CN111245557A - Method, device and equipment for improving downlink efficiency of LTE network - Google Patents

Abstract

Embodiments of the present invention provide a method, apparatus, and device for improving downlink efficiency of an LTE network, including: adjusting the transmission density of cell-specific reference signals in downlink signals in a service area according to a scenario type of a service area, where the scenario types include high-speed scenarios, medium-low speed scenarios Scenarios, slow and stationary scenarios, and mixed scenarios; transmit cell-specific reference signals to each terminal within the service area according to the adjusted transmit density. The method, device and device of the present invention adjust the transmission density of the cell-specific reference signal in the downlink signal in the service area according to the scene type. For medium and low-speed scenarios, slow-speed and static scenarios, the transmission density can be adjusted to be far lower than the currently specified 4 times/ms can reduce the occupancy of cell-specific reference signals in the downlink signal, so that the downlink signal can use more resources to transmit the user's communication data service, thereby improving the downlink efficiency of the LTE network.

Description

A method, apparatus and device for improving downlink efficiency of LTE network

technical field

Embodiments of the present invention relate to the field of communication technologies, and more particularly, to a method, apparatus, and device for improving downlink efficiency of an LTE network.

Background technique

The purpose of cell-specific reference signals (CRS) in the LTE network is not to carry user data, but to provide a technical means for the terminal to estimate the downlink channel; the terminal can use the cell-specific reference signal to Transmission information such as downlink signal strength information, quality information, and synchronization information is obtained, and the cell-specific reference signal is equivalent to a pilot signal.

In each cell, for 1, 2 or 4 antenna ports, there are 1, 2 or 4 cell-specific reference signals, respectively. For a cell that supports PDSCH transmission, all its downlink subframes (including special subframes) shall transmit cell-specific reference signals. These reference signals can be in port 0 or port 0, 1 or port 0, 1, 2, 3 The transmission corresponds to the single transmit antenna cell or the double transmit antenna cell or the four transmit antenna cell of the actual base station, respectively. The larger the number of antennas in a cell, the stronger the spatial multiplexing capability, and the larger the bandwidth of the cell; in order to characterize the propagation characteristics of different antennas, the correspondingly more CRSs are occupied.

The LTE network specifies a very high transmission density for cell-specific reference signals, 4 times per subframe, that is, 4 times/ms. The extremely high pilot frequency transmission density can compensate for the Doppler frequency shift at high speed. Influence, to achieve the communication requirements of the LTE network at a high speed of up to 350Km/h, this is to meet the high-speed communication requirements of the current high-speed rail. The REs of the cell-specific reference signals cannot carry data services. Therefore, for most cells serving stationary or low-to-medium-speed terminals, too many cell-specific reference signals in the downlink signal occupy too many downlink resources, resulting in valuable downlink resources. The waste of wireless RE resources affects the downlink efficiency of the LTE network.

SUMMARY OF THE INVENTION

In order to overcome the above problems or at least partially solve the above problems, embodiments of the present invention provide a method, apparatus and device for improving downlink efficiency of an LTE network.

According to a first aspect of the embodiments of the present invention, there is provided a method for improving downlink efficiency of an LTE network, including: adjusting the transmission density of cell-specific reference signals in downlink signals in the service area according to the scene type of the service area, where the scene types include high-speed scene, Medium and low speed scenarios, slow and stationary scenarios, and mixed scenarios; transmit cell-specific reference signals to each terminal in the service area according to the adjusted transmission density.

According to a second aspect of the embodiments of the present invention, there is provided an apparatus for improving downlink efficiency of an LTE network, including: an adjustment module configured to adjust the transmission density of cell-specific reference signals in downlink signals in the service area according to the scene type of the service area, the scene Types include high-speed scenarios, medium-low speed scenarios, slow-speed and static scenarios, and mixed scenarios; the transmitting module is used to transmit cell-specific reference signals to each terminal in the service area according to the adjusted transmission density.

According to a third aspect of the embodiments of the present invention, an electronic device is provided, including: at least one processor, at least one memory, and a data bus; wherein: the processor and the memory communicate with each other through the data bus; Program instructions executed by the processor, where the processor invokes the program instructions to execute the method for improving downlink efficiency of an LTE network provided by any one of the possible implementation manners of the first aspect.

