MIMO system feeding signals at two ends of leaky coaxial cable, and signal intensity equalization method

Abstract

The present application belongs to the technical field of mobile communications, and provides an MIMO system feeding signals at two ends of a leaky coaxial cable, and a signal intensity equalization method. The slotting mode of an outer conductor of a leaky coaxial cable uses a segmented design in the length direction of the leaky coaxial cable, so as to achieve the characteristics of low radiation performance at a signal input end and high radiation performance at a midpoint O of the leaky coaxial cable, thus achieving relatively equalized signal intensity throughout the whole leaky coaxial cable range, increasing the signal-to-noise ratio of a terminal signal coverage area, and improving the quality of leaky feeder communication; in addition, signal controllers and positioning base stations are additionally provided between RRU devices and POIs, and the signal intensity difference between radiation signals of first feed-in end and second feed-in end input signals of the leaky coaxial cable at a mobile terminal is calculated, so as to adjust the intensities of signals fed into a first feed-in end or a second feed-in end, thus controlling the intensities of two paths of signals received by the mobile terminal within a device processing range, ameliorating the unequalization of the signal intensities of the two paths of signals, and improving signal quality.

Description

MIMO system with signals fed into both ends of a leaky cable and signal strength equalization method Technical Field

[0001] The present application relates to the field of mobile communication technology, and in particular to a MIMO system for feeding signals into both ends of a leaky cable and a signal strength equalization method. Background Art

[0002] Traditional MIMO (Multiple Receive, Multiple Transmit) is achieved by adding antennas. In tunnel scenarios, this requires increasing the number of leaky cables deployed. To implement 2×2 MIMO in a subway tunnel, the traditional solution is to deploy two leaky cables. Two channels of RF signals are fed simultaneously from the in-phase ends of the two cables. The receiver receives the RF signals from both channels through the radiation from the two leaky cables, creating a dual-path effect. However, subway tunnels are small, and the number of leaky cables that can be deployed is very limited. To reduce the space occupied by leaky cables in the tunnel and lower deployment costs, research is underway to develop MIMO systems that utilize leaky cables fed from both ends.

[0003] However, the MIMO performance of a leaky cable dual-end feed signal MIMO system is significantly affected by the imbalance of the feed signals at both ends. If the signal strength difference between the two inputs is large, the difference in the strength of the two signals received by the mobile terminal may exceed the processing range of the device, affecting the communication quality. In addition, in narrow and long scenarios such as tunnels, the MIMO channel capacity of the leaky cable is high at the two ends and low in the middle. As the horizontal distance between the leaky cable and the receiving antenna increases, the MIMO channel capacity of the leaky cable gradually decreases. This is because the signal power radiated from the slot at the signal input end of the leaky cable is higher than the signal power radiated from the slot in the middle area. Therefore, the received signal strength near the two ends of the leaky cable is higher than the received signal strength near the middle of the leaky cable. In order to meet the communication conditions in the middle, the signal is generally required to be very strong in a long area between the two starting ends, which actually results in a lot of energy waste.

[0004] Summary of the Invention

[0005] In view of this, the purpose of the present application is to provide a MIMO system with signals fed into both ends of a leaky cable and a signal strength equalization method.

[0006] In the first aspect, an embodiment of the present application provides a MIMO system with unevenly distributed leakage cable feeding signals at both ends, including a first POI, a first signal controller, a first RRU device, a first positioning base station, a second POI, a second signal controller, a second RRU device, a second positioning base station and at least one leakage cable; the first end signal of the leakage cable is connected to the first POI, and the second end signal of the leakage cable is connected to the second POI; the first signal controller signal is connected to the first RRU device, the first positioning base station and the first POI; the second signal controller signal is connected to the second RRU device, the second positioning base station and the second POI; the PCI of the first RRU device and the second RRU device are set to the same; the radiation performance of the two ends of the leakage cable is weaker than that at the midpoint of the leakage cable, but the transmission performance of the two ends of the leakage cable is stronger than that at the midpoint of the leakage cable; the first signal controller or the second signal controller is used to obtain the location information of the mobile terminal from the positioning base station connected to its signal, and calculate according to the location information The length of the mobile terminal from the first feeding end or the second feeding end of the target leaky cable along the extension direction of the target leaky cable, wherein the target leaky cable belongs to the at least one leaky cable; obtaining radiation performance information of the target leaky cable length interval, wherein the radiation performance information includes the number of segments and the length of each segment, the loss constant per hundred meters, and the coupling loss, and calculating the signal strength difference of the radiation signal of the first feeding end and the second feeding end input signal of the target leaky cable at the mobile terminal based on the length of the mobile terminal from the first feeding end or the second feeding end of the target leaky cable along the extension direction of the target leaky cable and the radiation performance information; the first signal controller is used to adjust the signal strength fed into the first feeding end of the at least one leaky cable in response to the signal strength difference being greater than a preset difference threshold, and / or the second signal controller is used to adjust the signal strength fed into the second feeding end of the at least one leaky cable in response to the signal strength difference being greater than the preset difference threshold, so that the signal strength difference is less than the preset difference threshold.

[0007] In some embodiments, the leaky cable is divided into at least two sections from the signal feeding end to the midpoint of the leaky cable, the arrangement of the slot group in the same section of the leaky cable is the same, and the slots in the slot group in the same section of the leaky cable are arranged sequentially along the same radial area position in the length direction of the leaky cable, and the loss constant per 100 meters of different sections of the leaky cable from the signal feeding end to the midpoint of the leaky cable gradually increases, and the coupling loss gradually decreases.

[0008] In some embodiments, the number of the leaky cables is no less than two, and the radiation polarization directions of all slot groups of the same leaky cable are the same; the polarization directions of all leaky cables are the same, and the number and length of segments of all leaky cables are consistent.

[0009] In some embodiments, the number of the leaky cables is no less than two, the radiation polarization directions of all slot groups of the same leaky cable are the same, the radiation polarization directions of adjacent leaky cables are different, and the number and length of segments of all leaky cables are the same.

[0010] In some embodiments, the first signal controller and the second signal controller both include a signal strength adjustment module, and the signal strength adjustment module includes a control circuit, an attenuator, and an amplifier. The control circuit signal is connected to the attenuator or the amplifier, and the attenuator and the amplifier are connected in series.

[0011] In some embodiments, the signal strength adjustment module further includes a switching circuit and a gating switch, wherein the gating switch is connected in parallel at both ends of the attenuator or amplifier, and the switching circuit signal is connected to the gating switch and can control the conduction and disconnection of the gating switch.

[0012] In the second aspect, an embodiment of the present application provides a signal strength equalization method for a MIMO system with unevenly distributed feed signals at both ends of a leaky cable, comprising the following steps: setting the PCI of the RRU devices at both ends of the leaky cable to be the same; obtaining the location information of the mobile terminal, and calculating the length of the mobile terminal from the first feeding end or the second feeding end of the leaky cable along the extension direction of the leaky cable based on the location information; obtaining the radiation performance information of the length interval of the leaky cable, the radiation performance information including the number of segments and the length of each segment, the loss constant per hundred meters and the coupling loss, and calculating the signal strength difference of the radiation signal of the input signal from the first feeding end and the second feeding end of the leaky cable at the mobile terminal based on the length of the mobile terminal from the first feeding end or the second feeding end of the leaky cable along the extension direction of the leaky cable and the radiation performance information; and adjusting the signal strength of the signal fed into the first feeding end or the second feeding end based on the signal strength difference being greater than a preset difference threshold, so that the signal strength difference of the radiation signal of the input signal from the first feeding end and the second feeding end of the leaky cable received by the mobile terminal is less than the preset difference threshold.

