CN104468027A - Base station device supporting data transmission based on high-order modulation and data communication method - Google Patents

Abstract

A base station device and a data communication method. The base station device includes: a receiving unit, which receives channel state information including a CQI index from a terminal device; a high-level link unit, which generates a high-level signaling signal and sends it to the terminal device. In the transmitted signal, specify whether the terminal device uses the basic CQI mapping table or the extended CQI mapping table. The extended CQI mapping table specifies the correspondence between the CQI index and the extended modulation method and code rate. The extended modulation method includes a higher modulation order High-order modulation mode; the information collection unit maps the CQI index to SINR information according to the specified CQI mapping table; the scheduling unit allocates channel resources to the terminal device and selects modulation and coding according to the mapped SINR information solution; and a sending unit, which generates a downlink transmission signal according to the scheduling result and sends it to the terminal device.

Description

Base station device and data communication method supporting data transmission based on high-order modulation

technical field

The present invention relates to a method for transmitting data from a base station as a wireless communication device to a terminal, a base station device and a terminal device. In particular, it relates to a base station device and a data communication method supporting data transmission based on high-order modulation, which can perform downlink data transmission through flexible downlink signaling configuration and use an efficient modulation and coding scheme.

Background technique

Link adaptive technology means that the information sender obtains the current channel quality information of the channel in a certain way, and based on this information, selects an appropriate modulation and coding scheme (Modulation and Coding Scheme, MCS) for the receiver, and performs channel coding on the transmitted information. , modulation and transmission to make full use of the channel capacity to achieve a higher data transmission rate. In a wireless network, the base station and the terminal (UE) agree in advance on the encoding method, code rate, and modulation method that the system may use. Decoders and modems transmit and receive data signals. If an error occurs in the indication information or the sender uses a modulation and coding scheme that is not supported by the receiver, the reception of the information will fail.

In the Long Term Evolution (LTE) standard formulated by the 3GPP organization, when the system is transmitting downlink data, the base station can choose convolutional code or Turbo code, and realize multiple possible code rates through rate matching technology. Generate a channel-coded bit stream; then the base station can choose QPSK, 16QAM or 64QAM to modulate the code bit stream, and after generating specific modulation symbols, the signal will be sent out through the antenna after subsequent multi-antenna processing. The terminal selects the corresponding demodulator and decoder according to the downlink physical layer control signaling information sent by the base station, and tries to receive the data.

The information carrying capacity of different modulation modes is different. A QPSK symbol can only carry 2 bits, while a 64QAM symbol can carry 6 bits. Since the same modulation symbol occupies the same resource element (Resource Element, RE) on the resource grid, the data transmission rate of the latter is three times that of the former under the same coding rate. At the same time, the latter is much more sensitive to interference and noise than the former, which means that when the interference or noise is strong, a large number of errors will occur in the reception of 64QAM modulation symbols, and thus offset the higher symbol load rate benefits. Therefore, the use of 64QAM for data transmission can bring benefits only under a higher signal-to-noise ratio, that is, a higher channel capacity. In 3GPP, the terminal reports quantized channel quality information called Channel Quality Indicator (CQI) to the base station by way of feedback. Based on this information, the base station determines the MCS used for data transmission. And when the channel quality is good enough, the LTE base station can use 64QAM modulated symbols for transmission. This modulation method, together with the highest code rate that can be matched with the Turbo code rate supported by the LTE system, determines the upper limit of the downlink transmission rate of the LTE system. In a typical macro cell coverage scenario, the achievable SINR of the LTE system is limited. Therefore, in the prior art, the MCS based on the modulation mode up to 64QAM has been able to fully utilize the channel capacity.

Of course, high-order modulation is not limited to 64QAM. For example, there is also 256QAM. When the number of constellation points of the modulation method increases from 64 to 256, the number of bits carried by a 256QAM symbol increases from 6 to 8, which further increases the data transmission rate by 33%. . However, because 256QAM is more sensitive to interference and is suitable for environments with higher signal-to-noise ratios, 256QAM has almost only theoretical application possibilities in the current cellular network environment where 64QAM cannot reliably cover.

On the other hand, as an effort to improve the wireless network environment, LTE Rel.12 introduced research on micro cell enhancement. The so-called micro cell refers to the cell created by the base station equipment whose signal transmission power is much smaller than that of the macro cell, and is usually used for small-scale coverage or hotspot enhancement. The micro cell may be deployed in an area where the coverage of the macro cell is unreachable, as shown in Figure 1(a), or work in a frequency band independent of the macro cell, as shown in Figure 1(b). In the scenario (a) in the example, the signal sent by 101 macro base station 1 cannot reach 103 terminal 1 (the signal strength is much smaller than the noise) due to the large fading and the blocking of building walls. At the same time, 102, the micro base station 1 uses the same carrier frequency 104 as the macro base station 1 to cover the inside of the building. At this time, the terminal 1 is very close to the micro base station 1, and will not be subject to co-channel interference from neighboring cells, and can obtain a signal-to-interference-noise ratio better than that in a traditional macro cell scenario. In the scenario illustrated in FIG. 1( b ), 101 macro base station 1 and 102 micro base station 2 work on different carrier frequencies 104 ( f1 ) and 105 ( f2 ). 103 Terminal 1 located in the micro cell can access the carrier frequency of the micro base station 2, while the signal from the macro base station 1 is filtered out. Terminal 1 can also receive signals of the same carrier frequency of other micro base stations such as micro base station 1, but if the distance is far away, the degree of attenuation is more severe than that of the useful signal of the serving cell, and terminal 1 can also receive signals that are better than those in the traditional macro cell scenario. signal-to-noise ratio. Higher SINR means higher achievable channel capacity. At this time, the existing MCS up to 64QAM in the LTE system may limit the utilization of channel capacity, so introducing a more efficient modulation method such as 256QAM or even a higher order can effectively improve the transmission efficiency of terminal 1, thereby Bring overall improvement in system performance.

At the same time, LTE has introduced various interference suppression technologies in existing versions, such as enhanced inter-cell interference cancellation or coordinated multi-point technology. These technologies can usually reduce the interference from neighboring cells, and even enhance the strength of useful signals, so as to obtain a better signal-to-interference-noise ratio than in the traditional macro cell scenario. Therefore, the introduction of a more efficient modulation method such as 256QAM may also improve the transmission efficiency of the target terminal benefiting from the existing interference suppression technology, thereby bringing about an overall improvement in system performance.

In order to introduce a new modulation method, new MCS combinations need to be defined, and these new combinations need to be supported by both the base station and the terminal and recorded in the MCS information table. At the same time, in order to ensure backward compatibility, it is still necessary to retain the original MCS table in the system. Therefore, in the new system, it is necessary to define multiple sets of MCS tables, and to define related feedback and scheduling processes for support.

In Patent Document 1 (US2009010211A1), a base station-terminal system that can support multiple sets of MCS tables is defined. In each group of different MCS tables, the same MCS scheme corresponds to different thresholds. The technical problem addressed by Patent Document 1 is that there are usually errors in CQI reporting by terminals in actual systems. In order to compensate for this error as much as possible, the base station in Patent Document 1 classifies all terminals into different levels, and then uses different MCS tables for UEs of different levels. For example, the CQI reported by a terminal at level 1 is greater than its actual SINR value, and if the MCS table corresponding to the accurate threshold is used for mapping, a higher error rate will result. Therefore, the base station selects an MCS table in which there is a positive offset between the mapping threshold of each MCS and its precise threshold, that is, only relatively higher SINR values in the table can be mapped to the MCS. By configuring different mapping thresholds for the same MCS in different tables, the base station can classify terminals and use different MCS tables to obtain more accurate mapping results and compensate the CQI estimation error of terminals to improve system performance.

However, the method of the base station in Patent Document 1 to select a suitable MCS table for different terminals is not to further utilize channel capacity to achieve a higher transmission rate, but to deal with adverse effects caused by channel estimation deviations of UEs. Different MCS tables use exactly the same combination of modulation and coding schemes, and the only difference lies in the range of the mapped SINR. The base station can use this method to effectively track the change of channel quality, but it cannot support the extended MCS scheme.

In patent document 2 (WO2012119549A1), the relationship between the new MCS table supporting 256QAM and the downlink transport block size (Transport Block Size, TBS) is described and various implementation solutions are given. On this basis, how to extend the MCS-TBS mapping of single-layer transmission to the MCS-TBS mapping relationship of multi-layer transmission is given. However, this document only provides an MCS table supporting 256QAM, but does not provide mechanisms such as a specific structure and method for supporting a new MCS table in an LTE system.

Contents of the invention

The present invention is proposed in view of the above problems, and its purpose is to provide a two-layer CQI mapping table by setting a basic CQI mapping table containing existing modulation methods and an extended CQI mapping table containing 256QAM and other high-order modulation methods. Choose between the two to improve the accuracy of CSI feedback, assist in dynamically determining the MCS scheme for downlink transmission, so as to fully utilize the channel capacity by implementing higher-order modulation methods such as 256QAM, and maintain the gap with existing mechanisms A base station device with good compatibility and a communication method in a wireless communication system.

According to one aspect of the present invention, a base station device is provided, which uses feedback information generated based on a CQI table between a wireless communication system and a terminal device to determine a modulation and coding scheme, and transmit and receive data signals, which is characterized in that it includes : a receiving unit, receiving channel state information including a CQI index representing channel quality from the terminal device; a high-level link unit, generating a high-level signaling signal and sending it to the terminal device, the high-level link unit according to the receiving unit The received channel state information specifies whether the CQI table used by the terminal device is a basic CQI mapping table or an extended CQI mapping table in the high-layer signaling transmission signal, wherein the basic CQI mapping table specifies the CQI The corresponding relationship between the index and the modulation method and the code rate, the extended CQI mapping table specifies the corresponding relationship between the CQI index, the extended modulation method and the code rate, and the extended modulation method includes the basic CQI mapping table The modulation method and the high-order modulation method whose modulation order is higher than the modulation method in the basic CQI mapping table; the information collection unit, according to the basic CQI mapping table for the terminal device specified by the high-level link unit or the extended A CQI mapping table, mapping the CQI index to signal-to-interference and noise ratio information; a scheduling unit, according to the signal-to-interference and noise ratio information mapped by the information collection unit, allocates channel resources to the terminal device and selects a modulation and coding scheme; and a sending unit, Generate a downlink transmission signal and send it to the terminal device according to the resource allocation result and the modulation and coding scheme selection result of the scheduling unit.

Therefore, the present invention improves the accuracy of CSI feedback by setting two layers of CQI mapping tables, the basic CQI mapping table containing the existing modulation method and the extended CQI mapping table containing 256QAM and other high-order modulation methods, and selecting between the two , to help dynamically determine the MCS scheme for downlink transmission, while making full use of channel capacity by implementing higher-order modulation methods such as 256QAM, it can also maintain good compatibility with existing mechanisms.

In addition, it may also be that, in the above-mentioned base station device, the terminal device is configured with at least one CSI feedback object, and the CSI feedback object is different channel state information reference signal CSI-RS resources and channel states of the terminal device in the network environment A combination of information interference measurement CSI-IM resources; the high-level link unit specifies whether the CQI table used is a basic CQI mapping table or an extended CQI mapping table for each CSI feedback object of the terminal device; the information collection unit , for each CSI feedback object of the terminal device, the CQI index is mapped to signal-to-interference and noise ratio information; the scheduling unit determines the corresponding CSI feedback object based on the signal source and interference status of the terminal device, and according to the information collection unit for The SINR information mapped by the corresponding CSI feedback object of the terminal device is used to allocate channel resources and select a modulation and coding scheme for the terminal device.

