TW201640849A - Method and apparatus for reporting csi for superposition transmission - Google Patents

Abstract

An objective of the present invention is to provide a method and apparatus for reporting CSI for superposition transmission. A first UE reports, based on a first BLER indicated by a corresponding base station, a first CSI corresponding to the first BLER to the base station; reports, based on at least one second BLER indicated by the base station, at least one second CSI corresponding to the at least one second BLER, to the base station, wherein the base station performs superposition transmission with the first UE and at least one second UE paired therewith, wherein a value of the at least one second BLER is different from a value of the first BLER. Compared with the prior art, the present invention does not require the UE to perform interference cancellation/ suppression during a CQI measurement period for the second CSI. Therefore, the present invention does not have the complication as found in the Post-NAICS CQI. The present invention designs some restrictions and/or changes some existing standards when generating a CSI report, such that the report is more useful and more beneficial to the superposition transmission schemes, which enhances system efficiency and promotes user experience.

Description

Method and apparatus for overlay transmission reporting channel status indicators

The present invention relates to the field of communication technologies, and more particularly to a technique for reporting a CSI (Channel Status Indicator) for overlay transmission.

In Rel-13, a research project to improve the performance of MU-MIMO (Multi User-Multiple-Input Multiple-Output) has been proposed recently, in which network-assisted interference cancellation and suppression are applied ( Network Assisted Interference Cancellation & Suppression, NAICS). This new feature is called Superposition Transmission, and its main target scenario is MU-MIMO with near-far UE. An example of having two UEs (user equipments) as shown in FIG. 1 , wherein the first UE is close to the base station, and the second UE is at the cell edge, and the base station (eg, eNodeB or eNB, evolved Node B) performs MU- MIMO pairs the first UE with the second UE. In this scenario, the signal to the second UE will have a higher power than the signal to the first UE, with the result that the first UE will be severely interfered. However, since the interference composed of the signal to the second UE at the first UE is too strong, the first UE may decode and eliminate/suppress the interference by decoding the information of the signal of the second UE. This information may be provided by the network (i.e., NAICS) and/or blindly decoded by the first UE.

It should be noted that FIG. 1 is an example of superimposed transmission in which two base stations are paired by a base station and power is allocated. It can be seen as another form of MU-MIMO where the base station will decide which UE to pair with and which precoding to use.

In existing systems, CQI (Channel Quality Indicator) Based on the PDSCH (Physical Downlink Shared Channel) transmission block size and MCS (Modulation and Coding Scheme), the UE can have a BLER (Block Error Ratio) of 10%. Rate) for decoding. The existing reported CQI does not consider interference cancellation/suppression, and if the "pessimistic" CQI is reported, the base station schedules a TBS (Transport Block Size) that is less than the required one. The advantages offered by NAICS are not fully utilized. Although outer loop link adaptation may ultimately cause the base station to schedule "appropriate" TBS, the process is slow and the interference conditions are required to remain unchanged during the adaptation process. During the Rel-12NAICS WI (work item) process, the CQI issue was extensively discussed as to whether the report needs improvement and several proposals were made. For example, one proposal is that the UE reports Post-NAICS CQI (post-NAICS CQI) and Pre-NAICS CQI (pre-NAICS CQI), where in Post-NAICS CQI, CQI is based on the cancelled interference, while Pre-NAICS CQI is The CQI (ie, the legacy CQI) of the interference is not eliminated. The UE provider argues that it is difficult to determine the Post-NAICS CQI, since the Post-NAICS CQI requires the UE to perform interference cancellation during CQI measurement, resulting in high UE complexity. In addition, it is not clear whether the CQI should be based on a CRS RE (Cell-specific Reference Signal Resource Element) or a PDSCH RE (Physical Downlink Shared Channel Resource Element). If it is based on PDSCH RE, it further complicates because the UE must rely on any scheduling information to decode the PDSCH from its serving base station. Due to this complexity, WI ultimately did not agree on the improvement of CQI. It is believed that the UE will report a "correct" CQI, and RAN4 (Radio Access Network 4) can design a test to ensure that the UE reports the "correct" CQI. However, since this test is still under study in RAN4, it is still unclear how to use this test.

RAN1 will study the overlay transmission scheme, which is attributed to the worst case in MU-MIMO. Condition or practice, and rely heavily on the interference cancellation capability of the UE. Therefore, similar problems are expected in the CQI report, and it is necessary to find a solution to solve the technical problem, which provides CQI feedback of the UE's interference cancellation capability, but avoids the complexity of generating Post-NAICS CQI.

Post-NAICS CQI is a known solution, but it produces a lot of complexity as described above. Moreover, the new SI (study item) for overlay transmission aims to dynamically multi-user transmission and pairing, which cannot be fully supported by the concept of post-NAICS CQI.

It is an object of the present invention to provide a method and apparatus for reporting CSI for overlay transmission.

According to an aspect of the present invention, a method for implementing CSI for overlay transmission reporting in a first UE is provided, wherein the method includes: a reporting to the base station according to a first BLER indicated by a corresponding base station a first CSI corresponding to the first BLER; b reporting, to the base station, at least one second CSI corresponding to the at least one second BLER according to the at least one second BLER indicated by the base station, where the base station And performing superposition transmission with the first UE and the at least one second UE paired thereto, wherein the value of the at least one second BLER is different from the value of the first BLER.

Preferably, the second CSI includes a second CQI, where the step b includes: - according to the at least one second BLER indicated by the base station, and combining the base station with the first UE and the at least one The second CQI is calculated by the power allocated by the UE.

Preferably, the method further includes: determining, according to the PMI/RI included in the first CSI, a PMI/RI included in the at least one second CSI; wherein the determining manner includes any one of the following :- the PMI/RI included in the at least one second CSI is the same as the PMI/RI included in the first CSI; - The PMI/RI included in the at least one second CSI is a sub-array of PMI/RI included in the first CSI.

Preferably, wherein the second CSI only includes the second CQI.

According to another aspect of the present invention, a method for facilitating reporting CSI for overlay transmission in a base station is also provided, wherein the method includes: - indicating a first BLER and at least one second BLER to a corresponding first UE, respectively, The value of the at least one second BLER is different from the value of the first BLER.

Preferably, the method further includes: - configuring a corresponding MCS for the first UE according to the first CSI and the at least one second CSI reported by the first UE.

