HK1234227A1 - 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 requirement

This application claims the benefit of priority from U.S. patent application serial No.14/573,164 filed on day 12 and 17 of 2014 and claims the benefit of priority from U.S. provisional patent application serial No.62/015,903 filed on day 6 and 23 of 2014, both of which are incorporated herein by reference in their entireties.

Technical Field

Embodiments pertain to wireless communications. Some embodiments relate to cellular networks, including networks operating according to the 3gpp LTE and LTE-a standards. Some embodiments relate to small cell deployment. Some embodiments relate to 5G cellular networks.

Background

In LTE (long term evolution, including long term evolution advanced or LTE-a), a base station (evolved node B or eNB in LTE terminology) performs channel dependent scheduling and link adaptation, wherein transmission parameters, such as transmission power and Modulation and Coding Scheme (MCS), for transmitting data to a terminal (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 a CSI report. Accurate reporting of CSI by the UE is essential for efficient link adaptation on the downlink. The main focus of the present disclosure is how a UE with a NAICS (network assisted interference cancellation and suppression) receiver can perform CSI reporting.

Drawings

Fig. 1 illustrates an example of components in an LTE system, in accordance with some embodiments.

Figure 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 the annexed drawings set forth in detail certain illustrative embodiments sufficiently to enable those skilled in the art to practice them. Other embodiments may include structural, logical, electrical, process, and other changes. Portions or features of some embodiments may be included in or substituted for those of others. Embodiments set forth in the claims encompass all available equivalents of those claims.

In order to increase the capacity of the LTE network, a heterogeneous network implementing a cell-split gain and MU-MIMO (multi-user multiple input multiple output) technology has been adopted. In both cases, co-channel interference from inter-cell or co-scheduled intra-cell users may be the main limiting factor for achieving higher network capacity. In conventional Release 11 systems, interference at a terminal (referred to as user equipment or UE in LTE terminology) is mitigated by using coordinated multipoint technology (CoMP) at the transmitting base station (i.e., evolved node B or eNB in LTE terminology). However, it has been demonstrated that interference mitigation at the UE side by taking into account the spatial characteristics of the interference may also provide gains in terms of spectral efficiency. One example is the so-called MMSE-IRC (minimum mean square error interference suppression) receiver.

Further enhancement of interference mitigation at the receiver side can be achieved by using more advanced receiver algorithms that can exploit additional information about the interference structure. For example, a receiver may estimate interference parameters such as transmission mode, interference presence, and Modulation Coding Scheme (MCS) to facilitate advanced interference cancellation and suppression using Maximum Likelihood (ML) techniques or Symbol Level Interference Cancellation (SLIC) techniques. To facilitate operation of such receivers, the eNB may provide higher layer signaling assistance to the UE regarding parameters of the interfering signal (subset of power offsets used in neighboring cells, set of transmission modes, resource allocation, and precoding granularity). Such receivers may 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 report CSI more accurately.

Fig. 1 shows an example of components of an LTE network consisting of a UE100 and a serving eNB 200, the serving eNB 200 providing Downlink (DL) resource allocation and Uplink (UL) resource allocation for the UE 100. The UE100 includes processing circuitry 101 connected to a Radio Frequency (RF) transceiver 102 for providing an LTE interface. The serving eNB 200 comprises processing circuitry 201 connected to an RF transceiver 202 for providing an LTE interface. Each transceiver in these devices is connected to an antenna 50. The processing circuitry in each device may implement a physical layer that uses an RF transceiver to transmit and receive signals over a wireless medium and a Medium Access Control (MAC) layer that 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 elements of the UE to perform the operations described herein.

