Antenna calibration method and system

Abstract

The present application discloses an antenna calibration method and system for the field of communication technology. The system includes: a baseband processing unit, a radio frequency remote unit, an antenna array, and a coupling antenna; the antenna array is configured to send a radio frequency calibration signal sent by the baseband processing unit to a wireless network; or to receive a radio frequency calibration signal; the radio frequency remote unit is configured to provide multiple transmission channels; the multiple transmission channels correspond to the multiple transmission ports; the coupling antenna is configured to receive the radio frequency calibration signal sent by the baseband processing unit in the wireless network and transmit a coupling signal corresponding to the radio frequency calibration signal to the baseband processing unit; or to send the radio frequency calibration signal to the wireless network; the baseband processing unit is configured to calibrate multiple baseband signals to be transmitted corresponding to the multiple transmission channels based on the difference between the radio frequency calibration signal and the coupling signal.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of communication technology, and in particular to an antenna calibration method and system. Background Art

[0002] With the development of communication technology, RF systems have higher requirements for the accuracy of wavelength division shaping. At the same time, in multi-user, multi-input, multi-output wireless communication systems, each channel must be calibrated to eliminate the impact of deviations between the RF receive and transmit channels on the channel. Ultimately, the RF transmit channel amplitude and phase consistency of multiple remote radio units (RRUs) is achieved. This ensures that the RF signals transmitted through multiple RF transmit channels remain consistent, improving the transmission performance of the RF signals.

[0003] Currently, antenna calibration is generally performed using a calibration board. One end of the calibration board is connected to the RRU, and the other end is connected to the RF antenna. The RRU provides multiple transmission channels and calibration channels. During the calibration process, the baseband unit (BBU) sends a calibration sequence to the calibration board through the signal channel within the RRU. After receiving the signal corresponding to the calibration sequence, the calibration board couples the signal so that it is transmitted back to the BBU through the signal channel within the RRU. The BBU then compares the coupled signal with the original transmitted signal and calibrates each transmission channel based on the difference to determine the consistency of the transmission channels.

[0004] Since this calibration method requires the participation of a calibration board, for example, multiple ports of a frequency band share one calibration board, and multiple frequency bands require multiple calibration boards. Since the calibration board needs to be placed inside the antenna, it will bring great difficulties to the layout inside the RF device. At the same time, since the calibration board is installed between the RRU and the RF antenna, it is impossible to calibrate the phase difference and amplitude difference caused by the radiating unit in the RF antenna, which will reduce the calibration accuracy. Therefore, how to improve the accuracy of antenna calibration and simplify the structure of the RF device has become an urgent problem that needs to be solved. Summary of the Invention

[0005] An embodiment of the present application provides an antenna calibration system and method, which is used to feed back a coupled signal corresponding to a radio frequency calibration signal to a baseband processing unit via a coupled antenna, and finally calibrate the baseband signal corresponding to each transmission channel based on the difference between the radio frequency calibration signal and the coupled signal. In this way, the antenna calibration process can be completed without the design of a calibration board, which simplifies the layout of the antenna system and reduces costs.

[0006] A first aspect of an embodiment of the present application provides an antenna calibration system, including:

[0007] The antenna calibration system includes a baseband processing unit, a radio frequency remote unit, an antenna array and a coupling antenna; wherein the baseband processing unit is connected to the first end of the radio frequency remote antenna, and the antenna array is connected to the second end of the radio frequency remote unit to form a serial structure; then the coupling antenna is connected to the second end of the radio frequency remote unit; wherein the antenna array and the coupling antenna can both be used to send radio frequency calibration signals to the wireless network, or receive coupling signals corresponding to the radio frequency calibration signals from the wireless network, and transmit the coupling signals to the baseband processing unit; the radio frequency remote unit is the "connection bridge" between the baseband processing unit and the antenna, used to provide multiple transmission channels; the baseband processing unit sends radio frequency calibration signals, receives coupling signals corresponding to the radio frequency calibration signals, and perceives the signal loss caused by different transmission channels by comparing the difference between the radio frequency calibration signals and the coupling signals, and then calibrates the radio frequency signals to be sent on each transmission channel in advance based on the difference to eliminate the influence of the transmission channel itself on the radio frequency signal.

[0008] In the above embodiment, the baseband processing unit transmits a radio frequency calibration signal via the transmission channel in the radio remote unit and then couples the RF calibration signal back to the baseband processing unit. Through the transmission of the RF calibration signal, the baseband processing unit can sense the impact of the transmission channel on the RF calibration signal. This allows the baseband processing unit to pre-compensate the transmitted RF signal based on the difference between the initial RF calibration signal and the coupled signal, reducing signal loss caused by the transmission channel, ensuring the uniformity of RF signals transmitted across different channels, and improving RF signal transmission performance. Furthermore, this method achieves signal coupling without the need for a calibration board, simplifying the antenna system layout and reducing costs.