The present invention is not only aimed at the terminal, but also specifies the basic CQI mapping table or the extended CQI mapping table for the CSI feedback object of the terminal. The CSI feedback object corresponds to different channel states/interference scenarios of the terminal in the actual network environment, thus, it can The specific CSI feedback object of the specified terminal uses a specific CQI mapping table to achieve more accurate MCS scheme configuration for the terminal in the actual network environment.

In addition, in the above base station device, when the CSI feedback object of the terminal device currently uses the basic CQI mapping table, the high-level link unit judges whether the CQI value based on the current downlink transport block scheduling is equal to the basic CQI mapping table. The maximum value of CQI in the CQI mapping table, and whether the transmission rate of the MCS used in the transmission of the downlink transmission block is greater than or equal to the transmission rate corresponding to the maximum value of CQI in the basic CQI mapping table, if the results of these two judgments are both yes, Then specify an extended CQI mapping table for the CSI feedback object of the terminal device.

If the CQI value based on the current downlink transport block scheduling has not yet reached the maximum value of the CQI in the basic CQI mapping table, it means that the SINR value of the current channel of the terminal does not exceed the mapping range of the basic CQI mapping table, and there is no need to switch to a higher value. The extended CQI mapping table of the modulation method; similarly, if the transmission rate of the MCS used in the transmission of the downlink transmission block is lower than the transmission rate corresponding to the maximum value of the CQI in the basic CQI mapping table, it means that the transmission of the downlink transmission block is correct or not enough As a basis for judging the switching of the CQI mapping table, the basic CQ mapping table may continue to be used at this time. Only when the results of both judgments are yes, switch to the extended CQI mapping table based on a higher modulation mode. In this way, the present invention can make full use of the existing basic mapping table, and switch to the extended mapping table only when there is a demand for switching to the extended mapping table in a suitable network environment, thereby reducing unnecessary switching, maintaining the quantization accuracy of CSI feedback, and improving In order to make full use of channel capacity reasonably.

In addition, it may also be that, in the above base station apparatus, each of the CQI indexes corresponds to a mapping threshold, and the mapping threshold is a value reflecting a one-to-one mapping rule between CQI and SINR values; If the results of the judgment are all yes, the high-level link unit further updates the cumulative offset value S _offset according to whether the ACK/NACK information received by the receiving unit is NACK or ACK, and judges that the extended Whether the mapping threshold T _high corresponding to the CQI that uses high-order modulation and the lowest transmission rate in the CQI mapping table is smaller than the mapping threshold T _low corresponding to the CQI maximum value in the basic CQI mapping table and the updated cumulative offset The sum of the values S _offset , if T _high <T _low +S _offset , specify an extended CQI mapping table for the CSI feedback object of the terminal device, the initial value of the accumulated offset value S _offset is 0dB, if the ACK /NACK information is ACK, then the cumulative offset value S _offset is updated to S _offset = S _offset + Step _up , where Step _up is the step offset when the received information is successfully transmitted, if the ACK/NACK information is NACK, the cumulative offset value S _offset is updated to S _offset = S _offset -Step _down , where Step _down is the step offset when the information is not successfully transmitted, and Step _up and Step _down are 0.04dB to 0.2dB respectively and a fixed value within the range of 0.4dB to 1dB.

Therefore, the present invention can avoid the "ping-pong effect" that may be caused by the instantaneous judgment mechanism by setting the continuously updated cumulative value S _offset to judge whether to trigger the reconfiguration process, avoid the waste of resources, and achieve a more suitable for practical applications. Reconfiguration between CQI mapping tables.

In addition, in the above base station device, the high-level link unit first judges whether the current downlink transmission block is the first transmission before making the two judgments, and then performs the two judgments if it is the first transmission. judge.

If the current downlink transmission block is a retransmission block, it cannot be used as the basis for whether the SINR value of the current channel has exceeded the mapping range of the current CQI mapping table. Therefore, the above judgment of whether to trigger reconfiguration is only performed when it is judged to be the first transmission. , can achieve a system that is closer to the actual application requirements.

In addition, it may also be that, in the above-mentioned base station device, each of the CQI indexes corresponds to a mapping threshold, and the mapping threshold is a value reflecting a one-to-one mapping rule between CQI and SINR values; When the feedback object currently uses the extended CQI mapping table, the high-level link unit judges whether the CQI value based on the current downlink transport block scheduling is greater than or equal to the minimum CQI value of the high-order modulation method used in the extended CQI mapping table, according to the judgment As a result, update the cumulative offset value K _offset , and judge whether the mapping threshold TH _low corresponding to the maximum CQI in the basic CQI mapping table is greater than the mapping corresponding to the CQI that uses high-order modulation and has the lowest transmission rate in the extended CQI mapping table The sum of the threshold TH _high and the updated cumulative offset k _offset , if TH _low >TH _high +k _offset , specify a basic CQI mapping table for the CSI feedback object of the terminal device, and the cumulative offset value K _offset is initially The value is 0dB, if it is judged that the CQI value based on the current downlink transport block scheduling is greater than or equal to the CQI minimum value of the high-order modulation method used in the extended CQI mapping table, the cumulative offset value K _offset is updated to K _offset =K _offset +R _up , where R _up is the step offset value when receiving the CQI using high-order modulation, according to the difference between the reported CQI and the minimum CQI using high-order modulation in the extended CQI mapping table multiplied Determined by the product of the first specified value, if it is determined that the CQI value based on the current downlink transport block scheduling is smaller than the CQI minimum value of the high-order modulation method used in the extended CQI mapping table, the cumulative offset value K _offset is updated to K _offset =K _offset -R _down , where R _down is the step offset value when receiving a CQI that does not use high-order modulation, according to the minimum CQI and It is determined by multiplying the difference of the reported CQI by the product of the second specified value, the first specified value and the second specified value are any value greater than 0 and less than 1, and the second specified value is smaller than the first specified value value.

Therefore, the present invention provides a reconfiguration mechanism for switching from the extended CQI mapping table to the basic CQI mapping table, and in the reconfiguration mechanism, it is also set to judge whether to trigger the reconfiguration process based on the continuously updated cumulative value K _offset , Therefore, the "ping-pong effect" that may be caused by the instantaneous judgment mechanism can be avoided, the waste of resources can be avoided, and the reconfiguration between CQI mapping tables more suitable for practical applications can be realized.

In addition, in the base station apparatus described above, the number of CQI indexes in the basic CQI mapping table may be the same as the number of CQI indexes in the extended CQI index table.

The number of CQI indexes between the new extended CQI mapping table and the existing basic CQI mapping table is equal to keep the size of the tables consistent, which saves a lot of redesign effort in other aspects and maintains good backward compatibility.

In addition, in the above base station apparatus, the modulation schemes in the basic CQI mapping table include QPSK, 16QAM, and 64QAM, and the high-order modulation scheme is a modulation scheme with a modulation order greater than 256QAM.

The present invention also provides a data communication method in a wireless communication system corresponding to the above-mentioned base station device. The base station device and the terminal device use the feedback information generated based on the CQI table to determine a modulation and coding scheme, and send and receive data signals. It is characterized in that the data communication method includes the following steps: a receiving step, the base station device receives channel state information including a CQI index indicating channel quality from the terminal device; a high-level link step, the base station device generates a high-level signal The base station device further determines whether the CQI table used by the terminal device in the high-layer signaling transmission signal is a basic CQI mapping table or Extended CQI mapping table to specify, wherein the basic CQI mapping table specifies the corresponding relationship between the CQI index and modulation mode and code rate, and the extended CQI mapping table specifies the CQI index and extended modulation mode and code rate Correspondence between rates, the extended modulation method includes the modulation method in the basic CQI mapping table and the high-order modulation method whose modulation order is higher than the modulation method in the basic CQI mapping table; the information collection step, the The base station device maps the CQI index to signal-to-interference-noise ratio information according to the basic CQI mapping table or the extended CQI mapping table for the terminal device specified in the high-level link step; the scheduling step, the base station device collects The signal-to-interference-noise ratio information mapped in the step, allocates channel resources to the terminal device and selects a modulation and coding scheme; and a sending step, the base station device generates a downlink transmission according to the resource allocation result and the modulation and coding scheme selection result of the scheduling step signal and send it to the terminal device.

Therefore, according to the present invention, by transmitting the information used to configure the CQI mapping table based on the specific CSI feedback object on the high-level link, the network can flexibly perform the MCS table for downlink data transmission according to the interference situation of the specific terminal and the real-time transmission mode The choice of , making it possible to introduce new efficient modulation methods.

Because the present invention enhances the accuracy of feedback and scheduling, increases the upper limit of the transmission rate in the network, and is conducive to fully mining the channel capacity in a specific scene, therefore, the performance of the network can be effectively improved.

Description of drawings

Fig. 1 is a schematic diagram showing a typical scenario including micro cells and macro cells in the present invention.

Fig. 2 is an example diagram showing a basic CQI mapping table including only low-order modulation techniques in the present invention.

Fig. 3 is a schematic diagram showing a scene example of multiple CSI feedback objects configured for a terminal in the present invention.

Fig. 4 is a diagram showing an example of an extended CQI mapping table including a new high-order modulation scheme in the present invention.

FIG. 5 is an internal block diagram of a base station supporting the introduction of high-order modulation schemes in the present invention.

FIG. 6 is a diagram showing an example of a base station side RRM measurement result storage table in the present invention.

Fig. 7 is a diagram showing an example of a base station side SINR information storage table in the present invention.

Fig. 8 is a diagram showing an example of a base station side HARQ information storage table in the present invention.

FIG. 9 is an exemplary diagram showing configuration information related to CSI feedback in the base station side high-layer configuration information storage table in the present invention.

FIG. 10 is a flowchart showing switching from a basic CQI mapping table that does not include high-order modulation to an extended CQI mapping table that includes high-order modulation in the present invention.

Fig. 11 is a flow chart showing switching from an extended CQI mapping table including high-order modulation to a basic CQI mapping table not including high-order modulation in the present invention

Fig. 12 is a diagram showing an example of a base station side CQI history information storage table in the present invention.

Fig. 13 is an example diagram showing the complete base station-terminal downlink data transmission sequence in the present invention.

Fig. 14 is a diagram showing an example format of signaling information transmitted on a high-layer link involved in the present invention.

Fig. 15 is a diagram showing an exemplary flow of downlink data transmission in the present invention.

Fig. 16 is a diagram showing an example of the MCS-TBS index mapping table in the present invention.

Fig. 17 is a diagram showing an example of a TBS index-TBS mapping table in the present invention.

FIG. 18 is a diagram showing an example format of downlink control information for instructing a terminal to receive a downlink transport block using high-order modulation in the present invention.

FIG. 19 is an internal block diagram of a terminal supporting downlink data transmission using MCS based on high-order modulation in the present invention.

FIG. 20 is a diagram showing an example of CSI feedback-related configuration information in a terminal-side high-level configuration information storage table in the present invention.

FIG. 21 is an example diagram showing the flow of the CSI measurement and feedback method at the terminal side in the present invention.

Fig. 22 is a diagram showing an exemplary flow of downlink data reception in the present invention.

FIG. 23 is an example diagram of a resource grid for downlink transmission in an existing system.

Detailed ways

The concept of a cell in the present invention may be the coverage area of a base station, a sector of a base station, a home base station (micro base station), or a transmission point (TP). To simplify the description, the range covered by the base station (micro base station) is used here to represent the cell.

