HK1234227B - User equipment and methods for csi enhancements using interference cancellation and suppression receivers - Google Patents

Description

User equipment and method for CSI enhancement using interference cancellation and suppression receiver

Priority claim

This application claims the benefit of priority to U.S. patent application serial number 14/573,164, filed on December 17, 2014, and claims the benefit of priority to U.S. provisional patent application serial number 62/015,903, filed on June 23, 2014, both of which are incorporated herein by reference in their entireties.

Technical Field

Embodiments relate to wireless communications. Some embodiments relate to cellular networks, including networks operating according to 3GPP LTE and LTE-A standards. Some embodiments relate to small cell deployments. Some embodiments relate to 5G cellular networks.

Background Art

In LTE (Long Term Evolution, including Long Term Evolution Advanced or LTE-A), base stations (evolved Node B or eNB in LTE terminology) perform channel-dependent scheduling and link adaptation, where transmission parameters such as transmit power and modulation and coding scheme (MCS) used to send data to terminals (user equipment or UE in LTE terminology) are dynamically adjusted. To this end, the UE provides channel state information (CSI) to the eNB in the form of CSI reports. Accurate reporting of CSI by the UE is essential for effective link adaptation in the downlink. The main focus of this disclosure is on how UEs with NAICS (Network Assisted Interference Cancellation and Suppression) receivers can perform CSI reporting.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 illustrates an example of components in an LTE system according to some embodiments.

FIG. 2 illustrates an example of a procedure followed by a NAICS capable UE to derive a channel quality indication in accordance with some embodiments.

DETAILED DESCRIPTION

The following description and accompanying drawings sufficiently illustrate specific embodiments to enable those skilled in the art to practice them. Other embodiments may include structural, logical, electrical, process, and other variations. Portions or features of some embodiments may be included in or substituted for portions and features of other embodiments. The embodiments set forth in the claims encompass all available equivalents of those claims.

In order to increase the capacity of LTE networks, heterogeneous networks that implement cell-split gains and MU-MIMO (Multi-User Multiple Input Multiple Output) techniques have been adopted. In both cases, co-channel interference from inter-cell or co-scheduled intra-cell users can be the main limiting factor for achieving higher network capacity. In conventional Release 11 systems, interference at the terminal (called user equipment or UE in LTE terminology) is mitigated by using coordinated multi-point technology (CoMP) at the transmitting base station (i.e., evolved Node B or eNB in LTE terminology). However, it has been shown that interference mitigation at the UE side by taking into account the spatial characteristics of the interference can also provide gains in terms of spectral efficiency. An example is the so-called MMSE-IRC (Minimum Mean Square Error Interference Cancellation) receiver.

Further enhancement of interference mitigation on the receiver side can be achieved by using more advanced receiver algorithms that can exploit additional information about the interference structure. For example, the receiver can estimate interference parameters such as transmission mode, interference presence, and modulation and coding scheme (MCS) to facilitate advanced interference cancellation and suppression using maximum likelihood (ML) techniques or symbol level interference cancellation (SLIC) techniques. To assist in the operation of such receivers, the eNB can provide the UE with higher layer signaling assistance related to the parameters of the interfering signal (power offset subset, transmission mode set, resource allocation, and precoding granularity used in neighboring cells). Such receivers can be referred to as interference aware (IA) receivers or (NAICS) receivers.

For the purpose of dynamic channel-dependent scheduling and link adaptation, the UE provides channel state information (CSI) to the eNB in the form of CSI reports. The following describes measures that enable UEs with NAICS receivers to perform CSI reporting more accurately.

Figure 1 shows an example of components of an LTE network consisting of a UE 100 and a serving eNB 200, which provides downlink (DL) and uplink (UL) resource allocations for the UE 100. The UE 100 includes processing circuitry 101 connected to a radio frequency (RF) transceiver 102 for providing an LTE interface. The serving eNB 200 includes processing circuitry 201 connected to an RF transceiver 202 for providing an LTE interface. Each of these transceivers is connected to an antenna 50. The processing circuitry in each device may implement a physical layer, which uses the RF transceiver to transmit and receive signals over a wireless medium, and a medium access control (MAC) layer, which controls access to the medium. The processing circuitry of the UE may implement a NAICS receiver. The processing circuitry of the UE may include memory arranged to configure various components of the UE to perform the operations described herein.