[0009] In an optional embodiment, the multiple transmission channels provided by the radio frequency remote unit can be divided into multiple signal transmission channels and at least one calibration channel; then the antenna array is connected to the multiple signal transmission channels, that is, the multiple transmission ports corresponding to the antenna array are connected to the multiple signal transmission channels; the coupling antenna is connected to the calibration channel, that is, the coupling antenna corresponds to at least one calibration channel.

[0010] In the above embodiment, the antenna array is connected to the signal transmission channel, and the coupled antenna is connected to the calibration channel, so that the RF calibration signal can be sent by the antenna array, received by the coupled antenna and returned to the baseband processing unit; or sent by the coupled antenna, received by the antenna array and returned to the baseband processing unit through the signal transmission channel, so that the RF calibration signal can not only calibrate the downlink signal, but also calibrate the uplink signal, thereby improving the calibration performance of the antenna calibration system.

[0011] In an optional embodiment, when the antenna calibration system performs downlink signal calibration, the baseband processing unit sends a radio frequency calibration signal through a signal transmission channel, which is then transmitted to the wireless network by the antenna array; the coupling antenna receives the radio frequency calibration signal from the wireless network, then couples the radio frequency calibration signal to the calibration channel, and transmits the coupled signal of the radio frequency calibration signal to the baseband processing unit through the calibration channel.

[0012] In this embodiment, the transmission direction of the RF calibration signal in the signal transmission channel is consistent with the transmission direction of the downlink signal. In this way, the impact of the signal transmission channel on the downlink signal can be perceived through the signal change of the RF calibration signal. Then, the baseband processing unit can perform signal compensation on the downlink signal in advance according to the difference between the coupling signal and the RF calibration signal, thereby improving the transmission performance of the downlink signal.

[0013] In an optional embodiment, when the antenna calibration system performs uplink signal calibration, the baseband processing unit sends a radio frequency calibration signal through the calibration channel, which is transmitted to the wireless network by the coupled antenna; then the antenna array receives the radio frequency calibration signal from the wireless network, couples the radio frequency calibration signal to the signal transmission channel, and transmits the coupled signal of the radio frequency calibration signal to the baseband processing unit through the signal transmission channel.

[0014] In this embodiment, the transmission direction of the RF calibration signal in the signal transmission channel is consistent with the transmission direction of the uplink signal, so that the impact of the signal transmission channel on the uplink signal can be perceived through the signal change of the RF calibration signal. Then, the baseband processing unit can perform signal compensation on the uplink signal in advance based on the difference between the coupling signal and the RF calibration signal, thereby improving the transmission performance of the uplink signal.

[0015] In an optional embodiment, the antenna calibration system also includes a digital phase shifter, which is located between the coupling antenna and the calibration channel. The coupling antenna is connected to one end of the digital phase shifter, and the port of the calibration channel is connected to the other end of the digital phase shifter. The digital phase shifter is used to offset the influence of factors such as the phase shifter in the antenna and the position distribution between the antenna and the coupling antenna on the phase of the RF calibration signal; in this way, the phase difference between the coupling signal and the RF calibration signal basically comes from the influence of the signal transmission channel, so that the RF signal to be transmitted can be calibrated more accurately, thereby improving the calibration accuracy.

[0016] In an optional embodiment, the number of coupled antennas can be the same as the number of calibration channels in the radio frequency remote unit, so that each coupled antenna corresponds to a unique calibration channel. When the antenna calibration system is used for downlink signal calibration, each coupled antenna will receive the radio frequency calibration signal, and then each coupled signal will be transmitted to the baseband processing unit through the calibration channel.

[0017] In an optional embodiment, the number of coupled antennas may also be greater than the number of calibration channels in the radio frequency remote unit. In this case, the antenna calibration system includes a combiner. When the antenna calibration system is used for downlink signal calibration, each coupled signal corresponding to each coupled antenna is converged into one coupled signal by the combiner and then transmitted to the baseband processing unit through the calibration channel. In this way, the signal-to-noise ratio of the coupled signal can be improved and the calibration accuracy can be improved.

[0018] A second aspect of an embodiment of the present application provides an antenna calibration method, including:

[0019] Receiving a radio frequency calibration signal in a wireless network through a coupled antenna; wherein the radio frequency calibration signal is sent to the wireless network by a baseband processing unit through a transmission channel in a radio remote unit;

[0020] transmitting the coupled signal corresponding to the radio frequency calibration signal back to the baseband processing unit through the transmission channel;

[0021] A plurality of to-be-transmitted baseband signals in the baseband processing unit are calibrated according to a difference between the coupled signal and the radio frequency calibration signal.

[0022] In an optional embodiment, the transmission channel includes multiple signal transmission channels and at least one calibration channel, and the coupling antenna is connected to the at least one calibration channel.

[0023] In an optional embodiment, when the RF calibration signal is sent by the baseband processing unit to the wireless network through the multiple signal transmission channels, the coupling signal corresponding to the RF calibration signal is transmitted to the baseband processing unit through the transmission channel, including: transmitting the coupling signal corresponding to the RF calibration signal to the baseband processing unit through the at least one calibration transmission channel.

