Uplink signal frequency offset compensation method and device, access network equipment and storage medium

Abstract

The invention discloses a frequency offset compensation method and device of an uplink signal, access network equipment and a storage medium, and relates to the technical field of communication. The specific implementation scheme is as follows: receiving an uplink signal sent by a target terminal; acquiring an initial phase rotation angle corresponding to the uplink signal; determining a candidate phase rotation angle according to the initial phase rotation angle and the maximum phase rotation angle; obtaining the SNR of a frequency domain signal corresponding to a time domain signal on a pilot symbol in the uplink signal under each candidate phase rotation angle; determining a target frequency offset according to the SNR of the frequency domain signal under each candidate phase rotation angle; and performing frequency offset compensation on the uplink signal according to the target frequency offset. In conclusion, the initial phase rotation angle is corrected by using the maximum phase rotation angle to obtain the candidate phase rotation angles, and the final target frequency offset is calculated based on the SNR of the frequency domain signal of the pilot frequency symbol under each candidate phase rotation angle, so that the accuracy of frequency offset calculation can be improved, the frequency offset estimation range can be improved, and the application scenarios of multiple columns of pilot frequencies can be increased.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a method, device, access network equipment and storage medium for frequency offset compensation of an uplink signal. Background Art

[0002] At present, the frequency offset can be estimated by using the phase difference between multiple columns of pilot samples (i.e., data samples on multiple columns of pilot symbols). Taking the number of pilot symbols as 2 as an example, assuming that the position indexes of the two columns of pilot symbols are l and 0 and l 1 The time interval between two adjacent OFDM (Orthogonal Frequency Division Multiplexing) symbols is Δt, and the relationship between the phase interval (i.e., phase rotation angle) Δθ between two columns of pilot symbols and the frequency offset Δf is: Δθ=2*π*Δf*(l 1 -l 0 )Δt. The period of the exp function is 2π, and the range of the phase rotation angle Δθ is within [-π,π]. Therefore, the maximum frequency discrimination range (or frequency deviation range) is: -π<2*π*Δf*(l 1 -l 0 )Δt≤π.

[0003] For the LTE (Long Term Evolution) system, there are only two columns of pilot symbols, namely OFDM symbol 3 and OFDM symbol 10. There are 14 OFDM symbols in one subframe, and the transmission time of one subframe is 1ms (milliseconds). The time interval between two adjacent OFDM symbols is The maximum frequency offset range that the LTE system can estimate is: That is, -1000 Hz<Δf≤1000 Hz (Hertz).

[0004] In the scenario where the terminal device moves at high speed, such as when the terminal device moves at a speed of 350 km / h (kilometers per hour), the actual frequency offset can reach 2268 Hz, which exceeds the frequency offset estimation range of two columns of pilot symbols. Therefore, in the scenario where the terminal device moves at high speed, the existing frequency offset estimation scheme is not applicable. Summary of the invention

[0005] The present application provides a method, device, access network equipment and storage medium for frequency offset compensation of an uplink signal.

[0006] According to one aspect of the present application, a method for frequency offset compensation of an uplink signal is provided, which is applied to an access network device, and the method comprises: receiving an uplink signal sent by a target terminal, and obtaining an initial phase rotation angle corresponding to the uplink signal; wherein the uplink signal comprises a time domain signal on at least one pilot symbol; determining at least one candidate phase rotation angle based on the initial phase rotation angle and a set maximum phase rotation angle; obtaining the SNR of a frequency domain signal corresponding to the time domain signal on the pilot symbol at each candidate phase rotation angle; determining a target frequency offset based on the SNR of the frequency domain signal at each candidate phase rotation angle, and performing frequency offset compensation on the uplink signal based on the target frequency offset.

[0007] As a possible implementation method, the number of pilot symbols is multiple, and the initial phase rotation angle corresponding to the uplink signal is obtained, including: performing FFT on the time domain signals on the multiple pilot symbols respectively to obtain multiple frequency domain signals; wherein the frequency domain signal includes frequency domain sampling points corresponding to multiple subcarriers; according to the frequency domain sampling points of the same subcarrier in the multiple frequency domain signals, determining the intermediate value corresponding to the same subcarrier; and determining the initial phase rotation angle according to the average of the intermediate values ​​of the multiple subcarriers.