The concept of CSI feedback object in the present invention refers to the combination of different channel state information reference signal (CSI Reference Signal, CSI-RS) resources and channel state information interference measurement (CSI Interference Measurement, CSI-IM) resources of the terminal in the network environment . Each terminal can be configured with multiple CSI feedback objects according to different CSI-RS and CSI-IM combinations, and for each CSI feedback object, according to the signal strength measured based on its linked CSI-RS, and based on CSI- The interference intensity measured by the IM is independently calculated and reported as CSI feedback information. The specific details of the CSI feedback object will be described in detail later in conjunction with Fig. 3 and Fig. 23 .

The concept of CQI in the present invention refers to an indication of current channel quality calculated and reported by a terminal for a specific CSI feedback object. According to the previously agreed CQI mapping table, the terminal maps the calculated SINR value to CQI according to a certain method. FIG. 2 is a diagram showing an example of a CQI mapping table (basic CQI mapping table) including only low-order modulation schemes in the present invention. This table is a CQI mapping table used in the current LTE system, and specifies the modulation method 202 and coding rate 203 corresponding to each CQI index (CQI index, taking a value from 0 to 15) 201 . The table also shows the transmission efficiency 204 under the combination of the modulation mode and code rate. The basic CQI mapping table mentioned in the present invention includes but is not limited to the corresponding relationship between the CQI index and the modulation method and code rate given in this example table. The CQI mapping table (basic CQI mapping table ) as long as the correspondence between CQI, modulation scheme and code rate is specified, where the modulation scheme may be, for example, a modulation scheme with a modulation order below 64QAM, including but not limited to QPSK, 16QAM, and 64QAM. The CQI mapping process of the terminal on a specific CSI feedback object is based on the calculated SINR, and generates a combination of modulation scheme and coding rate recommended to the base station according to a certain method. The method for generating the above-mentioned mapping can be the method in the LTE system, or other realizable methods, which are well known to those skilled in the art, and are not directly related to the present invention, and will not be repeated here repeat.

Fig. 3 is a schematic diagram showing a scene example of multiple CSI feedback objects configured for a terminal in the present invention. As shown in FIG. 3 , two micro base stations 102 respectively form two adjacent cells. There is one active terminal 103 in each cell, wherein terminal 1 is located in the cell formed by micro base station 1 , and terminal 2 is located in the cell formed by micro base station 2 . The terminal 1 accesses the micro base station 1, but at the same time, because it is located at the junction of two cells, it will receive the useful signal 301 from the micro base station 1 and the interference signal 302 from the micro base station 2 at the same time. In order to improve the channel quality of the terminal 1, different scenarios may be considered, for example, the micro base station 2 may be made silent on some subframes, so as to eliminate interference to the terminal 1 on these subframes. Improving the channel quality of terminal 1 is not limited to this scenario, and other scenarios can also be considered. In order to obtain accurate CSI information for different scenarios in the scenario in Figure 3, the concept of CSI feedback objects is introduced. Different CSI feedback objects are linked to different The combination of CSI-RS resources and CSI-IM resources in different scenarios, and different combinations of CSI-RS resources and CSI-IM resources are used to reflect the channel conditions and interference conditions of useful signals in different scenarios considered , using FIG. 23 to further illustrate the concept of precise CSI feedback objects corresponding to different scenarios in FIG. 3 .

Fig. 23 is an example of a resource grid for downlink transmission in an existing system. The cell reference signal 2301 is a cell-specific reference signal and is used for physical layer measurement and channel measurement in certain transmission modes. The PDCCH resource element 2302 is used to transmit a PDCCH signal and carry downlink control information. The PDSCH resource element 2303 is used to transmit PDSCH signals and carry downlink data. In order to enhance the accuracy of CSI feedback, the network can configure multiple CSI-RS resources and CSI-IM resources for the same terminal. Taking terminal 1 in Figure 3 as an example, the strong signals it receives come from micro base station 1 and micro base station 2, so the network configures two CSI-RS resources for it, where CSI-RS resource 1 (2304) is assigned by Sent by micro base station 1, terminal 1 can measure the channel state parameters of micro base station 1-terminal 1 through this resource; CSI-RS resource 2 (2305) is sent by micro base station 2, and terminal 1 can measure micro base station 2-terminal 1 through this resource channel state parameters. At the same time, the network configures two CSI-IM resources for it, in which there is a signal sent by the micro base station 2 on the CSI-IM resource 1 (2306), and the terminal 1 can measure the interference caused by the micro base station 2 through this resource; - There is no signal sent by the micro base station 2 on the IM resource 2 (2307), and the terminal 1 can measure the interference caused by the silent state of the micro base station 2 through this resource.

In the example of configuring multiple feedback objects for terminal 1 as shown in FIG. For the situation where the signal comes from the micro base station 1 and the interference signal of the micro base station 2 exists; the combination of the CSI-RS resource 1 and the CSI-IM resource 2 linked to the CSI feedback object 2, the CSI reported by the CSI feedback object 2 is aimed at the signal When the interference signal from micro base station 1 and micro base station 2 does not exist; the combination of CSI-RS resource 2 and CSI-IM resource 2 to which CSI feedback object 3 is linked, the CSI reported by CSI feedback object 3 is aimed at the signal from micro base station The case where the interference signal of base station 2 and micro base station 1 does not exist. At this time, CSI feedback objects 1 to 3 correspond to the above three different scenarios as described above, and the SINR value and the corresponding channel capacity value of the downlink channel calculated on CSI feedback object 2 when the micro base station 2 is silent may be higher than The CSI feedback object 1 is even the reachable upper limit of the traditional LTE network, so there is a possibility that using a high-order modulation method above 256QAM can improve the reachable transmission rate of the terminal 1 when the micro base station 2 is dynamically muted. At this time, the CSI feedback object 2 can use the CQI mapping table including the new high-order modulation method of the present invention. Similarly, for the CSI feedback object 3, although the signal from the micro base station 2 is weaker than the signal from the micro base station 1, since there is no strong interference, the CQI mapping including the new high-order modulation method of the present invention can also be used sheet.

FIG. 4 is a diagram showing an example of a CQI mapping table (extended CQI mapping table) including a new high-order modulation scheme according to the present invention. The same parts as those in the CQI mapping table in FIG. 2 will be described using the same reference numerals. The table in FIG. 4 also specifies the modulation method 202 corresponding to each CQI index 201, and the table also shows the coding rate 203 corresponding to each CQI index and the transmission efficiency 204 under the combination of the modulation method and the code rate. Compared with the existing CQI mapping table in Figure 2 above, this table is characterized by adding a combination based on higher-order modulation methods such as 256QAM and different code rates and specifying the corresponding CQI index. The extended CQI mapping table that includes the new high-order modulation method of the present invention includes but not limited to the corresponding relationship between the CQI index and the modulation method and code rate given in this example table; in addition, the number of CQI index in the table of Fig. The number of CQI indexes in the table in Figure 2 is the same, all of which are 0 to 15. The number of CQI indexes between the new extended CQI mapping table and the existing basic CQI mapping table is equal to keep the tables in the same size, which will save Lots of other redesign work. The CQI mapping table (extended CQI mapping table) including the new high-order modulation method of the present invention only needs to specify the corresponding relationship between CQI, extended modulation method and code rate, wherein the so-called extended modulation method includes the above-mentioned basic CQI mapping The modulation method in the table and the higher-order modulation method with a higher modulation order than the modulation method in the basic CQI mapping table, preferably, the number of CQI indexes between the new extended CQI mapping table and the existing basic CQI mapping table is equal , the high-order modulation method here may be, for example, a modulation method with a modulation order above 256QAM. The CQI mapping process of the terminal on a specific CSI feedback object is based on the calculated SINR, and generates a combination of modulation scheme and coding rate recommended to the base station according to a certain method. Similarly, the method for generating the above-mentioned mapping can be the method in the LTE system, or other practicable methods, which are well known to those skilled in the art, and are not directly related to the present invention. Herein No longer.

Fig. 5 is an internal block diagram of the base station supporting the introduction of high-order modulation in the present invention.

As shown in Figure 5, the base station that supports the introduction of high-order modulation mainly includes: a high-level signaling configuration unit 517, a high-level information processing unit 520, a physical layer receiving unit 501, a physical layer sending unit 516, an information collection unit 502, and a CQI mapping table A decision unit 528 , a storage unit 523 , a scheduling unit 507 , a PDCCH generation unit 510 and a PDSCH generation unit 512 .

Specifically, the high-layer signaling configuration unit 517 and the high-layer information processing unit 520 are modules related to high-layer link behaviors. The high-level link refers to a virtual logical communication link established between high-level functional entities above the physical layer according to the layered model in the communication system. The high-level functional entity is used to process the information transmitted on the high-level link, and complete the communication function defined in the high-level. A typical example of the high layer described in the present invention is the radio resource control layer (Radio Resource Control layer, RRC layer) in the LTE system. The high-level signaling configuration unit 517 and the high-level information processing unit 520 are used to establish a high-level link between the base station and a specific terminal, and receive information reported by the terminal on the high-level link, such as Reference Signal Receiving Power (RSRP ) and Reference Signal Receiving Quality (Reference Signal Receiving Quality, RSRQ), and when high-level link establishment or reconfiguration is triggered, obtain and analyze the existing information stored in the storage unit 523 in the base station, so as to generate The high-level signaling information of a specific UE performs semi-static configuration on the process of the physical layer.

The process of receiving RSRP and RSRQ reporting information means that the base station extracts the data flow sent by the terminal on the high-level link through the high-level signaling receiving signal 522, and then the RSRP/RSRQ measurement report included in the high-level information processing unit 520 The processing unit 521 extracts the RSRP/RSRQ information in the data stream, and obtains the RSRP or RSRQ value measured by the terminal for each cell.

The generation process of the high-level signaling information means that the base station configures the CQI mapping table for the specific CSI feedback object of the specific terminal through the CSI feedback object and CQI table configuration unit 518 included in the high-level signaling configuration unit 517 . The above-mentioned CSI feedback object and CQI table configuration unit 518 uses the existing information of the base station to generate high-level signaling information when the high-level link establishment or reconfiguration between the base station and a specific UE is triggered, and generates channel status for a specific CSI feedback object of a specific terminal The CQI mapping table used for information is designated, and the result of the designation of the CQI mapping table is stored in the higher layer configuration information storage table 527 described later. The high-level signaling includes configuration information related to the CQI mapping table. When configuring multiple CSI feedback objects, the CQI mapping tables can be configured for different CSI feedback objects. The specific high-level signaling format will be described later. The generated high layer signaling sending signal 519 is sent to the target UE through the high layer signaling link.

By sending the high-layer signaling signal 519 including the high-layer signaling, the base station can designate a specific CSI feedback object of the terminal to use a specific CQI mapping table to obtain accurate channel quality information suitable for high-order modulation applications.

In addition, the physical layer receiving unit 501 is used to receive the data and signaling sent by the terminal in the cell to the base station through the uplink channel, complete a series of signal receiving processes such as radio frequency processing, baseband demodulation and decoding, and obtain specific uplink data and signaling information.

The physical layer sending unit 516 is used to map the generated PDSCH, PDCCH and reference signals to time-frequency resources, complete baseband-radio frequency conversion, and use multiple antennas of the base station to send downlink signals.

The physical layer receiving unit 501 and the physical layer sending unit 516, as modules for sending and receiving data at the physical layer of the base station, can be implemented by referring to related modules in traditional base stations and applying input and output hardware in existing base stations. Therefore, detailed description is omitted here.

