CN115242348A - Adaptive link modulation coding method, system and base station - Google Patents
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Abstract
The application provides a method, a system and a base station for adaptive link modulation coding, the method is applied to user equipment and the base station in a communication system, the user equipment is in communication connection with the base station, and the method comprises the following steps: the base station acquires feedback information from the user equipment; the base station adjusts the modulation and coding strategy value of the communication between the base station and the user equipment according to the link modulation and coding adjustment strategy and the feedback information, can adjust MCS according to the positive feedback and the negative feedback of the channel, does not need to carry out CQI measurement and LUT query, and improves the link throughput when the user equipment is communicated with the base station.
Description
Technical Field
The present application relates to the field of wireless communication technologies, and in particular, to a method, a system, and a base station for adaptive link modulation coding.
Background
In a wireless communication system, a Base Station (BS) and a User Equipment (UE) communicate over a wireless air interface. Meanwhile, the wireless air interface channel condition may be affected by factors such as distance, which may cause the communication channel condition between the base station and the user equipment to be unstable. Therefore, modulation and Coding Scheme (MCS) values need to be adjusted in real time according to channel conditions to achieve the purpose of utilizing communication link capability as much as possible and avoiding link failure.
Currently, a modulation and coding strategy requires a base station to perform a Look-Up Table (Look-Up-Table, LUT) to select a corresponding MCS value according to a Channel Quality Indicator (CQI) measured by a user equipment. Since the relation of CQI and MCS value in LUT is fixed, accurate MCS value cannot be provided for different channel conditions.
Disclosure of Invention
Accordingly, there is a need for an adaptive link modulation coding method, system, and storage medium. The MCS of the base station and the user equipment during communication can be adjusted according to the positive feedback (ACK) and the Negative feedback (NACK) of the channel, CQI measurement and LUT query are not needed, and the link throughput of the user equipment and the base station during communication is improved.
In a first aspect, an adaptive link modulation and coding method provided in an embodiment of the present application is applied to a user equipment and a base station in a 5G communication system, where the user equipment is communicatively connected to the base station, and the method includes:
the base station acquires feedback information from the user equipment, wherein the feedback information comprises positive feedback or negative feedback;
the base station is used for adjusting the modulation and coding strategy value of the communication between the base station and the user equipment according to the link modulation and coding adjustment strategy and the positive feedback or the negative feedback.
In one possible implementation manner of this application, the feedback information includes positive feedback or negative feedback, and the method further includes:
the user equipment carries out cyclic redundancy check;
if the user equipment passes the cyclic redundancy check, forward feedback is sent to the base station;
and if the user equipment does not pass the cyclic redundancy check, negative feedback is sent to the base station.
In one possible implementation manner of the present application, the modulation and coding strategy value includes a modulation order and a channel coding rate; the link modulation coding adjustment strategy comprises:
if the feedback information acquired by the base station is forward feedback, improving the modulation order and the channel coding rate;
and if the feedback information acquired by the base station is negative feedback, reducing the modulation order and the channel coding rate.
In one possible implementation manner of the present application, the method further includes:
the base station counts the quantity of the positive feedback and the negative feedback;
and if the positive feedback is continuous and the number of the positive feedback is higher than a first threshold value, increasing the modulation order and the channel coding rate, and clearing the number of the positive feedback and the negative feedback.
In one possible implementation manner of the present application, the method further includes:
and if the ratio of the number of the negative feedback to the number of the positive feedback and the negative feedback is higher than a second threshold, reducing the modulation order and the channel coding rate, and clearing the number of the positive feedback and the negative feedback.
In one possible implementation manner of the present application, the base station includes a lookup table; the method further comprises the following steps:
the base station acquires an initial signal-to-noise ratio from the user equipment;
the base station performs table lookup according to the initial signal-to-noise ratio and a lookup table to obtain a first modulation and coding strategy value initial interval;
the base station selects a first modulation and coding strategy value in the first modulation and coding strategy value initial interval;
and the base station communicates with the user equipment according to the first modulation and coding strategy value.