[0024] In an optional embodiment, when the RF calibration signal is sent by the baseband processing unit to the wireless network through the at least one calibration channel, the coupling signal corresponding to the RF calibration signal is transmitted to the baseband processing unit through the transmission channel, including: transmitting the coupling signal corresponding to the RF calibration signal to the baseband processing unit through the multiple transmission channels.

[0025] In an optional embodiment, the method further comprises:

[0026] The phase of the coupled signal is adjusted by a digital phase shifter according to the phase information of the radio frequency calibration signal; wherein the digital phase shifter is located between the coupled antenna and the at least one calibration channel.

[0027] In an optional embodiment, calibrating the multiple baseband signals to be transmitted in the baseband processing unit includes: calibrating the phases and amplitudes of the multiple baseband signals to be transmitted in the baseband processing unit.

[0028] A third aspect of the present application provides a control device comprising: at least one processor and a memory, wherein the memory stores computer-executable instructions that can be run on the processor, and when the computer-executable instructions are executed by the processor, the control device executes the method described in the second aspect or any possible implementation of the second aspect.

[0029] In a fourth aspect, the present application provides a chip or chip system, the chip or chip system including at least one processor and a communication interface, the communication interface and the at least one processor being interconnected via a line, the at least one processor being configured to run a computer program or instruction to perform the antenna calibration method described in any one of the second aspect to any one of the possible implementations of the second aspect;

[0030] The communication interface in the chip may be an input / output interface, a pin or a circuit, etc.

[0031] In one possible implementation, the chip or chip system described above in this application further includes at least one memory, in which instructions are stored. The memory may be a storage unit within the chip, such as a register, a cache, etc., or a storage unit of the chip (e.g., a read-only memory, a random access memory, etc.).

[0032] A fifth aspect of an embodiment of the present application provides a computer-readable storage medium, which stores a computer program. When the computer-readable storage medium is run on a computer, the computer executes the antenna calibration method described in any one of the second aspects to the second aspect.

[0033] A sixth aspect of an embodiment of the present application provides a computer program product, which includes computer software instructions. The computer software instructions can be loaded by a processor to implement the process in any one of the antenna calibration methods in the second aspect above.

[0034] It can be seen from the above technical solutions that the embodiments of the present application have the following advantages:

[0035] In the technical solution provided by the embodiment of the present application, the baseband processing unit transmits a radio frequency calibration signal through the transmission channel in the radio frequency remote unit, and then couples the radio frequency calibration signal back to the baseband processing unit. In this way, the baseband processing unit can use the transmission of the radio frequency calibration signal to perceive the impact of the transmission channel on the radio frequency calibration signal. Then, based on the difference between the initial radio frequency calibration signal and the coupled signal, it can pre-compensate the radio frequency signal to be transmitted, thereby reducing the signal loss caused by the transmission channel, ensuring the uniformity of radio frequency signals transmitted through different channels, and improving the transmission performance of radio frequency signals. At the same time, this method can achieve signal coupling without the need for a calibration board, simplifying the layout of the antenna system and reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A network architecture diagram of an antenna calibration system provided in an embodiment of the present application;

[0037] Figure 2 A diagram showing the internal structure of a base station antenna provided in an embodiment of the present application;

[0038] Figure 3 A network architecture diagram of another antenna calibration system provided in an embodiment of the present application;

[0039] Figure 4 A schematic diagram of a flow chart of an antenna calibration method provided in an embodiment of the present application;

[0040] Figure 5 A schematic diagram of the structure of a control device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0041] An embodiment of the present application provides an antenna calibration system and method, which is used to feed back a coupled signal corresponding to a radio frequency calibration signal to a baseband processing unit via a coupled antenna, and finally calibrate the baseband signal corresponding to each transmission channel based on the difference between the radio frequency calibration signal and the coupled signal. In this way, the antenna calibration process can be completed without the design of a calibration board, which simplifies the layout of the antenna system and reduces costs.

[0042] The technical solutions in this application will be described in detail below in conjunction with the drawings in this application. Obviously, the described embodiments are only part of the embodiments of this application, rather than all the embodiments.

[0043] The terms "first," "second," "third," "fourth," and the like (if any) in the specification and claims of this application and in the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a particular order or sequential sequence. It should be understood that the terms used in this manner are interchangeable where appropriate so that the embodiments described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "including" and "having," and any variations thereof, are intended to cover non-exclusive inclusions, e.g., a process, method, system, product, or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0044] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application.

[0045] In the field of mobile communications, to address issues such as difficult network site selection, inconvenient networking, and high costs, current wireless communications networks often use a multi-channel coverage approach consisting of a baseband processing unit (BBU) and a radio remote unit (RRU). The BBU and RRU are connected via optical fiber, and each BBU can be connected to multiple RRUs. The BBU processes various communication signals, while the RRU provides multiple transmission channels.