Also shown in fig. 1 is a neighboring eNB 300, which serves geographically neighboring cells. The serving eNB 200 and the neighboring eNB 300 may communicate via an X2 interface and time synchronize their respective downlink transmissions. The figure shows a situation where the downlink of a neighbouring eNB 300 may interfere with the downlink transmission of the serving eNB 200 to the UE 100. The processing circuitry 101 of the UE100 may be configured with NAICS capability and further configured to derive CSI taking into account the NAICS capability, 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 sub-channels. LTE utilizes multiple antennas for downlink transmission, where a particular multi-antenna transmission scheme may be described 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 a transport 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 an OFDM modulator and mapped to Resource Elements (REs) in the OFDM time-frequency grid corresponding to the antenna port. The REs are organized into Resource Blocks (RBs), and downlink resources are allocated by the eNB to the UEs according to the RBs.

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

In order to acquire CSI information to be transmitted to the eNB, the UE utilizes a downlink Reference Signal (RS), which is here a predefined signal occupying a specific resource element within the downlink time-frequency grid. The LTE specification includes several types of downlink reference signals that differ in the way they are transmitted and intended for use. One RS framework (frame) 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 over the entire transmission bandwidth and subframe duration. CRS is intended for CSI estimation and feedback, as well as demodulation of downlink physical channels. Another RS framework introduced in Release 10 provides separate CSI-RS for CSI estimation and feedback, and separate demodulation RS (DM-RS) for demodulation. The CSI-RS is transmitted over the entire bandwidth with a configurable periodicity and at a relatively low density, while the DM-RS is transmitted at a higher density but only in Resource Blocks (RBs) allocated to particular UEs. Release 11 further introduces a tool in the CSI-RS framework for better measuring interference, called CSI-IM (CSI-interference management) resource. Such CSI-IM resources may include CSI-RSs that the eNB transmits at zero power.

The UE sends CSI information to its serving eNB in the form of CSI reports, which may be sent periodically, and aperiodically when requested by the eNB. The CSI report includes a Channel Quality Indication (CQI), where the CQI is defined by the LTE specification as the highest CQI index that will result in a 10% BLER (block error rate) for PDSCH (physical data shared channel) transport block transmission. As recited in TS 36.213, section 7.2.3:

based on the non-limiting observation interval in time and frequency, the UE should derive, for each CQI value reported in uplink subframe n, the highest CQI index between 1 and 15 in tables 7.2.3-1 that satisfies the following condition, or CQI index 0 if CQI index 1 does not satisfy the condition:

a single PDSCH transport block having 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 NAICS capabilities for cancelling and suppressing interference on the CSI reference resource. Although the CQI requirement for NAICS can be easily met for intra-cell interference (SU-MIMO) since the UE knows the interfering signal parameters, it is more problematic for inter-cell interference to report the CQI accurately with the NAICS receiver. The following describes measures that can be used to make a UE with NAICS capability report CSI more accurately.

In a typical UE implementation, the inter-cell interference of the CQI is measured on the serving cell CRS or CSI-IM REs of the CSI reference resource. In principle, this method can be used in NAICS receivers. However, the parameter estimation reliability requirements for parameter estimation are more stringent for NAICS receivers, and the lack of available REs within a PRB pair may make reliable estimation of inter-cell interference signal parameters (e.g., modulation order, precoding matrix indication, transmission power) for NAICS more problematic. For example, in TM1-9, the REs available for parameter estimation will be limited to 12 REs per PRB pair, while for TM10, it will be limited to 4 REs per PRB pair. Potentially, the number of REs used for interference estimation may be increased, but such an enhancement (without significant performance loss due to 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 each CSI-IM resource uses a larger number of REs (e.g., 8, 12, 16, etc.). It should be noted that in certain CRS configurations that are preferred for NAICS operation (e.g., colliding CRS of serving and interfering cells), the interference samples measured on the serving cell CRSRE may not reflect the actual interference conditions seen on the PDSCH.

