EP3577811A1

EP3577811A1 - Enchanced channel quality indicator (cqi) measurement procedure for urllc

Info

Publication number: EP3577811A1
Application number: EP18748717.8A
Authority: EP
Inventors: Guillermo POCOVI; Klaus Pedersen; Jens Steiner; Beatriz SORET
Original assignee: Nokia Technologies Oy
Current assignee: Nokia Technologies Oy
Priority date: 2017-02-03
Filing date: 2018-01-17
Publication date: 2019-12-11
Also published as: JP2020506622A; EP3577811A4; JP6811333B2; WO2018142020A1

Abstract

A method is provided including performing, by a user equipment of a wireless network, a number of channel quality measurements according to a configuration received by the network, the configuration being indicative of the number of channel quality measurements to be performed and comprises a set comprising at least one processing value, the at least one value comprising either an average block-error probability (BLEP) value or a measurement position index (800); estimating a modulation and coding scheme (MCS) value for each processing value in the set based on the channel quality measurements (802); and transmitting, from the user equipment to a base station of the wireless network, an indication of the estimated MCS value (804).

Description

Enhanced Channel Quality Indicator (CQI) measurement procedure for URLLC

TECHNICAL FIELD

[0001] This invention relates generally to wireless networks and, more specifically, relates to channel quality indicator (CQI) measurement and reporting procedure, link adaptation (LA), and support of ultra-reliable low-latency communications (URLLC) in radio systems.

BACKGROUND

[0002] This section is intended to provide a background or context to the invention disclosed below. The description herein may include concepts that could be pursued, but are not necessarily ones that have been previously conceived, implemented or described. Therefore, unless otherwise explicitly indicated herein, what is described in this section is not prior art to the description in this application and is not admitted to be prior art by inclusion in this section. Abbreviations that may be found in the specification and/or the drawing figures are defined below, after the main part of the detailed description section.

[0003] Ultra-Reliable Low-Latency Communications (URLLC) is currently a popular topic in 5G New radio (NR) standardization activities. Future 5G NR networks must be able to deliver a (relatively small) packet successfully with a maximum latency of 1 ms, and probability of success of up to 10^"5 (or 99.999%). There are use cases of ultra-reliable communication also for other latency targets (such as 5 ms and 10 ms for example).

BRIEF SUMMARY

[0004] This section is intended to include examples and is not intended to be limiting.

[0005] In an example of an embodiment, a method is disclosed that includes performing, by a user equipment of a wireless network, a number of channel quality measurements according to a configuration received by the network, wherein the configuration is indicative of the number of channel quality measurements to be performed and comprises a set comprising at least one processing value, the at least one value comprising either an average block-error probability (BLEP) value or a measurement position index; estimating a modulation and coding scheme (MCS) value for each processing value in the set based on the channel quality measurements; and transmitting, from the user equipment to a base station of the wireless network, an indication of the estimated MCS value.

[0006] An additional example of an embodiment includes a computer program, comprising code for performing the method of the previous paragraph, when the computer program is run on a processor. The computer program according to this paragraph, wherein the computer program is a computer program product comprising a computer-readable medium bearing computer program code embodied therein for use with a computer.

[0007] An example of an apparatus includes one or more processors and one or more memories including computer program code. The one or more memories and the computer program code are configured to, with the one or more processors, cause the apparatus to at least: perform, by a user equipment of a wireless network, a number of channel quality measurements according to a configuration received by the network, wherein the configuration is indicative of the number of channel quality measurements to be performed and comprises a set comprising at least one processing value, the at least one value comprising either an average block-error probability (BLEP) value or a measurement position index; estimate a modulation and coding scheme (MCS) value for each processing value in the set based on the channel quality measurements; and transmit, from the user equipment to a base station of the wireless network, an indication of the estimated MCS value.

[0008] In another example of an embodiment, an apparatus comprises means for performing, by a user equipment of a wireless network, a number of channel quality measurements according to a configuration received by the network, wherein the configuration is indicative of the number of channel quality measurements to be performed and comprises a set comprising at least one processing value, the at least one value comprising either an average block-error probability (BLEP) value or a measurement position index; means for estimating a modulation and coding scheme (MCS) value for each processing value in the set based on the channel quality measurements; and means for transmitting, from the user equipment to a base station of the wireless network, an indication of the estimated MCS value.

[0009] In an example of an embodiment, a method is disclosed that includes determining, by a base station of a wireless network, a configuration for a number of channel quality measurements to be performed by a user equipment for determining a modulation and coding scheme (MCS), wherein the configuration comprises at least an indication of the number of channel quality measurements to be performed and a set comprising at least one processing value; transmitting, from the base station to the user equipment, the configuration; and receiving, from the user equipment, an indication of the estimated MCS value for each processing value in the set.

[0010] An additional example of an embodiment includes a computer program, comprising code for performing the method of the previous paragraph, when the computer program is run on a processor. The computer program according to this paragraph, wherein the computer program is a computer program product comprising a computer-readable medium bearing computer program code embodied therein for use with a computer.

[0011] An example of an apparatus includes one or more processors and one or more memories including computer program code. The one or more memories and the computer program code are configured to, with the one or more processors, cause the apparatus to perform at least the following: determine, by a base station of a wireless network, a configuration for a number of channel quality measurements to be performed by a user equipment for determining a modulation and coding scheme (MCS), wherein the configuration comprises at least an indication of the number of channel quality measurements to be performed and a set comprising at least one processing value; transmit, from the base station to the user equipment, the configuration; and receive, from the user equipment, an indication of the estimated MCS value for each processing value in the set.

[0012] In another example of an embodiment, an apparatus comprises means for determining, by a base station of a wireless network, a configuration for a number of channel quality measurements to be performed by a user equipment for determining a modulation and coding scheme (MCS), wherein the configuration comprises at least an indication of the number of channel quality measurements to be performed and a set comprising at least one processing value; means for transmitting, from the base station to the user equipment, the configuration; and means for receiving, from the user equipment, an indication of the estimated MCS value for each processing value in the set.

