Patent Description:
In Third Generation Partnership Project (3GPP) Technical Specification (TS) <NUM>, the Channel Quality Index (CQI) definition is given. For a User Equipment device (UE), based on an observation interval in time, and an observation interval in frequency, the User Equipment device (UE) shall derive, for each CQI value reported in uplink subframe, the highest CQI index which satisfies the following condition, or CQI index <NUM> if CQI index <NUM> does not satisfy the condition:.

The CSI reference resource for a serving cell is defined as follows:.

In the CSI reference resource, for the purpose of deriving the CQI index, the UE shall make some assumption about the control channel configuration, numerology (e.g., Cyclic Prefix (CP) length and subcarrier spacing) for PDSCH reception, resource elements used by primary or secondary synchronization signals or Physical Broadcast Channel (PBCH), redundancy version, the ratio of PDSCH Energy Per Resource Element (EPRE) to CSI Reference Signal (CSI-RS) EPRE, Resource Elements (REs) used for CSI-RS and zero-power CSI-RS and the PDSCH transmission format, etc. For example, in New Radio (NR) specification R1-<NUM>, the UE shall assume the following for the purpose of deriving the CQI index:.

In 3GPP TS <NUM> or 3GPP TS <NUM>, one example CQI table is defined as Table <NUM>. In this CQI table, the CQI index indicates a combination of modulation scheme and transport block size corresponding to a single PDSCH transport block.

The UE shall assume the PDSCH DMRS being mapped to physical resources according to type <NUM> or type <NUM> as given by the higher-layer parameter DL-DMRS-config-type.

The UE shall assume the sequence r(m) is mapped to physical resource elements according to <MAT> <MAT> <MAT> <MAT> where wf(k'), wt(l'), and Δ are given by Tables <NUM>. <NUM>-<NUM> and <NUM>. <NUM>-<NUM>.

For briefing, for RE set occupied by DMRS with k' = <NUM>, it is named as "comb0" and for RE set occupied by DMRS with k' = <NUM>, it is named as "comb1".

The reference point for l and the position l<NUM> of the first DMRS symbol depends on the mapping type:.

The position(s) of additional DMRS symbols is given by l and the last OFDM symbol used for PDSCH in the slot according to Tables <NUM>. <NUM>-<NUM> and <NUM>. <NUM>-<NUM>.

The time-domain index l' and the supported antenna ports p depend on DL-DMRS-len according to Table <NUM>. <NUM>-<NUM>.

As one example of DL-DMRS-len = <NUM>, DL-DMRS-add-pos = <NUM> and DL-DMRS-config-type = <NUM>, the DMRS pattern can be shown as <FIG>.

As another example, DL-DMRS-len = <NUM>, DL-DMRS-add-pos = <NUM> and DL-DMRS-config-type = <NUM>, the DMRS pattern can be shown as <FIG>.

In 3GPP TS <NUM>, the PTRS definition is given. The UE shall assume phase-tracking reference signals being present only in the resource blocks used for the PDSCH, and only if the higher-layer parameter DL-PTRS-present indicates phase-tracking reference signals being used.

If present, the UE shall assume the PDSCH PTRS being mapped to physical resources according to <MAT> <MAT> <MAT> in every KPTRS of the scheduled resource blocks, starting with the lowest numbered resource block scheduled when the following conditions are fulfilled.

As one example, when KPTRS = <NUM> and LPTRS = <NUM>, the PTRS pattern is illustrated as shown in <FIG>.

In 3GPP TS <NUM>, the procedure for the PTRS usage is given.

If a UE is configured with the higher parameter DL-PTRS-present and if the additional higher layer parameters DL-PTRS-time-density and DL-PTRS-frequency-density are configured, the UE may assume the PTRS antenna ports' presence and pattern are a function of the corresponding scheduled MCS and scheduled bandwidth as shown in Table <NUM> and Table <NUM>, otherwise the UE may assume that PTRS is present in every OFDM symbol and in every second Physical Resource Block (PRB).

An additional prior art example is disclosed by the patent application <CIT>.

Systems and methods are disclosed herein for providing a new Channel State Information (CSI) reference resource definition for CSI reports in a cellular communications network such as, e.g., New Radio (NR). The invention is defined by the independent claims, preferred embodiments are covered by the dependent claims.

