JP6811333B2 - Extended Channel Quality Indicator (CQI) measurement procedure for URLLC - Google Patents

Description

The present invention relates to wireless networks in general, and particularly to channel quality indicators (CQIs) in wireless systems, measurement and reporting procedures, link adaptation (LA), and ultra-high reliability and low latency. It relates to the support of communication (URLLC: ultra-reliable low-latency communications).

background

This section provides the background or context of the invention disclosed below. The description herein may include concepts that may be pursued, but may not necessarily be concepts that were previously conceived, implemented, or described. Therefore, unless expressly stated otherwise in the specification of the present application, the matters described in this section are not prior art for the description of the present application, nor are they recognized as prior art by inclusion in this section. Abbreviations that may be included herein and / or the drawings are defined after the main part of the detailed description section below.

Ultra-high reliability and low latency communication (URLLC) is currently a hot topic in the standardization work of 5G New radio (NR). Future 5G NR networks must be able to successfully deliver (relatively small) packets with a maximum latency of 1 ms and a success probability of reaching ^10-5 (ie 99.999%). There are also use cases for ultra-reliable communications for other latency targets (eg 5ms and 10ms).

Description

This section contains examples and is not intended to be limiting.

In an example of an embodiment, the user equipment of a wireless network is to perform some channel quality measurements according to the settings received by the network, the settings indicate some channel quality measurements to be performed, at least. A set containing one processing value, at least one value comprising either a block-error probability (BLEP) value or a measurement position index, based on execution and channel quality measurement. , Estimating the modulation coding scheme (MCS) value for each processing value in the set, transmitting the estimated MCS value instruction from the user device to the base station of the wireless network, and Methods including are disclosed.

Further examples of embodiments include a computer program comprising code for executing the method of the previous paragraph when the computer program is executed on the processor. A computer program is a computer program according to this paragraph, which is a computer program product comprising a computer readable medium that holds a computer program code embodied in a computer readable medium for use with a computer.

Examples of devices include one or more processors and one or more memories containing computer program code. One or more memory and computer program code, together with one or more processors, is to perform some channel quality measurements on the device, at least by the user equipment of the wireless network, according to the settings received by the network. The setting indicates several channel quality measurements to be performed, comprising a set containing at least one processed value, at least one value comprising either an average block error probability (BLEP) value or a measured position index. Performing, estimating the modulation coding method (MCS) value for each processing value in the set based on the channel quality measurement, and instructing the estimated MCS value from the user equipment to the base station of the wireless network. It is configured to send and to.

In another example of the embodiment, the device is a means of performing some channel quality measurements according to the settings received by the network by the user equipment of the wireless network, where the settings are the several channel qualities performed. Based on the means performed and the channel quality measurement, which indicates the measurement and comprises a set containing at least one processed value, the at least one value comprising either an average block error probability (BLEP) value or a measurement position index. , A means for estimating a modulation coding method (MCS) value for each processing value in the set, and a means for transmitting an instruction of the estimated MCS value from a user device to a base station of a wireless network.

In an example of an embodiment, the settings for some channel quality measurements performed by the user equipment to determine the modulation coding scheme (MCS) are determined by the base station of the wireless network. Determining that it comprises at least several channel quality measurement instructions to be performed and a set containing at least one processing value, transmitting the settings from the base station to the user equipment, and each in the set. A method is disclosed that includes receiving an indication of an estimated MCS value for a processed value from a user device.

Further examples of embodiments include a computer program comprising code for executing the method of the previous paragraph when the computer program is executed on the processor. A computer program is a computer program according to this paragraph, which is a computer program product comprising a computer readable medium that holds a computer program code embodied in a computer readable medium for use with a computer.

Examples of devices include one or more processors and one or more memories containing computer program code. One or more memories and computer program code, along with one or more processors, are configured in the device for at least some channel quality measurements performed by the user equipment to determine the modulation coding scheme (MCS). The setting is to be determined by the base station of the wireless network, the setting to include at least some channel quality measurement instructions to be performed and a set containing at least one processing value. Is configured to be executed from the base station to the user equipment and to receive an instruction of the estimated MCS value for each processing value in the set from the user equipment.

In another example of the embodiment, the apparatus is a means by which the base station of the wireless network determines some settings for channel quality measurement performed by the user equipment to determine the modulation coding scheme (MCS). The setting is a means for determining, which comprises at least some channel quality measurement instructions to be performed and a set containing at least one processing value, and a means for transmitting the setting from the base station to the user equipment. , A means for receiving an instruction of the estimated MCS value for each processing value in the set from the user equipment.

In the attached drawing:

FIG. 1 is a block diagram of one non-limiting, conceivable exemplary system.

FIG. 2 is a graph showing an exemplary time trace of a cell's physical resource block (PRB) allocation.

FIG. 3A shows an exemplary look-up table according to an exemplary embodiment. FIG. 3B shows the mapping of a set of curves corresponding to various modulation coding schemes.

FIG. 4 shows measurement procedures and processes according to an exemplary embodiment.

FIG. 5 shows an exemplary operation and signaling procedure according to an exemplary embodiment.

FIG. 6 shows another exemplary operation and signaling procedure according to an exemplary embodiment.

FIG. 7 shows a non-limiting exemplary message that sets up a Channel Quality Index (CQI) report according to an exemplary embodiment.

FIG. 8 is a logical flow chart of an extended CQI measurement procedure for URLLC, according to an exemplary embodiment, the operation of an exemplary method, the execution of computer program instructions embodied in computer readable memory. The result shows the functions performed by the logic implemented in the hardware and / or the interconnected means of performing the functions. FIG. 9 is a logical flow chart of an extended CQI measurement procedure for URLLC, according to an exemplary embodiment, the operation of an exemplary method, the execution of computer program instructions embodied in computer readable memory. The result shows the functions performed by the logic implemented in the hardware and / or the interconnected means of performing the functions.