BRIEF DESCRIPTION OF THE DRAWINGS [0013] In the attached Drawing Figures:

[0014] FIG. 1 is a block diagram of one possible and non-limiting exemplary system; [0015] FIG. 2 is a graph showing an example time trace of physical resource block (PRB) allocation for a cell;

[0016] FIG. 3A illustrates an example look-up table in accordance with example embodiments, and FIG. 3B illustrates a mapping of a set of curves corresponding to different modulation and coding schemes;

[0017] FIG. 4 illustrates a measurement procedure and processing in accordance with an example embodiment;

[0018] FIG. 5 illustrates an example operation and signaling procedure according to an example embodiment;

[0019] FIG. 6 illustrates another example operation and signaling procedure according to an example embodiment;

[0020] FIG. 7 illustrates a non-limiting example message for configuring Channel Quality Indicator (CQI) reporting according to an example embodiment; and

[0021] FIGS. 8-9 are a logic flow diagram for enhanced CQI measurement procedure for URLLC, and illustrate the operation of exemplary methods, a result of execution of computer program instructions embodied on a computer readable memory, functions performed by logic implemented in hardware, and/or interconnected means for performing functions in accordance with exemplary embodiments.

DETAILED DESCRIPTION

[0022] The description below generally refers to LTE terms, however this is not intended to be limiting. The description is equally applicable to other wireless networks, such as 5G NR wireless networks for example. For example, the LTE term 'eNB' is equally applicable to a 5G base station (commonly referred to as a 'gNB') for the purposes of the description below.

[0023] Generally, a base station in, e.g., an LTE network selects downlink transmission parameters, referred to as the modulation and coding scheme (MCS), for downlink transmissions. The base station selects the MCS based on predicted downlink channel conditions. Channel Quality Indicator (CQI) feedback transmitted by a user equipment is used to help determine these predicted downlink channel conditions. For LTE, the CQI corresponds to the highest supported MCS that the UE estimates it can decode with an average block-error probability (BLEP) no larger than 10%. The base station can optimize system capacity and coverage by adjusting the MCS for each user equipment depending on the CQI feedback. This is commonly referred to as Link Adaptation (LA).

[0024] As discussed in more detail below, some example embodiments relate to measurement and reporting framework of the channel quality feedback that allows accurate and flexible LA for URLLC use cases. LA plays an important role in satisfying the URLLC stringent requirements (such as those mentioned in the background above) since it involves selecting an appropriate MCS such that it achieves a sufficiently low BLEP. URLLC requirements are typically associated with transmission of small packets with low latency and 1-10^"5 probability of success. The BLEP that each URLLC payload transmission needs to fulfill is not necessarily 10^"5 but can be higher if the associated latency budget allows one or more HARQ retransmissions. For example, if assuming a relaxed latency constraint of 5-10 ms, two or three HARQ transmissions can be allowed: an initial one with a moderate BLEP (e.g. 10^"2 - 10^"3), and a second or third transmission (only triggered when an error occurs in the previous transmission) with a BLEP of 10^"5. Efficient support for URLLC-alike services therefore requires link adaptation mechanisms where the BLEP can be controlled accurately per small packet transmission.

[0025] Another challenge for efficient LA (and scheduling) of small payloads with URLLC constraints relates to radio channel and interference variations. The radio channel is obviously subject to both time- and frequency-domain variations. Given that URLLC payloads are generally rather small, they are often scheduled over rather few PRBs, offering little frequency domain averaging. For example, in 5G NR URLLC payloads may be as small as 32 bytes. In addition, the UEs experienced SINR is also highly time-variant due to rapid load fluctuations of the different cells. Referring now to FIG. 2, this figure shows an example graph 200 of a time trace of a cell activity (obtained from system-level simulations) serving a set of URLLC users. The x-axis of graph 200 corresponds to the TTI index and the y-axis corresponds to the physical resource block (PRB) index. The graph 200 includes a number of shaded blocks, where each shade identifies a different UE which is served in the downlink direction. As can be seen from FIG. 2, the PRB activity is a time-variant random process, which causes the experienced signal-to-interference-plus-noise ratio (SINR) at the different UEs to be highly time-variant. Thus, if a UE measures SINR on a certain PRB (or set of PRBs at a given time), the measurement might change by several dBs shortly after (e.g. from one TTI to another). Therefore, it is unrealistic to accurately track time- and frequency- variants of UE experienced SINR due to delays in measuring, formatting, and reporting CQI values to the eNB, as well as processing delays at the eNB for using the received CQI for downlink transmissions.

[0026] Information relevant to these problems can be found in the following documents: [1] H. Shariatmadari, Z. Li, M. A. Uusitalo, S. Iraji and R. 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, Third Quarter 2015; [3] K. Pedersen, et al, "Frequency domain scheduling for OFDMA with limited and noisy channel feedback", IEEE Vehicular Technology Conference (VTC Fall), 2007; and [4] Rl- 1700378, "URLLC link adaptation aspects", 3 GPP TSG-RAN WG1 NR Ad-Hoc Meeting, Jan. 2017.

[0027] Document [1] presents an algorithm to select an optimal set of MCS to fulfill a certain reliability constraint, assuming one retransmission is allowed. However, no details are provided on what information is required at either the cell or UE to perform accurate BLEP-MCS mapping, or how to deal with the channel variations and outdated CQI. Document [2] defines the CQI feedback defined for an average block error rate (BLER) of 10^"1 (10%). The UE estimates the CQI based on mean effective SINR measurements with a certain PRB resolution (a.k.a. sub-band). Lower (or higher) BLER is generally achieved by use of proprietary eNB outer loop link adaptation (OLLA) mechanisms, such as the one presented in Document [3] . OLLA tunes the BLER according to the received HARQ ACK/NACK feedback messages. However, these mechanisms are characterized by slow convergence and only controlling the BLER. This limits their applicability to URLLC use cases where controlling the BLER is insufficient. For URLLC, the BLEP must be controlled for each transmission to fulfil the outage requirement for small payload transmissions. Finally, document [4] relates to 5G NR and expresses the relevance of configuring a UE to report multiple CQIs for different BLER targets. However, details on the specific procedure are not presented.

[0028] Description of techniques for enhanced Channel Quality Indicator (CQI) measurement procedure, which may be used for situations such as URLLC for example, is presented in detail after a system into which example embodiments may be used is described.