According to a fourth aspect of the embodiments of the present invention, a non-transitory computer-readable storage medium is provided, the non-transitory computer-readable storage medium stores a computer program, and the computer program causes a computer to execute various possible implementations of the first aspect The method for improving the downlink efficiency of the LTE network provided by any of the possible implementation manners.

A method, device, and device for improving downlink efficiency of an LTE network provided by the embodiments of the present invention include: adjusting the transmission density of cell-specific reference signals in downlink signals in the service area according to the scene type of the service area, and the scene types include high-speed Low-speed scenarios, slow-speed and stationary scenarios, and mixed scenarios; cell-specific reference signals are transmitted to each terminal in the service area according to the adjusted transmission density. The method, device and device of the present invention adjust the transmission density of the cell-specific reference signal in the downlink signal in the service area according to the type of the scene. For the medium and low speed scene, the slow speed and the static scene, the transmission density can be adjusted to be far lower than the current regulation. 4 times/ms can reduce the occupation of cell-specific reference signals in the downlink signal, so that the downlink signal can use more resources to transmit the user's communication data service, thereby improving the downlink efficiency of the LTE network.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts.

1 is a flowchart of a method for improving downlink efficiency of an LTE network provided according to an embodiment of the present invention;

2 is a map of RE locations of cell-specific reference signals transmitted at a transmission density of 4 times/ms according to an embodiment of the present invention;

3 is a map of RE locations of cell-specific reference signals transmitted with a transmission density of 2 times/ms according to an embodiment of the present invention;

4 is a map of RE locations of cell-specific reference signals transmitted with a transmission density of 1 time/ms according to an embodiment of the present invention;

5 is a schematic diagram of an apparatus for improving downlink efficiency of an LTE network provided according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of an electronic device provided according to an embodiment of the present invention.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

FIG. 1 is a flowchart of a method for improving downlink efficiency of an LTE network provided by an embodiment of the present invention. As shown in FIG. 1 , a method for improving downlink efficiency of an LTE network includes: S11 , adjusting the in-service area according to the scene type of the service area The transmission density of cell-specific reference signals in the downlink signal, and the scenario types include high-speed scenarios, medium-low speed scenarios, slow-speed and static scenarios, and mixed scenarios; S12, transmit cell-specific reference signals to each terminal in the service area according to the adjusted transmission density .

Specifically, when the mobile station moves in a certain direction at a constant rate, due to the difference in propagation path, a change in phase and frequency will be caused, and this change is usually called the Doppler effect. The difference between the transmitted and received frequencies caused by the Doppler effect is called the Doppler shift; the faster the mobile station, the greater the Doppler shift. According to the Doppler frequency shift formula, assuming that the LTE signal transmitter operates in the D-band (2.6GHz), the Doppler frequency shift fm generated by the 350Km/h high-speed rail is between -850Hz and +850Hz, and the total change is 1700Hz. In order to ensure that the signal is not distorted, according to the Nyquist sampling theorem, the sampling frequency is at least 2 times greater than the change amount, that is, greater than 3.4KHz, and the positive value is 4KHz, that is, 4 times/ms are required. Communication needs, currently, the transmission density of cell-specific reference signals is uniformly set to 4 times/ms.

For different numbers of antenna ports, the RE location map of CRS transmitted with a transmission density of 4 times/ms is shown in Figure 2. Taking 1 RB as an example, it contains 84 REs in total, and the proportion of CRS in downlink resources can be obtained:

For a single antenna (1 antenna), CRS accounts for 4 REs, and the proportion of CRS is 4/84=4.8%;

For dual antennas (2 antennas), CRS accounts for 8 REs, and the proportion of CRS is 8/84=9.6%;

For four antennas (4 antennas), the CRS occupies 12 REs, and the ratio of the CRS is 12/84=14.4%.

Since the CRS is only equivalent to a pilot signal and is not used to transmit the user's communication data, the larger the proportion of CRS, the lower the proportion of the downlink signal used to transmit the user's communication data, and the lower the downlink efficiency. , under the premise of not affecting the system performance, if the proportion of CRS can be reduced, the precious wireless resources can be utilized to a greater extent, and the downlink efficiency of the LTE network will be higher.