[0046] Based on the above structure, when the base station sends a downlink signal, since the BBU is directly connected to the RRU via optical fiber, the base station can control the downlink signal to be transmitted from a specific RRU channel. When the base station receives an uplink signal, the uplink signal sent by the sender is received by the nearest RRU channel and then transmitted to the BBU through an independent RRU channel. In this way, the interference of other signals on the uplink signal can be greatly reduced.

[0047] The other end of the RRU is connected to an antenna, which is used to radiate downlink signals to the wireless communication network or receive uplink signals in the wireless communication network. With the development of 5G technology, 5G base stations can support large-scale antenna arrays and use beamforming technology to improve the transmission quality of wireless signals in space. In order to improve the accuracy of beamforming, the errors caused by the characteristics of multiple RRU channels must be within the accuracy range. Therefore, periodic calibration can be used to reduce the errors caused by the differences in RRU channels.

[0048] Figure 1 A network architecture diagram of an antenna calibration system provided in an embodiment of the present application; Figure 1As shown, the antenna calibration system includes a BBU, an RRU, a calibration board and an antenna array; the BBU and the RRU are connected by an optical fiber, and the other end of the RRU is connected to the antenna array. A calibration board (coupling board) is present between the RRU and the antenna array for coupling radio frequency signals to the BBU, and the transmission channel in the RRU is divided into a signal transmission channel and a calibration channel.

[0049] When the antenna calibration system performs downlink signal calibration, the BBU sends a downlink calibration sequence (RF calibration signal) to the RRU. The signal is then transmitted through the signal transmission channel in the RRU to the calibration board, and then coupled by the calibration board and transmitted back from the calibration channel to the baseband. The baseband compares the difference between the initial downlink calibration sequence and the returned calibration sequence (coupled signal) to determine the changes in signal phase and amplitude caused by the signal transmission channel. Finally, the changes corresponding to each signal receiving channel are obtained to compensate for the RF signal to be transmitted corresponding to each signal transmission channel, so as to achieve the purpose of calibrating each signal receiving channel.

[0050] Exemplarily, the RRU includes three signal transmission channels. When a downlink calibration sequence is sent to signal transmission channel 1 and a coupling sequence corresponding to the downlink calibration sequence is finally obtained, the BBU finds out by comparing the differences that signal transmission channel 1 causes a phase shift of 20 degrees in the downlink calibration sequence. Then, when the BBU sends a baseband signal through signal transmission channel 1, it is necessary to adjust the phase of the baseband signal by 20 degrees to reduce the phase error brought to the baseband signal by signal transmission channel 1 itself.

[0051] When the antenna calibration system performs uplink signal calibration, the BBU sends an uplink calibration sequence (RF calibration signal) to the RRU, which is then transmitted through the calibration channel in the RRU to the calibration board. Then, it is coupled by the calibration board and transmitted back from the signal transmission channel to the baseband. The baseband compares the difference between the initial uplink calibration sequence and the returned calibration sequence (coupled signal) to find out the changes in signal phase and amplitude caused by the signal transmission channel, and finally obtains the corresponding changes in each signal receiving channel to compensate for the RF signal received by each signal transmission channel. It can be understood that the principles of the uplink signal calibration process and the downlink signal calibration process are similar, except that the direction of the calibration sequence in the signal transmission channel is changed, which will not be elaborated here.

[0052] As shown in the figure above, the calibration process of this antenna calibration system is primarily based on the coupling function of the calibration board. Calibration accuracy depends on the accuracy of the calibration board. In complex multi-band antenna applications, a large number of calibration boards will be required, making the internal device layout of the system extremely difficult and costly. Furthermore, because the calibration board is located between the RRU and the antenna, the calibration sequence is coupled back to the BBU before being transmitted to the antenna. Therefore, the phase error introduced by the antenna cannot be calibrated, resulting in low calibration accuracy.

[0053] Based on the above problems, an embodiment of the present application provides a new antenna calibration system, which uses an added calibration antenna to replace the calibration board to return the coupled signal, reducing the difficulty of device layout within the system. At the same time, it can also calibrate the phase offset error caused by the antenna, thereby improving the calibration performance of the antenna calibration system and thereby improving the transmission performance of the RF signal.

[0054] The embodiment of the present application is applied to a base station antenna feed system, which is a system consisting of a base station antenna, feeder line, mast, antenna adjustment bracket, etc. Specifically, Figure 2 This is a diagram of the internal structure of a base station antenna provided in an embodiment of the present application; Figure 2 As shown in the figure, a base station antenna generally consists of a radiation unit, a feeding network, a radome and other parts.

[0055] The radiating unit can also be called an antenna vibrator, vibrator, etc.; it is the basic power source of the antenna array, which can effectively radiate outward or receive radio waves (wireless signals) within the team.

[0056] The feed network feeds baseband signals to the radiating elements at a specific amplitude and phase, or transmits received wireless signals to the base station's signal processing unit at a specific radiation and phase. The feed network typically consists of controlled impedance transmission lines and includes components such as phase shifters, combiners, and filters. The RF system controls the phase shifters in the antenna array to adjust the phase of the baseband signal corresponding to each antenna, ultimately controlling the downtilt angle of the entire RF network.