Preferably, the method further includes: - according to the at least one second CSI reported by the first UE, and the CSI reported by the at least one second UE corresponding to the at least one second CSI, respectively At least one second UE configures the corresponding MCS.

According to another aspect of the present invention, a first UE that implements CSI for overlay transmission is also provided, where the first UE includes: a first reporting device, configured to use, according to a first BLER indicated by a corresponding base station, The base station reports a first CSI corresponding to the first BLER; the second reporting device is configured to report, to the base station, the at least one second BLER according to the at least one second BLER indicated by the base station At least one second CSI, wherein the base station performs superposition transmission with the first UE and at least one second UE paired thereto, wherein the value of the at least one second BLER is different from the first BLER value.

Preferably, the second CSI includes a second CQI, wherein the second reporting device is configured to: - combine the base station according to the at least one second BLER indicated by the base station The second CQI is calculated for the power allocated by the first UE and the at least one second UE.

Preferably, the first UE further includes: determining means, configured to determine, according to the PMI/RI included in the first CSI, a PMI/RI included in the at least one second CSI; wherein, determining The method includes any one of the following: - the PMI/RI included in the at least one second CSI is the same as the PMI/RI included in the first CSI; - the PMI/RI included in the at least one second CSI is A sub-array of PMI/RI included in the first CSI.

Preferably, wherein the second CSI only includes the second CQI.

According to still another aspect of the present invention, a base station is provided to assist in implementing CSI for overlay transmission, wherein the base station includes: indicating means for indicating a first BLER and at least one to a corresponding first UE, respectively. And a second BLER, wherein the value of the at least one second BLER is different from the value of the first BLER.

Preferably, the base station also includes: a first configuration device, configured to configure a corresponding MCS for the first UE according to the first CSI and the at least one second CSI reported by the first UE.

Preferably, the base station further includes: a second configuration device, configured to: according to the at least one second CSI reported by the first UE, and the at least one second UE corresponding to the at least one second CSI The reported CSI configures the corresponding MCS for the at least one second UE, respectively.

According to still another aspect of the present invention, there is also provided a system for implementing CSI for overlay transmission reporting, comprising a first UE as described above and a base station as described above.

Compared with the prior art, the present invention provides base station information that the victim UE can eliminate the interference level under MU-MIMO operation. Victim UE provides an existing system based a first CSI, and at least one second CSI corresponding to the at least one paired UE, the second CSI being related to an interference cancellation capability of the victim UE, and utilizing a second CSI different from the first CSI BLER.

Unlike the Post-NAICS CQI proposed in Rel-12 NAICS, the present invention does not require the UE to perform interference cancellation/suppression during CQI measurement for the second CSI. Therefore, the present invention does not have the complexity as found in the Post-NAICS CQI. The present invention designs constraints and/or changes some existing standards in generating CSI reports to make them more useful, and more efficient for overlay transmission schemes, improving system efficiency and improving user experience.

In addition, in the present invention, the base station configures the corresponding MCS for the victim UE according to the first CSI and the second CSI reported by the victim UE; the base station also reports the second CSI and the interferer according to the victim UE. The CSI reported by the UE configures the corresponding MCS for the interferer UE, further improving system efficiency and improving the user experience.

301‧‧‧First reporting device

302‧‧‧Second reporting device

S201‧‧‧ steps

S202‧‧‧Steps

Other features, objects, and advantages of the present invention will become more apparent from the detailed description of the accompanying drawings. A flowchart showing a method for implementing CSI for overlay transmission reporting in a first UE according to an aspect of the present invention; FIG. 3 is a diagram showing an apparatus for implementing CSI for overlay transmission reporting in a first UE according to another aspect of the present invention; schematic diagram.

The same or similar reference numerals in the drawings denote the same or similar components.

While the invention may be susceptible to various modifications and alternative forms, It should be understood, however, that the invention is not intended to be limited Modifications, equivalents and alternatives. The same reference numbers are used throughout the description of the drawings.

Before discussing the exemplary embodiments in more detail, it should be noted that some exemplary embodiments are described as a process or method depicted as a flowchart. Although the flowcharts describe various operations as a sequential process, many of the operations can be implemented in parallel, concurrently or concurrently. In addition, the order of operations can be rearranged. The process can be terminated when its operation is completed, but can also have additional steps not included in the figures. This processing may correspond to methods, functions, routines, subroutines, subroutines, and the like.

The term "wireless device" or "device" as used herein may be considered synonymous with the following and may sometimes be referred to as the following: client, user device, mobile station, mobile user, Mobile terminals, users, users, remote stations, access terminals, receivers, mobile units, etc., and can describe remote users of wireless resources in a wireless communication network.

Similarly, the term "base station" as used herein may be considered synonymous with the following and may sometimes be referred to as the following: Node B, evolved Node B, eNodeB, transceiver base station ( BTS), RNC, etc., and may describe a transceiver that communicates with and provides wireless resources to a mobile terminal that can span multiple technical generations. In addition to the ability to implement the methods discussed herein, the base stations discussed herein can have all of the functionality associated with conventional well-known base stations.

The methods discussed below, some of which are illustrated by flowcharts, can be implemented by hardware, software, firmware, intermediate software, microcode, hardware description language, or any combination thereof. When implemented in software, firmware, intermediate software or microcode, the code or code segments used to carry out the necessary tasks can be stored in a machine or computer readable medium (such as a storage medium). The processor(s) can perform the necessary tasks.

The specific structural and functional details disclosed herein are merely representative and are for the purpose of describing exemplary embodiments of the invention. However, the invention can be replaced by many The implementation is specific and should not be construed as being limited to the embodiments set forth herein.

It will be understood that, although the terms "first", "second", and the like may be used herein to describe the various elements, such elements are not limited by the terms. The use of such terms is merely intended to distinguish one unit from another. For example, a first unit could be termed a second unit, and similarly a second unit could be termed a first unit, without departing from the scope of the exemplary embodiments. The term "and/or" used herein includes any and all combinations of one or more of the associated listed items.

It will be understood that when a unit is referred to as "connected" or "coupled" to another unit, it can be directly connected or coupled to the other unit, or an intermediate unit can be present. In contrast, when a unit is referred to as "directly connected" or "directly coupled" to another unit, there is no intermediate unit. Other words used to describe the relationship between the units should be interpreted in a similar manner (eg "between" and "directly between" and "close to" Than "directly adjacent to", etc.).

