JP2010081594A - Method, apparatus and communication system for selecting combination of modulation and coding systems - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To disclose a method, an apparatus and a communication system for selecting a suitable combination of modulation and MCS for a communication system. <P>SOLUTION: The method includes: a step for gathering statistics on channel quality parameters in a communication system and obtaining its probability distribution; a step for, in accordance with a scheduled request necessary to be satisfied, deciding an application range of a channel quality parameter necessary to be supported from the probability distribution; a step for, with a scheduled system, deciding M target channel quality parameter values in the application range by a schedule system; and a step for, in accordance with the scheduled request necessary to be satisfied, from all possible combinations of modulation systems and coding systems, selecting M kinds of combinations of modulation and coding systems that achieve the respective requests for the M target channel quality parameter values as a set of combinations of modulation and coding systems that are able to be selected and used. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to wireless communication, and more particularly to a technique for designing and selecting a combination of modulation and coding scheme (MCS) in the communication field.

  In any communication system, the transmission medium may be more or less affected and transmission reliability may be reduced. In order to improve the reliability of transmission, it is necessary to always design modulation / demodulation and channel codec technologies at both ends of transmission and reception, and this point is particularly remarkable in a wireless transmission system. A combination of one type of modulation and coding scheme corresponds to the efficiency of one type of spectrum, but a combination of multiple types of MCS can also correspond to the same spectral efficiency. For example, a combination of quadrature phase shift keying (QPSK) and modulation and coding rate 1/2 convolutional code or turbo code can realize transmission efficiency of 1 bit / symbol. Modulation rank (eg, QPSK, multi-level phase shift keying (M-PSK), 16-level quadrature amplitude modulation (16QAM), multi-level quadrature amplitude modulation (M-QAM), etc.) and / or coding rate (1 / By changing 2, 2/3, 3/4, etc., a combination of multiple types of MCS can be realized. Different MCS combinations can be applied in different transmission environments, for example, channels with good transmission conditions can transmit more information using high spectral efficiency MCS combinations to ensure transmission quality. Therefore, a small amount of information can be transmitted using a combination of MCS with low spectrum efficiency in a channel having poor transmission conditions. Usually, in a communication system, whether the transmission condition is good or bad can be evaluated by a signal interference to noise ratio (SINR). Of course, the quality of the channel quality can be displayed by other indicators or parameters, for example, a parameter for displaying the strength of the signal strength such as the signal-to-noise ratio SNR. To meet certain transmission requirements for a given channel quality, for example, usually as high as possible so that the transmission error rate, eg block error rate (BLER) does not exceed a certain threshold (eg 10%) A combination of MCS with spectral efficiency can be selected. Here, the transmission error rate is not limited to BLER, but may be a parameter representing the performance of a combination of a certain modulation and coding scheme, for example, a bit error rate (BER), a frame error rate (FER), or the like. In the normal case, each MCS combination has a different transmission error rate (eg BLER) at different channel quality parameters (eg SINR), so the curve of the transmission error rate and channel quality parameter for various MCS combinations. A figure (for example, a curve diagram of BLER and SINR) can be acquired.

  A technique for selecting different combinations of MCSs according to different reception channel qualities (for example, reception SINR) and thereby assuring as much as possible the throughput of the communication system is called a self-adaptive MCS selection technique. The change range of the received SINR may be determined by many factors, such as system layout, transmission medium distribution, and changes in system service user status. Taking a cellular mobile radio communication system as an example, a user who is relatively close to the base station has a small radio signal transmission attenuation and a large reception SINR, and a user who is relatively far from the base station has a large signal transmission attenuation and a reception SINR. Becomes smaller. Note that in a multi-base station cellular system with a multifactor of 1, the SINR is slightly lower than the user located at the center of the cell due to the interference of the non-service base station when the user located in the cell margin is affected. Statistically speaking, the magnitude of SINR received by the user can be displayed as a probability distribution, for example, a cumulative density function (CDF, Cumulate Density Function) or a probability density function (PDF, Probability Density Function). From these SINR distribution curves, the SINR change range of the user in the communication system can be almost grasped.

In order to utilize the system capacity as much as possible, the self-adapting MCS selection technique must reflect the conditions of the current transmission channel as accurately as possible, i.e., for example, based on the current received SINR value, e.g. A combination of MCS with as high spectral efficiency as possible that satisfies the BLER requirement should be selected. Of course, in order for the transmitting end to transmit correctly, the receiving end must notify the transmitting end of the selected combination of MCSs in an appropriate manner. Since the transmission of MCS combination information also occupies a transmission channel, it is not possible to install an unlimited number of MCS combinations that the system can support, and many communication standards specify MCS combinations that can support both transmission and reception . For example, Non-Patent Document 1 defines 11 combinations of MCS shown in Table 1 below.

  In view of many sentences and / or patents already published, the spectral efficiency is improved so that the relationship curve between BLER and SINR becomes steeper, that is, BLER becomes smaller when SINR is defined. Many have considered how to design a combination of MCS, where prescribed. For example, non-patent documents 2 to 4 can be referred to. These references are incorporated herein by reference.

IEEE802.16E standard (IEEE P802.16e / D12-Draft IEEE Standard for Local and Metropolitan area Networks-Part 16: Air Interface for Fixed and Mobile Broadband Wireless Access Systems-Amendment for Physical and Medium Access Control Layers for Combined Fixed and Mobile Operation in Licensed Bands, October 2005) Harsini, Lahouti, "Optimized link adaptation for wireless packet communications based on discrete-rate modulation and coding schemes" (Signal Processing Advances in Wireless Communications IEEE 2007 T. Sampei, S. Morinaga, "Symbol rate and modulation level controlled adaptive modulation / TDMA / TDD for personal communication systems" (IEEE VTC 1995) Rohling, Grunheid R, "Adaptive coding and modulation in an OFDM-TDMA communication system" (IEEE VTC 1998)

  However, none of the various conventional self-adaptive MCS selection techniques can ensure that the capacity of the communication system is maximized. Therefore, when the number of MCS combinations is determined, how to start from the viewpoint of system design, select an appropriate MCS combination with the goal of improving system throughput, and maximize system capacity. It is still one problem that we are trying to solve for the time being.