In one possible implementation manner of the present application, the method further includes:
the base station acquires an uplink signal-to-noise ratio from the user equipment;
the base station inputs the uplink signal-to-noise ratio to a Gaussian filter to obtain an average signal-to-noise ratio;
the base station performs table lookup according to the average signal-to-noise ratio and the lookup table to acquire a second modulation and coding strategy value initial interval;
the base station selects a second modulation and coding strategy value in the second modulation and coding strategy value initial interval;
and the base station communicates with the user equipment according to the second modulation and coding strategy value.
In one possible implementation manner of this application, the base station further includes an uplink and downlink power conversion factor, and the method further includes:
the base station converts the uplink signal-to-noise ratio into a downlink signal-to-noise ratio according to the uplink signal-to-noise ratio and the uplink and downlink power conversion factors;
and the base station adjusts the modulation and coding strategy value according to the downlink signal-to-noise ratio.
In a second aspect, an adaptive link modulation coding system provided in an embodiment of the present application includes a base station and a user equipment, where the base station and the user equipment are communicatively connected;
the user equipment is used for sending feedback information to the base station, wherein the feedback information comprises positive feedback and negative feedback;
the base station is configured to perform the adaptive link modulation coding method according to the first aspect.
In a third aspect, an embodiment of the present application provides a base station, the base station is communicatively connected to a user equipment, and the base station is configured to perform the adaptive link modulation coding method according to the first aspect.
The embodiment of the application provides a method, a system and a base station for modulating and coding a self-adaptive link. The MCS of the base station and the user equipment during communication can be adjusted according to the ACK and the NACK of the channel without CQI measurement and LUT query, so that the link throughput of the user equipment and the base station during communication is improved.
Drawings
Fig. 1 is a schematic diagram of an adaptive link modulation and coding system according to an embodiment of the present application.
Fig. 2 is a flowchart of an adaptive link modulation coding method according to an embodiment of the present application.
Fig. 3 is a flowchart of an adaptive link modulation coding method according to another embodiment of the present application.
Fig. 4 is a flowchart of an adaptive link modulation coding method according to another embodiment of the present application.
Description of the main elements
Adaptive link modulation coding system 10
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments of the present application.
In the embodiments of the present application, "at least one" means one or more, and a plurality means two or more. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.
It should be noted that in the embodiments of the present application, the terms "first", "second", and the like are used for distinguishing between descriptions and not necessarily for describing a relative importance or order, respectively. The features defined as "first", "second" may explicitly or implicitly include one or more of the features described. In the description of the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or illustrations. Any embodiment or design described herein as "exemplary" or "such as" is not necessarily to be construed as preferred or advantageous over other embodiments or designs. Rather, use of the word "exemplary" or "such as" is intended to present concepts related in a concrete fashion.
All other embodiments that can be obtained by a person skilled in the art without inventive step based on the embodiments in this application are within the scope of protection of this application.
In a wireless communication system, a Base Station (BS) and a User Equipment (UE) communicate over a wireless air interface. Meanwhile, the wireless air interface channel condition may be affected by factors such as distance, which may cause the communication channel condition between the base station and the user equipment to be unstable. Therefore, modulation and Coding Scheme (MCS) values need to be adjusted according to channel conditions in real time.
Currently, when a ue communicates with a base station, the base station first issues a Channel State Information-Reference Signal (CSI-RS) to the ue. The ue needs to accurately measure a Channel according to the CSI-RS, and send a measured Channel Quality Indicator (CQI) to the base station. The base station selects a corresponding MCS value in a Look-Up Table (Look-Up-Table, LUT) according to a Channel Quality Indicator (CQI) measured by the user equipment. The LUT is a table in which Channel Quality Indicators (CQIs) and corresponding MCS values are stored. Obviously, since the relation of CQI and MCS value in LUT is fixed, accurate MCS value cannot be provided for different channel conditions. Therefore, the present application provides a method for adaptive link modulation and coding, which can adjust MCS when a base station communicates with a user equipment according to positive feedback (ACK) and Negative feedback (NACK) of a channel, without performing CQI measurement and LUT query, improve link throughput when the user equipment communicates with the base station, and reduce the probability of link connection failure.
Some embodiments of the application are described in detail below with reference to the accompanying drawings. The embodiments described below and the features of the embodiments can be combined with each other without conflict.