In another embodiment, the UE measures interference with its NAICS receiver capability in order to calculate CQI. The NAICS receiver mitigates downlink interference by utilizing information that may be provided to it, which may include parameters of signals received from neighboring enbs via higher layer signaling, interference-contributing channels, and signal parameters (e.g., symbol letters, modulation order, and transmission power) related to interfering signals detected from the received signals themselves. During PDSCH demodulation, the UE, with the help of higher layer signaling, may estimate the interference contributing channel from the reference signals of the neighboring cells, e.g., CRS (TM 1-6 on the neighboring cell) and/or DM-RS (TM 7-10 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 may be decided which reference signal, CRS or DM-RS, the UE should use for estimation. For example, for each PRB pair, the UE may first attempt to detect the presence of DM-RS of a neighbor cell and use CRS if DM-RS is not present. To estimate the interfering signal parameters, the UE may perform the following procedure during PDSCH demodulation. On RBs of the scheduled PDSCH, the UE observes a mixture of useful signals (with known parameters of control signaling from the serving cell) and interfering signals (with unknown parameters). For each RB, the UE scans for possible parameters (e.g., modulation schemes) that may be used in interfering cell signals and attempts to find the most likely one that maximizes a particular metric (e.g., likelihood function). When the RB is outside the scheduled PDSCH resource allocation, this estimation may not be accurate because the UE will not know the parameters of the signals from both the interfering and serving cells.

In one embodiment, the UE first measures the interference to calculate the CQI from the reference signal sent in the conventional manner. That is, by calculating the residual after subtracting the reference signal from the received signal in the appropriate resource elements, the interference is measured as noise on the reference signal (e.g., CRS or CSI-RS, depending on the transmission mode). The UE may also make this initial interference measurement using CSI-IM resources if operating under TM 10. The interference measurements (or calculated CQI) are then modified according to the NAICS receiver capability of the UE by determining the interfering signal parameters and the interference contributing channels during PDSCH demodulation as described in the previous paragraph.

In another embodiment, the CSI reference resource defines a scheduled PDSCH resource allocation (e.g., corresponding to a C-RNTI or a cell radio network temporary identity) that is extended to the UE. Then, CSI reports (including CQI) for such CSI reference resources are calculated based on interfering signal parameters estimated from the received PDSCH and NAICS receiver capabilities. If there is no scheduled PDSCH on the CSI reference resource, the UE may report the CQI in an unmodified manner, e.g., according to MMSE-IRC receiver capability (i.e., the UE is not expected to use higher layer signaling assistance for the NAICS receiver in the CQI calculation). This facilitates CQI reporting by the receiver depending on the actual interference conditions and the receiver processing capabilities for interference cancellation and suppression.

In another embodiment, the CSI reference resource definition for CQI calculation by 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 computes a suitable MCS that will result in a target BLER of 10% for the CSI reference resources associated with the PDSCH resource allocation. In the case where no PDSCH resources are available for CSI reference resources, the CSI computation at the UE may return to a conventional CSI-IM or CRS based process. In this case, the UE can calculate CQI with reference to a conventional MMSE-IRC receiver, regardless of higher layer signaling provided to enable NAICS processing. That is, if the CSI reference resource does not completely overlap the scheduled PDSCH in time and frequency, the UE will not be expected to use NAICS higher layer signaling for CQI calculation. The CSI reference resources completely overlap the PDSCH if their time-frequency resources are a subset of the resources allocated to 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 CSI reports for such CSI reference resources. In another embodiment, the CSI reference resources define the resource allocation to be extended to the scheduled PDSCH and the UE will provide a delta MCS report. The Delta MCS report will indicate the difference between the actually allocated MCS and the highest MCS estimated at the UE that meets the target transport block error rate (BLER) of no more than 10%.