  In view of the problem that the system capacity existing in the conventional communication system cannot be fully utilized, the present invention provides a method, apparatus and / or apparatus for selecting an appropriate MCS combination for the communication system. And to solve the above-mentioned problems existing in the prior art at least partly.

  In order to achieve the above object, according to one aspect of the present invention, a step of statistically obtaining a channel quality parameter in a communication system to obtain a probability distribution of the channel quality parameter, the communication system needs to be satisfied, Determining a coverage of the channel quality parameter that the communication system needs to support from the probability distribution according to a scheduled request, and M target channel quality parameters within the coverage by a scheduled scheme. Depending on the planned requirements that the communication system needs to satisfy, with the steps of determining the value (where M is a natural number and equal to the total number of modulation and coding scheme combinations that the communication system can support) M target channel from all possible modulation and code combinations for the communication system. Selecting as a set of modulation and coding scheme combinations that the communication system can select and use a combination of M types of modulation and coding schemes that respectively achieve the quality parameter value requirement. A method is provided for selecting an appropriate modulation and coding scheme (MCS) combination for the system.

  According to another aspect of the present invention, parameter statistics means for statistics of channel quality parameters in a communication system to obtain a probability distribution of the channel quality parameters, and various schedules that the communication system needs to satisfy. The communication system needs to be supported from the probability distribution according to the request and the storage means for storing the various modulation schemes and code schemes that the communication system can select, and the planned requirements that the communication system needs to satisfy A target parameter value determining means for determining M target channel quality parameter values within the applicable range according to a predetermined method (where M is a natural number). The total number of combinations of modulation and coding schemes that the communication system can support And each of the M target channel quality parameter value requirements from all possible modulation and coding scheme combinations for the communication system, depending on the scheduled requirements that the communication system needs to satisfy. Selecting means for selecting as a set of modulation and coding scheme combinations that the communication system can select and use a combination of M types of modulation and coding schemes to achieve An apparatus for selecting a combination of different modulation and coding schemes is provided.

  According to another aspect of the invention, the apparatus for selecting a combination of modulation and coding schemes suitable for a communication system and the selected to be used when communicating with each other between both transmitting and receiving A communication system is provided that includes a notification device for notifying both transmission and reception in a communication system of a set of combinations of modulation and coding schemes as a combination of modulation and coding schemes of the communication system.

  One advantage of the present invention is that by statistically analyzing the distribution of channel quality parameters (eg SINR, etc.) of the communication system, it is possible to ensure that the total number of MCS combinations suitable for this communication system remains unchanged. To optimize system design and selection (including modulation and / or coding) combinations to maximize system capacity.

  These and other advantages of the present invention will become more apparent from the following detailed description of the best mode for carrying out the invention with reference to the drawings.

The invention can be better understood with reference to the following description taken in conjunction with the drawings in the following parts. In all the drawings, the same or similar parts are indicated by the same or similar reference numerals. The foregoing drawings are included in and constitute a part of this specification, together with the following detailed description, and further illustrate the preferred embodiment of the invention by way of example and to interpret the principles and advantages of the invention. Use for. In drawing:
6 is a flowchart schematically illustrating a method for selecting an appropriate MCS combination for a communication system according to an embodiment of the present invention. An example of a typical probability distribution (displayed in PDF) of received SINR obtained by system simulation is shown. 2 shows an example of a method for dividing a SINR distribution range applicable to a communication system into sections. FIG. 3 is a schematic block diagram illustrating an MCS combination selection apparatus for selecting an appropriate MCS combination for a communication system according to an embodiment of the present invention.

  Those skilled in the art should understand that the elements in the drawings are shown merely for simplicity and clarity and have not necessarily been drawn to scale. For example, the size of certain elements in the drawings may be larger than other elements to help improve understanding of embodiments of the present invention.

  The best mode for carrying out the present invention will be described with reference to the drawings as follows. For clarity and simplicity, not all features of an actual embodiment are described in the specification. However, in the process of developing any of this type of actual implementation to achieve the specific goals of the developer, many decisions specific to the embodiment must be made, for example, the system It should be understood that these restrictions that are relevant to the work are met and that these restrictions may be modified with different embodiments. Although development work can be very complex and time consuming, it should be understood by those skilled in the art who have benefited from the content of this disclosure that this development work is only a routine task.

  Here, it is necessary to explain only the apparatus configuration and / or processing steps that are closely related to the method according to the present invention in order to avoid obscuring the present invention with unnecessary details. Other details not relevant to the present invention have been omitted.

  As described above, within a single communication system, there may be multiple types of MCS combinations that can support both transmission and reception, and by combining different modulation schemes with channel coding schemes with different coding rates, MCS combinations with the same or different spectral efficiencies can be generated.

  FIG. 1 is a flowchart schematically illustrating a method 100 for selecting an appropriate MCS combination for a communication system according to an embodiment of the present invention.

  For convenience of explanation, a signal interference noise ratio (that is, reception SINR, hereinafter sometimes abbreviated as “SINR”) on the reception side of the communication system is used as a parameter indicating channel quality, and a block error rate ( A method for selecting an appropriate MCS combination for a communication system according to an embodiment of the present invention will be described in accordance with an embodiment of the present invention where the transmission request of the system is that the BLER is less than a predetermined threshold (for example, 10%). However, those skilled in the art will appreciate that the present invention is not limited thereto and is applicable to communication systems having other channel quality parameters and / or transmission requirements.

  As shown in FIG. 1, in step S110, a channel quality parameter (that is, received SINR, hereinafter may be abbreviated as “SINR”) in the communication system is statistics, and a probability distribution of the channel quality parameter is obtained.