FIG1 also shows a neighboring eNB 300, which serves a geographically adjacent cell. Serving eNB 200 and neighboring eNB 300 can communicate via an X2 interface and time-synchronize their respective downlink transmissions. The figure illustrates a scenario in which the downlink transmission of neighboring eNB 300 may interfere with the downlink transmission of serving eNB 200 to UE 100. Processing circuitry 101 of UE 100 may be configured with NAICS capability and further configured to derive CSI taking NAICS capability into account, as described below.

The LTE downlink transmission scheme is based on Orthogonal Frequency Division Multiple Access (OFDMA), which converts a single wideband frequency-selective channel into multiple frequency-flat subchannels. LTE utilizes multiple antennas for downlink transmission, and a specific multi-antenna transmission scheme can be described here as a mapping from the output of data modulation to a set of antenna ports. The input to the antenna mapping consists of modulation symbols (e.g., QPSK, 16QAM, 64QAM) corresponding to one or two transport blocks of a transmission time interval (TTI), where a transport block refers to how data is organized in the transmission channel between the Medium Access Control (MAC) layer and the physical layer of the LTE radio access protocol stack. The output of the antenna mapping is a set of symbols for each antenna port. These symbols are then applied to the OFDM modulator and mapped to the resource elements (REs) corresponding to that antenna port in the OFDM time-frequency grid. The REs are organized into resource blocks (RBs), and downlink resources are allocated to UEs by the eNB on a per-RB basis.

The different multi-antenna transmission schemes used in LTE correspond to different transmission modes, with ten currently defined. These transmission modes are referred to as TM1-TM10, and they differ in the specific structure of the antenna mapping, which reference signals are assumed for demodulation, and how the CSI is acquired by the UE and fed back to the eNB.

To obtain the CSI information to be sent to the eNB, the UE utilizes downlink reference signals (RS), which are predefined signals that occupy specific resource elements within the downlink time-frequency grid. The LTE specification includes several types of downlink reference signals that differ in how they are transmitted and intended to be used. One RS framework used in LTE is based on cell-specific RS (CRS), where the CRS sequence transmitted on each subframe of resources determined by the cell ID of the serving cell is spread across the entire transmission bandwidth and subframe duration. CRS is intended for CSI estimation and feedback, as well as demodulation of the downlink physical channel. Another RS framework introduced in Release 10 provides separate CSI-RS for CSI estimation and feedback, and a separate demodulation RS (DM-RS) for demodulation. CSI-RS is transmitted across the entire bandwidth with a configurable periodicity and at a relatively low density, while DM-RS is transmitted at a higher density but only in resource blocks (RBs) allocated to specific UEs. Release 11 further introduces a tool for better interference measurement in the CSI-RS framework, called CSI-IM (CSI-Interference Management) resources. Such CSI-IM resources can include CSI-RS transmitted by the eNB at zero power.

The UE sends CSI information to its serving eNB in the form of CSI reports, which can be sent periodically or aperiodically upon request from the eNB. The CSI report includes a channel quality indicator (CQI), which is defined by the LTE specification as the highest CQI index that will result in a BLER (block error rate) of 10% for a PDSCH (physical data shared channel) transport block transmission. As described in Section 7.2.3 of TS 36.213:

Based on an unrestricted observation interval in time and frequency, the UE shall derive, for each CQI value reported in uplink subframe n, the highest CQI index between 1 and 15 in Table 7.2.3-1 that satisfies the following condition, or CQI index 0 if CQI index 1 does not satisfy this condition:

A single PDSCH transport block with a combination of modulation scheme and transport block size corresponding to the CQI index, and occupying a set of downlink physical resource blocks called CSI reference resources, can be received with a transport block error probability not exceeding 0.1.