Fig. 1 is a system diagram of an Adaptive Modulation and Coding (AMC) system 10 according to an embodiment of the present application, and as shown in fig. 1, the AMC system 10 includes the following components: a base station 100 and a user equipment 200. Wherein the base station 100 and the user equipment 200 are communicatively connected.
In the following embodiments, the AMC system 10 according to the present invention will be described by taking a downlink and an uplink as examples.
In the downlink, after establishing a connection with the ue 200, the base station 100 does not need to send the CSI-RS to the ue 200, but receives feedback information from the ue 200, where the feedback information includes a positive feedback ACK or a negative feedback NACK. The base station 100 adjusts the MCS value communicated between the base station 100 and the user equipment 200 according to the feedback information (i.e., ACK or NACK).
It can be understood that the MCS value specifically includes a modulation order and a channel coding rate. When the base station 100 and the user equipment 200 are communicating, the higher the modulation order and the channel coding rate, the higher the transmission rate that can be provided. However, the higher the requirement for channel conditions for high modulation order and high channel coding rate. Therefore, the modulation order and the channel coding rate need to be adjusted according to the channel condition to obtain the optimal link throughput under the current channel condition.
Wherein the positive feedback or the negative feedback is generated by the user equipment 200 when performing a Cyclic Redundancy Check (CRC). CRC is a channel coding technique that generates a short fixed bit check code from data, such as network packets or computer files, to detect or verify errors that may occur after data transmission or storage. If the ue 200 determines that the CRC passes the downlink signal of the base station 100, it indicates that the ue 200 can receive the downlink signal and correctly decode the downlink signal, and sends an ACK to the base station 100. If the ue 200 fails the crc, it indicates that the data transmitted between the ue 200 and the base station 100 cannot be decoded correctly, and sends NACK to the base station 100.
Due to the standards set by the third Generation Partnership project (3 rd Generation Partnership project,3 gpp), a certain percentage of NACKs are allowed to exist during communication. Therefore, when the base station 100 continuously receives a certain number of ACKs, it indicates that the current channel condition can meet the requirements of the current modulation order and the channel coding rate, and can increase the modulation order and the channel coding rate to obtain a higher transmission rate. When the NACK received by the base station 100 is higher than a certain ratio, for example, 10% specified by 3GPP, it indicates that the current channel condition does not satisfy the requirements of the current modulation order and the channel coding rate. Therefore, the modulation order and the code rate need to be reduced to ensure normal communication between the base station 100 and the user equipment 200.
It can be understood that each message in the communication process between the ue 200 and the base station 100 is CRC-processed, so that the ue 200 and the base station 100 continuously generate feedback messages in the communication process, and each feedback message includes only one ACK or one NACK.
In some embodiments, an ACK/NACK counter is included within the base station 100. The ACK/NACK counter is used to count the number of ACKs and NACKs and adjust an MCS value communicated between the base station 100 and the user equipment 200 according to the number of ACKs and/or NACKs. For example, if the ACKs are consecutive and exceed a certain number, the MCS value is adjusted higher. If the NACK ratio is higher than a predetermined value, the MCS value is reduced.
In some embodiments, the base station 100 may be communicatively connected to a plurality of user equipments 200. It is understood that the ACK/NACK counter can simultaneously record the number of ACKs and NACKs for a plurality of user equipments 200. The base station 100 may provide different modulation orders and code rates to different user equipments 200 according to the data recorded by the ACK/NACK counter.
It can be understood that, in the uplink, the communication framework of the uplink between the base station 100 and the ue 200 is the same as that of the downlink, except that the uplink counter is a CRC counter, the Block error rate (BLER) is counted instead of ACK/NACK, and the remaining steps are consistent with those of the downlink, and are not described herein again.
Fig. 2 is a flowchart of an adaptive link modulation coding method according to an embodiment of the present application. The adaptive link modulation coding method shown in fig. 2 is applied to the adaptive link modulation coding system 10 shown in fig. 1, and includes the following steps:
s100: ACK or NACK information from the UE is acquired.
In some embodiments, the base station 100 obtains feedback information reported by the ue 200, where the feedback information includes ACK or NACK information. The base station 100 includes an ACK/NACK counter, and stores the received ACK or NACK information in the ACK/NACK counter.