Some examples of a radio access node include, but are not limited to, a base station (e.g., a New Radio (NR) Node B (gNB) in a Third Generation Partnership Project (3GPP) Fifth Generation (<NUM>) NR network or an enhanced or evolved Node B (eNB) in a 3GPP Long Term Evolution (LTE) network), a high-power or macro base station, a low-power base station (e.g., a micro base station, a pico base station, a home eNB, or the like), and a relay node.

Some examples of a wireless device include, but are not limited to, a User Equipment (UE) in a 3GPP network and a Machine Type Communication (MTC) device.

Note that, in the description herein, reference may be made to the term "cell;" however, particularly with respect to <NUM> NR concepts, beams may be used instead of cells and, as such, it is important to note that the concepts described herein are equally applicable to both cells and beams.

There currently exist certain challenge(s) present with existing solutions. As shown above, the current CQI definition is associated with the CSI reference resource. The overhead for the CSI reference resource is pre-known when UE derives the CQI value. For a single PDSCH transport block with a combination of modulation scheme and transport block size corresponding to the CQI index, when the same number of REs as the CSI reference resource is used for this PDSCH transmission, the Block Error Rate (BLER) is expected to be not exceeding a given threshold.

However, in current NR, the overhead for the CSI reference resource may be NOT pre-known. If the overhead is not pre-known, the gNB and UE may obtain different Transport Block Size (TBS) based on the same spectral efficiency. Thus, it will lead to some misunderstanding for the gNB for the reported CQI. There are two factors which lead to the problem.

The first factor is the overhead for the PDSCH transmission may change dynamically. According to current RAN1 discussion, the DMRS overhead may be dynamically changed. For example, for Single User Multiple Input Multiple Output (SU-MIMO) and when two layers are configured, two mapping methods can be used for the DMRS port mapping to the comb. In the first mapping method, two ports are mapped into the same comb. In the second mapping method, two ports are mapped into different combs. Which mapping method is used may be indicated dynamically by Downlink Control Information (DCI). As one example shown in <FIG>, when the first mapping method is used, only REs marked with cross hatching are used for DMRS two-layer transmission, when the second mapping method is used, REs marked with cross hatching will be used for one-layer DMRS transmission, and REs marked with diagonal hatching will be used for the other layer DMRS transmissions. The overhead for the second mapping method is larger than that with the first mapping method.

The second factor is that the overhead for PDSCH transmission is associated with the CQI feedback itself. As shown in Table <NUM>, the time density of PTRS is a function of scheduled MCS. As one example, when one CQI index is derived, when the corresponding MCS is larger than ptrs-MCS3, LPT-RS = <NUM>, the PTRS pattern corresponds to the left pattern indicated in <FIG>. When the corresponding MCS is smaller than ptrs-MCS3 and larger than ptrs-MCS2, LPT-RS = <NUM>, the PTRS pattern corresponds to the right pattern indicated in <FIG>. For different derived MCS, the RS overhead is different. If the gNB and UE have different assumptions on the overhead, the MCS may be not accurate.

Certain aspects of the present disclosure and their embodiments may provide solutions to the aforementioned or other challenges. The present disclosure sets forth the following key proposals:.

There are, proposed herein, various embodiments which address one or more of the issues disclosed herein.

Certain embodiments may provide one or more of the following technical advantage(s). The advantages of the present disclosure are:.

<FIG> illustrates one example of a cellular communications network <NUM> according to some embodiments of the present disclosure. In the embodiments described herein, the cellular communications network <NUM> is a <NUM> NR network. In this example, the cellular communications network <NUM> includes base stations <NUM>-<NUM> and <NUM>-<NUM>, which in <NUM> NR are referred to as gNBs, controlling corresponding macro cells <NUM>-<NUM> and <NUM>-<NUM>. The base stations <NUM>-<NUM> and <NUM>-<NUM> are generally referred to herein collectively as base stations <NUM> and individually as base station <NUM>, and may also be referred to herein as radio access node <NUM>. Likewise, the macro cells <NUM>-<NUM> and <NUM>-<NUM> are generally referred to herein collectively as macro cells <NUM> and individually as macro cell <NUM>. The cellular communications network <NUM> may also include a number of low power nodes <NUM>-<NUM> through <NUM>-<NUM> controlling corresponding small cells <NUM>-<NUM> through <NUM>-<NUM>. The low power nodes <NUM>-<NUM> through <NUM>-<NUM> can be small base stations (such as pico or femto base stations) or Remote Radio Heads (RRHs), or the like. Notably, while not illustrated, one or more of the small cells <NUM>-<NUM> through <NUM>-<NUM> may alternatively be provided by the base stations <NUM>. The low power nodes <NUM>-<NUM> through <NUM>-<NUM> are generally referred to herein collectively as low power nodes <NUM> and individually as low power node <NUM>. Likewise, the small cells <NUM>-<NUM> through <NUM>-<NUM> are generally referred to herein collectively as small cells <NUM> and individually as small cell <NUM>. The base stations <NUM> (and optionally the low power nodes <NUM>) are connected to a core network <NUM>.