The above CQI definition implies that the reported CQI index should include all UE receiver processing capabilities, including the NAICS capability for canceling and suppressing interference on the CSI reference resources. While the CQI requirements for NAICS can be easily met for intra-cell interference (SU-MIMO) because the UE knows the interfering signal parameters, accurately reporting CQI with a NAICS receiver is more problematic for inter-cell interference. The following describes measures that can be used to enable NAICS-capable UEs to report CSI more accurately.

In a typical UE implementation, inter-cell interference (CQI) is measured on the serving cell CRS or CSI-IM REs of the CSI reference resources. In principle, this approach can be used for NAICS receivers. However, for NAICS receivers, the parameter estimation reliability requirements are more stringent, and the lack of available REs within a PRB pair makes reliable estimation of inter-cell interference signal parameters (e.g., modulation order, precoding matrix indicator, transmit power) for NAICS more problematic. For example, in TM1-9, the REs available for parameter estimation are limited to 12 REs per PRB pair, and for TM10, to 4 REs per PRB pair. Potentially, the number of REs used for interference estimation could be increased, but such an enhancement (without a significant performance loss due to the additional overhead) may not be feasible for CSI-IM-based approaches. In one embodiment, the use of CSI-IM is extended to TM1-9, and a larger number of REs (e.g., 8, 12, 16, etc.) is used per CSI-IM resource. It should be noted that in certain CRS configurations preferred for NAICS operation (eg, colliding CRS of serving and interfering cells), the interference samples measured on the serving cell CRS RE may not reflect the actual interference conditions seen on the PDSCH.

In another embodiment, the UE utilizes its NAICS receiver capabilities to measure interference in order to calculate the CQI. The NAICS receiver mitigates downlink interference by utilizing information available to it, which may include parameters of the signal received from the neighboring eNB via higher-layer signaling, the interfering channel, and signal parameters related to the interfering signal detected from the received signal itself (e.g., symbol alphabet, modulation order, and transmit power). During PDSCH demodulation, the UE, with the help of higher-layer signaling, can estimate the interfering channel from the neighboring cell's reference signals (e.g., CRS (TM1-6 on the neighboring cell) and/or DM-RS (TM7-10 on the neighboring cell)). By demodulating these reference signals, the UE can estimate the channel corresponding to the interfering signal transmitted by the neighboring cell. During PDSCH demodulation, it can be determined which reference signal, CRS or DM-RS, the UE should use for the estimation. For example, for each PRB pair, the UE may first attempt to detect the presence of the neighboring cell's DM-RS and, if DM-RS is not present, use the CRS. To estimate the interfering signal parameters, the UE may perform the following process during PDSCH demodulation. On the RBs of the scheduled PDSCH, the UE observes a mixture of useful signals (with known parameters from the control signaling of the serving cell) and interference signals (with unknown parameters). For each RB, the UE scans the possible parameters (e.g., modulation schemes) that can be used in the interfering cell signal and tries to find the most likely one that maximizes a specific metric (e.g., likelihood function). When the RB is outside the scheduled PDSCH resource allocation, the estimate may not be accurate because the UE will not know the parameters of the signals from both the interfering cell and the serving cell.

In one embodiment, the UE first measures interference to calculate the CQI from a reference signal sent in a conventional manner. That is, interference is measured as noise on a reference signal (e.g., CRS or CSI-RS, depending on the transmission mode) by calculating the residual after subtracting the reference signal from the received signal in the appropriate resource element. The UE can also make this initial interference measurement using CSI-IM resources if operating in TM10. The interference measurement (or calculated CQI) is then modified based on the UE's NAICS receiver capabilities by determining the interfering signal parameters and the interfering channel during PDSCH demodulation as described in the previous paragraph.

In another embodiment, the CSI reference resource definition is extended to the UE's scheduled PDSCH resource allocation (e.g., corresponding to a C-RNTI or cell radio network temporary identifier). The CSI reporting (including CQI) for such CSI reference resources is then calculated based on the interference signal parameters estimated from the received PDSCH and the NAICS receiver capabilities. If there is no scheduled PDSCH on the CSI reference resource, the UE can report CQI in an unmodified manner, such as based on the MMSE-IRC receiver capabilities (i.e., the UE is not expected to use higher layer signaling assistance for NAICS receivers in the CQI calculation). This helps the receiver to tailor CQI reporting based on the actual interference conditions and the receiver processing capabilities for interference cancellation and mitigation.

