WO2019019174A1

WO2019019174A1 - Method and apparatus for high-order table configuration

Info

Publication number: WO2019019174A1
Application number: PCT/CN2017/094968
Authority: WO
Inventors: Yu Xin; Luanjian BIAN; Jun Xu
Original assignee: Zte Corporation
Priority date: 2017-07-28
Filing date: 2017-07-28
Publication date: 2019-01-31

Abstract

A method and apparatus for supporting higher order modulation schemes for communication systems is disclosed. In one embodiment, a method performed by a first communication node includes : transmitting a reference signal to a second communication node; receiving a channel quality indicator (CQI) signal from the second communication node； based on at least the CQI signal, determining a maximum modulation order for future signal transmissions to the second communication node; based on the determined maximum modulation order, determining a table configuration from among at least three predefined table configurations， wherein a first predefined table supports a first maximum modulation order, a second predefined table configuration supports a second maximum modulation order greater than the first maximum modulation order, and a third predefined table configuration supports a third maximum modulation order greater than the second maximum modulation order.

Description

METHOD AND APPARATUS FOR HIGH-ORDER TABLE CONFIGURATION

TECHNICAL FIELD

This disclosure relates generally to wireless communications and, more particularly, to a method and apparatus for high-order table configuration.

BACKGROUND

With the continuous development of wireless communication technologies, a wide range of wireless communication services are emerging, which will greatly increase the demand for bandwidth in wireless communication systems. Thus, the traditional frequency range of 300 MegaHertz (MHz) and 3 GigaHertz (GHz) for commercial communication systems must be utilized efficiently in order to meet the market demand for future wireless communication services.

In the future 5G wireless communication system, a.k.a., New Radio (NR) , the carrier frequency can be higher than that in traditional wireless communication systems. For example, it is contemplated that the NR communication system may operate at frequencies of 28 GHz, 45 GHz, and up to 100 GHz to deliver high data rates with higher bandwidths. In addition to the higher operating frequencies and wider channel bandwidths, a higher spectrum efficiency in 5G NR may be achieved through the use of higher-order modulation schemes (e.g., 1024 QAM) . Thus, more sophisticated signal structures, as well as other technologies, e.g., multiple-input-multiple-output (MIMO) technologies, will be increasingly utilized in the NR communication systems and protocols.

Quadrature amplitude modulation or “QAM” is a form of modulation, which is widely used for modulating data signals onto a carrier used for wireless communications. When using QAM, constellation points are normally arranged in a square grid with equal vertical and horizontal spacing and as a result, the most common forms of QAM use a constellation with the number of points equal to 2^M, where M is the modulation order. For example, there are 16, 64, and 256 constellation points, when M equals to 2, 4 and 6, which correspond to 16 QAM, 64 QAM, and 256 QAM, respectively.

QAM is widely used because it offers advantages over other forms of data modulation such as PSK (Phase-Shift Keying) . The advantage of moving to a higher order QAM (e.g., 256 QAM or above) is that there are more points within the constellation and therefore it more efficiently transmits more bits per symbol resulting in a higher bandwidth efficiency. For example, increasing from 16 QAM to 256 QAM, the constellation points increases from 16 to 256 points and the theoretical bandwidth efficiency increases from 4 to 8.

The downside is that the constellation points are closer together and therefore the link is more susceptible to noise. As a result, higher-order QAM are only used where there is a sufficiently high signal to noise ratio. In general, when a user equipment (hereinafter “UE” ) is close to the base station (hereinafter “BS” ) , a strong direct line of sight is available, when the UE is fixed or moves with small velocities, especially within a very small-cell BS area, e.g., home base station, and under excellent environmental conditions.

The LTE (Long Term Evolution) system has experienced several specification revisions as measured by “Release” from Release 8 to 14 (R8-R14) by 3GPP (3^rd Generation Partnership Project) . In the latest Release (R14) , uplink and downlink transmission in the current LTE system only support up to 256 QAM. With the continuous evolution of LTE, it is necessary to introduce a higher-order modulation, e.g., 1024 QAM, in situations mentioned above for improved overall network capacity and bandwidth efficiency. However, existing standards in the specifications do not support this high-order modulation. For example, the existing LTE standard mapping tables including Channel Quality Indicator (CQI) tables and Modulation Coding Scheme (MCS) tables only support up to 256 QAM and a bandwidth efficiency of up to 7.4 bps/Hz.

Thus, there exists a need to develop new enhanced tables to support higher-order modulation schemes (above 256 QAM) . The present invention provides a method and apparatus for selecting and applying a table configuration containing at least one CQI table and one MCS table that are compatible with current communication systems and can support scenarios where a higher-order modulation (e.g., 1024 QAM) can be utilized.

SUMMARY OF THE INVENTION

The exemplary embodiments disclosed herein are directed to solving the issues related to one or more of the problems presented in the prior art, as well as providing additional features that will become readily apparent by reference to the following detailed description when taken in conjunction with the accompany drawings. In accordance with various embodiments, exemplary systems, methods, and computer program products are disclosed herein. It is understood, however, that these embodiments are presented by way of example and not limitation, and it will be apparent to those of ordinary skill in the art who read the present disclosure that various modifications to the disclosed embodiments can be made while remaining within the scope of the invention.

In one embodiment, a method includes: transmitting a reference signal to a second communication node； receiving a channel quality indicator (CQI) signal from the second communication node； based on at least the CQI signal, determining a maximum modulation order for future signal transmissions to the second communication node； based on the determined maximum modulation order, determining a table configuration from among at least three predefined table configurations, wherein a first predefined table supports a first maximum modulation order, a second predefined table configuration supports a second maximum modulation order greater than the first maximum modulation order, and a third predefined table configuration supports a third maximum modulation order greater than the second maximum modulation order.

In a further embodiment, a method includes: receiving a reference signal from a second communication node； performing channel quality measurements on the received reference signal to generate a channel quality indicator (CQI) signal； transmitting the CQI signal to the second communication node； and receiving information identifying a table configuration from the second communication node, wherein the table configuration is determined based on at least the CQI signal and comprises one of at least three predefined table configurations, wherein a first predefined table supports a first maximum modulation order, a second predefined table configuration supports a second maximum modulation order greater than the first maximum modulation order, and a third predefined table configuration supports a third maximum modulation order greater than the second maximum modulation order.