Detailed explanation

The following description generally refers to the term LTE (Long term evolution), but there is no limiting intent to this. This description is similarly applicable to other wireless networks such as 5G NR wireless networks as an example. As an example, in the following description, the LTE term "eNB (evolved Node B)" is similarly applicable to 5G base stations (generally referred to as "gNB").

In general, for example, a base station in an LTE network selects a downlink transmission parameter called a modulation coding scheme (MCS) for downlink transmission. The base station selects the MCS based on the expected downlink channel condition. Channel Quality Indicator (CQI) feedback transmitted by the user equipment is used to assist in determining such predicted downlink channel conditions. In the case of LTE, the CQI corresponds to the highest supported MCS that the UE (user equipment) estimates that the UE can decode with an average block error probability (BLEP) of 10% or less. The base station can optimize system capacity and coverage by adjusting the MCS for each user device in response to CQI feedback. This is commonly referred to as link adaptation (LA).

As described in more detail below, some exemplary embodiments relate to channel quality feedback measurement and reporting frameworks that allow accurate and flexible LA for URLLC use cases. LA plays an important role in meeting the stringent requirements of URLLC (such as those mentioned in the background above), as it involves selecting the appropriate MCS to achieve a sufficiently low BLEP. URLLC requirements typically associated with the transmission of small packets at the success probability of the low latency and 1-10 ^-5. The BLEP that each URLLC payload transmission must satisfy is not necessarily ^10-5 , if the associated latency budget allows for one or more HARQ (Hybrid automatic repeat requests) retransmissions. Can be higher. As an example, assuming a moderate latency constraint of 5 to 10 ms, as early a moderate BLEP (e.g. ^{10-2 to 10-3),} and transmits BLEP is the second or third is ^{10 -5} Two or three HARQ transmissions (triggered only if an error occurs in the previous transmission) can be enabled. Therefore, efficient support for services such as URLLC requires a link adaptation mechanism that can accurately control BLEP for each small packet sent.

Another challenge for efficient LA (and scheduling) of small payloads with URLLC constraints is for radio channel and interference variability. Radio channels are, of course, exposed to fluctuations in both the time and frequency domains. Given that the URLLC payloads are generally rather small, they are often scheduled on a slightly smaller number of PRBs and provide little frequency domain averaging. As an example, with 5G NR, the URLLC payload can be reduced to 32 bytes. Furthermore, the time change of SINR (Signal to Interference and noise ratio) experienced by the UE is also extremely large due to the rapid load fluctuation of various cells. Hereinafter, FIG. 2 will be referred to. This drawing shows an exemplary graph 200 of a time trace (obtained from a system level simulation) of cell activity servicing a set of URLLC users. The x-axis of the graph 200 corresponds to the TTI index and the y-axis corresponds to the physical resource block (PRB) index. Graph 200 includes several shaded blocks, each of which identifies a different UE to be serviced in the downlink direction. As can be seen from FIG. 2, PRB activity is a time-varying, random process that greatly increases the time-varying signal-to-noise ratio (SINR) experienced in various UEs. Therefore, even if the UE measures SINR on a particular PRB (or a set of PRBs at a particular point in time), the measurement can change by a few dB immediately afterwards (eg, between one TTI and another). There is. Therefore, accurately tracking the temporal and frequency changes in SINR experienced by the UE uses delays in measuring, formatting, and reporting to eNBs of CQI values, and using received CQI for downlink transmission. It is not realistic because of the processing delay in the eNB to do so.

Information related to these issues can be found in the following references: [1] H. et al. Shariatmadari, Z. Li, M.D. A. Uusitalo, S.A. Iraj, and R.M. Jantti, "Link Adaptation Design for Ultra-Reliable Communications", IEEE International Conference on Communications, May 2016, [ 2] Gwanmo Ku and John MacLaren Walsh, "Resource Allocation and Link Adaptation in LTE and LTE Advanced: A Tutorial" , IEEE Communication Surveys & Tutorials, Vol. 17, No. 3, Q3 2015, [3] K.K. "Frequency domain scheduling for OFDMA with limited and noisy channel feedback," IEEE Vehicle Technology Conference (Autumn VTC) (IEEE Vehicular), by Pedersen et al. Technology Conference (VTC Fall)), 2007, and [4] R1-1770378, "URLLC link adaptation aspects," 3GPP TSG-RAN WG1 NR Expert Conference (3GPP TSG-RAN WG1 NR) Ad-Hoc Meeting), January 2017.

Reference [1] presents an algorithm that selects the optimal set of MCSs that satisfy a particular reliability constraint, assuming that one retransmission is possible. However, details are also given as to what information is needed in either the cell or the UE to perform accurate BLEP-MCS mapping, or how to handle channel variation and old CQI. Absent. Reference [2] defines CQI feedback defined for an average block error rate (BLER) of 10 ^-1 (10%). The UE estimates the CQI based on an average effective SINR measurement with a particular PRB resolution (also known as a subband). Lower (or higher) BLER is generally achieved by using a unique eNB outer loop link adaptation (OLLA) mechanism, such as that presented in Ref. [3]. The OLLA adjusts the BLER according to the received HARQ ACK / NACK feedback message. However, these mechanisms are characterized by slow convergence and BLER-only control. This limits the applicability of these mechanisms to URLLC use cases where BLER control is inadequate. In the case of URLLC, BLEP must be controlled for each transmission to meet the outage requirements for transmission of small payloads. Finally, reference [4] demonstrates the validity of configuring the UE to report multiple CQIs for various BLER goals with respect to 5G NR. However, the details of the specific procedure are not presented.

A description of techniques for extended Channel Quality Indicator (CQI) measurement procedures that can be used, for example for situations such as URLLC, is presented in detail after the description of the system in which the exemplary embodiments can be used.