[0013] In some embodiments, calculating the signal strength difference includes the steps of: calculating a first transmission loss of a signal fed from a first feeding end to the mobile terminal based on a length of the mobile terminal from a first feeding end of the leaky cable along an extension direction of the leaky cable, a length of each segment between the mobile terminal and the first feeding end, and a loss constant per 100 meters of each segment; calculating a second transmission loss of a signal fed from a second feeding end to the mobile terminal based on a length of the mobile terminal from a second feeding end of the leaky cable along an extension direction of the leaky cable, a length of each segment between the mobile terminal and the second feeding end, and a loss constant per 100 meters of each segment; and taking the absolute value of the difference between the first transmission loss and the second transmission loss as the signal strength difference.

[0014] In some embodiments, the step of adjusting the signal strength fed into the first feeding end or the second feeding end includes: attenuating the strength of the feeding signal at the end that is closer to the mobile terminal along the length direction of the leaky cable, or amplifying the strength of the feeding signal at the end that is farther from the mobile terminal along the length direction of the leaky cable.

[0015] In some embodiments, the preset difference threshold does not exceed 20 dB.

[0016] The beneficial effects that this application can achieve.

[0017] The present application provides a MIMO system for feeding signals at both ends of a leaky cable and a signal strength balancing method, in which the slotting mode of the outer conductor of the leaky cable is designed in sections along the length direction of the leaky cable, and the loss constant per 100 meters of the leaky cable in different sections from the signal feeding end to the midpoint of the leaky cable gradually increases, and the coupling loss gradually decreases, so as to obtain the characteristics of weak radiation performance at the signal input end but good transmission performance, weak transmission performance at the midpoint O of the leaky cable but strong radiation performance, and appropriately reduce the radiation performance and enhance the transmission performance while ensuring that the first feeding end A and the second feeding end B of the signal input end of the leaky cable meet the communication requirements, appropriately weaken the transmission performance and improve the radiation performance at the midpoint O of the leaky cable, so that the signal strength of the entire leaky cable section is more balanced, the signal-to-noise ratio of the terminal signal coverage area is improved, and the leakage communication quality is improved, and a signal controller and a positioning base station are added between the RRU device and the POI, and the positioning base station is used to obtain the mobile terminal The device uses the position information of the terminal to calculate the length of the mobile terminal from the first feeding end or the second feeding end of the leaky cable along the extension direction of the leaky cable by using the signal controller, and calculates the signal strength difference of the radiation signal of the input signal from the first feeding end and the second feeding end of the leaky cable at the mobile terminal according to the length of the mobile terminal from the first feeding end or the second feeding end of the leaky cable along the extension direction of the leaky cable and the radiation performance information of the leaky cable, compares the signal strength difference with a preset difference threshold, and when the signal strength difference is greater than the preset difference threshold, adjusts the signal strength fed into the first feeding end or the second feeding end, so that the signal strength difference of the radiation signal of the input signal from the first feeding end and the second feeding end of the leaky cable received by the mobile terminal is less than the preset difference threshold, thereby controlling the strength of the two signals received by the mobile terminal within the processing range of the device, improving the imbalance of the signal strength of the two signals, and improving the signal quality.

[0018] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0020] FIG1 shows a 2×2 MIMO system of the present invention in which signals are fed into leaky cables at both ends in a non-uniform distribution;

[0021] FIG2 is a flow chart showing a method for equalizing signal strength of a MIMO system with non-uniformly distributed leaky cable feed signals at both ends of the present application;

[0022] FIG3 shows a schematic diagram of the principle of a signal strength adjustment module in the present application;

[0023] FIG4 shows a schematic diagram of a specific implementation of a signal strength adjustment module using multiple attenuators and operational amplifiers connected in series in the present application;

[0024] FIG5 shows a 4×4 MIMO system in which a non-uniformly distributed leaky cable with the same polarization is fed into both ends of the cable;

[0025] FIG6 shows an 8×8 MIMO system in which the same polarization is used in a non-uniformly distributed leaky cable feeding signal at both ends of the present application;

[0026] FIG7 shows a 4×4 MIMO system in which adjacent leaky cables of the present application use different polarizations and feed signals at both ends of the leaky cables in a non-uniform distribution;

[0027] FIG8 shows an 8×8 MIMO system of the present application in which adjacent leaky cables use non-uniformly distributed feed signals at both ends of the leaky cables with different polarizations;

[0028] FIG9 shows a schematic diagram showing the principle of a signal strength equalization device for a MIMO system with non-uniformly distributed leaky cable feed signals according to the present invention.

[0029] Wherein: 1-leakage cable, 2-mobile terminal, 3-first POI, 4-first signal controller, 5-first RRU device, 6-second POI, 7-second signal controller, 8-second RRU device, 9-first positioning base station, 10-second positioning base station, A-first feeding end, B-second feeding end, L-leakage cable length, O-leakage cable midpoint, y-length from mobile terminal to first feeding end along the leakage cable axis, Ly-length from mobile terminal to second feeding end along the leakage cable axis, I1-first segment, I2-second segment, I3-third segment, 11-signal Strength adjustment module, 12-control circuit, 13-storage module, 14-attenuator, 15-amplifier, 16-switching circuit, 17-select switch, 18-first operational amplifier, 19-second operational amplifier, 20-third operational amplifier, 21-first fixed attenuator, 22-second fixed attenuator, 23-first adjustable attenuator, 24-second adjustable attenuator, 25-first leaky cable, 26-second leaky cable, 27-third leaky cable, 28-fourth leaky cable, 29-signal strength equalization device, 31-position calculation module, 32-signal strength difference calculation module. DETAILED DESCRIPTION

[0030] The term "comprising" in the specification, claims, and drawings of this application is synonymous with "including," "containing," or "characterized by," and is inclusive or open-ended and does not exclude additional unrecited elements or method steps. "Comprising" is a technical term used in claim language to mean that the recited elements are present, but other elements may be added and still form a structure or method within the scope of the claim.

[0031] It should be noted that similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description and are not to be understood as indicating or implying relative importance. The term "about" in this application is meant to include slight variations (up to + / - 10%) from the stated value.

[0032] In this application, it has been found that the MIMO performance of the leaky cable double-end feeding signal MIMO system is greatly affected by the imbalance of the feed signals at both ends. If the difference in the signal strength of the two inputs is large, the difference in the strength of the two signals received by the mobile terminal may exceed the processing range of the device, affecting the communication quality. In addition, in narrow and long scenarios such as tunnels, the capacity of the leaky cable MIMO channel is high at both ends and low in the middle, and as the horizontal distance between the leaky cable and the receiving antenna increases, the capacity of the leaky cable MIMO channel gradually decreases. This is because at the signal input ends of the leaky cable at both ends, the signal power radiated by the slot at this position is higher than the signal power radiated by the slot in the middle area. Therefore, the received signal strength near the two ends of the leaky cable is higher than the received signal strength near the middle position of the leaky cable. In order to meet the communication conditions in the middle position, the signal is generally required to be very strong in a long area between the two starting ends, which actually results in a lot of energy waste.

[0033] In order to control the imbalance of the feed signal at both ends of the leaky cable, control the strength difference of the feed signal, and balance the signal strength difference along the leaky cable to avoid waste of field strength, the present application provides a signal strength equalization method for a MIMO system with unevenly distributed feed signals at both ends of the leaky cable, comprising the following steps: setting the PCI (physical cell identifier) ​​of the RRU (radio frequency remote unit) devices at both ends of the leaky cable to be the same; obtaining the location information of the mobile terminal, and calculating the distance of the mobile terminal from the first feed end or the second feed end of the leaky cable along the extension direction of the leaky cable based on the location information; obtaining radiation performance information of the length interval of the leaky cable, and The radiation performance information includes the number of segments and the length of each segment, the loss constant per hundred meters and the coupling loss. Based on the length of the mobile terminal from the first feeding end or the second feeding end of the leaky cable along the extension direction of the leaky cable and the radiation performance information, the signal strength difference of the radiation signal of the input signal from the first feeding end and the second feeding end of the leaky cable at the mobile terminal is calculated; based on the signal strength difference being greater than a preset difference threshold, the signal strength fed into the first feeding end or the second feeding end is adjusted so that the signal strength difference of the radiation signal of the input signal from the first feeding end and the second feeding end of the leaky cable received by the mobile terminal is less than the preset difference threshold.