[0057] The radome is used to protect the internal components of the antenna from the influence of the external environment. In order to improve the transmission performance of wireless signals, the radome generally has good electromagnetic wave penetration characteristics and good mechanical properties.

[0058] It is understood that the antenna may also include other components, such as a reflector, to improve the antenna signal's reception sensitivity and focus the reflected signal at the receiving point. This not only greatly enhances the antenna's reception / transmission capabilities but also blocks and shields the received signal from interference from other radio waves coming from behind (in the opposite direction).

[0059] Figure 3 This is a network architecture diagram of another antenna calibration system provided in an embodiment of the present application; Figure 3 As shown, the antenna calibration system uses a coupling antenna instead of a calibration board. The antenna calibration system includes a BBU, an RRU, an antenna array, and a coupling antenna. The BBU and the RRU are connected via an optical fiber, and the other end of the RRU is connected to the antenna array. The coupling antenna is also connected to the RRU via an optical fiber.

[0060] Among them, the transmission channel in the RRU is divided into a signal transmission channel and a calibration channel. The antenna array is connected to the signal transmission channel in the RRU, and the coupling antenna is connected to the calibration channel.

[0061] In an optional embodiment, the number of antenna arrays is the same as the number of signal transmission channels. For example, a row of antennas with the same polarization direction corresponds to one signal transmission channel. Figure 3 There are four rows of antennas, which correspond to the four signal transmission channels in the RRU. The first and third rows of antennas have the same polarization direction, and the second and fourth rows of antennas have the same polarization direction. Each row of antennas corresponds to a signal transmission interface for receiving or sending RF signals.

[0062] The RRU will also include at least one calibration channel, and the number of coupled antennas is not limited here; illustratively, the number of calibration channels can be the same as the number of coupled antennas, so that each coupled antenna can be connected to one of the calibration channels, that is, the coupled antennas and the calibration channels correspond one to one; illustratively, there can be multiple coupled antennas, and the RRU only includes one calibration channel, then multiple coupled antennas can be connected to the calibration channel through a combiner, that is, the coupled antennas can correspond one to one to the calibration channel, or can be many to one, with no specific limitation; it can be understood that using multiple coupled antennas to receive RF calibration signals, and then combining the multiple RF calibration signals into one channel coupled back to the calibration channel can improve the signal-to-noise ratio of the signal, thereby improving the calibration accuracy.

[0063] In an optional embodiment, a digital phase shifter may also be included between the coupling antenna and the calibration channel. The digital phase shifter is used to offset the effect of the phase shifter in the antenna on the calibration. Because the function of the phase shifter in the antenna is to change the downtilt angle of the RF system, it is not the phase error offset caused by the transmission channel in the RF system. Therefore, during calibration, it is necessary to exclude the effect of the phase shifter on the phase so that the baseband signal can be calibrated more accurately.

[0064] The coupling antennas may be arranged along a vertical plane, and the phase compensation of the digital phase shifter connected to the coupling antennas is related to the position of the coupling antennas; for example, Figure 3 As shown, for a row of antennas arranged along a vertical plane, the placement of the coupled antennas determines the strength of the RF signal transmitted by their receiving antennas. For example, coupled antenna P3 is closest to antenna X in the first row of antennas. Therefore, the phase shift of the phase shifter corresponding to antenna X has the greatest impact on the phase shift of the digital phase shifter connected to P3. For example, if the phase shift of the RF signal received by antenna X is a1, the phase shift of the digital phase shifter connected to antenna P3 is -a1.

[0065] It is understandable that each column of antennas can independently correspond to a coupling antenna, or all antennas can share a coupling antenna. Again, there is no limitation. A preferred implementation is that the antenna array corresponding to every two output transmission ports corresponds to a group of coupling antennas.

[0066] Based on the above-mentioned antenna calibration system, when the antenna calibration system performs downlink signal calibration, the BBU sends a downlink calibration sequence (RF calibration signal) to the RRU, which is then transmitted through the signal transmission channel in the RRU to the antenna array corresponding to the transmission channel, and then radiated to the wireless communication network by the signal transmission port corresponding to the antenna array; then the coupling antenna receives the downlink calibration sequence from the wireless communication network, performs phase adjustment on the received downlink calibration sequence, and then transmits it back from the calibration channel to the baseband processing unit. The baseband processing unit compares the difference between the initial downlink calibration sequence and the returned calibration sequence (coupling signal) to obtain the changes in the signal phase and amplitude caused by the signal transmission channel, and finally obtains the changes corresponding to each signal receiving channel to compensate for the RF signal to be transmitted corresponding to each signal transmission channel, so as to achieve the purpose of calibrating each signal receiving channel.