The terminology used herein is for the purpose of describing the particular embodiments, The singular forms "a", "an", and <RTIgt; It is also to be understood that the terms "comprising" and / or "comprising" are used to mean the presence of the recited features, integers, steps, operations, units and/or components, and do not exclude the presence or addition of one or more additional features. , integers, steps, operations, units, components, and/or combinations thereof.

It should also be noted that in some alternative implementations, the functions/acts noted may occur in a different order than those illustrated in the drawings. For example, two figures shown in succession may be executed substantially concurrently or in the reverse order, depending on the function/acts involved.

All terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art, unless otherwise defined. also It should be understood that the terms defined in the commonly used dictionary, for example, should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and should not be idealized, unless explicitly defined herein. Or an overly formal meaning to explain.

The basic idea of the invention is to provide at least two CSI reports for the UE. The CSI report includes a parameter CQI (Channel Quality Indicator), a PMI (Precoding Matrix Indicator), or an RI (Ranking Indication). Among them, in each CSI, the parameters (CQI/PMI/RI) are based on different constraints. The UE providing the different CSI report is, for example, a UE close to the base station, such as the first UE performing interference cancellation in FIG. Other UEs, such as the second UE, will still measure the channel as usual. However, the base station scheduler should consider the feedback reported from the first UE and the second UE in a comprehensive manner and perform reasonable scheduling adjustments.

Preferably, when the first UE has multiple second UEs paired with the same, if the multiple second UEs also need to perform interference cancellation, they may also report multiple CSIs with different BLERs.

For the sake of brevity, the following describes the first UE that needs to perform interference cancellation as an example.

It should be noted that in the 3GPP standard, since it allows the UE provider to implement its own receiver, the derivation of CQI is based on the implementation of the UE. In addition to being a receiver of the UE, CQI is also a function of the radio propagation channel. Since the base station is not aware of the implementation of individual users and the wireless channel propagation can vary, it is difficult (or impossible) for the base station to derive or determine a specific BLER based on a BLER (eg, 10%) CQI (eg, 1%). The CQI of the UE. It should also be noted that the usual interpolation based on a single point (e.g., CQI of 10% BLER) is not achievable.

2 shows a flow chart of a method for implementing CSI reporting for overlay transmission in a first UE in accordance with an aspect of the present invention.

In step S201, the first UE is first according to the corresponding base station indication. The BLER reports the first CSI corresponding to the first BLER to the base station.

Specifically, the base station, here, for example, the eNB, indicates the first BLER to the first UE by means of pre-configuration or transmission to the first UE; the first UE according to the first BLER indicated by the base station, Channel measurement is performed, and parameter information such as CQI, PMI or RI is obtained, a first CSI is generated, and the first CSI is reported to the base station by the first BLER.

In step S202, the first UE reports, to the base station, at least one second CSI corresponding to the at least one second BLER according to the at least one second BLER indicated by the base station, where the base station and the first Superimposed transmission between a UE and at least one second UE paired therewith, wherein the value of the at least one second BLER is different from the value of the first BLER.

Specifically, the base station indicates at least one second BLER to the first UE, in addition to indicating a first BLER to the first UE, where the value of the at least one second BLER is different from the value of the first BLER. Preferably, the value of the at least one second BLER is lower than the value of the first BLER.

The first UE performs channel measurement according to the at least one second BLER indicated by the base station, and obtains parameter information such as CQI, PMI, or RI, respectively generates at least one second CSI, and reports the at least one second BLER respectively. To the base station.

Here, the superimposed transmission is performed between the base station and the at least one second UE that is paired with the first UE, that is, the base station sends the multiple to the first UE and the at least one second UE. Information is superimposed for transmission. Therefore, the at least one second UE generates different degrees of interference to the first UE.

Here, depending on the design, such as BLER and/or PMI and/or RI constraints, higher layer messaging is required to indicate new constraints on the UE (such as the first UE here) to enable the first UE to comply with the new report. standard.

The second CSI effectively represents the likelihood that the interference is cancelled, or the likelihood that the first UE can obtain the first CSI.

Preferably, the value of the at least one second BLER is lower than the value of the first BLER, and the value may be defined in a specification or notified by a network.

In an embodiment, the first UE has a plurality of second UEs paired with the first UE, for example, the first UE has three second UEs paired thereto, and is referred to herein as a second UE, respectively. Three UEs and a fourth UE. The base station performs the superimposed transmission with the first UE, the second UE, the third UE, and the fourth UE. Therefore, the second UE, the third UE, and the fourth UE respectively generate the first UE to different degrees. interference.

Preferably, the number of the second CSIs corresponds to the number of the second UEs.

In this embodiment, since the first UE has three second UEs paired with it, the first UE needs to report three corresponding second CSIs.

More preferably, the first UE sorts the at least one interference according to the power level of the at least one interference generated by the at least one second UE; according to the ranking, from the at least one second BLER indicated by the base station The corresponding BLER is determined in turn, and the corresponding CSI is calculated.

In this embodiment, it is assumed that the first UE is closest to the base station, and the second UE, the third UE, and the fourth UE are respectively away from the base station in sequence. Therefore, in the superimposed transmission scheme of the MU-MIMO, the power allocated by the base station to the fourth UE is the highest, the power allocated to the third UE is second, and the power allocated to the second UE is again A UE allocates the lowest power. Therefore, the fourth UE, the third UE, and the second UE respectively generate different degrees of interference to the first UE. The first UE sorts the interference according to the power level of the interferences, and determines the value of the corresponding BLER. For example, if the power level of the interference generated by the second UE is the lowest, the value of the corresponding BLER is higher, the value of the BLER corresponding to the third UE is lower than that of the second UE, and the BLER corresponding to the fourth UE is The value is the lowest. Then, the first UE calculates a corresponding CSI according to the BLERs, and reports to the base station.

In another embodiment, the first UE has a second UE paired with it. The base station indicates the first BLER and the second BLER to the first UE, where the second BLER The value is different from the value of the first BLER. For example, the value of the first BLER is 10% and the value of the second BLER is 1%. The first UE first reports the first CSI corresponding to the first BLER to the base station according to the first BLER; then, the first UE reports, according to the second BLER, the base station to the second BLER according to the second BLER. The second CSI.

Taking the scenario in FIG. 1 as an example, it is used for pairing of near-far UEs, that is, for MU-MIMO transmission, the first UE and the second UE are paired. The base station configures the first UE to report 2 CSIs, wherein the first CSI is based on an existing system, based on a BLER such as 10%; the second CSI is based on different constraints, such as a 1% BLER.