Exemplary methods for PTRS handling according to embodiments disclosed herein are now discussed. In the first embodiments, PTRS density in CSI reference resource is associated with the selected CQI value. As the first further embodiment, PTRS time density according to the MCS thresholds in DL-PTRS-time-density is assumed, where the ptrs-MCS thresholds are mapped to CQI thresholds. The mapping is high layer configured, or predefined or determined by a predefined rule. As one example, ptrs-MCS1, ptrs-MCS2, ptrs-MCS3, ptrs-MCS4 may be mapped to CQI1, CQI2, CQ3, CQI4 according to Table <NUM>. Thus, the time density of PTRS in the CSI reference resource can be given by Table <NUM>.

In some embodiments, the CQI table comprises <NUM> entries while the MCS table comprises <NUM> entries. The MCS table may be constructed such that the entries <NUM>-<NUM> in the CQI table are comprised in the MCS table as well (i.e., there are corresponding entries in the MCS table with the same target code rate and modulation). In that case, in an embodiment, the ptrs-MCS value is implicitly mapped to the corresponding CQI value with the same code rate and modulation, if such an entry exists, or, if such an entry does not exist, the CQI value corresponding to the closest MCS value to ptrs-MCS is used for the mapping.

As a second further embodiment of the first embodiment, the CQI index thresholds are configured by higher layer signaling for the PTRS density assumption in the CSI reference resource. According to this embodiment, the gNB can directly signal the information included in Table <NUM> to the terminal.

As a third further embodiment of the first embodiment, the association of the CQI value to the PTRS density is directly configured in the CQI feedback table. One example is given as Table <NUM> where the time density the UE shall assume in CQI calculation is indicated in the table; if PTRS is configured for downlink transmission, then the UE shall use this overhead, otherwise the UE shall ignore this overhead when computing CQI. In this example, only the time density is adapted, while the frequency density can be assumed to be fixed overhead, e.g., every second Resource Block (RB), KPTRS=<NUM>.

As a fourth further embodiment of the first embodiment, the association of PTRS density to the CQl-value is defined according to a predefined rule. As one example for the predefined rule, the PTRS density is determined by the MCS value whose corresponding spectrum efficiency, after PTRS overhead is considered, is closest to the spectrum efficiency related to derived CQI value. One example procedure is illustrated in <FIG>. To obtain the PTRS density of CSI reference resource, we can first get the MCS value whose corresponding spectrum efficiency, after PTRS overhead is considered, is closest to the spectrum efficiency related to derived CQI value, the MCS values can be given by: <MAT> where f<NUM>(·), f<NUM>(·), f<NUM>(·) is function, and then set PTRS density in the CSI reference resource for CQIindex as the PTRS density associated with <MAT>.

As one example of f<NUM>(IMCSk, CQIindex), it can be taken as the spectrum efficiency given IMCSk, CQIindex and other related parameters, such as the number of layers, the scheduled resource, accounts for overhead from CSI-RS, CORESET, etc..

As one example function for the f<NUM>(·) can be: <MAT> where QCQIindex is the number of bits corresponding to the modulation indicated by CQI index. For example, when 16QAM is indicated, QCQIindex = <NUM>. RCQIindex is the efficient coding rate indicated by CQI index, and v is the number of layers. f<NUM>(CQIindex) can be taken as the efficiency indicated by the CQI index.

As one example for f<NUM>(f<NUM>(·),f<NUM>(·)), it can be given by: <MAT>.

As one example procedure, it can include one or more of the following steps:.

In Step <NUM>, the "intermediate" number of information bits can be given by NRE · v · Qm · R where.