  What needs to be described here is that the communication system expected by system simulation when the method 100 is applied according to an embodiment of the present invention before actually placing the communication net (eg, when designing the communication system). The SINR probability distribution can be obtained by statistically analyzing the received SINR, and if the communication network is already arranged, the method according to the embodiment of the present invention can be applied to obtain the statistical result of the actual driving test. This means that the SINR probability distribution can be acquired. To reflect the true situation, the received SINRs at different base stations need to be statistics. When performing system simulation, any known simulator and / or simulation technique can be employed to statistic the received SINR. For example, record the signal-to-interference and noise power ratio, ie SINR, for each location point of 10,000 or more different location points in the cell, and statistics the number of SINRs in different value intervals. Get the probability distribution map of SINR.

  FIG. 2 shows an example of a schematic probability distribution (displayed in PDF) of the received SINR obtained by system simulation. In Fig. 2, the abscissa displays the SINR value (unit is dB), and the ordinate displays the probability value, that is, the ordinate of a point in the curve in Fig. 2 is SINR and the abscissa value of this point The probability of having From FIG. 2, it is easily found that the probability distributions at different SINR values are different. In addition, the probability distribution of received SINR may differ to some extent in different net arrangements. Normally, the change range of the received SINR value is very wide. For example, as shown in FIG. 2, the SINR value can change from -15 dB to +30 dB. Further, the probability that the SINR value in the intermediate range (for example, the range of -5 to +20 dB shown in FIG. 2) in this example shown in the figure is relatively high. This is because, for example, individual users in a cellular radio communication system are inevitably covered by a single serving base station, so the change in SINR of the majority of users is not large. For convenience of description, how to select a combination of MCSs for maximizing system capacity will be described below using the SINR distribution diagram shown in FIG. 2 as an example.

  Referring to FIG. 1 again, in step S120, based on the SINR probability distribution chart acquired in step S110, a SINR range to be supported by the communication system to satisfy a request such as a planned coverage rate is determined.

  Specifically, based on the acquired probability distribution map of SINR (for example, the probability distribution diagram shown in FIG. 2), the SINR range supported by the communication system is determined according to an index such as a system coverage rate that needs to be satisfied. Determine. For example, the probability value in the probability distribution diagram shown in FIG. 2 is the highest so that the area of the curve area within the SINR range from the lowest SINR point to the highest SINR point is not smaller than the planned system coverage rate, for example 90%. The lowest and highest SINR points are determined symmetrically on both the left and right sides with respect to the point, i.e., the SINR range is expanded symmetrically. In this way, a SINR range of -5 dB to 20 dB can be obtained based on the SINR probability distribution diagram shown in FIG. Obviously, the person skilled in the art will use other methods as necessary to calculate the lowest SINR point (assuming that the SINR value of this point is represented by X) and the highest SINR point (Y (Assuming that the SINR value at this point is displayed). For example, the SINR range (ie, section [X, Y]) supported by the system can be determined by directly determining the minimum value and maximum value of the channel quality parameter as necessary. This can also be referred to as SINR coverage.

  Then, in step S130, it is assumed that the maximum number of MCS combinations that can be supported by the communication system can be determined based on, for example, system design requirements and system overhead information, and displayed as a natural number M. For simplicity, it is assumed below that a combination of M MCSs are arranged in multiple levels in ascending order of spectral efficiency.

  As shown in FIG. 1, the processing process of the method 100 moves to step S140, and the SINR based on the SINR probability distribution map according to a predetermined scheme according to the number M of MCS combinations determined in step S130. Determine M target SINR values (which are discrete values) within the range. Usually, M is an integer power of 2, for example 8, 16, 32, etc., where M = 16 can be assumed.

  As described in the above, since the change of SINR is not so large, it is conceivable to reflect the change characteristic of SINR value by setting the level of M kinds of MCS combinations as appropriate. To put it simply, a combination of a relatively large number of MCSs can be installed within a high SINR occurrence probability range, and a relatively small number of MCS combinations within a low SINR appearance probability range. Combinations can be installed. That is, when the SINR distribution is not a uniform distribution, the corresponding MCS combination level is designed not to be a uniform distribution, and when the SINR distribution is a uniform distribution, the MCS level is also designed to be a uniform distribution. In this way, the purpose of maximizing the system capacity can be achieved by matching the installation of the MCS combination level with the SINR distribution.

Specifically, in step S140 shown in FIG. 1, for example, according to the method shown in FIG. 3, the section [X, Y], which is the SINR application range, is divided into M-1 sub-sections, for a total of M sections. X ₁ = X, x ₂ ,..., X _{M / 2} , x _{M / 2 + 1} ,..., X _M−1 , x _M = Y are determined. The abscissa value at each end point is the expected target SINR value. That is, as shown in FIG. 3, the section lengths of L, L + Δ, L + 2 * Δ,... Indicated by dotted lines in the lower part of FIG. That is, the end length of each sub-interval is determined in order symmetrically toward the left and right sides, ie, the two target SINR points closest to the center point The distance between (ie, x _{M / 2} and x _{M / 2 + 1} in FIG. 3) (ie, the length of one intermediate sub-interval) is L, and left from these two target SINR points, respectively. The length of the i-th sub-interval to the right is L + i * Δ (where i is a natural number and 1 ≦ i ≦ M / 2). Here, L indicates the interval length of the minimum interval between two target SINR points corresponding to the combination of two adjacent levels of MCS to be selected, and the value is an estimate of the channel quality that the system can actually discriminate. It is determined by the range, and in general, a value of 0.5 dB to 1.5 dB can be selected. Here, it is assumed that a value of 1 dB is taken.

In this way, the following equation (1) can be obtained by the above sectioning method.
By substituting M, L, X, and Y determined as described above into equation (1), the value of Δ can be calculated, and the abscissa values of the end points of the M-1 sub-intervals are further calculated. Can be calculated. The abscissa values at the M end points are M target SINR values that the communication system should have.

  Refer back to FIG. 1 again. In step S150, according to the M target SINR values acquired in step S140, M types of MCSs that achieve the desired target SINR value requirements from all possible modulation scheme and coding scheme combinations for the communication system. Select a combination.