[0029] Turning to FIG. 1, this figure shows a block diagram of one possible and non- limiting exemplary system in which example embodiments may be practiced. In FIG. 1 , a user equipment (UE) 1 10 is in wireless communication with a wireless network 100. A UE is a wireless, typically mobile device that can access a wireless network. The UE 1 10 includes one or more processors 120, one or more memories 125, and one or more transceivers 130 interconnected through one or more buses 127. Each of the one or more transceivers 130 includes a receiver, Rx, 132 and a transmitter, Tx, 133. The one or more buses 127 may be address, data, or control buses, and may include any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, fiber optics or other optical communication equipment, and the like. The one or more transceivers 130 are connected to one or more antennas 128. The one or more memories 125 include computer program code 123. The UE 1 10 includes a feedback module, comprising one of or both parts 140-1 and/or 140-2, which may be implemented in a number of ways. The feedback module may be implemented in hardware as feedback module 140- 1 , such as being implemented as part of the one or more processors 120. The feedback module 140-1 may be implemented also as an integrated circuit or through 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 is executed by the one or more processors 120. For instance, the one or more memories 125 and the computer program code 123 may be configured to, with the one or more processors 120, cause the user equipment 1 10 to perform one or more of the operations as described herein. The UE 1 10 communicates with eNB 170 via a wireless link 11 1.

[0030] The eNB (evolved NodeB) 170 is a base station (e.g., for LTE, long term evolution) that provides access by wireless devices such as the UE 1 10 to the wireless network 100. The eNB 170 includes one or more processors 152, one or more memories 155, one or more network interfaces (N/W I/F(s)) 161 , and one or more transceivers 160 interconnected through one or more buses 157. Each of the one or more transceivers 160 includes a receiver, Rx, 162 and a transmitter, Tx, 163. The one or more transceivers 160 are connected to one or more antennas 158. The one or more memories 155 include computer program code 153. The eNB 170 includes an adaptation module, comprising one of or both parts 150-1 and/or 150-2, which may be implemented in a number of ways. The adaptation module may be implemented in hardware as adaptation module 150-1 , such as being implemented as part of the one or more processors 152. The adaptation module 150-1 may be implemented also as an integrated circuit or through other hardware such as a programmable gate array. In another example, the adaptation module 150 may be implemented as adaptation module 150-2, which is implemented as computer program code 153 and is executed by the one or more processors 152. For instance, the one or more memories 155 and the computer program code 153 are configured to, with the one or more processors 152, cause the eNB 170 to perform one or more of the operations as described herein. The one or more network interfaces 161 communicate over a network such as via the links 176 and 131. Two or more eNBs 170 communicate using, e.g., link 176. The link 176 may be wired or wireless or both and may implement, e.g., an X2 interface.

[0031] The one or more buses 157 may be address, data, or control buses, and may include any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, fiber optics or other optical communication equipment, wireless channels, and the like. For example, the one or more transceivers 160 may be implemented as a remote radio head (RRH) 195, with the other elements of the eNB 170 being physically in a different location from the RRH, and the one or more buses 157 could be implemented in part as fiber optic cable to connect the other elements of the eNB 170 to the RRH 195.

[0032] It is noted that description herein indicates that "cells" perform functions, but it should be clear that the eNB that forms the cell will perform the functions. The cell makes up part of an eNB. That is, there can be multiple cells per eNB. For instance, there could be three cells for a single eNB carrier frequency and associated bandwidth, each cell covering one-third of a 360-degree area so that the single eNB's coverage area covers an approximate oval or circle. Furthermore, each cell can correspond to a single carrier and an eNB may use multiple carriers. So, if there are three 120 degree cells per carrier and two carriers, then the eNB has a total of 6 cells.

[0033] 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, and which provides connectivity with a further network, such as a telephone network and/or a data communications network (e.g., the Internet). The eNB 170 is coupled via a link 131 to the NCE 190. The link 131 may be implemented as, e.g., an S I interface. The NCE 190 includes one or more processors 175, one or more memories 171 , and one or more network interfaces (N/W I/F(s)) 180, interconnected through one or more buses 185. The 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, with the one or more processors 175, cause the NCE 190 to perform one or more operations. [0034] The wireless network 100 may implement network virtualization, which is the process of combining hardware and software network resources and network functionality into a single, software-based administrative entity, a virtual network. Network virtualization involves platform virtualization, often combined with resource virtualization. Network virtualization is categorized as either external, combining many networks, or parts of networks, into a virtual unit, or internal, providing network- like functionality to software containers on a single system. Note that the virtualized entities that result from the network virtualization are still implemented, at some level, using hardware such as processors 152 or 175 and memories 155 and 171 , and also such virtualized entities create technical effects.

[0035] The computer readable memories 125, 155, and 171 may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The computer readable memories 125, 155, and 171 may be means for performing storage functions. The processors 120, 152, and 175 may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on a multi-core processor architecture, as non- limiting examples. The processors 120, 152, and 175 may be means for performing functions, such as controlling the UE 1 10, eNB 170, and other functions as described herein.

[0036] In general, the various embodiments of the user equipment 1 10 can include, but are not limited to, cellular telephones such as smart phones, tablets, personal digital assistants (PDAs) having wireless communication capabilities, portable computers having wireless communication capabilities, image capture devices such as digital cameras having wireless communication capabilities, gaming devices having wireless communication capabilities, music storage and playback appliances having wireless communication capabilities, Internet appliances permitting wireless Internet access and browsing, tablets with wireless communication capabilities, as well as portable units or terminals that incorporate combinations of such functions.

[0037] Having thus introduced one suitable but non-limiting technical context for the practice of example embodiments, the example embodiments will now be described with greater specificity. [0038] Techniques related to example embodiments can generally be described with reference to the following four steps: configuration, UE measurement action, UE measurement processing, and CQI reporting and formatting. Each of these steps is detailed more thoroughly below.

[0039] 1. Configuration: An eNB configures a UE to measure downlink experienced channel quality 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 at maximum will result in BLEP of X% if the eNB transmits with MCS corresponding to the index of CQI. Typically, in LTE it is left to the UE implementation to determine how many measurement samples are performed and what kind of filtering is applied for the channel quality measurements whereas the configuration in this step is performed by the network (e.g. eNB) and the number of measurement samples is based on the grid of resources. The channel quality can, for example, be measured as the experienced SINR by the UE. Adopting the 5G NR terminology, each time-domain resource may correspond to the duration of a mini-slot or slot, and each frequency domain resource may consist of one PRB, or a group of PRBs (also known as a subband). Similarly, for LTE-A, each time-domain resource may correspond to one short TTI (sTTI), slot, or subframe. The values of N, M, and X may be configured from the network for the UE via higher layer signaling such as by RRC signaling for example.