As another alternative for the Step <NUM> and Step <NUM>, the spectrum efficiency is approximated by <MAT> where.

In the second embodiment, in CSI reference resource, PTRS density is assumed as the first PTRS density when DL-PTRS-time-density and DL-PTRS-frequency-density are configured by RRC and is assumed as the second PTRS density when DL-PTRS-time-density and DL-PTRS-frequency-density are not configured. In the second embodiment, the first PTRS density may be the same as the second PTRS density. As one example for the first PTRS density, it can be assumed as L_PTRS=<NUM> and K_PTRS=<NUM> when DL-PTRS-time-density and DL-PTRS-frequency-density are configured by RRC. As one example for the second PTRS density, PTRS is assumed to be present in every OFDM symbol and every second PRB, as what is the default case if DL-PTRS-time-density and DL-PTRS-frequency-density is not configured. If DL-PTRS-present is not configured, the UE assumes that no resource elements in the CSI reference resource are used for PTRS.

<FIG> illustrates the operation of a radio access node <NUM> and a wireless device <NUM> according to at least some of the embodiments described above. Note that this process is equally applicable to the low power node <NUM>. Optional steps are represented by dashed lines. As illustrated, the radio access node <NUM> optionally configures one or more, but preferably multiple, PTRS patterns and/or density to CQI index associations for the wireless device <NUM> (step <NUM>). In some embodiments, this is done via RRC configuration, but is not limited thereto.

The wireless device <NUM> derives (e.g., selects) a CQI index to report for a CSI reference resource, where the CQI index is associated with a PTRS density and/or pattern within the CSI reference resource (step <NUM>). In some embodiments, known associations between multiple CQI index values and PTRS densities and/or patterns for those CQI index values are used by the wireless device <NUM> when selecting the CQI index to report to the radio access node <NUM>. For example, the CQI index derivation procedure may take into account overhead in the CSI reference resource, where this overhead includes PTRS and the PTRS density and/or the pattern in the CSI reference resource varies between CQI index values. For any particular CQI index, the overhead due to PTRS can be determined based on the associated PTRS density and/or pattern.

The association between the CQI index and the PTRS density and/or pattern may be determined, e.g., in accordance with any of the embodiments described above. For example, in some embodiments, the association between the CQI index and the PTRS density and/or pattern is predefined, e.g., via an appropriate standard. In some other embodiments, the association between the CQI index and the PTRS density and/or pattern is configured, e.g., via a network node such as, e.g., the radio access node <NUM>. In some other embodiments, the association between the CQI index and the PTRS density and/or pattern is determined by the wireless device <NUM> based on one or more predefined rules, e.g., as described above with respect to <FIG>.

The wireless device <NUM> reports the derived CQI index to the radio access node <NUM>, where again the CQI index is associated with the corresponding PTRS density and/pattern (step <NUM>). The association between the CQI index and the PTRS density and/or pattern is known or can be determined by the radio access node <NUM>. In this manner, the radio access node <NUM> and the wireless device <NUM> have a common understanding of the PTRS density and/or pattern in the CSI reference resource. Optionally, the radio access node <NUM> utilizes the reported CQI index and potentially the associated PTRS pattern and/or density for one or more operational tasks (e.g., MCS selection for a downlink grant to the wireless device <NUM>) (step <NUM>).

Exemplary methods for DMRS handling in the CSI reference resource according to some embodiments disclosed herein are now discussed. Note that these methods for DMRS handling in the CSI reference resource may, in some embodiments, be combinable with the methods for PTRS handling described above.

In one embodiment, the UE-specific reference signal overhead in the CSI reference resource is consistent with one or more of:.

When the UE-specific reference signal overhead in the CSI reference resource is consistent with the number of additional DMRS symbols, it can be aligned with the higher layer configured additional DMRS symbols for PDSCH transmission, and/or it can also use separate signaling to configure the number of additional DMRS symbols in the CSI reference resource. When it is configured by high layer signaling, the UE may assume that the number of higher layer configured additional DMRS symbols are taken into account in the CSI reference resource. It can also be predefined. For example, as default, only one front-loaded OFDM symbol is assumed in the CSI reference resource. As one example for the predefined rule, the UE assumes a single symbol front loaded DMRS symbol for RI=<NUM>-<NUM> and two symbol front loaded DMRS symbols for RI=<NUM>-<NUM>. It can also be determined by predefined rule. The rule can be aligned with the DMRS symbols determination for actual PDSCH transmission.