  In this process, all possible combinations of modulation and coding schemes that can be selected by the communication system when the transmission condition to be satisfied by the communication system is that the block error rate BLER is 10% or less as described above. On the other hand, the BLER and SINR curve diagrams of each type of MCS combination are obtained by system simulation, and the SINR value when the BLER is 10% is determined as the SINR value corresponding to this type of MCS combination. To do. Then, M SINR values that are equal to or closest to the M target SINR values acquired in step S140 are found from the determined many SINR values. Due to actual coding / modulation limitations, it is usually not possible to obtain a perfectly matched MCS combination that achieves the target SINR value. It is necessary to select the closest MCS combination. A combination of M types of MCSs corresponding to the found M SINR values is a combination of MCSs selected and used for a desired communication system. By applying these combinations of MCS to a real communication system, the SINR value when reaching the defined BLER is equal to or closest to the target SINR value established above.

  However, if, after system simulation, the SINR corresponding to two or more MCS combinations is found to be equal to or close to a certain target SINR value, the highest spectrum for the two or more MCS combinations is found. The combination of that kind of MCS with efficiency can be selected. Of course, other selection criteria may be used. For example, when selecting, the trend of increasing the modulation rank of the combination of MCSs to be selected (for example, increasing the modulation rank from 2 to 4, 6), etc. Guarantee as much as possible.

  In selecting an appropriate MCS combination from all possible encoding and modulation combinations, various methods known to date can be employed, for example, CTC (Convolutional Turbo Code, Convolutional Turbo Code). (Code) encoding method can adopt a slot method, and LDPC (Low Density Parity-Check Code) encoding method adopts a method of transforming and forming a matrix And so on.

For example, still using the above example, M = 16, the determined SINR range is -5 dB to 20 dB, the minimum SINR interval L is 1 dB, and the above method determines the value of Δ as described above, Then, after 16 target SINR values are determined, 16 types of combinations of MCS adopting the CTC code and QAM modulation shown in Table 2 below can be selected according to the acquired target SINR values.

  In Table 2, each row shows one type of MCS combination, the second column shows the coding rate of the coding scheme in the MCS combination, and the third column shows the modulation rank of the modulation scheme in the MCS combination For example, 2 represents QPSK, 4 represents 16QAM, 6 represents 64QAM, the fourth column represents the overall spectral efficiency of the MCS combination, and the second column value is multiplied by the third column value. The fifth column displays the SINR value (unit: dB) when the MCS combination satisfies the transmission requirement (ie, BLER is 10% or less), and is obtained by simulation as described above. Can do.

  The processing flow of the method 100 according to the embodiment of the invention has been described above using SINR and BLER as examples. However, those skilled in the art are not limited to this, and the principle of the present invention is not limited thereto. It should be understood that appropriate modifications can be made to the process flow. For example, if the number M of the most MCS combinations that the communication system can support is already known or preset, step S130 can be omitted. Further, in step S140, a method different from the segmentation method shown in FIG. 3 (for example, each of the left and right sides is centered on the point where the length of each subinterval satisfies another different relationship and has the highest SINR distribution probability value). M target SINR values within the SINR application range may be obtained according to asymmetrically different sub-intervals, etc.), and SINR can be obtained by appropriately setting the level of the combination of M types of MCS It is only necessary to reflect the change characteristic of the value. In the above, it has been described that the range of distribution is expanded symmetrically around the point having the highest SINR distribution probability value so that the planned condition is satisfied, and the application range of SINR is determined. In the method 100, the SINR coverage does not have to be symmetrical on both sides around the point having the highest SINR distribution probability value. Of course, the method 100 may have other alternative or modified schemes, and each is not listed here.

  FIG. 4 is a schematic block diagram illustrating an MCS combination selection apparatus 400 that selects an appropriate MCS combination for a communication system according to an embodiment of the present invention. The MCS combination selection apparatus 400 can execute the method 100 described with reference to the flowchart shown in FIG.

  As shown in FIG. 4, the MCS combination selection apparatus 400 includes a parameter statistics unit 410, a storage unit 420, a target parameter value determination unit 430, and a selection unit 440. It should be noted that the parameter statistical means 410 can statistically analyze the channel quality parameter in the communication system and obtain the probability distribution of this channel quality parameter, as described in connection with FIG. For the sake of brevity, the specific operation process of the parameter statistical means 410 will not be described in detail. Here, the channel quality parameter may be a received SINR, for example, but may be a parameter that can express other channel quality.

  The storage means 420 contains several requirements that the communication system needs to satisfy, such as the scheduled system coverage rate, transmission conditions such as the maximum allowable transmission error rate (eg, block error rate BLER, etc.), modulation and coding schemes, etc. The maximum allowable combination number M can be stored. These requests may be stored in the storage unit 420 in advance, or may be input from the outside during the use of the MCS combination selection device 400 and stored in the storage unit 420. The storage means 420 may store various modulation schemes and encoding schemes that can be selected by the communication system.

  The target parameter value determination means 430 tries to support the communication system based on the probability distribution of the channel quality parameters from the parameter statistics means 410 depending on some conditions that the communication system needs to satisfy, such as the system coverage rate. The range of channel quality parameters to be determined can be determined and set in advance by a method that can be preset (for example, as described above by combining the segmentation methods shown in FIG. 3). Target parameter values can be determined.

  The selection means 440 determines all possible modulation schemes for the communication system based on the M target parameter values determined by the target parameter value determination means 430 in response to requests such as transmission conditions to be satisfied by the communication system. The combination of M and MCS that achieves the desired target parameter value requirement can be selected from the combinations of encoding methods.

  The parameter statistics means 410, the target parameter value determination means 430, and the selection means 440 can perform corresponding operations or processes as described with reference to FIGS. 1 to 3 above, and thus avoid unnecessary repetition. Further, the specific operations or processes are not described in detail here.