[0040] 2. UE Measurement Action: The UE measures the experienced downlink channel quality on the grid of NxM radio resources, namely, by collecting NxM=K measurement samples. The measurement of the experienced channel quality can be performed as a moving window, such that the measurement samples represent the most recent K measurement samples that are used for determining the CQI that is subsequently reported to the eNB, as described in steps 3 and 4 below.

[0041] 3. UE measurement processing: The UE sorts the K measurement samples of its experienced channel quality, and uses these measurement samples to build an empirical sample distribution of the experienced channel quality. The UE identifies the experienced channel quality (SINR) at the outage value of X% from the empirical sample distribution, corresponding to SINR=SINR_outage. Conceptually, the empirical X%-ile (0<=X<100) of the K individual values corresponds to the floor(K*X/100)'th ofthe sorted K values, indexing from 0. [0042] The UE may utilize a look-up table, such as an internal look-up table, to determine the highest supported MCS for an SINR value of SINR outage that it can decode with a BLEP no higher than X%. Thus, this look-up table comprises BLEP versus SINR for the supported MCSs (or at least MCSs that can be reported as part of the CQI). A non-limiting example lookup table is shown in FIG. 3 A, where the example look-up table includes three columns, namely, a column for BLEP values; a column for ranges of SINR values; and a column for different MCSs. Another non-limiting example is a look-up table that includes a set of curves for the BLEP versus SINR, where each curve corresponds to a supported MCS that may be signaled back to the eNB as part of the CQI report. An example is shown in FIG. 3B which illustrates a graph of BLEP versus SINR values for a set of curves corresponding to different MCSs. The lookup tables in FIGS. 3 A and 3B are merely examples, and not intended to be limiting.

[0043] Such SINR to BLEP tables for the different MCSs may be obtained from extensive link level simulations by the UE modem vendor which reflect the performance of the UE for different MCSs. The table may include points down to fairly low BLEP values, including but not limited to the points only for 10% BLEP as is sufficient for the current LTE CQI schemes. The set curves (e.g. tabular values) for MCS may differ, for example, by one dB in performance which corresponds to certain quantization, i.e., corresponding to the SINR to CQI mapping.

[0044] It is noted that the UE measurement processing step can be done in a different order than described above and still achieve the same results. For example, mapping the SINR to CQI may be performed prior to determining the empirical X%-ile of the quantized values.

[0045] 4. CQI reporting and formatting: The UE reports CQI back to the eNB that includes an index that points to this MCS value.

[0046] The above-described steps allow, e.g., the eNB to transmit its small URLLC payload to the UE with the MCS corresponding to the latest received CQI from the UE, with ensuring that the experienced BLEP of the transmission will not exceed X%. This is assuming that the UE experienced channel quality is a wide sense stationary process, which maintains the same statistical properties for the observed NxM samples, also for the next short-term window counting for the time it takes for the UE to complete steps 3 and 4, as well as the potential eNB delays before the eNB schedule a new URLLC transmission to the UE, following the received CQI. [0047] Referring also to FIG. 4, this figure shows a simplified illustration of an example measurement procedure and processing in accordance with example embodiments. FIG. 4 includes a heatmap 302 showing the experienced channel quality (SINR) performed by a user equipment. Each block in the heatmap 302 corresponds to a radio resource and the different shaded regions in the heatmap 302 represent different values of SINR as indicated by legend 304. In this example, the user equipment measures SINR for NxM measurement samples as shown by arrows 306, 308. These samples are then processed, as shown by arrow 310, to create an empirical sample distribution 312. The UE then identifies the SINR at the outage value of X% from the empirical sample distribution 312 corresponding to SINR=SINR_outage which in FIG. 4 is represented by point 314. The identification of the outage value may be based on an internal lookup table of the UE.

[0048] According to some example embodiments, an eNB may configure a UE with a set of more than one BLEP constraints L = {X^/o, X₂ %,■■· , X_j%}, in which case the UE shall report not only an index to a single MCS as part of the CQI report, but indexes to MCS values corresponding to each of the BLEP constraints in the set £.

[0049] According some example embodiments, a UE may be configured to use the lowest, or Q-th lowest value (Q=1 ,2,3,. .. ,K) of K collected measurements when identifying the experienced channel quality (SINR) at the outage value of X% from the empirical sample distribution as described in step 3 above. The value of Q may be configured by the eNB as part of step 1 above. This may be particularly useful for cases where the number of K samples is insufficient to reliably determine the SINR value at the X% outage.

[0050] Using the example techniques above, the UE may report CQI that essentially corresponds to the X-percentile outage of the UE's experienced channel quality that expresses the MCS that the eNB shall use to fulfil latency requirements, such as the 5G URLCC requirements for example.

[0051] Referring now to FIG. 5, this figure shows an example operation and signaling procedure in accordance with example embodiments. At 402, the eNB (e.g. eNB 170) transmits an RRC configuration to the UE (e.g. UE 1 10) which includes at least one BLEP constraint and an indication of resources to be measured. In FIG. 5, the at least one BLEP constraint is denoted as a set £ = {X^/o, X₂ %,— , X_j%}, and the indication of resources is denoted N and M corresponding to N time-domain resources and M frequency domain resources to be measured, respectively. At 404, the UE collects a number, K, of channel quality measurement samples corresponding to the NxM radio resources. At 406, the UE sorts the measurement samples, and at 408 the UE reads each of the BLEP constraints to estimate a corresponding MCS. At 410, the UE transmits a set of the estimated MCSs to the eNB, namely, {MCS\ , MCSi, MCS_S } . The UE may be configured to repeat steps 404-406 if the UE is configured for periodic CQI reporting.