For MU-MIMO, when the base station ensures that the first UE is paired with another UE (such as the second UE), the other UE (second UE) can be scheduled to make the MCS of the other UE (second UE) and The TBS does not exceed the MCS and TBS corresponding to the reported second CSI. It allows the victim UE (first UE) to reliably cancel interference from the other UE (second UE).

Since the generation of CSI based on the existing system does not consider the interference of MU-MIMO, if the interference of MU-MIMO is completely canceled or suppressed, the first CSI will effectively serve as the CSI that the UE will experience. The existing CQI/PMI/RI definition and feedback mechanism has not changed for the first CSI.

The second CSI represents interference that the UE can decode. The second CSI is related to the interference cancellation capability of the UE. The idea here is to reuse existing CQI/PMI/RI definition and feedback mechanisms as much as possible, but requires some additional constraints or changes so that the second CSI can provide a reference for interference cancellation for overlay transmissions of a particular UE.

Different BLERs are utilized in the second CSI because the UE is capable of canceling the receiver decoding interference based on interference at the symbol level or codeword level without any HARQ retransmission and without going through the complete decoding chain. In other words, the UE needs to be able to decode the interference with high reliability, which results in the interferer UE (second UE) having a lower MCS than the MCS of the signal. In the near-far MU-MIMO scenario, since the interferer UE (second UE) is at the cell edge, It is desirable for the interferer UE to have an MCS that is lower than the victim UE (eg, the first UE that is closer to the base station) based on the overlay transmission scheme.

Unlike the Post-NAICS CQI proposed in Rel-12 NAICS, the present invention does not require the UE to perform interference cancellation/suppression during CQI measurement for the second CSI. Therefore, the present invention does not have the complexity as found in the Post-NAICS CQI. In addition, the UE only needs to perform the same measurement (such as CRS) to generate two CSI reports.

Also, the two CSI reports here are not based on multiple CSI processes originally designed for CoMP. The present invention designs some constraints when generating CSI reports and/or changes some existing standards to make them more useful and more efficient for overlay transmission schemes.

For the sake of brevity, the following examples are described in the case where the first UE and a second UE are paired.

Preferably, the second CSI includes a second CQI, wherein, in step S202, the first UE is in accordance with the at least one second BLER indicated by the base station, and the base station is combined with the first UE and the at least Calculating the second CQI by the power allocated by the second UE.

Specifically, since the CSI includes the parameter CQI, PMI, or RI, for the CQI therein, it can be calculated by receiving the RSRP (Reference Signal Received Power) from the base station and the BLER indicated by the base station. The base station is configured to perform the superimposed transmission between the base station and the first UE and the second UE that is paired with the base station. Therefore, when calculating the CQI, the first UE may also consider that the base station is the first UE and the second UE. The power allocated.

In the superimposed transmission, the base station allocates different powers for different transmissions, taking the case of the first UE and the second UE pairing as an example, and assumes that the location of the first UE and the second UE from the base station is as shown in FIG. Then, the base station can allocate 70% of the total power to the second UE, and allocate only 30% of the total power to the first UE. When calculating the CQI, the first UE considers the power allocation of the base station in combination.

Here, the power allocated for the first UE and the second UE is determined by the base station, and the calculation of the CQI can ensure a certain power allocation.

Preferably, a power split (as between the first UE and the second UE) is notified to the first UE and the second UE as part of the configuration or specified in the specification.

Preferably, the first UE determines a PMI/RI included in the at least one second CSI according to the PMI/RI included in the first CSI; wherein the manner of determining includes any one of the following: - the at least The PMI/RI included in one second CSI is the same as the PMI/RI included in the first CSI; - the PMI/RI included in the at least one second CSI is the PMI/ included in the first CSI Subarray of RI.

Here, the PMI/RI included in the second CSI depends on the PMI/RI included in the first CSI. In the second determination manner, that is, when the PMI/RI included in the at least one second CSI is a sub-array of the PMI/RI included in the first CSI, the RI will correspond to the size of the sub-array, such as , rank 1, and additional indications are needed to determine which layer or layers correspond to the PMIs contained in the first CSI.

Preferably, wherein the second CSI only includes the second CQI.

Here, depending on the constraint design for the PMI/RI included in the second CSI, the second CSI may only include the second CQI, ie, the first UE reports only the CQI without reporting the PMI/RI. For example, when the PMI/RI included in the second CSI is the same as the PMI/RI included in the first CSI, the first UE reports only the CQI, and does not report the PMI/RI.

Preferably, the first CSI and the at least one second CSI are reported to the base station together with a new PUCCH (Physical Uplink Control Channel) format.

Preferably, the second CSI includes the second CQI and the first CSI The difference between the first CQI.

Here, the second CQI may use the first CQI as a reference, calculate a difference between the second CQI and the first CQI, and report the difference by a short-term or long-term interval.

Preferably, the first CSI and the at least one second CSI are reported to the base station in a Time Division Multiplexing (TDM) manner.

Here, this reporting mode allows the use of existing PUCCH formats, but different CSIs are reported at different times.

Preferably, the first CSI and the at least one second CSI are reported to the base station in different periods.

Here, the first CSI has a different period from the second CSI, for example, the first CSI is reported to the base station more frequently than the second CSI.

Preferably, when there are multiple second CSIs, the multiple second CSIs may also follow the above rules. For example, the multiple second CSIs are reported to the base station together in a new PUCCH format. The multiplex mode is reported to the base station and reported to the base station in different cycles.

According to another aspect of the present invention, there is also provided a method of assisting in implementing CSI reporting for overlay transmission in a base station.

The base station indicates the first BLER and the at least one second BLER to the corresponding first UE, where the value of the at least one second BLER is different from the value of the first BLER.

Here, in addition to indicating the first BLER of the existing system to the first UE, the base station also needs to indicate a different second BLER for the interfering UE. The first BLER and the second BLER may be separately sent to the first UE, or may be sent to the first UE together in the configuration in advance.

Preferably, the value of the at least one second BLER is lower than the value of the first BLER.

Preferably, the base station according to the first CSI reported by the first UE and at least A second CSI configures a corresponding MCS for the first UE.

