Antenna calibration method and device and storage medium

Abstract

The invention provides an antenna calibration method and device and a storage medium, and relates to the technical field of communication. The method comprises the following steps: determining a first calibration sequence; sending the first calibration sequence through one antenna in the M antennas, and receiving data through other (M-1) antennas except the one antenna in the M antennas, so as to obtain a plurality of second calibration sequences; and performing calibration processing on the M antennas according to the first calibration sequence and the plurality of second calibration sequences. In the whole calibration process, only one antenna needs to be used for sending the calibration sequence, the situation that a plurality of antennas are used for sending the calibration sequence, and consequently received signals are saturated and distorted is avoided, and the robustness of the calibration scheme is improved.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to an antenna calibration method, device and storage medium. Background Art

[0002] In a massive multi-input multi-output (MIMO) system, a large number of antennas are used to form spatial narrow beamforming, making full use of the spatial dimension to obtain multi-user multiplexing gain, which can effectively improve the cell spectrum efficiency and capacity. During the use of the antenna, the phase and amplitude of the antenna path may change due to changes in environmental factors. Therefore, the antenna needs to be calibrated to accurately perform beamforming.

[0003] In the related art, self-calibration is usually performed by using the short-range radiation of the internal antenna of the remote radio frequency unit (RRU), that is, the calibration sequence is sent through the internal antenna of the RRU, and then the calibration sequence is received through the internal antenna of the RRU, and the antenna is calibrated by the calibration sequences before and after receiving. This self-calibration scheme involves the situation where multiple antennas send the calibration sequence and one antenna receives it. In this case, saturation distortion of the received signal is likely to occur, resulting in low robustness of the final calibration. Summary of the invention

[0004] The present application provides an antenna calibration method, device and storage medium, which solve the technical problem of low robustness of existing antenna calibration solutions.

[0005] In a first aspect, an embodiment of the present application provides an antenna calibration method, which is applied to a network device, wherein the network device is provided with M antennas, where M is a positive integer greater than 1, and the method includes:

[0006] determining a first calibration sequence;

[0007] Sending the first calibration sequence through one antenna among the M antennas, and receiving data through other M-1 antennas among the M antennas except the one antenna, so as to obtain a plurality of second calibration sequences;

[0008] The M antennas are calibrated according to the first calibration sequence and the multiple second calibration sequences.

[0009] In one implementation, sending the first calibration sequence through one antenna among the M antennas, and receiving data through other M-1 antennas among the M antennas except the one antenna to obtain multiple second calibration sequences includes:

[0010] Sending the first calibration sequence through an i-th antenna among the M antennas, and receiving data through other M-1 antennas among the M antennas except the i-th antenna, so as to obtain M-1 second calibration sequences;

[0011] The i is sequentially 1, 2, ..., M until M*(M-1) second calibration sequences are obtained, and the multiple second calibration sequences are the M*(M-1) second calibration sequences.

[0012] In one embodiment, determining the first calibration sequence includes:

[0013] Determine frequency domain mapping location and initial calibration sequence;

[0014] Mapping the initial calibration sequence to the frequency domain mapping position to obtain a third calibration sequence;

[0015] Perform time-frequency transformation on the third calibration sequence to obtain the first calibration sequence.

[0016] In one implementation, mapping the initial calibration sequence to the frequency domain mapping position to obtain a third calibration sequence includes:

[0017] The third calibration sequence is obtained by the following formula:

[0018]

[0019] in, For the third calibration sequence, is an integer greater than or equal to 1 and less than or equal to N*12; n1 is the frequency domain mapping position, and n1 is an integer greater than or equal to 1 and less than or equal to 12; S TX (k) is the initial calibration sequence, k is an integer greater than or equal to 1 and less than or equal to N, and N is the number of resource blocks in the system bandwidth.

[0020] In one implementation, the performing calibration processing on the M antennas according to the first calibration sequence and the plurality of second calibration sequences includes:

[0021] Performing time-frequency transformation processing on the multiple second calibration sequences respectively to obtain multiple fourth calibration sequences;

[0022] Demapping the plurality of fourth calibration sequences respectively according to the frequency domain mapping positions to obtain a plurality of fifth calibration sequences;

[0023] The M antennas are calibrated according to the initial calibration sequence and the multiple fifth calibration sequences corresponding to the first calibration sequence.

[0024] In one implementation, demapping the plurality of fourth calibration sequences respectively according to the frequency domain mapping positions to obtain a plurality of fifth calibration sequences includes:

[0025] For any fourth calibration sequence, the corresponding fifth calibration sequence is obtained by the following formula:

[0026]

[0027] in, is the fifth calibration sequence, sel is the number of the antenna sending the first calibration sequence; n1 is the frequency domain mapping position, and n1 is an integer greater than or equal to 1 and less than or equal to 12; is the fourth calibration sequence, is an integer greater than or equal to 1 and less than or equal to N*12, N is the number of resource blocks in the system bandwidth, and m is the number of the antenna for data reception.

[0028] In one implementation, the calibrating the M antennas according to the initial calibration sequence and the plurality of fifth calibration sequences corresponding to the first calibration sequence includes:

[0029] Determining a plurality of channel estimation matrices according to the initial calibration sequence and the plurality of fifth calibration sequences;

[0030] determining a plurality of calibration factors based on the plurality of channel estimation matrices;

[0031] The M antennas are calibrated according to the multiple calibration factors.

[0032] In one implementation, determining a plurality of calibration factors according to the plurality of channel estimation matrices includes:

[0033] Determining a plurality of reference antennas among the M antennas;

[0034] Determining a plurality of target channel estimation matrices among the plurality of channel estimation matrices according to the plurality of reference antennas;

[0035] The plurality of calibration factors are determined according to the plurality of target channel estimation matrices.

[0036] In a second aspect, an embodiment of the present application provides an antenna calibration device, which is applied to a network device, wherein the network device is provided with M antennas, where M is a positive integer greater than 1, and the device includes:

[0037] A memory for storing a computer program; a transceiver for transmitting and receiving data under the control of a processor; and the processor for reading the computer program in the memory and performing the following operations:

[0038] determining a first calibration sequence;

[0039] Sending the first calibration sequence through one antenna among the M antennas, and receiving data through other M-1 antennas among the M antennas except the one antenna, so as to obtain a plurality of second calibration sequences;

[0040] The M antennas are calibrated according to the first calibration sequence and the multiple second calibration sequences.

[0041] In one implementation, the processor is specifically configured to perform the following operations:

[0042] Sending the first calibration sequence through an i-th antenna among the M antennas, and receiving data through other M-1 antennas among the M antennas except the i-th antenna, so as to obtain M-1 second calibration sequences;

[0043] The i is sequentially 1, 2, ..., M until M*(M-1) second calibration sequences are obtained, and the multiple second calibration sequences are the M*(M-1) second calibration sequences.

[0044] In one implementation, the processor is specifically configured to perform the following operations:

[0045] Determine frequency domain mapping location and initial calibration sequence;

[0046] Mapping the initial calibration sequence to the frequency domain mapping position to obtain a third calibration sequence;

[0047] Perform time-frequency transformation on the third calibration sequence to obtain the first calibration sequence.

[0048] In one implementation, the processor obtains the third calibration sequence by the following formula:

[0049]

[0050] in, For the third calibration sequence, is an integer greater than or equal to 1 and less than or equal to N*12; n1 is the frequency domain mapping position, and n1 is an integer greater than or equal to 1 and less than or equal to 12; S TX (k) is the initial calibration sequence, k is an integer greater than or equal to 1 and less than or equal to N, and N is the number of resource blocks in the system bandwidth.