[0052] Referring now to FIG. 6, this figure illustrates another example message for configuring Channel Quality Indicator (CQI) reporting in accordance with example embodiments. At 502, the eNB (e.g. eNB 170) transmits an RRC configuration to the UE (e.g. UE 1 10) which includes a set of at least one value which is denoted Q = {Q\, Qi ,. .. ,(¾} , and indication of N time- domain resources and an indication of M frequency domain resources, respectively, to be measured by the UE. At 504, the UE performed channel measures over the time duration, N, and frequency resolution, M, to collect a number, K, of measurements. The UE only keeps the lowest Q\, Qi ,. .. ,Oj-th lowest values of the K collected measurements, and at step 506 estimates the corresponding MCS for each of the Q\, Qi ,. .. ,Oj-th lowest values. At 508, the UE transmits a set of the estimated MCSs to the eNB, namely, {MCS\, MCSi ,. .. , GSj} . The UE may be configured to repeat steps 504-506 if the UE is configured for periodic CQI reporting.

[0053] The eNB to UE RRC configuration is now further described with reference to a non- limiting 5G NR example. For this example, assume there is 15 kHz subcarrier spacing, a PRB size of 12 subcarriers, and mini-slot scheduling of 2 symbols (i.e. 0.14 ms TTI size). The gNB may configure the UE as follows: setting N=70, such that the UE shall collect measurements over a 10 ms interval in the time-domain (i.e. corresponding to 70 mini-slots). If the carrier bandwidth consists of 100 PRBs, the gNB could set M=100 or M=25 (i.e. using a subband resolution of 4 PRBs). This would result in: K=1750 for the case M=25 and K=7000 for the case M-100. Accordingly, the UE would base its CQI reporting on 1750 or 7000 measurement samples respectively. New CQI values could be reported with a periodicity different from the measurement interval, say e.g. every 5 ms as it is typically done in LTE.

[0054] Referring to FIG. 7, this figure shows a non-limiting example message 700 for configuring Channel Quality Indicator (CQI) reporting according to an example embodiment. The message 700 may be transmitted used by the eNB to configure the UE for CQI reporting. The message 700 in this example is a periodic CQI reporting message as defined in LTE Release 8 (i.e. 3GPPP 36.331 , "Radio resource control"), where the CQI is configured as part of the RRC configuration process (RRC Connection Setup or RRC Connection Reconfiguration). The underlined portion of the message 700 shows the additional information that may be used for configuring the UE for the CQI reporting. In this example, p is an INTEGER between 1 and 9 denoting the negative exponent of the target BLEP (e.g. p=l means 10^"1 and p=9 means 10^"9). The targetBLEP parameter may be used, for example, in the process described with reference to FIG. 5 above. Q is a sequence of integers between 1 and 99 which enables, for example, the process described with reference to FIG. 6 above. The N and M parameters in message 700 are the amount of time-domain and frequency-domain resources to be monitored, respectively. Thus, it will be appreciated that that although the message 700 includes parameters for both targetBLEP and Q this is not seen as limiting. For example, the message 700 may include targetBLEP and/or the Q parameter. Those skilled in the art will further appreciate that similar modifications for later LTE Releases and aperiodic CQI are similar.

[0055] As noted above, the UE sends a CQI report from the UE to eNB. This CQI may be included as part of the UE channel state information (CSI) report. For LTE, the CSI report is sent to the eNB in the LTE PUCCH. Different formats are defined to support normal or extended cyclic prefix, multiplexing or not with 1 or 2 - bit HARQ-ACK, etc. (see, e.g. 3GPP 36.213). New formats for supporting enhanced CQI may be defined. In LTE-A Release 10, the maximum length for the CSI report is 21 bits, corresponding to format 3 for TDD with up to 5 CCs. In Release 14, Format 4 and 5 have been defined with a larger message. Similarly, the support of enhanced CQI for URLLC requires a larger message size, and therefore a new format, since multiple CQI values may be reported in a single message.

[0056] In some examples, the processes described above may be applied for both periodic and aperiodic CQI feedback report. For cases with aperiodic feedback, the delay between the CQI request and CQI report can be reduced if the UE continuously monitors and collects channel quality measurements. Once the CQI request is received from the eNB, the UE may determine the CQI based on the N most recent measurements.

[0057] In some example, the recording window length N is configured to be large enough to provide a relatively good level of accuracy to the percentiles of interest. This is especially relevant for URLLC use cases, where information up to the 10^-5 percentile can be required. The recording window length can also be adjusted in accordance to the channel properties, e.g. coherence, variance, stationarity, etc. One challenge with this option is that many individual values are needed to have reliable measures of low percentiles, and sorting as such is an expensive operation. These issues may be addressed by using tree structures, and every time new individual values are available, they can be inserted, after removing any obsolete values. Pointers to all the individual values may be kept in a ring buffer to have pointers to obsolete values.

[0058] In another example, which does not require storing and sorting a large number of samples, a "biased" IIR filter is applied to each of the channel quality measurements y(t) as follows: l - f_up) ^■ E_b (t - 1) + f_up ^■ y(t) if (t)≥ E_b t

E_b (t) =

(1 ^_ fdown) ' E_b {t - 1) + f_down ^■ y(t) , if (t) < E_b {t where E_b (t) is the biased expectation of the channel quality at time instant t, and the f_up and fdown ^are configured by the eNB (i.e. included in the RRC configuration message previously presented). The ratio f_up/ fdown determines the bias of the filter: f_up = f_down corresponds to the typical IIR filter aiming at mean value estimation, heuristically matching some rather high percentile (the 50-percentile for symmetric and unimodal distributions, for example); whereas setting f_up < f_down bias the estimation towards lower percentiles of the distribution.

[0059] FIG. 8 is a logic flow diagram for enhanced Channel Quality Indicator (CQI) measurement procedure for URLLC. This figure further illustrates the operation of an exemplary method or methods, a result of execution of computer program instructions embodied on a computer readable memory, functions performed by logic implemented in hardware, and/or interconnected means for performing functions in accordance with exemplary embodiments. For instance, the feedback module 140-1 and/or 140-2 may include multiples ones of the blocks in FIG. 8, where each included block is an interconnected means for performing the function in the block. The blocks in FIG. 8 are assumed to be performed by the UE 110, e.g., under control of the feedback module 140-1 and/or 140-2 at least in part.