[0008] As a possible implementation method, the SNR of the frequency domain signal corresponding to the time domain signal on the pilot symbol at each candidate phase rotation angle is obtained, including: obtaining a first channel estimation result of the frequency domain signal at each candidate phase rotation angle; performing inter-carrier interference (ICI) elimination processing on the first channel estimation result at each candidate phase rotation angle respectively to obtain a second channel estimation result at each candidate phase rotation angle; and determining the SNR of the frequency domain signal at each candidate phase rotation angle according to the second channel estimation result at each candidate phase rotation angle.

[0009] As a possible implementation method, obtaining the first channel estimation result of the frequency domain signal at each candidate phase rotation angle includes: determining a candidate frequency offset according to any candidate phase rotation angle; performing channel estimation on the frequency domain signal based on the candidate frequency offset, and obtaining the first channel estimation result of the frequency domain signal at any candidate phase rotation angle.

[0010] As a possible implementation method, the number of pilot symbols is multiple, and the candidate frequency offset is determined according to any candidate phase rotation angle, including: obtaining the index difference between the position indexes of multiple pilot symbols; obtaining the transmission duration of the pilot symbols; taking the product of the index difference and the transmission duration as the first intermediate coefficient; and determining the candidate frequency offset according to the ratio of any candidate phase rotation angle to the first intermediate coefficient.

[0011] As a possible implementation method, the target frequency deviation is determined according to the SNR of the frequency domain signal at each candidate phase rotation angle, including: determining the target phase rotation angle from each candidate phase rotation angle according to the SNR of the frequency domain signal at each candidate phase rotation angle; determining the target frequency deviation according to the target phase rotation angle.

[0012] As a possible implementation, the number of pilot symbols is one, and a target phase rotation angle is determined from each candidate phase rotation angle according to the SNR of the frequency domain signal at each candidate phase rotation angle, including: taking the candidate phase rotation angle with the largest SNR as the target phase rotation angle.

[0013] As a possible implementation method, the number of pilot symbols is multiple, and a target phase rotation angle is determined from each candidate phase rotation angle based on the SNR of the frequency domain signal at each candidate phase rotation angle, including: for any candidate phase rotation angle, taking the average of the SNRs of the frequency domain signal corresponding to the time domain signals on multiple pilot symbols at any candidate phase rotation angle as the target SNR of any candidate phase rotation angle; and taking the candidate phase rotation angle with the largest target SNR as the target phase rotation angle.

[0014] As a possible implementation method, at least one candidate phase rotation angle is determined based on an initial phase rotation angle and a set maximum phase rotation angle, including: obtaining at least one first setting value; wherein the first setting value is an integer; for any first setting value, taking the product of any first setting value and the maximum phase rotation angle as a second intermediate coefficient; and taking the sum of the second intermediate coefficient and the initial phase rotation angle as a candidate phase rotation angle.

[0015] As a possible implementation method, at least one candidate phase conversion angle is determined based on an initial phase rotation angle and a set maximum phase rotation angle, including: determining whether the initial phase rotation angle is a positive number; if the initial phase rotation angle is not a positive number, obtaining at least one second set value; wherein the second set value is a natural number; for any second set value, taking the product of any second set value and the maximum phase rotation angle as a third intermediate coefficient; and taking the sum of the third intermediate coefficient and the initial phase rotation angle as a candidate phase rotation angle.

[0016] As a possible implementation method, at least one candidate phase change angle is determined based on an initial phase rotation angle and a set maximum phase rotation angle, and the method also includes: if the initial phase rotation angle is a positive number, obtaining at least one third set value; wherein the third set value is a negative number of the second set value; for any third set value, taking the product of any third set value and the maximum phase rotation angle as a fourth intermediate coefficient; and taking the sum of the fourth intermediate coefficient and the initial phase rotation angle as a candidate phase rotation angle.

[0017] According to another aspect of the present application, there is provided an access network device, including a memory, a transceiver, and a processor;

[0018] A memory for storing computer programs; a transceiver for transmitting and receiving data under the control of a processor; a processor for reading the computer program in the memory and performing the following operations: receiving an uplink signal sent by a target terminal and obtaining an initial phase rotation angle corresponding to the uplink signal; wherein the uplink signal includes a time domain signal on at least one pilot symbol; determining at least one candidate phase shift angle according to the initial phase rotation angle and a set maximum phase rotation angle; obtaining a signal-to-noise ratio (SNR) of a frequency domain signal corresponding to the time domain signal on the pilot symbol at each candidate phase rotation angle; determining a target frequency deviation according to the SNR of the frequency domain signal at each candidate phase rotation angle, and performing frequency deviation compensation on the uplink signal according to the target frequency deviation.

