/ factor

- L ₀ overloaded sub-channels

- LTC _j (to) UE i group counter at TO

- TO transmission occasion

- i _n ( TO) sub-channel index (in frequency/starting positions) refers to a

transmission occasion (TO) to

In our proposed scheme, the eNB sends to each UE i: M, p _j , and LTC _j (O) At the eNB side, Pi (overloading factor) is calculated as follows:

Pi = N/L (1 )

At each TO, first, the UE calculates L (sub-channels) as follows:

L = W/M (2)

Second, it calculates L ₀ (overloaded sub-channels) as follows:

L ₀ = L(Pi - 1) * L + 0.5J (3) Third, it calculates LT CTO) as follows:

LTCi(TO) = (LTCJCTO - 1) + 1)%(L + L ₀ ) (4)

Finally, at each TO the following calculates i _n :

i rr = i LT (TO), LTC((TO) < L

(5) n ^{l J} l(LTC _f (TO) - L ₀ )%L, LTCi(TO) > L Note that the rotation of the UE by only one sub-channel can be also different/random rotation for every UE identified by the Base-station of the network.

Different variants/examples of the sub-channel division will be discussed below. These are examples are focused to compute the starting transmission sub-channel index i _n (TO). In the first three examples, we specify multiple options with different overloading factor (i.e., number of UEs to the number of the available sub-channels). Some examples (Figure 4a and 4b) have localized collision band(s) e.g., the end of the transmission band W. Some other examples have a rotating (hopped) collision position(s), e.g., Figs. 4c, 4d, and 5.

Figs. 4d and 5 show the case when one or more UEs uses more than a single subchannel. Both demonstrate partial collision (clearer in Fig. 5, when some overloading UEs stops their transmission).

Assume the following scenario:

- N = 7

- R = 25

- M = 5

- L = 5 b _! = 1.4 (in the example, we have 5 sub-channels, where 2 can be overloaded)

Example 1 - moderate overloading factor with localized collision: In Fig. 4a, i _n (subchannel index (in frequency/starting positions)) is calculated and illustrated for all UEs at different TOs.

As shown in Fig. 4a, using a local counter for each UE LTC leads to distributing the resources fairly among UEs. In the previous example, each UE transmits in a shared subband 57% of its total new transmission attempts, and 43% in a dedicated sub-band. In addition to reducing collision probability, the eNB at each TO knows which UEs are potentially expected to transmit in which sub-band. In this case, the blind decoding at the eNB reduces significantly. Using lower loading factor b _] reduces even more the collision probability as shown in Fig. 4b. Example 2 - low overloading factor with localized collision: Assuming the configuration in Fig. 4b, each UE transmits in a shared sub-band 33.3% of its total new transmission attempts, and 66.7% in a dedicated sub-band. This is computed over time and frequency. This example is illustrated by Fig. 4b.

Example 3 - low overloading factor with rotating collision: Another variant of the design is to rotate collided sub-channels over the different band sub-channels, cf. Fig. 4c. In this case, each UE transmits in a shared sub-band 33.3% of its total new transmission attempts, and 66.7% in a dedicated sub-band. This is computed over time and frequency.

Example 4 - low overloading factor with one UE extending its transmission band. This example is illustrated by Fig. 4d.

Example 5 - low overloading factor with two UEs extending their transmission bands. This example is illustrated by Fig. 5. In this case, each of the UEs (UE0 and UE3) will have possibly partial collided sub-channels. For the receiver to be able to detect partially collided UEs. The transmission may be also design to guarantee partially collided UEs.

Another variant of the design is to rotate collided sub-channels over the different band sub-channels. In this case, each UE transmits in a shared sub-band 33.3% of its total new transmission attempts, and 66.7% in a dedicated sub-band. This is computed over time and frequency.

According to further embodiments, the DMRS is selected to guarantee a discrete orthogonal code repetition frequency over the total allocated band. According to another embodiment, additionally a NOMA scheme can be used to identify the advanced receivers where they decode successive interference allocation. Starting from this embodiment, the DMRS designed for partially collided UE bands can be used.