[0051] In one implementation, the processor is specifically configured to perform the following operations:

[0052] Performing time-frequency transformation processing on the multiple second calibration sequences respectively to obtain multiple fourth calibration sequences;

[0053] Demapping the plurality of fourth calibration sequences respectively according to the frequency domain mapping positions to obtain a plurality of fifth calibration sequences;

[0054] The M antennas are calibrated according to the initial calibration sequence and the multiple fifth calibration sequences corresponding to the first calibration sequence.

[0055] In one implementation, for any fourth calibration sequence, the processor obtains the corresponding fifth calibration sequence by the following formula:

[0056]

[0057] in, is the fifth calibration sequence, sel is the number of the antenna sending the first calibration sequence; n1 is the frequency domain mapping position, and n1 is an integer greater than or equal to 1 and less than or equal to 12; is the fourth calibration sequence, is an integer greater than or equal to 1 and less than or equal to N*12, N is the number of resource blocks in the system bandwidth, and m is the number of the antenna for data reception.

[0058] In one implementation, the processor is specifically configured to perform the following operations:

[0059] Determining a plurality of channel estimation matrices according to the initial calibration sequence and the plurality of fifth calibration sequences;

[0060] determining a plurality of calibration factors based on the plurality of channel estimation matrices;

[0061] The M antennas are calibrated according to the multiple calibration factors.

[0062] In one implementation, the processor is specifically configured to perform the following operations:

[0063] Determining a plurality of reference antennas among the M antennas;

[0064] Determining a plurality of target channel estimation matrices among the plurality of channel estimation matrices according to the plurality of reference antennas;

[0065] The plurality of calibration factors are determined according to the plurality of target channel estimation matrices.

[0066] In a third aspect, an embodiment of the present application provides an antenna calibration device, which is applied to a network device, wherein the network device is provided with M antennas, where M is a positive integer greater than 1, and the device includes:

[0067] a determining unit, configured to determine a first calibration sequence;

[0068] a transceiver unit, configured to send the first calibration sequence through one antenna among the M antennas, and receive data through other M-1 antennas among the M antennas except the one antenna, so as to obtain a plurality of second calibration sequences;

[0069] A calibration processing unit is used to perform calibration processing on the M antennas according to the first calibration sequence and the multiple second calibration sequences.

[0070] In one implementation, the transceiver unit is specifically configured to:

[0071] Sending the first calibration sequence through an i-th antenna among the M antennas, and receiving data through other M-1 antennas among the M antennas except the i-th antenna, so as to obtain M-1 second calibration sequences;

[0072] The i is sequentially 1, 2, ..., M until M*(M-1) second calibration sequences are obtained, and the multiple second calibration sequences are the M*(M-1) second calibration sequences.

[0073] In one implementation, the determining unit is specifically configured to:

[0074] Determine frequency domain mapping location and initial calibration sequence;

[0075] Mapping the initial calibration sequence to the frequency domain mapping position to obtain a third calibration sequence;

[0076] Perform time-frequency transformation on the third calibration sequence to obtain the first calibration sequence.

[0077] In one implementation, the determining unit obtains the third calibration sequence by the following formula:

[0078]

[0079] in, For the third calibration sequence, is an integer greater than or equal to 1 and less than or equal to N*12; n1 is the frequency domain mapping position, and n1 is an integer greater than or equal to 1 and less than or equal to 12; S TX (k) is the initial calibration sequence, k is an integer greater than or equal to 1 and less than or equal to N, and N is the number of resource blocks in the system bandwidth.

[0080] In one implementation, the calibration processing unit is specifically configured to:

[0081] Performing time-frequency transformation processing on the multiple second calibration sequences respectively to obtain multiple fourth calibration sequences;

[0082] Demapping the plurality of fourth calibration sequences respectively according to the frequency domain mapping positions to obtain a plurality of fifth calibration sequences;

[0083] The M antennas are calibrated according to the initial calibration sequence and the multiple fifth calibration sequences corresponding to the first calibration sequence.

[0084] In one implementation, for any fourth calibration sequence, the calibration processing unit obtains the corresponding fifth calibration sequence by the following formula:

[0085]

[0086] in, is the fifth calibration sequence, sel is the number of the antenna sending the first calibration sequence; n1 is the frequency domain mapping position, and n1 is an integer greater than or equal to 1 and less than or equal to 12; is the fourth calibration sequence, is an integer greater than or equal to 1 and less than or equal to N*12, N is the number of resource blocks in the system bandwidth, and m is the number of the antenna for data reception.

[0087] In one implementation, the calibration processing unit is specifically configured to:

[0088] Determining a plurality of channel estimation matrices according to the initial calibration sequence and the plurality of fifth calibration sequences;

[0089] determining a plurality of calibration factors based on the plurality of channel estimation matrices;

[0090] The M antennas are calibrated according to the multiple calibration factors.

[0091] In one implementation, the calibration processing unit is specifically configured to:

[0092] Determining a plurality of reference antennas among the M antennas;

[0093] Determining a plurality of target channel estimation matrices among the plurality of channel estimation matrices according to the plurality of reference antennas;

[0094] The plurality of calibration factors are determined according to the plurality of target channel estimation matrices.

[0095] In a fourth aspect, an embodiment of the present application provides a processor-readable storage medium, wherein the processor-readable storage medium stores a computer program, and the computer program is used to enable the processor to execute the method described in the first aspect.

[0096] The present application provides an antenna calibration method, device and storage medium, in which a first calibration sequence is determined; the first calibration sequence is sent through one of the M antennas, and data is received through the other M-1 antennas except one of the M antennas to obtain multiple second calibration sequences; the M antennas are calibrated according to the first calibration sequence and the multiple second calibration sequences. The entire calibration process only requires one antenna to send the calibration sequence, avoiding the situation where the received signal is saturated and distorted when multiple antennas are used to send the calibration sequence, thereby improving the robustness of the calibration scheme.

[0097] It should be understood that the contents described in the above summary of the invention are not intended to limit the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0098] In order to more clearly illustrate the technical solutions in the present application or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0099] Figure 1 A schematic diagram of an architecture of a communication system provided in an embodiment of the present application;

[0100] Figure 2 A schematic diagram of modeling reciprocity errors of uplink and downlink channels in the related art;

[0101] Figure 3 A schematic diagram of mutual transmission of calibration sequences between antennas within a PICO RRU in the related art;

[0102] Figure 4 It is a schematic diagram of mapping of multiple-transmit and single-receive timing calibration sequences in the related art;

[0103] Figure 5 A flowchart of an antenna calibration method provided in an embodiment of the present application;

[0104] Figure 6 A schematic diagram of the calibration sequence between antennas inside the RRU provided in an embodiment of the present application;

[0105] Figure 7 A schematic diagram of a flow chart of another antenna calibration method provided in an embodiment of the present application;

[0106] Figure 8 A schematic diagram of mapping the initial calibration sequence provided in an embodiment of the present application;

[0107] Fig. 9 A schematic diagram of two antennas transmitting to each other provided in an embodiment of the present application;

[0108] Fig.10 A schematic diagram of the structure of an antenna calibration device provided in an embodiment of the present application;

[0109] Fig.11 A schematic diagram of the structure of another antenna calibration device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0110] In the embodiments of the present invention, the term "and / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent three situations: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0111] In the embodiments of the present application, the term "plurality" refers to two or more than two, and other quantifiers are similar.

[0112] The descriptions of "first", "second", etc. that appear in the embodiments of the present application are only used for illustration and distinction of the described objects, and there is no order, nor does it indicate a special limitation on the number of data in the embodiments of the present application, and cannot constitute any limitation on the embodiments of the present application. For example, the first calibration sequence is a time-frequency sequence before transmission, and the third calibration sequence is a frequency domain sequence before transmission. The descriptions of "first", "third", etc. are only used to distinguish between different forms of calibration sequences, rather than to indicate the difference in size, priority, or importance of the two elements.