[0034] In some embodiments, the leaky cable is divided into at least two sections from the signal feeding end to the midpoint of the leaky cable, the arrangement of the slot group in the same section of the leaky cable is the same, and the slots in the slot group in the same section of the leaky cable are arranged sequentially along the same radial area position in the length direction of the leaky cable, and the radiation performance of different sections of the leaky cable from the signal feeding end to the midpoint of the leaky cable gradually increases, and the transmission performance gradually decreases.

[0035] In some embodiments, the number of the leaky cables is not less than two, the number and length of segments of all the leaky cables are the same, and the radiation polarization directions of all slot groups of the same leaky cable are the same; the polarization directions of all the leaky cables are the same or the radiation polarization directions of adjacent leaky cables are different.

[0036] The signal strength equalization method, device, equipment, medium and MIMO system in the present application are designed to have a slotted pattern on the outer conductor of the leaky cable in sections along the length of the leaky cable to obtain the characteristics of weak radiation performance at the signal input end and strong radiation performance at the midpoint O of the leaky cable, so that the signal strength of the entire leaky cable interval is relatively balanced, the signal-to-noise ratio of the terminal signal coverage area is improved, and the quality of leakage communication is improved. A signal controller and a positioning base station are added between the RRU device and the POI, and the signal strength difference of the radiation signal of the input signal at the first feeding end and the second feeding end of the leaky cable is calculated at the mobile terminal, and the signal strength fed into the first feeding end or the second feeding end is adjusted, so that the strength of the two signals received by the mobile terminal is controlled within the processing range of the device, the imbalance of the signal strength of the two signals is improved, and the signal quality is improved.

[0037] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0038] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0039] Example 1

[0040] Traditional MIMO (Multiple Receive, Multiple Transmit) is achieved by adding antennas. In tunnel scenarios, this requires increasing the number of leaky cables deployed. To implement 2×2 MIMO in a subway tunnel, the traditional solution is to deploy two leaky cables. Two channels of RF signals are fed simultaneously from the in-phase ends of the two cables. The receiver receives the RF signals from both channels through the radiation from the two leaky cables, creating a dual-path effect. However, subway tunnels are small, and the number of leaky cables that can be deployed is very limited. To reduce the space occupied by leaky cables in the tunnel and lower deployment costs, research is underway to develop MIMO systems that utilize leaky cables fed from both ends.

[0041] However, the MIMO performance of a leaky cable dual-end feed signal MIMO system is significantly affected by the imbalance of the feed signals at both ends. If the signal strength difference between the two inputs is large, the difference in the strength of the two signals received by the mobile terminal may exceed the processing range of the device, affecting the communication quality. In addition, in narrow and long scenarios such as tunnels, the MIMO channel capacity of the leaky cable is high at the two ends and low in the middle. As the horizontal distance between the leaky cable and the receiving antenna increases, the MIMO channel capacity of the leaky cable gradually decreases. This is because the signal power radiated from the slot at the signal input end of the leaky cable is higher than the signal power radiated from the slot in the middle area. Therefore, the received signal strength near the two ends of the leaky cable is higher than the received signal strength near the middle of the leaky cable. In order to meet the communication conditions in the middle, the signal is generally required to be very strong in a long area between the two starting ends, which actually results in a lot of energy waste.

[0042] In order to control the imbalance of the feed signals at both ends of the leaky cable, control the strength difference of the feed signals, and balance the signal strength difference along the leaky cable to avoid waste of field strength, the present application provides a MIMO system and control method for unevenly distributing the feed signals at both ends of the leaky cable.

[0043] Subway tunnels and high-speed rail tunnels are covered by narrow and long lines. In order to minimize the impact of excessive handovers on user perception, cell merging technology is generally used to merge multiple RRUs (remote radio units) into the same cell. As shown in Figure 1, the first RRU device 5 and the second RRU device 8 are set as super cells (Supper Cell), that is, they have the same PCI (Physical Cell Identifier). A super cell is a logical cell configured with two or more RRU devices or sectors, which have the same Cell ID and perform unified resource scheduling. In high-speed mobile scenarios such as subway coverage, high-speed rail coverage, and route coverage, super cells are used to reduce the number of cells and increase the scope of a single cell, thereby reducing handovers and ensuring communication reliability.

[0044] In the present application, the RRU (remote radio unit) device includes at least one operator's RRU, such as China Telecom 2G / 3G / 4G RRU, China Unicom 2G / 3G / 4G RRU, China Mobile 2G / 3G / 4G RRU, China Telecom Unicom 5G RRU, and China Mobile 5G RRU. POI (POINT OF INTERFACE), that is, a multi-system access platform, is used for multi-band and multi-signal combining to achieve compatible coverage of multi-network signals, mainly to achieve multi-system and multi-band signal transceiver, combining and splitting cable transmission. Positioning base stations, such as the first positioning base station 9 (or the second positioning base station 10), can provide location information of mobile terminals, such as the location information of mobile phone users, and obtain the location information (geographic coordinates, or geodetic coordinates) of user terminals through the operator's radio communication network (such as GSM network, CDMA network) or external positioning methods (such as GPS).

[0045] As shown in Figure 1, a schematic diagram of the structure of a MIMO system with unevenly distributed signal feeds at both ends of a leaky cable includes a first RRU device 5, a first signal controller 4, a first point of interest (POI) 3, a first positioning base station 9, a leaky cable 1, a second RRU device 8, a second signal controller 7, a second point of interest (POI) 6, and a second positioning base station 10. The first signal controller 4 connects the first RRU device 5, the first positioning base station 9, and the first POI 3. The second signal controller 7 connects the second RRU device 8, the second positioning base station 10, and the second POI 6. The first POI 3 connects the first feed-in terminal A of the leaky cable 1, and the second POI 6 connects the second feed-in terminal B of the leaky cable 1. The first signal controller 4 or the second signal controller 7 is used to obtain the location information of the mobile terminal from the positioning base station connected to its signal, and calculate the length of the mobile terminal from the first feeding end or the second feeding end of the target leaky cable along the extension direction of the leaky cable based on the location information, and the target leaky cable belongs to the at least one leaky cable; obtain the radiation performance information of the target leaky cable length interval, the radiation performance information includes the number of segments and the length of each segment, the loss constant per hundred meters and the coupling loss, and calculate the signal strength difference of the radiation signal of the input signal of the first feeding end and the second feeding end of the target leaky cable at the mobile terminal based on the length of the mobile terminal from the first feeding end or the second feeding end of the target leaky cable along the extension direction of the target leaky cable and the radiation performance information.

[0046] Furthermore, the first signal controller 4 is used to adjust the signal strength fed into the first feeding end of the at least one leaky cable in response to the signal strength difference being greater than a preset difference threshold, and / or the second signal controller 7 is used to adjust the signal strength fed into the second feeding end of the at least one leaky cable in response to the signal strength difference being greater than a preset difference threshold, so that the signal strength difference is less than the preset difference threshold.

[0047] In addition, as shown in FIG1 , when there is only one leaky cable 1, this leaky cable 1 is the target leaky cable; when there are multiple leaky cables 1, any one of the multiple leaky cables 1 can be designated as the target leaky cable. The first signal controller 4 or the second signal controller 7 can obtain a corresponding signal strength difference based on the target leaky cable, and in response to the signal strength difference being greater than a preset difference threshold, the first signal controller 4 and / or the second signal controller 7 performs corresponding processing on the signals fed into all the leaky cables.