Different from the inter-cell NAICS (as in Rel-12), in the present invention, the interference to be eliminated in MU-MIMO is generated by the serving base station, that is, the serving base station controls to the victim UE (such as the first UE). ) Signal and interference. The base station can therefore schedule UE pairing for MU-MIMO.

Taking the first UE and a second UE paired with it as an example, the base station (such as the scheduler in the base station) configures the first UE according to the first CSI and the second CSI reported by the first UE. MCS. For example, the corresponding MCS is configured for the first UE according to the formula CQI #1-α* CQI #2. Here, CQI #1 indicates the first CQI included in the first CSI, CQI #2 indicates the second CQI included in the second CSI, and α is a coefficient, and the value may be based on OLLA (Outer Loop Link Adaptation, outer layer) Cyclic link adaptation) and UE capabilities are slowly adjusted. Here, the MCS configured by the base station for the first UE does not exceed the MCS corresponding to the first CSI.

Preferably, the base station reports, according to the at least one second CSI reported by the first UE, and the CSI reported by the at least one second UE corresponding to the at least one second CSI, respectively, the at least one The two UEs correspond to the MCS.

Taking the first UE and a second UE paired thereto as an example, the base station configures the corresponding MCS for the second UE according to the second CSI reported by the first UE and the CSI reported by the second UE. . Here, the MCS configured by the base station for the second UE does not exceed the MCS corresponding to the second CSI reported by the first UE.

Here, the base station considers the CSI feedback directly from the second UE according to the second CSI reported by the first UE, for example, increasing the scheduling priority of the second UE located at the cell edge.

More preferably, if the base station configures the MCS for the second UE to be higher than the MCS corresponding to the second CSI reported by the first UE, the base station configures a lower MCS for the first UE. . Because the first UE cannot cancel the second UE generated with the desired reliability. interference. Of course, the MCS configured for the first UE and the second UE depends on the base station, such as the scheduler within the base station.

3 shows a schematic diagram of an apparatus for implementing CSI reporting for overlay transmission in a first UE in accordance with another aspect of the present invention. The first UE includes a first reporting device 301 and a second reporting device 302.

The first reporting device 301 in the first UE reports the first CSI corresponding to the first BLER to the base station according to the first BLER indicated by the corresponding base station.

Specifically, the base station, here, for example, an eNB, indicates the first BLER to the first UE by means of pre-configuration or transmission to the first UE; the first reporting device 301 of the first UE is according to the base station Instructing the first BLER, performing channel measurement, and obtaining parameter information such as CQI, PMI, or RI, generating a first CSI, and reporting the first CSI to the base station by using the first BLER.

The second reporting device 302 in the first UE reports at least one second CSI corresponding to the at least one second BLER to the base station according to the at least one second BLER indicated by the base station, where the base station and the base station The superimposed transmission is performed between the first UE and the at least one second UE paired therewith, wherein the value of the at least one second BLER is different from the value of the first BLER.

Specifically, the base station indicates at least one second BLER to the first UE, in addition to indicating a first BLER to the first UE, where the value of the at least one second BLER is different from the value of the first BLER. Preferably, the value of the at least one second BLER is lower than the value of the first BLER.

The second reporting device 302 in the first UE performs channel measurement according to the at least one second BLER indicated by the base station, and obtains parameter information such as CQI, PMI or RI, respectively generates at least one second CSI, and respectively generates The at least one second BLER is reported to the base station.

Here, the base station and the first UE and at least one second UE paired therewith The superimposed transmission is performed, that is, the plurality of information sent by the base station to the first UE and the at least one second UE are superimposed and transmitted. Therefore, the at least one second UE generates different degrees of interference to the first UE.

Here, depending on the design, such as BLER and/or PMI and/or RI constraints, higher layer messaging is required to indicate new constraints on the UE (such as the first UE here) to enable the first UE to comply with the new report. standard.

The second CSI effectively represents the likelihood that the interference is cancelled, or the likelihood that the first UE can obtain the first CSI.

Preferably, the value of the at least one second BLER is lower than the value of the first BLER, and the value may be defined in a specification or notified by a network.

In an embodiment, the first UE has a plurality of second UEs paired with the first UE, for example, the first UE has three second UEs paired thereto, and is referred to herein as a second UE, respectively. Three UEs and a fourth UE. Performing superimposed transmission between the base station and the first UE, the second UE, the third UE, and the fourth UE, and therefore, the second UE, the third UE, and the fourth UE respectively use the first UE to different degrees Interference.

Preferably, the number of the second CSIs corresponds to the number of the second UEs.

In this embodiment, since the first UE has three second UEs paired with it, the first UE needs to report three corresponding second CSIs.

More preferably, the first UE sorts the at least one interference according to the power level of the at least one interference generated by the at least one second UE; according to the ranking, from the at least one second BLER indicated by the base station The corresponding BLER is determined in turn, and the corresponding CSI is calculated.

In this embodiment, it is assumed that the first UE is closest to the base station, and the second UE, the third UE, and the fourth UE are respectively away from the base station in sequence. Therefore, in the superimposed transmission scheme of the MU-MIMO, the power allocated by the base station to the fourth UE is the highest, the power allocated to the third UE is second, and the power allocated to the second UE is again One UE allocates the most power low. Therefore, the fourth UE, the third UE, and the second UE respectively generate different degrees of interference to the first UE. The first UE sorts the interference according to the power level of the interferences, and determines the value of the corresponding BLER. For example, if the power level of the interference generated by the second UE is the lowest, the value of the corresponding BLER is higher, the value of the BLER corresponding to the third UE is lower than that of the second UE, and the BLER corresponding to the fourth UE is The value is the lowest. Then, the first UE calculates a corresponding CSI according to the BLERs, and reports to the base station.

In another embodiment, the first UE has a second UE paired with it. The base station indicates the first BLER and the second BLER to the first UE, where the value of the second BLER is different from the value of the first BLER. For example, the value of the first BLER is 10% and the value of the second BLER is 1%. The first UE first reports the first CSI corresponding to the first BLER to the base station according to the first BLER; then, the first UE reports, according to the second BLER, the base station to the second BLER according to the second BLER. The second CSI.

Taking the scenario in FIG. 1 as an example, it is used for pairing of near-far UEs, that is, for MU-MIMO transmission, the first UE and the second UE are paired. The base station configures the first UE to report 2 CSIs, wherein the first CSI is based on an existing system, based on a BLER such as 10%; the second CSI is based on different constraints, such as a 1% BLER.