[0113] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0114] Embodiments of the present application provide an antenna calibration method and apparatus to improve the robustness of a calibration scheme.

[0115] Among them, the method and the device are based on the same application concept. Since the method and the device solve the problem in a similar principle, the implementation of the device and the method can refer to each other, and the repeated parts will not be repeated.

[0116] The technical solution provided in the embodiment of the present application can be applicable to a variety of systems, especially 5G systems. For example, the applicable system can be a global system of mobile communication (GSM) system, a code division multiple access (CDMA) system, a wideband code division multiple access (WCDMA) general packet radio service (GPRS) system, a long term evolution (LTE) system, a LTE frequency division duplex (FDD) system, a LTE time division duplex (TDD) system, an advanced long term evolution (LTE-A) system, a universal mobile telecommunication system (UMTS), a world-wide interoperability for microwave access (WiMAX) system, a 5G new radio (NR) system, etc. These various systems include terminal equipment and network equipment. The system may also include a core network part, such as an evolved packet system (EPS), a 5G system (5GS), etc.

[0117] The network device involved in the embodiment of the present application may be a base station, which may include multiple cells providing services for the terminal. Depending on the specific application scenario, the base station may also be called an access point, or may be a device in the access network that communicates with the wireless terminal device through one or more sectors on the air interface, or other names. The network device may be used to interchange received air frames with Internet Protocol (IP) packets, and serve as a router between the wireless terminal device and the rest of the access network, wherein the rest of the access network may include an Internet Protocol (IP) communication network. The network device may also coordinate the attribute management of the air interface. For example, the network device involved in the embodiments of the present application may be a network device (base transceiver station, BTS) in the global system for mobile communications (global system for mobile communications, GSM) or code division multiple access (code division multiple access, CDMA), or a network device (NodeB) in wide-band code division multiple access (WCDMA), or an evolutionary network device (evolutional Node B, eNB or e-NodeB) in the long term evolution (long term evolution, LTE) system, a 5G base station (gNB) in the 5G network architecture (next generation system), or a home evolved node B (home evolved node B, HeNB), a relay node, a home base station (femto), a pico base station (pico), etc., which is not limited in the embodiments of the present application. In some network structures, the network device may include a centralized unit (CU) node and a distributed unit (DU) node, and the centralized unit and the distributed unit may also be arranged geographically separately.

[0118] Combine the following Figure 1 The communication scenario of this application is described. Figure 1 A schematic diagram of the architecture of a communication system provided in an embodiment of the present application.

[0119] like Figure 1 As shown, the architecture 100 includes a network device 101 and a terminal device 102. The network device 101 and the terminal device 102 may be configured with multiple antennas.

[0120] In the indoor application scenario of time division duplexing (TDD), for a single RRU, non-codebook shaping can be achieved in theory. In order to reduce costs, the indoor RRU does not have an internal calibration network, and antenna calibration cannot be achieved. The uplink / downlink channel characteristics are not aligned, and there may be large differences between channels, which will greatly reduce performance and even cause negative gain. In addition, the difference in characteristics between channels is also not conducive to codebook shaping, which will affect the performance of codebook shaping.

[0121] Figure 2 The modeling of reciprocity error in uplink and downlink channels is shown, as Figure 2 As shown, H AI,DL is the downlink air interface channel frequency response, H AI,UL is the uplink air interface channel frequency response, H bt is the frequency response of the network device transmission channel, H br is the frequency response of the receiving channel of the network device, H mt is the frequency response of the terminal device transmission channel, H mr It is the receiving channel frequency response of the terminal equipment.

[0122] Among them, the synthetic channel frequency response H sent by the network device to the terminal device is DL It can be expressed as:

[0123] H DL =H mr H AI,DL H bt

[0124] The composite channel frequency response H sent by the terminal device to the network device UL It can be expressed as:

[0125] H UL =H br H AI,UL H mt

[0126] To simplify, there are usually two assumptions:

[0127] 1) The uplink and downlink delays are very small, within the coherence time.

[0128] 2) Coupling between antennas is not considered, so the response of the radio frequency (RF) circuit (H mr ,H br ,H mt ,H bt ) can be considered as diagonal matrices. That is, H br =diag(h br,1 ,h br,2 ,…,hbr,M ), where M is the number of antennas set on the network device, h br,1 Indicates the receiving channel frequency response of the first antenna on the network device, h br,2 Indicates the receiving channel frequency response of the second antenna on the network device, h br,M Indicates the receiving channel frequency response of the Mth antenna on the network device.

[0129] The reciprocity error E on the terminal equipment side m Defined as:

[0130]

[0131] Where N is the number of antennas set on the terminal device, e m,1 represents the reciprocity error of the first antenna on the terminal device side, e m,2 Represents the reciprocity error of the second antenna on the terminal device side, e m,N Indicates the reciprocity error of the Nth antenna on the terminal device side.

[0132] The reciprocity error E on the network device side b Defined as:

[0133]

[0134] Where M is the number of antennas installed on the network device, e b,1 Represents the reciprocity error of the first antenna on the network device side, e b,2 Represents the reciprocity error of the second antenna on the network device side, e b,M Indicates the reciprocity error of the Mth antenna on the network device side.

[0135] Then the relationship between the uplink channel and the downlink channel can be expressed as:

[0136]

[0137] In the related art, the RRU internal antenna is usually used for close-range radiation for self-calibration, without the need for a calibration loopback network and feedback from terminal devices.

[0138] Taking a 4-antenna pico RRU as an example, the calibration sequence between internal antennas is shown in the diagram below: Figure 3 As shown, the calibration process is as follows:

[0139] First round of calibration: select antenna 1 as the reference antenna, and map the standard sequence to antenna 2, antenna 3, and antenna 4 respectively. Figure 4As shown, the calibration sequences of different antennas are mapped to different resource element (RE) positions respectively; then the mapped standard sequences are sent to antenna 1 respectively. After antenna 1 receives the standard sequence, channel estimation is performed according to the standard sequence before transmission and the received standard sequence to obtain the channel estimation matrix Wherein, DL indicates that other antennas send calibration sequences to the reference antenna, m is the antenna number, N is the number of resource blocks (RBs) included in the system bandwidth, and is also the length of the calibration sequence. Antenna 1 maps the calibration sequence and sends the mapped calibration sequence to antenna 2, antenna 3, and antenna 4. After receiving the calibration sequence, antenna 2, antenna 3, and antenna 4 perform channel estimation based on the standard sequence before transmission and the received standard sequence, respectively, to obtain the channel estimation matrix UL indicates that the reference antenna sends a calibration sequence to other antennas. and Calculate the calibration factor for the first round of calibration

[0140] Second round of calibration: select antenna 4 as the reference antenna, and map the standard sequence to antenna 1, antenna 2, and antenna 3 respectively. The calibration sequences of different antennas are mapped to different RE positions respectively. Then send the mapped standard sequence to antenna 4 respectively. After antenna 4 receives the standard sequence, it performs channel estimation based on the standard sequence before transmission and the received standard sequence to obtain the channel estimation matrix Among them, DL means that other antennas send calibration sequences to the reference antenna, m is the antenna number, N is the number of RBs included in the system bandwidth, and is also the length of the calibration sequence. Then antenna 4 maps the calibration sequence and sends the mapped calibration sequence to antenna 1, antenna 2, and antenna 3. After receiving the calibration sequence, antenna 1, antenna 2, and antenna 3 perform channel estimation based on the standard sequence before transmission and the received standard sequence, respectively, to obtain the channel estimation matrix UL indicates that the reference antenna sends a calibration sequence to other antennas. and Calculate the calibration factor for the second round of calibration

[0141] Combine the calibration factors of the two rounds to obtain the calibration factors of the four antennas; then interpolate the calibration factors of the four antennas to obtain the RE-level calibration factors of the four antennas. Compensate the frequency domain transmission data of the four antennas according to the RE-level calibration factors of the four antennas to obtain the calibration-compensated transmission data and complete the calibration.