The information collecting unit 502 is configured to collect necessary information required by the base station for configuration or resource allocation of downlink UEs. The information collection unit 502 includes: a physical layer information feedback processing unit 503, based on the information in the high-level configuration information storage table 527 stored in the storage unit 523 of the base station, to distinguish and process the information reported by different UEs in the cell based on different CSI feedback objects Feedback information; ACK/NACK collection unit 504 collects ACK/NACK information reported by different UEs in the cell and stores them in the HARQ information storage table of storage unit 523; a basic CQI mapping unit for mapping CQI to SINR based on the basic CQI mapping table 505. When the CQI mapping table configured for a specific CSI feedback object is a basic CQI mapping table, map the CQI to an SINR value and store it in the SINR information storage table 525 of the storage unit 523; and perform CQI to SINR based on the extended CQI mapping table The mapped extended CQI mapping unit 506, when the CQI mapping table configured for a specific CSI feedback object is a CQI mapping table (extended CQI mapping table) that includes a high-order modulation method, maps the CQI to an SINR value and stores it in the storage unit 523 The SINR information is stored in table 525.

The storage unit 523 is used for storing relevant information of the base station at the physical layer and high layers. The storage unit 523 stores: an RRM measurement result storage table 524, which is used to store the radio resource management (Radio Resource Management, RRM) measurement result of each active terminal in the cell, and is updated based on the output of the high-level information processing unit 520 ; The SINR information storage table 525 is used to store the signal-to-interference and noise ratio value (SINR) of the base station-terminal link of each active terminal in the cell, and is updated based on the output of the basic CQI mapping unit 505 and the extended CQI mapping unit 506; HARQ The information storage table 526 is used to store the HARQ information of all active interruptions in the network, and is updated based on the output of the ACK/NACK collection unit 504; the high-level configuration information storage table 527 is used to record the information that the base station has configured for each terminal through the high-level link. The transmitted high-level signaling information, and based on the CSI feedback object contained in the high-level signaling configuration unit 517 and the CQI table configuration unit 518, the specified result of CQI mapping table configuration for the CSI feedback object of the terminal is updated; and the CQI history storage table 529 , used to store CQI history information reported by each CSI feedback object of each active terminal in the cell. The contents of each information storage table in the storage unit will be described in detail later with reference to FIGS. 6 to 8 and FIG. 12 .

The scheduling unit 507 is used to determine the corresponding CSI feedback object based on the signal source and interference status of the terminal device in the scheduling target subframe, allocate actual channel resources and select a modulation and coding scheme, etc. The scheduling unit 507 includes an MCS/TBS mapping unit 508 and a resource allocation decision unit 509 . The resource allocation decision unit 509 first determines users who can obtain downlink time-frequency resources at a certain downlink transmission opportunity, and allocates corresponding downlink resources to each user who obtains a transmission opportunity. The MCS/TBS mapping unit 508 then determines the MCS used for downlink transmission and the corresponding transport block size (Transport Block Size, TBS) based on the resource allocation decision and the SINR value stored in the SINR information storage table 525.

The PDCCH generating unit 510 is configured to generate downlink signaling and generate corresponding downlink signals. The PDCCH generating unit 510 includes a downlink signaling generating unit 511, which generates downlink control information for a specific terminal according to the resource scheduling decision and the MCS/TBS decision of the scheduling unit 507. The downlink control information is coded and modulated to generate a downlink signal, instructing the target terminal to perform corresponding receiving behavior.

The PDSCH generating unit 512 is used for generating downlink data signals and reference signals. The PDSCH generating unit 512 includes: a data signal generating unit 513, based on the MCS/TBS decision of the scheduling unit 507, generating a transport block for each scheduled user and generating a downlink data signal through coding, modulation and subsequent processing; a reference signal The generation unit 514 is used to generate downlink reference signals such as CRS, CSI-RS and DM-RS according to high-level configuration and scheduling decisions; the downlink transmission signal generation unit 515 is used to multiplex the data signals and reference signals of each user to time-frequency resources In the grid, a downlink transmission signal is generated.

The CQI mapping table decision unit 528 is used to set an appropriate CQI mapping table for each CSI feedback object of each terminal. The CQI mapping table decision unit 528 uses the feedback information obtained by the information collection unit 502 to execute a CQI mapping table decision method for the target CSI feedback object. When the specified condition is met, the high-level reconfiguration process of the target CSI feedback object is triggered, and the basic CQI mapping table is switched to the extended CQI mapping table, or the extended CQI mapping table is switched to the basic CQI mapping table. Examples of the CQI mapping table decision-making method are shown in FIG. 10 and FIG. 11 .

In the structure of the base station in FIG. 5 , the high-level signaling configuration unit 517, the high-level information processing unit 520, and the CQI mapping table decision unit 528 correspond to the "high-level link unit", which generate high-level signaling transmission signals and send them to the terminal. According to the channel state information received by the receiving unit, the high-level link unit specifies in the high-level signaling signal whether the CQI table used by the terminal device is a basic CQI mapping table or an extended CQI mapping table, wherein the basic The CQI mapping table specifies the correspondence between the CQI index and the modulation method and the code rate, and the extended CQI mapping table specifies the correspondence between the CQI index and the extended modulation method and the code rate. The extended modulation The mode includes the modulation mode in the basic CQI mapping table and the high-order modulation mode whose modulation order is higher than the modulation mode in the basic CQI mapping table; the physical layer receiving unit 501 corresponds to the "receiving unit" and receives information from the The channel state information of the terminal device including the CQI index indicating the channel quality; the information collection unit 502 corresponds to the "information collection unit", according to the basic CQI mapping table or the extended CQI mapping table for the terminal device specified by the high-level link unit , mapping the CQI index to SINR information; the scheduling unit 507 corresponds to the "scheduling unit", and allocates channel resources to the terminal device and selects a modulation and coding scheme according to the SINR information mapped by the information collection unit; The physical layer sending unit 516, the PDCCH generating unit 510, and the PDSCH generating unit 512 correspond to the "sending unit", and generate a downlink transmission signal and send it to the terminal device according to the resource allocation result and the modulation and coding scheme selection result of the scheduling unit .

The format of the tables stored in the storage unit 523 will be described below.

FIG. 6 is an example diagram of the RRM measurement result storage table 524 at the base station side in the present invention. As shown in FIG. 6 , the RRM measurement result storage table 524 is used to record the RRM measurement results of each terminal in the current cell. Specifically, the items in the data field include: terminal ID601, which records the ID of the terminal currently associated with the cell; cell ID602, which records the ID of the cell for which the RRM measurement result reported by each terminal is targeted; The RSRP measurement result reported by each terminal for its corresponding cell ID; the RSRQ measurement result 604 records the RSRQ measurement result reported by each terminal for its corresponding cell ID.

FIG. 7 is a diagram showing an example of the SINR information storage table 525 in the present invention. As shown in FIG. 7 , the SINR information storage table 525 is used to record the channel quality information of the base station-terminal link of the active terminal in the current cell. Specifically, the items in the data field include: terminal ID701, which records the ID of the terminal currently associated with the cell; CSI feedback object ID702, which records the ID of the CSI feedback object configured for each terminal; SINR measurement result 703, which records the ID of each The specific value of the SINR measurement result 703 reported by the terminal for its configured CSI feedback object may be updated according to the mapping result of the basic CQI mapping unit 505 or the extended CQI mapping unit 506 .

FIG. 8 is a diagram showing an example of the HARQ information storage table 526 in the present invention. As shown in FIG. 8 , the HARQ information storage table 526 is used to record the HARQ process information of active terminals in the current cell. Specifically, the items in the data field include: terminal ID 801, which records the ID of the terminal currently associated with the cell; HARQ process number 802, which records the ID number of each HARQ process of each terminal. The example is FDD LTE, so the maximum number of HARQ processes that each terminal can support is 8; the redundant version number (Redundant Version, RV) 803, records the redundant version number of the data bits transmitted by a specific HARQ, which is convenient for the system to increase Redundant HARQ retransmission; MCS information 804 records the MCS used by a specific HARQ process in the last transmission.

FIG. 9 is a diagram showing an example of configuration information related to CSI feedback in the high-level configuration information storage table 527 in the present invention. The high-level configuration information storage table 527 is used to record specific high-level configuration information of all terminals that have established RRC connections in the current cell. As shown in Figure 9, the data field items related to the present invention include: terminal ID 901, which records the ID of the terminal currently associated with the cell; CSI feedback object ID 902, which records the ID of the CSI feedback object configured for each terminal; -RS resource ID 903, records the CSI-RS resource object linked to a specific CSI feedback object; CSI-IM resource ID 904, records the CSI-IM resource object linked to a specific CSI feedback object; CQI mapping table information flag 905, indicates that a specific CSI feedback object is in CQI mapping table used when generating CSI feedback information. In this example, marking the CQI mapping table information as 1 means using the basic CQI mapping table shown in FIG. 2 , and marking the CQI mapping table information as 2 means using the extended CQI mapping table shown in FIG. 4 . The high-order modulation configuration flag 906 is used to record whether the transmission function based on high-order modulation is enabled for the terminal. Only when the data field is true, the base station will configure the extended CQI mapping table and downlink transmission of high-order modulation based on the extended CQI mapping table for the corresponding terminal. There are many ways for the base station to set the high-order modulation configuration flag of the terminal. For example, it can be set according to whether the terminal has hardware capabilities such as demodulation chips that support high-order modulation (such as 256QAM). Set this flag to true if the hardware is capable, otherwise to false.

In this example, the configuration of terminal 1 (terminal ID 901 in FIG. 9 is 1) is as described above in conjunction with FIG. 3 and FIG. In 9, the terminal ID 901 is 1, and the CSI-RS resource ID 903 and CSI-IM resource ID 904 of the entry whose CSI feedback object ID 902 is 1 are both 1), that is, the CSI reported by the CSI feedback object 1 is aimed at the signal from the micro base station 1 and the micro base station The signal and interference conditions (scenario) of the interference signal of base station 2, so the CSI feedback object 1 cannot obtain a better SINR value, and a basic CQI mapping table is configured for it (the CQI mapping table information flag 905 in FIG. 9 is 1). However, due to the combination of CSI-RS resource 1 and CSI-IM resource 2 to which CSI feedback object 2 of terminal 1 is linked (in FIG. 1, CSI-IM resource ID 904 is 2), that is, the CSI reported by CSI feedback object 2 is aimed at the signal and interference situation (scenario) where the signal comes from micro base station 1 and the interference signal of micro base station 2 does not exist, so the CSI feedback object can obtain A good SINR value, but the SINR value has exceeded the mapping range of the basic CQI mapping table, so it is configured with an extended CQI mapping table (the CQI mapping table information flag 905 in FIG. 9 is 2). The method and specific process of configuring the extended CQI mapping table for terminal 1 will be described below.

Similarly, terminal 2 in the example in Figure 3 is located in the center of the serving cell, and the interference intensity from other cells is low, so the network configures only one CSI feedback object for it, and because the channel quality is good, it is also configured through the CQI mapping table The method configures an extended CQI mapping table (the CQI mapping table information flag 905 of the entry whose terminal ID is 2 and CSI feedback object ID is 1 in FIG. 9 is 2). However, the terminal N shown in Figure 9 (not shown in Figure 3) is located at the junction of multiple cells and receives many and strong interference signals. The performance is improved, so the configured CSI feedback objects can only use the basic CQI mapping table (the CQI mapping table information flag 905 of the entry whose terminal ID is N and the CSI feedback object ID is 1 or 2 in FIG. 9 is all 1).