Fig. 2 shows an example of a procedure followed by a NAICS capable UE for deriving CQI for inclusion in CSI reports generated periodically or in response to a request from a serving eNB. At stage S1, the UE derives a CQI based on receiving a reference signal from the eNB. In stage S2, the UE determines whether the PDSCH allocation is included in the CSI reference resource. If "no", the UE calculates and sends a CSI report containing the derived CQI at stage S3. If "yes," the UE modifies the derived CQI with information on parameters of the interfering channel and/or interfering signal derived during PDSCH demodulation at stage S4. At 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) comprises: demodulating a PDSCH (physical data shared channel) received from an eNB; calculating a Channel Quality Indication (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 demodulate the PDSCH with a NAICS receiver.

In example 2, the subject matter of example 1 can optionally include: modifying the CQI based on interference estimation performed during PDSCH demodulation by: the interference contributing channels are estimated from reference signals present in the PDSCH allocation and the interfering signal parameters within the PDSCH are estimated by using higher layer signaling from neighboring cells related to the parameters of the interfering signals to assist and scan 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 can optionally include: transmitting 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 can optionally include: transmitting a CSI report containing a modified CQI to the eNB if CSI (channel State information) reference resources defined by the eNB completely overlap with resource allocation of a PDSCH in time and frequency.

In example 5, the subject matter of any of the preceding examples can optionally include: transmitting a CSI report without modified CQI to the eNB if the CSI reference resources defined by the eNB do not completely overlap with the resource allocation of the PDSCH.

In example 6, the subject matter of any of the preceding examples can optionally include: transmitting a CSI report including the modified CQI to the eNB in a case where a CSI (channel State information) reference resource definition is extended to include a resource allocation of the PDSCH.

In example 7, the subject matter of any of the preceding examples can optionally include: transmitting a CSI report with unmodified CQI to the eNB if there is no scheduled PDSCH on a CSI reference resource.

In example 8, the subject matter of any of the preceding examples can optionally include: transmitting a CSI report including a modified CQI to the eNB, in case a CSI (channel State information) reference resource definition is limited to a resource allocation of a PDSCH.

In example 9, the subject matter of any of the preceding examples can optionally include: transmitting a CSI report containing a modified CQI as a delta MCS (modulation coding scheme) indicating a difference between an actually allocated MCS and a highest MCS estimated at the UE satisfying a target BLER (Block error Rate) to the eNB in a case where a CSI (channel State information) reference resource definition is extended to a resource allocation of a PDSCH.

In example 10, the UE includes a wireless transceiver to communicate with an eNB (evolved node B) and processing circuitry to perform any of the methods described in examples 1-9.

In example 11, a non-transitory computer-readable storage medium contains instructions for execution by one or more processors of a UE to perform operations that configure the UE to perform any of the methods described in examples 1-9.

The foregoing detailed description includes references to the accompanying drawings, which form a part hereof. The drawings show, by way of illustration, specific embodiments which can be practiced. These embodiments are also referred to herein as "examples". These examples may include elements other than those shown or described. However, examples containing the elements shown or described are also contemplated. Moreover, any combination or permutation of those elements shown or described (or one or more aspects thereof) with respect to a particular example (or one or more aspects thereof), or with respect to other examples shown or described herein (or one or more aspects thereof), is also contemplated.

The publications, patents, and patent documents referred to in this document are incorporated by reference herein in their entirety as if individually incorporated by reference. In the event of inconsistent usages between this document and those documents incorporated by general reference, the usage in the incorporated references is in addition to the usage in this document; for contra-contradictory inconsistencies, the usage in this document takes precedence.

In this document, the use of the terms "a" or "an," as is conventional in patent documents, includes one or more than one, regardless of any other instances or usages of "at least one" or "one or more. In this document, the term "or" is used to refer to a non-exclusive "or" such that "a or B" includes "a instead of B", "B instead of a" and "a and B", unless otherwise specified. In the appended claims, the terms "including" and "in which" are used as the plain-English equivalents of the respective terms "comprising" and "wherein". Furthermore, in the following claims, the terms "comprises" and "comprising" are open-ended, i.e., a system, apparatus, article, composition, or process that comprises elements other than those listed after such term in a claim are still considered to be within the scope of that 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 capability, a web tablet, a wireless telephone, a smart phone, a wireless headset, a pager, an instant messaging device, a digital camera, an access point, a television, a medical device (e.g., a heart rate monitor, a blood pressure monitor, etc.), a wearable device, or other device that may receive and/or transmit information wirelessly. 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, speakers, and other mobile device elements. 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 transmission of RF signals. In some multiple-input multiple-output (MIMO) embodiments, the antennas may be equally spaced to take advantage of spatial diversity and the different channel characteristics that may be obtained.