  After selecting the appropriate MCS combination for the communication system, it can be notified to both transmission and reception in the communication system and then used in communication transmission with each other.

  In another embodiment of the present disclosure, the MCS combination selection device 400 shown in FIG. 4 can be appropriately improved. For example, the storage means 420 stores in advance several combinations of MCS that can be used in a normal situation, and depending on the probability distribution of the channel quality parameters obtained in the statistical analysis of the communication system, from among this, A combination of M types of MCS suitable for the communication system can be selected, and this can be notified to various parts of the system as a combination of MCSs currently available for this system.

  The method and apparatus for selecting an appropriate combination of MCS for a communication system according to the present disclosure by combining specific embodiments with SINR and BLER as examples have been described. It is not limited to the specific embodiments described, and one of ordinary skill in the art can make some modifications or changes to the method steps or the structure of the apparatus as fully practical.

  Although the method and apparatus according to the embodiments of the present disclosure have been described above in a communication system environment in which modulation and coding scheme selection is performed in a self-adaptive manner, those skilled in the art will understand that the present disclosure similarly describes modulation and coding scheme. It should be understood that the present invention can be applied to a non-self-adaptive selecting communication system.

  Throughout the above description, in a communication system using a method according to an embodiment of the present disclosure and / or including an apparatus according to an embodiment of the present disclosure, a statistical analysis of the channel quality parameters of the system, eg, the design of a combination of MCS from the distribution of SINR Select a relatively high number of MCS combinations in areas where the channel quality parameter distribution probability values are relatively high, and relatively low areas where the channel quality parameter distribution probability values are relatively low. Maximize system capacity by setting MCS combinations and ensuring that the total number of MCS combinations does not change, and appropriately changing the modulation and / or coding method in the MCS combinations. Can do.

  Note that the method and / or apparatus for selecting an MCS combination according to an embodiment of the present disclosure can be used to determine the MCS combinations that the system needs to support when designing a communication system, or the arrangement of communication systems. The existing MCS combinations can be modified and / or updated and used as the system changes to utilize the system capacity as much as possible.

  It should be noted that each operation process of the method according to the present disclosure may be realized by a computer-executable program stored in a storage medium readable by various devices.

  Another object of the present disclosure is to provide a storage medium storing the executable program code directly or indirectly to a system or facility, and a computer or central processing unit ( The program code may be read and executed by a CPU).

  At this time, as long as this system or facility has a function of executing a program, the embodiment of the present disclosure is not limited to the program, and the program is executed by an arbitrary format such as an object program or an interpreter. Or a scenario program provided to the OS.

  The storage media readable by these devices include various memories and storage means, semiconductor equipment, disk devices such as optical, magnetic and magneto-optical disks, and other media suitable for storing information. It is not limited.

  Note that the present disclosure can also be realized by connecting the computer to a corresponding website on the Internet, and downloading the program code of the computer according to the present disclosure and installing it on the computer before executing the program.

  The present disclosure, as one advantage, is conventional for how to design or select an appropriate MCS combination for a communication system according to the many requirements that the communication system needs to satisfy. It offers design or selection concepts that are superior to various MCS design or selection methods.

  The present disclosure, as yet another advantage, is that the method and / or apparatus according to the present disclosure can be used during the initial design of a communication system and can also be used when the arrangement of the communication system changes.

  The present disclosure, as yet another advantage, not only applies to communication systems in which the method and / or apparatus according to the present disclosure uses a self-adaptive MCS selection method, but also uses a non-self-adaptive MCS selection method. It can also be applied to a communication system.

  Finally, what needs to be explained is that the terms "include", "have" or any other variant are meant to cover the inclusion of non-exclusiveness, thereby including a sequence of elements, methods, An article or facility not only includes these elements, but also includes other elements not explicitly shown, or includes elements unique to this type of process, method, article or facility. In the absence of further restrictions, an element defined by “including” in the sentence does not exclude the presence of another identical element in the process, method, article, or facility that includes the element.

  While the embodiments of the present disclosure have been described in detail with reference to the drawings, the embodiments described above are merely used to explain the present disclosure and do not constitute a limitation of the present disclosure. It should be. For those skilled in the art, various modifications and changes can be made to the embodiment without departing from the spirit and scope of the present invention. As such, the scope of the present invention is limited only by the appended claims and their equivalent implications.

