Patent Description:
From the analogue technique to the Long Term Evolution (LTE), each generation of mobile technology has been motivated by a need to address challenges which are not overcome by its predecessor. The <NUM>th generation (<NUM>) of mobile technology focuses on demands and businesses beyond the LTE. It is expected to obtain a fully mobile and connected society related to a tremendous growth in connectivity and density/volume of traffic that may be required in the near future.

A Physical Downlink Control Channel (PDCCH) may carry a message called Downlink Control Information (DCI) which may include resource assignment for a User Equipment (UE) or a group of UEs. A base station may transmit a plurality of DCIs or PDCCHs in one subframe. It may need to transmit a great amount of parameters to the UE for its operation, but there may be cases in which some information is not required for a particular UE.

In the 4th generation (<NUM>) LTE, the PDCCH may use resources present in first nOFDM symbols, where n is given in a Physical Control Format Indicator Channel (PCFICH). A Control Channel Element (CCE)index may be used to refer to a CCE number at which control channel data (PDCCH) is allocated. Normally this index may change for each subframe, meaning that even the same PDCCH data (e. g, a PDCCH for the same UE) allocated in each subframe may change subframe by subframe. The CCE index may be decided by an eNB according to the following formula: <MAT> where Y-<NUM> = nRNTI ≠ <NUM>, which is determined by a Radio Network Temporary Identity (RNTI) assigned to each UE, where L denotes the aggregation level; Yk = (A·Yk-<NUM>)modD, wherein A = <NUM> and D = <NUM>; m = <NUM>,···,M(L) -<NUM>, wherein M(L) is the number of PDCCH candidates to monitor in a given search space, NCCE,k denotes the CCE number in subframe k, and i = <NUM>,. , L-<NUM>, as described in 3GPP <NUM> V12. <NUM><NUM>.

In the <NUM> New Radio (NR), a similar formula below may be used to determine the CCE index: <MAT>.

However, the <NUM>rd Generation Partner Project (3GPP) does not define a specific manner to assign RNTIs to UEs. Thus, RNTIs may somehow be randomly assigned to UEs. Then, CCE conflicts may occur. This means that either more OFDM symbols must be used to accommodate CCE requests by the UEs or even some UE downlink or uplink transmissions have to be declined due to unavailable CCE resources.

Furthermore, as the CCE conflicts occur frequently, it implies that a CCE part assigned to one UE may not be the one starting from the first CCE of a search space. Then, the UE has to search more CCEs for blind PDCCH detection. This may not be friendly for power saving or processing timing.

<CIT> seems to disclose a method to avoid collisions on the Physical Downlink Control Channel (PDCCH) used e.g. by a macro cell and at least one low-power cell.

<CIT> seems to disclose method of decoding downlink control information that was encoded using polar encoding <NPL> seems to disclose various search space allocation scheme to reduce the blocking probability.

<CIT> seems to disclose a method for allocation of GC-RNTIs to UEs for group communication to enable efficient communication management within each group.

Furthermore, the embodiments of the invention are those defined by the claims. Moreover, examples and embodiments, which are not covered by the claims are presented not as embodiments of the invention, but as background art or examples useful for understanding the invention.

It is an object of the present disclosure to propose an RNTI assignment method and apparatus for either employing a static list of RNTIs for a limited number of UEs, or strategically assigning RNTIs to UEs. With the present disclosure, in both NR and LTE environments, a gNB or an eNB can allocate the PDCCH for one UE, starting from the first CCE within its search space.

According to a first aspect of the present disclosure, a method implemented by a network node in a communication network is provided. The method comprises: assigning a radio network temporary identity (RNTI) comprised in one of a first number of groups corresponding to an aggregation level to a user equipment (UE) associated with the one group; wherein for the first number of UEs, different UEs are associated with different groups corresponding to different control channel elements (CCEs).

In an alternative embodiment of the first aspect, the method may further comprise: assigning one or more CCEs to the UE according to the RNTI assigned to the UE.