One or more of the functional elements of a UE or eNB may be combined and may be implemented by combinations of software-configured elements, such as processing elements including Digital Signal Processors (DSPs), and/or other hardware elements. For example, some elements may comprise 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 circuitry 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.

Embodiments may be implemented in one or a combination of hardware, firmware, and software. 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-transitory mechanism that stores information in a form readable by a machine (e.g., a computer). For example, a computer-readable storage medium may include Read Only Memory (ROM), Random Access Memory (RAM), magnetic disk storage media, optical storage media, flash memory devices, and other storage devices and media. In these embodiments, one or more processors may be configured with instructions to perform the operations described herein.

In some embodiments, a UE or eNB (fig. 1) may be configured to: orthogonal Frequency Division Multiplexed (OFDM) communication signals are transmitted and/or received over a multicarrier communication channel in accordance with an Orthogonal Frequency Division Multiple Access (OFDMA) technique. The OFDM signal may include a plurality of orthogonal subcarriers. In some wideband multicarrier embodiments, the UE and eNB may be part of a cellular wideband wireless access (BWA) network communication network, such as a third generation partnership project (3GPP) Universal Terrestrial Radio Access Network (UTRAN) Long Term Evolution (LTE) or Long Term Evolution (LTE) communication network, although the scope of the invention is not limited in this respect.

In some embodiments, a 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 modulated code division multiple access (FH-CDMA)), Time Division Multiplexing (TDM) modulation, and/or Frequency Division Multiplexing (FDM) modulation, although the scope of the embodiments is not limited in this respect.

The above description is intended to be illustrative, and not restrictive. For example, the above-described examples (or one or more aspects thereof) may be used in combination with other examples. Other embodiments may be used, for example, by one skilled in the art after reading the above description. The abstract is intended to allow the reader to quickly ascertain the nature of the technical disclosure, for example, to comply with federal state 37c.f.r. section 1.72 (b). It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing detailed description, various features may be combined together to streamline the disclosure. However, the claims may not recite each feature disclosed herein, as embodiments may have a subset of the features recited. Moreover, embodiments may include fewer features than are disclosed in a particular example. Thus the following claims are hereby incorporated into the detailed description, with one claim standing on its own as a separate embodiment. The scope of the embodiments disclosed herein will be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims (20)

1. A UE (user equipment) comprising:

a wireless transceiver for communicating with an eNB (evolved node B);

a processing circuit to:

demodulating a PDSCH (physical data shared channel) received from the eNB;

calculating a Channel Quality Indication (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.

2. The UE of claim 1, wherein the processing circuitry is to modify the CQI based on interference estimation performed during PDSCH demodulation by:

the interference contributing channels are estimated from reference signals present in the PDSCH allocation and the interfering signal parameters within the PDSCH are estimated by using higher layer signaling from neighboring cells related to the parameters of the interfering signals to assist and scan possible parameters to determine the parameters that are most likely to have been received.

3. The UE of claim 1, wherein the processing circuitry is to configure the transceiver to: transmitting a CSI (channel State information) report including the modified CQI to the eNB.

4. The UE of claim 1, wherein the processing circuitry is to configure the transceiver to: transmitting a CSI report containing a modified CQI to the eNB if CSI (channel State information) reference resources defined by the eNB completely overlap with resource allocation of a PDSCH in time and frequency.