When the UE-specific reference signal overhead in the CSI reference resource is consistent with DMRS configuration types, it can be aligned with the RRC configured for actual used DMRS in PDSCH transmission, and/or it can also be configured by separate RRC signaling for the DMRS configuration type used in CSI reference resource, and it can also be predefined.

When the UE-specific reference signal overhead in the CSI reference resource is consistent with the DMRS pattern, it can be one or more of the following:.

When the DMRS pattern is aligned with which is indicated in the latest received downlink control indicator, it includes that the overhead assumption for the latest PDSCH transmission can be assumed to be the overhead assumption in the CSI reference resource. As one example, when RI=<NUM>, the overhead for DMRS is assumed to be equal to one "comb" if the antenna ports are mapping into only one "comb" in the latest received downlink control indicator, and the overhead for DMRS is assumed to be equal to two "comb" if the antenna ports are mapping into two "comb. " It can be predefined, RRC configured, or determined according to predefined rule to decide the pattern. If it is predefined, the DMRS pattern is fixed regardless of the DCI scheduling. If it is RRC configured, the DMRS pattern in CSI reference resource is decided according to RRC configuration. If a predefined rule, the DMRS pattern can be derived based on the rule. As one example of the rule, the DMRS pattern used for SU-MIMO is also applied to Multi User Multiple Input Multiple Output (MU-MIMO) cases.

When the most recent reported rank is changed, and there are no reference DMRS patterns, the DMRS pattern may be configured by RRC signaling, predefined, or determined according to a predefined rule. As one example of a predefined rule, the layer mapping to comb(s) in the latest received downlink control indicator can be used for any rank.

When the UE-specific reference signal overhead in the CSI reference resource is consistent with the number of OFDM symbols in the CSI reference resource, it can be the number of OFDM symbols used in the corresponding valid downlink subframe related to the CSI reference resource. It can also be configured by RRC signaling. It can also be predefined or determined according to a predefined rule. In some embodiments, the number of OFDM symbols in the CSI reference resource is RRC configured for each CSI report setting, i.e. it is part of the ReportConfig IE. This allows the gNB to dynamically change the CSI reference resource assumption used by the UE for CQI calculation, by triggering different aperiodic CSI reports. For instance, one CSI report setting may use all OFDM symbols in the slot as the CSI reference resource while another CSI report setting may use a smaller number of OFDM symbols, such as four symbols. Such a configuration may be appropriate if the gNB intends to schedule the UE with non-slot based scheduling.

The wireless device <NUM> derives (e.g., selects) a CQI index to report for a CSI reference resource (step <NUM>). In other words, as will be appreciated by one of skill in the art, the wireless device <NUM> derives the CQI index (desired modulation and coding scheme) assuming a hypothetical PDSCH transmission on a (also hypothetical) CSI reference resource. In some embodiments, the CQI index is associated with a PTRS density and/or pattern within the CSI reference resource, as described above. Further, in this embodiment, a UE-specific reference signal (e.g., DMRS) overhead in the CSI reference resource is consistent with one or more parameters (e.g., the most recent reported rank for the CSI report setting (i.e., CSI process in LTE terminology), the number of additional DMRS symbols, the DMRS configuration type(s), DMRS pattern(s), reserved resources configured for the wireless device <NUM>, the number of OFDM symbols in the CSI reference resource, and/or semi-statically configured slot format(s)), as described above, and is used by the wireless device <NUM> when selecting the CQI index to report to the radio access node <NUM>. In some embodiments, the wireless device <NUM> also uses the associations between CQI index values and PTRS densities and/or patterns when selecting the CQI index to report, as described above. For example, the CQI index derivation procedure may take into account overhead in the CSI reference resource, where this overhead includes UE-specific reference signals and PTRS. The overhead due to the UE-specific reference signals (e.g., DMRS) can be determined by the wireless device <NUM> as described above. In addition, in some embodiments, the overhead due to PTRS in the CSI reference resource can be determined by the wireless device <NUM>, as described above.

Exemplary methods for CQI determination according to some embodiments disclosed herein are now discussed. At terminal side, the methods for CQI determination includes one or more of:.