[0048] The length L of the leaky cable, for example, in a subway tunnel scenario, is usually 400-600 meters. The slots on the leaky cable 1 are non-uniformly distributed. Specifically, the leaky cable 1 is segmented along its length, and slot groups with different radiation performance are set on different segments to form a leaky cable 1. The slots in the leaky cable section between the first feeding end A and the midpoint O of the leaky cable and the second feeding end B and the midpoint O of the leaky cable are set to be non-uniform, and the slots in the leaky cable section between the first feeding end A and the midpoint O of the leaky cable and the second feeding end B and the midpoint O of the leaky cable are set to be symmetrical about the midpoint O of the leaky cable. Specifically, the leaky cable 1 is divided into at least two sections from the first feeding end A to the midpoint O of the leaky cable, and the slot groups in one section of the leaky cable are set the same, and the slots in the slot groups in each section are arranged sequentially along the same radial area position in the length direction of the leaky cable. The loss constant per 100 meters of each section of the leaky cable between the first feed-in terminal A and the midpoint O of the leaky cable gradually increases, causing the transmission performance of each section of the leaky cable between the first feed-in terminal A and the midpoint O of the leaky cable to gradually weaken; the coupling loss of each section of the leaky cable between the first feed-in terminal A and the midpoint O of the leaky cable gradually decreases, causing the radiation performance of each section of the leaky cable between the first feed-in terminal A and the midpoint O of the leaky cable to gradually enhance. While ensuring that the first feed-in terminal A and the second feed-in terminal B of the leaky cable signal input terminal meet the communication requirements, the radiation performance is appropriately reduced and the transmission performance is improved. The transmission performance is appropriately reduced at the midpoint O of the leaky cable, and the radiation performance is improved. A certain amount of radiation performance is sacrificed at the front end of the communication link to ensure a small transmission loss, and an appropriate amount of transmission loss is sacrificed at the end section to increase the radiation performance, thereby improving the signal-to-noise ratio of the end signal coverage area and enhancing the quality of leaky communication.

[0049] In order to balance the signal strength differences along the leaky cable and avoid waste of field strength, in this application, the slotting method of the outer conductor of the leaky cable is designed in sections along the length direction of the leaky cable to obtain the characteristics of weak radiation performance at the signal input end and strong radiation performance at the midpoint O of the leaky cable. The leaky cable from the first feeding end A and the second feeding end B of the signal input end of the leaky cable to the midpoint O of the leaky cable is provided with a group of slots with corresponding radiation performance on the outer conductor of each leaky cable segment length area according to the characteristics of enhanced radiation performance and weakened transmission performance of each section of the leaky cable. The corresponding loss constant per 100 meters of each section of the leaky cable from the first feeding end A and the second feeding end B of the signal input end of the leaky cable to the midpoint O of the leaky cable gradually increases, and the coupling loss of each section of the leaky cable gradually decreases.

[0050] In this embodiment, all slot groups in the same leaky cable have the same main polarization mode when they exist alone, for example, vertical polarization, horizontal polarization, +45° polarization, or -45° polarization. The shape of the slots is set according to the requirements of the polarization direction, such as figure-eight slots, cross-slot slots, and straight vertical slots.

[0051] The parameters that affect the radiation performance of the slot are mainly the pitch, slot length, slot width, and slot inclination. The leaky cable from the first feed-in terminal A and the second feed-in terminal B at the signal input end of the leaky cable to the midpoint O of the leaky cable is divided into at least two sections, namely the first section I1, the second section I2, ..., the Nth section I N , where N is an integer ≥ 2.

[0052] ① When other parameters are the same, the large-pitch slot group generally has poor radiation performance and good transmission performance, while the small-pitch slot group generally has good radiation performance and poor attenuation performance. N The parameters of the slot groups in their respective segments are consistent, the first segment I1, the second segment I2, ..., the Nth segment I N The pitch of the slot group between each section of the slot group gradually decreases, and other parameters are consistent.

[0053] ② When other parameters are the same, the relatively short slot group generally has poor radiation performance and good transmission performance, while the relatively long slot group generally has good radiation performance and poor attenuation performance. N The parameters of the slot groups in their respective segments are consistent, the first segment I1, the second segment I2, ..., the Nth segment I N The slot length of the slot group between each section gradually increases, and other parameters are consistent.

[0054] ③ When other parameters are the same, the relatively narrow slot group generally has poor radiation performance and good transmission performance, while the relatively wide slot group generally has good radiation performance and poor attenuation performance. N The parameters of the slot groups in their respective segments are consistent, the first segment I1, the second segment I2, ..., the Nth segment I N The slot width of the slot group between each section gradually increases, and other parameters are consistent.

[0055] ④ If other parameters are the same, you can also adjust the angle between the slot length and the cable axis, that is, the slot inclination to control (except for the U-shaped slot). A smaller inclination generally has poorer radiation performance and better transmission performance, while a larger inclination generally has better radiation performance and poorer attenuation performance. The first section I1, the second section I2, ..., the Nth section I NThe slot groups have consistent parameters within their respective segments. The first segment I1, the second segment I2, ……, the Nth segment I N The slot opening inclination angles of the slot groups between the segments of the slot group gradually increase, and other parameters are consistent.

[0056] In the segmented design of the radiation performance of a non-uniformly distributed leaky cable, by setting at least one parameter such as pitch, slot length, slot width, and slot opening inclination angle, the radiation performance of each segment of the leaky cable from the signal input end (the first feeding end A and the second feeding end B) of the leaky cable to the midpoint O of the leaky cable can be enhanced, and the transmission performance can be weakened. The slotting method of the above-mentioned leaky cable is designed in segments along the length direction of the leaky cable to obtain the characteristics of weak radiation performance but good transmission performance at the signal input end (the first feeding end A and the second feeding end B), and strong radiation performance but poor transmission performance at the midpoint O of the leaky cable, which can improve the performance at the communication end (the midpoint O of the leaky cable), extend the farthest coverage distance of the signal at the midpoint O of the leaky cable or increase the signal-to-noise ratio at the midpoint O of the leaky cable, and ensure the communication quality at the midpoint O of the leaky cable.

[0057] The MIMO performance of a leaky cable dual-end fed signal MIMO system is greatly affected by the imbalance of the signals fed at both ends. If the signal intensities input at both ends differ greatly, the difference in the signal intensities of the two signals received by the mobile terminal may exceed the processing range of the device, affecting the communication quality. As shown in Figure 1, y represents the length of the mobile terminal along the leaky cable axis from the first feeding end, and L - y represents the length of the mobile terminal along the leaky cable axis from the second feeding end. When L - y < y, that is, L - 2y < 0, that is, the mobile terminal 2 is close to the second feeding end B and far from the first feeding end A. Due to the different positions of the mobile terminal 2 in the leaky cable length interval, there is a difference in the signal intensities of the two signals fed from the first feeding end A and the second feeding end B received by the mobile terminal 2. However, the signal intensities of the two signals received by the mobile terminal 2 should be controlled within the processing range of the device. For example, the maximum difference in the real-time signal intensities of the two signals is 8 dB. If L - y < y, that is, L - 2y < 0, and the mobile terminal 2 is close to the second feeding end B, in order to balance the difference in the signal intensities of the radiation signals of the two signal feeding ends input to the mobile terminal 2, the signal intensity can be amplified before feeding the signal into the first feeding end A, or the signal intensity can be attenuated before feeding the signal into the second feeding end B. If L - y > y, that is, L - 2y > 0, and the mobile terminal 2 is close to the first feeding end A, in order to balance the difference in the signal intensities of the radiation signals of the two signal feeding ends input to the mobile terminal 2, the signal intensity can be attenuated before feeding the signal into the first feeding end A, or the signal intensity can be amplified before feeding the signal into the second feeding end B.