For MU-MIMO, when the base station ensures that the first UE is paired with another UE (such as the second UE), the other UE (second UE) can be scheduled to make the MCS of the other UE (second UE) and The TBS does not exceed the MCS and TBS corresponding to the reported second CSI. It allows the victim UE (first UE) to reliably cancel interference from the other UE (second UE).

Since the generation of CSI based on the existing system does not consider the interference of MU-MIMO, if the interference of MU-MIMO is completely canceled or suppressed, the first CSI will effectively serve as the CSI that the UE will experience. The existing CQI/PMI/RI definition and feedback mechanism has not changed for the first CSI.

The second CSI represents interference that the UE can decode. Interference cancellation of the second CSI and UE Ability related. The idea here is to reuse existing CQI/PMI/RI definition and feedback mechanisms as much as possible, but requires some additional constraints or changes so that the second CSI can provide a reference for interference cancellation for overlay transmissions of a particular UE.

Different BLERs are utilized in the second CSI because the UE is capable of canceling the receiver decoding interference based on interference at the symbol level or codeword level without any HARQ retransmission and without going through the complete decoding chain. In other words, the UE needs to be able to decode the interference with high reliability, which results in the interferer UE (second UE) having a lower MCS than the MCS of the signal. In the near-far MU-MIMO scenario, since the interferer UE (second UE) is at the cell edge, it is expected that the interferer UE has lower than the victim UE based on the superimposed transmission scheme (eg, closer to the base station) One UE) MCS.

Unlike the Post-NAICS CQI proposed in Rel-12 NAICS, the present invention does not require the UE to perform interference cancellation/suppression during CQI measurement for the second CSI. Therefore, the present invention does not have the complexity as found in the Post-NAICS CQI. In addition, the UE only needs to perform the same measurement (such as CRS) to generate two CSI reports.

Also, the two CSI reports here are not based on multiple CSI processes originally designed for CoMP. The present invention designs some constraints when generating CSI reports and/or changes some existing standards to make them more useful and more efficient for overlay transmission schemes.

For the sake of brevity, the following examples are described in the case where the first UE and a second UE are paired.

Preferably, the second CSI includes a second CQI, wherein the second reporting device 302 in the first UE is combined with the base station as the first UE according to the at least one second BLER indicated by the base station. The power allocated by the at least one second UE calculates the second CQI.

Specifically, since the CSI includes the parameter CQI, PMI, or RI, for the CQI therein, it can be calculated by receiving the RSRP (Reference Signal Received Power) from the base station and the BLER indicated by the base station. Because of this The base station performs the superimposed transmission between the first UE and the second UE that is paired with the second UE. Therefore, when the second reporting device 302 in the first UE calculates the CQI, the base station may also consider the first UE and the first UE. The power allocated by the two UEs.

In the superimposed transmission, the base station allocates different powers for different transmissions, taking the case of the first UE and the second UE pairing as an example, and assumes that the location of the first UE and the second UE from the base station is as shown in FIG. Then, the base station can allocate 70% of the total power to the second UE, and allocate only 30% of the total power to the first UE. The second reporting device 302 in the first UE considers the power allocation of the base station in combination when calculating the CQI.

Here, the power allocated for the first UE and the second UE is determined by the base station, and the calculation of the CQI can ensure a certain power allocation.

Preferably, a power split (as between the first UE and the second UE) is notified to the first UE and the second UE as part of the configuration or specified in the specification.

Preferably, the first UE also includes a determining device (not shown). The determining means determines the PMI/RI included in the at least one second CSI according to the PMI/RI included in the first CSI; wherein the determining manner includes any one of the following: - the at least one second CSI The PMI/RI included is the same as the PMI/RI included in the first CSI; - the PMI/RI included in the at least one second CSI is a sub-array of PMI/RI included in the first CSI.

Here, the PMI/RI included in the second CSI depends on the PMI/RI included in the first CSI. In the second determination manner, that is, when the PMI/RI included in the at least one second CSI is a sub-array of PMI/RI included in the first CSI, the RI will correspond to the size of the sub-array. For example, rank 1, and additional indications are needed to determine which layer or layers correspond to the PMIs contained in the first CSI.

Preferably, wherein the second CSI only includes the second CQI.

Here, depending on the constraint design for the PMI/RI included in the second CSI, the second CSI may only include the second CQI, ie, the first UE reports only the CQI without reporting the PMI/RI. For example, when the PMI/RI included in the second CSI is the same as the PMI/RI included in the first CSI, the first UE reports only the CQI, and does not report the PMI/RI.

Preferably, the first CSI and the at least one second CSI are reported to the base station together with a new PUCCH (Physical Uplink Control Channel) format.

Preferably, the second CSI includes a difference between the second CQI and a first CQI included in the first CSI.

Here, the second CQI may use the first CQI as a reference, calculate a difference between the second CQI and the first CQI, and report the difference by a short-term or long-term interval.

Preferably, the first CSI and the at least one second CSI are reported to the base station in a Time Division Multiplexing (TDM) manner.

Here, this reporting mode allows the use of existing PUCCH formats, but different CSIs are reported at different times.

Preferably, the first CSI and the at least one second CSI are reported to the base station in different periods.

Here, the first CSI has a different period from the second CSI, for example, the first CSI is reported to the base station more frequently than the second CSI.

Preferably, when there are multiple second CSIs, the multiple second CSIs may also follow the above rules. For example, the multiple second CSIs are reported to the base station together in a new PUCCH format. The multiplex mode is reported to the base station and reported to the base station in different cycles.

According to yet another aspect of the present invention, there is also provided a base station that facilitates reporting CSI for overlay transmission. The base station includes a pointing device (not shown), or preferably also includes A configuration device (not shown) and a second configuration device (not shown).

The indicating device of the base station respectively indicates the first BLER and the at least one second BLER to the corresponding first UE, where the value of the at least one second BLER is different from the value of the first BLER.

Here, the pointing device of the base station needs to indicate the second BLER different for the interfering UE in addition to indicating the first BLER of the existing system to the first UE. The first BLER and the second BLER may be separately sent to the first UE, or may be sent to the first UE together in the configuration in advance.

Preferably, the value of the at least one second BLER is lower than the value of the first BLER.

Preferably, the first configuration device of the base station configures a corresponding MCS for the first UE according to the first CSI and the at least one second CSI reported by the first UE.