See FIG. This drawing shows a block diagram of one non-limiting, conceivable exemplary system in which an exemplary embodiment can be implemented. In FIG. 1, the user device (UE) 110 wirelessly communicates with the wireless network 100. A UE is a wireless, typically mobile device that can access a wireless network. The UE 110 includes one or more processors 120 interconnected by one or more buses 127, one or more memories 125, and one or more transmitters / receivers 130. One or more transmitters and receivers 130 include a receiver Rx132 and a transmitter Tx133, respectively. The one or more buses 127 may be an address bus, a data bus, or a control bus, and may be a series of wires on a motherboard or integrated circuit, fiber optics, or other optical communication equipment, and the like. May include an interconnection mechanism of. One or more transmitters and receivers 130 are connected to one or more antennas 128. One or more memories 125 include computer program code 123. The UE 110 includes a feedback module, which comprises one or both of parts 140-1 and / or 140-2 which can be implemented in several forms. The feedback module may be implemented in hardware as the feedback module 140-1, such as implemented as part of one or more processors 120. The feedback module 140-1 may be implemented as an integrated circuit or by other hardware such as a programmable gate array. In another example, the feedback module may be implemented as feedback module 140-2, which is implemented as computer program code 123 and executed by one or more processors 120. For example, one or more memories 125 and computer program code 123, together with one or more processors 120, may be configured to cause the user equipment 110 to perform one or more of the operations described herein. Good. The UE 110 communicates with the eNB 170 via the wireless link 111.

The eNB (Evolved NodeB) 170 is a base station (eg, LTE, Long Term Evolution) that provides access to the wireless network 100 by a wireless device such as the UE 110. The eNB 170 is one or more processors 152, one or more memories 155, one or more network interfaces (N / WI / F (network interface) (s) (s) interconnected by one or more buses 157. ) 161 and one or more transmitters / receivers 160. One or more transmitters and receivers 160 include a receiver Rx162 and a transmitter Tx163, respectively. One or more transmitters and receivers 160 are connected to one or more antennas 158. One or more memories 155 include computer program code 153. The eNB 170 includes an adaptation module, which comprises one or both of parts 150-1 and / or 150-2 which can be implemented in several forms. The adaptation module may be implemented in hardware as an adaptation module 150-1, such as implemented as part of one or more processors 152. The adaptation module 150-1 may be implemented as an integrated circuit or by other hardware such as a programmable gate array. In another example, the adaptation module 150 may be implemented as an adaptation module 150-2 implemented as computer program code 153 and executed by one or more processors 152. For example, one or more memories 155 and computer program code 153, together with one or more processors 152, are configured to cause the eNB 170 to perform one or more of the operations described herein. One or more network interfaces 161 communicate on the network via links 176, 131, and the like. Two or more eNBs 170 communicate using, for example, link 176. The link 176 may be wired, wireless, or both, eg, an X2 interface may be implemented.

The one or more buses 157 may be an address bus, a data bus, or a control bus, a series of wires on a motherboard or integrated circuit, fiber optics, or other optical communication equipment, wireless channels, and the like. It may include any interconnect mechanism such as. As an example, one or more transmitters and receivers 160 may be mounted as a remote radio head (RRH: remote radio head) 195 with other components of the eNB 170 physically different from the RRH. One or more buses 157 could be partially mounted as fiber optic cables to connect other components of the eNB 170 to the RRH195.

The description of the present specification indicates that the "cell" executes the function, but as a matter of course, the eNBs constituting the cell execute the function. The cell forms part of the eNB. That is, there can be a plurality of cells for each eNB. For example, there are three cells in the carrier frequency and associated bandwidth of a single eNB, and each cell is one-third of the 360 degree area so that the coverage area of a single eNB covers approximately an ellipse or circle. Would be possible to cover. Further, each cell can correspond to a single carrier, and the eNB may use a plurality of carriers. Therefore, if there are three 120 degree cells per carrier and there are two carriers, the eNB will have a total of six cells.

The wireless network 100 may include one or more network control elements (NCE) 190 that may include MME (mobility management entity) and / or SGW (serving gateway) functionality. , This provides connectivity with additional networks such as telephone networks and / or data communication networks (eg, the Internet). The eNB 170 is attached to the NCE 190 via the link 131. The link 131 may be implemented as, for example, an S1 interface. The NCE 190 provides one or more processors 175, one or more memories 171 and one or more network interfaces (N / W I / F (s)) 180 interconnected by one or more buses 185. Including. One or more memories 171 include computer program code 173. The one or more memories 171 and the computer program code 173 are configured to cause the NCE 190 to perform one or more operations together with the one or more processors 175.

The wireless network 100 may implement network virtualization. Network virtualization is the process of combining hardware and software network resources and network functionality into a virtual network, a single software-based management entity. Network virtualization involves platform virtualization and is often combined with resource virtualization. Network virtualization can be categorized as either external, which combines a large number of networks or parts of a network into a virtual unit, or internal, which provides network-like functionality to software containers on a single system. To. It should be noted that the virtualization entities resulting from network virtualization are still implemented at some level using hardware such as processors 152 or 175 and memories 155 and 171 and such virtualization entities also provide technical benefits.

Computer-readable memories 125, 155, and 171 may be of any type suitable for the local technical environment, including semiconductor-based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory. , As well as any suitable data storage technology, such as removable memory. Computer-readable memories 125, 155, and 171 may be used as means for performing storage functions. Processors 120, 152, and 175 may be of any type suitable for the local technical environment, and non-limiting examples include general purpose computers, dedicated computers, microprocessors, and digital signal processors (DSPs). , And one or more of processors based on the multi-core processor architecture. Processors 120, 152, and 175 may be used as means for performing functions, such as controlling the UE 110, eNB 170, and other functions described herein.

In general, various embodiments of the user device 110 are, but are not limited to, mobile phones such as smartphones, tablets, personal digital assistants (PDAs) having wireless communication capabilities, and portable computers having wireless communication capabilities. , Image capture devices such as digital cameras with wireless communication capabilities, gaming devices with wireless communication capabilities, music storage and playback devices with wireless communication capabilities, Internet devices that enable wireless Internet access and browsing, wireless communication functions The tablet can include a portable unit or terminal incorporating a combination of such functions.