5. The UE of claim 4, wherein the processing circuitry is to configure the transceiver to: transmitting 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 PDSCH.

6. The UE of claim 1, wherein the processing circuitry is to configure the transceiver to: transmitting a CSI report including the modified CQI to the eNB in a case where a CSI (channel State information) reference resource definition is extended to include a resource allocation of the PDSCH.

7. The UE of claim 6, wherein, if there is no scheduled PDSCH on a CSI reference resource, the processing circuitry is to configure the transceiver to: transmitting a CSI report to the eNB that does not include the modified CQI.

8. The UE of claim 1, wherein the processing circuitry is to configure the transceiver to: transmitting a CSI report including a modified CQI to the eNB, in case a CSI (channel State information) reference resource definition is limited to a resource allocation of a PDSCH.

9. The UE of claim 1, wherein the processing circuitry is to configure the transceiver to: transmitting a CSI report containing a modified CQI to the eNB in case that a CSI (channel State information) reference resource definition is extended to a resource allocation of a PDSCH, wherein the CSI report contains the modified CQI as a delta MCS (modulation coding scheme) indicating a difference between an actually allocated MCS and a highest MCS estimated at the UE satisfying a target BLER (Block error Rate).

10. A method of operating a UE (user equipment), comprising:

demodulating a PDSCH (physical data shared channel) received from an eNB;

calculating a Channel Quality Indication (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.

11. The method of claim 10, further comprising: modifying the CQI based on interference estimation performed during PDSCH demodulation by:

the interference contributing channels are estimated from reference signals present in the PDSCH allocation and the interfering signal parameters within the PDSCH are estimated by using higher layer signaling from neighboring cells related to the parameters of the interfering signals to assist and scan possible parameters to determine the parameters that are most likely to have been received.

12. The method of claim 10, further comprising: transmitting a CSI (channel State information) report including the modified CQI to the eNB.

13. The method of claim 10, further comprising: transmitting a CSI report containing a modified CQI to the eNB if CSI (channel State information) reference resources defined by the eNB completely overlap with resource allocation of a PDSCH in time and frequency.

14. The method of claim 13, further comprising: transmitting 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 PDSCH.

15. The method of claim 10, further comprising: transmitting a CSI report including the modified CQI to the eNB in a case where a CSI (channel State information) reference resource definition is extended to include a resource allocation of the PDSCH.

16. The method of claim 15, further comprising: transmitting a CSI report without modified CQI to the eNB if there is no scheduled PDSCH on a CSI reference resource.

17. The method of claim 10, further comprising: transmitting a CSI report including a modified CQI to the eNB, in case a CSI (channel State information) reference resource definition is limited to a resource allocation of a PDSCH.

18. The method of claim 10, further comprising: transmitting a CSI report containing a modified CQI to the eNB in case that a CSI (channel State information) reference resource definition is extended to a resource allocation of a PDSCH, wherein the CSI report contains the modified CQI as a delta MCS (modulation coding scheme) indicating a difference between an actually allocated MCS and a highest MCS estimated at the UE satisfying a target BLER (Block error Rate).

19. A non-transitory computer-readable storage medium that stores instructions for execution by one or more processors of a user equipment to perform operations that configure a UE to:

estimating interference during demodulation of a PDSCH (physical data shared channel) received from an eNB using Network Assisted Interference Cancellation and Suppression (NAICS) higher layer signaling assistance from neighboring cells; and

calculating a Channel Quality Indication (CQI) based on a reference signal received from the eNB, wherein the CQI is modified according to the estimated interference.

20. The medium of claim 19, further comprising stored instructions to: modifying the CQI based on interference estimation performed during PDSCH demodulation by:

the interference contributing channels are estimated from reference signals present in the PDSCH allocation and the interfering signal parameters within the PDSCH are estimated by scanning the possible parameters to determine the parameters that are most likely to have been received.