In another embodiment, a first communication node includes: a transceiver configured to transmit a reference signal to a second communication node, and receive a channel quality indicator (CQI) signal from the second communication node； and at least one processor configured to: based on at least the CQI signal, determine a maximum modulation order for future signal transmissions to the second communication node； and based on the determined maximum modulation order, determine a table configuration from among at least three predefined table configurations, wherein a first predefined table supports a first maximum modulation order, a second predefined table configuration supports a second maximum modulation order greater than the first maximum modulation order, and a third predefined table configuration supports a third maximum modulation order greater than the second maximum modulation order.

In yet another embodiment, a first communication node includes: a transceiver configured to receive a reference signal from a second communication node； and at least one processor configured to perform channel quality measurements on the received reference signal to generate a channel quality indicator (CQI) signal, wherein the transceiver is further configured to: transmit the CQI signal to the second communication node； and receive information identifying a table configuration from the second communication node, wherein the table configuration is determined based on at least the CQI signal and comprises one of at least three predefined table configurations, wherein a first predefined table supports a first maximum modulation order, a second predefined table configuration supports a second maximum modulation order greater than the first maximum modulation order, and a third predefined table configuration supports a third maximum modulation order greater than the second maximum modulation order.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the following detailed description when read with the accompanying figures. It is noted that various features are not necessarily drawn to scale. In fact, the dimensions and geometries of the various features may be arbitrarily increased or reduced for clarity of discussion.

FIG. 1A illustrates an exemplary wireless communication network illustrating achievable maximum orders of modulation as a function of distance between a UE and a BS, in accordance with an embodiment of the present disclosure.

FIG. 1B illustrates a block diagram of an exemplary wireless communication system for transmitting and receiving higher-order modulation wireless communication signals, in accordance with some embodiments of the present disclosure.

FIG. 2A illustrates an exemplary 64 QAM CQI table with 16 entries, in accordance with some embodiments of the present disclosure.

FIG. 2B illustrates an exemplary 256 QAM CQI table with 16 entries, in accordance with some embodiments of the present disclosure.

FIG. 2C illustrates an exemplary 1024 QAM CQI table with 16 entries, in accordance with some embodiments of the present disclosure.

FIG. 3A illustrates an exemplary 64 QAM MCS table with 32 entries, in accordance with some embodiments of the present disclosure.

FIG. 3B illustrates an exemplary 256 QAM MCS table with 32 entries, in accordance with some embodiments of the present disclosure.

FIG. 3C illustrates an exemplary 1024 QAM MCS table with 32 entries, in accordance with some embodiments of the present disclosure.

FIG. 4A illustrates a flow chart of a method to determine a table configuration, in accordance with some embodiments of the present disclosure.

FIG. 4B illustrates a flow chart of a method to determine a table configuration, in accordance with some embodiments of the present disclosure.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Various exemplary embodiments of the invention are described below with reference to the accompanying figures to enable a person of ordinary skill in the art to make and use the invention. As would be apparent to those of ordinary skill in the art, after reading the present disclosure, various changes or modifications to the examples described herein can be made without departing from the scope of the invention. Thus, the present invention is not limited to the exemplary embodiments and applications described or illustrated herein. Additionally, the specific order or hierarchy of steps in the methods disclosed herein are merely exemplary approaches. Based upon design preferences, the specific order or hierarchy of steps of the disclosed methods or processes can be re-arranged while remaining within the scope of the present invention. Thus, those of ordinary skill in the art will understand that the methods and techniques disclosed herein present various steps or acts in a sample order, and the invention is not limited to the specific order or hierarchy presented unless expressly stated otherwise.

Embodiments of the present invention are described in detail with reference to the accompanying drawings. The same or similar components may be designated by the same or similar reference numerals although they are illustrated in different drawings. Detailed descriptions of constructions or processes well-known in the art may be omitted to avoid obscuring the subject matter of the present invention. Further, the terms are defined in consideration of their functionality in embodiment of the present invention, and may vary according to the intention of a user or an operator, usage, etc. Therefore, the definition should be made on the basis of the overall content of the present specification.

In accordance with various embodiments, CQI tables and MCS tables are redesigned in order to support higher-order modulation schemes (e.g., 1024 QAM) for use in a 5G NR system. In particular, the CQI and MCS tables in a new table configuration for higher-order modulation can be obtained by modifying existing tables so that the maximum modulation order can be increased without requiring any extra signaling bits in the downlink control information (DCI) or uplink control information (UCI) formats, or modification to the existing infrastructure. In this disclosure, the term higher-order modulation may refer to modulation schemes that are higher than 256 QAM, such as 1024 QAM, which allows a theoretical bandwidth efficiency of 10 bits per symbol.

Figure 1A illustrates an exemplary wireless communication network 100 illustrating achievable modulation as a function of distance from a BS 102, in accordance with some embodiments of the present disclosure. In a wireless communication system, a network side communication node or a base station (BS) can be a node B, an E-utran Node B (also known as Evolved Node B, eNodeB or eNB) , a pico station, a femto station, or the like. A terminal side node or a user equipment (UE) can be a long range communication system like a mobile phone, a smart phone, a personal digital assistant (PDA) , tablet, laptop computer, or a short range communication system such as, for example a wearable device, a vehicle with a vehicular communication system and the like. A network and a terminal side communication node are represented by a BS 102 and a UE 104, respectively, and in all the embodiments in this disclosure hereafter, and are generally referred to has “communication nodes” herein. Such communication nodes may be capable of wireless and/or wired communications, in accordance with various embodiments of the invention. It is noted that all the embodiments are merely preferred examples, and are not intended to limit the present disclosure. Accordingly, it is understood that the system may include any desired combination of UEs and BSs, while remaining within the scope of the present disclosure.

Referring to Figure 1A, the wireless communication network 100 includes a BS 102 and a UE 104 which moves in a cell 110 or coverage area established by the BS 102, wherein each position of the UE 104 from 104a to 104b to 104c to 104d to 104e represents the UE 104 moving from an edge of the cell 110 towards the BS 102, respectively.

A wireless transmission from a transmitting antenna of the UE 104 to a receiving antenna of the BS 102 is known as an uplink transmission, and a wireless transmission from a transmitting antenna of the BS 102 to a receiving antenna of the UE 104 is known as a downlink transmission. The BS 102 and the UE 104 are contained within a geographic boundary of cell 110.

When the UE 104 is at the extreme cell edge 110, e.g., at 104a with a longer distance between the BS 102 and UE 104a, path loss becomes significant, so the UE 104 will transmit at a maximum power over a long distance and most importantly with the most robust modulation (QPSK, Quadrature Phase Shifting Keying) . As a result, the data rate is relatively low between BS 102 and UE 104a in this case.