[0060] Referring to FIG. 8, in an example embodiment a method is provided comprising: performing, by a user equipment of a wireless network, a number of channel quality measurements according to a configuration received by the network, wherein the configuration is indicative of the number of channel quality measurements to be performed and comprises a set comprising at least one processing value, the at least one value comprising either an average block-error probability (BLEP) value or a measurement position as indicated by block 800; estimating a modulation and coding scheme (MCS) value for each processing value in the set based on the channel quality measurements as indicated by block 802; and transmitting, from the user equipment to a base station of the wireless network, an indication of the estimated MCS value as indicated by block 804.

[0061] The method may include generating, by the user equipment, a channel quality distribution based on the channel quality measurements.

[0062] The at least one processing value may include an average block-error probability (BLEP) value, and the estimating the MCS value may include: determining an outage value by comparing the BLEP value to the channel quality distribution; and mapping the outage value to the MCS value using a look-up table.

[0063] The at least one processing value may include an indication of a position, and wherein estimating the MCS value comprises: determining an order of the channel quality measurements; and estimating the MCS value for the channel quality measurement corresponding to the measurement position index.

[0064] The channel quality measurements are ordered from lowest to highest channel quality.

[0065] The configuration may include a number of time domain resources and an indication of the frequency domain partition.

[0066] The set may include two or more processing values, and the transmitting may include transmitting an indication of the estimated MCS value for each of the two or more processing values.

[0067] The configuration may be a radio resource control (RRC) configuration and performing the measurements may include at least one of: performing periodic channel quality measurements based on the RRC configuration; and performing aperiodic channel quality measurements based on the RRC configuration.

[0068] The channel quality measurements may be signal to interference and noise ratio (SINR) measurements.

[0069] In another example embodiment, an apparatus may include at least one processor; and at least one non-transitory memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform: performing, by a user equipment of a wireless network, a number of channel quality measurements according to a configuration received by the network, wherein the configuration is indicative of the number of channel quality measurements to be performed and comprises a set comprising at least one processing value, the at least one value comprising either an average block-error probability (BLEP) value or a measurement position index; estimating a modulation and coding scheme (MCS) value for each processing value in the set based on the channel quality measurements; and transmitting, from the user equipment to a base station of the wireless network, an indication of the estimated MCS value.

[0070] The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to perform: generating, by the user equipment, a channel quality distribution based on the channel quality measurements.

[0071] The at least one processing value may include an average block-error probability (BLEP) value, and the estimating the MCS value may include: determining an outage value by comparing the BLEP value to the channel quality distribution; and mapping the outage value to the MCS value using a look-up table.

[0072] The at least one processing value may include an indication of a position, and wherein estimating the MCS value comprises: determining an order of the channel quality measurements; and estimating the MCS value for the channel quality measurement corresponding to the measurement position index.

[0073] The channel quality measurements are ordered from lowest to highest channel quality.

[0074] The configuration may include a number of time domain resources and an indication of the frequency domain partition.

[0075] The set may include two or more processing values, and the transmitting may include transmitting an indication of the estimated MCS value for each of the two or more processing values.

[0076] The configuration may be a radio resource control (RRC) configuration and performing the measurements may include at least one of: performing periodic channel quality measurements based on the RRC configuration; and performing aperiodic channel quality measurements based on the RRC configuration.

[0077] The channel quality measurements may be signal to interference and noise ratio (SINR) measurements. [0078] A user equipment may comprise an apparatus according to any one of paragraphs [0069]-[0077].

[0079] According to another embodiment an apparatus may comprise: means for performing, by a user equipment of a wireless network, a number of channel quality measurements according to a configuration received by the network, wherein the configuration is indicative of the number of channel quality measurements to be performed and comprises a set comprising at least one processing value, the at least one value comprising either an average block-error probability (BLEP) value or a measurement position index; means for estimating a modulation and coding scheme (MCS) value for each processing value in the set based on the channel quality measurements; and means for transmitting, from the user equipment to a base station of the wireless network, an indication of the estimated MCS value.

[0080] FIG. 9 is a logic flow diagram for enhanced Channel Quality Indicator (CQI) measurement procedure for URLLC. This figure further illustrates the operation of an exemplary method or methods, a result of execution of computer program instructions embodied on a computer readable memory, functions performed by logic implemented in hardware, and/or interconnected means for performing functions in accordance with exemplary embodiments. For instance, the an adaptation module 150-1 and/or 150-2 may include multiples ones of the blocks in FIG. 9, where each included block is an interconnected means for performing the function in the block. The blocks in FIG. 9 are assumed to be performed by a base station such as eNB 170, e.g., under control of the adaptation module 150-1 and/or 150- 2 at least in part.

[0081] Referring to FIG. 9, in an example embodiment a method is provided comprising: determining, by a base station of a wireless network, a configuration for a number of channel quality measurements to be performed by a user equipment for determining a modulation and coding scheme (MCS), configuration is indicative of the number of channel quality measurements to be performed and comprises a set comprising at least one processing value, the at least one value comprising either an average block-error probability (BLEP) value or a measurement position as indicated by block 900; transmitting, from the base station to the user equipment, the configuration as indicated by block 902; and receiving, from the user equipment, an indication of the estimated MCS value for each processing value in the set as indicated by block 904.

[0082] The set may include one or more average block-error probability (BLEP) values. [0083] The set may comprise one or more measurement position indexes.

[0084] The configuration may include a number of time domain resources and an indication of the frequency domain partition.

[0085] The configuration may be a radio resource control (R C) configuration and indicates whether the channel quality measurements are either periodic or aperiodic.

[0086] The method may comprise selecting one of the estimated MCS values indicated by the user equipment to be used for a downlink transmission; and transmitting the downlink transmission to the user equipment based on the selected MCS value.

[0087] The selecting the estimated MCS value may be based on a latency requirement of the wireless network.

[0088] According to another example embodiment, an apparatus may comprise: at least one processor; and at least one non-transitory memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform: determining, by a base station of a wireless network, a configuration for a number of channel quality measurements to be performed by a user equipment for determining a modulation and coding scheme (MCS), wherein the configuration comprises at least an indication of the number of channel quality measurements to be performed and a set comprising at least one processing value; transmitting, from the base station to the user equipment, the configuration; and receiving, from the user equipment, an indication of the estimated MCS value for each processing value in the set.

[0089] The set may include one or more average block-error probability (BLEP) values.