For most cells, the service scenarios are not high-speed scenarios such as high-speed rail. For terminals in low-to-medium-speed scenarios, slow-speed and stationary scenarios, the moving speed of these terminals is much lower than that of high-speed rail. The Pler frequency shift formula, the Doppler frequency shift at low speed is relatively small, and the sampling frequency is relatively small, so the transmission density of CRS does not need to reach 4 times/ms, and it can also ensure that the terminal can receive signals without distortion. For a terminal in any scenario, the CRS transmission density is maintained at 4 times/ms, which will inevitably lead to waste of downlink resources and low downlink efficiency.

In this embodiment, the transmission density of the cell-specific reference signals in the downlink signals in the service area is adjusted according to the scene type of the service area, especially for low-to-medium-speed scenarios, slow-speed and static scenarios, the transmission density of the cell-specific reference signals can be correspondingly reduced , and then transmit the cell-specific reference signal to each terminal in the service area according to the adjusted transmission density, which can reduce the proportion of the CRS in the downlink signal, so as to improve the downlink efficiency of the LTE network.

The method of this embodiment adjusts the transmission density of the cell-specific reference signals in the downlink signals in the service area according to the scene type. For medium-low-speed scenarios, slow-speed and static scenarios, the transmission density can be adjusted to be much lower than the currently specified 4 times/ms , the occupancy of the cell-specific reference signal in the downlink signal can be reduced, so that the downlink signal can use more resources to transmit the user's communication data service, thereby improving the downlink efficiency of the LTE network.

Based on the above embodiment, further, adjusting the transmission density of the cell-specific reference signals in the downlink signals in the service area according to the scene type of the service area includes: obtaining a preset code corresponding to the scene type of the service area; The transmission density is adjusted to the transmission density of the cell-specific reference signals in the downlink signals in the service area.

Wherein, before acquiring the preset code corresponding to the scene type of the service area, the method further includes: encoding each scene type according to preset rules to obtain the preset code corresponding to each scene type; setting a preset code for each preset code emission density.

Specifically, for the LTE communication system, when planning the cell base station, the scene type of each cell can be set according to the characteristics of the cell coverage area, and the scene type can be coded. The scene code is 01, the slow and still scene code is 10, the mixed scene code is 11, and 00, 01, 10, and 11 are used as the preset codes for the corresponding scenes, and an emission density is set for each preset code. For example , on the basis of meeting the terminal requirements in different scenarios, set the emission density to 4 times/ms for 00, set the emission density to 2 times/ms for 01, set the emission density to 1 time/ms for 10, and set the emission density to 11. The density is 4 times/ms; the base station obtains the preset coding of the scene corresponding to the cell, adjusts the transmission density set for the preset coding to the transmission density of the cell-specific reference signal of the cell, and then adjusts the transmission density according to the transmission density set for the preset coding. Terminals within the cell coverage area transmit CRS. For preset coding, it can be stored in PBCH. PBCH has a total of 24 bits, including system bandwidth, PHICH parameter configuration, system frame number and other information. These information have occupied 14 bits, and 2 bits of the remaining 10 bits are used to store preset coding. Reserved bits to store preset codes can minimize changes to the transmission protocol and simplify the design of the terminal.

Based on the above embodiment, further, setting an emission density for each preset code includes: for any preset code, taking the scene type corresponding to the any preset code as the target scene type, and determining the corresponding scene type of the target scene type. The highest moving speed of the terminal in the scene; the target emission density is determined according to the highest moving speed, and the target emission density is set as the emission density set for any one of the preset codes, so as to set an emission density for each preset code.

Among them, the target emission density is determined according to the highest moving speed, including: determining the Doppler frequency shift caused by the highest moving speed; based on the Nyquist sampling theorem, determining the sampling frequency according to the Doppler frequency shift to ensure that the cell-specific reference signal is not distorted ; Determine the target emission density according to the sampling frequency.