In an alternative embodiment of the first aspect, the method may further comprise: assigning one or more CCEs corresponding to the one group comprising the RNTI.

In a further alternative embodiment of the first aspect, the UE may be associated with the group among the first number of groups by sequence.

According to a second aspect of the present disclosure, a network node in a communication network is provided. The network node comprises a processor and a memory communicatively coupled to the processor and adapted to store instructions. When the instructions are executed by the processor, the instructions cause the network node to perform operations of the method according to the above first aspect.

According to a third aspect of the present disclosure, a non-transitory computer readable medium having a computer program stored thereon is provided. When the computer program is executed by a set of one or more processors of a network node in a communication network, the computer program causes the network node to perform operations of the method according to the above first aspect.

In the present disclosure, the number of OFDM symbols used for the PDCCH can be reduced, thereby increasing cell throughout since less PDCCH resource implies more PDSCH resources, and decreasing PDCCH blind detection duration and UE power consumption.

The present disclosure may be best understood by way of example with reference to the following description and accompanying drawings that are used to illustrate embodiments of the present disclosure. In the drawings:.

The following detailed description describes a method and apparatus for resource assignment. In the following detailed description, numerous specific details such as logic implementations, types and interrelationships of system components, etc. are set forth in order to provide a more thorough understanding of the present disclosure. It should be appreciated, however, by one skilled in the art that the present disclosure may be practiced without such specific details. In other instances, control structures, circuits and instruction sequences have not been shown in detail in order not to obscure the present disclosure. Those of ordinary skill in the art, with the included descriptions, will be able to implement appropriate functionality without undue experimentation.

References in the specification to "one embodiment", "an embodiment", "an example embodiment" etc. indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic.

Bracketed texts and blocks with dashed borders (e.g., large dashes, small dashes, dot-dash, and dots) may be used herein to illustrate optional operations that add additional features to embodiments of the present disclosure. However, such notation should not be taken to mean that these are the only options or optional operations, and/or that blocks with solid borders are not optional in certain embodiments of the present disclosure.

In the following detailed description and claims, the terms "coupled" and "connected", along with their derivatives, may be used. "Coupled" is used to indicate that two or more elements, which may or may not be in direct physical or electrical contact with each other, cooperate or interact with each other.

An electronic device stores and transmits (internally and/or with other electronic devices) code (which is composed of software instructions and which is sometimes referred to as computer program code or a computer program) and/or data using machine-readable media (also called computer-readable media), such as machine-readable storage media (e.g., magnetic disks, optical disks, read only memory (ROM), flash memory devices, phase change memory) and machine-readable transmission media (also called a carrier) (e.g., electrical, optical, radio, acoustical or other forms of propagated signals - such as carrier waves, infrared signals). Thus, an electronic device (e.g., a computer) includes hardware and software, such as a set of one or more processors coupled to one or more machine-readable storage media to store code for execution on the set of processors and/or to store data. For instance, an electronic device may include non-volatile memory containing the code since the non-volatile memory can persist code/data even when the electronic device is turned off (when power is removed), and while the electronic device is turned on, that part of the code that is to be executed by the processor(s) of that electronic device is typically copied from the slower non-volatile memory into volatile memory (e.g., dynamic random access memory (DRAM), static random access memory (SRAM)) of that electronic device. Typical electronic devices also include a set of one or more physical interfaces to establish connections (to transmit and/or receive code and/or data using propagating signals) with other electronic devices. One or more parts of an embodiment of the present disclosure may be implemented using different combinations of software, firmware, and/or hardware.

In order to demo a peak throughput of an NR or LTE cell, a downlink throughput may be expected to be as high as possible when all UEs attached to a cell have good channel quality. Therefore, a gNB or an eNB may store a static or semi-static list of RNTIs, which may be externally configured. When a UE is attached to the cell, one of the RNTIs may be assigned to this UE for data transmission. This list of RNTIs is designed such that CCE conflicts can be minimized or be completely avoided.