Thus, although one suitable but non-limiting technical context for the embodiment of the exemplary embodiment has been introduced, the exemplary embodiment will be described more specifically below.

Techniques related to the exemplary embodiments can generally be described with reference to four steps: configuration, UE measurement action, UE measurement processing, and CQI reporting and formatting. Each of these steps will be described in more detail below.

1. 1. Configuration: The eNB configures the UE to measure the experienced channel quality of the downlink on a grid of N time domain resources and M frequency domain resources. The eNB also configures the UE to report a CQI value that results in a BLEP of up to X% when transmitted by the eNB using the MCS corresponding to the CQI index. Typically, in LTE, it is up to the UE implementation to decide how many measurement samples are performed and what kind of filtering is applied to the channel quality measurement. The settings in the steps are performed by the network (eg eNB) and the number of measurement samples is based on the grid of resources. Channel quality can be measured, for example, as the SINR experienced by the UE. Adopting 5G NR terminology, each time domain resource may correspond to a minislot or slot duration, and each frequency domain resource is also known as one PRB or group of PRBs (also known as subbands). ) May consist of. Similarly, for LTE-A, each time domain resource may correspond to one short TTI (sTTI: short TTI), slot, or subframe. The values of N, M, and X may be set from the network to the UE via higher layer signaling, such as by RRC signaling.

2. 2. UE measurement action: The UE measures the experienced downlink channel quality on a grid of N × M radio resources, i.e. by collecting N × M = K measurement samples. The channel quality measurements experienced can be performed as a moving window, so that the measurement samples represent the most recent K measurement samples, which are then described in steps 3 and 4 below. It is used to determine the CQI reported to the eNB.

3. 3. UE measurement processing: The UE sorts K measurement samples of its experienced channel quality and uses these measurement samples to build an empirical sample distribution of the experienced channel quality. From the empirical sample distribution, the UE identifies the experienced channel quality (SINR) at an outage value of X%, corresponding to SINR = SINR_outage. Conceptually, the empirical X percentile (0≤X <100) of K individual values corresponds to the (K * X / 100) th from the lower bound of the sorted K values, indexed from 0.

The UE may utilize a lookup table, such as an internal lookup table, to determine the highest MCS supported for a SINR value of SINR_outage that the UE can decode with a BLEP of X% or less. Therefore, this look-up table comprises BLEP vs. SINR for the supported MCS (or at least the MCS that can be reported as part of the CQI). A non-limiting exemplary lookup table is shown in FIG. 3A. The illustrated lookup table includes three columns, namely a BLEP value column, a SINR value range column, and various MCS columns. Another non-limiting example is a lookup table containing a set of BLEP vs. SINR curves, each corresponding to a supported MCS that may be signaled back to the eNB as part of the CQI report. To do. An example is shown in FIG. 3B, which shows a graph of BLEP vs. SINR values for a set of curves corresponding to various MCSs. The look-up tables in FIGS. 3A and 3B are merely examples and have no limiting intent.

Such SINR vs. BLEP tables for different MCSs may be obtained from extensive link-level simulations by UE modem vendors that reflect UE performance for different MCSs. This table may include points leading to significantly lower BLEP values, including but not limited to, only 10% BLEP, which is sufficient for current LTE CQI schemes. The curves set for the MCS (eg, table values) can differ by 1 dB, for example, in the performance corresponding to a particular quantization, i.e., in correspondence with the SINR to CQI mapping.

It is possible to perform the UE measurement processing steps in a different order than described above and still achieve the same result. As an example, the mapping of SINR to CQI may be performed before determining the empirical X percentile of the quantized value.

4. CQI Report and Format: The UE returns a CQI report to the eNB containing an index pointing to this MCS value.

The steps described above allow, for example, the eNB to send its small URLLC payload to the UE using the MCS corresponding to the latest CQI received from the UE so that the BLEP experienced for transmission is X%. Make sure it does not exceed. This is a process in which the channel quality experienced by the UE is broadly fixed, and this process spans the observed N × M samples, followed by the UE completing steps 3 and 4. It is assumed that the same statistical characteristics are maintained over the short-term window count of the time taken, as well as the delay that the eNB may have before scheduling a new URLLC transmission to the UE following the received CQI.

See also FIG. This drawing shows a simplified diagram of an exemplary measurement procedure and process according to an exemplary embodiment. FIG. 4 includes a heat map 302 showing the experienced channel quality (SINR) performed by the user equipment. Each block in the heatmap 302 corresponds to a radio resource, and each shaded section in the heatmap 302 represents various values of SINR as shown by legend 304. In this example, the user equipment measures the SINR of the N × M measurement sample, as indicated by arrows 306, 308. These samples are then processed to result in an empirical sample distribution 312, as indicated by arrow 310. The UE then identifies the SINR at the X% outer value, which corresponds to SINR = SINR_outage, from the empirical sample distribution 312. This is represented by point 314 in FIG. The identification of the outage value may be based on the UE's internal look-up table.

According to some exemplary embodiments, the eNB may configure the UE with a set of two or more BLEP constraints L = {X ₁ %, X ₂ %, ..., X _J %}. In this case, the UE must report not only the index for a single MCS, but also the index for the MCS value corresponding to each BLEP constraint in set L as part of the CQI report.

According to some exemplary embodiments, UEs were collected when identifying the channel quality (SINR) experienced at an X% outer value from the empirical sample distribution as described in step 3 above. It may be set to use the lowest or Qth lowest value (Q = 1, 2, 3, ..., K) of the K measurements. The value of Q may be set by the eNB as part of step 1 above. This may be particularly useful in cases where the number of K samples is not sufficient to reliably determine the SINR value at the X% outage.