[0142] The above calibration scheme has the following problems:

[0143] (1) The RRU's transmit / receive function needs to be switched twice, i.e., from the 4-antenna transmit state to the 3-antenna transmit and 1-receive state, and then from the 3-antenna transmit and 1-receive state to the 1-antenna transmit and 3-receive state, which places high demands on hardware processing.

[0144] (2) Since 1 transmit and 3 receive and 3 transmit and 1 receive require different calibration sequences and different mapping methods, the solution is relatively complex to handle.

[0145] (3) Since this scheme uses close-range radiation, in the case of 3 transmitters and 1 receiver, it is easy for the received signal to be saturated and distorted, making the robustness of this scheme low.

[0146] Based on the problems in the prior art, the present application proposes the following technical concept: each time the antennas are closely connected, only one antenna is used to send the calibration sequence, and the other antennas receive the calibration sequence. This reduces the state switching of the RRU receiving / transmitting function; at the same time, since only one antenna is used to send the calibration sequence each time, each antenna can use the same calibration sequence, making the processing process of this solution relatively simple; in addition, this solution avoids multiple transmissions and a single reception, and thus does not cause the situation of saturation and distortion of the received signal, making this solution more robust.

[0147] The frequency offset estimation method provided by the present application is introduced below in conjunction with specific embodiments.

[0148] Figure 5 This is a flow chart of an antenna calibration method provided in an embodiment of the present application. Figure 5 As shown, the method includes:

[0149] S501: Determine a first calibration sequence.

[0150] The execution subject of the embodiment of the present application may be a network device, or an antenna calibration device arranged in the network device. The antenna calibration device may be implemented by software, or by a combination of software and hardware.

[0151] The network device is provided with M antennas, where M is a positive integer greater than 1.

[0152] The first calibration sequence may be a time-frequency sequence.

[0153] S502: Send a first calibration sequence through one antenna among the M antennas, and receive data through other M-1 antennas except one antenna among the M antennas to obtain multiple second calibration sequences.

[0154] The second calibration sequence may be a time-frequency sequence.

[0155] The first calibration sequence and the second calibration sequence may be the same or different.

[0156] When the channel is in an ideal state, the first calibration sequence will not change during the transmission process, and at this time, the first calibration sequence is the same as the second calibration sequence; when the channel is in a non-ideal state, the first calibration sequence will change during the transmission process, and at this time, the first calibration sequence is different from the second calibration sequence.

[0157] Sending the first calibration sequence through one of the M antennas may mean sending the first calibration sequence through one of the M antennas in sequence.

[0158] Sending the first calibration sequence through one of the M antennas in sequence may mean sending the first calibration sequence once through each of the M antennas, sending the first calibration sequence M times in total, and the sending order of the M antennas may be random.

[0159] In one possible implementation, the calibration sequence may be sent and received in the following manner:

[0160] A first calibration sequence is sent through the i-th antenna among the M antennas, and data is received through other M-1 antennas among the M antennas except the i-th antenna to obtain M-1 second calibration sequences; wherein i is 1, 2, ..., M in sequence until M*(M-1) second calibration sequences are obtained, and the multiple second calibration sequences are M*(M-1) second calibration sequences.

[0161] For example, Figure 6 As shown, assuming that there are four antennas, namely antenna 1, antenna 2, antenna 3 and antenna 4, the first calibration sequence can be sent through antenna 1 first, and data is received through antenna 2, antenna 3 and antenna 4 respectively, to obtain three second calibration sequences; then the first calibration sequence is sent through antenna 2, and data is received through antenna 1, antenna 3 and antenna 4 respectively, to obtain three second calibration sequences; then the first calibration sequence is sent through antenna 3, and data is received through antenna 1, antenna 2 and antenna 4 respectively, to obtain three second calibration sequences; finally, the first calibration sequence is sent through antenna 4, and data is received through antenna 1, antenna 2 and antenna 3 respectively, to obtain three second calibration sequences, and a total of 12 calibration sequences are obtained.

[0162] Reception and transmission of the calibration sequence can be performed in the upper / lower switching interval.

[0163] S503: Perform calibration processing on M antennas according to the first calibration sequence and multiple second calibration sequences.

[0164] In a possible implementation, the M antennas may be calibrated in the following manner:

[0165] A plurality of channel estimation matrices may be determined according to the first calibration sequence and the plurality of second calibration sequences, a plurality of calibration factors may be determined according to the plurality of channel estimation matrices, and calibration processing may be performed on the M antennas according to the plurality of calibration factors.

[0166] Each antenna corresponds to a calibration factor. For any antenna, calibrating the antenna according to the calibration factor corresponding to the antenna may mean compensating the frequency domain transmission data of the antenna by the calibration factor, thereby completing the calibration of the antenna.

[0167] exist Figure 5 In the illustrated embodiment, a first calibration sequence is determined; the first calibration sequence is sent through one of the M antennas, and data is received through the other M-1 antennas except one of the M antennas to obtain multiple second calibration sequences; the M antennas are calibrated according to the first calibration sequence and the multiple second calibration sequences. In each transmission process of the first calibration sequence, only one antenna is used to send the first calibration sequence, which reduces the state switching of the RRU receiving / transmitting function; at the same time, since only one antenna is used to send the first calibration sequence each time, each antenna can use the same first calibration sequence, making the processing process of this solution relatively simple; in addition, this solution avoids multiple transmissions and single reception, and thus does not cause saturation and distortion of the received signal, making the robustness of this solution better.

[0168] exist Figure 5 Based on the embodiment shown below, combined with Figure 7 The antenna calibration method of the present application is described in detail.

[0169] Figure 7 A schematic diagram of a flow chart of another antenna calibration method provided in an embodiment of the present application. Figure 7 As shown, the method includes:

[0170] S701: Determine a frequency domain mapping position and an initial calibration sequence.

[0171] The initial calibration sequence may be a frequency domain sequence.

[0172] The initial calibration sequence may be instructed by the network device.

[0173] The number of time domain symbols occupied by the initial calibration sequence may be specified by a communication protocol or indicated by a network device.

[0174] The length of the initial calibration sequence may be the same as the length of the system bandwidth.

[0175] Exemplarily, if the length of the system bandwidth is N RBs, the length of the initial calibration sequence may be N, that is, the initial calibration sequence may be composed of N unit sequences, and the frequency domain interval between adjacent unit sequences is 1 RB (1 RB includes 12 REs).

[0176] The frequency domain mapping position may be indicated by the network device.

[0177] The frequency domain mapping position may refer to a mapping position at the RE level.

[0178] Exemplarily, the frequency domain mapping position is RE6, which may mean mapping each unit sequence of the initial calibration sequence to the 6th RE of the corresponding RB.

[0179] S702: Map the initial calibration sequence to a frequency domain mapping position to obtain a third calibration sequence.

[0180] It may refer to mapping each unit sequence of the initial calibration sequence to a frequency domain mapping position of a corresponding RB.