In another embodiment, the definition of CSI reference resources for CQI calculation for a UE with a NAICS receiver is extended only to the resource allocation occupied by the scheduled PDSCH. Thus, during PDSCH demodulation, the NAICS receiver estimates the parameters of the interfering signal and calculates an appropriate MCS that results in a target BLER of 10% for the CSI reference resources associated with the PDSCH resource allocation. In the event that no PDSCH resources are available for CSI reference resources, the CSI calculation at the UE can fall back to the conventional CSI-IM or CRS-based process. In this case, the UE can refer to a conventional MMSE-IRC receiver to calculate CQI, without considering the higher-layer signaling provided to enable NAICS processing. That is, if the CSI reference resources do not completely overlap with the scheduled PDSCH in time and frequency, the UE will not be expected to use NAICS higher-layer signaling for CQI calculation. If the time-frequency resources of the CSI reference resources are a subset of the resources allocated to the PDSCH, then the CSI reference resources completely overlap with the PDSCH.

In another embodiment, the CSI reference resource definition will be limited to the resource allocation of the scheduled PDSCH. In this case, the UE will provide a CSI report for this CSI reference resource. In another embodiment, the CSI reference resource definition will be extended to the resource allocation of the scheduled PDSCH, and the UE will provide a delta MCS report. The delta MCS report will indicate the difference between the actual assigned MCS and the highest MCS estimated at the UE that meets the target transport block error rate (BLER) of no more than 10%.

Figure 2 shows an example of the process followed by a NAICS-capable UE to derive a CQI for inclusion in a CSI report generated periodically or in response to a request from a serving eNB. In stage S1, the UE derives the CQI based on a reference signal received from the eNB. In stage S2, the UE determines whether a PDSCH allocation is included in the CSI reference resources. If "no," the UE calculates and sends a CSI report containing the derived CQI in stage S3. If "yes," the UE modifies the derived CQI in stage S4 using information related to parameters of the interfering channel and/or interfering signal derived during PDSCH demodulation. In stage S5, the CSI report containing the modified CQI is sent to the eNB.

Example Embodiments

In Example 1, a method of operating a UE (user equipment) includes: demodulating a PDSCH (physical data shared channel) received from an eNB; calculating a channel quality indicator (CQI) based on a reference signal received from the eNB; and modifying the CQI by estimating interference during PDSCH demodulation using network-assisted interference and cancellation (NAICS) signaling received from the eNB. The UE may utilize a NAICS receiver to demodulate the PDSCH.

In Example 2, the subject matter of Example 1 may optionally include modifying the CQI based on interference estimation performed during PDSCH demodulation by estimating the interference contribution channel from a reference signal present in the PDSCH allocation, and estimating the interference signal parameters within the PDSCH by assisting with higher layer signaling from neighboring cells related to the parameters of the interference signal and scanning possible parameters to determine the parameters that are most likely to have been received.

In Example 3, the subject matter of any of the preceding Examples may optionally include sending a CSI (channel state information) report including the modified CQI to the eNB.

In Example 4, the subject matter of any of the preceding examples may optionally include sending a CSI report containing a modified CQI to the eNB if the CSI (channel state information) reference resources defined by the eNB completely overlap with the resource allocation of the PDSCH in time and frequency.

In Example 5, the subject matter of any of the foregoing examples may optionally include: if the CSI reference resources defined by the eNB do not completely overlap with the resource allocation of the PDSCH, sending a CSI report that does not include the modified CQI to the eNB.

In Example 6, the subject matter of any of the preceding examples may optionally include sending a CSI report including a modified CQI to the eNB when the CSI (channel state information) reference resource definition is extended to include resource allocation for PDSCH.

In Example 7, the subject matter of any of the preceding Examples may optionally include sending a CSI report with an unmodified CQI to the eNB if there is no scheduled PDSCH on the CSI reference resource.