The following supplementary notes are described with respect to the above embodiments and examples.
(Appendix 1) Statistics of channel quality parameters in a communication system to obtain a probability distribution of the channel quality parameters;
Determining the coverage of the channel quality parameter that the communication system needs to support from the probability distribution in response to a scheduled request that the communication system needs to satisfy;
Determining M target channel quality parameter values within the applicable range according to a scheduled scheme (where M is a natural number and equal to the total number of modulation and coding scheme combinations that the communication system can support). When,
M types to achieve M target channel quality parameter value requirements out of all possible modulation and coding scheme combinations for the communication system according to the planned requirements that the communication system needs to satisfy Selecting a combination of modulation and coding schemes as a set of modulation and coding scheme combinations that can be selected and used by the communication system;
Selecting a combination of modulation and coding schemes suitable for a communication system.
(Supplementary Note 2) The step of determining the application range of the channel quality parameter is as follows:
Expand the distribution range of the channel quality parameter from the point having the highest probability value in the probability distribution so as to satisfy the predetermined condition, and make the distribution range of the channel quality parameter at this time the application range. The method according to appendix 1, further comprising:
(Supplementary Note 3) Centering on the point having the highest probability value in the probability distribution, the channel quality parameter distribution range is expanded symmetrically toward the outside, and the area of the curved region within the distribution range of the probability distribution is increased. The method according to appendix 2, wherein the communication coverage is set to be equal to or higher than a system coverage rate that the communication system needs to satisfy, and the distribution range of the channel quality parameter at this time is the application range.
(Supplementary Note 4) The step of determining the M target channel quality parameter values includes:
The number of combinations of modulation and coding schemes installed in areas with high distribution probability values of channel quality parameters increases, and the number of combinations of modulation and coding schemes installed in areas with low distribution probability values of channel quality parameters Divide the applicable range of the channel quality parameter into M-1 sections according to a scheduled scheme,
The method of claim 1, further comprising: determining channel quality parameter values at end points of the M-1 intervals as the M target channel quality parameter values.
(Supplementary Note 5) The step of determining the application range of the channel quality parameter includes:
Centering on the point having the highest probability value in the probability distribution, the channel quality parameter distribution range is expanded symmetrically toward the outside, and the area of the curved region within the distribution range of the probability distribution satisfies the communication system. Over the system coverage rate that needs to be set, and the distribution range of the channel quality parameter at this time is the application range,
Here, in the step of determining the M target channel quality parameter values, the following method:
Centering on the point having the highest probability value in the probability distribution, the intermediate section having the length L of the section is determined in the middle of the application range, and outward from the two end points of the intermediate section. Sequentially determine the i-th interval whose interval length is L + i * Δ (where i is a natural number and 1 ≦ i ≦ M / 2, L is a positive number), thereby Dividing the scope of application into M-1 sections,
Assuming that the coverage of the channel quality parameter is displayed in X to Y, the following equation (1):
And the channel quality parameter value of the end point of the M-1 intervals is calculated as the M target channel quality parameter values based on the calculated Δ value.
The method according to claim 4, further comprising: partitioning a range of application of the channel quality parameter into sections to determine the target channel quality parameter value.
(Supplementary note 6) The method according to supplementary note 5, wherein the value of L is selected based on a range of channel quality parameters that the communication system can distinguish.
(Supplementary note 7) The step of selecting a combination of the M types of modulation and encoding methods,
For each possible combination of modulation and coding schemes, for each possible combination of modulation and coding schemes, the system simulation gives the channel quality parameter values for achieving the expected transmission requirements when the combination is applied in the communication system. Confirm the channel quality parameter value corresponding to the combination of types,
From all possible modulation and coding scheme combinations, select the M combinations with the corresponding channel quality parameter values equal to or closest to the M target channel quality parameter values, respectively, and the selected M types The method of claim 1, further comprising: a combination of M modulation and coding schemes that achieve the requirement of the M target channel quality parameter values.
(Supplementary note 8) The method according to supplementary note 7, wherein the scheduled transmission request has a transmission error rate equal to or less than a scheduled threshold value.
(Supplementary note 9) The method according to supplementary note 8, wherein the transmission error rate is a block error rate BLER, a bit error rate BER, or a frame error rate FER.
(Supplementary Note 10) A combination of a plurality of common modulation and coding schemes is stored in advance, and the stored regular modulation and coding in the step of selecting a combination of the M modulation and coding schemes 8. The method of appendix 7, wherein a combination of modulation and coding schemes that achieves the requirement for M target channel quality parameter values preferentially from the scheme combinations is selected.
(Supplementary note 11) The method according to any one of supplementary notes 1 to 10, wherein the method is executed when a communication system is designed, and statistical data of a channel quality parameter of the communication system is acquired by a system simulation in the statistical step. .
(Supplementary note 12) Any one of Supplementary notes 1 to 10, wherein the method is executed when the communication system is already arranged, and the statistical data of the channel quality parameter of the communication system is obtained by an actual operation test in the statistical step. The method described in 1.
(Supplementary note 13) The method according to any one of supplementary notes 1 to 10, wherein the channel quality parameter is a signal interference noise ratio SINR or a signal noise ratio SNR on a reception side in a communication system.
(Supplementary note 14) The method according to any one of supplementary notes 1 to 10, wherein M is an integer power of 2.
(Supplementary Note 15) For a communication system that selects a modulation and coding scheme by self-adaptation or a communication system that selects a modulation and coding scheme by non-self-adaptation, an appropriate combination of modulation and coding scheme is selected. 11. The method according to any one of appendices 1 to 10, which can be applied.
(Supplementary Note 16) Parameter statistical means for statistically obtaining channel quality parameters in a communication system and obtaining a probability distribution of the channel quality parameters;
Storage means for storing various scheduled requests that the communication system needs to satisfy, and various modulation and coding schemes that the communication system can select;