[0058] This embodiment provides a signal strength equalization method for a MIMO system with unevenly distributed feed signals at both ends of a leaky cable. As shown in FIG2 , in this application, at least two RRU devices must be configured as the same cell, and the PCI (physical cell identifier) ​​of the RRU devices (remote radio units) at both ends of the leaky cable must be set to the same. The method includes the following steps:

[0059] S01: Acquire location information of a mobile terminal, and calculate, based on the location information of the mobile terminal, a distance between the mobile terminal and a first feeding end of the leaky cable along an extending direction of the leaky cable or a distance between the mobile terminal and a second feeding end of the leaky cable along an extending direction of the leaky cable;

[0060] S02: Obtain radiation performance information of the length interval of the leaky cable, the radiation performance information including the number of segments and the length of each segment, the loss constant per 100 meters, and the coupling loss; and calculate the signal strength difference of the radiation signal of the input signals of the two signal feeding ends (the first feeding end and the second feeding end) at the mobile terminal based on the distance between the mobile terminal and the first feeding end or the second feeding end of the leaky cable along the extension direction of the leaky cable and the radiation performance information;

[0061] S03: Determine whether the signal strength difference is greater than a preset difference threshold. If so, proceed to step S04. If the signal strength difference is less than or equal to the preset difference threshold, terminate the step and signal strength equalization is not required. The signal strength difference received by the mobile terminal is within the acceptable range for signal processing by the mobile terminal and does not affect signal reception.

[0062] S04: Adjust the signal strength fed into the first feed end or the second feed end according to the signal strength difference, so that the difference between the first signal strength value of the radiation signal of the first feed end input signal and the second signal strength value of the radiation signal of the second feed end input signal received by the mobile terminal is less than a preset difference threshold; the step ends.

[0063] In step S01, the first signal controller 4 and the second signal controller 7 can both calculate the distance between the mobile terminal and the first feeding end and the second feeding end of the leaky cable along the direction in which the leaky cable extends. The first signal controller 4 is connected to the first positioning base station 9, obtains the location information of the mobile terminal 2 from the first positioning base station 9, and calculates the length y between the mobile terminal 2 and the first feeding end A of the leaky cable along the direction in which the leaky cable extends based on the location information of the first feeding end A; based on the length y between the mobile terminal 2 and the first feeding end A of the leaky cable along the direction in which the leaky cable extends and the length L of the leaky cable, the length Ly between the mobile terminal 2 and the second feeding end B of the leaky cable along the direction in which the leaky cable extends is calculated. Similarly, the second signal controller 7 is connected to the second positioning base station 10, obtains the location information of the mobile terminal 2 from the second positioning base station 10, and calculates the length Ly of the mobile terminal 2 from the second feeding end B of the leaky cable along the extension direction of the leaky cable according to the location information of the second feeding end B; according to the length Ly of the mobile terminal 2 from the second feeding end B of the leaky cable along the extension direction of the leaky cable and the length L of the leaky cable, calculates the length L-(Ly)=y of the mobile terminal 2 from the first feeding end A of the leaky cable along the extension direction of the leaky cable.

[0064] In step S02, calculating the signal strength difference includes the steps of: calculating a first transmission loss of a signal fed from the first feeding end to the mobile terminal according to the length of the mobile terminal from the first feeding end of the leaky cable along the extension direction of the leaky cable, the length of each segment between the mobile terminal and the first feeding end, and the loss constant per 100 meters of each segment; calculating a second transmission loss of a signal fed from the second feeding end to the mobile terminal according to the length of the mobile terminal from the second feeding end of the leaky cable along the extension direction of the leaky cable, the length of each segment between the mobile terminal and the second feeding end, and the loss constant per 100 meters of each segment; and taking the absolute value of the difference between the first transmission loss and the second transmission loss as the signal strength difference.

[0065] In step S02, as shown in FIG1 , for example, in one embodiment, the length of the leaky cable is L=500 m, and the leaky cable from the first feeding terminal A and the second feeding terminal B of the leaky cable signal input end to the midpoint O of the leaky cable is divided into three sections, namely the first section I1, the second section I2, and the third section I3.

[0066] The length L1 of the first section I1 is 150m, the loss constant per 100m is α1, which is 7.3dB / 100m, and the coupling loss is L C1 It is 73dB.

[0067] The length L2 of the second segment I2 is 70m, the loss constant per 100m is α2 is 9.2dB / 100m, and the coupling loss is L C2 It is 69dB.

[0068] The length L3 of the third segment I3 is 30m, the loss constant per 100m is α3, which is 19.8dB / 100m, and the coupling loss is L C3 is 60dB.

[0069] First, based on the distance between the mobile terminal and the first or second feed-in end of the leaky cable along the extension direction of the leaky cable, the segment of the leaky cable to which the mobile terminal belongs is obtained, and based on the segment of the leaky cable to which the mobile terminal belongs, the coupling loss of the signal received by the mobile terminal is determined. When the distance between the mobile terminal and the first feed-in end along the axis of the leaky cable is 150≤y≤220m, that is, the mobile terminal 2 is located in the second segment I2 of the leaky cable, then the coupling loss of the signal received by the mobile terminal 2 is L C2 .

[0070] According to the distance between the mobile terminal and the first feeding end of the leaky cable along the extension direction of the leaky cable, the length of each segment between the mobile terminal and the first feeding end, and the loss constant per 100 meters of each segment, the first transmission loss of the signal fed from the first feeding end to the mobile terminal is calculated as [α1L1+α2(y-L1)+L C2 ].

[0071] The signal strength SI1 of the signal fed from the first feeding end A of the leaky cable received by the mobile terminal 2 is SI KA -[α1L1+α2(y-L1)+L C2 ], where SI KA is the signal strength input from the first feeding terminal A.

[0072] According to the distance between the mobile terminal and the second feeding end of the leaky cable along the extension direction of the leaky cable, the length of each segment between the mobile terminal and the second feeding end, and the loss constant per 100 meters of each segment, the second transmission loss of the signal fed from the second feeding end to the mobile terminal is calculated as [α1L1+α2L2+2α3L3+α2(L2+L1-y)+L C2 ].

[0073] The signal strength SI2 of the signal fed from the second feeding end B of the leaky cable received by the mobile terminal 2 is SI KB -[α1L1+α2L2+2α3L3+α2(L2+L1-y)+L C2 ], where SI KB is the signal strength inputted by the second feeding terminal B.

[0074] Then the signal strength difference SI of the radiation signals of the two signal feed end input signals received by the mobile terminal 2 is M =SI1-SI2=(SI KA -SI KB )+[2α3L3+2α2(L2+L1-y)].

[0075] Among them (SI KA -SI KB ) is the signal strength difference of the feed signals at both ends of the leaky cable, and [2α3L3+2α2(L2+L1-y)] is the signal strength difference of the received signal caused by the distance difference between the mobile terminal 2 and the first feed terminal A and the second feed terminal B. In general, (SI KA -SI KB )=0, then the absolute value of the difference between the first transmission loss and the second transmission loss |2α3L3+2α2(L2+L1-y)| is used as the signal strength difference.

[0076] In step S03, the preset difference threshold is a maximum of 20dB. For example, in some embodiments, it can be 20dB, 19dB, 18dB, 17dB, 16dB, 15dB, 14dB, 13dB, 12dB, 11dB, 10dB, 9dB, 8dB, 7.5dB, 7dB, 6.5dB, 6dB, 5.5dB, 5dB, 4.5dB, 4dB, 3.5dB, 3dB, and the like.

[0077] In step S04, the step of adjusting the signal strength fed into the first feeding end or the second feeding end includes: attenuating the strength of the feeding signal at the end that is closer to the mobile terminal along the length direction of the leaky cable, or amplifying the strength of the feeding signal at the end that is farther from the mobile terminal along the length direction of the leaky cable.