FIG. 12 is a diagram showing an example of the CQI history information storage table 529 in the present invention. As shown in FIG. 12 , the CQI historical information storage table 529 is used to record the historical CQI reported by each CSI feedback object of the active terminal in the current cell. Specifically, the items in the data field include: terminal ID 1201, which records the ID of the terminal currently associated with the cell; CSI feedback object ID 1202, which records the ID of the CSI feedback object configured for each terminal; receiving subframe number 1203, which records the ID of the terminal The subframe indication of the CQI reported by the specific CSI feedback object is received. The CQI measurement result 1204 records the CQI measurement result reported by each terminal in a corresponding subframe for its configured CSI feedback object. The number of columns in the CQI historical information storage table 529 corresponds to the number of times the historical CQI is reported and the window size for judging whether the historical CQI is retained. Historical CQIs received earlier than the window range are continuously eliminated. The number of columns in the CQI history information storage table 529 is indicated by the ellipsis in the middle part, and can be increased or decreased according to actual conditions.

FIG. 10 is a flow chart showing the switching of the CQI mapping table from the basic CQI mapping table to the extended CQI mapping table by the high-level link in the present invention, which is executed by the CQI mapping table decision unit 528 in the base station. In order to simplify the description, the basic CQI mapping table containing only low-order modulation is defined as CQI_table _N-1 , and the extended CQI mapping table containing higher-order modulation is defined as CQI_table _N hereinafter. In the present invention, the total number of CQI_tables contained in the system supporting MCS transmission using high-order modulation is at least 2 (N is greater than or equal to 2).

The base station will only execute this method for terminals whose high-order modulation configuration flag 906 is true. Take the configuration of the CSI feedback object of the terminal 1 by the base station as an example. Since FIG. 10 shows the switching process from the basic CQI mapping table to the extended CQI mapping table, it is assumed that all CSI feedback objects of terminal 1 use the basic CQI mapping table (CQI_table _N-1 ) in the initial state.

After receiving the ACK/NACK information from the ACK/NACK collection unit 504 (step 1001), the CQI mapping table decision-making unit 528 first judges the signal and interference conditions when the corresponding downlink transport block is transmitted, and according to the high-level configuration information storage table 527 CSI-RS and CSI-IM linked by all recorded CSI feedback objects, find out the CSI feedback objects corresponding to the judged signal and interference conditions (i.e. CSI-RS and CSI-IM) (obtain the corresponding CSI feedback Object ID, step 1002). After finding the corresponding CSI feedback object, such as CSI feedback object 3, the decision-making unit judges whether the downlink transmission block is transmitted for the first time instead of retransmission based on the HARQ information storage table 526 (this judgment can adopt any feasible method in the prior art, in This will not be described in detail), and based on the high-level configuration information storage table 527, it is judged whether the CQI mapping table CQI_table _N-1 currently used by the corresponding CSI feedback object (the basic CQI mapping table shown in FIG. 2 ) has a next-level CQI mapping table CQI_table _N (ie, for example, whether the CQI mapping table information flag 905 corresponding to the CSI feedback object in the high layer configuration information storage table 527 shown in FIG. 9 is 1) (step 1003 ). If these two judgments are not all yes, the decision-making process ends; after it is judged that the downlink transmission block is the first transmission, and it is judged that the CQI mapping table CQI_table _N-1 currently used by the corresponding CSI feedback object exists in the next level CQI mapping table CQI_table _N (as shown in FIG. 9 , the CQI mapping table information flag 905 of the CSI feedback object 3 whose terminal ID is 1 is 1, indicating that it is possible to switch to the extended CQI mapping table), the decision-making unit reads this from the CQI history information storage table 529 The CQI value based on which the downlink transport block scheduling is based, and judge whether it is equal to the maximum CQI value of CQI_table _N-1 (such as CQI15 in FIG. 2 ) (step 1004 ). If not, it means that the SINR value of the current channel of the terminal does not exceed the mapping range of the basic CQI mapping table, and there is no need to switch to the extended CQI mapping table of a higher modulation mode, so the decision-making process ends; if so, the decision-making unit is further based on HARQ The information storage table 526 determines whether the transmission rate of the MCS used in the transmission of the downlink transport block is greater than or equal to the transmission rate corresponding to the maximum value of the CQI of CQI_table _N-1 (step 1005 ). If not, it means that whether the transmission of the downlink transmission block is correct or not is not enough as a basis for judging the switching of the CQI mapping table, and the decision-making process is over; if it is, it can trigger the reconfiguration process of the link between the base station and the terminal layer, which is the object of CSI feedback 3. Reconfigure the CQI mapping table as CQI_table _N (step 1010).

In the above method, after step 1005 judges yes, the reconfiguration process of the link between the base station and the terminal layer can be directly triggered, and the CQI mapping table is reconfigured as CQI_table _N for the CSI feedback object 3 (step 1010), but such a transient The judging mechanism is very likely to produce a so-called "ping-pong effect", causing the CQI mapping table to switch between the basic and extended ones, thereby causing a waste of resources.

In order to avoid such problems, the method of the present invention may also increase the judgment of whether to trigger the reconfiguration process according to the continuously updated cumulative value S _offset as shown in steps 1006-1009 in FIG. 10 . That is, if it is judged to be yes in step 1005, the decision-making unit further judges whether the feedback information is NACK or ACK (step 1006), updates the cumulative offset value S _offset according to the judgment result, and judges the value used in the extended CQI mapping table. Whether the mapping threshold T _high corresponding to the CQI with the lowest transmission rate and high-order modulation is smaller than the sum of the mapping threshold T _low corresponding to the maximum CQI value in the basic CQI mapping table and the updated cumulative offset value S _offset , that is to judge whether T _high <T _low +S _offset , if the judgment result is no, the decision-making process ends; The feedback object specifies the extended CQI mapping table.

The accumulated offset value S _offset is updated and accumulated by quantifying the effect of each downlink transmission, indicating the effect of the currently used CQI mapping table and the necessity and possibility of the next-level CQI mapping table. Specifically, the S _offset may be initialized to 0dB and dynamically updated according to downlink transmission. In the update process, if the received information is ACK, that is, the corresponding downlink transmission block is successfully received, update S _offset = S _offset + Step _up (step 1007), where Step _up is the step offset when the received information is successfully transmitted , such as 0.055dB. If the received information is NACK, that is, the corresponding downlink transmission block is not received successfully, update S _offset =S _offset -Step _down (step 1008 ), where Step _down is the step offset when the information is not successfully transmitted, such as 0.5dB. After the cumulative offset value S _offset is updated, the decision-making unit judges whether the mapping threshold T _high (such as 21dB) of the CQI that uses high-order modulation and the lowest transmission rate in CQI_table _N (such as CQI12 in Figure 4) is less than CQI_table _N- The sum of the mapping threshold T _low (for example, 19dB) of the maximum CQI value _{of 1} and the cumulative offset value S _offset (step 1009 ). If not, the decision-making process ends; if yes, the reconfiguration process of the high-level link between the base station and the terminal is triggered, and the CQI mapping table is reconfigured for the CSI feedback object 3 as CQI_table _N (step 1010 ). So far the decision-making process ends (step 1011). The above-mentioned mapping threshold T, as known to those skilled in the art, is a value that reflects a one-to-one mapping rule between CQI and SINR values, and its value can be freely determined within a certain range during implementation. For example, if the mapping threshold of CQI value 14 is determined to be 17dB, a SINR value lower than 17dB cannot be mapped to CQI14, and a SINR value higher than 17dB, if it is not higher than the mapping threshold of CQI15 (such as 19dB) , it will be mapped to CQI14.

In addition, the above step offsets Step _up and Step _down are fixed values within the ranges of 0.04dB˜0.2dB and 0.4dB˜1dB respectively. The value should be selected so that the switching of the CQI mapping table can occur after steps 1002-1005 are satisfied and a reasonable number of times is reached. The above values of 0.055dB and 0.5dB are just examples, and the value of Step _down should be greater than Step _up .

Fig. 11 is a flow chart showing that the high-level link in the present invention switches the CQI mapping table from the extended CQI mapping table to the basic CQI mapping table, that is, the method for switching the CQI mapping table of a specific CSI feedback object from CQI_table _N to CQI_table _N-1 . It is executed by the CQI mapping table decision unit 528 in the base station.

Take the base station configuring the CSI feedback object 2 of the terminal 1 as an example. It is assumed that the CSI feedback object 2 of the terminal 1 uses the extended CQI mapping table (CQI_table _N ) in the initial state. After receiving the CQI information from the physical layer feedback information processing unit 503 (step 1101), the CQI mapping table decision unit 528 first determines whether the CQI mapping table CQI_table _N used by the CSI feedback object it belongs to exists based on the high-level configuration information storage table 527 Upper level CQI mapping table CQI_table _N-1 (eg, whether the CQI mapping table information flag 905 corresponding to the CSI feedback object in the high layer configuration information storage table 527 shown in FIG. 9 is 2, step 1102 ). If not, it means that the CSI feedback object does not have an upper-level CQI mapping table, so it is naturally impossible to switch to the upper-level CQI mapping table, and the decision-making process ends; otherwise, the decision-making unit reads the downlink transmission block scheduling from the CQI history information storage table 529 time-based CQI value, and judge whether the CQI value is greater than or equal to the minimum CQI of high-order modulation in CQI_table _N (as shown in Figure 4, the minimum CQI using 256QAM is CQI12) (step 1103), and the cumulative offset value K _offset to update. The accumulated offset value K _offset is updated and accumulated by quantifying the use effect of the current CQI mapping table, and evaluates the necessity and possibility of the upper-level CQI mapping table. The K _offset may be initialized to 0dB and dynamically updated according to downlink transmission. In the update process, if the judgment result of step 1103 is yes, update K _offset =K _offset +R _up (step 1104 ), where R _up is the step offset value when receiving the CQI using high-order modulation. This value can be determined according to the difference between the reported CQI and the minimum CQI using the high-order modulation method in CQI_table _N. For example, when CQI_table _N is as shown in Figure 4, terminal 1 reports CQI=14 on CSI feedback object 2, then R _up =(14-12)*0.2=0.4dB. If the judgment result of step 1103 is negative, update K _offset =K _offset -R _down (step 1105 ), where R _down is the step offset value when receiving a CQI that does not use high-order modulation. This value can be determined according to the difference between the minimum CQI and the reported CQI of the high-order modulation method in CQI_table _N. For example, when CQI_table _N is as shown in Figure 4, terminal 1 reports CQI=10 on CSI feedback object 2, then R _donw =(12-10)*0.1=0.2dB. After the cumulative offset value K _offset is updated, the decision-making unit judges whether the mapping threshold TH _low (such as 19dB) of the maximum CQI value in CQI_table _N-1 (such as CQI15 in Figure 2) is greater than the high-order modulation used in CQI_table _N at the same time The sum of the mapping threshold TH _high (for example, 21 dB) and the cumulative offset K _offset of the CQI with the lowest transmission rate (step 1106 ). If not, the decision-making process ends; if yes, the reconfiguration process of the link between the base station and the terminal is triggered, and the CQI mapping table is reconfigured for the CSI feedback object 2 as CQI_table _N-1 (step 1107 ). So far the decision-making process ends (step 1108).

In addition, the values of the above-mentioned step offsets R _up and R _down are just examples, and the step offsets Ru _p and R _down only need to be multiplied by The product of the first specified value (0.2 in the example in Figure 11) and the difference between the minimum CQI using the high-order modulation method in the extended CQI mapping table and the reported CQI is multiplied by the second specified value (0.1 in the example in Figure 11 ), wherein the first predetermined value and the second predetermined value are arbitrary values within a range of 0 to 1, and the second predetermined value is smaller than the first predetermined value.