As the UE 104 moves closer to the BS 102, the path loss decreases and the signal level at the BS 102 increases, thus the SNR improves. In response, the BS 102 instructs the UE 104 to reduce power to minimize interference to other UE’s and/or the BS 102. However, as soon as the SNR level passes a threshold and supports a higher-order modulation, the BS 102 will instruct the UE 104 to switch modulations in order to improve overall network capacity and bandwidth efficiency. For example, the BS 102 instructs the UE 104 at position 104b to switch from QPSK to 16 QAM and further switch to 64 QAM, 256 QAM and 1024 QAM when the UE 104 moves to

positions

104c, 104d and 104e, respectively, each having improved channel quality compared to the previous positions.

Figure 1B illustrates a block diagram of an exemplary wireless communication system 150 for transmitting and receiving higher-order modulation wireless communication signals, in accordance with some embodiments of the present disclosure. The system 150 may include components and elements configured to support known or conventional operating features that need not be described in detail herein. In one exemplary embodiment, system 150 can be used to transmit and receive data symbols in a wireless communication environment such as the wireless communication network 100 of Figure 1A, as described above.

System 150 generally includes a base station 102 and a UE 104. The base station 102 includes a BS transceiver module 152, a BS antenna 154, a BS memory module 156, a BS processor module 158, and a network communication module 160, each module being coupled and interconnected with one another as necessary via a data communication bus 180. The UE 104 includes a UE transceiver module 162, a UE antenna 164, a UE memory module 166, and a UE processor module 168, each module being coupled and interconnected with one another as necessary via a date communication bus 190. The BS 102 communicates with the UE 104 via a communication channel 192, which can be any wireless channel or other medium known in the art suitable for transmission of data as described herein.

As would be understood by persons of ordinary skill in the art, system 150 may further include any number of modules other than the modules shown in Figure 1A. Those skilled in the art will understand that the various illustrative blocks, modules, circuits, and processing logic described in connection with the embodiments disclosed herein may be implemented in hardware, computer-readable software, firmware, or any practical combination thereof. To clearly illustrate this interchangeability and compatibility of hardware, firmware, and software, various illustrative components, blocks, modules, circuits, and steps are described generally in terms of their functionality. Whether such functionality is implemented as hardware, firmware, or software depends upon the particular application and design constraints imposed on the overall system. Those familiar with the concepts described herein may implement such functionality in a suitable manner for each particular application, but such implementation decisions should not be interpreted as limiting the scope of the present invention.

In accordance with some embodiments, a UE transceiver 162 may be referred to herein as an "uplink" transceiver 162 that includes a RF transmitter and receiver circuitry that are each coupled to the antenna 164. A duplex switch (not shown) may alternatively couple the uplink transmitter or receiver to the uplink antenna in time duplex fashion. Similarly, in accordance with some embodiments, the BS transceiver 152 may be referred to herein as a "downlink" transceiver 152 that includes RF transmitter and receiver circuitry that are each coupled to the antenna 154. A downlink duplex switch may alternatively couple the downlink transmitter or receiver to the downlink antenna 154 in time duplex fashion. The operations of the two

transceivers

152 and 162 are coordinated in time such that the uplink receiver is coupled to the uplink antenna 164 for reception of transmissions over the wireless communication channel 192 at the same time that the downlink transmitter is coupled to the downlink antenna 154. Preferably, there is close time synchronization with only a minimal guard time between changes in duplex direction.

The UE transceiver 162 and the BS transceiver 152 are configured to communicate via the wireless data communication link 192, and cooperate with a suitably configured RF antenna arrangement 154/164 that can support a particular wireless communication protocol and modulation scheme. In some exemplary embodiments, the UE transceiver 162 and the BS transceiver 152 are configured to support industry standards such as the Long Term Evolution (LTE) and emerging 5G standards, and the like. It is understood, however, that the invention is not necessarily limited in application to a particular standard and associated protocols. Rather, the UE transceiver 162 and the BS transceiver 152 may be configured to support alternate, or additional, wireless data communication protocols, including future standards or variations thereof.

The

processor modules

158 and 168 may be implemented, or realized, with a general purpose processor, a content addressable memory, a digital signal processor, an application specific integrated circuit, a field programmable gate array, any suitable programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions described herein. In this manner, a processor may be realized as a microprocessor, a controller, a microcontroller, a state machine, or the like. A processor may also be implemented as a combination of computing devices, e.g., a combination of a digital signal processor and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a digital signal processor core, or any other such configuration.

Furthermore, the steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, in firmware, in a software module executed by

processor modules

158 and 168, respectively, or in any practical combination thereof. The

memory modules

156 and 166 may be realized as RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. In this regard, the

memory modules

156 and 166 may be coupled to the

processor modules

158 and 168, respectively, such that the

processors modules

158 and 168 can read information from, and write information to,

memory modules

156 and 166, respectively. The

memory modules

156 and 166 may also be integrated into their

respective processor modules

158 and 168. In some embodiments, the

memory modules

156 and 166 may each include a cache memory for storing temporary variables or other intermediate information during execution of instructions to be executed by

processor modules

158 and 168, respectively.

Memory modules

156 and 166 may also each include non-volatile memory for storing instructions to be executed by the

processor modules

158 and 168, respectively.

The network communication module 160 generally represents the hardware, software, firmware, processing logic, and/or other components of the base station 102 that enable bi-directional communication between BS transceiver 152 and other network components and communication nodes configured to communication with the BS 102. For example, network communication module 160 may be configured to support internet or WiMAX traffic. In a typical deployment, without limitation, network communication module 160 provides an 802.3 Ethernet interface such that BS transceiver 152 can communicate with a conventional Ethernet based computer network. In this manner, the network communication module 160 may include a physical interface for connection to the computer network (e.g., Mobile Switching Center (MSC) ) . The terms “configured for” or “configured to” as used herein with respect to a specified operation or function refers to a device, component, circuit, structure, machine, signal, etc. that is physically constructed, programmed, formatted and/or arranged to perform the specified operation or function

Referring again to Figure 1A, as mentioned above, the BS 102 repeatedly broadcasts system information associated with the BS 102 to one or more UEs (e.g., 104) so as to allow the UE 104 to access the network within the cell 110 where the BS 102 is located, and in general, to operate properly within the cell 110. Plural information such as, for example, downlink and uplink cell bandwidths, downlink and uplink configuration, configuration for random access, etc., can be included in the system information, which will be discussed in further detail below. Typically, the BS 102 broadcasts a first signal carrying some major system information, for example, configuration of the cell 110 through a PBCH (Physical Broadcast Channel) . For purposes of clarity of illustration, such a broadcasted first signal is herein referred to as “first broadcast signal. ” It is noted that the BS 102 may subsequently broadcast one or more signals carrying some other system information through respective channels (e.g., a Physical Downlink Shared Channel (PDSCH) ) , which are herein referred to as “second broadcast signal, ” “third broadcast signal, ” and so on.