An example of such a static list of Cell Radio Network Temporary Identities (C-RNTIs) in the LTE is shown in Table I below. When an aggregation level (AL) equals to <NUM> for all the UEs, there is no CCE conflict. In an example, Table I below may be generated by exhaustive search.

In Table I, the first two columns may represent UE serial numbers and their corresponding C-RNTIs respectively. The rest of the columns may represent CCEs associated with subframes <NUM>~<NUM>, wherein the CCEs associated with subframe <NUM> and subframe <NUM> are divided into CCEs for downlink assignment and for uplink grant. As illustrated in Table I, AL = <NUM>, but it is not limited thereto, i.e., AL may also equal to <NUM>, <NUM>, <NUM>, <NUM>.

During formation of the table, taking subframe <NUM> as an example, a CCE may be calculated from a corresponding C-RNTI for a UE, e.g., for UE No. <NUM>, the CCE of <NUM> may be calculated from the C-RNTI of <NUM>. In an example, a plurality of CCEs may be calculated from one C-RNTI, and a predetermined number of CCEs may be selected from the plurality of CCEs, e.g., the leading CCEs may be selected. In Table I, since AL = <NUM>, the predetermined number may equal to <NUM>. If AL = <NUM>, the predetermined number may equal to <NUM>, and so forth.

For the same subframe, i.e., the same column of the table, a CCE conflict may occur. For example, assuming that the CCE corresponding to UE No. <NUM> is calculated from the C-RNTI (<NUM>) also as <NUM>, then another CCE calculated from this C-RNTI but different from any previous CCEs in the list may be reselected, e.g., <NUM> for UE No. <NUM>. Finally, the UE serial number, the C-RNTI and the updated CCE may form mapping relationship for the current subframe <NUM>.

The CCEs for subsequent subframes may be processed as described above to eliminate or at least reduce the conflicts. This may be applicable to all of the subsequent subframes.

In the case that there are a limited number of UEs, the static or semi-static table may be useful. However, if a large number of UEs are attached to the cell, an approach for reducing possibility of the CCE conflicts may be utilized.

Table II below illustrates an approach for grouping all available C-RNTIs. The C-RNTIs may range e.g. from <NUM> to <NUM>, and what are listed below is only part of <NUM> to <NUM>, i.e., <NUM>-<NUM> which are different from each other as an example in Table II. It should be noted that although the C-RNTIs are shown in sequence from <NUM> to <NUM> in Table II, each position within any group may contain any one of <NUM>-<NUM> as long as all of the values <NUM>-<NUM> are distributed over these <NUM> positions in Table II. All of the available C-NRTIs may be divided into a number of groups corresponding to the aggregation level, e.g., <NUM> groups when AL = <NUM>; <NUM> groups when AL = <NUM>; and <NUM> group when AL = <NUM>. That is, the number is corresponding to the aggregation level. Moreover, the number of CCEs required for each group may also be corresponding to the aggregation level, e.g., when AL = <NUM>, the number of CCEs required may be <NUM>; when AL = <NUM>, the number of CCEs required may be <NUM>; and when AL = <NUM>, the number of CCEs required may be <NUM>.

When the m-th (m = <NUM>, <NUM>, <NUM>,. ) UE is attached to the cell at the aggregation level l, this UE may be arranged for the group [m mod Nl], where Nl denotes the number of groups corresponding to the aggregation level l. That is to say, a new UE may be arranged for the next group sequentially. Then, a C-RNTI may be randomly selected from the C-RNTIs comprised in this group. For a plurality of UEs arranged for the same group, the C-RNTIs comprised in this group may be assigned to the UEs randomly or in sequence.