Depending on the number of PRBs configured for the transmission and the restricted/allowed starting PRBs of the allocation, the UE collision/overlapping, if happens, can only be multiples of PRBs. The set of values of the possible overlap depends on the allowed starting PRBs and the number of PRBs in the allocation. In such situation, the DMRS codes has to be designed to improve the detection probability in such situations. The first solution may result in partial overlapping/collision between UEs and belongs to the category with a restricted starting PRBs of the allocation. The proposed design for DMRS involves repeating orthogonal subsequences to form the entire DMRS of the user. The length of the orthogonal subsequences is such that within each part of a DMRS collision, whether full or partial, the colliding sequence sections remain orthogonal or nearly orthogonal. In this case, a maximum probability of detection is guaranteed as the collided sub-channels have the same DMRS short block. Furthermore, the length of the orthogonal subsequences can also be adjusted to improve the detection probability in frequency-selective channels.

Since the minimum transmission bandwidth is a single sub-channel, i.e. , the UE collision/overlapping domain, it is mandatory to select the sub-channel length (the LCH) to be a positive integer multiple of the orthogonal subsequence length which is also the minimum DMRS length, (e.g., in LTE it is 3 PRBs and in NR it is 1 , 2, 3 or more PRBs). If collision happens, it can only be a multiple of sub-channels, where the sub-channels of different UEs are using orthogonal (or quasi-orthogonal) DMRS sequences. The following is a more description for the short-orthogonal DMRS extensions for partial UE collision.

Especially for the DMRS selection, a design for guaranteeing a fully collided sub-channel based transmission can be used.

In the following, it is proposed how to design a sub-channel based DMRS (i.e., with a DMRS code of the length of a single sub-channel). The DMRS can be based on Zadoff- Chu (ZC) code sequence or any different Pseudorandom (PN) sequence, element-wise multiplied with orthogonal sequences or sequences that are nearly-orthogonal.

In an embodiment, and as in Fig. 6a, the DMRS for each user is designed with the length of a sub-channel LCH, where LCH is selected to be a positive integer multiple of the minimum DMRS length (the length that supports orthogonal codes, this also includes the multi-cell design). The DMRS in each sub-channel for each UE should be configured similarly on a consistent OFDM symbol position.

If the UE decides it would transmit on more than a single sub-channel, two DMRS code sequence shall be selected, i.e., Ci and Ci’. In one embodiment the selection of Ci, Ci”, .... Ci” ^(k) , where k is the maximum number of allocated sub-channel for user, is based on the following: - It might be supported to have Ci = Ci”= ... = Ci” ^(k) , i.e., DMRS repetition per subchannel

- It might be supported to have Ci = cyclic_shift(Ci’), and Ci’ = cyclic_shift(Ci”), and so on

- It might be supported that Ci, Ci”, .... Ci” ^(k) could be selected from different bases

In one embodiment, Ci and Cj (where I and j are two different users allocated to the same sub-channel, within the same grant-free band) shall be selected from:

- Orthogonal bases (e.g., if ZC is used, a cyclic shift may be configured differently for each user)

- Quasi-orthogonal bases (e.g., with a very low correlation properties)

In the Fig.6b, it is assumed that two DMRS positions are configured for each UE in the grant-free configuration, i.e., exact OFDM symbol position. Each equivalent DMRS sequence, e.g., Ci1 and Cj1 or Ci2 and Cj2 are selected such that:

- Orthogonal bases (e.g., if a ZC sequence is used, a cyclic shift may be configured differently for each user)

- Quasi-orthogonal bases (e.g., with a very low correlation properties)

Similar to the previous example, the selection of Ci1 , Ci1”, .... Ci1” ^(k) , or the selection of Ci2, Ci2”, .... Ci2” ^(k) , is based on the following:

It might be supported to have Cit = Cit”= ... = Cit” ^(k) , i.e., DMRS repletion per subchannel, where t is either 1 or 2 in our example

It might be supported to have Cit = cyclic_shift(Cit’), and Cit’ = cyclic_shift(Cit”), and so on

- It might be supported that Cit, Cit”, ... , Cit” ^(k) could be selected from different bases

The below discussed design for identifying colliding sub-channels/UEs for a NOMA are especially used in combination with the DMRS selection in the NOMA scheme. The DMRS selection can be used as a locator of colliding UEs, i.e., after detecting the colliding short/discrete DMRS code in each sub-channel; hence, partially colliding non-orthogonal multiple access users will be much easier. In this case, the following should be consider: a short/discrete DMRS design similar to one of the previous embodiment should be used to enhance the detection quality on every sub-channel

Hence, the receiver detect each and every colliding/transmitting UE on each subchannel

Once the receiver knows all the contributing UEs on each sub-channel, it start applying successive interference cancelation (SIC) receiver differently on each subchannel, i.e., based on the collision detection results (refer to Fig. 6c).