For methods for CGI determination that include checking the PDSCH performance to determine whether a given performance is satisfied, it includes checking the BLER performance and/or spectrum efficiency performance and/or latency requirements. The performance metric is not limited to the above performance, and the other performance can also be used here. The BLER target may be given by high layer signaling or predefined for specific service or determined based on a predefined rule. If the BLER of PDSCH is smaller than the given threshold, it can be called BLER performance is satisfied. For spectrum efficiency performance, the requirements to be called spectrum efficiency are satisfied when BLER or latency requirements are satisfied and maximum spectrum efficiency is achieved.

As one embodiment, deriving the CQI based on the selected MCS which satisfies the given performance requirements includes selecting the CQI value which has the closest actual spectrum efficiency as the selected MCS. The actual spectrum efficiency will consider the byte alignment, number of available REs quantization, channel coding size adaptation, etc..

As another embodiment, deriving the CQI based on the selected MCS which satisfies the given performance requirements includes selecting the CQI value whose QIMCS · RIMCS is closest to the QCQIindex · RCQIindex which is indicated by the CQI index, QIMCS and RIMCS are obtained by the MCS index.

<FIG> is a flow chart that illustrates one example of the CQI index derivation procedure described above. As illustrated, the wireless device <NUM> selects an MCS index IMCSk (step <NUM>) and obtains a PTRS pattern and/or density according to the selected MCS index IMCSk (step <NUM>). In this embodiment, there is a known association between MCS index values and PTRS patterns and/or densities. These associations may be predefined (e.g., by standard), configured by the network (e.g., via RRC signaling), or determined by the wireless device <NUM> based on a predefined rule(s). The wireless device <NUM> determines a PDSCH performance given the selected MCS index IMCSk and the determined PTRS pattern and/or density (step <NUM>). As described above, in some embodiments, the PDSCH performance includes BLER and/or spectrum efficiency and/or latency. However, the PDSCH performance is not limited to these performance metrics. Any suitable performance metric may be used.

The wireless device <NUM> determines whether the determined PDSCH performance satisfies a predefined or preconfigured threshold PDSCH performance (step <NUM>). If not, the wireless device <NUM> selects a new MCS index IMCSk (step <NUM>) and the process returns to step <NUM>. Once the PDSCH performance, given the selected MCS index IMCSk and the determined PTRS pattern and/or density for the selected MCS index IMCSk, satisfies the performance threshold, the wireless device <NUM> selects that particular selected MCS index IMCSk as the MCS index for further CQI derivation (step <NUM>). The wireless device <NUM> then derives the CQI index to be reported to the network based on the selected MCS index IMCSk (step <NUM>). While not illustrated, in some embodiments, the wireless device <NUM> reports the derived CQI index to the network (e.g., to a radio access node <NUM> or low power node <NUM>).

Example embodiments of a radio access node and a wireless device according to some embodiments disclosed herein are now discussed. In this regard, <FIG> is a schematic block diagram of a radio access node <NUM> according to some embodiments of the present disclosure. The radio access node <NUM> may be, for example, a base station <NUM> or low power node <NUM>. As illustrated, the radio access node <NUM> includes a control system <NUM> that includes one or more processors <NUM> (e.g., Central Processing Units (CPUs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), and/or the like), memory <NUM>, and a network interface <NUM>. In addition, the radio access node <NUM> includes one or more radio units <NUM> that each includes one or more transmitters <NUM> and one or more receivers <NUM> coupled to one or more antennas <NUM>. In some embodiments, the radio unit(s) <NUM> is external to the control system <NUM> and connected to the control system <NUM> via, e.g., a wired connection (e.g., an optical cable). However, in some other embodiments, the radio unit(s) <NUM> and potentially the antenna(s) <NUM> are integrated together with the control system <NUM>. The one or more processors <NUM> operate to provide one or more functions of a radio access node <NUM> as described herein. In some embodiments, the function(s) are implemented in software that is stored, e.g., in the memory <NUM> and executed by the one or more processors <NUM>.