Different from the inter-cell NAICS (as in Rel-12), in the present invention, the interference to be eliminated in MU-MIMO is generated by the serving base station, that is, the serving base station controls to the victim UE (such as the first UE). ) Signal and interference. The base station can therefore schedule UE pairing for MU-MIMO.

Taking the first UE and a second UE paired with it as an example, the first configuration device of the base station (such as the scheduler in the base station) is configured according to the first CSI and the second CSI reported by the first UE. The first UE configures the corresponding MCS. For example, the corresponding MCS is configured for the first UE according to the formula CQI #1-α*CQI #2. Here, CQI #1 indicates the first CQI included in the first CSI, CQI #2 indicates the second CQI included in the second CSI, and α is a coefficient, and the value may be based on OLLA (Outer Loop Link Adaptation, outer layer) Cyclic link adaptation) and UE capabilities are slowly adjusted. Here, the MCS configured by the base station for the first UE does not exceed the MCS corresponding to the first CSI.

Preferably, the second configuration device of the base station reports the CSI reported by the at least one second CSI reported by the first UE, and the at least one second UE corresponding to the at least one second CSI. The corresponding MCS is configured for the at least one second UE, respectively.

Taking the first UE and a second UE paired with it as an example, the second configuration device of the base station is the second CSI according to the second CSI reported by the first UE and the CSI reported by the second UE. The UE configures the corresponding MCS. Here, the MCS configured by the base station for the second UE does not exceed the MCS corresponding to the second CSI reported by the first UE.

Here, the base station considers the CSI feedback directly from the second UE according to the second CSI reported by the first UE, for example, increasing the scheduling priority of the second UE located at the cell edge.

More preferably, if the base station configures the MCS for the second UE to be higher than the MCS corresponding to the second CSI reported by the first UE, the base station configures a lower MCS for the first UE. . Because the first UE cannot cancel the interference generated by the second UE with the desired reliability. Of course, the MCS configured for the first UE and the second UE depends on the base station, such as the scheduler within the base station.

It is noted that the present invention can be implemented in a combination of software and/or software and hardware. For example, the various devices of the present invention can be implemented using a special application integrated circuit (ASIC) or any other similar hardware device. In one embodiment, the software program of the present invention may be executed by a processor to implement the above steps or functions. Similarly, the software program of the present invention (including related material structures) can be stored in a computer readable recording medium such as a RAM memory, a disk drive or a CD player or a floppy disk and the like. In addition, some of the steps or functions of the present invention may be implemented in hardware, for example, as a circuit that cooperates with a processor to perform various steps or functions.

It is obvious to those skilled in the art that the present invention is not limited to the details of the above-described exemplary embodiments, and the present invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the present embodiments are to be considered as illustrative and not restrictive, and the scope of the invention is defined by the scope of the appended claims rather All changes in the meaning and scope of the equivalents of the patent scope are included in the invention. Should not be included in the scope of patent application Any reference number is considered to limit the scope of the patent application involved. In addition, it is obvious that the word "comprising" does not exclude other elements or steps, and the singular does not exclude the plural. A plurality of units or devices recited in the scope of the system application can also be implemented by a unit or device by software or hardware. The first, second, etc. words are used to denote names and do not denote any particular order.

While the invention has been particularly shown and described, it is understood that the invention may be modified in its form and detail form, without departing from the spirit and scope of the invention. The protection sought here is set forth in the scope of the accompanying patent application. These and other aspects of the various embodiments are set forth in the following numbered clauses:

A method for implementing CSI for overlay transmission in a first UE, wherein the method comprises: a reporting, to the base station, a first corresponding to the first BLER according to a first BLER indicated by a corresponding base station The CSI;b reports, to the base station, at least one second CSI corresponding to the at least one second BLER according to the at least one second BLER indicated by the base station, where the base station and the first UE The superimposed transmission is performed between the paired at least one second UE, wherein the value of the at least one second BLER is different from the value of the first BLER.

2. The method of clause 1, wherein the second CSI comprises a second CQI, wherein the step b comprises: - according to the at least one second BLER indicated by the base station, and combining the base station with the first UE And calculating the second CQI by the power allocated by the at least one second UE.

3. The method of claim 1, wherein the method further comprises: - determining a PMI/RI included in the at least one second CSI according to a PMI/RI included in the first CSI; wherein the manner of determining Any one of the following: - the PMI/RI included in the at least one second CSI and the one included in the first CSI The PMI/RI is the same; the PMI/RI included in the at least one second CSI is a sub-array of PMI/RI included in the first CSI.

4. The method of clause 1, wherein the second CSI only includes the second CQI.

5. The method of clause 1, wherein the number of the second CSIs corresponds to the number of the second UEs.

6. The method of clause 1, wherein the method further comprises: - sorting the at least one interference according to a power level of the at least one interference generated by the at least one second UE; - according to the ranking, The corresponding BLER is sequentially determined in at least one second BLER indicated by the base station, and the corresponding CSI is calculated.

7. The method of clause 1, wherein the value of the at least one second BLER is lower than the value of the first BLER.

8. The method of clause 1, wherein the first CSI and the at least one second CSI are reported to the base station in a new PUCCH format.

9. The method of clause 1, wherein the second CSI comprises a difference between the second CQI and a first CQI included in the first CSI.

10. The method of clause 1, wherein the first CSI and the at least one second CSI are reported to the base station in a time division multiplex manner.

11. The method of clause 1, wherein the first CSI and the at least one second CSI are reported to the base station in different periods.

12. A method for assisting in implementing CSI for overlay transmission in a base station, wherein the method comprises: - indicating a first BLER and at least one second BLER to a corresponding first UE, wherein the at least one second BLER The value is different from the value of the first BLER.

13. The method of clause 12, wherein the method further comprises: - configuring a corresponding MCS for the first UE according to the first CSI and the at least one second CSI reported by the first UE.

The method of claim 13, wherein the method further comprises: - reporting, according to the at least one second CSI reported by the first UE, and at least one second UE corresponding to the at least one second CSI The CSI configures a corresponding MCS for the at least one second UE.

A first UE that implements reporting CSI for overlay transmission, wherein the first UE includes: a first reporting device, configured to report the first BLER to the base station according to a first BLER indicated by the corresponding base station Corresponding first CSI; the second reporting device is configured to report, to the base station, at least one second CSI corresponding to the at least one second BLER according to the at least one second BLER indicated by the base station, where The base station performs superposition transmission with the first UE and the at least one second UE paired with the base station, wherein the value of the at least one second BLER is different from the value of the first BLER.