[0181] For example, Figure 8 As shown, if the system bandwidth includes N RBs, the length of the initial calibration sequence is N, the frequency domain interval of each adjacent unit sequence is 1 RB, the frequency domain mapping position is RE6, and mapping the initial calibration sequence to the frequency domain mapping position may mean mapping the 1st unit sequence of the initial calibration sequence to the 6th RE of the 1st RB, mapping the 2nd unit sequence of the initial calibration sequence to the 6th RE of the 2nd RB, and so on, mapping the Nth unit sequence of the initial calibration sequence to the 6th RE of the Nth RB.

[0182] The third calibration sequence may be a frequency domain sequence.

[0183] In a possible implementation, the third calibration sequence may be obtained by the following formula:

[0184]

[0185] in, For the third calibration sequence, is an integer greater than or equal to 1 and less than or equal to N*12; n1 is the frequency domain mapping position, n2 is an integer greater than or equal to 1 and less than or equal to 12; S TX (k) is an initial calibration sequence, k is an integer greater than or equal to 1 and less than or equal to N, and N is the number of RBs in the system bandwidth.

[0186] S703: Perform time-frequency transformation on the third calibration sequence to obtain a first calibration sequence.

[0187] The time-frequency conversion process not only includes simple time-frequency conversion, but also includes processing such as zero padding and / or adding a cyclic prefix (CP).

[0188] The time-frequency transformation may refer to transforming the frequency domain into the time domain, or may refer to transforming the time domain into the frequency domain. In this step, the time-frequency transformation refers to transforming the frequency domain into the time domain.

[0189] According to actual conditions, the third calibration sequence may be processed in sequence by performing zero padding, frequency domain to time domain transformation, and CP addition to obtain the first calibration sequence.

[0190] S704: Send a first calibration sequence through one antenna among the M antennas, and receive data through other M-1 antennas except one antenna among the M antennas to obtain multiple second calibration sequences.

[0191] It should be noted that the execution process of S704 can refer to the execution process of S502, which will not be repeated here.

[0192] S705 . Perform time-frequency transformation processing on the multiple second calibration sequences respectively to obtain multiple fourth calibration sequences.

[0193] The time-frequency conversion process not only includes simple time-frequency conversion, but also includes processing such as CP removal and virtual subcarrier removal.

[0194] In this step, time-frequency transformation refers to transforming the time domain into the frequency domain.

[0195] According to actual conditions, operations such as CP removal, time domain to frequency domain transformation, and virtual subcarrier removal may be performed on each second calibration sequence in sequence to obtain a corresponding fourth calibration sequence.

[0196] S706. Demap the multiple fourth calibration sequences respectively according to the frequency domain mapping positions to obtain multiple fifth calibration sequences.

[0197] In a possible implementation, for any fourth calibration sequence, the corresponding fifth calibration sequence may be obtained by the following formula:

[0198]

[0199] in, is the fifth calibration sequence, sel is the number of the antenna that sends the first calibration sequence; n1 is the frequency domain mapping position, and n1 is an integer greater than or equal to 1 and less than or equal to 12; For the fourth calibration sequence, is an integer greater than or equal to 1 and less than or equal to N*12, N is the number of RBs in the system bandwidth, m is the number of antennas for data reception, and m≠sel.

[0200] S707: Perform calibration processing on the M antennas according to the initial calibration sequence and multiple fifth calibration sequences.

[0201] In a possible implementation, the M antennas may be calibrated in the following manner:

[0202] According to the initial calibration sequence and the multiple fifth calibration sequences, multiple channel estimation matrices are determined; according to the multiple channel estimation matrices, multiple calibration factors are determined; and according to the multiple calibration factors, calibration processing is performed on the M antennas.

[0203] The multiple channel estimation matrices may be determined using a minimum mean squared error (MMSE) criterion, or may be determined using other methods.

[0204] The number of the fifth calibration sequences may be the same as the number of channel estimation matrices. The number of channel estimation matrices may be M*(M-1).

[0205] If there are four antennas, namely antenna 1, antenna 2, antenna 3 and antenna 4. Antenna 1 is used to send the first calibration sequence, and antenna 2, antenna 3 and antenna 4 receive data respectively, and three second calibration sequences are obtained; according to the first calibration sequence and the three second calibration sequences, the channel estimation matrix can be obtained The first calibration sequence is sent through antenna 2, and data is received through antenna 1, antenna 3 and antenna 4 respectively to obtain three second calibration sequences; according to the first calibration sequence and the three second calibration sequences, the channel estimation matrix can be obtained The first calibration sequence is sent through antenna 3, and data is received through antenna 1, antenna 2 and antenna 4 respectively to obtain three second calibration sequences; according to the first calibration sequence and the three second calibration sequences, the channel estimation matrix can be obtained: Finally, the first calibration sequence is sent through antenna 4, and data is received through antenna 1, antenna 2 and antenna 3 respectively to obtain three second calibration sequences; according to the first calibration sequence and the three second calibration sequences, the channel estimation matrix can be obtained:

[0206] The number of calibration factors is the same as the number of antennas, which is M.

[0207] In one possible implementation, multiple calibration factors may be determined in the following manner:

[0208] A plurality of reference antennas are determined among the M antennas; a plurality of target channel estimation matrices are determined among the plurality of channel estimation matrices according to the plurality of reference antennas; and a plurality of calibration factors are determined according to the plurality of target channel estimation matrices.

[0209] In a possible implementation, multiple target channel estimation matrices may be determined in the following manner:

[0210] Among multiple channel estimation matrices, a channel estimation matrix obtained by sending a first calibration sequence with a reference antenna and receiving data with other antennas, and a channel estimation matrix obtained by sending a first calibration sequence with other antennas and receiving data with the reference antenna are determined as multiple target channel estimation matrices.

[0211] The calculation of the calibration factor can be performed in two rounds. A reference antenna is selected in each round, and the reference antennas of the two rounds are different.

[0212] Each round of calibration can obtain M-1 initial calibration factors.

[0213] After two rounds of calibration, 2*(M-1) initial calibration factors can be obtained. By merging and subtracting the 2*(M-1) initial calibration factors, M calibration factors can be finally obtained.

[0214] In each round of calibration, other antennas send calibration sequences to the reference antenna in the downlink direction (DL), and the reference antenna sends calibration sequences to other antennas in the uplink direction (UL).

[0215] Hereinafter, taking a total of four antennas, namely antenna 1, antenna 2, antenna 3 and antenna 4 as an example, how to determine multiple calibration factors according to multiple channel estimation matrices is described in detail.

[0216] In the following steps, m is the number of antennas, N is the number of RBs in the system bandwidth, superscript (1) indicates the first round of calibration, and superscript (2) indicates the second round of calibration.

[0217] (1) Select reference antenna

[0218] In the first round of calibration, antenna 1 is selected as the reference antenna, and in the second round of calibration, antenna 4 is selected as the reference antenna.

[0219] (2) Determine the target channel estimation matrix

[0220] (2-1) In the first round of calibration, the downlink channel estimation matrix from antenna 2, antenna 3 and antenna 4 to antenna 1, and the uplink channel estimation matrix from antenna 1 to antenna 2, antenna 3 and antenna 4 are determined as target channel estimation matrices, which are respectively denoted as:

[0221]

[0222] (2-2) In the second round of calibration, the downlink channel estimation matrices from antenna 1, antenna 2 and antenna 3 to antenna 4, and the uplink channel estimation matrix from antenna 4 to antenna 1, antenna 2 and antenna 3 are determined as target channel estimation matrices, which are respectively denoted as:

[0223]

[0224] (3) Calculation of calibration factors

[0225] (3-1) Calculate the first round of calibration factors:

[0226]

[0227] (3-2) Yes To perform normalization, other factors other than the reference antenna are selected as the benchmark, such as (or ), normalizing the other calibration factors to obtain:

[0228]

[0229] (3-3) Calculate the second round of calibration factors:

[0230]

[0231] (3-4) Yes To perform normalization, other factors other than the reference antenna are selected as the benchmark, such as (or ), normalizing the other calibration factors to obtain:

[0232]

[0233] (4) Calibration factor merging and interpolation

[0234] (4-1) Calibration factor merging: Merging the two rounds of calibration factors, the calibration factors of the four antennas are obtained as follows:

[0235]

[0236] in,

[0237] (4-2) is normalized again to obtain:

[0238]

[0239] (4-3) Calibration factor interpolation can be performed by MMSE filtering, linear interpolation, or even repeated interpolation. Interpolate and obtain the RE-level calibration factors for the four antennas:

[0240]

[0241] Each antenna corresponds to a calibration factor. For any antenna, calibrating the antenna according to the calibration factor corresponding to the antenna may mean compensating the frequency domain transmission data of the antenna by the calibration factor, thereby completing the calibration of the antenna.