Hence, sub-channels with no collision, can be used without SIC receivers. Also received values in these sub-channels can be used to enhance detection on the collided ones

In the example in Fig. 6c, once the short/discrete DMRS design succeeds to locate colliding UEs, the detector will only apply a SIC receiver at those sub-channels detected with more than a single UE, e.g., the two middle sub-channels in Fig. 6c. Other noncolliding sub-channels are detected with less computational effort.

Hence, in one embodiment, it is proposed to design a NOMA with a partial collision using a short/discrete DMRS design with a dedicated Sub-channels as in another basic embodiment. This DMRS design used to enhance the receiving capabilities.

Regarding the above discussed embodiments, a modulation coding scheme and transport block size adaption can be used for expanding sub-channel transmission.

As mentioned previously, the base-station or the network (represented by the RRC or other layers) signals a constant MCS and/or a TBS (related to the number of PRBs in a sub-channel L _C H) value (equally or different) to every UE sharing the GF grant.

In order to allow the UEs to adapt their initial/pre-configured MCS and/or TBS according to the different channel conditions (if they suffer from bad channel conditions, i.e., related to Downlink reference signal) or requiring more reliability, or requiring more data rate, another combination of MCS-Regions can be used.

In an embodiment A, once this initial/pre-configured MCS and/or TBS are signaled, it is up to the UE to perform one of the following: - A UE may preserve the initial/pre-configured MCS and/or TBS if it is allocated to one or more sub-channels, i.e. , when requiring more data (same MCS over multiple sub-channels and higher TBS)

- A UE may reduce the initial/pre-configured MCS and/or TBS as when the UE

allocates more than one sub-channels, i.e,,

o MCS for 1 sub-channel > MCS for 2 sub-channels > ... > MCS for k subchannels

o The UE can reduced the MCS based on the existing 3GPP tables or new formula

Note: in this case, TBS size is different or similar to the initial/pre-configured one.

The TBS can be computed by the UE given by the TBSJndex and number PRBs for each modulation coding scheme, i.e., using the TBS tables of the right dimension.

In another embodiment B, a UE may use an auxiliary table (e.g. for different strength) to identify an adaptive MCS based on the channel conditions. Different tables may be configured to different initial/pre-configured MCS by base-station or the network, e.g., Table 1 has Table X for the configuration stated.

The channel conditions shall be adapted based on the measured downlink reference measurements, i.e., assuming a sufficient reciprocity or correlation between UL and DL channel (or even between different sidelink channels (UE-2-UE channel, if the receiver is another UE). Hence, a table may be invented to allocate, for example, High MCS for higher sub-channel indices, and lower MCS for lower sub-channel indices. Hence, once the UE send on a sub-channel, the UE may use either:

- The MCS of the nominated sub-channel index (table x). Yet, if the UE uses more than a sub-channel, the UE uses, for example, only the minimum MCS (of the highest sub-channel index).

- The reference MCS signaled by the base-station or the network

The TBS can be computed by the UE given by the TBSJndex and number PRBs for each modulation coding scheme, i.e., using the TBS tables of the right dimension. The base-station, shall trigger either the method in embodiment X or embodiment Y. In each case, and based on the detected allocated sub-channels, the base-station shall decode first using the computed MCS at the UE and if not decode, then the referenced (signaled) MCS by the base-station or network.

Another approach will be discussed with respect to Fig. 7. Fig. 7 shows an adaptive modulation coding scheme selected for configured grants. According to this embodiment, it is possible (based on the table as exemplarily shown by Fig. 7) that the UE selects the position of the subchannel based on the received power strength (or other channel measurements) from the previous transmitted signal to the intended UE. In this case, also UE with weak reception (e.g., cell edge UEs) will be selecting sub-channels with low MCS. This can also be used by the receiver (e.g., base-station) to identify UE positions and signal quality.