In some embodiments, the base station 100 divides the MCS values into different levels, and only increases or decreases the MCS value of one level when performing MCS value adjustment, so as to provide more accurate modulation order and code rate according to channel conditions.
S110: and counting the number of the ACKs and the NACKs.
In some embodiments, the number of ACKs and NACKs in the feedback information is counted by an ACK/NACK counter within the base station 100. Wherein, the ACK and NACK messages in the counter are arranged according to the time sequence received by the counter. The ACK/NACK counter performs data statistics based on the received ACKs and/or NACKs and the corresponding time sequence to perform further MCS value adjustment.
S120: and judging whether the NACK proportion is 0.
In some embodiments, if the ratio of NACK to data counted in the ACK/NACK counter is 0, step S130 is performed. If the NACK ratio is not 0, step S150 is executed.
S130: it is determined whether the consecutive ACKs are above a threshold. Wherein the threshold is a first threshold, and when the number of consecutive ACKs is determined to be higher than the first threshold, step S140 is executed. Otherwise, step S180 is executed.
It is to be understood that, in some embodiments, if the feedback information received in the ACK/NACK counter is consecutive ACKs, it is further determined whether the number of consecutive ACKs is higher than the first threshold. If the number of consecutive ACKs is higher than the first threshold, it indicates that the current channel condition is better and a higher MCS value can be supported, and step S140 is performed.
If the number of consecutive ACKs is not higher than the first threshold, which indicates that it is not yet determined whether the current channel condition can support a higher MCS value, step S180 is performed to continue detecting the communication status between the base station 100 and the user equipment 200.
In some embodiments, the value of the first threshold may be set according to actual needs. For example, the larger the value set by the first threshold value is, the longer time is required to determine that the current channel condition is better, but the accuracy of the channel condition determination may be increased. The smaller the value set by the first threshold is, the faster the value of the MCS can be adjusted, so that the MCS value can be adjusted quickly when the channel quality becomes good.
S140: a higher MCS value is selected and counted again.
In some embodiments, since the current channel condition may support a higher MCS value, the MCS value when the base station 100 communicates with the user equipment 200 is increased by one level, and the count of the ACK/NACK counter is cleared to re-detect the communication state of the base station 100 with the user equipment 200 at the new MCS value.
S150: and judging whether the NCAK proportion is higher than a threshold value. Wherein, the threshold is a second threshold, and when the NCAK ratio is determined to be higher than the second threshold, step S160 is executed. Otherwise, step S170 is performed.
In some embodiments, if the received NCAK ratio in the ACK/NACK counter is not 0, it is further determined whether the NCAK ratio is above a second threshold. If the NCAK ratio is higher than the second threshold, it indicates that the current channel condition is poor and the current MCS value cannot be supported, and step S160 is performed. If the NCAK ratio is not higher than the second threshold, step S170 is performed.
In some embodiments, the second threshold may be set to 10% specified by 3GPP, or may be set according to communication requirements. For example, in some application scenarios where the communication link needs to be stable, the second threshold may be lowered to improve the reliability of the communication link at the expense of a certain data transmission rate.
In some embodiments, the statistical period for determining the NCAK ratio to be higher than the second threshold may be adjusted according to the current channel condition. For example, when the channel condition is stable, the statistical period may be increased; the statistical period may be reduced when the channel condition changes faster.
S160: a lower MCS value is selected and counted again.
In some embodiments, the MCS value may be adjusted down by one level when the base station 100 communicates with the user equipment 200 to guarantee the reliability of the communication link. The base station 100 also clears the ACK and NACK data corresponding to the user equipment in the ACK/NACK counter to re-detect the communication status between the base station 100 and the user equipment 200 at the new MCS value.
S170: the current MCS value is maintained and counted again.
In some embodiments, since the NCAK ratio of the current statistics does not reach the second threshold within one statistics period, it indicates that the current MCS value adapts to the channel condition of the base station 100 and the user equipment 200. Accordingly, the current MCS value is maintained and the value in the ACK/NACK counter is cleared to continue monitoring the communication state of the base station 100 and the user equipment 200.
S180: the current MCS value is maintained and the statistical quantity is continued.
In some embodiments, since the number of the current continuous ACKs is not higher than the first threshold, it is necessary to continue to monitor the communication status of the base station 100 and the user equipment 200 to determine whether the MCS value needs to be adjusted.