Using the above illustrated technique, the UE effectively represents the MCS that the eNB must use to meet latency requirements, such as the 5G URLCC requirement, to the UE-experienced channel quality X-percentile outage. The corresponding CQI may be reported.

Hereinafter, FIG. 5 will be referred to. This drawing shows exemplary behavior and signaling procedures according to an exemplary embodiment. At 402, the eNB (eg, eNB 170) sends an RRC configuration to the UE (eg, UE 110) that includes at least one BLEP constraint and instructions for the resource being measured. In FIG. 5, at least one BLEP constraint is shown as set L = {X ₁ %, X ₂ %, ..., X _J %}, and the resource indications are N time domain resources to be measured and M. It is shown as N and M corresponding to the frequency domain resource, respectively. At 404, the UE collects K channel quality measurement samples, which is the number corresponding to the N × M radio resource. At 406, the UE sorts the measurement samples, and at 408, the UE reads each BLEP constraint to estimate the corresponding MCS. At 410, the UE transmits an estimated set of MCSs, namely {MCS ₁ , MCS ₂ , ..., MCS _j } to the eNB. If the UE is configured for periodic CQI reporting, the UE may be configured to repeat steps 404-406.

Hereinafter, FIG. 6 will be referred to. This drawing shows another exemplary message for setting up a Channel Quality Indicator (CQI) report according to an exemplary embodiment. At 502, the eNB (eg, eNB 170) is a set of at least one value indicated by Q = {Q ₁ , Q ₂ , ..., Q _j }, as well as an indication of N time domain resources measured by the UE and M. An RRC setting containing each of the instructions for the frequency domain resources is transmitted to the UE (eg, UE 110). At 504, the UE performed channel measurements over duration N and frequency resolution M to collect a few K measurements. The UE, _{Q 1,} Q 2, of the collected the K measurements ..., maintaining only lower value _{Q j} th, at step _506, Q _1, Q 2, ..., low _{Q j} th Estimate the corresponding MCS for each value. At 508, the UE transmits an estimated set of MCSs, namely {MCS ₁ , MCS ₂ , ..., MCS _j } to the eNB. If the UE is configured for periodic CQI reporting, the UE may be configured to repeat steps 504-506.

The RRC setting from eNB to UE will be further described below with reference to an example of non-limiting 5G NR. In this example, it is assumed that there is a 15 kHz subcarrier spacing, a 12 subcarrier PRB size, and a 2-symbol minislot scheduling (ie 0.14 ms TTI size). The gNB may configure the UE as follows: N = 70 must be set so that the UE collects measurements over a 10 ms interval (ie corresponding to 70 minislots) in the time domain. It doesn't become. If the carrier bandwidth consists of 100 PRBs, the gNB could be set to M = 100 or M = 25 (ie, using a subband resolution of 4 PRBs). This will result in: K = 1750 in the case of M = 25, K = 7000 in the case of M = 100. Therefore, the UE will make its CQI report based on 1750 or 7000 measurement samples, respectively. The new CQI value could be reported with a different periodicity than the measurement interval typically done in LTE, such as every 5 ms.

See FIG. 7. This drawing shows a non-limiting exemplary message 700 that sets up a Channel Quality Index (CQI) report according to an exemplary embodiment. Message 700 may be transmitted and used by the eNB to configure the UE for CQI reporting. Message 700 in this example is a periodic CQI report message defined in LTE Release 8 (ie 3GPP36.331, "Radio resource control"), where the CQI is the RRC setup process (RRC connection setup or It is set as part of RRC connection reset). The underlined portion of message 700 indicates additional information that can be used to configure the UE for CQI reporting. In this example, p is an INTER of between 1 and 9 indicating a negative exponent of target BLEP (eg, p = 1 means 10 ^-1 and p = 9 means ^10-9 ). The targetBLEP parameter may be used, for example, in the process described above with reference to FIG. Q is a series of integers between 1 and 99, enabling the process described above with reference to FIG. 6 as an example. The N and M parameters in message 700 are the amount of resources in the time domain and frequency domain to be monitored, respectively. Thus, it will be appreciated that message 700 contains both targetBLEP and Q parameters, but this is not considered limiting. As an example, message 700 may include targetBLEP and / or Q parameters. Moreover, similar changes to later LTE releases and aperiodic CQI will be similar, as will be appreciated by those skilled in the art.

As described above, the UE sends a CQI report from the UE to the eNB. This CQI may be included as part of the UE's channel state information (CSI) report. In the case of LTE, the CSI report is sent to the eNB in LTE PUCCH. Various formats have been defined that support normal or extended cyclic prefixes, multiplexing, or HARQ-ACK that does not rely on 1 or 2 bits (see, eg, 3GPP36.213). New formats may be defined to support extended CQI. In LTE-A Release 10, the maximum length of the CSI report is 21 bits, which corresponds to TDD format 3 using a maximum of 5CC. Release 14 defines formats 4 and 5 with larger messages. Similarly, extended CQI support for URLLC requires a larger message size, and thus a new format, as multiple CQI values can be reported in a single message.

In some examples, the process described above may be applied to both periodic and aperiodic CQI feedback reports. In the case of using aperiodic feedback, the UE can continuously monitor and collect channel quality measurements to reduce the delay between CQI requests and CQI reports. When a CQI request is received from the eNB, the UE may determine the CQI based on the most recent N measurements.

In some examples, the recording window length N is set large enough to provide a relatively good level of accuracy for the percentiles of interest. This is especially significant for URLLC use cases where information up to the 10th- ^5th percentile may be required. In addition, the recording window length can be adjusted according to channel characteristics such as coherence, variability, stationarity, etc. One challenge with this option is that it requires a large number of individual values to obtain reliable measurements of the low percentile, and sorting itself is a costly operation. These problems may be addressed by using a tree structure, where each new individual value can be inserted after the removal of any old value. Pointers to all individual values may be kept in the ring buffer to hold pointers to old values.