Referring again to Figure 1B, in some embodiments, the major system information carried by the first broadcast signal may be transmitted by the BS 102 in a symbol format via the communication channel 192 (e.g., a PBCH) . In accordance with some embodiments, an original form of the major system information may be presented as one or more sequences of digital bits and the one or more sequences of digital bits may be processed through plural steps (e.g., coding, scrambling, modulation, mapping steps, etc. ) , all of which can be processed by the BS processor module 158, to become the first broadcast signal. Similarly, when the UE 104 receives the first broadcast signal (in the symbol format) using the UE transceiver 162, in accordance with some embodiments, the UE processor module 168 may perform plural steps (de-mapping, demodulation, decoding steps, etc. ) to estimate the major system information such as, for example, bit locations, bit numbers, etc., of the bits of the major system information.

Figures 2A-2C illustrate three exemplary CQI tables including a 64 QAM CQI table, a 256 QAM CQI table and a 1024 QAM CQI table, each with 16 entries or index values, in accordance with some embodiments. Since each table contains only 16 possible index values (0 to 15) , only four bits are required to specify each index value. Based on a CQI report received by the BS 102 from the UE 104, which will be discussed in further detail below with respect to Figures 4A and 4B, and further based on detection of a higher possible modulation order compared to a maximum modulation order of a default CQI table (e.g., a 64 QAM CQI table as shown in Figure 2A) , the BS 102 instructs the UE 104 to use a second or a third CQI table configuration that supports the detected higher modulation order. The second CQI table (e.g., the 256 QAM table as shown in Figure 2B) and the third CQI table (e.g., the 1024 QAM table as shown in Figure 2C) each include at least one entry that can support a higher-order modulation compared to the maximum modulation order of the default CQI table. For example, as shown in Figure 2A, the 64 QAM CQI table contains 6 entries for QPSK modulation, 3 entries for 16 QAM modulation and 6 entries for 64 QAM modulation. Referring to Figure 2A, as an example, it is noted that at different code rates 203, different bandwidth efficiencies 204 can be achieved for the same modulation orders 202. For example, 6 entries for the maximum modulation order 64 QAM have different bandwidth efficiencies 204 which increases with increasing code rates 203.

Referring to Figure 2B, for a 256 QAM CQI table, at least one entry for each modulation order from the 64 QAM CQI table (Fig. 2A) is maintained, at least one entry at each lower modulation order (e.g., QPSK, 16 QAM and 64 QAM) is deleted, and at least one entry at a higher modulation order (e.g., 256 QAM) is added. For example, entry 1 with a CQI index of 1 in Figure 2A is maintained in the first entry with a CQI index 1 in Figure 2B. In Figure 2B, there are 3 entries for QPSK modulation, 3 entries for 16 QAM modulation, 5 entries for 64 QAM modulation, and 4 entries for 256 QAM modulation. It should be noted that the example 256 QAM table shown in Figure 2B is merely an example, different number of entries for each modulation order 202 at different code rates 203 thus with different bandwidth efficiencies 204 can be constructed in accordance with various embodiments of the invention.

As shown in Figure 2C, a CQI table for 1024 QAM can be obtained by modifying the current 256 QAM CQI tables used in LTE. For example, as shown in Figure 2C, 2 new entries for 1024 QAM modulation are added to the CQI table as shown Figure 2B, 2 entries for QPSK modulation (

CQI index

1 and 2 in Figure 2B) are removed and 1 entry for 256 QAM modulation is modified with a different code rate (CQI index 15 in Figure 2B) . In this invention, at least one new CQI table that supports higher-order modulation (e.g., 1024 QAM or above) is added while two CQI tables that supports lower-order modulation (256 QAM or lower) are maintained. Thus, when the radio condition gets better or worse or when switching transmission mode (e.g., downlink to uplink or vice versa) , there is at least one table with at least one entry with an optimum modulation order that can be applied to maximize bandwidth efficiency and data rates while maintaining sufficiently low error rates.

Figures 3A-3C illustrate three exemplary MCS tables including a 64 QAM MCS table, a 256 QAM MCS table and a 1024 QAM MCS table with 32 entries or index values, in accordance with some embodiments. Since each table contains only 32 possible index values (0 to 31) , only five bits are required to specify each index value. As further discussed below, based at least on a CQI report received from the UE 104, the BS 102 further selects a corresponding MCS table for the UE 104. As discussed above, when a higher modulation is detected which is higher than the maximum modulation order of a default CQI table (e.g., the 64 QAM CQI table of Figure 2A) , the BS 102 instructs the UE 104 to use a second or a third CQI table that supports a higher-order modulation order. In corresponding fashion, the BS 102 can also select a second or a third MCS table that also supports the higher-order modulation scheme for the UE 104, in accordance with some embodiments.

Figures 3A and 3B show two MCS tables which support modulation order up to 64 QAM and 256 QAM, respectively, in the current LTE specifications. Similar to the additional CQI table of Figure 2C, the additional MCS table of Figure 3C supports a modulation order higher than 256 QAM without increasing the number of bits in the DCI/UCI formats or the number of entries/index values in the MCS table that are required to be uniquely specified. In some embodiments, the MCS tables are generated based on computer simulation results as would be understood by persons skilled in the art. In the exemplary new MCS table shown in Figure 3C, three new entries for 1024 QAM higher-order modulation are added. It should be noted that the invention is not limited to the specific examples of MCS/CQI tables described herein and that any MCS/CQI tables may be configured or used, in accordance with various embodiments of the invention.

In accordance with some embodiments, the two exemplary new CQI and MCS tables shown in Figures 2C and 3C, respectively, can be added to existing CQI and MCS tables to provide new possible table configurations to support higher-order modulation (e.g., 1024 QAM) to improve overall network capacity and bandwidth efficiency, in the scenarios discussed above. Such scenarios include, for example, when there is a high SNR in a current channel, the UE 104 (e.g., 104e in Figure 1A) is close to the BS 102, a strong direct line of sight between the UE 104 and the BS 102, when the UE 104 is fixed or moves with small velocities, especially within a very small-cell BS area, e.g., home base station, and under excellent environmental conditions.