Specifically, according to the Doppler frequency shift formula and the LTE signal transmitter operating in the D-band (2.6GHz), for the high-speed scenario, the highest moving speed in the high-speed scenario is the terminal in the high-speed rail, and the Doppler frequency generated by the high-speed rail 350Km/h The shift fm is between -850Hz and +850Hz, and the total change is 1700Hz; in order to ensure that the signal is not distorted, according to the Nyquist sampling theorem, the sampling frequency should be at least twice the change, that is, greater than 3.4KHz. It is 4KHz, that is, 4 times/ms are required. Similarly, for medium and low speed scenarios, the moving speed of the terminal will not exceed 120Km/h, and the maximum Doppler frequency shift will not exceed 500Hz, which can reduce the transmission density of CRS to 2 times/ms; for slow and stationary scenarios, The terminal is basically in a stationary or slow-moving state, which can further reduce the transmission density of CRS to 1 time/ms or even lower; for mixed scenarios, there may be high-speed moving terminals such as high-speed rail, and the transmission density of CRS can be kept at the highest. 4 times/ms.

For medium and low speed scenarios, under different numbers of antenna ports, the RE position map of CRS transmitted with a transmission density of 2 times/ms is shown in Figure 3. Compared with Figure 2, the position RE of some CRS can be converted into user communication Service wireless resources:

For a single antenna (1 antenna), the downlink efficiency can be improved by about 2.5%;

For dual antennas (2 antennas), the downlink efficiency can be improved by about 5%;

For four antennas (4 antennas), the downlink efficiency can be improved by about 7.5%.

Similarly, for medium and low speed scenarios, under different numbers of antenna ports, the RE position map of CRS transmitted at a transmission density of 2 times/ms is shown in Figure 4. Compared with Figure 2, the position REs of some CRSs can be converted into The wireless resources of the user's communication service:

For a single antenna (1 antenna), the downlink efficiency can be improved by about 3.25%;

For dual antennas (2 antennas), the downlink efficiency can be improved by about 7.5%;

For four antennas (4 antennas), the downlink efficiency can be improved by about 10%.

For mixed scenarios, under different numbers of antenna ports, the RE location map of the CRS transmitted at a transmission density of 4 times/ms is the same as the location map corresponding to the high-speed scenario, as shown in Figure 2.

It can be seen from the above data that adjusting the transmission density of the CRS according to the scenario type can effectively improve the downlink efficiency of the LTE network as a whole.

Based on the above embodiment, further, after obtaining the preset code corresponding to the scene type of the service area, the method includes: sending the preset code corresponding to the scene type of the service area to each terminal in the service area, so that each terminal can use the service area according to the service area. The preset code corresponding to the scene type of the area parses the RE map of the downlink signal in the service area.

Specifically, as shown in Figure 2, Figure 3 and Figure 4, the base station transmits data with different CRS transmission densities, and the corresponding RE maps are different. Therefore, the terminal needs to use different RE maps in different types of scenarios. The base station needs to send the preset code corresponding to the scene type to the terminal in the service area, and the terminal selects the format of the corresponding RE map according to the preset code for information processing, so as to realize the accurate decoding of the downlink data. Through this implementation The method provided by the example can not only realize accurate decoding of downlink data by the terminal, but also improve the downlink efficiency of the LTE network.

FIG. 5 is a schematic diagram of an apparatus for improving the downlink efficiency of an LTE network provided by an embodiment of the present invention. As shown in FIG. 5 , an apparatus for improving the downlink efficiency of an LTE network includes: an adjustment module 51 and a transmission module 52, wherein:

The adjustment module 51 is used to adjust the transmission density of the cell-specific reference signals in the downlink signals in the service area according to the scene type of the service area, and the scene types include high-speed scene, medium-low speed scene, slow and static scene and mixed scene; the transmitting module 52, It is used to transmit a cell-specific reference signal to each terminal in the service area according to the adjusted transmission density.

The apparatuses in the embodiments of the present invention can be used to implement the technical solutions of the foregoing method embodiments, and the implementation principles and technical effects thereof are similar, which will not be repeated here.

FIG. 6 is a schematic diagram of an electronic device provided according to an embodiment of the present invention. As shown in FIG. 6, an electronic device includes: at least one processor 61, at least one memory 62, and a data bus 63; wherein: the processor 61 and the memory 62 completes mutual communication through the data bus 63; the memory 62 stores program instructions that can be executed by the processor 61, and the processor 61 invokes the program instructions to execute the methods for improving the downlink efficiency of the LTE network provided by the above method embodiments, such as Including: adjusting the transmission density of cell-specific reference signals in downlink signals in the service area according to the scene type of the service area. Each terminal in the area transmits a cell-specific reference signal.