As used herein, a "virtualized" radio access node is an implementation of the radio access node <NUM> in which at least a portion of the functionality of the radio access node <NUM> is implemented as a virtual component(s) (e.g., via a virtual machine(s) executing on a physical processing node(s) in a network(s)). As illustrated, in this example, the radio access node <NUM> includes the control system <NUM> that includes the one or more processors <NUM> (e.g., CPUs, ASICs, FPGAs, and/or the like), the memory <NUM>, the network interface <NUM>, and the one or more radio units <NUM> that each includes the one or more transmitters <NUM> and the one or more receivers <NUM> coupled to the one or more antennas <NUM>, as described above. The control system <NUM> is connected to the radio unit(s) <NUM> via, for example, an optical cable or the like. The control system <NUM> is connected to one or more processing nodes <NUM> coupled to or included as part of a network(s) <NUM> via the network interface <NUM>. Each processing node <NUM> includes one or more processors <NUM> (e.g., CPUs, ASICs, FPGAs, and/or the like), a memory <NUM>, and a network interface <NUM>.

In this example, functions <NUM> of the radio access node <NUM> described herein are implemented at the one or more processing nodes <NUM> or distributed across the control system <NUM> and the one or more processing nodes <NUM> in any desired manner. In some particular embodiments, some or all of the functions <NUM> of the radio access node <NUM> described herein are implemented as virtual components executed by one or more virtual machines implemented in a virtual environment(s) hosted by the processing node(s) <NUM>. As will be appreciated by one of ordinary skill in the art, additional signaling or communication between the processing node(s) <NUM> and the control system <NUM> is used in order to carry out at least some of the desired functions <NUM>. Notably, in some embodiments, the control system <NUM> may not be included, in which case the radio unit(s) <NUM> communicates directly with the processing node(s) <NUM> via an appropriate network interface(s).

This discussion is equally applicable to the processing node <NUM> of <FIG> where the module(s) <NUM> may be implemented at one of the processing node(s) <NUM> or distributed across multiple processing node(s) <NUM> and/or distributed across the processing node(s) <NUM> and the control system <NUM>.

<FIG> is a schematic block diagram of a UE <NUM> according to some embodiments of the present disclosure. As illustrated, the UE <NUM> includes one or more processors <NUM> (e.g., CPUs, ASICs, FPGAs, and/or the like), a memory <NUM>, and one or more transceivers <NUM>, each including one or more transmitters <NUM> and one or more receivers <NUM> coupled to one or more antennas <NUM>. In some embodiments, the functionality of the UE <NUM> described above may be fully or partially implemented in software that is, e.g., stored in the memory <NUM> and executed by the processor(s) <NUM>.

With reference to <FIG>, in accordance with an embodiment, a communication system includes a telecommunication network <NUM>, such as a 3GPP-type cellular network, which comprises an access network <NUM>, such as a Radio Access Network (RAN), and a core network <NUM>. The access network <NUM> comprises a plurality of base stations 1406A, 1406B, 1406C, such as NBs, eNBs, gNBs, or other types of wireless Access Points (APs), each defining a corresponding coverage area 1408A, 1408B, 1408C. Each base station 1406A, 1406B, 1406C is connectable to the core network <NUM> over a wired or wireless connection <NUM>. A first UE <NUM> located in coverage area 1408C is configured to wirelessly connect to, or be paged by, the corresponding base station 1406C. A second UE <NUM> in coverage area 1408A is wirelessly connectable to the corresponding base station 1406A.

It is noted that the host computer <NUM>, the base station <NUM>, and the UE <NUM> illustrated in <FIG> may be similar or identical to the host computer <NUM>, one of the base stations 1406A, 1406B, 1406C, and one of the UEs <NUM>, <NUM> of <FIG>, respectively.

The wireless connection <NUM> between the UE <NUM> and the base station <NUM> is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to the UE <NUM> using the OTT connection <NUM>, in which the wireless connection <NUM> forms the last segment. More precisely, the teachings of these embodiments may improve, e.g., date rate, latency, and/or power consumption and thereby provide benefits such as, e.g., reduced user waiting time, relaxed restriction on file size, better responsiveness, and/or extended battery lifetime.

Claim 1:
A method performed by a wireless device for Channel Quality Indicator, CQI, index reporting in a wireless communication system, the method comprising:
deriving (<NUM>) a CQI index to be reported to a network node, where the CQI index is derived assuming a Physical Downlink Shared Channel, PDSCH, transmission on a Channel State Information, CSI, reference resource, wherein it is further assumed that a wireless device-specific reference signal overhead in the CSI reference resource is consistent with a number of additional Demodulation Reference Signal, DMRS, symbols; and
reporting (<NUM>) the CQI index to the network node.