Figure 4A illustrates a method 400 of selecting a CQI table and/or a MCS table for the UE 104 when the BS 102 does not configure CSI (Channel State Information) measurement subframe sets for the UE 104, according to some embodiments of the present disclosure. It is understood that additional operations may be provided before, during, and after the method 400 of Figure 4, and that some other operations may be omitted or only briefly described herein.

The method 400 starts with operation 401, where the BS 102 transmits a downlink reference signal (DLRS) to the UE 104. In some embodiments, using a beam sweeping technique, for example, a plurality of DLRSs are transmitted from the BS 102 to the UE 104 using the respective transmitting beams of the BS 102 and receiving beams of the UE 104. In some embodiments, the DLRS from the BS 102 can be a Sound Reference Signals (SRS) , or transmitted on channels such as, for example, a Physical Random Access Channel (PRACH) , a Physical Downlink Control Channel (PDCCH) , and a Physical Downlink Shared Channel (PDSCH) .

In some embodiments, the DLRSs are staggered in time and frequency, which allows the UE 104 to perform complex interpolation of channel time-frequency response to estimate the channel effect on the transmitted information. In some embodiments, a DLRS can also be a Cell-specific reference signal (CSRS) or a UE-specific reference signal (UESRS) .

The method 400 continues with operation 402, during which CQI values are measured and estimated by the UE 104 based on the DLRS from the BS 102, which are affected by the following factors such as, for example, signal-to-noise ratio (SNR) , signal-to-interference plus noise ratio (SINR) , signal-to-noise plus distortion ratio (SNDR) and the like. In some embodiments, SNR is a significant criterion for the UE 104 to determine the CQI index with the exact mapping relation between the SNR and CQI index varying a little depending on other factors. In some embodiments, the SNR often expressed in decibels (dB) has a linear relationship with the CQI index.

The method continues with operation 403, in which, after the UE 104 determines the CQI value, a corresponding CQI index between 0 and 15 is derived based on a default 4 QAMCQI table (e.g., the exemplary 64 QAM CQI table shown in Figure 2A) in accordance with techniques understood by persons skilled in the art. In some embodiments, the predefined 64 QAM CQI table is configured and informed by the BS 102 to the UE 104 by a higher layer signal (e.g., RRC message) above the physical layer. Then, the derived CQI index is transmitted back to the BS 102 through CQI reporting, which is typically carried on Physical Uplink Control Channel (PUCCH) and/or Physical Uplink Shared Channel (PUSCH) . The time and frequency resources that can be used by the UE 104 to report CQI are controlled by the BS 102. In some embodiments, a CQI reporting can be conducted either periodically on a PUCCH or a PUSCH with a period preconfigured by the higher layer, or triggered by the BS 102 on PUSCH either upon receiving a DCI format 0 or a Random Access Response Grant. In some embodiments, the CQI reporting can be a 4-bit wide-band CQI, 2-bit differential sub-band CQI, or a 3-bit differential Spatial CQI.

The method 400 continues with operation 404, in which the BS 102, selects a CQI table supporting a maximum modulation order based on the CQI report received from the UE 104 and other possible factors such as collection conditions, retransmission times, etc. Depending at least on the CQI report, the selected CQI table may be the same or different from the default 4 QAMCQI table. In accordance various embodiments, at least three CQI tables are available for selection, with at least one of the CQI tables supporting 1024 QAM or a higher order modulation scheme.

The method 400 continues with operation 405, in which the new CQI table and the CQI index determined by the BS 102 are transmitted back to the UE 104 through a higher layer signal (RRC message) . At the same time, the method 400 continues with operation 406, where the BS 102 selects a MCS table with a corresponding maximum modulation order based on the maximum modulation order of the new CQI table and the new CQI value.

In some embodiments, the BS 102 select one MCS table for the UE 104 based on the CQI information from the UE 104 by selecting one of three available MCS tables with respective maximum modulation orders of M-2, M, and M+2, where M＝6. A MCS table with the maximum modulation order of 4, 6 and 8 corresponds to a 64 QAM MCS table, a 256 QAM MCS table and a 1024 QAM MCS table, respectively. In some embodiments, if the selected CQI table has a maximum modulation order of M＝6 (256 QAM) , for example, the BS 102 also assigns a MCS table with the maximum modulation order M of 6 (256 QAM) to the UE 104. Similarly, if the selected CQI table has a maximum modulation order M of 8 (1024 QAM) , the BS 102 also assigns a MCS table with the maximum modulation order M of 8 (1024 QAM) to the UE 104.

Further, the number of resource blocks and MCS for each CQI value are then determined by the BS 102 to properly allocate the resource for the UE 104. Based on the CQI value, a range of MCS index values in a corresponding MCS table is then selected by the BS 102. A specific MCS index value and number of resource blocks can then be determined together with the code rate 203 shown in the corresponding CQI table based on a corresponding transport block size (TBS) table, as known in the art.

The method 400 continues with operation 407, in which depending on the CQI index, the BS 102 transmits scheduling information back to the UE 104 including allocated resources, transport block size for data transmission, modulation and coding scheme, and the like. In some embodiments, if the BS 102 receives a CQI index with a relatively large CQI value from the UE 104, the BS 102 transmit the data with a larger transport block size. Conversely, if the BS 102 receives a CQI index with a relatively small CQI value from the UE 104, the BS 102 transmits the data with a smaller transport block size.

In some embodiments, the BS 102 may select the maximum MCS (e.g., maximum code rate and largest transport block) for a downlink signal to the UE 104. If the UE 104 can successfully decode the signal, the UE 104 will send back the same or higher CQI value to the BS 102. Alternatively, if the UE 104 fails to successfully decode the signal, the UE 104 will send a CQI value that is less than the previous one. In response to receiving such a lower CQI value, the BS 102 transmits a signal with a lower MCS (e.g., lower code rate and smaller transport block) back to the UE 104. Thus, the BS 102 can dynamically adjust the MCS for the UE 104 to maximize the network capacity in accordance with real-time or dynamically changing conditions, in accordance with some embodiments.

Figure 4B illustrates a method 420 to select a CQI table and a MCS table for the UE 104 when the BS 102 configures CSI measurement subframe sets for the UE 104, in accordance with an embodiment of the present disclosure. It is understood that additional operations may be provided before, during, and after the method 420 of Figure 4B, and that some other operations may be omitted or only briefly described herein.