[0090] The set may comprise one or more measurement position indexes.

[0091] The configuration may include a number of time domain resources and an indication of the frequency domain partition.

[0092] The configuration may be a radio resource control (RRC) configuration and indicates whether the channel quality measurements are either periodic or aperiodic.

[0093] The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus at least to perform may comprise selecting one of the estimated MCS values indicated by the user equipment to be used for a downlink transmission; and transmitting the downlink transmission to the user equipment based on the selected MCS value.

[0094] The selecting the estimated MCS value may be based on a latency requirement of the wireless network.

[0095] A base station may comprise an apparatus according to any one of paragraphs [0088]- [0094].

[0096] According to yet another embodiment, an apparatus may comprise: means for determining, by a base station of a wireless network, a configuration for a number of channel quality measurements to be performed by a user equipment for determining a modulation and coding scheme (MCS), wherein the configuration comprises at least an indication of the number of channel quality measurements to be performed and a set comprising at least one processing value; means for transmitting, from the base station to the user equipment, the configuration; and means for receiving, from the user equipment, an indication of the estimated MCS value for each processing value in the set.

[0097] A communication system may include an apparatus in accordance with any one of the paragraphs [0069]-[0077] and an apparatus in accordance with any one of paragraphs [0088]- [0094].

[0098] A computer program may include program code for executing the method according to any of paragraphs [0060]-[0068] or [0081]-[0087]. The computer program may be a computer program product comprising a computer-readable medium bearing computer program code embodied therein for use with a computer.

[0099] Without in any way limiting the scope, interpretation, or application of the claims appearing below, a technical effect of one or more of the example embodiments disclosed herein is to address the challenges of LA for URLLC traffic, where the sporadic transmission of small packets leads to rapidly changing interference difficult to be tracked at the eNB side. At the same time, the multiple CQI indexes (each with a different associated BLEP constraint) reported to the eNB allow to perform spectral-efficient link adaptation, as the BLEP can be flexibly adjusted in accordance to the latency and reliability constraint of each individual URLLC packet. Another technical effect of one or more of the example embodiments disclosed herein is to help meet URLLC requirements in challenging environments with rapid interference fluctuations. Another technical effect of one or more of the example embodiments disclosed herein is that, for each BLEP constraint, only one CQI value is reported. This results in a lower uplink feedback overhead as compared to some LTE CQI reporting configurations where the CQI is reported on a per-subband basis.

[0100] Embodiments herein may be implemented in software (executed by one or more processors), hardware (e.g., an application specific integrated circuit), or a combination of software and hardware. In an example embodiment, the software (e.g., application logic, an instruction set) is maintained on any one of various conventional computer-readable media. In the context of this document, a "computer-readable medium" may be any media or means that can contain, store, communicate, propagate or transport the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer, with one example of a computer described and depicted, e.g., in FIG. 1. A computer-readable medium may comprise a computer-readable storage medium (e.g., memories 125, 155, 171 or other device) that may be any media or means that can contain, store, and/or transport the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer. A computer-readable storage medium does not comprise propagating signals.

[0101] If desired, the different functions discussed herein may be performed in a different order and/or concurrently with each other. Furthermore, if desired, one or more of the above- described functions may be optional or may be combined.

[0102] Although various aspects of the invention are set out in the independent claims, other aspects of the invention comprise other combinations of features from the described embodiments and/or the dependent claims with the features of the independent claims, and not solely the combinations explicitly set out in the claims.

[0103] It is also noted herein that while the above describes example embodiments of the invention, these descriptions should not be viewed in a limiting sense. Rather, there are several variations and modifications which may be made without departing from the scope of the present invention as defined in the appended claims.

[0104] The following abbreviations that may be found in the specification and/or the drawing figures are defined as follows:

3 GPP 3^rd generation partnership project

BLER Block error rate BLEP Block error probability

CC Component Carrier

CDF Cumulative distribution function

CQI Channel quality indicator

eNB (or eNodeB) evolved Node B (e.g., an LTE base station)

HARQ Hybrid automatic repeat request

I/F interface

LA Link adaptation

LTE Long term evolution

MCS Modulation and coding scheme

MME mobility management entity

NCE network control element

N/W network

PRB Physical resource block

RRH remote radio head

Rx receiver

SGW serving gateway

SINR Signal to interference and noise ratio

Tx transmitter

QoS Quality of service

UE user equipment (e.g., a wireless, typically mobile device)

URLLC Ultra-reliable low-latency communication

Claims

1. A method, comprising: performing, by a user equipment of a wireless network, a number of channel quality measurements according to a configuration received by the network, wherein the configuration is indicative of the number of channel quality measurements to be performed and comprises a set comprising at least one processing value, the at least one value comprising either an average block-error probability (BLEP) value or a

measurement position index; estimating a modulation and coding scheme (MCS) value for each processing value in the set based on the channel quality measurements; and transmitting, from the user equipment to a base station of the wireless network, an indication of the estimated MCS value.

2. The method as in claim 1, further comprising: generating, by the user equipment, a channel quality distribution based on the channel quality measurements.

3. The method as in claim 2, wherein the at least one processing value comprises an

average block-error probability (BLEP) value, and wherein estimating the MCS value comprises: determining an outage value by comparing the BLEP value to the channel quality distribution; and mapping the outage value to the MCS value using a look-up table.

4. The method as in claim 1, wherein the at least one processing value comprises an

indication of a position, and wherein estimating the MCS value comprises: determining an order of the channel quality measurements; and estimating the MCS value for the channel quality measurement corresponding to the measurement position index.

5. The method as in claim 4, wherein the channel quality measurements are ordered from lowest to highest channel quality.

6. The method as in any one of claims 1-5, wherein the configuration comprises a number of time domain resources and an indication of the frequency domain partition.

7. The method as in any one of claims 1-6, wherein the set comprises two or more

processing values, and wherein the transmitting comprises transmitting an indication of the estimated MCS value for each of the two or more processing values.

8. The method as in any one of claims 1-7, wherein the configuration is a radio resource control (R C) configuration and wherein performing the measurements comprises at least one of: performing periodic channel quality measurements based on the RRC configuration; and performing aperiodic channel quality measurements based on the RRC configuration.

9. The method of claim 1-8, wherein the channel quality measurements are signal to

interference and noise ratio (SINR) measurements.