In Example 8, the subject matter of any of the preceding Examples may optionally include sending a CSI report containing a modified CQI to the eNB when the CSI reference resource definition is limited to resource allocation of the PDSCH.

In Example 9, the subject matter of any of the preceding examples may optionally include sending a CSI report containing a modified CQI to the eNB in a case where the CSI (channel state information) reference resource definition is extended to the resource allocation of the PDSCH, wherein the CSI report contains the modified CQI as a delta MCS (modulation and coding scheme), and the delta MCS indicates the difference between the actually allocated MCS and the highest MCS estimated at the UE that meets the target BLER (block error rate).

In Example 10, a UE includes a wireless transceiver for communicating with an eNB (evolved Node B) and a processing circuit for performing any one of the methods described in Examples 1-9.

In Example 11, a non-transitory computer-readable storage medium includes instructions, the instructions being executed by one or more processors of a UE to perform operations, the operations configuring the UE to perform any of the methods described in Examples 1-9.

The above-mentioned detailed description includes reference to the accompanying drawings, which form a part of the detailed description. The accompanying drawings show specific embodiments that can be implemented by way of illustration. These embodiments are also referred to as "examples" in this article. These examples may include elements other than those shown or described. However, examples containing the elements shown or described can also be expected. In addition, with respect to a specific example (or one or more aspects thereof), or with respect to other examples (or one or more aspects thereof) shown or described herein, examples (or one or more aspects thereof) using any combination or permutation of those elements shown or described can also be expected.

The publications, patents, and patent documents mentioned in this document are incorporated herein by reference in their entirety, as if individually incorporated by reference. In the event of any inconsistency between the usages of this document and those documents incorporated by general reference, the usage in the incorporated references supplements that of this document; for any conflicting inconsistencies, the usage in this document takes precedence.

In this document, the use of the terms "a" or "an", as is common in patent documents, includes one or more than one, independent of any other instance or usage of "at least one" or "one or more". In this document, the term "or" is used to refer to a non-exclusive "or" so that "A or B" includes "A but not B", "B but not A", and "A and B", unless otherwise indicated. In the following claims, the terms "including" and "in which" are used as the plain English equivalents of the respective terms "comprising" and "wherein". In addition, in the following claims, the terms "including" and "comprising" are open-ended, that is, a system, apparatus, article, combination, or process may include elements other than the elements listed following such term in a claim and still be considered to fall within the scope of the claim. Furthermore, in the following claims, the terms "first", "second", and "third", etc., are used merely as labels and are not intended to imply a numerical order to their objects.

In some embodiments, the UE may be part of a portable wireless communication device, such as a personal digital assistant (PDA), a laptop or portable computer with wireless communication capabilities, a web tablet, a wireless phone, a smart phone, a wireless headset, a pager, an instant messaging device, a digital camera, an access point, a television, a medical device (such as a heart rate monitor, a blood pressure monitor, etc.), a wearable device, or other device that can wirelessly receive and/or send information. In some embodiments, the mobile device may include one or more of a keyboard, a display, a non-volatile memory port, multiple antennas, a graphics processor, an application processor, a speaker, and other mobile device components. The display may be an LCD screen including a touch screen.

The antennas may include one or more directional or omnidirectional antennas, including, for example, dipole antennas, monopole antennas, patch antennas, loop antennas, microstrip antennas, or other types of antennas suitable for RF signal transmission. In some multiple-input multiple-output (MIMO) embodiments, the antennas may be equally spaced to exploit spatial diversity and the different channel characteristics that may be obtained.

One or more functional elements of a UE or eNB may be combined and implemented by a combination of software-configured elements (e.g., a processing element including a digital signal processor (DSP)) and/or other hardware elements. For example, some elements may include one or more microprocessors, DSPs, field programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), radio frequency integrated circuits (RFICs), and combinations of various hardware and logic circuits for performing at least the functions described herein. In some embodiments, a functional element may refer to one or more processes operating on one or more processing elements.