In another example, which does not require storing and sorting a large number of samples, a "bias" IIR filter is applied to each channel quality measurement y (t) as follows:
In the equation, E _b (t) is the biased expected value of the channel quality at time t, and _up and f _down are set by the eNB (ie, included in the previously presented RRC configuration message). ). The ratio f _up / f _down determines the bias of the filter: f _up = f _down corresponds to a typical IIR filter aimed at estimating the mean value, with a rather high percentile (eg, symmetric distribution). And the heuristic matching of the single peak distribution (50th percentile), whereas setting _up <f _down biases the estimation to the lower percentile of the distribution.

FIG. 8 is a logical flow chart of an extended Channel Quality Index (CQI) measurement procedure for URLLC. This drawing is executed by the logic implemented in hardware as a result of the operation of one or more exemplary methods, the execution of computer program instructions embodied in computer-readable memory, according to exemplary embodiments. The function and / or the interconnected means of performing the function are further shown. For example, the feedback modules 140-1 and / or 140-2 may include a plurality of blocks of the blocks of FIG. 8, in which case each contained block is an interconnected means of performing a function within the blocks. Is. The block of FIG. 8 is assumed to be performed by the UE 110, for example, at least partially under the control of feedback modules 140-1 and / or 140-2.

See FIG. In an exemplary embodiment, the user equipment of the wireless network is to perform some channel quality measurements according to the settings received by the network, as indicated by block 800, the settings being some performed. Indicates a channel quality measurement of, comprising a set containing at least one processing value, at least one value comprising either an average block error probability (BLEP) value or a measurement position, performed and indicated by block 802. As such, the user estimates the modulation coding method (MCS) value for each processing value in the set based on the channel quality measurement and indicates the estimated MCS value as indicated by block 804. Methods are provided, including transmitting from the device to the base station of the wireless network.

The method may include generating a channel quality distribution based on channel quality measurements by the user equipment.

At least one processing value may include an average block error probability (BLEP) value, and estimating the MCS value determines the outage value by comparing the BLEP value with the channel quality distribution and a look-up table. May include mapping the average value to the MCS value using.

At least one processing value may include a position indication, and estimating the MCS value is to determine the order of the channel quality measurement and to estimate the MCS value for the channel quality measurement corresponding to the measurement position index. And include.

Channel quality measurements are ordered from lowest channel quality to highest channel quality.

The settings may include instructions for the number of time domain resources and frequency domain division.

The set may include two or more processed values, and transmitting may include transmitting an indication of an estimated MCS value for each of the two or more processed values.

The settings may be radio resource control (RRC) settings, and performing measurements is performing periodic channel quality measurements based on the RRC settings and aperiodically based on the RRC settings. It may include at least one of performing various channel quality measurements.

The channel quality measurement may be a signal-to-noise ratio (SINR) measurement.

In another exemplary embodiment, the device may include at least one processor and at least one non-temporary memory containing computer program code, at least one memory and computer program code with at least one processor. The device is to perform some channel quality measurements according to the settings received by the network, at least by the user equipment of the wireless network, the settings indicate the several channel quality measurements performed and at least one. Each processed value in the set, with a set containing the processed values, with at least one value having either an average block error probability (BLEP) value or a measured position index, based on the execution and channel quality measurement. It is configured to estimate a modulation coding method (MCS) value for a computer and transmit an instruction of the estimated MCS value from a user device to a base station of a wireless network.

At least one memory and computer program code, together with at least one processor, may be configured to cause the device to perform at least the user equipment to generate a channel quality distribution based on channel quality measurements.

At least one processing value may include an average block error probability (BLEP) value, and estimating the MCS value determines the outage value by comparing the BLEP value with the channel quality distribution and a look-up table. May include mapping the average value to the MCS value using.

At least one processing value may include a position indication, and estimating the MCS value is to determine the order of the channel quality measurement and to estimate the MCS value for the channel quality measurement corresponding to the measurement position index. And include.

Channel quality measurements are ordered from lowest channel quality to highest channel quality.

The settings may include instructions for the number of time domain resources and frequency domain division.

The set may include two or more processed values, and transmitting may include transmitting an indication of an estimated MCS value for each of the two or more processed values.

The settings may be radio resource control (RRC) settings, and performing measurements is performing periodic channel quality measurements based on the RRC settings and aperiodically based on the RRC settings. It may include at least one of performing various channel quality measurements.

The channel quality measurement may be a signal-to-noise ratio (SINR) measurement.

The user equipment may include a device according to any one of paragraphs [0069] to [0077].

According to another exemplary embodiment, the device is a means of performing some channel quality measurements according to the settings received by the network by the user equipment of the wireless network, and the settings are some performed. A means to perform and a channel quality measurement that indicates a channel quality measurement and comprises a set containing at least one processed value, the at least one value having either an average block error probability (BLEP) value or a measurement position index. Based on this, even if a means for estimating a modulation coding method (MCS) value for each processing value in the set and a means for transmitting an instruction of the estimated MCS value from a user device to a base station of a wireless network are provided. Good.

FIG. 9 is a logical flow chart of an extended Channel Quality Index (CQI) measurement procedure for URLLC. This drawing is executed by the logic implemented in hardware as a result of the operation of one or more exemplary methods, the execution of computer program instructions embodied in computer-readable memory, according to exemplary embodiments. The function and / or the interconnected means of performing the function are further shown. For example, adaptation modules 150-1 and / or 150-2 may include multiple blocks of the blocks of FIG. 9, where each contained block is an interconnected means of performing a function within the block. Is. The block of FIG. 9 is assumed to be performed by a base station such as the eNB 170, for example, at least partially under the control of adaptation modules 150-1 and / or 150-2.