[0242] For example, if there are four antennas, namely antenna 1, antenna 2, antenna 3 and antenna 4, the calibration factor is Transmit data in frequency domain To compensate, the calibration factor is multiplied by the frequency domain transmission data to obtain the frequency domain transmission data after calibration compensation:

[0243]

[0244] in, is the frequency domain transmission data after calibration compensation, m is the antenna number, and N is the number of RBs in the system bandwidth.

[0245] To receive data in the frequency domain For calibration, we have:

[0246]

[0247] in, is the frequency domain received data after calibration compensation, m is the antenna number, and N is the number of RBs in the system bandwidth.

[0248] It should be noted that calibration compensation only needs to be performed in one direction, either in transmission or reception, and there is no need to perform calibration compensation at the same time.

[0249] exist Figure 7In the illustrated embodiment, the frequency domain mapping position and the initial calibration sequence are determined; the initial calibration sequence is mapped to the frequency domain mapping position to obtain a third calibration sequence; the third calibration sequence is subjected to time-frequency transformation to obtain a first calibration sequence; the first calibration sequence is sent through one of the M antennas, and data is received through the other M-1 antennas except one of the M antennas to obtain multiple second calibration sequences; the multiple second calibration sequences are subjected to time-frequency transformation to obtain multiple fourth calibration sequences; the multiple fourth calibration sequences are demapped according to the frequency domain mapping position to obtain multiple fifth calibration sequences; the M antennas are calibrated according to the initial calibration sequence and the multiple fifth calibration sequences. In each transmission process of the first calibration sequence, only one antenna is used to send the first calibration sequence, which reduces the state switching of the RRU receiving / transmitting function; at the same time, since only one antenna is used to send the first calibration sequence each time, each antenna can use the same first calibration sequence, so that the mapping and demapping process of this solution is relatively simple; in addition, this solution avoids multiple transmissions and single receptions, and thus does not cause the situation of saturation distortion of the received signal, so that the robustness of this solution is better.

[0250] On the basis of any of the above embodiments, when executing the above antenna calibration solution, the receiving channels may be pre-calibrated to align the frequency responses of the receiving channels.

[0251] Pre-calibration can be performed using factory calibration or offline calibration.

[0252] Taking the 5G system as an example, some variables and parameters are explained as follows:

[0253] Assuming that the number of RBs in the system bandwidth is N (the number of REs is N·12), the channel frequency response experienced during signal reception / transmission is as follows:

[0254] (1) Channel frequency response of the mth antenna in the sending direction: Wherein, M is the number of antennas.

[0255] (2) Channel frequency response of the receiving direction of the mth antenna: M has the same meaning as above.

[0256] (3) Frequency response of the spatial propagation channel from the mth antenna to the nth antenna: And m≠n, and assume that That is, the propagation characteristics of the spatial channel are reciprocal, where Represents the frequency response of the spatial propagation channel from the nth antenna to the mth antenna.

[0257] For example, Fig. 9As shown, if antenna 1 sends a signal to antenna 2, it will go through antenna 1's sending channel, spatial channel, antenna 2's receiving channel, and subcarrier The total frequency response on If antenna 2 transmits a signal to antenna 1, it will go through antenna 2's transmit channel, spatial channel, antenna 1's receive channel, and subcarrier The total frequency response on

[0258] Taking factory calibration as an example, assuming that the pre-calibration factor of the mth antenna is obtained through factory calibration:

[0259]

[0260] Where A is a constant, and the receiving channel frequency response of the mth antenna after pre-calibration is:

[0261]

[0262] That is, the receiving channel frequency response of the mth antenna after pre-calibration The receiving channel frequency response of the nth antenna after pre-calibration The same, that is, the frequency response of the receiving channel after pre-calibration satisfies the following formula:

[0263]

[0264] It can be seen from the above formula that after pre-calibration, it is considered that the frequency response characteristics of each receiving channel have been aligned.

[0265] If the receiving channel is pre-calibrated, in order to avoid pre-calibration failure, it is recommended to perform calibration compensation on the transmitting end during the formal calibration process.

[0266] Fig.10 The schematic diagram of the structure of an antenna calibration device provided in an embodiment of the present application. The device is applied to a network device, and the network device is provided with M antennas, where M is a positive integer greater than 1; Fig.10 As shown, the device comprises:

[0267] Memory 1010 , transceiver 1020 and processor 1030 .

[0268] A memory 1010, used for storing computer programs;

[0269] The transceiver 1020 is used to send and receive data under the control of the processor 1030;

[0270] The processor 1030 is configured to read the computer program stored in the memory 1010 and perform the following operations:

[0271] determining a first calibration sequence;

[0272] Sending a first calibration sequence through one antenna among the M antennas, and receiving data through other M-1 antennas except one antenna among the M antennas to obtain multiple second calibration sequences;

[0273] According to the first calibration sequence and the multiple second calibration sequences, the M antennas are calibrated.

[0274] In one implementation, the processor 1030 is specifically configured to perform the following operations:

[0275] Sending a first calibration sequence through an i-th antenna among the M antennas, and receiving data through other M-1 antennas among the M antennas except the i-th antenna, so as to obtain M-1 second calibration sequences;

[0276] Here, i is sequentially 1, 2, ..., M until M*(M-1) second calibration sequences are obtained, and the plurality of second calibration sequences are M*(M-1) second calibration sequences.

[0277] In one implementation, the processor 1030 is specifically configured to perform the following operations:

[0278] Determine frequency domain mapping location and initial calibration sequence;

[0279] Mapping the initial calibration sequence to a frequency domain mapping position to obtain a third calibration sequence;

[0280] Perform time-frequency transformation on the third calibration sequence to obtain a first calibration sequence.

[0281] In one implementation, the processor 1030 obtains the third calibration sequence by the following formula:

[0282]

[0283] in, For the third calibration sequence, is an integer greater than or equal to 1 and less than or equal to N*12; n1 is the frequency domain mapping position, n2 is an integer greater than or equal to 1 and less than or equal to 12; S TX (k) is an initial calibration sequence, k is an integer greater than or equal to 1 and less than or equal to N, and N is the number of resource blocks in the system bandwidth.

[0284] In one implementation, the processor 1030 is specifically configured to perform the following operations:

[0285] Performing time-frequency transformation processing on the plurality of second calibration sequences respectively to obtain a plurality of fourth calibration sequences;

[0286] Demapping the plurality of fourth calibration sequences respectively according to the frequency domain mapping positions to obtain a plurality of fifth calibration sequences;

[0287] The M antennas are calibrated according to an initial calibration sequence corresponding to the first calibration sequence and a plurality of fifth calibration sequences.