[0067] When the antenna calibration system performs uplink signal calibration, the BBU sends an uplink calibration sequence to the RRU. This sequence is then transmitted through the calibration channel in the RRU to the digital phase shifter. The digital phase shifter first performs advance phase compensation on the uplink calibration sequence to offset the phase shift of the phase shifter corresponding to the antenna. The phase-compensated signal is then sent to the wireless access network via the coupled antenna. The antenna then receives the downlink calibration sequence from the wireless access network and transmits it back to the baseband processing unit via the signal transmission channel. The baseband processing unit compares the difference between the initial uplink calibration sequence and the returned calibration sequence (coupled signal) to determine the changes in signal phase and amplitude caused by the signal transmission channel. Finally, the changes corresponding to each signal receiving channel are obtained to compensate for the RF signal received by each signal transmission channel. It can be understood that the principles of the uplink signal calibration process are similar to those of the downlink signal calibration process, except that the direction of the calibration sequence in the signal transmission channel is changed. This will not be elaborated here.

[0068] Figure 4 A schematic diagram of a flow chart of an antenna calibration method provided in an embodiment of the present application; Figure 4 As shown, the antenna calibration method includes:

[0069] 401. A baseband processing unit sends a radio frequency calibration signal through a transmission channel in a radio remote unit.

[0070] In the antenna calibration system, the baseband processing unit is connected to one end of the radio frequency remote unit, and the antenna array and coupled antenna are respectively connected to the other end of the radio frequency remote unit; among them, the baseband processing unit is used to process the radio frequency signal, the antenna array and coupled antenna are used to send or receive radio frequency signals, and the radio frequency remote unit is used to provide a transmission channel.

[0071] Exemplarily, the transmission channel provided by the radio frequency remote unit may include multiple signal transmission channels and at least one calibration channel, the signal transmission channel is used to connect to the antenna array, and the calibration signal is used to connect to the coupling antenna; when performing downlink signal calibration, the baseband processing unit sends the radio frequency calibration signal through the signal transmission channel and the antenna array; when performing uplink signal calibration, the baseband processing unit sends the radio frequency calibration signal to the wireless network through the calibration channel and the coupling antenna.

[0072] 402. Receive a radio frequency calibration signal in a wireless network.

[0073] When performing antenna calibration, the transmitted RF calibration signal needs to be coupled to the baseband processing unit; it can be understood that when performing downlink signal calibration, the baseband processing unit sends the RF calibration signal to the wireless network through the signal transmission channel and the antenna array, and then the RF calibration signal in the wireless network is received by the coupled antenna; when performing uplink signal calibration, the baseband processing unit sends the RF calibration signal to the wireless network through the calibration channel and the coupled antenna, and then the RF calibration signal in the wireless network is received by the antenna array.

[0074] 403. Transmit the coupled signal corresponding to the radio frequency calibration signal back to the baseband processing unit through the transmission channel.

[0075] After receiving the RF calibration signal from the wireless network, the coupled signal corresponding to the RF calibration signal needs to be transmitted back to the baseband processing unit via the transmission channel. As you can understand, there is also a digital phase shifter between the coupling antenna and the calibration channel. This digital phase shifter is used to pre-compensate the phase of the RF calibration signal or adjust the phase of the coupled signal. Its purpose is to eliminate the influence of the position of the antenna or coupling antenna on the phase of the RF calibration signal. In this way, the phase change of the coupled signal mainly comes from the signal transmission channel itself, improving the accuracy of the calibration.

[0076] 404. The baseband processing unit calibrates a plurality of baseband signals to be transmitted in the baseband processing unit according to a difference between the coupling signal and the radio frequency calibration signal.

[0077] The baseband processing unit compares the difference between the initial RF calibration signal and the returned coupled signal to determine the changes in signal phase and amplitude caused by the signal transmission channel. Finally, it obtains the changes corresponding to each signal receiving channel to compensate for the RF signal to be transmitted corresponding to each signal transmission channel, thereby achieving the purpose of calibrating each signal receiving channel.

[0078] See also Figure 5 , is a structural diagram of a control device 500 provided in an embodiment of the present application, and the control device 500 includes: a processor 501, a memory 502, and a communication interface 503.

[0079] The processor 501, memory 502, and communication interface 503 are interconnected via a bus; the bus may be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 5 Only one thick line is used in the diagram, but this does not mean that there is only one bus or one type of bus.

[0080] The memory 502 may include volatile memory, such as random-access memory (RAM); the memory may also include non-volatile memory, such as flash memory, a hard disk drive (HDD) or a solid-state drive (SSD); the memory 502 may also include a combination of the above types of memory.

[0081] The processor 501 may be a central processing unit (CPU), a network processor (NP), or a combination of a CPU and an NP. The processor 501 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The PLD may be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof.

[0082] The communication interface 503 may be a wired communication interface, a wireless communication interface, or a combination thereof. For example, the wired communication interface may be an Ethernet interface. The Ethernet interface may be an optical interface, an electrical interface, or a combination thereof. The wireless communication interface may be a WLAN interface, a cellular network communication interface, or a combination thereof.