See FIG. In an exemplary embodiment, the base station of the wireless network sets up some channel quality measurements performed by the user equipment to determine the modulation coding scheme (MCS), as indicated by block 900. To determine, the setting indicates several channel quality measurements to be performed, comprising a set containing at least one processing value, at least one value being the average block error probability (BLEP) value or measurement position. Determining, as indicated by block 902, transmitting the settings from the base station to the user equipment, and estimating for each processing value in the set, as indicated by block 904. A method is provided that includes receiving an indication of the MCS value from the user equipment.

The set may include one or more average block error probability (BLEP) values.

The set may include one or more measurement position indexes.

The settings may include instructions for the number of time domain resources and frequency domain division.

The setting may be a radio resource control (RRC) setting and indicates whether the channel quality measurement is periodic or aperiodic.

In this method, among the estimated MCS values instructed by the user device, the one used for the downlink transmission is selected, and the downlink transmission is transmitted to the user device based on the selected MCS value. It may include things.

Choosing the estimated MCS value may be based on the latency requirements of the wireless network.

According to another exemplary embodiment, the device may include at least one processor and at least one non-temporary memory containing computer program code, at least one memory and at least one computer program code. Along with one processor, the device is to determine at least some settings for channel quality measurement performed by the user equipment to determine the modulation coding scheme (MCS) by the base station of the wireless network. The settings include, determine, with at least some channel quality measurement instructions to be performed and a set containing at least one processing value, send the settings from the base station to the user equipment, and within the set. It is configured to receive an instruction of the estimated MCS value for each processing value from the user device and execute the operation.

The set may include one or more average block error probability (BLEP) values.

The set may include one or more measurement position indexes.

The settings may include instructions for the number of time domain resources and frequency domain division.

The setting may be a radio resource control (RRC) setting and indicates whether the channel quality measurement is periodic or aperiodic.

At least one memory and computer program code, along with at least one processor, is selected by the device to select at least one of the estimated MCS values instructed by the user equipment to be used for downlink transmission. Based on the MCS value, the user equipment may be configured to perform downlink transmission transmission.

Choosing the estimated MCS value may be based on the latency requirements of the wireless network.

The base station may include a device according to any one of paragraphs [0088]-[0094].

According to yet another embodiment, the device determines the settings for some channel quality measurements performed by the user equipment to determine the modulation coding scheme (MCS) by the base station of the wireless network. Means, a means of determining, the setting comprising at least some channel quality measurement instructions to be performed and a set containing at least one processing value, and a means of transmitting the setting from the base station to the user equipment. And a means for receiving an instruction of the estimated MCS value for each processing value in the set from the user equipment.

The communication system may include a device according to any one of paragraphs [0069] to [0077] and a device according to any one of paragraphs [0088] to [0094].

The computer program may include program code for executing the method according to any of paragraphs [0060] to [0068] or [0081] to [0087]. The computer program may be a computer program product comprising a computer readable medium that holds the computer program code embodied in the computer readable medium for use with the computer.

Without limiting the scope, interpretation, or application of the appended claims, the technical effect of one or more embodiments disclosed herein is that sporadic transmission of small packets is eNB. Addressing the LA challenges of URLLC traffic, which leads to rapidly changing interference that is difficult to track on the side. At the same time, multiple CQI indexes reported to the eNB, each with a different BLEP constraint associated with it, allow for spectrally efficient link adaptation. This is because BLEP can be flexibly adjusted according to the latency and reliability constraints of each individual URLLC packet. Another technical effect of one or more of the exemplary embodiments disclosed herein is to help meet URLLC requirements in difficult environments where interference fluctuates rapidly. Another technical effect of one or more of the exemplary embodiments disclosed herein is that only one CQI value is reported for each BLEP constraint. This results in lower uplink feedback overhead compared to the configuration of some LTE CQI reports where CQI is reported on a subband basis.

Embodiments of the present application may be implemented in software (executed by one or more processors), hardware (eg, application-specific integrated circuits), or a combination of software and hardware. In an exemplary embodiment, the software (eg, application logic, instruction set) is maintained on any of a variety of conventional computer-readable media. In the context of this document, "computer-readable medium" means including, storing, transmitting, or propagating instructions used by or in connection with an instruction execution system, device, or device, such as a computer. , Or any medium or means capable of transporting, an example of a computer is illustrated and shown, eg, in FIG. A computer-readable medium is any medium or means capable of containing, storing, and / or transporting instructions used by or in connection with an instruction execution system, device, or device, such as a computer. It may include a computer-readable storage medium (eg, memory 125, 155, 171 or other device). Computer-readable storage media do not include propagating signals.

If desired, the various functions described herein can be performed in different orders and / or simultaneously with each other. Further, if necessary, one or more of the above functions may be optional or combined.

Although various aspects of the invention are described in independent claims, other aspects of the invention are not limited to the combinations expressly stated in the claims, but other described embodiments and / or It has a combination of features from dependent claims and features from independent claims.

Further, it should be pointed out that in the specification of the present application, the above-mentioned matters describe the exemplary embodiments of the present invention, but these descriptions should not be taken in a limited sense. On the contrary, it can be added without departing from the scope of the invention as defined in the appended claims.

The following abbreviations that may be included herein and / or drawings are defined as follows:
3GPP Third Generation Partnership Project ⁽³ rd generation partnership project)
BLER block error rate BLEP block error probability CC component carrier
CDF Cumulative Distribution Function (Cumulative Distribution function)
CQI channel quality index eNB (or eNodeB) Evolved node B (for example, LTE base station)
HARQ Hybrid Automatic Retransmission Request I / F Interface LA Link Adaptation LTE Long Term Evolution MCS Modulation Coding Method MME Mobility Management Entity NCE Network Control Element N / W Network PRB Physical Resource Block RRH Remote Radiohead Rx Receiver SGW Serving Gateway SINR Signal Pair Interference noise ratio Tx transmitter quality of service (Quality of service)
UE user equipment (eg wireless, typically mobile)
URLLC Ultra-high reliability and low latency communication

Claims (23)