[0288] In one implementation, for any fourth calibration sequence, the processor 1030 obtains the corresponding fifth calibration sequence by using the following formula:

[0289]

[0290] in, is the fifth calibration sequence, sel is the number of the antenna that sends the first calibration sequence; n1 is the frequency domain mapping position, and n1 is an integer greater than or equal to 1 and less than or equal to 12; For the fourth calibration sequence, is an integer greater than or equal to 1 and less than or equal to N*12, N is the number of resource blocks in the system bandwidth, and m is the number of the antenna for data reception.

[0291] In one implementation, the processor 1030 is specifically configured to perform the following operations:

[0292] Determining a plurality of channel estimation matrices according to the initial calibration sequence and a plurality of fifth calibration sequences;

[0293] Determining a plurality of calibration factors based on a plurality of channel estimation matrices;

[0294] The M antennas are calibrated according to the multiple calibration factors.

[0295] In one implementation, the processor 1030 is specifically configured to perform the following operations:

[0296] Determining a plurality of reference antennas among the M antennas;

[0297] Determining a plurality of target channel estimation matrices among a plurality of channel estimation matrices according to a plurality of reference antennas;

[0298] A plurality of calibration factors are determined based on a plurality of target channel estimation matrices.

[0299] Among them, Fig.10In the embodiment, the bus architecture may include any number of interconnected buses and bridges, specifically one or more processors represented by processor 1030 and various circuits of memory represented by memory 1010 are linked together. The bus architecture may also link together various other circuits such as peripherals, voltage regulators, and power management circuits, which are well known in the art and are therefore not further described herein. The bus interface provides an interface. The transceiver 1020 may be a plurality of components, namely, a transmitter and a receiver, providing a unit for communicating with various other devices on a transmission medium, which transmission medium may include a wireless channel, a wired channel, an optical cable, and other transmission media. The processor 1030 is responsible for managing the bus architecture and general processing, and the memory 1010 may store data used by the processor 1030 when performing operations.

[0300] The processor 1030 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or a complex programmable logic device (CPLD). The processor may also adopt a multi-core architecture.

[0301] It should be noted here that the above-mentioned device provided in the present application can implement all the method steps in the above-mentioned method embodiment and can achieve the same technical effect. The parts and beneficial effects of this embodiment that are the same as the method embodiment will not be described in detail here.

[0302] Fig.11 A schematic diagram of the structure of another antenna calibration device provided in an embodiment of the present application. The device is applied to a network device, and the network device is provided with M antennas, where M is a positive integer greater than 1; Fig.11 As shown, the device comprises:

[0303] A determining unit 1110, configured to determine a first calibration sequence;

[0304] The transceiver unit 1120 is configured to send a first calibration sequence through one antenna among the M antennas, and receive data through other M-1 antennas among the M antennas except one antenna, so as to obtain multiple second calibration sequences;

[0305] The calibration processing unit 1130 is configured to perform calibration processing on the M antennas according to the first calibration sequence and the plurality of second calibration sequences.

[0306] In one implementation, the transceiver unit 1120 is specifically configured to:

[0307] Sending a first calibration sequence through an i-th antenna among the M antennas, and receiving data through other M-1 antennas among the M antennas except the i-th antenna, so as to obtain M-1 second calibration sequences;

[0308] Here, i is sequentially 1, 2, ..., M until M*(M-1) second calibration sequences are obtained, and the plurality of second calibration sequences are M*(M-1) second calibration sequences.

[0309] In one implementation, the determining unit 1110 is specifically configured to:

[0310] Determine frequency domain mapping location and initial calibration sequence;

[0311] Mapping the initial calibration sequence to a frequency domain mapping position to obtain a third calibration sequence;

[0312] Perform time-frequency transformation on the third calibration sequence to obtain a first calibration sequence.

[0313] In one implementation, the determining unit 1110 obtains the third calibration sequence by the following formula:

[0314]

[0315] in, For the third calibration sequence, is an integer greater than or equal to 1 and less than or equal to N*12; n1 is the frequency domain mapping position, n2 is an integer greater than or equal to 1 and less than or equal to 12; S TX (k) is an initial calibration sequence, k is an integer greater than or equal to 1 and less than or equal to N, and N is the number of resource blocks in the system bandwidth.

[0316] In one implementation, the calibration processing unit 1130 is specifically configured to:

[0317] Performing time-frequency transformation processing on the plurality of second calibration sequences respectively to obtain a plurality of fourth calibration sequences;

[0318] Demapping the plurality of fourth calibration sequences respectively according to the frequency domain mapping positions to obtain a plurality of fifth calibration sequences;

[0319] The M antennas are calibrated according to an initial calibration sequence corresponding to the first calibration sequence and a plurality of fifth calibration sequences.

[0320] In one implementation, for any fourth calibration sequence, the calibration processing unit 1130 obtains the corresponding fifth calibration sequence by the following formula:

[0321]

[0322] in, is the fifth calibration sequence, sel is the number of the antenna that sends the first calibration sequence; n1 is the frequency domain mapping position, and n1 is an integer greater than or equal to 1 and less than or equal to 12; For the fourth calibration sequence, is an integer greater than or equal to 1 and less than or equal to N*12, N is the number of resource blocks in the system bandwidth, and m is the number of the antenna for data reception.

[0323] In one implementation, the calibration processing unit 1130 is specifically configured to:

[0324] Determining a plurality of channel estimation matrices according to the initial calibration sequence and a plurality of fifth calibration sequences;

[0325] Determining a plurality of calibration factors based on a plurality of channel estimation matrices;

[0326] The M antennas are calibrated according to the multiple calibration factors.

[0327] In one implementation, the calibration processing unit 1130 is specifically configured to:

[0328] Determining a plurality of reference antennas among the M antennas;

[0329] Determining a plurality of target channel estimation matrices among a plurality of channel estimation matrices according to a plurality of reference antennas;

[0330] A plurality of calibration factors are determined based on a plurality of target channel estimation matrices.

[0331] It should be noted that the division of units in the embodiments of the present application is schematic and is only a logical function division. There may be other division methods in actual implementation. In addition, each functional unit in each embodiment of the present application may be integrated into a processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0332] If the above-mentioned 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 processor-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 to enable a computer device (which can be a personal computer, server, or network device, etc.) or a processor (processor) to perform all or part of the steps of each embodiment method of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk and other media that can store program code.

[0333] It should be noted here that the above-mentioned device provided in the present application can implement all the method steps implemented in the above-mentioned method embodiment, and can achieve the same technical effect. The parts and beneficial effects of this embodiment that are the same as the method embodiment will not be described in detail here.

[0334] An embodiment of the present application further provides a processor-readable storage medium, wherein the processor-readable storage medium stores a computer program, and the computer program is used to enable a processor to execute the method described in any one of the above method embodiments.

[0335] The processor-readable storage medium can be any available medium or data storage device that can be accessed by a computer, including but not limited to magnetic storage (such as floppy disks, hard disks, magnetic tapes, magneto-optical disks (MO), etc.), optical storage (such as CD, DVD, BD, HVD, etc.), and semiconductor storage (such as ROM, EPROM, EEPROM, non-volatile memory (NAND FLASH), solid-state drive (SSD)), etc.

[0336] An embodiment of the present application also provides a computer program product, including a computer program, which implements the method described in any one of the above method embodiments when the computer program is executed by a processor.

[0337] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) that contain computer-usable program code.

[0338] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer executable instructions. These computer executable instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0339] These processor executable instructions may also be stored in a processor readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the processor readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0340] These processor-executable instructions may also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for executing on the computer or other programmable device to implement the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0341] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. An antenna calibration method, characterized in that: Applied to a network device, the network device is provided with M antennas, where M is a positive integer greater than 1, and the method comprises: determining a first calibration sequence; Sending the first calibration sequence through one antenna among the M antennas, and receiving data through other M-1 antennas among the M antennas except the one antenna, so as to obtain a plurality of second calibration sequences; The M antennas are calibrated according to the first calibration sequence and the plurality of second calibration sequences.