The method 420 starts with operation 421, in which the BS 102 transmits a higher layer message (e.g., a RRC message) specifying channel state information (CSI) measurement subframe sets, in accordance with some embodiments. In some embodiments, the measurement subframe sets comprises at least two subframe sets, a subframe set 0 (C_CSI, 0) and a subframe set 1 (C_CSI, 1) for CSI measurement. In some embodiments, the RRC message defines the location of the subframes as

CSI measurement subframes

0 and 1 in the time-frequency domain.

The method 420 continues with operation 422, where the BS 102 transmits a downlink reference signal (DLRS) to the UE 104. In some embodiments, using a beam sweeping technique, for example, the BS 102 transmits a plurality of DLRSs to the UE 104 using respective transmitting beams of the BS 102 and respective receiving beams of the UE 104. In some embodiments, the DLRSs are staggered in time and frequency, which allows the UE 104 to perform complex interpolation of channel time-frequency response to estimate the channel effect on the transmitted information. In some embodiments, a DLRS can be a Cell-specific reference signal (CSRS) or a UE-specific reference signal (UESRS) or transmitted on channels such as, for example, a Physical Random Access Channel (PRACH) , a Physical Uplink Control Channel (PUCCH) , and a Physical Uplink Shared Channel (PUSCH) .

The method 420 continues with operation 423, during which CQI and CSI values are measured at the dedicated two CSI measurement subframe sets and estimated by the UE 104 based on the DLRSs from the BS 102, which are affected by the following factors such as, for example, signal-to-noise ratio (SNR) , signal-to-interference plus noise ratio (SINR) , signal-to-noise plus distortion ratio (SNDR) and the like. In some embodiments, SNR is a significant criterion for the UE 104 to determine the CQI index with the exact mapping relation between the SNR and CQI index varying a little depending onother factors. In some embodiments, the SNR often expressed in decibels (dB) has a linear relationship with the CQI index. In some embodiments, the CSI measurement is based on reference signals including DL CIS-RS and or CRS.

The method 420 continues with operation 424, in which, after the UE 104 determines the CQI index value between 0-15 based on an exemplary default 4 QAMCQI table (e.g., the 64 QAM CQI table shown in Figure 2A) , the UE 104 sends a CQI report to the BS 102. In some embodiments, the 4 QAM default CQI table is configured by the BS 102 and then specified to the UE 104 by a higher layer signal (e.g., a RRC message) . In accordance with various embodiments, the CQI report is carried on a Physical Uplink Control Channel (PUCCH) and/or Physical Uplink Shared Channel (PUSCH) . The time-frequency resources that can be used by the UE 104 to report CQI are controlled by the BS 102. In some embodiments, a CQI report can be transmitted either periodically on PUCCH or PUSCH with a period preconfigured by the higher layer or triggered by the BS 102 on PUSCH either upon receiving a DCI format 0 or a Random Access Response Grant. In some embodiments, the CQI reporting can be a 4-bit wide-band CQI, 2-bit differential sub-band CQI, or a 3-bit differential Spatial CQI. In addition to the CQI index value, the UE 104 also returns CSI measurement results based on measurements on

subframes

0 and 1 together with the CQI reporting, in accordance with some embodiments.

The method 420 continues with operation 425, in which the BS 102 selects a CQI table that supports a maximum modulation order based on the CQI report and CSI measurement results received from the UE 104, along with other information such as collection conditions, retransmission times, etc. Depending at least on the CQI report and CSI measurement results, the selected CQI table may be the same or different from the default CQI table. In accordance various embodiments, at least three CQI tables are available for selection, with at least one of the CQI tables supporting 1024 QAM or a higher order modulation.

The method 420 continues with operation 426, in which the selected CQI table and the CQI index based on the selected CQI table, as determined by the BS 102, are transmitted back to the UE 104 through a higher layer signal (e.g., a RRC message) .

The method 420 continues with operation 427, where the BS 102 select a MCS table supporting a maximum modulation order corresponding to the maximum modulation order supported by the selected CQI tablebased on the CSI measurements for subframe sets 0 and 1. In some embodiments, the CSI measurement results are also transmitted in the CQI report. Specifically, when any one of the subframe sets 0 and 1 is configured with a CQI table with a maximum modulation order of M+2, a MCS table with a maximum modulation order of M+2 is selected for the UE 104 by the BS 102. All the subframes associated with the UE 104, including subframe sets 0 and 1, and other non-measurement subframes, are all configured with a MCS table with a maximum modulation order of M+2. Similarly, when the maximum modulation order of the CQI tables for any one of the CSI measurement subframe sets 0 and 1 is M, the BS 102 selects a MCS table with a maximum modulation order of M for the UE 104. When the maximum modulation order of the CQI tables for any one of the CSI measurement subframe set 0 and 1 is M-2, the BS 102 selects a MCS table with a maximum modulation order of M-2 for the UE 104. In some embodiments, M equals 6 which corresponds to a 256 QAM modulation, M-2 equals 4, which corresponds to 64 QAM and M+2 equals 8, which corresponds to 1024 QAM.

Further, the number of resource blocks and MCS for the CQI value are then determined by the BS 102 to properly allocate the resource for the UE 104. Based on the CQI value, a range of MCS in a corresponding MCS table is then selected by the BS 102. A specific MCS index value and number of resource blocks can then be determined together with the code rate 203 shown in the corresponding CQI table based on a corresponding transport block size (TBS) table, as known in the art. In some embodiments, when a modulation code scheme (MCS) table supporting a higher maximum modulation order (e.g., 1024 QAM) is selected for all CSI measurement subframe sets related to the UE 104, different CQI tables supporting different maximum modulation orders can be selected for different CSI measurement subframe sets related to the UE 104. Alternatively, when a MCS table supporting a lower maximum modulation order (e.g., 64 QAM) is selected for all CSI measurement subframe sets related to the UE 104, the same CQI table can be selected for all CSI measurement subframe sets related to the UE 104.

The method 420 continues with operation 428, in which the BS 102 transmits scheduling information back to the UE 104 including allocated resources, transport block size for data transmission, modulation and coding scheme (MCS) , and the like. In some embodiments, if the BS 102 receives a CQI index with a relatively large CQI value from the UE 104, the BS 102 transmits the data with a larger transport block size. Conversely, if the BS 102 receives a CQI index with a relatively small CQI value from the UE 104, the BS 102 transmits the data with a smaller transport block size.