If a group which is to accommodate a new UE at the present aggregation level is not available, e.g., due to line breakdown, then the UE may be mapped to a group at a lower aggregation level. For example, at the aggregation level <NUM>, when a UE is to be arranged for group <NUM> but this group <NUM> is not available, the UE may then be associated with group <NUM> corresponding to the aggregation level <NUM>, and a C-RNTI may be selected from the C-RNTIs comprised in the group <NUM> at the aggregation level <NUM>.

As an example, the UE which is associated with group <NUM> at the aggregation level <NUM> may be preferably assigned with a C-RNTI comprised in the corresponding leading group (i.e., group <NUM>) at the aggregation level.

Moreover, a new UE may be arranged for a group at a higher aggregation level, e.g., disconnected from the present aggregation level. If the number of previous UEs associated with the previous aggregation level is greater than a predetermined threshold, there may not be a respective group at the higher aggregation level. In this case, the UE may then be associated with a group at the previous aggregation level instead, and a C-RNTI may be selected from the C-RNTIs comprised in this group at the previous aggregation level.

The UE serial number, the C-RNTI and the CCE for a certain subframe (e.g., the first subframe) in Table I may be similar to the case in which each of the groups in Table II comprises only one RNTI. As an example, for Table II, the CCEs for the next subframe <NUM> may be predicted from those for subframe <NUM>. This prediction from a previous subframe may be applicable to all of the subsequent subframes.

One or more CCEs may be calculated from the selected C-RNTI for the UE. In an example, a predetermined number of CCEs may be selected from the calculated CCEs, e.g., the leading CCEs may be selected. If any of the selected CCEs is identical to a previous CCE, the CCE may be reselected from the calculated CCEs.

In this way, search spaces for the UE may be misaligned as much as possible so that the leading CCEs in each of the search spaces may be available. Then, blind PDCCH searches may be reduced at the UE side.

<FIG> is a flow chart illustrating a method <NUM> for resource assignment according to some embodiments of the present disclosure. The method <NUM> may be performed in a base station by way of example only but it is not limited thereto.

In one embodiment, the method <NUM> may begin with assigning an RNTI comprised in one of a first number of groups corresponding to an aggregation level to a UE associated with this one group (block <NUM>). At this aggregation level, for the first number of UEs, different UEs may be associated with different groups of RNTIs, and the different groups may be corresponding to different CCEs.

As an optional example, one or more CCEs may be assigned to the UE according to the RNTI assigned to the UE (block <NUM>). As a further example, the one or more CCEs may be calculated from the RNTI. As a still further example, the one or more CCEs may be leading results of the calculation.

As another optional example, one or more CCEs corresponding to this one group which comprises the RNTI may be assigned (block <NUM>).

As a further example, the UE may be associated with the group among the first number of groups by sequence.

In an example, each of the groups may comprise one RNTI. If the first number of groups form a static table, then this group may further comprise one or more CCE corresponding to the RNTI.

In another example, each of the groups may comprise a plurality of RNTIs. The plurality of RNTIs of each group may be assigned to different UEs associated with the group randomly or in sequence.

The RNTI comprised in each group may be related to the CCE corresponding to the group.

As an example, the method <NUM> may be performed with respect to at least a first subframe. The method <NUM> may also extend to each of the subsequent subframes by prediction from its previous subframe.

As an example, the number of CCEs corresponding to each group may equal to the aggregation level, e.g., when AL = <NUM>, the number of CCEs for each group equals to <NUM>.

In an optional example, if a group of the first number of groups corresponding to the aggregation level is not available, the UE may be associated with one of a second number of groups corresponding to a lower aggregation level than the aggregation level.

In an optional example, if the aggregation level is higher than a previous aggregation level associated with previous UEs and the number of previous UEs with the previous aggregation level is larger than a threshold, the UE may be associated with one of a third number of groups corresponding to the previous aggregation level.

<FIG> is a block diagram illustrating a network node <NUM> for resource assignment according to some embodiments of the present disclosure. As an example, the network node <NUM> may be implemented as a base station, but it is not limited thereto. It should be appreciated that the network node <NUM> may be implemented using components other than those illustrated in <FIG>.