2. The method according to claim 1, characterized in that: The sending of the first calibration sequence through one antenna among the M antennas, and receiving data through other M-1 antennas among the M antennas except the one antenna, to obtain a plurality of second calibration sequences, includes: Sending the first calibration sequence through an i-th antenna among the M antennas, and receiving data through other M-1 antennas among the M antennas except the i-th antenna, so as to obtain M-1 second calibration sequences; The i is sequentially 1, 2, ..., M until M*(M-1) second calibration sequences are obtained, and the multiple second calibration sequences are the M*(M-1) second calibration sequences.

3. The method according to claim 1 or 2, characterized in that: The determining of the first calibration sequence comprises: Determine frequency domain mapping location and initial calibration sequence; Mapping the initial calibration sequence to the frequency domain mapping position to obtain a third calibration sequence; Perform time-frequency transformation on the third calibration sequence to obtain the first calibration sequence.

4. The method according to claim 3, characterized in that Mapping the initial calibration sequence to the frequency domain mapping position to obtain a third calibration sequence includes: The third calibration sequence is obtained by the following formula: in, For the third calibration sequence, is an integer greater than or equal to 1 and less than or equal to N*12; n1 is the frequency domain mapping position, and n1 is an integer greater than or equal to 1 and less than or equal to 12; S TX (k) is the initial calibration sequence, k is an integer greater than or equal to 1 and less than or equal to N, and N is the number of resource blocks in the system bandwidth.

5. The method according to claim 4, characterized in that The performing calibration processing on the M antennas according to the first calibration sequence and the plurality of second calibration sequences includes: Performing time-frequency transformation processing on the multiple second calibration sequences respectively to obtain multiple fourth calibration sequences; Demapping the plurality of fourth calibration sequences respectively according to the frequency domain mapping positions to obtain a plurality of fifth calibration sequences; The M antennas are calibrated according to the initial calibration sequence and the multiple fifth calibration sequences corresponding to the first calibration sequence.

6. The method according to claim 5, characterized in that The demapping the plurality of fourth calibration sequences respectively according to the frequency domain mapping positions to obtain a plurality of fifth calibration sequences comprises: For any fourth calibration sequence, the corresponding fifth calibration sequence is obtained by the following formula: in, is the fifth calibration sequence, sel is the number of the antenna sending the first calibration sequence; n1 is the frequency domain mapping position, and n1 is an integer greater than or equal to 1 and less than or equal to 12; is the fourth calibration sequence, is an integer greater than or equal to 1 and less than or equal to N*12, N is the number of resource blocks in the system bandwidth, and m is the number of the antenna for data reception.

7. The method according to claim 5, characterized in that The performing calibration processing on the M antennas according to the initial calibration sequence and the plurality of fifth calibration sequences corresponding to the first calibration sequence includes: Determining a plurality of channel estimation matrices according to the initial calibration sequence and the plurality of fifth calibration sequences; determining a plurality of calibration factors based on the plurality of channel estimation matrices; The M antennas are calibrated according to the multiple calibration factors.

8. The method according to claim 7, characterized in that The determining a plurality of calibration factors according to the plurality of channel estimation matrices comprises: Determining a plurality of reference antennas among the M antennas; Determining a plurality of target channel estimation matrices among the plurality of channel estimation matrices according to the plurality of reference antennas; The plurality of calibration factors are determined according to the plurality of target channel estimation matrices.

9. An antenna calibration device, characterized in that: Applied to a network device, the network device is provided with M antennas, where M is a positive integer greater than 1, and the device comprises: A memory for storing a computer program; a transceiver for transmitting and receiving data under the control of a processor; and the processor for reading the computer program in the memory and performing the following operations: determining a first calibration sequence; Sending the first calibration sequence through one antenna among the M antennas, and receiving data through other M-1 antennas among the M antennas except the one antenna, so as to obtain a plurality of second calibration sequences; The M antennas are calibrated according to the first calibration sequence and the plurality of second calibration sequences.

10. The device according to claim 9, characterized in that The processor is specifically configured to perform the following operations: Sending the first calibration sequence through an i-th antenna among the M antennas, and receiving data through other M-1 antennas among the M antennas except the i-th antenna, so as to obtain M-1 second calibration sequences; The i is sequentially 1, 2, ..., M until M*(M-1) second calibration sequences are obtained, and the multiple second calibration sequences are the M*(M-1) second calibration sequences.

11. The device according to claim 9 or 10, characterized in that The processor is specifically configured to perform the following operations: Determine frequency domain mapping location and initial calibration sequence; Mapping the initial calibration sequence to the frequency domain mapping position to obtain a third calibration sequence; Perform time-frequency transformation on the third calibration sequence to obtain the first calibration sequence.

12. The device according to claim 11, characterized in that The processor obtains the third calibration sequence by the following formula: in, For the third calibration sequence, is an integer greater than or equal to 1 and less than or equal to N*12; n1 is the frequency domain mapping position, and n1 is an integer greater than or equal to 1 and less than or equal to 12; S TX (k) is the initial calibration sequence, k is an integer greater than or equal to 1 and less than or equal to N, and N is the number of resource blocks in the system bandwidth.

13. The device according to claim 12, characterized in that The processor is specifically configured to perform the following operations: Performing time-frequency transformation processing on the multiple second calibration sequences respectively to obtain multiple fourth calibration sequences; Demapping the plurality of fourth calibration sequences respectively according to the frequency domain mapping positions to obtain a plurality of fifth calibration sequences; The M antennas are calibrated according to the initial calibration sequence and the multiple fifth calibration sequences corresponding to the first calibration sequence.

14. The device according to claim 13, characterized in that For any fourth calibration sequence, the processor obtains the corresponding fifth calibration sequence by the following formula: in, is the fifth calibration sequence, sel is the number of the antenna sending the first calibration sequence; n1 is the frequency domain mapping position, and n1 is an integer greater than or equal to 1 and less than or equal to 12; is the fourth calibration sequence, is an integer greater than or equal to 1 and less than or equal to N*12, N is the number of resource blocks in the system bandwidth, and m is the number of the antenna for data reception.

15. The device according to claim 13, characterized in that The processor is specifically configured to perform the following operations: Determining a plurality of channel estimation matrices according to the initial calibration sequence and the plurality of fifth calibration sequences; determining a plurality of calibration factors based on the plurality of channel estimation matrices; The M antennas are calibrated according to the multiple calibration factors.

16. The device according to claim 15, characterized in that The processor is specifically configured to perform the following operations: Determining a plurality of reference antennas among the M antennas; Determining a plurality of target channel estimation matrices among the plurality of channel estimation matrices according to the plurality of reference antennas; The plurality of calibration factors are determined according to the plurality of target channel estimation matrices.

17. An antenna calibration device, characterized in that: Applied to a network device, the network device is provided with M antennas, where M is a positive integer greater than 1, and the device comprises: a determining unit, configured to determine a first calibration sequence; a transceiver unit, configured to send the first calibration sequence through one antenna among the M antennas, and receive data through other M-1 antennas among the M antennas except the one antenna, so as to obtain a plurality of second calibration sequences; A calibration processing unit is used to perform calibration processing on the M antennas according to the first calibration sequence and the multiple second calibration sequences.

18. A processor-readable storage medium, characterized in that: The processor-readable storage medium stores a computer program, and the computer program is used to enable the processor to execute the method according to any one of claims 1 to 8.

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