10. An apparatus comprising: at least one processor; and at least one non-transitory memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform: performing, by a user equipment of a wireless network, a number of channel quality measurements according to a configuration received by the network, wherein the configuration is indicative of the number of channel quality measurements to be performed and comprises a set comprising at least one processing value, the at least one value comprising either an average block-error probability (BLEP) value or a measurement position index; estimating a modulation and coding scheme (MCS) value for each processing value in the set based on the channel quality measurements; and transmitting, from the user equipment to a base station of the wireless network, an indication of the estimated MCS value.

11. The apparatus as in claim 10, wherein the at least one memory and the computer

program code are configured to, with the at least one processor, cause the apparatus at least to perform: generating, by the user equipment, a channel quality distribution based on the channel quality measurements.

12. The apparatus as in claim 11, wherein the at least one processing value comprises an average block-error probability (BLEP) value, and wherein estimating the MCS value comprises: determining an outage value by comparing the BLEP value to the channel quality distribution; and mapping the outage value to the MCS value using a look-up table.

13. The apparatus as in claim 10, wherein the at least one processing value comprises an indication of a position, and wherein estimating the MCS value comprises: determining an order of the channel quality measurements; and estimating the MCS value for the channel quality measurement corresponding to the measurement position index.

14. The apparatus as in claim 13, wherein the channel quality measurements are ordered from lowest to highest channel quality.

15. The apparatus as in any one of claims 10-14, wherein the configuration comprises a number of time domain resources and an indication of the frequency domain partition.

16. The apparatus as in any one of claims 10-15, wherein the set comprises two or more processing values, and wherein the transmitting comprises transmitting an indication of the estimated MCS value for each of the two or more processing values.

17. The apparatus as in any one of claims 10-16, wherein the configuration is a radio

resource control (R C) configuration and wherein performing the measurements comprises at least one of: performing periodic channel quality measurements based on the RRC configuration; and performing aperiodic channel quality measurements based on the RRC configuration.

18. The apparatus of claim 10, wherein the channel quality measurements are signal to

interference and noise ratio (SINR) measurements.

19. A user equipment comprising an apparatus as in any one of claims 10 to 18.

20. An apparatus, comprising: means for performing, by a user equipment of a wireless network, a number of channel quality measurements according to a configuration received by the network, wherein the configuration is indicative of the number of channel quality measurements to be performed and comprises a set comprising at least one processing value, the at least one value comprising either an average block-error probability (BLEP) value or a measurement position index; means for estimating a modulation and coding scheme (MCS) value for each processing value in the set based on the channel quality measurements; and means for transmitting, from the user equipment to a base station of the wireless network, an indication of the estimated MCS value.

21. The apparatus as in claim 20, further comprising means for performing a method as in any one of claims 2 to 8.

22. A method comprising: determining, by a base station of a wireless network, a configuration for a number of channel quality measurements to be performed by a user equipment for determining a modulation and coding scheme (MCS), wherein the configuration comprises at least an indication of the number of channel quality measurements to be performed and a set comprising at least one processing value; transmitting the configuration from the base station to the user equipment; and receiving, from the user equipment, an indication of the estimated MCS value for each processing value in the set.

23. The method as in claim 22, wherein the set comprises one or more average block-error probability (BLEP) values.

24. The method as in any one of claims 22-23, wherein the set comprises one or more

measurement position indexes.

25. The method as in any one of claims 22-24, wherein the configuration comprises a

number of time domain resources and an indication of the frequency domain partition.

26. The method as in any one of claims 22-25, wherein the configuration is a radio resource control (RRC) configuration and indicates whether the channel quality measurements are either periodic or aperiodic.

27. The method as in any one of claims 22-26, further comprising: selecting one of the estimated MCS values indicated by the user equipment to be used for a downlink transmission; and transmitting the downlink transmission to the user equipment based on the selected MCS value.

28. The method as in claim 27, wherein selecting the estimated MCS value is based on a latency requirement of the wireless network.

29. An apparatus comprising: at least one processor; and at least one non-transitory memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform: determining, by a base station of a wireless network, a configuration for a number of channel quality measurements to be performed by a user equipment for determining a modulation and coding scheme (MCS), wherein the configuration comprises at least an indication of the number of channel quality measurements to be performed and a set comprising at least one processing value; transmitting, from the base station to the user equipment, the configuration; and receiving, from the user equipment, an indication of the estimated MCS value for each processing value in the set.

30. The apparatus as in claim 29, wherein the set comprises one or more average block-error probability (BLEP) values.

31. The apparatus as in any one of claims 29-30, wherein the set comprises one or more measurement position indexes.

32. The apparatus as in any one of claims 29-31, wherein the configuration comprises a number of time domain resources and an indication of the frequency domain partition.

33. The apparatus as in any one of claims 29-32, wherein the configuration is a radio

resource control (R C) configuration and indicates whether the channel quality measurements are either periodic or aperiodic.

34. The apparatus as in any one of claims 29-33, wherein the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform: selecting one of the estimated MCS values indicated by the user equipment to be used for a downlink transmission; and transmitting the downlink transmission to the user equipment based on the selected MCS value.

35. The apparatus as in claim 34, wherein selecting the estimated MCS value is based on a latency requirement of the wireless network.

36. A base station comprising an apparatus as in any one of claims 29 to 35.

37. An apparatus, comprising: means for determining, by a base station of a wireless network, a configuration for a number of channel quality measurements to be performed by a user equipment for determining a modulation and coding scheme (MCS), wherein the configuration comprises at least an indication of the number of channel quality measurements to be performed and a set comprising at least one processing value; means for transmitting, from the base station to the user equipment, the configuration; and means for receiving, from the user equipment, an indication of the estimated MCS value for each processing value in the set.

38. The apparatus as in claim 37, further comprising means for performing a method as in any one of claims 23 to 28.

39. A communication system comprising an apparatus in accordance with any one of the claims 10 to 19 and an apparatus in accordance with any one of the claims 29 to 36.

40. A computer program comprising program code for executing the method as in any of claims 1-9 or claims 22 to 28.

41. The computer program according to claim 40, wherein the computer program is a computer program product comprising a computer-readable medium bearing computer program code embodied therein for use with a computer.