16. The first UE of clause 15, wherein the second CSI comprises a second CQI, wherein the second reporting device is configured to: - combine the base station with the at least one second BLER indicated by the base station The second CQI is calculated for the power allocated by the first UE and the at least one second UE.

17. The first UE of clause 15, wherein the first UE further comprises: determining means, determining, according to the PMI/RI included in the first CSI, a PMI included in the at least one second CSI / RI; wherein the manner of determining includes any one of: - the PMI / RI included in the at least one second CSI is the same as the PMI / RI included in the first CSI; - the at least one second CSI The included PMI/RI is included in the first CSI Subarray of PMI/RI.

18. The first UE of clause 15, wherein the second CSI only includes the second CQI.

19. The first UE of clause 15, wherein the number of the second CSIs corresponds to the number of the second UEs.

20. The first UE of clause 15, wherein the first UE further comprises a sorting device, configured to: - perform the at least one interference according to a power level of the at least one interference generated by the at least one second UE Sorting; - According to the sorting, the corresponding BLER is sequentially determined from at least one second BLER indicated by the base station, and the corresponding CSI is calculated.

21. The first UE of clause 15, wherein the value of the at least one second BLER is lower than the value of the first BLER.

22. The first UE of clause 15, wherein the first CSI and the at least one second CSI are reported to the base station in a new PUCCH format.

23. The first UE of clause 15, wherein the second CSI comprises a difference between the second CQI and a first CQI included in the first CSI.

24. The first UE of clause 15, wherein the first CSI and the at least one second CSI are reported to the base station in a time division multiplex manner.

25. The first UE of clause 15, wherein the first CSI and the at least one second CSI are reported to the base station in different periods.

26. A base station for facilitating reporting of CSI for overlay transmission, wherein the base station includes: indicating means for indicating a first BLER and at least one second BLER to a corresponding first UE, wherein the at least one The value of the two BLER is different from the value of the first BLER.

27. The base station of clause 26, wherein the base station also comprises: The first configuration device is configured to configure a corresponding MCS for the first UE according to the first CSI and the at least one second CSI reported by the first UE.

28. The base station of clause 26, wherein the base station further comprises: a second configuration device, configured to: according to the at least one second CSI reported by the first UE, and the at least one second CSI The CSI reported by the at least one second UE configures a corresponding MCS for the at least one second UE, respectively.

29. A system for implementing a CSI for overlay transmission reporting, comprising the first UE of any one of clauses 15 to 25 and the base station of any one of clauses 26 to 28.

S201‧‧‧ steps

S202‧‧‧Steps

Claims (15)

A method for implementing a report channel status indicator (CSI) for overlay transmission in a first user equipment (UE), wherein the method includes: a, according to a first block error ratio (BLER) indicated by a corresponding base station, Reporting, to the base station, a first CSI corresponding to the first BLER; b reporting, to the base station, at least one second CSI corresponding to the at least one second BLER according to the at least one second BLER indicated by the base station And performing superposition transmission between the base station and the first UE and the at least one second UE paired with the base station, wherein the value of the at least one second BLER is different from the value of the first BLER. The method of claim 1, wherein the second CSI comprises a second CQI, wherein the step b comprises: according to the at least one second BLER indicated by the base station, and combining the base station with the first UE and the at least one The second CQI is calculated by the power allocated by the UE. The method of claim 1, wherein the method further comprises: determining, according to the PMI/RI included in the first CSI, a PMI/RI included in the at least one second CSI; wherein the determining manner includes any one of the following The PMI/RI included in the at least one second CSI is the same as the PMI/RI included in the first CSI; and the PMI/RI included in the at least one second CSI is included in the first CSI. Subarray of PMI/RI. The method of claim 1, wherein the second CSI only includes the second CQI. A method for assisting in implementing CSI for overlay transmission in a base station, where The method includes: indicating a first BLER and at least one second BLER to the corresponding first UE, where the value of the at least one second BLER is different from the value of the first BLER. The method of claim 5, wherein the method further comprises: configuring a corresponding MCS for the first UE according to the first CSI and the at least one second CSI reported by the first UE. The method of claim 5, wherein the method further comprises: according to the at least one second CSI reported by the first UE, and the CSI reported by the at least one second UE corresponding to the at least one second CSI, respectively The at least one second UE configures a corresponding MCS. A first UE that implements reporting CSI for overlay transmission, where the first UE includes: a first reporting device, configured to report, to the base station, a first BLER corresponding to the first BLER indicated by the corresponding base station a first CSI; a second reporting device, configured to report, to the base station, at least one second CSI corresponding to the at least one second BLER according to the at least one second BLER indicated by the base station, where the base station and the base station And performing superposition transmission between the first UE and the at least one second UE paired thereto, wherein the value of the at least one second BLER is different from the value of the first BLER. The first UE of claim 8, wherein the second CSI includes a second CQI, wherein the second reporting device is configured to: according to the at least one second BLER indicated by the base station, and combine the base station with the first UE And calculating the second CQI by the power allocated by the at least one second UE. The first UE of claim 8, wherein the first UE further includes: determining means, determining, according to the PMI/RI included in the first CSI, the One less PMI/RI included in the second CSI; wherein the manner of determining includes any one of the following: the PMI/RI included in the at least one second CSI is the same as the PMI/RI included in the first CSI; The PMI/RI included in the at least one second CSI is a sub-array of PMI/RI included in the first CSI. The first UE of claim 8, wherein the second CSI only includes the second CQI. A base station for facilitating reporting CSI for overlay transmission, wherein the base station includes: indicating means for indicating a first BLER and at least one second BLER to a corresponding first UE, wherein the value of the at least one second BLER Different from the value of the first BLER. The base station of claim 12, wherein the base station further includes: a first configuration device, configured to configure, for the first UE, the first UE according to the first CSI and the at least one second CSI reported by the first UE MCS. The base station of claim 12, wherein the base station further comprises: a second configuration device, configured to: according to the at least one second CSI reported by the first UE, and at least one corresponding to the at least one second CSI The CSI reported by the second UE configures the corresponding MCS for the at least one second UE, respectively. A system for implementing CSI for overlay transmission reporting, comprising a first UE as claimed in any one of claims 8 to 11 and a base station as claimed in any one of claims 12 to 14.