With reference to <FIG>, the network node <NUM> may comprise at least a processor <NUM>, a memory <NUM>, an interface <NUM> and a communication medium <NUM>. The processor <NUM>, the memory <NUM> and the interface <NUM> may be communicatively coupled to each other via the communication medium <NUM>.

The processor <NUM> may include one or more processing units. A processing unit may be a physical device or article of manufacture comprising one or more integrated circuits that read data and instructions from computer readable media, such as the memory <NUM>, and selectively execute the instructions. In various embodiments, the processor <NUM> may be implemented in various ways. As an example, the processor <NUM> may be implemented as one or more processing cores. As another example, the processor <NUM> may comprise one or more separate microprocessors. In yet another example, the processor <NUM> may comprise an application-specific integrated circuit (ASIC) that provides specific functionality. In still another example, the processor <NUM> may provide specific functionality by using an ASIC and/or by executing computer-executable instructions.

The memory <NUM> may include one or more computer-usable or computer-readable storage medium capable of storing data and/or computer-executable instructions. It should be appreciated that the storage medium is preferably a non-transitory storage medium.

The interface <NUM> may be a device or article of manufacture that enables the network node <NUM> to send data to or receive data from external devices.

The communication medium <NUM> may facilitate communication among the processor <NUM>, the memory <NUM> and the interface <NUM>. The communication medium <NUM> may be implemented in various ways. For example, the communication medium <NUM> may comprise a Peripheral Component Interconnect (PCI) bus, a PCI Express bus, an accelerated graphics port (AGP) bus, a serial Advanced Technology Attachment (ATA) interconnect, a parallel ATA interconnect, a Fiber Channel interconnect, a USB bus, a Small Computing System Interface (SCSI) interface, or another type of communications medium.

In the example of <FIG>, the instructions stored in the memory <NUM> may include those that, when executed by the processor <NUM>, cause the network node <NUM> to implement the method described with respect to <FIG>.

<FIG> is another block diagram illustrating a network node <NUM> for resource assignment according to some embodiments of the present disclosure. As an example, the network node <NUM> may be implemented as a base station, but it is not limited thereto. It should be appreciated that the network node <NUM> may be implemented using components other than those illustrated in <FIG>.

With reference to <FIG>, the network node <NUM> may comprise at least an RNTI assignment unit <NUM>. The RNTI assignment unit <NUM> may be adapted to perform at least the operation described in the block <NUM> of <FIG>.

As an example, the network node <NUM> may further comprise a CCE assignment unit <NUM>. The CCE assignment unit <NUM> may be adapted to perform at least the operations described in the blocks <NUM>-<NUM> of <FIG>.

Some units are illustrated as separate units in <FIG>. However, this is merely to indicate that the functionality is separated. The units may be provided as separate elements. However, other arrangements are possible, e.g., some of them may be combined as one unit. Any combination of the units may be implemented in any combination of software, hardware, and/or firmware in any suitable location. For example, there may be more controllers configured separately, or just one controller for all of the components.

The units shown in <FIG>may constitute machine-executable instructions embodied within e.g. a machine readable medium, which when executed by a machine will cause the machine to perform the operations described. Besides, any of these units may be implemented as hardware, such as an application specific integrated circuit (ASIC), Digital Signal Processor (DSP), Field Programmable Gate Array (FPGA) or the like.

Moreover, it should be appreciated that the arrangements described herein are set forth only as examples. Other arrangements (e.g., more controllers or more detectors, etc.) may be used in addition to or instead of those shown, and some units may be omitted altogether. Functionality and cooperation of these units are correspondingly described in more detail with reference to <FIG>.