[0083] The processor 501 is used to run the computer program or instructions in the memory 502 to perform Figure 4 The steps of the antenna calibration method in any possible implementation of the illustrated embodiment.

[0084] The processor 501 is used to run the computer program or instructions in the memory 502 to perform Figure 1 The steps performed by the target end in any possible implementation of the illustrated embodiment.

[0085] The embodiment of the present application also provides a chip or chip system, which includes at least one processor and a communication interface, the communication interface and the at least one processor are interconnected through a line, and the at least one processor is used to run a computer program or instruction to perform Figure 5 An antenna calibration method as described in any one of any possible implementations of the illustrated embodiment;

[0086] The communication interface in the chip may be an input / output interface, a pin or a circuit, etc.

[0087] In one possible implementation, the chip or chip system described above in this application further includes at least one memory, in which instructions are stored. The memory may be a storage unit within the chip, such as a register, a cache, etc., or a storage unit of the chip (e.g., a read-only memory, a random access memory, etc.).

[0088] An embodiment of the present application further provides a computer storage medium for storing computer software instructions for use with the aforementioned control device, including instructions for executing a program designed for the control device.

[0089] An embodiment of the present application further provides a computer program product, which includes computer software instructions. The computer software instructions can be loaded by a processor to implement the above-mentioned process in an antenna calibration method.

[0090] In the above embodiments, all or part of the embodiments may be implemented by software, hardware, firmware, or any combination thereof. When implemented by software, all or part of the embodiments may be implemented in the form of a computer program product.

[0091] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0092] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0093] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0094] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0095] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, read-only memory), random access memory (RAM, random access memory), disk or optical disk, and other media that can store program code.

Claims

1. An antenna calibration system, characterized in that: The antenna calibration system includes: a baseband processing unit, a radio frequency remote unit, an antenna array and a coupling antenna; The baseband processing unit is connected to the first end of the radio remote unit; the antenna array and the coupling antenna are connected to the second end of the radio remote unit respectively; The radio remote unit is configured to provide multiple transmission channels; the multiple transmission channels correspond to the multiple transmission ports of the antenna array; The baseband processing unit is configured to send a radio frequency calibration signal through the transmission channel of the radio remote unit; The antenna array is used to send the radio frequency calibration signal sent by the baseband processing unit to the wireless communication network; The coupling antenna is configured to receive the radio frequency calibration signal sent by the baseband processing unit through the antenna array in the wireless communication network, and transmit a coupling signal corresponding to the radio frequency calibration signal to the baseband processing unit; The baseband processing unit is further configured to calibrate the multiple baseband signals to be transmitted corresponding to the multiple transmission channels according to the difference between the radio frequency calibration signal and the coupling signal.

2. The antenna calibration system according to claim 1, wherein: The multiple transmission channels include multiple signal transmission channels and at least one calibration channel; wherein the multiple transmission ports correspond to the multiple signal transmission channels, and the coupling antenna corresponds to the at least one calibration channel.

3. The antenna calibration system according to claim 2, wherein: The baseband processing unit is used to send the radio frequency calibration signal through the multiple signal transmission channels; The coupling antenna is used to couple the radio frequency calibration signal to the calibration channel, and transmit a coupling signal corresponding to the radio frequency calibration signal to the baseband processing unit through the calibration channel.

4. The antenna calibration system according to claim 2 or 3, characterized in that: The antenna calibration system further includes a digital phase shifter, and the coupled antenna is connected to the calibration port via the digital phase shifter.

5. The antenna calibration system according to claim 4, characterized in that: The number of the coupling antennas is equal to the number of the calibration channels; Each coupling signal corresponding to each coupling antenna is transmitted to the baseband processing unit through a calibration channel respectively.

6. The antenna calibration system according to claim 4, characterized in that The antenna calibration system further includes a combiner, the number of coupled antennas is greater than the number of calibration channels, and the antenna calibration system includes one calibration channel; Each coupling signal corresponding to each coupling antenna is aggregated into one coupling signal by the combiner and then transmitted to the baseband processing unit through the calibration channel.

7. An antenna calibration system, characterized in that: The antenna calibration system includes: a baseband processing unit, a radio frequency remote unit, an antenna array and a coupling antenna; The baseband processing unit is connected to the first end of the radio remote unit; the antenna array and the coupling antenna are connected to the second end of the radio remote unit respectively; The radio remote unit is configured to provide multiple transmission channels; the multiple transmission channels correspond to the multiple transmission ports of the antenna array; The baseband processing unit is configured to send a radio frequency calibration signal through the transmission channel of the radio remote unit; The coupling antenna is used to send the radio frequency calibration signal sent by the baseband processing unit to the wireless communication network; The antenna array is configured to receive the radio frequency calibration signal sent by the baseband processing unit through the coupling antenna in the wireless communication network, and transmit a coupling signal corresponding to the radio frequency calibration signal to the baseband processing unit; The baseband processing unit is further configured to calibrate the multiple baseband signals to be transmitted corresponding to the multiple transmission channels according to the difference between the radio frequency calibration signal and the coupling signal.