The method for switching the CQI mapping table from the basic CQI mapping table to the extended CQI mapping table in the high-level link shown in FIG. The methods for switching the basic CQI mapping table are all examples of methods for corresponding configuration of high-level links. The CQI mapping table configuration unit 528 described in the present invention may also use other methods to realize the corresponding configuration. For example, in step 1003 of FIG. 10 , two judgments are made whether the downlink transport block is being transmitted for the first time and whether the CSI feedback object can use the basic CQI mapping table, but the first judgment can also be omitted. In addition, the two methods shown in FIG. 10 and FIG. 11 can be combined into a data communication method in the wireless communication system of the present invention. The base station device and the terminal device transmit and receive data signals based on the modulation and coding scheme determined by the CQI table. , the data communication method includes the following steps: a receiving step, the base station device receives channel state information including a CQI index representing channel quality from the terminal device; a high-level link step, the base station device generates a high-level signaling transmission signal and send to the terminal device, the base station device also determines whether the CQI table used by the terminal device in the high-layer signaling signal is a basic CQI mapping table or an extended CQI mapping table according to the channel state information received in the receiving step The basic CQI mapping table specifies the correspondence between the CQI index and the modulation method and code rate, and the extended CQI mapping table specifies the relationship between the CQI index and the extended modulation method and code rate. Corresponding relationship, the extended modulation method includes the modulation method in the basic CQI mapping table and the high-order modulation method whose modulation order is higher than the modulation method in the basic CQI mapping table; the scheduling step, the base station device according to the The basic CQI mapping table or the extended CQI mapping table specified by the signal sent by the high-level signaling, allocates channel resources to the terminal device and selects a modulation and coding scheme; and the sending step, the base station device according to the resource allocation result and the modulation As a result of the coding scheme selection, a downlink transmission signal is generated and sent to the terminal device.

Fig. 13 is an example diagram showing the sequence of complete base station-UE downlink data transmission in the present invention. In FIG. 13 , various information exchanges that may occur in the information feedback between the base station and the terminal are exemplified as a whole, and the implementation described in the present invention can be used in some node behaviors.

As shown in FIG. 13 , when the terminal applies for downlink data transmission or the base station paging the terminal and intends to perform downlink data transmission, the two parties first establish a high-level link connection (step 1301 ).

After the base station makes a decision on the high-layer configuration based on the existing information (step 1302), it sends the generated configuration information as a high-layer signaling to the terminal through a high-layer link (step 1303). Here, the implementation of initial configuration of the CQI mapping table for each CSI feedback object of the terminal may be to directly use the basic CQI mapping table that does not include high-order modulation, or to calculate the expected wideband SINR of each CSI feedback object according to RSRP value and configure an appropriate CQI mapping table accordingly. For the latter specific method, any method known to those skilled in the art that can be realized can be adopted, and no specific description will be made in the present invention.

After receiving the corresponding configuration information through the high-layer link, the terminal performs configuration according to the high-layer signaling of the base station (step 1304), such as the configuration of CSI feedback objects, the CQI mapping table corresponding to each CSI feedback object, and the like. Based on the completed configuration, the terminal measures the channel and generates specific feedback information (step 1305), and reports the feedback information to the base station (step 1306).

So far, the initial high-level link establishment and high-level signaling transmission configuration process has been completed. After receiving the feedback information from the terminal based on high-level signaling, the base station 101 performs dynamic MCS decision-making and scheduling processes such as time-frequency resource allocation based on the feedback information (step 1307), and gives corresponding instructions to the scheduled terminal to generate downlink signaling information (step 1308).

If the terminal is scheduled, the base station sends a downlink signal to the terminal using the allocated physical layer resources (step 1309). The terminal first receives the downlink signaling information sent to itself, adjusts the data signal receiving device based on the obtained control information, receives the downlink data, and generates HARQ feedback information at the same time (step 1310 ). At the same time, the channel measurement and CSI feedback generation function (step 1305) may be performed in parallel and generate CSI feedback information. The terminal feeds back all feedback information to the base station (step 1306). This process is cyclically performed until the end of data transmission or high-level link connection reconfiguration is triggered (step 1311, the trigger conditions are shown in Fig. 10 and Fig. 11 ).

If high-layer link connection reconfiguration is triggered, the base station side performs high-layer reconfiguration and sends the generated configuration information through the high-layer link (step 1303 ). After receiving the corresponding reconfiguration information through the high-level link, the terminal performs configuration according to the new high-level signaling of the base station (step 1304), and completes channel measurement and feedback based on this configuration (step 1305). The terminal then repeats the previous physical layer process in a loop until the downlink data transmission is completed (step 1312 ). When the downlink data transmission is completed, the base station releases the high-layer link connection (step 1313), and the terminal state becomes an idle state.

In addition, the format of the high-level signaling is not particularly limited, as long as the necessary feedback mode information and configuration information in the feedback mode can be transmitted. Fig. 14 shows an example of the format of the signaling information transmitted on the high-layer link involved in the present invention.

As shown in Figure 14, the signaling information configured for the feedback part on the high-level link takes the CSI feedback object as the basic unit, and there are N groups of CSI feedback object configuration information 1401, where N is the number of CSI feedback objects configured by the base station for the terminal number. Taking the configuration information of CSI feedback object 1 as an example, the data fields contained in it specifically include: CSI-RS index1402 and CSI-IM index1403, which are respectively used to indicate the channel state information reference signal and channel state information interference corresponding to this CSI feedback object Measurement resources; CQI mapping table configuration information 1404, used to indicate the CQI mapping table configured for the CSI feedback object, that is, the mapping basis for the terminal to generate CQI; codebook configuration 1405, indicating that the base station allows the terminal to calculate CSI for the CSI feedback object A collection of precoding matrices that can be used.

Fig. 15 is an example diagram of the flow of downlink data transmission in the present invention. As shown in FIG. 15 , a complete process of downlink data transmission begins with resource scheduling by the scheduling unit, and ends with forming a downlink signal and sending it to the terminal through an antenna. The present invention takes the proportional fair scheduling method as an example to illustrate the whole process. The scheduling unit of the base station first reads the latest SINR value of each CSI feedback object of the terminal with data transmission requirements in the current base station from the SINR information storage table 525 (step 1501), then calculates their corresponding frequency band efficiency and generates a proportional fair value (Proportional Fair metric, PF metric) (step 1502). Based on the user priority obtained from the PF metric value and the load size of each user, the base station determines the terminals to be scheduled for this downlink transmission and allocates downlink time-frequency resources to them (step 1503). After generating the resource allocation decision, the base station determines the MCS used for transmission to the corresponding terminal based on the SINR of each terminal on the corresponding scheduled time-frequency resource in the SINR information storage table 525 (step 1504 ). Next, the base station obtains the corresponding TBS index value (step 1505) for each scheduled terminal through the MCS-transport block size indicator (Transport Block Size index, TBS index) mapping table through the PDSCH generation unit 512 (step 1505), according to the TBS index value and the assigned The specific TBS value is obtained from the number of resource blocks, and a specific transmission block is generated (step 1506), and a downlink data signal is generated through subsequent processing such as encoding and modulation (step 1507). At the same time, through the PDCCH generation unit 510, the base station first determines the length of downlink control information (Downlink Control Information, DCI) based on the high-order modulation configuration 906 information of each scheduled terminal, and then generates downlink control information for each scheduled terminal and sends A corresponding signal is generated (step 1508). The format of the downlink control information is shown in Figure 18. The base station multiplexes various signals and reference signals of all scheduled terminals to generate a specific downlink signal, and sends it through the antenna (step 1509 ).

Fig. 16 is an example diagram of the MCS-TBS index mapping table in the present invention. The table contains the following data fields: MCS indication 1601, indicating the MCS value used to map TBS index; modulation order 1602, indicating the number of bits carried by a single modulation symbol of the modulation mode corresponding to the MCS; TBS indication 1603, indicating the TBS of a specific MCS index mapping result. The rows corresponding to MCS0-31 in the table follow the existing MCS-TBS index mapping table. The row corresponding to MCS32-39 in the table indicates the newly added MCS using 256QAM modulation and the corresponding newly introduced TBS index.

FIG. 17 is an example diagram of a TBS index-TBS mapping table in the present invention. The table contains the following data fields: TBS indication 1701, indicating a given TBS index; resource block number 1702, indicating the total number of possible resource blocks allocated to a single terminal; TBS value 1703, indicating a resource block corresponding to a specific TBS index and a specific allocation The TBS value at the time of the number.

Fig. 18 is an example diagram of the format of the downlink control information for instructing the terminal to receive the downlink transport block from the base station in the present invention. The data field of the downlink control information follows the definition of the existing downlink control information format, including: carrier indication 1801, used to indicate the carrier corresponding to the downlink control information; resource allocation indication 1802, used to indicate the time allocated by the base station for the target terminal frequency resources; uplink power control instruction 1803, used to control the power of PUCCH transmission for the terminal; HARQ process indication 1804, used to indicate the number of the HARQ process of the scheduled downlink transmission; data stream number indication 1805, used to indicate the scheduled The port number of the downlink data transmission, the specific number of downlink data streams, etc.; the downlink transmission block specific information 1806, used to indicate the specific information of the downlink transmission block scheduled by the terminal; the PDSCH data mapping indication 1807, used to instruct the terminal when the PDSCH is not in When transmitting on the serving cell, the specific distribution of PDSCH, and the CRS signal or CSI-RS signal used to assist DMRS-based demodulation when demodulating data signals. The specific information of the downlink transmission block includes specific information of at most two downlink transmission blocks. The specific information 1808 of each transport block includes the coding and modulation mode indication 1809, which is used to indicate the coding and modulation mode used by the terminal for the downlink transport block; the new data indication 1810, which is used to indicate whether the downlink transport block is new data or retransmission ; Redundancy version indication 1811, used to indicate the redundancy version of the downlink transport block. The coding and modulation mode indication 1809 is a variable-length data field, the length of which is 5 bits when the existing MCS table is used, and 6 bits when the MCS index shown in FIG. 16 is used. When the base station generates downlink control information for a specific terminal, if the high-order modulation configuration 906 of the terminal is true, the length of the coding and modulation mode indication 1809 is 6 bits; if the high-order modulation configuration 906 of the terminal is false, the coding The modulation mode indication 1809 has a length of 5 bits.

FIG. 19 is an internal block diagram of a terminal supporting downlink data transmission using MCS based on high-order modulation in the present invention.

As shown in Figure 19, a terminal that supports MCS based on high-order modulation mainly includes: a high-level link information processing unit 1916, a channel estimation unit 1901, an interference estimation unit 1902, a radio frequency receiving unit 1910, a CSI calculation unit 1903, and a PDCCH receiving unit 1911, the PDSCH receiving unit 1914, the storage unit 1907, the uplink sending unit 1909 and so on.

Specifically, the high-level link information processing unit 1916 is a module related to high-level link behavior, used to establish a high-level link between the terminal and the serving base station, and receive information 1917 sent by the base station on the high-level link, such as CSI feedback Object configuration information, etc., according to the instructions of the base station, perform semi-static configuration on its own receiving function, and store the corresponding high-level configuration information in the storage unit 1907 .

The channel estimation unit 1901 and the interference estimation unit 1902 are respectively used to measure the CSI-RS and CSI-IM configured by the terminal to obtain signal strength information and interference strength information for subsequent CSI calculation.

The CSI calculation unit 1903 is configured to generate feedback information calculated based on a certain CSI feedback object. A terminal may have multiple CSI calculation units, which are respectively used for parallel calculation of CSI for multiple CSI feedback objects configured by the base station. The figure only depicts two CSI calculation units as an example, but the number of CSI calculation units in the present invention may be the same as the number of CSI feedback objects. The CSI calculation unit judges the CQI mapping table used by the corresponding CSI feedback object through the signaling configuration processing unit 1904, and sends the obtained signal strength information and interference strength information to the CSI calculation unit 1905 based on the basic CQI mapping table or based on the extended CQI The CSI calculation unit 1906 of the mapping table performs CSI calculation to generate CSI information to be reported.

