WO2012171358A1

WO2012171358A1 - Method and apparatus for determining user throughput of cell in lte system

Info

Publication number: WO2012171358A1
Application number: PCT/CN2012/071445
Authority: WO
Inventors: 阮玉峰; 张芳; 顾军
Original assignee: 中兴通讯股份有限公司
Priority date: 2011-06-13
Filing date: 2012-02-22
Publication date: 2012-12-20
Also published as: JP2014518471A; CN102833762A; CN102833762B; JP5970544B2

Abstract

Disclosed in the present invention are a method and apparatus for determining user throughput of a cell in a Long-time Evolved (LTE) system, wherein the method comprises the steps of: obtaining the mapping relationship between Signal-Noise-Ratio(SNR) and throughput of the cell via link simulation; computing average Resource Block(RB) number distributed for each user in the cell according to the bandwidth and frequency multiplexing mode of the LTE system; obtaining Carrier to Interference plus Noise Ratio(CINR) for each user in the cell via network simulation; determining the user throughput of the cell according to the mapping relationship between SNR and throughput of the LTE system, the RB number, and the CINR. By obtaining the mapping relationship between SNR and throughput of the LTE system, the average RB number and the CINR for the user, and determining the throughput of the cell with the obtained parameters, the present invention thus solves the problem related to estimating user throughput distribution of the LTE system in related technologies, thereby achieving the effect of estimating user throughput distribution of the LTE system quickly and correctly.

Description

TECHNICAL FIELD The present invention relates to the field of communications, and in particular to a method and apparatus for determining user throughput of an LTE (Long Term Evolution) system cell. BACKGROUND OF THE INVENTION Nowadays, with the rapid expansion of mobile communication networks, network planning and researchers must constantly think about new network protocols and algorithms, and make forward-looking basic research for network development. On the other hand, it is also necessary to study how to utilize and integrate existing ones. Resources to maximize the performance of the network. In either case, verification and analysis of the new network solution is required. There are generally three methods for network planning and technical research: (1) The analysis method is to conduct a preliminary analysis of the object under study and the network system in question, and to study the object and system according to certain qualifications and reasonable assumptions. Describe, abstract the mathematical analysis model of the research object, and solve the problem by using the mathematical analysis model

(2) The experimental method is to design a reasonable hardware and software configuration environment required by the research, establish a test bed and a laboratory, and implement research on network protocols, network behavior and network performance on a real network. (3) Simulation method, using the network simulation software to establish the simulation model of the network system under study, run the model on the computer, and analyze the output of the operation. However, the first two methods have significant limitations. The validity and accuracy of the analytical method are greatly limited by assumptions. When a system is complex, it is impossible to describe the system in detail with some restrictive assumptions. The limitation of the experimental method is that it is costly, it is difficult to reconfigure or share resources, and it is not flexible to use. The simulation method can largely make up for the shortcomings of the first two methods. The simulation method can design the required network model according to the needs, and understand the various characteristics of the network under different conditions with relatively less time and cost, and obtain rich and effective data of network research. Network simulation undoubtedly provides a convenient and efficient verification and analysis method, so the role of network simulation technology in the design and research of modern communication networks is becoming more and more important. Link-level simulation is mainly to verify the performance of various RTT (Radio Transfers Technology) technology solutions. According to the basic module and related algorithms of the physical layer of the wireless transmission technology, and through appropriate channel modeling, a point-to-point wireless link is established. Through the simulation calculation, the relationship between the basic BER (Bit Error Rate) and the SR (Signal to Noise Ratio) is obtained. Link level emulation and network level The simulation pass is a bridge that establishes interconnections through a series of performance curves. These performance curves show the sub-frame error rate function for the instantaneous channel and instantaneous SR. In link-level simulation, additive white Gaussian noise corresponds to the total Interference and Noise, so the link-level signal-to-noise ratio measurement is equivalent to the system-level CINR (Carrier to Interference and Noise Ratio). Measurement of noise ratio). The LTE system is very flexible and supports FDD (Frequency Division Duplexing) and