[0078] In step S04, in order to balance the signal strength difference of the radiation signals of the input signals of the two signal feeding ends received by the mobile terminal 2, the signal strength can be attenuated before the signal is fed into the first feeding end A [2α3L3+2α2(L2+L1-y)], or the signal strength can be amplified before the signal is fed into the second feeding end B [2α3L3+2α2(L2+L1-y)], or the signal strength can be attenuated before the signal is fed into the first feeding end A and the signal strength can be amplified before the signal is fed into the second feeding end B, and the sum of the multiples of the signal strength attenuation and the signal strength amplification is [2α3L3+2α2(L2+L1-y)].

[0079] In the present application, the first signal controller 4 (or the second signal controller 7) includes a signal strength adjustment module 11, which is used to adjust the signal strength fed into the first feed-in terminal or the second feed-in terminal according to the signal strength difference being greater than a preset difference threshold. As shown in Figure 3, the signal strength adjustment module 11 includes a control circuit 12, a storage module 13, an attenuator 14, and an amplifier 15. The control circuit 12 is connected to the attenuator 14 or the amplifier 15, and the attenuator 14 and the amplifier 15 are connected in series. The control circuit 12 is provided with a storage module 13, and the storage module 13 is provided with setting parameters related to the attenuator 14 or the amplifier 15 related to the calculated signal strength difference of the radiation signal of the input signal of the first feed-in terminal and the second feed-in terminal of the leaky cable at the mobile terminal. The attenuator 14 can be a fixed attenuator or an adjustable attenuator, or a mixed setting of a fixed attenuator and an adjustable attenuator. The amplifier 15 can also be an amplifier with a fixed amplification factor or a digitally controlled amplifier with an adjustable amplification factor, or a combination of an amplifier with a fixed amplification factor and an adjustable digitally controlled amplifier.

[0080] For example, in some embodiments, as shown in FIG4 , the signal strength adjustment module 11 includes a control circuit 12, a storage module 13, a switching circuit 16, a gating switch 17, a first operational amplifier 18, a second operational amplifier 19, a third operational amplifier 20, a first fixed attenuator 21, a second fixed attenuator 22, a first adjustable attenuator 23, and a second adjustable attenuator 24. The gating switch 17 is connected to the first operational amplifier 18, the second operational amplifier 19, the third operational amplifier 20, the first fixed attenuator 21, and the second fixed attenuator 22. The switching circuit 16 signals connect each of the gating switches 17. The gating switches 17 can be, for example, relay-controlled switches. The control circuit 12 signals connect the switching circuit 16 to the first adjustable attenuator 23 and the second adjustable attenuator 24. The switching circuit 16 can control the conduction and disconnection of the gating switches 17 corresponding to the first operational amplifier 18, the second operational amplifier 19, or the third operational amplifier 20 based on signals from the control circuit 12, thereby eliminating the use of the operational amplifier. Switching circuit 16 can control the switching on and off of selector switches 17 corresponding to first and second fixed attenuators 21 and 22 based on signals from control circuit 12, thereby disabling and enabling the fixed attenuators. As shown in FIG4 , first operational amplifier 18, first fixed attenuator 21, second operational amplifier 19, first adjustable attenuator 23, third operational amplifier 20, second adjustable attenuator 24, and second fixed attenuator 22 are sequentially connected. The signal strength at the feed-in end of the leaky cable can be adjusted by adjusting the operational amplifiers, the fixed attenuators, and the attenuation coefficient of the digitally controlled attenuators.

[0081] This embodiment provides a MIMO system for feeding signals into a non-uniformly distributed leaky cable at both ends and a signal strength balancing method of the system. The slotting mode of the outer conductor of the leaky cable is segmented along the length direction of the leaky cable to obtain the characteristics of weak radiation performance at the signal input end but good transmission performance, weak transmission performance at the midpoint O of the leaky cable but strong radiation performance. Under the condition of ensuring that the first feeding end A and the second feeding end B of the leaky cable signal input end meet the communication requirements, the radiation performance is appropriately reduced and the transmission performance is enhanced. The radiation performance is appropriately improved and the transmission performance is weakened at the midpoint O of the leaky cable. A certain radiation performance is sacrificed at the front end section of the communication link to ensure a smaller transmission loss. An appropriate amount of transmission loss is sacrificed at the end section to increase the radiation performance, so that the signal strength of the entire leaky cable section is more balanced, the signal-to-noise ratio of the end signal coverage area is improved, and the quality of leakage communication is improved. A signal controller and a positioning base station are added between the RRU device and the POI, and a positioning base station is used to locate the signal controller. The base station obtains the location information of the mobile terminal, uses the signal controller to calculate the length of the mobile terminal from the first feeding end or the second feeding end of the leaky cable along the extension direction of the leaky cable, and calculates the signal strength difference of the radiation signal of the input signal from the first feeding end and the second feeding end of the leaky cable at the mobile terminal based on the length of the mobile terminal from the first feeding end or the second feeding end of the leaky cable along the extension direction of the leaky cable and the radiation performance information of the leaky cable, compares the signal strength difference with a preset difference threshold, and when the signal strength difference is greater than the preset difference threshold, adjusts the signal strength fed into the first feeding end or the second feeding end so that the signal strength difference of the radiation signal of the input signal from the first feeding end and the second feeding end of the leaky cable received by the mobile terminal is less than the preset difference threshold, thereby controlling the signal strength of the two signals received by the mobile terminal 2 within the processing range of the device, improving the imbalance of the signal strength of the two signals, and improving the signal quality.

[0082] Example 2

[0083] In this embodiment, a MIMO system with unevenly distributed signal feeds at both ends of a leaky cable is provided, wherein the number of leaky cables can be set to more than two, and all leaky cables have the same polarization direction. To ensure more balanced signal strength across the entire leaky cable interval, improve the signal-to-noise ratio in the end signal coverage area, extend the usable distance of the leaky cable, and reduce the number of devices used, the leaky cables are configured with an unevenly distributed slot. Specifically, the slots of each leaky cable are segmented along the length of the cable, and the slot groups within a segment of the leaky cable are arranged identically. The slots within the slot groups in each segment are arranged sequentially along the same radial region along the length of the leaky cable. The per-meter loss constant of each section of the leaky cable between the signal feed end and the midpoint of the leaky cable gradually increases, causing the transmission performance of each section of the leaky cable between the signal feed end and the midpoint of the leaky cable to gradually weaken; the coupling loss of each section of the leaky cable between the signal feed end and the midpoint of the leaky cable gradually decreases, and the radiation performance of each section of the leaky cable between the signal feed end and the midpoint of the leaky cable gradually increases, resulting in the leaky cable exhibiting weak radiation performance at the signal input end of the leaky cable, but strong transmission performance, and weak transmission performance at the midpoint O of the leaky cable, but slightly stronger radiation performance. In addition, to ensure the system loss balance of adjacent leaky cables, the number and length of segments of all leaky cables are consistent. The rest of the content refers to the description in Example 1 and will not be repeated here.

[0084] As shown in FIG5 , a 4×4 MIMO system with signals fed into both ends of a non-uniformly distributed leaky cable is shown. There are two leaky cables, namely the first leaky cable 25 and the second leaky cable 26. The radiation polarization directions of the two leaky cables are the same, for example, both are horizontally polarized leaky cables (they can also be vertically polarized, +45° polarized, -45° polarized), wherein the first leaky cable 25 is divided into three sections from the signal feeding end to the midpoint O of the leaky cable, namely the first section I1, the second section I2, and the third section I3. From the first section I1 to the third section I3, the pitch of the slot group between each section gradually decreases, so that the radiation performance of the leaky cable gradually increases and the transmission performance gradually decreases. For example, the length L1 of the first section I1 is 150m, the loss constant per 100 meters is α1 is 7.3dB / 100m, and the coupling loss is L C1 is 73dB; the length L2 of the second section I2 is 70m, the loss constant per 100m is α2 is 9.2dB / 100m, and the coupling loss is L C2 is 69dB; the length L3 of the second section I3 is 30m, the loss constant per 100m is α3 is 19.8dB / 100m, and the coupling loss is L C3 The arrangement of the slots of the second leaky cable 26 is the same as that of the first leaky cable 25. In this embodiment, the radiation performance of the leaky cable is gradually enhanced and the transmission performance is gradually weakened by setting the pitch of the slots of the leaky cable.