A method performed by a user device in a wireless network,
Performing channel quality measurements for each of the plurality of time frequency resources according to the settings received from the network, the settings include information indicating the number of channel quality measurements performed and at least one. Performing the above, including the measurement position index,
Identifying the modulation coding method (MCS) value for the measurement position index and
Sending information indicating the specified MCS value to the wireless network and
Including, the above-mentioned identification
To identify the measured value derived from the measurement position index from the plurality of measured values obtained by the channel quality measurement, which are arranged from the one with the lowest channel quality to the one with the highest channel quality.
Identifying the MCS value corresponding to the specified measurement value and
How to include. A method performed by a user device in a wireless network,
According to the settings received from the network, the method comprising: performing channel quality measurements for each of a plurality of time-frequency resources, the setting, information indicating the number of to be executed the channel quality measurement, at least one The above-mentioned actions, including one average block error probability (BLEP) value, and
Identifying the modulation coding method (MCS) value for the average block error probability and
Sending information indicating the specified MCS value to the wireless network and
Including, the above-mentioned identification
Creating a cumulative distribution function using the measured values of the multiple channel quality measurements,
Identifying the channel quality value at which the value of the cumulative distribution function is the average block error probability value,
Identifying the MCS value corresponding to the identified channel quality value and
Including methods. The method of claim 1 or 2, wherein identifying the MCS value corresponding to the identified channel quality value comprises specifying the MCS value using a look-up table. The method of any one of claims 1-3, wherein the information indicating the number of channel quality measurements to be performed includes instructions for the number of time domain resources and frequency domain division. The setting is a radio resource control (RRC) setting, and performing the measurement is
Performing periodic channel quality measurements based on the RRC settings
Performing aperiodic channel quality measurements based on the RRC settings
The method according to any one of claims 1 to 4, which comprises at least one of. The method according to any one of claims 1 to 5, wherein the channel quality measurement is a signal-to-interference noise ratio (SINR) measurement. A device including a processing means and a storage means, wherein the device stores a program instruction, and when the program instruction is executed by the processing means, the device is subjected to any one of claims 1 to 6. A device configured to perform the described method. A means of performing channel quality measurements on each of a plurality of time frequency resources according to settings received from the network, the settings being information indicating the number of such channel quality measurements performed and at least one measurement. The means to be performed, including the position index, and
A means for identifying a modulation coding method (MCS) value for the measurement position index, and
A means for transmitting information indicating the specified MCS value to the base station of the wireless network, and
And the above-mentioned identification
To identify the measured value derived from the measurement position index from the plurality of measured values obtained by the channel quality measurement, which are arranged from the one with the lowest channel quality to the one with the highest channel quality.
Identifying the MCS value corresponding to the specified measurement value and
Including equipment. According to the settings received from the network, and means for performing channel quality measurements for each of a plurality of time-frequency resources, the setting, information indicating the number of to be executed the channel quality measurement, at least one The means to be performed, including an average block error probability (BLEP) value, and
Means for specifying the modulation coding method (MCS) value for the average block error probability, and
A means for transmitting information indicating the specified MCS value to the wireless network, and
And the above-mentioned identification
Creating a cumulative distribution function using the measured values of the multiple channel quality measurements,
Identifying the channel quality value at which the value of the cumulative distribution function is the average block error probability value,
Identifying the MCS value corresponding to the identified channel quality value and
A device that comprises. A user device comprising the device according to any one of claims 7 to 9. The method performed by the base station of the wireless network,
Sending to the user equipment a setting for multiple channel quality measurements performed by the user equipment to determine the modulation coding scheme (MCS), the setting is the channel quality performed. The transmission, including information indicating the number of measurements and at least one measurement position index.
Receiving information representing the MCS value corresponding to the measurement position index from the user device and
How to include. The method performed by the base station of the wireless network,
Sending to the user equipment a setting for multiple channel quality measurements performed by the user equipment to determine the modulation coding scheme (MCS), the setting is the channel quality performed. That transmission, including information indicating the number of measurements and at least one average block error probability (BLEP) value.
Receiving information representing the MCS value corresponding to the average block error probability value from the user device, and
How to include. The method of claim 11 or 12, wherein the information indicating the number of channel quality measurements to be performed includes instructions for the number of time domain resources and frequency domain division. The method of any one of claims 11-13, wherein the setting is a radio resource control (RRC) setting, which indicates whether the channel quality measurement is periodic or aperiodic. Among the received MCS values, selecting the one used for downlink transmission and
To transmit the downlink transmission to the user device based on the selected MCS value, and
The method according to any one of claims 11 to 14, further comprising. The method of claim 15, wherein selecting the estimated MCS value is based on the latency requirement of the wireless network. A device including a processing means and a storage means, wherein the device stores a program instruction, and when the program instruction is executed by the processing means, the device is subjected to any one of claims 11 to 16. A device configured to perform the described method. A means of transmitting a set for multiple channel quality measurements performed by a user device to the user device to determine a modulation coding scheme (MCS), the setting being the channel quality performed. The means of transmission, including information indicating the number of measurements and at least one measurement position index.
A means for receiving information representing the MCS value corresponding to the measurement position index from the user device, and
A device equipped with. A means of transmitting a set for multiple channel quality measurements performed by a user device to the user device to determine a modulation coding scheme (MCS), the setting being the channel quality performed. The means to transmit, including information indicating the number of measurements and at least one average block error probability (BLEP) value.
A means for receiving information representing an MCS value corresponding to the average block error probability value from the user device, and
How to prepare. The device according to any one of claims 17 to 19, which is a base station. A communication system comprising the apparatus according to any one of claims 7 to 9 and the apparatus according to any one of claims 17 to 19. A computer program comprising a program code configured to cause the device to perform the method according to any one of claims 1 to 6, when executed by the processing means of the device. A computer program comprising a program code configured to cause the device to perform the method according to any one of claims 11 to 16 when executed by the processing means of the device.