The embodiments may be implemented in one of hardware, firmware, and software, or in a combination thereof. The embodiments may also be implemented as instructions stored on a computer-readable storage medium, which may be read and executed by at least one processor to perform the operations described herein. A computer-readable storage medium may include any non-transient mechanism for storing information in a machine (e.g., computer) readable form. For example, a computer-readable storage medium may include a read-only memory (ROM), a random access memory (RAM), a magnetic disk storage medium, an optical storage medium, a flash memory device, and other storage devices and media. In these embodiments, one or more processors may be configured with instructions for performing the operations described herein.

In some embodiments, the UE or eNB ( FIG. 1 ) may be configured to transmit and/or receive orthogonal frequency division multiplexing (OFDM) communication signals over a multi-carrier communication channel in accordance with orthogonal frequency division multiple access (OFDMA) techniques. OFDM signals may include multiple orthogonal subcarriers. In some broadband multi-carrier embodiments, the UE and eNB may be part of a cellular broadband wireless access (BWA) network communication network (e.g., a 3rd Generation Partnership Project (3GPP) Universal Terrestrial Radio Access Network (UTRAN) Long Term Evolution (LTE) or LTE communication network), although the scope of the present invention is not limited thereto.

In some embodiments, the UE or eNB may be configured to receive signals transmitted using one or more other modulation techniques, such as spread spectrum modulation (e.g., direct sequence code division multiple access (DS-CDMA) and/or frequency modulation code division multiple access (FH-CDMA)), time division multiplexing (TDM) modulation, and/or frequency division multiplexing (FDM) modulation, but the scope of the embodiments is not limited in this regard.

The above description is intended to be illustrative, not restrictive. For example, the above examples (or one or more aspects thereof) may be used in combination with other examples. Other embodiments may be used, for example, after a person skilled in the art reads the above description. The abstract is to allow the reader to quickly identify the nature of the technical disclosure, for example to comply with 37 C.F.R. Section 1.72(b) of the U.S. federal court. It should be understood that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the above-mentioned specific embodiments, various features may be combined together to make the disclosure smooth. However, the claims may not state every feature disclosed herein, as the embodiments may have a subset of the features. In addition, the embodiments may include fewer features than disclosed in a particular example. Therefore, the following claims are hereby incorporated into the specific embodiments, with one claim representing itself as a separate embodiment. The scope of the embodiments disclosed herein will be determined with reference to the appended claims together with the full scope of equivalents to which these claims are entitled.

Claims (13)