[0085] In some embodiments, as shown in FIG6 , an 8×8 MIMO system with non-uniformly distributed leaky cables feeding signals at both ends thereof has four leaky cables, namely a first leaky cable 25, a second leaky cable 26, a third leaky cable 27, and a fourth leaky cable 28. The radiation polarization directions of the four leaky cables are the same, for example, all are horizontally polarized leaky cables (they can also all be vertically polarized, +45° polarized, or -45° polarized). The segmented arrangement of the first leaky cable 25, the second leaky cable 26, the third leaky cable 27, and the fourth leaky cable 28 is the same as that of the first leaky cable 25 in the above embodiment. The radiation performance of the leaky cables is gradually enhanced, while the transmission performance is gradually weakened. Details will not be given here.

[0086] In this embodiment, preferred polarization directions are vertical polarization, horizontal polarization, +45° polarization, and -45° polarization.

[0087] In other embodiments, the radiation performance of the leaky cable can be gradually enhanced while the transmission performance can be gradually weakened by adjusting at least one parameter of the leaky cable slot hole pitch, slot length, slot width, or slot inclination. The specific method for adjusting the radiation performance is described in Example 1 and will not be repeated here.

[0088] Example 3

[0089] In this embodiment, in order to improve the coherence of signals between leaky cables, a MIMO system is provided in which the signals fed into the two ends of the leaky cables are unevenly distributed, wherein the number of leaky cables can be set to more than two, the radiation polarization directions of all slot groups of the same leaky cable are the same, and the radiation polarization directions of adjacent leaky cables are different. In order to make the signal strength of the entire leaky cable section more balanced, improve the signal-to-noise ratio of the terminal signal coverage area, extend the use distance of the leaky cable, and reduce the number of devices used, the leaky cables are all set to have uneven slot distribution. Specifically, the slots of each leaky cable are segmented along the length of the leaky cable, the slot groups within a section of the leaky cable are arranged in the same manner, and the slots within the slot groups in each section are arranged sequentially along the same radial area position along the length of the leaky cable. The per-meter loss constant of each section of the leaky cable between the signal feed end and the midpoint of the leaky cable gradually increases, causing the transmission performance of each section of the leaky cable between the signal feed end and the midpoint of the leaky cable to weaken; the coupling loss of each section of the leaky cable between the signal feed end and the midpoint of the leaky cable gradually decreases, and the radiation performance of each section of the leaky cable between the signal feed end and the midpoint of the leaky cable gradually increases, resulting in the leaky cable exhibiting weak radiation performance at the signal input end of the leaky cable, but strong transmission performance, and weak transmission performance at the midpoint O of the leaky cable, but slightly stronger radiation performance. In addition, to ensure the system loss balance of adjacent leaky cables, the number and length of segments of all leaky cables are consistent. The rest of the content refers to the description in Example 1 and will not be repeated here.

[0090] As shown in Figure 7, a 4×4 MIMO system with non-uniformly distributed leaky cables feeding signals at both ends is constructed. There are two leaky cables, a first leaky cable 25 and a second leaky cable 26. The two leaky cables have different radiation polarization directions. For example, the first leaky cable 25 is a vertically polarized leaky cable, while the second leaky cable 26 is a horizontally polarized leaky cable. The first leaky cable 25 is divided into three sections from the signal feed end to the cable midpoint O: the first section I1, the second section I2, and the third section I3. The pitch of the slot groups between sections gradually decreases from the first section I1 to the third section I3, thereby gradually enhancing the radiation performance of the leaky cable. The second leaky cable 26 is divided into three sections from the signal feed end to the cable midpoint O: the first section I1, the second section I2, and the third section I3. The pitch of the slot groups between sections gradually decreases from the first section I1 to the third section I3, thereby gradually enhancing the radiation performance of the leaky cable and gradually weakening the transmission performance. In this embodiment, the pitch of the leaky cable slots is adjusted to gradually enhance the radiation performance of the leaky cable and gradually weaken the transmission performance.

[0091] As shown in FIG8 , in some embodiments, to improve signal coherence between leaky cables, an 8×8 MIMO system with unevenly distributed signal feeds at both ends of the leaky cables is provided. The system comprises four leaky cables, namely a first leaky cable 25, a second leaky cable 26, a third leaky cable 27, and a fourth leaky cable 28. Adjacent leaky cables have different radiation polarization directions. For example, the first leaky cable 25 is a vertically polarized leaky cable, the second leaky cable 26 is a horizontally polarized leaky cable, the third leaky cable 27 is a vertically polarized leaky cable, and the fourth leaky cable 28 is a horizontally polarized leaky cable. Each of the first, second, third, and fourth leaky cables 25, 26, 27, and 28 is divided into three sections from the signal feed end to the cable midpoint O: a first section I1, a second section I2, and a third section I3. The pitch of the slot groups between sections gradually decreases from the first section I1 to the third section I3, thereby gradually enhancing the radiation performance of the leaky cables while gradually weakening their transmission performance.

[0092] In this embodiment, preferred polarization directions are vertical polarization, horizontal polarization, +45° polarization, and -45° polarization.

[0093] In other embodiments, the radiation performance of the leaky cable can be gradually enhanced while the transmission performance can be gradually weakened by adjusting at least one parameter of the leaky cable slot hole pitch, slot length, slot width, or slot inclination. The specific method for adjusting the radiation performance is described in Example 1 and will not be repeated here.

[0094] Generally speaking, the performance difference between multiple leaky cables with the same number of segments and lengths arranged side by side is small. The first signal controller or the second signal controller can obtain the location information of the mobile terminal from the positioning base station connected to its signal, and calculate the length of the mobile terminal from the first feeding end and the second feeding end of any leaky cable (which can be defined as the target leaky cable) along the extension direction of the target leaky cable based on the location information, and calculate the signal strength difference of the radiation signal of the input signal of the first feeding end and the second feeding end of the target leaky cable at the mobile terminal based on the length of the mobile terminal from the first end and the second end of the target leaky cable along the extension direction of the target leaky cable and the radiation performance information of the leaky cable length interval of the target leaky cable; in response to the signal strength difference being greater than the preset difference threshold, the first signal controller is used to adjust the signal strength of the first signal fed into the first feeding end of each leaky cable, and the adjustment degree of the first signal fed into each leaky cable can be the same; and / or, the second signal controller is used to adjust the signal strength of the second signal fed into the second feeding end of each leaky cable, and the adjustment degree of the second signal fed into each leaky cable can be the same, so that the signal strength difference is less than or equal to the preset difference threshold. The above adjustment method is highly efficient.

[0095] Of course, in other embodiments, the adjustment process of the corresponding single leaky cable in FIG1 may also be performed for each leaky cable.

[0096] Example 4

[0097] Correspondingly, an embodiment of the present application also provides a signal strength equalization device for a MIMO system in which signals are fed into the two ends of a non-uniformly distributed leaky cable. As shown in FIG9 , the signal strength equalization device 29 includes a position calculation module 31, a signal strength difference calculation module 32, and a signal strength adjustment module 11. In the present application, the positioning base station is set separately, and the position calculation module 31 signal is connected to the first positioning base station 9 (or the second positioning base station 10) to obtain the position information of the mobile terminal from the positioning base station. In some other embodiments, the positioning base station can be integrated into the signal strength equalization device, for example, the signal strength equalization device also includes the first positioning base station 9 (or the second positioning base station 10).

[0098] The position calculation module 31 is used to obtain the position information of the mobile terminal 2 and calculate the distance between the mobile terminal 2 and the first feeding end A or the second feeding end B of the leaky cable along the extension direction of the leaky cable based on the position information. The detailed calculation method is described in the above embodiment and will not be repeated here.