In response to a scheduled request that the communication system needs to satisfy, a coverage of the channel quality parameter that the communication system needs to support is determined from the probability distribution, and within the coverage by a scheduled method Target parameter value determining means for determining M target channel quality parameter values (where M is a natural number and equal to the total number of modulation and coding scheme combinations that the communication system can support);
Depending on the planned demands that the communication system needs to satisfy, there are M kinds of M target channel quality parameter value requirements, respectively, from all possible modulation and coding scheme combinations for the communication system. Selecting means for selecting a combination of modulation and coding schemes as a set of combinations of modulation and coding schemes that can be selected and used by the communication system;
An apparatus for selecting a combination of modulation and coding schemes suitable for a communication system.
(Supplementary Note 17) The target parameter value determining means expands the distribution range of the channel quality parameter outward from the point having the highest probability value in the probability distribution so as to satisfy a predetermined condition, and at this time Item 17. The apparatus according to item 16, wherein a distribution range of channel quality parameters is established within the application range.
(Supplementary note 18) The target parameter value determination means expands a channel quality parameter distribution range symmetrically outwardly around a point having the highest probability value in the probability distribution, and includes within the distribution range of the probability distribution. 18. The apparatus according to appendix 17, wherein the area of the curved region in the system is set to be equal to or higher than a system coverage rate that the communication system needs to satisfy and the distribution range of the channel quality parameter at this time is determined as the applicable range.
(Supplementary note 19) The target parameter value determining means is the following method:
The number of combinations of modulation and coding schemes installed in areas with high channel quality parameter distribution probability values, and the number of modulation and coding scheme combinations installed in areas with low channel quality parameter distribution probability values Divide the applicable range of the channel quality parameter into M-1 sections according to a scheduled scheme,
Determine the channel quality parameter values at the end points of the M-1 intervals as the M target channel quality parameter values;
The apparatus of claim 16, wherein the M target channel quality parameter values are determined by
(Supplementary note 20) The target parameter value determining means expands the distribution range of the channel quality parameter symmetrically toward the outside around the point having the highest probability value in the probability distribution, and the distribution of the probability distribution The area of the curved region within the range is set to be equal to or higher than the system coverage rate that the communication system needs to satisfy, and the distribution range of the channel quality parameter at this time is determined within the applicable range. method:
Centering on the point having the highest probability value in the probability distribution, the intermediate section having the length L of the section is determined in the middle of the application range, and outward from the two end points of the intermediate section. Sequentially determine the i-th interval whose interval length is L + i * Δ (where i is a natural number and 1 ≦ i ≦ M / 2, L is a positive number), thereby Dividing the scope of application into M-1 sections,
Assuming that the coverage of the channel quality parameter is displayed in X to Y, the following equation (1):
And the channel quality parameter value of the end point of the M-1 intervals is calculated as the M target channel quality parameter values based on the calculated Δ value.
20. The apparatus according to appendix 19, wherein the target channel quality parameter value is determined by dividing an application range of the channel quality parameter into sections.
(Supplementary note 21) The apparatus according to supplementary note 20, wherein the value of L is selected based on a range of channel quality parameters that the communication system can distinguish.
(Additional remark 22) The said selection means is the following system:
For each combination of all possible modulation and coding scheme combinations, the system simulation determines the channel quality parameter value at which the expected transmission requirements are achieved when this type combination is applied in a communication system. , Confirm the channel quality parameter value corresponding to this kind of combination,
From all possible modulation and coding scheme combinations, select the M combinations with the corresponding channel quality parameter values equal to or closest to the M target channel quality parameter values, respectively, and the selected M types A combination of M modulation and coding schemes that achieve the requirements of the M target channel quality parameter values,
17. The apparatus according to appendix 16, wherein a combination of the M kinds of modulation and encoding schemes is selected by:
(Supplementary note 23) The device according to supplementary note 22, wherein the scheduled transmission request has a transmission error rate equal to or less than a scheduled threshold value.
(Supplementary note 24) The apparatus according to supplementary note 23, wherein the transmission error rate is a block error rate BLER, a bit error rate BER, or a frame error rate FER.
(Supplementary Note 25) A plurality of combinations of common modulation and coding schemes are stored in the storage means in advance, and the selection means preferentially selects M from the stored combinations of regular modulation and coding schemes. Item 23. The apparatus of item 22, wherein a combination of modulation and coding schemes that achieves the desired target channel quality parameter value requirement is selected.
(Supplementary note 26) The device according to any one of supplementary notes 16 to 25, wherein the apparatus is used when designing a communication system, and the parameter statistical means obtains statistical data of channel quality parameters of the communication system by system simulation. apparatus.
(Supplementary note 27) Any one of Supplementary notes 16 to 25, wherein the apparatus is used when a communication system is already installed, and the parameter statistical means obtains statistical data of a channel quality parameter of the communication system through a practical operation test. The apparatus according to item 1.
(Supplementary note 28) The apparatus according to any one of supplementary notes 16 to 25, wherein the channel quality parameter is a signal interference noise ratio SINR or a signal noise ratio SNR on a reception side in a communication system.
(Supplementary note 29) The apparatus according to any one of supplementary notes 16 to 25, wherein M is an integer power of 2.
(Supplementary Note 30) For a communication system that selects a modulation and coding scheme by self-adaptation or a communication system that selects a modulation and coding scheme by non-self-adaptation, an appropriate combination of modulation and coding scheme is selected. The apparatus according to any one of appendices 16 to 25, which can be applied.
(Supplementary note 31) The apparatus according to any one of supplementary notes 16 to 29, which selects a combination of modulation and coding schemes suitable for a communication system;
The set of combinations of the selected modulation and coding scheme is notified to both transmission and reception in the communication system as a combination of modulation and coding scheme of the communication system, and used when communicating with each other between both transmission and reception A communication device.
(Supplementary note 32) The communication system according to supplementary note 31, wherein the communication system is a communication system that selects a modulation and coding scheme in a self-adaptive manner, or a communication system that selects a modulation and coding scheme in a non-self-adaptive manner.