The radio frequency receiving unit 1910 receives radio frequency signals through the antenna and converts them into baseband signals. The baseband signals are sent to the PDCCH receiving unit 1911 and the PDSCH receiving unit 1914 respectively. The former first performs operations including blind detection, demodulation and decoding through the baseband processing unit 1912 to obtain specific downlink control signaling, and generates configuration information for downlink data reception through the downlink control signaling processing unit 1913 . Based on the configuration information of the downlink control signaling processing unit 1913, the PDSCH receiving unit performs subsequent processing on the baseband signal through the baseband processing unit 1912, such as descrambling, demodulation and decoding, etc., to obtain specific data bits, and further processed by the downlink data processing unit 1915.

The storage unit 1907 is used to store various configuration information, dynamic information, and buffered data during downlink transmission. The storage unit 1907 includes a high-layer configuration information storage table 1908, which records the high-layer configuration information of the base station-terminal link. An example of part of the format related to the CSI feedback object is shown in Figure 20. The storage unit should also contain other tables, such as HARQ information storage table, HARQ data buffer, etc., which are not listed here because they are not strongly related to the present invention.

The uplink sending unit 1909 is used to send uplink signals, such as CSI feedback information carried by a Physical Uplink Control Channel (Physical Uplink Control Channel, PUCCH) or uplink data carried by a Physical Uplink Shared Channel (PUSCH). The CSI information generated by each CSI feedback object of the terminal is processed by the uplink sending unit to form an uplink signal and sent to the base station after collision processing.

FIG. 20 is a diagram showing an example of CSI feedback-related configuration information in a terminal-side high-level configuration information storage table in the present invention. Example Take the CSI feedback object configuration of terminal 1 as an example, its data field includes: CSI feedback object ID2001, indicating the ID of the CSI feedback object configured by the terminal; CSI-RS resource ID2002, recording the CSI-RS resource linked to a specific CSI feedback object Target; CSI-IM resource ID 2003, records the CSI-IM resource target linked by the specific CSI feedback object; CQI mapping table information flag 2004, records the CQI mapping table used by the specific CSI feedback object when generating CSI feedback information. Use the mark 1 of the basic CQI mapping table shown in Figure 2 in this example, use the mark 2 of the extended CQI mapping table shown in Figure 4; high-order modulation configuration flag 2005, record whether the network side has enabled the terminal based on high modulation transfer function.

Fig. 21 is a flow chart of the CSI measurement and feedback method at the terminal side in the present invention.

Taking Terminal 1 as an example, in FIG. 21 , Terminal 1 first obtains signals in the time domain and frequency domain through the receiving antenna, radio frequency and baseband processing (step 2101 ). Then the channel estimation unit 1901 of terminal 1 performs channel state parameter estimation according to the channel measurement reference signal contained therein (step 2102 ), and generates the actual CSI matrix H. At the same time, the interference estimation unit 1902 uses the interference measurement resources included in the time-frequency signal to perform interference estimation (step 2103 ), to obtain the strength of external interference at this moment.

The terminal sends the CSI matrix H and the interference intensity information to each CSI calculation unit 1903 . Taking the CSI calculation unit 1 as an example, the signaling configuration processing unit 1904 in the CSI calculation unit 1 of the terminal 1 reads the CQI mapping table information flag 2004 corresponding to the CSI feedback object stored in the high-layer configuration information storage table 1908, and judges the CSI Whether the feedback object is configured to use the extended CQI mapping table CQI_table _N (step 2104 ).

If the judgment result is "Yes", the CSI calculation unit 1903 of terminal 1 uses the CSI calculation unit 1906 based on the extended CQI mapping table to follow the existing flow and select the best RI and PMI based on the codebook (if the CSI of terminal 1 is Feedback object 1 is configured to report RI and PMI mode), calculate the SINR at this time and quantize it as CQI based on the extended CQI mapping table CQI_table _N (as shown in Figure 4 ) including high-order modulation (step 2105). For the existing traditional process, the specific description is omitted.

If the judgment result is "No", the CSI calculation unit 1903 of terminal 1 uses the CSI calculation unit 1905 based on the basic CQI mapping table to follow the existing flow and select the best RI and PMI based on the codebook (if the CSI of terminal 1 is Feedback object 1 is configured to report RI and PMI mode), calculate the SINR at this time and quantize it as CQI based on the basic CQI mapping table CQI_table _N-1 (as shown in Figure 2) (step 2106). For the existing traditional process, the specific description is omitted.

The generated CSI information is stored in the storage unit 1907, and sent to the base station through an uplink channel after waiting for an appropriate feedback opportunity (step 2107).

Fig. 22 is an example diagram of the process of receiving downlink data in the present invention. As shown in Figure 22, a complete process of receiving downlink data starts from the terminal receiving the radio frequency signal through the antenna to decoding the data information contained in the PDSCH. The terminal first receives the radio frequency signal from the base station device through the radio frequency receiving unit, converts it into a baseband signal and sends it to the PDCCH receiving unit and the PDSCH receiving unit (step 2201). Then the terminal judges the length of the downlink control information according to the high-order modulation configuration 2005 through the PDCCH receiving unit (step 2202). The length of the downlink control information is variable and determined by the length of the coding and modulation mode indication 1809 in the information. When the data field of the high-order modulation configuration 2005 is true, the coded modulation mode indication 1809 in the downlink control information has a length of 6 bits. When the data field of the high-order modulation configuration 2005 is false, the coded modulation mode indication 1809 in the downlink control information has a length of 5 bits. And based on the length information, a detection attempt is made on the PDCCH until the downlink control information targeting itself is successfully received (step 2203 ). Based on the downlink control information, the terminal obtains the MCS index used by each transmission block (step 2204). Then the terminal obtains the corresponding TBS index value and the modulation method used based on the MCS-transport block size indicator (Transport Block Size index, TBS index) mapping table through the downlink control signaling processing unit 1913, and then according to the TBS index value and the assigned The specific TBS value is obtained from the number of resource blocks, and the channel coding rate of the transport block is calculated by using the TBS value (step 2205). After obtaining the information, the terminal selects an appropriate demodulator and decoder through the PDSCH receiving unit (step 2206), and performs subsequent demodulation and decoding processing on the PDSCH signal, and finally obtains the downlink data carried in the PDSCH (step 2207) .

That is, the present invention also provides a downlink data receiving device in a terminal device, which receives a data signal from the base station device based on a modulation and coding scheme specified by the base station device, including: a radio frequency receiving unit that receives the data signal from the base station device The radio frequency signal is converted into a baseband signal and then sent to the PDCCH receiving unit and the PDSCH receiving unit; the PDCCH receiving unit indicates whether the base station device specifies that the terminal device can use a high-order modulation method according to the information stored in the terminal device The high-order modulation configuration flag, judge the length of the downlink control information from the base station device, and perform a PDCCH detection attempt on the baseband signal received from the radio frequency receiving unit based on the determined length of the downlink control information, until successfully receiving the downlink control information targeted at the terminal device, and obtaining the modulation and coding scheme used by the base station device based on the downlink control information; the PDSCH receiving unit, according to the modulation obtained by the PDCCH receiving unit The coding scheme determines the modulation method and channel coding rate used by the base station device, selects an appropriate demodulator and decoder, and performs demodulation, decoding and other processing on the baseband signal received from the radio frequency receiving unit to obtain Downlink data of the base station device.

According to another aspect of the present invention, there is also provided a method for receiving downlink data in a terminal device. Based on the modulation and coding scheme specified by the base station device, receiving a data signal from the base station device includes the following steps: in the terminal device The radio frequency receiving unit receives the radio frequency signal from the base station device, and converts it into a baseband signal and sends it to the PDCCH receiving unit and the PDSCH receiving unit; the PDCCH receiving unit represents the base station according to the terminal device stored Whether the device specifies that the terminal device can use the high-order modulation configuration flag of the high-order modulation mode, judge the length of the downlink control information from the base station device, and determine the length of the downlink control information received from the radio frequency based on the determined length of the downlink control information The baseband signal received by the unit performs a PDCCH detection attempt until the downlink control information targeted at the terminal device is successfully received, and based on the downlink control information, the step of obtaining the modulation and coding scheme used by the base station device; and the PDSCH The receiving unit determines the modulation scheme and channel coding code rate used by the base station device according to the modulation and coding scheme obtained by the PDCCH receiving unit, selects an appropriate demodulator and decoder, and performs the reception from the radio frequency receiving unit The step of performing demodulation, decoding and other processing on the received baseband signal to obtain downlink data from the base station device.

Preferably, in the above-mentioned downlink data receiving device or method, the high-order modulation configuration flag indicates that when the base station device specifies that the terminal device can use the high-order modulation mode, the length of the downlink control information is 6 bits The high-order modulation configuration flag indicates that when the base station device does not specify that the terminal device can use the high-order modulation mode, the length of the downlink control information is 5 bits.

In addition, preferably, in the above-mentioned downlink data receiving device or method, the high-order modulation scheme is a modulation scheme with a modulation order above 256QAM.

In the method and device that can support high-order modulation, the new MCS combination introduces additional bits, so some new items need to be added to the existing DCI format bit size table on both the base station and the terminal side, because during downlink transmission Whether the MCS used is based on 256QAM will bring new possibilities to the bit size of each defined DCI format. Therefore, the terminal needs to add a step of determining the length of the downlink control information from the base station device before receiving DCI (for example, step 2202 in Figure 22), and the high-order modulation configuration flags defined in Table 906 and Table 2005, which The role is to indicate whether each terminal is "available" for high-order modulation. According to the present invention, the downlink data receiving device in the terminal judges the length of the downlink control information based on the high-order modulation configuration flag, and then can properly receive the downlink control information based on the extended DCI format bitsize table, realizing the use of high-order modulation downlink transmission.

According to the present invention, since the efficient transmission technology based on high-order modulation is introduced in the physical layer, the channel capacity can be more fully utilized and a better data transmission rate can be obtained. At the same time, by setting the high-level link to transmit the configuration information of the CQI mapping table fed back by the terminal, the terminal can respond to changes in channel quality in a timely manner. While enhancing the coverage of the feedback information on the channel quality, it ensures that the feedback information is consistent with the channel quality. Accuracy of scheduling decisions. Therefore, the performance of the network can be effectively improved.