It is to be understood that steps S100 to S180 in the adaptive link modulation coding method may also be applied to the downlink. Since the uplink and downlink architectures of the base station 100 when communicating with the user equipment 200 are the same, a more flexible adaptation of the communication channel can be provided. It can be understood that, when the adaptive link modulation coding method is applied to the uplink, the difference is that the uplink counter is a CRC counter, the BLER is counted instead of ACK/NACK, and the remaining steps are consistent with the downlink, which is not described herein again.
It will be appreciated that in some embodiments, the initial value of the MCS may affect the time for the adaptive link modulation coding system 10 to adjust the MCS value to the optimal value. For example, if the convergence difference between the initial value and the final convergence value of the MCS is too large, it takes a long time to converge, and the communication link is always poor in communication capability during convergence. For example, if the initial value is set to the maximum value 28, and the final MCS convergence value is 5 due to poor channel conditions, it takes a long time to converge, and the link is in a situation of poor communication capability or even broken link all the time during the convergence process. Similarly, if the final convergence value is 28 and the initial value is 5, the communication throughput cannot reach the higher interval supported by the link quality until the convergence is reached.
Therefore, the adaptive link modulation coding method provided in the embodiment of the present application introduces an initial MCS value selection mechanism to improve the convergence speed of the adaptive link modulation coding method. Specifically, referring to fig. 3, the adaptive link modulation coding method of the present application at least includes the following steps:
s200: and acquiring an initial Signal-to-Noise Ratio (SNR) of the UE.
S210: and performing LUT table lookup according to the initial SNR to obtain an initial MCS interval.
In some embodiments, the base station 100 has a LUT stored therein. Wherein the LUT is only used for the lookup of the initial value of the MCS. Therefore, the LUT may be configured to look up the LUT in the adaptive link modulation coding method provided in the embodiments of the present application to locate an initial value. The initial value of MCS corresponding to SNR in the LUT may be an interval. The base station 100 may select different initial MCS values according to the current selection policy.
S220: and selecting an initial MCS value according to the MCS selection strategy.
In some embodiments, the initial MCS value is selected according to an MCS selection policy. The MCS selection policy may be set to be conservative, that is, the minimum MCS value in the initial MCS interval is selected to ensure that the communication link is always in the state of a through link. The MCS selection policy may also be set to fast convergence, i.e. selecting an intermediate MCS value within the initial MCS interval to increase the convergence speed of the MCS value calculation.
It is to be understood that, after the initial MCS value is selected, the base station 100 and the user equipment 200 may communicate according to the initial MCS value and perform step S100. After the initial value is selected, the communication is carried out, the convergence speed of the MCS value can be improved, and the communication throughput can reach a higher interval supported by the link quality more quickly.
It is understood that in other embodiments, the adaptive link modulation coding method is not limited to using the method shown in fig. 3 to select the initial MCS value, that is, the initial MCS value may also be selected in other manners to increase the convergence speed of the adaptive link modulation coding method. For example, referring to fig. 4, in other embodiments, the adaptive link modulation coding method further includes at least the following steps:
s201: and acquiring the uplink SNR (UL SNR) of the UE.
In some embodiments, the base station 100 acquires the uplink SNR of the user equipment 200.
S202: the uplink SNR is input to a gaussian filter to obtain an average SNR.
In some embodiments, since each measured SNR reflects only the signal reception of a single transmission, in order to filter the channel variations that are sudden and short-lived and can be recovered in a short time, a zero-mean gaussian filter is used to process the SNR to obtain a smooth SNR value. Therefore, the uplink SNR of the user equipment 200 is input to the gaussian filter to obtain an average SNR.
It is understood that the principle of the gaussian filter is that, assuming that the detected uplink SNR follows a zero-mean gaussian distribution, its Probability Density Function (PDF) can be expressed as:
wherein the content of the first and second substances,
n is the filter averaging window size. Selecting all K SNR values in the (mu-sigma, mu + sigma) interval, calculating the average value of SNR, and calculating the SNR average value averaged Can be expressed as:
wherein the SNR (k) ∈(μ-σ,μ+σ)。
It is understood that the filter averaging window size N is set according to the mobility of the user equipment 200. For example, when the mobility of the ue 200 is high, the filter average window size is reduced to obtain more timely feedback information; when the mobility of the ue 200 is low, the filter averaging window size is increased to obtain more accurate feedback information.