[0019] As a possible implementation method, the number of pilot symbols is multiple, and the processor executes to obtain the initial phase rotation angle corresponding to the uplink signal, specifically: performing fast Fourier transform FFT on the time domain signals on the multiple pilot symbols respectively to obtain multiple frequency domain signals; wherein the frequency domain signal includes frequency domain sampling points corresponding to multiple subcarriers; according to the frequency domain sampling points of the same subcarrier in the multiple frequency domain signals, determining the intermediate value corresponding to the same subcarrier; and determining the initial phase rotation angle according to the average of the intermediate values ​​of the multiple subcarriers.

[0020] As a possible implementation method, the processor executes to obtain the signal-to-noise ratio SNR of the frequency domain signal corresponding to the time domain signal on the pilot symbol at each candidate phase rotation angle, specifically: obtain the first channel estimation result of the frequency domain signal at each candidate phase rotation angle; perform inter-carrier interference (ICI) elimination processing on the first channel estimation result at each candidate phase rotation angle respectively to obtain the second channel estimation result at each candidate phase rotation angle; determine the SNR of the frequency domain signal at each candidate phase rotation angle according to the second channel estimation result at each candidate phase rotation angle.

[0021] As a possible implementation method, the processor executes to obtain the first channel estimation result of the frequency domain signal at each candidate phase rotation angle, specifically: according to any candidate phase rotation angle, determine the candidate frequency offset; based on the candidate frequency offset, perform channel estimation on the frequency domain signal to obtain the first channel estimation result of the frequency domain signal at any candidate phase rotation angle.

[0022] As a possible implementation method, the number of pilot symbols is multiple, and the processor determines the candidate frequency offset based on any candidate phase rotation angle, specifically: obtaining the index difference between the position indexes of multiple pilot symbols; obtaining the transmission duration of the pilot symbols; taking the product of the index difference and the transmission duration as the first intermediate coefficient; and determining the candidate frequency offset based on the ratio of any candidate phase rotation angle to the first intermediate coefficient.

[0023] As a possible implementation method, the processor determines the target frequency deviation based on the SNR of the frequency domain signal at each candidate phase rotation angle, specifically: determines the target phase rotation angle from each candidate phase rotation angle based on the SNR of the frequency domain signal at each candidate phase rotation angle; determines the target frequency deviation based on the target phase rotation angle.

[0024] As a possible implementation method, the number of pilot symbols is one, and the processor determines the target phase rotation angle from each candidate phase rotation angle based on the SNR of the frequency domain signal at each candidate phase rotation angle, specifically: taking the candidate phase rotation angle with the largest SNR as the target phase rotation angle.

[0025] As a possible implementation method, the number of pilot symbols is multiple, and the processor determines the target phase rotation angle from each candidate phase rotation angle based on the SNR of the frequency domain signal at each candidate phase rotation angle. Specifically, for any candidate phase rotation angle, the average of the SNRs of the frequency domain signal corresponding to the time domain signals on multiple pilot symbols at any candidate phase rotation angle is used as the target SNR of any candidate phase rotation angle; and the candidate phase rotation angle with the largest target SNR is used as the target phase rotation angle.

[0026] As a possible implementation method, the processor determines at least one candidate phase conversion angle based on the initial phase rotation angle and the set maximum phase rotation angle, specifically: obtaining at least one first setting value; wherein the first setting value is an integer; for any first setting value, taking the product of any first setting value and the maximum phase rotation angle as the second intermediate coefficient; taking the sum of the second intermediate coefficient and the initial phase rotation angle as the candidate phase rotation angle.

[0027] As a possible implementation method, the processor determines at least one candidate phase conversion angle based on the initial phase rotation angle and the set maximum phase rotation angle, specifically: judging whether the initial phase rotation angle is a positive number; if the initial phase rotation angle is not a positive number, obtaining at least one second set value; wherein the second set value is a natural number; for any second set value, taking the product of any second set value and the maximum phase rotation angle as a third intermediate coefficient; taking the sum of the third intermediate coefficient and the initial phase rotation angle as a candidate phase rotation angle.

[0028] As a possible implementation method, the processor determines at least one candidate phase conversion angle based on the initial phase rotation angle and the set maximum phase rotation angle, specifically: if the initial phase rotation angle is a positive number, obtain at least one third set value; wherein the third set value is a negative number of the second set value; for any third set value, the product of any third set value and the maximum phase rotation angle is used as a fourth intermediate coefficient; and the sum of the fourth intermediate coefficient and the initial phase rotation angle is used as a candidate phase rotation angle.