Claims (16)

1. A base station device, which utilizes feedback information based on a CQI table to generate between a wireless communication system and a terminal device, determines a modulation and coding scheme, and transmits and receives data signals, characterized in that it includes: a receiving unit, receiving channel state information including a CQI index indicating channel quality from the terminal device; A high-level link unit, which generates a high-level signaling transmission signal and sends it to the terminal device. The high-level link unit uses the high-level signaling transmission signal for the terminal device according to the channel state information received by the receiving unit. Specify whether the CQI table is a basic CQI mapping table or an extended CQI mapping table, where the basic CQI mapping table specifies the correspondence between the CQI index and the modulation scheme and code rate, and the extended CQI mapping table specifies the The correspondence between the CQI index and the extended modulation method and code rate, the extended modulation method includes the modulation method in the basic CQI mapping table and the high-order modulation order higher than the modulation method in the basic CQI mapping table Modulation; The information collection unit maps the CQI index to SINR information according to the basic CQI mapping table or the extended CQI mapping table for the terminal device specified by the high-level link unit; The scheduling unit allocates channel resources to the terminal device and selects a modulation and coding scheme according to the signal-to-interference-noise ratio information mapped by the information collection unit; and The sending unit generates a downlink transmission signal and sends it to the terminal device according to the resource allocation result and the modulation and coding scheme selection result of the scheduling unit. 2. The base station apparatus according to claim 1, wherein: The terminal device is configured with at least one CSI feedback object, and the CSI feedback object is a combination of different channel state information reference signal CSI-RS resources and channel state information interference measurement CSI-IM resources of the terminal device in the network environment; The high-level link unit specifies whether the CQI table used is a basic CQI mapping table or an extended CQI mapping table for each CSI feedback object of the terminal device; The information collection unit maps the CQI index to signal-to-interference-noise ratio information for each CSI feedback object of the terminal device; The scheduling unit determines the corresponding CSI feedback object based on the signal source and the interference condition of the terminal device, and performs channel processing for the terminal device according to the signal-to-interference-noise ratio information mapped by the information collection unit to the corresponding CSI feedback object of the terminal device. Resource allocation and selection of modulation and coding schemes. 3. The base station apparatus according to claim 2, wherein: When the CSI feedback object of the terminal device currently uses the basic CQI mapping table, The high-level link unit judges whether the CQI value based on the current downlink transport block scheduling is equal to the maximum CQI value in the basic CQI mapping table, and whether the transmission rate of the MCS used for the downlink transport block transmission is greater than or equal to the basic CQI mapping table The transmission rate corresponding to the maximum value of the CQI, If the results of the two judgments are both yes, specify an extended CQI mapping table for the CSI feedback object of the terminal device. 4. The base station apparatus according to claim 3, wherein: Each of the CQI indexes corresponds to a mapping threshold, and the mapping threshold is a value reflecting a one-to-one mapping rule between CQI and SINR values; If the results of the two judgments are both yes, the high-level link unit further updates the cumulative offset value S _offset according to whether the ACK/NACK information received by the receiving unit is NACK or ACK, And judge whether the mapping threshold T _high corresponding to the CQI that uses high-order modulation and has the lowest transmission rate in the extended CQI mapping table is smaller than the mapping threshold T _low corresponding to the CQI maximum value in the basic CQI mapping table and the updated The sum of the accumulated offset values S _offset , if T _high <T _low +S _offset , specify an extended CQI mapping table for the CSI feedback object of the terminal device, The initial value of the cumulative offset value S _offset is 0dB, If the ACK/NACK information is ACK, the cumulative offset value S _offset is updated to S _offset = S _offset + Step _up , where Step _up is the step offset when the received information is successfully transmitted, If the ACK/NACK information is NACK, the cumulative offset value S _offset is updated to S _offset = S _offset - Step _down , where Step _down is the step offset when the information is not successfully transmitted, Step _up and Step _down are fixed values within the range of 0.04dB to 0.2dB and 0.4dB to 1dB respectively. 5. The base station apparatus according to claim 3, wherein: Before performing the two determinations, the high-level link unit first determines whether the current downlink transmission block is the first transmission, and then performs the two determinations if it is the first transmission. 6. The base station apparatus according to claim 2, wherein: Each of the CQI indexes corresponds to a mapping threshold, and the mapping threshold is a value reflecting a one-to-one mapping rule between CQI and SINR values; When the CSI feedback object of the terminal device currently uses the extended CQI mapping table, The high-level link unit judges whether the CQI value based on the current downlink transport block scheduling is greater than or equal to the minimum CQI value of the high-order modulation method used in the extended CQI mapping table, and updates the cumulative offset value K _offset according to the judgment result, and Determine whether the mapping threshold TH _low corresponding to the CQI maximum value in the basic CQI mapping table is greater than the mapping threshold TH _high corresponding to the CQI that uses high-order modulation and has the lowest transmission rate in the extended CQI mapping table and the updated cumulative offset k _offset The sum, if TH _low >TH _high +k _offset , then specify the basic CQI mapping table for the CSI feedback object of the terminal device, The initial value of the cumulative offset value K _offset is 0dB, If it is determined that the CQI value based on the scheduling of the current downlink transport block is greater than or equal to the minimum CQI value of the high-order modulation method used in the extended CQI mapping table, the cumulative offset value K _offset is updated to K _offset = K _offset +R _up , where R _up is the step offset value when receiving the CQI using high-order modulation, according to the difference between the reported CQI and the minimum CQI using high-order modulation in the extended CQI mapping table multiplied by the first regulation The product of the values is determined, If it is determined that the CQI value based on the scheduling of the current downlink transport block is smaller than the minimum CQI value of the high-order modulation method used in the extended CQI mapping table, the cumulative offset value K _offset is updated as K _offset = K _offset - R _down , where R _down is the step offset value when receiving a CQI that does not use high-order modulation, according to the second regulation multiplied by the difference between the minimum CQI using high-order modulation and the reported CQI in the extended CQI mapping table The product of values determines, The first predetermined value and the second predetermined value are arbitrary values greater than 0 and less than 1, and the second predetermined value is smaller than the first predetermined value. 7. The base station apparatus according to any one of claims 1 to 6, wherein: The number of CQI indexes in the basic CQI mapping table is the same as the number of CQI indexes in the extended CQI index table. 8. The base station apparatus according to any one of claims 1 to 6, wherein: The modulation modes in the basic CQI mapping table include QPSK, 16QAM, and 64QAM, and the high-order modulation mode is a modulation mode with a modulation order above 256QAM. 9. A data communication method in a wireless communication system, using feedback information generated based on a CQI table between a base station device and a terminal device to determine a modulation and coding scheme, and to send and receive data signals, characterized in that the data communication method Including the following steps: A receiving step, wherein the base station device receives channel state information including a CQI index indicating channel quality from the terminal device; In the high-level link step, the base station device generates a high-level signaling transmission signal and sends it to the terminal device, and the base station device also performs the high-level signaling transmission signal in the high-level signaling transmission signal according to the channel state information received in the receiving step. Specify whether the CQI table used by the terminal device is a basic CQI mapping table or an extended CQI mapping table, wherein the basic CQI mapping table specifies the correspondence between the CQI index, modulation mode, and code rate, and the extended CQI mapping table The corresponding relationship between the CQI index and the extended modulation method and code rate is specified, and the extended modulation method includes the modulation method in the basic CQI mapping table and the modulation with a higher modulation order than in the basic CQI mapping table The high-order modulation mode of the mode; An information collection step, wherein the base station device maps the CQI index to signal-to-interference-noise ratio information according to the basic CQI mapping table or the extended CQI mapping table for the terminal device specified in the high-level link step; In a scheduling step, the base station device allocates channel resources to the terminal device and selects a modulation and coding scheme according to the signal-to-interference-noise ratio information mapped in the information collection step; and In the sending step, the base station device generates a downlink transmission signal and sends it to the terminal device according to the resource allocation result and the modulation and coding scheme selection result in the scheduling step. 10. The data communication method as claimed in claim 9, characterized in that, The terminal device is configured with at least one CSI feedback object, and the CSI feedback object is a combination of different channel state information reference signal CSI-RS resources and channel state information interference measurement CSI-IM resources of the terminal device in the network environment; In the high-level link step, for each CSI feedback object of the terminal device, specify whether the CQI table used is a basic CQI mapping table or an extended CQI mapping table; In the information collection step, for each CSI feedback object of the terminal device, the CQI index is mapped to signal-to-interference-noise ratio information; In the scheduling step, the corresponding CSI feedback object is determined based on the signal source and interference status of the terminal device, and the terminal device is processed according to the signal-to-interference-noise ratio information mapped to the corresponding CSI feedback object of the terminal device in the information collection step Channel resource allocation and selection of modulation and coding schemes. 11. The data communication method as claimed in claim 10, characterized in that, When the CSI feedback object of the terminal device currently uses the basic CQI mapping table, The high-level link step judges whether the CQI value based on the current downlink transport block scheduling is equal to the CQI maximum value in the basic CQI mapping table, and whether the transmission rate of the MCS used for the downlink transport block transmission is greater than or equal to the basic CQI mapping table The transmission rate corresponding to the maximum value of the CQI, If the results of the two judgments are both yes, specify an extended CQI mapping table for the CSI feedback object of the terminal device. 12. The data communication method as claimed in claim 11, characterized in that, Each of the CQI indexes corresponds to a mapping threshold, and the mapping threshold is a value reflecting a one-to-one mapping rule between CQI and SINR values; In the case that the results of the two judgments are both yes, the high-level link step further updates the cumulative offset value S _offset according to whether the ACK/NACK information received in the receiving step is NACK or ACK, And judge whether the mapping threshold T _high corresponding to the CQI that uses high-order modulation and has the lowest transmission rate in the extended CQI mapping table is smaller than the mapping threshold T _low corresponding to the CQI maximum value in the basic CQI mapping table and the updated The sum of the accumulated offset values S _offset , if T _high <T _low +S _offset , specify an extended CQI mapping table for the CSI feedback object of the terminal device, The initial value of the cumulative offset value S _offset is 0dB, If the ACK/NACK information is ACK, the cumulative offset value S _offset is updated to S _offset = S _offset + Step _up , where Step _up is the step offset when the received information is successfully transmitted, If the ACK/NACK information is NACK, the cumulative offset value S _offset is updated to S _offset = S _offset - Step _down , where Step _down is the step offset when the information is not successfully transmitted, Step _up and Step _down are fixed values within the range of 0.04dB to 0.2dB and 0.4dB to 1dB respectively. 13. The data communication method as claimed in claim 11, characterized in that, In the high-level link step, before making the two judgments, first judge whether the current downlink transmission block is the first transmission, and then make the two judgments if it is the first transmission. 14. The data communication method as claimed in claim 9, characterized in that, Each of the CQI indexes corresponds to a mapping threshold, and the mapping threshold is a value reflecting a one-to-one mapping rule between CQI and SINR values; When the CSI feedback object of the terminal device currently uses the extended CQI mapping table, The high-level link step judges whether the CQI value based on the current downlink transport block scheduling is greater than or equal to the minimum CQI value of the high-order modulation method used in the extended CQI mapping table, and updates the cumulative offset value K _offset according to the judgment result, and Determine whether the mapping threshold TH _low corresponding to the CQI maximum value in the basic CQI mapping table is greater than the mapping threshold TH _high corresponding to the CQI that uses high-order modulation and has the lowest transmission rate in the extended CQI mapping table and the updated cumulative offset k _offset The sum, if TH _low >TH _high +k _offset , then specify the basic CQI mapping table for the CSI feedback object of the terminal device, The initial value of the cumulative offset value K _offset is 0dB, If it is determined that the CQI value based on the scheduling of the current downlink transport block is greater than or equal to the minimum CQI value of the high-order modulation method used in the extended CQI mapping table, the cumulative offset value K _offset is updated to K _offset = K _offset +R _up , where R _up is the step offset value when receiving the CQI using high-order modulation, according to the difference between the reported CQI and the minimum CQI using high-order modulation in the extended CQI mapping table multiplied by the first regulation The product of the values is determined, If it is determined that the CQI value based on the scheduling of the current downlink transport block is smaller than the minimum CQI value of the high-order modulation method used in the extended CQI mapping table, the cumulative offset value K _offset is updated as K _offset = K _offset - R _down , where R _down is the step offset value when receiving a CQI that does not use high-order modulation, according to the second regulation multiplied by the difference between the minimum CQI using high-order modulation and the reported CQI in the extended CQI mapping table The product of values determines, The first predetermined value and the second predetermined value are arbitrary values greater than 0 and less than 1, and the second predetermined value is smaller than the first predetermined value. 15. The data communication method according to any one of claims 9 to 14, wherein: The number of CQI indexes in the basic CQI mapping table is the same as the number of CQI indexes in the extended CQI index table. 16. The data communication method according to any one of claims 9 to 14, wherein: The modulation modes in the basic CQI mapping table include QPSK, 16QAM, and 64QAM, and the high-order modulation mode is a modulation mode with a modulation order above 256QAM.