In some embodiments, the average SNR of the obtained SNRs is averaged And carrying out the next operation.
S211: LUT lookup is performed according to the average SNR to obtain an initial MCS interval.
In some embodiments, the input in step S211 is the average SNR obtained in step S202, and the rest of the steps are the same as S210 and are not described herein again.
S221: an initial MCS value is selected here according to MCS selection.
In some embodiments, the selection process in step S221 is the same as that in step S220, and is not described herein again.
It can be understood that selecting the initial MCS value within the initial MCS interval acquired in step S211 may further reduce MCS fluctuation caused by channel jitter for a short time, improving the stability of the AMC system 10.
It can be appreciated that referring again to fig. 3 and 4, in the downlink, the SNR value needs to be obtained due to the introduction of the LUT between the SNR and the MCS. However, the measurement of the SNR value can only be performed by the user equipment 200, and the user equipment 200 can only measure the ulsr (see steps S200 and S201). Whereas in the uplink, the downlink SNR, i.e., SNR, cannot be measured input . For this reason, in the uplink, the adaptive link modulation coding method provided in the embodiments of the present application may further estimate the downlink SNR according to the measured ul SNR in the downlink. The downlink SNR estimate is based on a reasonable assumption of reciprocity (reciprocity) of the uplink and downlink channels of the communication link,and under the condition of not considering the beamforming gain and the digital precoding gain, performing power conversion to obtain and improve the convergence speed of the communication link. Since the MCS value of the present application is adjusted according to the actual channel condition, the error between the estimated downlink SNR and the actual downlink SNR can be ignored.
In some embodiments, after the base station 100 obtains the uplink SNR of the ue 200, the ul SNR may be converted into the downlink SNR (i.e., SNR) according to the uplink and downlink power conversion factor input ). Wherein the SNR input The calculation formula of (c) is as follows:
wherein the SNR UL Is the uplink signal-to-noise ratio (i.e., ulsr).
In some embodiments, the uplink and downlink power conversion factors are set based on reciprocity of uplink and downlink channels of the communication link, and may be selected according to an initial downlink SNR when performing initial BCS value selection. The convergence rate of the MCS value calculation in the downlink of the adaptive link modulation coding method is improved.
In some embodiments, the adaptive link modulation and coding method provided by the present application can adjust MCS when the base station communicates with the user equipment according to positive feedback and negative feedback of a channel, without performing CQI measurement and LUT query, improve link throughput when the user equipment communicates with the base station, and reduce probability of link connection failure.
The programs operating in the base station 100 and the user equipment 200 according to the embodiment of the present invention may be programs (programs that cause a computer to function) that control a Central Processing Unit (CPU) or the like to realize the functions of the above-described embodiments according to an aspect of the present invention. Information processed by these apparatuses is temporarily stored in a Random Access Memory (RAM) during processing thereof, and then stored in various ROMs such as a Read Only Memory (Flash ROM) or Hard Disk Drives (HDD), and Read, corrected, and written by a CPU as necessary.
Note that part of the base station 100 or the user equipment 200 according to the above-described embodiments may be implemented by a computer. In this case, the program for realizing the control function may be recorded in a computer-readable recording medium, and the program recorded in the recording medium may be read into a computer system and executed.
Note that, the "computer system" mentioned here refers to a computer system built in the base station 100 or the user equipment 200, and is a computer system using hardware including an OS, peripheral devices, and the like. The term "computer-readable recording medium" refers to a removable medium such as a flexible disk, a magneto-optical disk, a ROM, and a CD-ROM, and a storage device such as a hard disk incorporated in a computer system.
Also, the "computer-readable recording medium" may include: a medium that dynamically stores a program in a short time such as a communication line when the program is transmitted via a network such as the internet or a communication line such as a telephone line; a medium that stores a program for a fixed time, such as a volatile memory in a computer system serving as a server or a client in this case. The program may be a program for realizing a part of the functions, or may be a program that can realize the functions by being combined with a program recorded in a computer system.