8. The antenna calibration system according to claim 7, wherein: The multiple transmission channels include multiple signal transmission channels and at least one calibration channel; wherein the multiple transmission ports correspond to the multiple signal transmission channels, and the coupling antenna corresponds to the at least one calibration channel.

9. The antenna calibration system according to claim 8, characterized in that: The baseband processing unit is used to send the radio frequency calibration signal through the calibration channel; The coupling antenna is used to couple the radio frequency calibration signal to the signal transmission channel, and transmit a coupling signal corresponding to the radio frequency calibration signal to the baseband processing unit through the signal transmission channel.

10. The antenna calibration system according to claim 8 or 9, characterized in that: The antenna calibration system further includes a digital phase shifter, and the coupled antenna is connected to the calibration port via the digital phase shifter.

11. The antenna calibration system according to claim 10, characterized in that: The number of the coupling antennas is equal to the number of the calibration channels.

12. The antenna calibration system according to claim 10, wherein: The antenna calibration system further includes a combiner, the number of the coupled antennas is greater than the number of the calibration channels, and the antenna calibration system includes one calibration channel.

13. An antenna calibration method, characterized in that: The method comprises: The baseband processing unit transmits a radio frequency calibration signal to the wireless communication network through the antenna array; the radio frequency calibration signal is transmitted by the baseband processing unit to the antenna array through a transmission channel in a radio remote unit; the radio remote unit provides multiple transmission channels; the multiple transmission channels correspond to multiple transmission ports of the antenna array; receiving a radio frequency calibration signal in the wireless communication network via a coupling antenna; transmitting the coupled signal corresponding to the radio frequency calibration signal back to the baseband processing unit through the transmission channel; A plurality of to-be-transmitted baseband signals in the baseband processing unit are calibrated according to a difference between the coupled signal and the radio frequency calibration signal.

14. The method according to claim 13, wherein: The transmission channel includes a plurality of signal transmission channels and at least one calibration channel, and the coupling antenna is connected to the at least one calibration channel.

15. The method according to claim 14, characterized in that When the radio frequency calibration signal is sent by the baseband processing unit to the antenna array through the multiple signal transmission channels, transmitting the coupled signal corresponding to the radio frequency calibration signal back to the baseband processing unit through the transmission channel includes: The coupled signal corresponding to the radio frequency calibration signal is transmitted to the baseband processing unit through the at least one calibration transmission channel.

16. The method according to claim 15, characterized in that The method further comprises: The phase of the coupled signal is adjusted by a digital phase shifter according to the phase information of the radio frequency calibration signal; wherein the digital phase shifter is located between the coupled antenna and the at least one calibration channel.

17. The method according to any one of claims 13 to 16, characterized in that The calibrating the multiple baseband signals to be transmitted in the baseband processing unit includes: The phases and amplitudes of a plurality of baseband signals to be transmitted in the baseband processing unit are calibrated.

18. An antenna calibration method, characterized in that: The method comprises: The radio frequency calibration signal sent by the baseband processing unit is transmitted to the wireless communication network through the coupled antenna; the radio frequency calibration signal is transmitted by the baseband processing unit to the coupled antenna through a transmission channel in the radio remote unit; the radio remote unit provides multiple transmission channels; the multiple transmission channels correspond to multiple transmission ports of the antenna array; receiving a radio frequency calibration signal in the wireless communication network via the antenna array; transmitting the coupled signal corresponding to the radio frequency calibration signal back to the baseband processing unit through the transmission channel; A plurality of to-be-transmitted baseband signals in the baseband processing unit are calibrated according to a difference between the coupled signal and the radio frequency calibration signal.

19. The method according to claim 18, characterized in that The transmission channel includes a plurality of signal transmission channels and at least one calibration channel, and the coupling antenna is connected to the at least one calibration channel.

20. The method according to claim 19, characterized in that When the radio frequency calibration signal is sent by the baseband processing unit to the coupling antenna through the at least one calibration channel, transmitting the coupling signal corresponding to the radio frequency calibration signal back to the baseband processing unit through the transmission channel includes: The coupled signal corresponding to the radio frequency calibration signal is transmitted to the baseband processing unit through the multiple transmission channels.

21. The method according to claim 20, characterized in that The method further comprises: The phase of the coupled signal is adjusted by a digital phase shifter according to the phase information of the radio frequency calibration signal; wherein the digital phase shifter is located between the coupled antenna and the at least one calibration channel.

22. The method according to any one of claims 18 to 21, characterized in that The calibrating the multiple baseband signals to be transmitted in the baseband processing unit includes: The phases and amplitudes of a plurality of baseband signals to be transmitted in the baseband processing unit are calibrated.

23. A computer-readable storage medium storing one or more computer-executable instructions, characterized in that: When the computer-executable instructions are executed by a processor, the processor performs the method according to any one of claims 13 to 22.

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