1. A user equipment (UE), comprising: A wireless transceiver used to communicate with an eNB (evolved node B); Processing circuitry, used for: Demodulate the PDSCH (Physical Data Sharing Channel) received from the eNB; Based on the reference signal received from the eNB, the Channel Quality Indicator (CQI) is calculated; and The CQI is modified by estimating interference during PDSCH demodulation using Network Assisted Interference and Cancellation (NAICS) signaling received from the eNB. The processing circuit modifies the CQI based on interference estimation performed during PDSCH demodulation through the following steps: The interference channel is estimated from the reference signal present in the PDSCH allocation, and the interference signal parameters within the PDSCH are estimated by using higher-layer signaling related to the parameters of the interference signal from neighboring cells and scanning possible parameters to determine the parameters most likely to have been received. The processing circuit configures the transceiver as follows: If the CSI (Channel State Information) reference resources defined by the eNB completely overlap with the resource allocation of the PDSCH in both time and frequency, a CSI report containing the modified CQI is sent to the eNB; and If the CSI reference resources defined by the eNB do not completely overlap with the resource allocation of the PDSCH, a CSI report with unmodified CQI is sent to the eNB. 2. The UE as claimed in claim 1, wherein the processing circuit configures the transceiver to send a CSI report containing a modified CQI to the eNB when the CSI (Channel State Information) reference resource definition is extended to include resource allocations containing PDSCH. 3. The UE as claimed in claim 2, wherein if there is no scheduled PDSCH on the CSI reference resource, the processing circuit configures the transceiver to send a CSI report to the eNB that does not contain the modified CQI. 4. The UE as claimed in claim 1, wherein the processing circuit configures the transceiver to send a CSI report containing a modified CQI to the eNB when the CSI (Channel State Information) reference resource definition is limited to the resource allocation of PDSCH. 5. The UE of claim 1, wherein the processing circuitry configures the transceiver to: send a CSI report containing a modified CQI to the eNB when the CSI (Channel State Information) reference resource definition is extended to the resource allocation of PDSCH, wherein the CSI report contains the modified CQI as a delta MCS (Modulation and Coding Scheme), the delta MCS indicating the difference between the actually allocated MCS and the highest MCS estimated at the UE that satisfies the target BLER (Block Error Rate). 6. A method of operating a user equipment (UE), comprising: Demodulate the PDSCH (Physical Data Sharing Channel) received from the eNB; Based on the reference signal received from the eNB, the Channel Quality Indicator (CQI) is calculated; and The CQI is modified by estimating interference during PDSCH demodulation using Network Assisted Interference and Cancellation (NAICS) signaling received from the eNB. The method further includes modifying the CQI based on interference estimation performed during PDSCH demodulation via the following steps: The interference channel is estimated from the reference signal present in the PDSCH allocation, and the interference signal parameters within the PDSCH are estimated by using higher-layer signaling related to the parameters of the interference signal from neighboring cells and scanning possible parameters to determine the parameters most likely to have been received. The method further includes: If the CSI (Channel State Information) reference resources defined by the eNB completely overlap with the resource allocation of the PDSCH in both time and frequency, a CSI report containing the modified CQI is sent to the eNB; and If the CSI reference resources defined by the eNB do not completely overlap with the resource allocation of the PDSCH, a CSI report with unmodified CQI is sent to the eNB. 7. The method of claim 6, further comprising: sending a CSI report containing the modified CQI to the eNB when the CSI (Channel State Information) reference resource definition is extended to include resource allocation of PDSCH. 8. The method of claim 7, further comprising: if there is no scheduled PDSCH on the CSI reference resource, sending a CSI report to the eNB that does not contain the modified CQI. 9. The method of claim 6, further comprising: sending a CSI report containing a modified CQI to the eNB when the CSI (Channel State Information) reference resource definition is limited to the resource allocation of PDSCH. 10. The method of claim 6, further comprising: sending a CSI report containing a modified CQI to the eNB when the CSI (Channel State Information) reference resource definition is extended to the resource allocation of the PDSCH, wherein the CSI report contains the modified CQI as a delta MCS (Modulation and Coding Scheme), the delta MCS indicating the difference between the actually allocated MCS and the highest MCS estimated at the UE that satisfies the target BLER (Block Error Rate). 11. A non-transitory computer-readable storage medium storing instructions that are executed by one or more processors of a user equipment to perform operations that configure the UE (user equipment) to perform any of the methods described in claims 6-10. 12. A user equipment (UE), comprising: A unit used to demodulate the PDSCH (Physical Data Sharing Channel) received from the eNB; A unit for calculating Channel Quality Indicator (CQI) based on a reference signal received from the eNB; and A unit for modifying the CQI by estimating interference during PDSCH demodulation using Network Assisted Interference and Cancellation (NAICS) signaling received from the eNB. The UE further includes a unit for modifying the CQI based on interference estimation performed during PDSCH demodulation via the following steps: The interference channel is estimated from the reference signal present in the PDSCH allocation, and the interference signal parameters within the PDSCH are estimated by using higher-layer signaling related to the parameters of the interference signal from neighboring cells and scanning possible parameters to determine the parameters most likely to have been received. The UE further includes: A unit for sending a CSI report containing a modified CQI to the eNB if the CSI (Channel State Information) reference resources defined by the eNB completely overlap with the resource allocation of the PDSCH in time and frequency; and A unit for sending a CSI report with unmodified CQI to the eNB if the CSI reference resources defined by the eNB do not completely overlap with the resource allocation of the PDSCH. 13. The UE of claim 12, further comprising a unit for sending a CSI report containing a modified CQI to the eNB when the CSI (Channel State Information) reference resource definition is extended to include resource allocation containing PDSCH.