[0099] The signal strength difference calculation module 32 is used to obtain radiation performance information for each length of the leaky cable, including the number of segments and the length of each segment, the loss constant per 100 meters, and the coupling loss. Based on the distance from the mobile terminal 2 to the first feed end A or the second feed end B of the leaky cable along the extension direction of the leaky cable and the radiation performance information, the module calculates the signal strength difference at the mobile terminal between the radiation signals input from the first feed end A and the second feed end B of the leaky cable. The detailed calculation method is described in the above embodiment and will not be repeated here.

[0100] The signal strength adjustment module 11 is configured to adjust the signal strength fed into the first feed-in terminal A or the second feed-in terminal B, based on the signal strength difference being greater than a preset difference threshold, so that the difference in signal strength between the radiation signal input from the first feed-in terminal A and the second feed-in terminal B of the leaky cable received by the mobile terminal 2 is less than the preset difference threshold. The specific structural principles and adjustment methods of the signal strength adjustment module are described in the above embodiments and will not be repeated here.

[0101] This embodiment provides a signal strength equalization device for a MIMO system with unevenly distributed feed signals at both ends of a leaky cable. The device can adjust the signal strength fed to the first feed end A or the second feed end B based on the calculated signal strength difference, thereby equalizing the feed signals at both ends of the leaky cable. This ensures that the difference in signal strength received by a user terminal is less than a preset difference threshold, thereby meeting the processing requirements of the user terminal and ensuring communication quality.

[0102] The above is a detailed introduction to the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for those skilled in the art, according to the idea of ​​the present application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A MIMO system with non-uniformly distributed leaky cable feeding signals at both ends, characterized in that: It includes a first POI, a first signal controller, a first RRU device, a first positioning base station, a second POI, a second signal controller, a second RRU device, a second positioning base station and at least one leaky cable; the first end signal of the leaky cable is connected to the first POI, and the second end signal of the leaky cable is connected to the second POI; the first signal controller signal is connected to the first RRU device, the first positioning base station and the first POI; the second signal controller signal is connected to the second RRU device, the second positioning base station and the second POI; the PCI of the first RRU device and the second RRU device are set to the same; the radiation performance of the two ends of the leaky cable is weaker than that at the midpoint of the leaky cable, but the transmission performance of the two ends of the leaky cable is stronger than that at the midpoint of the leaky cable; The first signal controller or the second signal controller is used to obtain the location information of the mobile terminal from the positioning base station connected to the signal thereof, and calculate the length of the mobile terminal from the first feeding end or the second feeding end of the target leaky cable along the extension direction of the target leaky cable according to the location information, and the target leaky cable belongs to the at least one leaky cable; Acquire radiation performance information of a target leaky cable length interval, the radiation performance information including the number of segments and the length of each segment, a hectare loss constant and a coupling loss, and calculate a signal strength difference at the mobile terminal between radiation signals input from the first feeding end and the second feeding end of the target leaky cable according to the length of the mobile terminal from the first feeding end or the second feeding end of the target leaky cable along the extension direction of the target leaky cable and the radiation performance information; The first signal controller is used to adjust the signal strength fed into the first feeding end of the at least one leaky cable in response to the signal strength difference being greater than a preset difference threshold, and / or the second signal controller is used to adjust the signal strength fed into the second feeding end of the at least one leaky cable in response to the signal strength difference being greater than a preset difference threshold, so that the signal strength difference is less than the preset difference threshold.

2. A MIMO system with non-uniformly distributed leaky cable feeding signals at both ends according to claim 1, characterized in that: The leaky cable is divided into at least two sections from the signal feeding end to the midpoint of the leaky cable, the arrangement of the slot group in the same section of the leaky cable is the same, the slots in the slot group in the same section of the leaky cable are arranged sequentially along the same radial area position in the length direction of the leaky cable, and the loss constant per 100 meters of different sections of the leaky cable from the signal feeding end to the midpoint of the leaky cable gradually increases, and the coupling loss gradually decreases.

3. A MIMO system with non-uniformly distributed leaky cable feeding signals at both ends according to claim 1, characterized in that: The number of the leaky cables is not less than two, and the radiation polarization directions of all slot groups of the same leaky cable are the same; the polarization directions of all the leaky cables are the same, and the number and length of segments of all the leaky cables are consistent.

4. A MIMO system with non-uniformly distributed leaky cable feeding signals at both ends according to claim 1, characterized in that: The number of the leaky cables is not less than two, the radiation polarization directions of all slot groups of the same leaky cable are the same, the radiation polarization directions of adjacent leaky cables are different, and the number and length of segments of all leaky cables are consistent.

5. A MIMO system with non-uniformly distributed leaky cable feeding signals at both ends according to claim 1, characterized in that: The first signal controller and the second signal controller both include a signal strength adjustment module, which includes a control circuit, an attenuator, and an amplifier. The control circuit signal is connected to the attenuator or the amplifier, and the attenuator and the amplifier are connected in series.

6. A MIMO system with non-uniformly distributed leaky cable two-end feed signals as claimed in claim 5, characterized in that: The signal strength adjustment module further includes a switching circuit and a gate switch, wherein the gate switch is connected in parallel to both ends of the attenuator or amplifier, and the switching circuit signal is connected to the gate switch and can control the conduction and disconnection of the gate switch.

7. A signal strength equalization method for a MIMO system with non-uniformly distributed leaky cable feed signals at both ends, characterized in that: The steps include: Set the PCI of the RRU devices at both ends of the leaky cable to be the same; Acquire the location information of the mobile terminal, and calculate the distance of the mobile terminal from the first feeding end or the second feeding end of the leaky cable along the extension direction of the leaky cable according to the location information; Acquire radiation performance information of the length interval of the leaky cable, the radiation performance information including the number of segments and the length of each segment, the loss constant per hundred meters and the coupling loss, and calculate the signal strength difference of the radiation signal of the input signal of the first feeding end and the second feeding end of the leaky cable at the mobile terminal according to the length of the mobile terminal from the first feeding end or the second feeding end of the leaky cable along the extension direction of the leaky cable and the radiation performance information; According to the signal strength difference being greater than a preset difference threshold, the signal strength fed into the first feeding end or the second feeding end is adjusted so that the signal strength difference is less than the preset difference threshold.

8. A signal strength equalization method for a MIMO system with non-uniformly distributed leaky cable feed signals at both ends according to claim 7, characterized in that: Calculating the signal strength difference comprises the steps of: Calculate a first transmission loss of a signal fed from the first feeding end to the mobile terminal according to the length of the mobile terminal from the first feeding end of the leaky cable along the extension direction of the leaky cable, the length of each segment between the mobile terminal and the first feeding end, and the hectare-meter loss constant of each segment; According to the distance between the mobile terminal and the second feeding end of the leaky cable along the extending direction of the leaky cable, the distance between the mobile terminal and the second feeding end of the leaky cable The length of each segment between the two feeding ends and the hectare-meter loss constant of each segment are used to calculate the second transmission loss of the signal fed from the second feeding end to the mobile terminal; The absolute value of the difference between the first transmission loss and the second transmission loss is used as the signal strength difference.

9. The signal strength equalization method of a MIMO system with non-uniformly distributed leaky cable feed signals at both ends according to claim 7, characterized in that: The step of adjusting the signal strength fed into the first feeding end or the second feeding end comprises: The strength of the feed signal at the end of the leaky cable that is close to the mobile terminal along the length direction is attenuated, or the strength of the feed signal at the end of the leaky cable that is far from the mobile terminal along the length direction is amplified.

10. The signal strength equalization method of a MIMO system with non-uniformly distributed leaky cable feed signals at both ends as described in claim 7, characterized in that: The preset difference threshold does not exceed 20dB.

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