Embodiments of the present invention provide a non-transitory computer-readable storage medium, where the non-transitory computer-readable storage medium stores a computer program, and the computer program enables the computer to execute the method for improving the downlink efficiency of an LTE network provided by the foregoing method embodiments. The method, for example, includes: adjusting the transmission density of cell-specific reference signals in downlink signals in the service area according to the scene type of the service area, the scene types include high-speed scene, medium-low speed scene, slow and static scene and mixed scene; according to the adjusted transmission The density transmits a cell-specific reference signal to each terminal within the service area.

Those of ordinary skill in the art can understand that all or part of the steps of implementing the above method embodiments can be completed by instructing relevant hardware by a computer program, and the aforementioned computer program can be stored in a computer-readable storage medium, and the computer program executes At the time, the steps including the above method embodiments are performed; and the aforementioned storage medium includes: ROM, RAM, magnetic disk or optical disk and other media that can store program codes.

The device embodiments described above are only illustrative, wherein the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in One place, or it can be distributed over multiple network elements. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution in this embodiment. Those of ordinary skill in the art can understand and implement it without creative effort.

From the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, and certainly can also be implemented by hardware. Based on this understanding, the above-mentioned technical solutions can be embodied in the form of software products in essence or the parts that make contributions to the prior art, and the computer software products can be stored in computer-readable storage media, such as ROM/RAM, magnetic A disc, an optical disc, etc., includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform the methods described in various embodiments or some parts of the embodiments.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still be used for The technical solutions described in the foregoing embodiments are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (9)

1. a method for improving LTE network downlink efficiency, is characterized in that, comprises: Adjust the transmission density of cell-specific reference signals in downlink signals in the service area according to the scene type of the service area, the scene types include high-speed scene, medium-low speed scene, slow and static scene and mixed scene; A cell-specific reference signal is transmitted to each terminal within the service area according to the adjusted transmission density. 2 . The method according to claim 1 , wherein the adjusting the transmission density of cell-specific reference signals in downlink signals in the service area according to the scene type of the service area comprises: 2 . obtaining the preset code corresponding to the scene type of the service area; The transmission density set for the preset coding is adjusted to the transmission density of the cell-specific reference signals in the downlink signals in the service area. 3. The method according to claim 2, wherein before acquiring the preset code corresponding to the scene type of the service area, the method further comprises: Encode each scene type according to a preset rule to obtain a preset code corresponding to each scene type; A transmit density is set for each preset code. 4. The method according to claim 3, wherein the setting an emission density for each preset code comprises: For any preset encoding, use the scene type corresponding to any preset encoding as the target scene type, and determine the highest moving speed of the terminal in the scene corresponding to the target scene type; The target emission density is determined according to the highest moving speed, and the target emission density is used as the emission density set for any one of the preset codes, so that one emission density is set for each preset code. 5. The method according to claim 4, wherein the determining the target emission density according to the highest moving speed comprises: determining the Doppler shift caused by the highest moving speed; Based on the Nyquist sampling theorem, determining a sampling frequency that ensures that the cell-specific reference signal is not distorted according to the Doppler frequency shift; The target emission density is determined based on the sampling frequency. 6. The method according to claim 2, wherein after acquiring the preset code corresponding to the scene type of the service area, the method comprises: Send the preset code corresponding to the scene type of the service area to each terminal in the service area, so that each terminal can parse the downlink signal in the service area according to the preset code corresponding to the scene type of the service area RE map of . 7. A device for improving downlink efficiency of an LTE network, comprising: an adjustment module, configured to adjust the transmission density of the cell-specific reference signals in the downlink signals in the service area according to the scene type of the service area, the scene types include high-speed scene, medium-low speed scene, slow and static scene and mixed scene; and a transmitting module, configured to transmit a cell-specific reference signal to each terminal in the service area according to the adjusted transmission density. 8. An electronic device, characterized in that, comprising: at least one processor, at least one memory, and a data bus; wherein: The processor and the memory communicate with each other through the data bus; the memory stores program instructions executable by the processor, and the processor invokes the program instructions to execute the program as claimed in claim 1 The method of any one of to 6. 9 . A non-transitory computer-readable storage medium, characterized in that, the non-transitory computer-readable storage medium stores a computer program, and the computer program causes the computer to execute any one of claims 1 to 6 . Methods.

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