[0029] According to another aspect of the present application, a frequency offset compensation device for an uplink signal is provided, which is applied to an access network device, and the device includes:

[0030] A first processing unit is configured to receive an uplink signal sent by a target terminal and obtain an initial phase rotation angle corresponding to the uplink signal; wherein the uplink signal includes a time domain signal on at least one pilot symbol;

[0031] A determination unit, configured to determine at least one candidate phase rotation angle according to an initial phase rotation angle and a set maximum phase rotation angle;

[0032] An acquisition unit, used to acquire a signal-to-noise ratio (SNR) of a frequency domain signal corresponding to a time domain signal on the pilot symbol at each candidate phase rotation angle;

[0033] The second processing unit is used to determine the target frequency offset according to the SNR of the frequency domain signal at each candidate phase rotation angle, and perform frequency offset compensation on the uplink signal according to the target frequency offset.

[0034] According to another aspect of the present application, a processor-readable storage medium is provided, wherein the processor-readable storage medium stores a computer program, wherein the computer program is used to enable the processor to execute the frequency offset compensation method for the aforementioned uplink signal.

[0035] According to another aspect of the present application, a computer program product is provided. When an instruction processor in the computer program product executes, the frequency offset compensation method for the above-mentioned uplink signal is executed.

[0036] The present application has the following technical effects: by receiving the uplink signal sent by the terminal device, and obtaining the initial phase rotation angle corresponding to the uplink signal; determining at least one candidate phase rotation angle according to the initial phase rotation angle and the set maximum phase rotation angle; obtaining the SNR of the frequency domain signal corresponding to the time domain signal on the pilot symbol in the uplink signal at each candidate phase rotation angle; determining the target frequency deviation according to the SNR of the frequency domain signal at each candidate phase rotation angle, and performing frequency deviation compensation on the uplink signal according to the target frequency deviation. In summary, considering that when the mobile speed of the terminal device increases or is high, a phase flip may occur. In the present application, the maximum phase rotation angle is used to correct the initial phase rotation angle to obtain at least one candidate phase rotation angle, and the final target frequency deviation is calculated based on the SNR of the frequency domain signal corresponding to the time domain signal on the pilot symbol at each candidate phase rotation angle. This can improve the accuracy of the frequency deviation calculation, increase the frequency deviation estimation range, and increase the application scenarios of multiple columns of pilots.

[0037] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present application, nor is it intended to limit the scope of the present application. Other features of the present application will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings are used to better understand the present solution and do not constitute a limitation of the present application.

[0039] Figure 1 It is a flow chart of a frequency offset compensation method for an uplink signal provided in an embodiment of the present application;

[0040] Figure 2 It is a flow chart of another method for compensating frequency offset of an uplink signal provided in an embodiment of the present application;

[0041] Figure 3 It is a flow chart of another method for compensating frequency offset of an uplink signal provided in an embodiment of the present application;

[0042] Figure 4 It is a flow chart of another method for compensating frequency offset of an uplink signal provided in an embodiment of the present application;

[0043] Figure 5 It is a flow chart of another method for compensating frequency offset of an uplink signal provided in an embodiment of the present application;

[0044] Figure 6 This is a phase rotation diagram provided in the embodiment of the present application. Figure 1 ;

[0045] Figure 7 This is a phase rotation diagram provided in the embodiment of the present application. Figure 2 ;

[0046] Figure 8 is a schematic diagram of the relative relationship between the high-speed railway and two communities provided in an embodiment of the present application;

[0047] Fig. 9 This is a phase rotation diagram provided in the embodiment of the present application. Figure 3 ;

[0048] Fig.10 It is a schematic diagram of a demodulated constellation diagram obtained by processing with the solution of the present application provided in an embodiment of the present application and a demodulated constellation diagram obtained by processing with the original solution in the related art;

[0049] Fig.11 It is a structural diagram of an access network device provided according to an embodiment of the present application;

[0050] Fig.12 It is a structural schematic diagram of a frequency offset compensation device for an uplink signal provided in an embodiment of the present application. DETAILED DESCRIPTION

[0051] 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.

[0052] That is, the term "and / or" in the embodiments of the present application describes the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B may represent: 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.

[0053] At present, in the scenario of high-speed movement of terminal devices, the speed range that needs to be supported has been increased to 350km / h, so there are more requirements for the number and location of pilot symbols. Due to protocol regulations or resource constraints, when a sufficient number of pilot symbols cannot be configured, the phase rotation angle obtained by frequency offset estimation will exceed the discrimination range of [-π,π], resulting in phase flip. The traditional frequency offset estimation scheme cannot work properly at this time. The following specifically describes the current traditional frequency offset estimation scheme and its limitations.