400 MCS Combination Selection Device 410 Parameter Statistics Unit 420 Storage Unit 430 Target Parameter Value Determination Unit 440 Selection Unit

Claims (13)

Statistics a channel quality parameter in the communication system to obtain a probability distribution of the channel quality parameter;
Determining the coverage of the channel quality parameter that the communication system needs to support from the probability distribution in response to a scheduled request that the communication system needs to satisfy;
Determining M target channel quality parameter values within the applicable range according to a scheduled scheme (where M is a natural number and equal to the total number of modulation and coding scheme combinations that the communication system can support). When,
M types to achieve M target channel quality parameter value requirements out of all possible modulation and coding scheme combinations for the communication system according to the planned requirements that the communication system needs to satisfy Selecting a combination of modulation and coding schemes as a set of modulation and coding scheme combinations that can be selected and used by the communication system;
Selecting a combination of modulation and coding schemes suitable for a communication system. Determining the coverage of the channel quality parameter comprises:
Expand the distribution range of the channel quality parameter from the point having the highest probability value in the probability distribution so as to satisfy the predetermined condition, and make the distribution range of the channel quality parameter at this time the application range. The method of claim 1, further comprising:   Centering on the point having the highest probability value in the probability distribution, the channel quality parameter distribution range is expanded symmetrically toward the outside, and the area of the curved region within the distribution range of the probability distribution is satisfied by the communication system. 3. The method according to claim 2, wherein the coverage is equal to or higher than a system coverage rate that needs to be performed, and a distribution range of channel quality parameters at this time is set as the applicable range. Determining the M target channel quality parameter values comprises:
The number of combinations of modulation and coding schemes installed in areas with high distribution probability values of channel quality parameters increases, and the number of combinations of modulation and coding schemes installed in areas with low distribution probability values of channel quality parameters Divide the applicable range of the channel quality parameter into M-1 sections according to a scheduled scheme,
2. The method of claim 1, further comprising: determining channel quality parameter values at end points of the M-1 intervals as the M target channel quality parameter values. Determining the coverage of the channel quality parameter comprises:
Centering on the point having the highest probability value in the probability distribution, the channel quality parameter distribution range is expanded symmetrically toward the outside, and the area of the curved region within the distribution range of the probability distribution satisfies the communication system. Over the system coverage rate that needs to be set, and the distribution range of the channel quality parameter at this time is the application range,
Here, in the step of determining the M target channel quality parameter values, the following method:
Centered on the point having the highest probability value in the probability distribution, the intermediate section having the length L of the section is determined in the middle of the application range, and outward from the two end points of the intermediate section. Sequentially determine the i-th interval whose interval length is L + i * Δ (where i is a natural number and 1 ≦ i ≦ M / 2, L is a positive number), thereby Dividing the scope of application into M-1 sections,
Assuming that the coverage of the channel quality parameter is displayed in X to Y, the following equation (1):
And the channel quality parameter value of the end point of the M-1 intervals is calculated as the M target channel quality parameter values based on the calculated Δ value.
5. The method of claim 4, further comprising: partitioning the coverage of the channel quality parameter into sections and determining the target channel quality parameter value. The step of selecting a combination of the M kinds of modulation and coding schemes,
For each possible combination of modulation and coding schemes, for each possible combination of modulation and coding schemes, the system simulation gives the channel quality parameter values for achieving the expected transmission requirements when the combination is applied in the communication system. Confirm the channel quality parameter value corresponding to the combination of types,
From all possible modulation and coding scheme combinations, select the M combinations with the corresponding channel quality parameter values equal to or closest to the M target channel quality parameter values, respectively, and the selected M types 2. The method of claim 1, further comprising: a combination of M modulation and coding schemes that achieves the requirement of the M target channel quality parameter values. A parameter statistical means for statistically obtaining channel quality parameters in the communication system and obtaining a probability distribution of the channel quality parameters;
Storage means for storing various scheduled requests that the communication system needs to satisfy, and various modulation and coding schemes that the communication system can select;
In response to a scheduled request that the communication system needs to satisfy, a coverage of the channel quality parameter that the communication system needs to support is determined from the probability distribution, and within the coverage by a scheduled method Target parameter value determining means for determining M target channel quality parameter values (where M is a natural number and equal to the total number of modulation and coding scheme combinations that the communication system can support);
Depending on the planned demands that the communication system needs to satisfy, there are M kinds of M target channel quality parameter value requirements, respectively, from all possible modulation and coding scheme combinations for the communication system. Selecting means for selecting a combination of modulation and coding schemes as a set of combinations of modulation and coding schemes that can be selected and used by the communication system;
An apparatus for selecting a combination of modulation and coding schemes suitable for a communication system.   The target parameter value determining means expands the distribution range of the channel quality parameter outward from the point having the highest probability value in the probability distribution so as to satisfy a predetermined condition, and the channel quality parameter at this time The apparatus according to claim 7, wherein a distribution range is established at the application range.   The target parameter value determining means expands the distribution range of the channel quality parameter symmetrically outwardly around the point having the highest probability value in the probability distribution, and sets the curve region within the distribution range of the probability distribution. The apparatus according to claim 8, wherein the area is set to be equal to or higher than a system coverage rate that the communication system needs to satisfy, and a distribution range of channel quality parameters at this time is determined as the application range. The target parameter value determination means has the following method:
The number of combinations of modulation and coding schemes installed in areas with high channel quality parameter distribution probability values, and the number of modulation and coding scheme combinations installed in areas with low channel quality parameter distribution probability values Divide the applicable range of the channel quality parameter into M-1 sections according to a scheduled scheme,
Determine the channel quality parameter values at the end points of the M-1 intervals as the M target channel quality parameter values;
8. The apparatus of claim 7, wherein the M target channel quality parameter values are determined by The target parameter value determination means expands the distribution range of the channel quality parameter symmetrically toward the outside around the point having the highest probability value in the probability distribution, and curves within the distribution range of the probability distribution The area of the region is set to be equal to or higher than the system coverage rate that the communication system needs to satisfy, and the distribution range of the channel quality parameter at this time is determined within the applicable range, and the target parameter value determining means is configured as follows:
Centered on the point having the highest probability value in the probability distribution, the intermediate section having the length L of the section is determined in the middle of the application range, and outward from the two end points of the intermediate section. Sequentially determine the i-th interval whose interval length is L + i * Δ (where i is a natural number and 1 ≦ i ≦ M / 2, L is a positive number), thereby Dividing the scope of application into M-1 sections,
Assuming that the coverage of the channel quality parameter is displayed in X to Y, the following equation (1):
And the channel quality parameter value of the end point of the M-1 intervals is calculated as the M target channel quality parameter values based on the calculated Δ value.
The apparatus of claim 10, wherein the target channel quality parameter value is determined by dividing an application range of the channel quality parameter into sections. The selection means has the following scheme:
For each combination of all possible modulation and coding scheme combinations, the system simulation determines the channel quality parameter value at which the expected transmission requirements are achieved when this type combination is applied in a communication system. , Confirm the channel quality parameter value corresponding to this kind of combination,
From all possible modulation and coding scheme combinations, select the M combinations with the corresponding channel quality parameter values equal to or closest to the M target channel quality parameter values, respectively, and the selected M types A combination of M modulation and coding schemes that achieve the requirements of the M target channel quality parameter values,
The apparatus according to claim 7, wherein a combination of the M kinds of modulation and coding schemes is selected by: 13. Apparatus according to any one of claims 7 to 12 for selecting a suitable combination of modulation and coding scheme for a communication system;
The set of combinations of the selected modulation and coding scheme is notified to both transmission and reception in the communication system as a combination of modulation and coding scheme of the communication system, and used when communicating with each other between both transmission and reception A communication device.