Another embodiment enables the dividing of the configured resources into different resources, to be described/clarified with either:

• the configured grant resources or a resource-pool are resources of multiple configured grants (configured simultaneously active), where each configured grant resource is composed of 1 or multiple subchannels. This is true as our figures comprises multiple configured grants for resource allocation type 1 and one figure discusses type 0 with vRBs.

• the configured grant resources are a some of resources similar to a resource pool split into multiple subchannels. The periodicity of the configured grants may be described as a set of bit-maps in time domain, i.e., similar to the resource pool.

According to embodiments, each resource pool is split into multiple resources

⁸ V2V communication (or a vehicular sidelink communication) and its need for

DMRS PSCCH discovery, where a UE in a V2V pair or in a V2X context is a vehicular UE.

• D2D communication (or a sidelink communication) and its need for DMRS PSCCH discovery, where a UE in a D2D pair or in sidelink context can be a mobile device.

UEs allocate different number of subchannels based on traffic

UEs allocate 1 , 2, 3,4 + symbols as DMRS based on relative speed. UEs allocate resources with DMRS, which (the DMRS) identified bases on the subchannel size (subchannel specific), the specific UEs ID (UE specific), resource pool/configured grant specific, or geographical zone specific

The above discussed embodiments are directed to managing grant free resources. This can also be applied to other resources, e.g., configured grants.

Configured grants are resources’ time and/or frequency portions which are dedicated by the base station for a UE. With respect to Fig. 1a, the configured grants can be a portion of all sub-channels/multiple sub-channels or even all sub-channels. Each configured grant can differ from each other with regard to the number of blocks and with regard to its size. So-called active configured grants are resources which can be freely selected by UE. This means that the UE can choose one of the configured grants, multiple of the configured grants or all of the configured grants. A configured resource pool comprises predetermined sub-channels (variable number of blocks) which are dedicated, such that a UE can use them.

Therefore, according to alternative wording, according to a new wording, the grant free resources may also be referred to as configured grant resources which may be comprises resources of multiple configured grants or may be or may comprise resources similar to a rescue pool split into multiple subchannels.

Starting from this, further embodiments may be described as follows.

The configured grant resources can be divided into different resources (sub-channels).

According to further embodiments, the configured grant resources (divided into different resources) are resources of multiple configured resources (configured simultaneously), where each division of resources is composed of one or multiple sub-channels.

Note, according to further embodiments, the configured resources (divided into different resources) are a sum of resources similar to a resource pool or configured-grants split into multiple sub-channels. The periodicity of the configured grants may be described as a set of bit-maps in time domain, i.e., similar to the resource pool. According to further embodiments, the DMRS of each subchannel/resource division is designed based on the subchannel length to guarantee maximum correlation properties. DMRS selection is used to enhance discovery of transmitting nodes.

According to further embodiments, DMRS can be identified per user equipment (UE), per- subchannel size, per-geographical zone, or per resource pool/configured resources

The above discussed approaches are applicable to the following technical fields but are not limited to these:

V2X, D2D, mMTC, URLLC, critical communication, NOMA, NR-Unlicensed

Regarding V2X it should be mentioned that there are a plurality of additional use cases, for example RRC configured“resources” in a form of a resource pool (with start RB, offset, and bitmap).

Although some aspects have been described in the context of an apparatus, it is clear that these aspects also represent a description of the corresponding method, where a block or device corresponds to a method step or a feature of a method step. Analogously, aspects described in the context of a method step also represent a description of a corresponding block or item or feature of a corresponding apparatus. Some or all of the method steps may be executed by (or using) a hardware apparatus, like for example, a microprocessor, a programmable computer or an electronic circuit. In some embodiments, some one or more of the most important method steps may be executed by such an apparatus.

Depending on certain implementation requirements, embodiments of the invention can be implemented in hardware or in software. The implementation can be performed using a digital storage medium, for example a floppy disk, a DVD, a Bfu-Ray, a CD, a ROM, a PROM, an EPROM, an EEPROM or a FLASH memory, having electronically readable control signals stored thereon, which cooperate (or are capable of cooperating) with a programmable computer system such that the respective method is performed. Therefore, the digital storage medium may be computer readable.