In some embodiments, the BS 102 may indicate the above-described MCS table information in the DL signal explicitly (hereinafter “explicit indication” ) , implicitly (hereinafter “implicit indication’ ) , or a combination thereof. In some embodiments, explicit indication refers to some information (e.g. resource) being indicated by information in a control signal, e.g. RRC message. In some embodiments, implicit indication can be provided, for example, by the format of the bitmap in Downlink Control Information (DCI) , wherein the modulation and coding scheme Index, I_MCS, in the DCI is updated with the corresponding MCS table selected.

The method 420 continues to operation 429, where the BS 102 begins to transmit a DL signal to the UE 104 based on the selected modulation and coding scheme.

To select a CQI/MCS table for the UE 104 for uplink transmission, in accordance with an embodiment of the present disclosure, the BS 102 uses the CQI/MCS table determined for downlink transmission. As discussed above for downlink transmissions, the BS 102 effectively decides the CQI/MCS mapping table based on the CQI report from the UE 104. Since higher-order modulation is not supported for uplink transmission, when the CQI/MCS tables with maximum modulation order of the downlink transmission is 256 QAM or 1024 QAM, the maximum modulation order of CQI/MCS tables for uplink transmission is kept at the modulation order of 256 QAM. In other words, even when the maximum modulation order for downlink transmission is 1024 QAM, the maximum modulation order for uplink transmissions will be maintained at 256 QAM, in accordance with some embodiments. When the CQI/MCS tables with maximum modulation order for downlink transmission is 64 QAM, the maximum modulation order of CQI/MCS tables for uplink transmission is also 64 QAM. The BS 102 then inform the UE 104 about the MCS information including code rate, etc., through a downlink control signal, which can be transmitted on a Physical Downlink Control Channel (PDCCH) , and a Physical Downlink Shared Channel (PDSCH) .

While various embodiments of the invention have been described above, it should be understood that they have been presented by way of example only, and not by way of limitation. Likewise, the various diagrams may depict an example architectural or configuration, which are provided to enable persons of ordinary skill in the art to understand exemplary features and functions of the invention. Such persons would understand, however, that the invention is not restricted to the illustrated example architectures or configurations, but can be implemented using a variety of alternative architectures and configurations. Additionally, as would be understood by persons of ordinary skill in the art, one or more features of one embodiment can be combined with one or more features of another embodiment described herein. Thus, the breadth and scope of the present disclosure should not be limited by any of the above-described exemplary embodiments.

It is also understood that any reference to an element herein using a designation such as "first, " "second, " and so forth does not generally limit the quantity or order of those elements. Rather, these designations can be used herein as a convenient means of distinguishing between two or more elements or instances of an element. Thus, a reference to first and second elements does not mean that only two elements can be employed, or that the first element must precede the second element in some manner.

Additionally, a person having ordinary skill in the art would understand that information and signals can be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits and symbols, for example, which may be referenced in the above description can be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

A person of ordinary skill in the art would further appreciate that any of the various illustrative logical blocks, modules, processors, means, circuits, methods and functions described in connection with the aspects disclosed herein can be implemented by electronic hardware (e.g., a digital implementation, an analog implementation, or a combination of the two, which can be designed using source coding or some other technique) , various forms of program or design code incorporating instructions (which can be referred to herein, for convenience, as "software" or a "software module) , or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware, firmware or software, or a combination of these technique, depends upon the particular application and design constraints imposed on the overall system. Skilled artisans can implement the described functionality in various ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.

Furthermore, a person of ordinary skill in the art would understand that various illustrative logical blocks, modules, devices, components and circuits described herein can be implemented within or performed by an integrated circuit (IC) that can include a general purpose processor, a digital signal processor (DSP) , an application specific integrated circuit (ASIC) , a field programmable gate array (FPGA) or other programmable logic device, or any combination thereof. The logical blocks, modules, and circuits can further include antennas and/or transceivers to communicate with various components within the network or within the device. A general purpose processor can be a microprocessor, but in the alternative, the processor can be any conventional processor, controller, or state machine. A processor can also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other suitable configuration to perform the functions described herein.

If implemented in software, the functions can be stored as one or more instructions or code on a computer-readable medium. Thus, the steps of a method or algorithm disclosed herein can be implemented as software stored on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that can be enabled to transfer a computer program or code from one place to another. A storage media can be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer.

In this document, the term "module" as used herein, refers to software, firmware, hardware, and any combination of these elements for performing the associated functions described herein. Additionally, for purpose of discussion, the various modules are described as discrete modules； however, as would be apparent to one of ordinary skill in the art, two or more modules may be combined to form a single module that performs the associated functions according embodiments of the invention.

Additionally, memory or other storage, as well as communication components, may be employed in embodiments of the invention. It will be appreciated that, for clarity purposes, the above description has described embodiments of the invention with reference to different functional units and processors. However, it will be apparent that any suitable distribution of functionality between different functional units, processing logic elements or domains may be used without detracting from the invention. For example, functionality illustrated to be performed by separate processing logic elements, or controllers, may be performed by the same processing logic element, or controller. Hence, references to specific functional units are only references to a suitable means for providing the described functionality, rather than indicative of a strict logical or physical structure or organization.

Various modifications to the implementations described in this disclosure will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other implementations without departing from the scope of this disclosure. Thus, the disclosure is not intended to be limited to the implementations shown herein, but is to be accorded the widest scope consistent with the novel features and principles disclosed herein, as recited in the claims below.

Claims

A method performed by a first communication node, the method comprising:

transmitting a reference signal to a second communication node；

receiving a channel quality indicator (CQI) signal from the second communication node；

based on at least the CQI signal, determining a maximum modulation order for future signal transmissions to the second communication node； and

based on the determined maximum modulation order, determining a table configuration from among at least three predefined table configurations, wherein a first predefined table supports a first maximum modulation order, a second predefined table configuration supports a second maximum modulation order greater than the first maximum modulation order, and a third predefined table configuration supports a third maximum modulation order greater than the second maximum modulation order.
The method of claim 1 wherein the first predefined table configuration comprises a first CQI table and a first modulation code scheme (MCS) table each supporting the first maximum modulation order, the second predefined table configuration comprises a second CQI table and a second MCS table each supporting the second maximum modulation order, and the third predefined table configuration comprises a third CQI table and a third MCS table each supporting the third maximum modulation order.
The method of claim 1 further comprising:

transmitting information specifying channel state information (CSI) measurement subframe sets, each CSI measurement subframe set comprising at least one subframe in the time-frequency domain associated with channel state information reported by the second communication node； and

receiving CSI reports from the second communication node.
The method of claim 3 wherein determining a maximum modulation order is further based on the received CSI reports.
The method of claim 3 wherein information specifying CSI measurement subframe sets are transmitted in a radio resource control (RRC) message.
The method of claim 3 further comprising:

determining a modulation code scheme (MCS) table supporting the third maximum modulation order for all CSI measurement subframe sets related to the second communication node； and

determining different CQI tables supporting different maximum modulation orders for different CSI measurement subframe sets related to the second communication node.
The method of claim 3 further comprising:

determining a MCS table supporting the first maximum modulation order for all CSI measurement subframe sets related to the second communication node； and

determining a common CQI table for all CSI measurement subframe sets related to the second communication node.
The method of claim 1 wherein the first maximum modulation order corresponds to 64 quadrature amplitude modulation (QAM) , the second maximum modulation order corresponds to 256 QAM, and the third maximum modulation order corresponds to 1024 QAM.
The method of claim 1 further comprising transmitting information identifying the determined table configuration to the second communication node.
A method performed by a first communication node, the method comprising:

receiving a reference signal from a second communication node；

generating a channel quality indicator (CQI) signal based on the received reference signal；

transmitting the CQI signal to the second communication node；

receiving information identifying a table configuration from the second communication node, wherein the table configuration is determined based on at least the CQI signal and comprises one of at least three predefined table configurations, wherein a first predefined table supports a first maximum modulation order, a second predefined table configuration supports a second maximum modulation order greater than the first maximum modulation order, and a third predefined table configuration supports a third maximum modulation order greater than the second maximum modulation order.
The method of claim 10 wherein the first predefined table configuration comprises a first CQI table and a first modulation code scheme (MCS) table each supporting the first maximum modulation order, the second predefined table configuration comprises a second CQI table and a second MCS table each supporting the second maximum modulation order, and the third predefined table configuration comprises a third CQI table and a third MCS table each supporting the third maximum modulation order.
The method of claim 10 further comprising:

receiving information specifying channel state information (CSI) measurement subframe sets, each CSI measurement subframe set comprising at least one subframe in the time-frequency domain；

generating CSI reports corresponding to the CSI measurement subframe sets； and

transmitting the CSI reports to the second communication node, wherein the table configuration is determined further based on the CSI reports.
The method of claim 12 wherein information specifying the CSI measurement subframe sets are received in a radio resource control (RRC) message.
The method of claim 10 wherein the first maximum modulation order corresponds to 64 quadrature amplitude modulation (QAM) , the second maximum modulation order corresponds to 256 QAM, and the third maximum modulation order corresponds to 1024 QAM.
A first communication node, comprising:

a transceiver configured to transmit a reference signal to a second communication node, and receive a channel quality indicator (CQI) signal from the second communication node； and

at least one processor configured to:

based on at least the CQI signal, determine a maximum modulation order for future signal transmissions to the second communication node；

based on the determined maximum modulation order, determine a table configuration from among at least three predefined table configurations, wherein a first predefined table supports a first maximum modulation order, a second predefined table configuration supports a second maximum modulation order greater than the first maximum modulation order, and a third predefined table configuration supports a third maximum modulation order greater than the second maximum modulation order.
The first communication node of claim 15 wherein the first predefined table configuration comprises a first CQI table and a first modulation code scheme (MCS) table each supporting the first maximum modulation order, the second predefined table configuration comprises a second CQI table and a second MCS table each supporting the second maximum modulation order, and the third predefined table configuration comprises a third CQI table and a third MCS table each supporting the third maximum modulation order.
The first communication node of claim 15 wherein the transceiver is further configured to:

transmit information specifying channel state information (CSI) measurement subframe sets, each CSI measurement subframe set comprising at least one subframe in the time-frequency domain and associated with channel state information reported by the second communication node； and

receive CSI reports from the second communication.
The first communication node of claim 17 wherein the at least one processor is further configured to determine a maximum modulation order further based on the received CSI reports.
The first communication node of claim 17 wherein information specifying CSI measurement subframe sets are transmitted in a radio resource control (RRC) message.
The first communication node of claim 17 wherein the at least one processor is further configured to:

determine a modulation code scheme (MCS) table supporting the third maximum modulation order for all CSI measurement subframe sets related to the second communication node； and

determine different CQI tables supporting different maximum modulation orders for different CSI measurement subframe sets related to the second communication node.
The first communication node of claim 17 wherein the at least one processor is further configured to:

determine a MCS table supporting the first maximum modulation order for all CSI measurement subframe sets related to the second communication node； and

determine a common CQI table for all CSI measurement subframe sets related to the second communication node.
The first communication node of claim 15 wherein the first maximum modulation order corresponds to 64 quadrature amplitude modulation (QAM) , the second maximum modulation order corresponds to 256 QAM, and the third maximum modulation order corresponds to 1024 QAM.
The first communication node of claim 15 wherein the transceiver is further configured to transmit information identifying the determined table configuration to the second communication node.
A first communication node, comprising:

a transceiver configured to receive a reference signal from a second communication node； and

at least one processor configured to generate a channel quality indicator (CQI) signal based on the received reference signal, wherein the transceiver is further configured to:

transmit the CQI signal to the second communication node； and

receive information identifying a table configuration from the second communication node, wherein the table configuration is determined based on at least the CQI signal and comprises one of at least three predefined table configurations, wherein a first predefined table supports a first maximum modulation order, a second predefined table configuration supports a second maximum modulation order greater than the first maximum modulation order, and a third predefined table configuration supports a third maximum modulation order greater than the second maximum modulation order.
The first communication node of claim 24 wherein the first predefined table configuration comprises a first CQI table and a first modulation code scheme (MCS) table each supporting the first maximum modulation order, the second predefined table configuration comprises a second CQI table and a second MCS table each supporting the second maximum modulation order, and the third predefined table configuration comprises a third CQI table and a third MCS table each supporting the third maximum modulation order.
The first communication node of claim 24 wherein:

the transceiver is further configured to receive information specifying channel state information (CSI) measurement subframe sets, each CSI measurement subframe set comprising at least one subframe in the time-frequency domain；

the at least one processor is further configured to generate CSI reports based on the CSI measurement subframe sets, and

the transceiver is further configured to transmit the CSI reports to the second communication node, wherein determination of the table configuration is further based on the CSI measurement results.
The first communication node of claim 24 wherein information specifying the CSI measurement subframe sets are received in a radio resource control (RRC) message.
The first communication node of claim 24 wherein the first maximum modulation order corresponds to 64 quadrature amplitude modulation (QAM) , the second maximum modulation order corresponds to 256 QAM, and the third maximum modulation order corresponds to 1024 QAM.