TDD (Time Division Duplexing;) Two duplex modes, which support multiple transmission schemes, can perform flexible resource allocation scheduling in time domain, frequency domain and code domain. Based on the flexibility of the LTE system, how to accurately and accurately estimate the cell and user throughput distribution of the LTE system for the actual network environment and the different needs of the operator, so as to implement appropriate network planning to ensure that the network can meet the carrier after the network is built. The quality requirements are very important steps in the network planning process. In view of the fast and accurate estimation of the user throughput distribution of the LTE system in the related art, an effective solution has not been proposed yet. SUMMARY OF THE INVENTION A primary object of the present invention is to provide a method and apparatus for determining user throughput of an LTE system cell, so as to at least solve the problem of how to quickly and accurately estimate the user throughput distribution of the LTE system in the above related art. According to an aspect of the present invention, a user throughput determining method for a cell of an LTE system is provided, including: obtaining a signal to noise ratio and a throughput mapping relationship of a cell by using link simulation; calculating according to a bandwidth and frequency multiplexing manner of the LTE system The number of RBs (Resource Blocks) allocated by each user of the cell; the CINR of each user of the cell obtained through network simulation; determining the user throughput of the cell according to the signal-to-noise ratio and throughput mapping relationship, the number of RBs, and the CINR . Preferably, after determining the user throughput of the cell according to the signal to noise ratio and the throughput mapping relationship, the RB number, and the CINR, the method further includes: determining the cell throughput according to the user throughput of the cell. Preferably, obtaining a signal to noise ratio and a throughput mapping relationship of the cell by using link simulation includes: obtaining a signal to noise ratio and a throughput mapping curve S R-ThpPerRb of the cell by using link simulation. Preferably, calculating the average number of RBs allocated by each user of the cell according to the bandwidth and frequency multiplexing manner of the LTE system includes: calculating the available RB number RbNum of the cell according to the bandwidth and frequency multiplexing manner of the LTE system; calculating each cell according to the RbNum The average number of RBs allocated by the user is RbNumPerUe, where the calculation formula is: RbNumPerUe=RbNum/Nu, where Nu is the number of activated users of the cell. Preferably, obtaining the CINR of each user of the cell by using network simulation includes: spreading M users in the cell, and obtaining a CINR of the user of the cell by network simulation. Preferably, determining the user throughput of the cell according to the signal to noise ratio and the throughput mapping relationship, the RB number, and the CINR includes: searching the S R-ThpPerRb curve according to the CINR of the user, and obtaining the CIR corresponding to the throughput ThpPerRb of each user in each transmission mode. The maximum value ThpPerRbJ; determines the user's throughput ThpJ according to ThpPerRbJ and RbNumPerUe, and the calculation formula is: Thp"=ThpPerRb"*RbNumPerUe. Preferably, the cell throughput includes cell average throughput and/or cell edge throughput. According to another aspect of the present invention, a user throughput determining apparatus for an LTE system cell is provided, including: a first simulation module, configured to obtain a signal to noise ratio and a throughput mapping relationship of a cell through link simulation; The method is configured to calculate, according to the bandwidth and frequency multiplexing manner of the LTE system, the average number of resource blocks RB allocated by each user of the cell; the second simulation module is configured to obtain a carrier interference-to-noise ratio (CINR) of each user of the cell by using network simulation; A determining module is configured to determine a user throughput of the cell according to a signal to noise ratio and a throughput mapping relationship, an RB number, and a CINR. Preferably, the apparatus further comprises: a second determining module, configured to determine a cell throughput according to a user throughput of the cell. Preferably, the cell throughput includes cell average throughput and/or cell edge throughput. According to the present invention, the SNR of the LTE system is obtained by acquiring the signal-to-noise ratio and the throughput mapping relationship of the LTE system, the average number of RBs of the user, and the CINR of the user, and determining the user throughput of the cell by using the acquired parameters. The user throughput distribution is estimated to achieve a fast and accurate estimation of the user throughput distribution of the LTE system. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are set to illustrate,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, In the drawings: FIG. 1 is a method for determining a user throughput according to an embodiment of the present invention; FIG. 2 is a flow chart for estimating a cell and user throughput distribution according to an embodiment of the present invention; FIG. 3 is an SNR according to an embodiment of the present invention. Mapping the graph with throughput; 4 is a user CINR CDF distribution diagram according to an embodiment of the present invention; FIG. 5 is a user throughput CDF distribution according to an embodiment of the present invention; FIG. 6 is a flowchart of cell and user throughput distribution estimation according to Embodiment 2 of the present invention; 7 is a flowchart of cell and user throughput distribution estimation according to Embodiment 3 of the present invention; FIG. 8 is a structural block diagram of a user throughput determining apparatus according to an embodiment of the present invention; FIG. 9 is a user throughput determination according to an embodiment of the present invention. Schematic diagram of the device structure. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the embodiments in the present application and the features in the embodiments may be combined with each other without conflict. FIG. 1 is a method for determining a user throughput according to an embodiment of the present invention. As shown in FIG. 1, the method includes the following steps: Step S102: Obtain a signal to noise ratio and a throughput mapping relationship of a cell by using link simulation. Step S104: Calculate the average number of resource blocks RB allocated by each user of the cell according to the bandwidth and frequency multiplexing manner of the LTE system. Step S106: Obtain a carrier interference-to-noise ratio (CINR) of each user of the cell through network simulation. Step S108: Determine a user throughput of the cell according to a signal to noise ratio and a throughput mapping relationship, an RB number, and a CINR. In this embodiment, by acquiring the signal-to-noise ratio and the throughput mapping relationship of the LTE system, the average number of RBs of the user, and the CINR of the user, and determining the user throughput of the cell according to the acquired parameters, the related art is solved. The problem of estimating the user throughput distribution of the LTE system achieves the effect of quickly and accurately estimating the user throughput distribution of the LTE system. In step S102, the SR and throughput mapping curve S R-ThpPerRb is obtained through link simulation. In step S104, the available RB number RbNum of each cell i is calculated according to the system bandwidth and the frequency multiplexing manner. The average number of RBs per cell RbNumPerUe=RbNum/Nu allocated by the cell i is calculated. Where Nu is the number of active users of the cell i. In step S106, M users (such as M=1000) are sprinkled in each cell i, and the CINR of each user is obtained through network simulation. Wherein, in step S108, the SNR-ThpPerRb curve is searched according to the user CINR value. For user j, the CINR is the maximum value ThpPerRbJ corresponding to ThpPerRb in each transmission mode, and the throughput of user j is Thp" = ThpPerRb" *RbNumPerUe. After step S108, the throughput indicator of the cell i, such as the cell average throughput and the cell edge throughput, is calculated according to the throughput of the user. In the following embodiments, the cell 1 and the 10 active users per cell are taken as an example, and the operation flow of other cells is similar to that of the cell 1. Embodiment 1 In this embodiment, the key parameters are as follows: FDD mode, transmission mode 2, system bandwidth is 15 MHz, co-frequency multiplexing, the number of transmitting antennas is 4, and the number of receiving antennas is 2. 2 is a flowchart of estimating a cell and user throughput distribution according to the first embodiment of the present invention. As shown in FIG. 2, the method includes the following steps: Step S202: Obtain an SR and a throughput mapping curve SNR-ThpPerRb through link simulation.