The base station 100 in the above embodiment may be implemented as an aggregate (device group) including a plurality of devices. Each device constituting the device group may have a part or all of the functions or functional blocks of the base station 100 according to the above embodiment. The device group may have all the functions or functional blocks of the base station 100. Further, the user equipment 200 of the above embodiment can also communicate with the base station 100 as an aggregate.
It should be understood by those skilled in the art that the above embodiments are only for illustrating the present application and are not used as limitations of the present application, and that suitable modifications and changes of the above embodiments are within the scope of the claims of the present application as long as they are within the spirit and scope of the present application.
Claims (10)
1. An adaptive link modulation coding method, applied to a user equipment and a base station in a communication system, wherein the user equipment is communicatively connected to the base station, the method comprising:
the base station acquires feedback information from the user equipment;
and the base station adjusts the modulation and coding strategy value of the communication between the base station and the user equipment according to the link modulation and coding adjustment strategy and the feedback information.
2. The adaptive link modulation coding method of claim 1, wherein the feedback information comprises positive feedback or negative feedback, the method further comprising:
the user equipment carries out cyclic redundancy check;
if the user equipment passes the cyclic redundancy check, forward feedback is sent to the base station;
and if the user equipment does not pass the cyclic redundancy check, negative feedback is sent to the base station.
3. The adaptive link modulation coding method of claim 2, wherein the modulation and coding strategy value includes a modulation order and a channel coding rate; the link modulation coding adjustment strategy comprises:
if the feedback information acquired by the base station is forward feedback, the modulation order and the channel coding rate are increased;
and if the feedback information acquired by the base station is negative feedback, reducing the modulation order and the channel coding rate.
4. The adaptive link modulation coding method of claim 3, wherein the method further comprises:
the base station counts the number of the positive feedback and the negative feedback;
and if the forward feedback is continuous and the quantity of the forward feedback is higher than a first threshold value, improving the modulation order and the channel coding rate, and clearing the quantity of the forward feedback and the quantity of the negative feedback.
5. The adaptive link modulation coding method of claim 4, wherein the method further comprises:
and if the ratio of the number of the negative feedback to the number of the positive feedback and the negative feedback is higher than a second threshold, reducing the modulation order and the channel coding rate, and clearing the number of the positive feedback and the negative feedback.
6. The adaptive link modulation coding method of claim 1, wherein the base station comprises a look-up table; the method further comprises the following steps:
the base station acquires an initial signal-to-noise ratio from the user equipment;
the base station performs table lookup according to the initial signal-to-noise ratio and a lookup table to obtain a first modulation and coding strategy value initial interval;
the base station selects a first modulation and coding strategy value in the first modulation and coding strategy value initial interval;
and the base station communicates with the user equipment according to the first modulation and coding strategy value.
7. The adaptive link modulation coding method of claim 1, wherein the method further comprises:
the base station acquires an uplink signal-to-noise ratio from the user equipment;
the base station inputs the uplink signal-to-noise ratio to a Gaussian filter to obtain an average signal-to-noise ratio;
the base station performs table lookup according to the average signal-to-noise ratio and the lookup table to acquire a second modulation and coding strategy value initial interval;
the base station selects a second modulation and coding strategy value in the second modulation and coding strategy value initial interval;
and the base station communicates with the user equipment according to the second modulation and coding strategy value.
8. The method of adaptive link modulation coding according to claim 7, wherein the base station further includes an uplink and downlink power conversion factor, the method further comprising:
the base station converts the uplink signal-to-noise ratio into a downlink signal-to-noise ratio according to the uplink signal-to-noise ratio and the uplink and downlink power conversion factors;
and the base station adjusts the modulation and coding strategy value according to the downlink signal-to-noise ratio.
9. An adaptive link modulation coding system, comprising a base station and a user equipment, wherein the base station is communicatively coupled to the user equipment;
the user equipment is used for sending feedback information to the base station, wherein the feedback information comprises positive feedback and negative feedback;
the base station is configured to perform the adaptive link modulation coding method according to any one of claims 1,3 to 8.
10. A base station communicatively coupled to a user equipment, wherein the base station is configured to perform the adaptive link modulation coding method according to any of claims 1,3 to 8.
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