<FIG> is a graph illustrating CCE conflict probabilities vs. UE numbers with respect to different approaches. As shown in <FIG>, in the case of LTE <NUM> at the aggregation level <NUM>, performances for random selection of RNTIs, for selection of RNTIs in a row, and for grouping of RNTIs according to the present disclosure which is shown as the split algorithm are compared. When there are not so many UEs attached in a cell, the grouping approach may reduce CCE conflicts by <NUM>% and <NUM>% as compared to the other two approaches respectively. When there are many UEs attached, the CCE conflicts may be reduced by <NUM>% and <NUM>% respectively.

<FIG> is a block diagram schematically illustrating a telecommunication network connected via an intermediate network to a host computer.

With reference to <FIG>, in accordance with an embodiment, a communication system includes a telecommunication network <NUM>, such as a 3GPP-type cellular network, which comprises an access network <NUM>, such as a radio access network, and a core network <NUM>. The access network <NUM> comprises a plurality of base stations 512a, 512b, 512c, such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 513a, 513b, 513c. Each base station 512a, 512b, 512c is connectable to the core network <NUM> over a wired or wireless connection <NUM>. A first user equipment (UE) <NUM> located in coverage area 513c is configured to wirelessly connect to, or be paged by, the corresponding base station 512c. A second UE <NUM> in coverage area 513a is wirelessly connectable to the corresponding base station 512a.

It is noted that the host computer <NUM>, base station <NUM> and UE <NUM> illustrated in <FIG> may be identical to the host computer <NUM>, one of the base stations 512a, 512b, 512c and one of the UEs <NUM>, <NUM> of <FIG>, respectively.

The wireless connection <NUM> between the UE <NUM> and the base station <NUM> is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to the UE <NUM> using the OTT connection <NUM>, in which the wireless connection <NUM> forms the last segment. More precisely, the teachings of these embodiments may improve the radio resource utilization and thereby provide benefits such as reduced user waiting time.

Some portions of the foregoing detailed description have been presented in terms of algorithms and symbolic representations of transactions on data bits within a computer memory. These algorithmic descriptions and representations are ways used by those skilled in the signal processing arts to most effectively convey the substance of their work to others skilled in the art. An algorithm is here, and generally, conceived to be a self-consistent sequence of transactions leading to a desired result. The transactions are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated.

It should be appreciated, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the above discussion, it is appreciated that throughout the description, discussions utilizing terms such as "processing" or "computing" or "calculating" or "determining" or "displaying" or the like, refer to actions and processes of a computer system, or a similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices.

Various general-purpose systems may be used with programs in accordance with the teachings herein, or it may prove convenient to construct more specialized apparatus to perform the required method transactions. In addition, embodiments of the present disclosure are not described with reference to any particular programming language. It should be appreciated that a variety of programming languages may be used to implement the teachings of embodiments of the present disclosure as described herein.

An embodiment of the present disclosure may be an article of manufacture in which a non-transitory machine-readable medium (such as microelectronic memory) has stored thereon instructions (e.g., computer code) which program one or more signal processing components (generically referred to here as a "processor") to perform the operations described above. In other embodiments, some of these operations might be performed by specific hardware components that contain hardwired logic (e.g., dedicated digital filter blocks and state machines). Those operations might alternatively be performed by any combination of programmed signal processing components and fixed hardwired circuit components.

In the foregoing detailed description, embodiments of the present disclosure have been described with reference to specific exemplary embodiments thereof. It will be evident that various modifications may be made thereto without departing from the scope of the present disclosure as set forth in the following claims. The specification and drawings are, accordingly, to be regarded in an illustrative sense rather than a restrictive sense.

Claim 1:
A method (<NUM>) implemented by a network node in a communication network, comprising:
assigning (<NUM>), to a user equipment, UE, a radio network temporary identity RNTI, comprised in one of a first number of groups of RNTIs, the first number of groups corresponding to an aggregation level, and the UE is associated with the one group;
wherein for the first number of groups of RNTIs, different UEs are associated with different groups corresponding to different control channel elements, CCEs; and
wherein each group comprises multiple RNTIs, and wherein the multiple RNTIs of each group are assigned to different UEs associated with the group randomly or in sequence.