The SNR-ThpPerRb distribution curve is shown in Figure 3. Step S204, calculating the number of available RBs RbNum per cell. In the same-frequency multiplexing mode, the number of available RBs per cell is the same as the total number of available RBs in the system, and RbNum=75. Step S206, calculating the average number of RBs allocated per user RbNumPerUe, RbNumPerUe=75/10=7.5 Step S208, sprinkling M users (such as M=1000) in each cell i, and obtaining each user through network simulation CINR. The user CINR CDF distribution is shown in Figure 4. Step S210, searching for an SNR-ThpPerRb curve according to the user CINR value. For user j, find the 'Emission Mode 2 (FDD)' curve in FIG. 3 according to its CINR value CINRJ, and obtain its per-RB throughput ThpPerRbJ, then the throughput of user j is Thp"=ThpPerRb"*RbNumPerUe, and the obtained user throughput The quantity distribution is shown in Figure 5. Step S212, calculating a cell average throughput and a cell edge throughput value of the cell 1. The average throughput of the cell is Thp = ThpJ, and the user's throughput value can be reached by the user with a cell edge throughput value of 95%.

The specific values are shown in Table 1. Table 1

Embodiment 2 In this embodiment, the key parameters are as follows: FDD mode, transmission mode 2, 4 adaptive, system bandwidth is 15 MHz, inter-frequency multiplexing, the number of transmitting antennas is 4, and the number of receiving antennas is 2. FIG. 6 is a flowchart of estimating a cell and user throughput distribution according to Embodiment 2 of the present invention. As shown in FIG. 6, the method includes the following steps: Step S602: Obtain an SNR and throughput mapping curve SNR-ThpPerRb through link simulation, such as Figure 3 shows. Step S604: In the same-frequency multiplexing mode, the number of available RBs per cell is the same as the total number of available RBs in the system, and RbNum=75. In step S606, the average number of RBs allocated per user RbNumPerUe=75/10=7.5. Step S608, M users (such as M=1000) are sprinkled in each cell i, and the CINR of each user is obtained through network simulation. The user CINR CDF distribution is shown in Figure 4. Step S610, searching for an SNR-ThpPerRb curve according to the user CINR value. For user j, find the 'transmit mode 2 (FDD)', 'transmit mode 4 single stream (FDD)' and 'transmit mode 4 dual stream (FDD)' curves in Figure 3 according to its CINR value CINRJ, and take the maximum value as The per-RB throughput of the user, ThpPerRbJ, is the throughput of user j, Thp"=ThpPerRb"*RbNumPerUe, and the obtained user throughput distribution is as shown in FIG. Step S612, calculating the cell average throughput and the cell edge throughput value of the cell 1, and the specific values are shown in Table 1. Embodiment 3 In this embodiment, the key parameters are as follows: TDD mode, transmission mode 2, system bandwidth is 15 MHz, co-frequency multiplexing, the number of transmitting antennas is 4, and the number of receiving antennas is 2. FIG. 7 is a flowchart of estimating a cell and user throughput distribution according to Embodiment 3 of the present invention. As shown in FIG. 7, the method includes the following steps: Step S702: Obtain an SNR and throughput mapping curve SNR-ThpPerRb through link simulation, such as Figure 3 shows. Step S704: In the same-frequency multiplexing mode, the number of available RBs per cell is the same as the total number of available RBs in the system, and RbNum=75. In step S706, the average number of RBs allocated per user RbNumPerUe=75/10=7.5. Step S708, M users (such as M=1000) are sprinkled in each cell i, and the CINR of each user is obtained through network simulation. The user CINR CDF distribution is shown in Figure 4. Step S710, searching for an SNR-ThpPerRb curve according to the user CINR value. For user j, look up the 'Transmission Mode 2 (TDD)' curve in Figure 3 based on its CINR value CINRJ, and take the maximum value for each RB throughput ThpPerRb of the user, then the throughput of user j is Thp"=ThpPerRb" *RbNumPerUe, the user throughput distribution obtained is shown in Figure 5. Step S712, calculating the cell average throughput and the cell edge throughput value of the cell 1, and the specific values are shown in Table 1. FIG. 8 is a structural block diagram of a user throughput determining apparatus according to an embodiment of the present invention. As shown in FIG. 8, the apparatus includes: a first simulation module 10, a calculation module 20, a second simulation module 30, and a first determination module 40. The first simulation module 10 is configured to obtain a signal to noise ratio and a throughput mapping relationship of the cell through link simulation. The calculation module 20 is configured to calculate the average number of resource blocks RB allocated by each user of the cell according to the bandwidth and frequency multiplexing manner of the LTE system. The second simulation module 30 is configured to obtain a carrier to interference and noise ratio CINR for each user of the cell through network simulation. The first determining module 40 is configured to determine the user throughput of the cell based on the signal to noise ratio and the throughput mapping relationship, the number of RBs, and the CINR. In this embodiment, by acquiring the signal-to-noise ratio and the throughput mapping relationship of the LTE system, the average number of RBs of the user, and the CINR of the user, and determining the user throughput of the cell according to the acquired parameters, the related art is solved. The problem of estimating the user throughput distribution of the LTE system achieves the effect of quickly and accurately estimating the user throughput distribution of the LTE system. FIG. 9 is a schematic structural diagram of a user throughput determining apparatus according to an embodiment of the present invention. As shown in FIG. 9, the device includes each functional module in the above embodiment: a first simulation module 10, a calculation module 20, a second simulation module 30, and a first determination module 40. The apparatus further includes a second determining module 50 configured to determine a cell throughput based on a user throughput of the cell. Cell throughput includes cell average throughput and cell edge throughput. INDUSTRIAL APPLICABILITY The present invention provides a method and apparatus for determining user throughput of an LTE system cell, which can quickly and accurately estimate the distribution of cell and user throughput under various network configurations, and support different frequency multiplexing modes and transmissions. The solution is applicable to both LTE FDD and TDD duplex modes. Obviously, those skilled in the art should understand that the above modules or steps of the present invention can be implemented by a general-purpose computing device, which can be concentrated on a single computing device or distributed over a network composed of multiple computing devices. Alternatively, they may be implemented by program code executable by the computing device, such that they may be stored in the storage device by the computing device and, in some cases, may be different from the order herein. The steps shown or described are performed, or they are separately fabricated into individual integrated circuit modules, or a plurality of modules or steps are fabricated as a single integrated circuit module. Thus, the invention is not limited to any specific combination of hardware and software. The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Claims