Some embodiments according to the invention comprise a data carrier having electronically readable control signals, which are capable of cooperating with a programmable computer system, such that one of the methods described herein is performed.

Generally, embodiments of the present invention can be implemented as a computer program product with a program code, the program code being operative for performing one of the methods when the computer program product runs on a computer. The program code may for example be stored on a machine readable carrier.

Other embodiments comprise the computer program for performing one of the methods described herein, stored on a machine readable carrier.

In other words, an embodiment of the inventive method is, therefore, a computer program having a program code for performing one of the methods described herein, when the computer program runs on a computer.

A further embodiment of the inventive methods is, therefore, a data carrier (or a digital storage medium, or a computer-readable medium) comprising, recorded thereon, the computer program for performing one of the methods described herein. The data carrier, the digital storage medium or the recorded medium are typically tangible and/or nontransitionary.

A further embodiment of the inventive method is, therefore, a data stream or a sequence of signals representing the computer program for performing one of the methods described herein. The data stream or the sequence of signals may for example be configured to be transferred via a data communication connection, for example via the Internet.

A further embodiment comprises a processing means, for example a computer, or a programmable logic device, configured to or adapted to perform one of the methods described herein.

A further embodiment comprises a computer having installed thereon the computer program for performing one of the methods described herein.

A further embodiment according to the invention comprises an apparatus or a system configured to transfer (for example, electronically or optically) a computer program for performing one of the methods described herein to a receiver. The receiver may, for example, be a computer, a mobile device, a memory device or the like. The apparatus or system may, for example, comprise a file server for transferring the computer program to the receiver .

In some embodiments, a programmable logic device (for example a field programmable gate array) may be used to perform some or all of the functionalities of the methods described herein. In some embodiments, a field programmable gate array may cooperate with a microprocessor in order to perform one of the methods described herein. Generally, the methods are preferably performed by any hardware apparatus.

The above described embodiments are merely illustrative for the principles of the present invention. It is understood that modifications and variations of the arrangements and the details described herein will be apparent to others skilled in the art. It is the intent, therefore, to be limited only by the scope of the impending patent claims and not by the specific details presented by way of description and explanation of the embodiments herein.

Reference Label

[1] TS38.213 Evolved Universal Terrestrial Radio Access (E-UTRA);

Physical layer procedures; V14.5.0

[2] TS 38,331 Evolved Universal Terrestrial Radio Access (E-UTRA) - Radio Resource Control (RRC); V14, [3] 3GPP TS 38.211 Evolved Universal Terrestrial Radio Access (E-UTRA);

Physical Channels and Modulation, v 14.3.0

[4] 3GPP TS 38.212 Evolved Universal Terrestrial Radio Access (E-UTRA);

Multiplexing and channel coding, v 14.3.0

[5] 3GPP TS 38.321 Evolved Universal Terrestrial Radio Access (E-UTRA);

Medium Access Control (MAC) protocol specification, v 14.3.0

[6] 2017P59629 EP: Emergency Notification (URLLC) Requesting Spontaneous Grant Free Transmission for V2X

Abbreviation Meaning

BS Base Station

CBR Channel Busy Ratio

D2D Device-to-Device

EN Emergency Notification

eNB Evolved Node B (base station)

FDM Frequency Division Multiplexing

LTE Long-Term Evolution

Interface using the Sidelink Channel

for D2D communication

PPPP ProSe per packet priority

PRB Physical Resource Block

ProSe Proximity Services

RA Resource Allocation

SCI Sidelink Control Information

SL sidelink

sTTI Short Transmission Time Interval

TDM Time Division Multiplexing TDMA Time Division Multiple Access

UE User Entity (User Terminal)

Ultra-Reliable Low-Latency

URLLC

Communication

Vehicle-to-vehicle, as a sidelink

V2V

communication

V2I Vehicle-to-infrastructure

V2P Vehicle-to-pedestrian

V2N Vehicle-to-network

Vehicle-to-everything, i.e., V2V, V2I,

V2X

V2P, V2N