Claim

A method for determining a user throughput of a cell of a long-term evolution LTE system, comprising: obtaining, by using link simulation, a signal-to-noise ratio and a throughput mapping relationship of the cell;

Calculating, according to the bandwidth and frequency multiplexing manner of the LTE system, the average number of resource blocks RB allocated by each user of the cell; obtaining a carrier interference-to-noise ratio CINR of each user of the cell by network simulation;

The user throughput of the cell is determined according to the signal to noise ratio and throughput mapping relationship, the number of RBs, and the CINR.

The method according to claim 1, wherein, after determining the user throughput of the cell according to the signal to noise ratio and the throughput mapping relationship, the number of RBs, and the CINR, the method further includes:

The cell throughput is determined based on user throughput of the cell.

The method according to claim 1, wherein the mapping between the signal to noise ratio and the throughput of the cell is obtained by link simulation:

The signal to noise ratio and throughput mapping curve S R-ThpPerRb of the cell is obtained through link simulation.

The method according to claim 3, wherein calculating the average number of RBs allocated by each user of the cell according to the bandwidth and frequency multiplexing manner of the LTE system includes:

Calculating the available RB number RbNum of the cell according to the bandwidth and frequency multiplexing manner of the LTE system;

Calculating, according to the RbNum, an average number of RBs RbNumPerUe allocated to each user of the cell, where the calculation formula is:

RbNumPerUe=RbNum/Nu, where Nu is the number of active users of the cell.

5. The method according to claim 4, wherein obtaining a CINR of each user of the cell by network simulation comprises:

M users are sprinkled in the cell, and the CINR of the user of the cell is obtained through network simulation.

The method according to claim 5, wherein determining the user throughput of the cell according to the signal to noise ratio and throughput mapping relationship, the number of RBs, and the CINR comprises: Finding the SNR-ThpPerRb curve according to the CINR of the user, and obtaining a maximum value ThpPerRbJ of the CIR corresponding to the throughput ThpPerRb in each transmission mode of the CINR of the user;

The throughput Thp" of the user is determined according to the ThpPerRbJ and the RbNumPerUe, and the calculation formula is: Thp"=ThpPerRb" *RbNumPerUe.

7. The method of claim 2, wherein the cell throughput comprises a cell average throughput and/or a cell edge throughput.

8. The user throughput determining apparatus of the LTE system cell, comprising: a first simulation module, configured to obtain a signal to noise ratio and a throughput mapping relationship of the cell by using link simulation;

a calculation module, configured to calculate, according to the bandwidth and frequency multiplexing manner of the LTE system, an average number of resource blocks RB allocated by each user of the cell;

a second simulation module, configured to obtain, by network simulation, a carrier interference-to-noise ratio (CINR) of each user of the cell;

The first determining module is configured to determine a user throughput of the cell according to the signal to noise ratio and throughput mapping relationship, the number of RBs, and the CINR.

9. The apparatus according to claim 8, further comprising: a second determining module, configured to determine the cell throughput according to a user throughput of the cell.

10. The apparatus of claim 8, wherein the cell throughput comprises a cell average throughput and/or a cell edge throughput.