[0054] Traditional frequency offset estimation scheme: The frequency offset is estimated by using the phase difference between multiple pilot sample points. Taking two pilot symbols as an example, assuming that the position indexes of the two pilot symbols are l 0 and l 1, the time interval between two adjacent OFDM symbols is Δt, and the relationship between the phase interval Δθ between two columns of pilot symbols and the frequency offset Δf is as follows:

[0055] Δθ=2*π*Δf*(l 1 -l 0 )Δt; (1)

[0056] The period of the exp function is 2π, and the phase rotation angle is in the range of [-π,π]. Therefore, the maximum frequency discrimination range (or frequency deviation range) is: -π<2*π*Δf*(l 1 -l 0 )Δt≤π, that is,

[0057] For the LTE system, there are only two columns of pilot symbols, OFDM symbol 3 and OFDM symbol 10. There are 14 OFDM symbols in one subframe, and the transmission time of one subframe is 1ms. The time interval between two adjacent OFDM symbols is In this way, the maximum frequency offset range that the LTE system can estimate can be calculated as: That is, -1000 Hz<Δf≤1000 Hz.

[0058] When the terminal device moves at a speed of 350 km / h and the central frequency point of the access network device (such as a base station) is f c When the frequency is 3.5 GHz, according to the relationship between frequency deviation and speed: (where c is the speed of light, v is the moving speed (m / s, meters per second), and f c is the center frequency, f is the frequency deviation), it can be seen that the frequency deviation can reach (3.5×10 9 *350×10 3 / 3600) / (3×10 8 )≈1134Hz. Considering that the center frequency of the terminal device and the access network device are aligned through SSB (Synchronization Signal / PBCH (Physical Broadcast Channel) Block), due to the movement of the terminal device, the center frequency of the terminal device is f c +f, and the terminal device sends PUSCH (Physical Uplink Shared Channel) to the access network device. Due to the movement of the terminal device, the central frequency of the signal received by the access network device is f c +f+f, thus, the actual receiving frequency deviation of the access network equipment is 2f, which is twice the theoretical frequency deviation.

[0059] Therefore, when the mobile speed of the terminal device reaches 350 km / h, the actual frequency deviation of the access network device can reach 2268 Hz, which exceeds the frequency deviation estimation range of the two columns of pilot signals.

[0060] In summary, the existing frequency offset estimation scheme is affected by the number of pilot symbols and the position interval between pilot symbols, and supports different frequency offset estimation ranges. For the LTE system, the number of pilot symbols and the position interval between pilot symbols are fixed. For the NR (New Radio) system, the configuration of pilot symbols is restricted by the protocol, and considering issues such as resource utilization, there are also restrictions on the number of pilot symbols and the position interval between pilot symbols. When the mobile speed of the terminal device increases, the frequency offset will be too large and exceed the frequency offset estimation range, resulting in phase flipping.

[0061] In response to at least one of the above-mentioned problems, the present application provides a method, apparatus, access network equipment and storage medium for frequency offset compensation of an uplink signal.

[0062] The following describes the frequency offset compensation method, device, access network device and storage medium of the uplink signal of the present embodiment with reference to the accompanying drawings. Before explaining the embodiments of the present application in detail, for ease of understanding, the technical terms involved in the present application are first introduced:

[0063] The initial phase rotation angle refers to the phase rotation angle obtained by performing a coarse frequency offset estimation (or coarse-grained frequency offset estimation) on the uplink signal.

[0064] The maximum phase rotation angle refers to a preset maximum phase rotation angle. For example, the maximum phase rotation angle may be 2π.

[0065] The candidate phase rotation angle refers to a phase rotation angle obtained by correcting the initial phase rotation angle according to the maximum phase rotation angle.

[0066] The frequency domain signal is obtained by performing FFT (Fast Fourier Transform) on the time domain signal. The frequency domain signal may include multiple frequency domain samples (or frequency domain sampling points), the number of frequency domain samples is less than or equal to the FFT length, and each frequency domain sample corresponds to a subcarrier.

[0067] SNR is the abbreviation of Signal-Noise Ratio.

[0068] ICI is the abbreviation of Inter Carrier Interference.

[0069] RE is the abbreviation of resource element or resource particle.

[0070] A data symbol refers to a symbol that sends useful information or useful signals.

[0071] The pilot symbol refers to the symbol for sending the pilot, which is used to assist in demodulation of the signal.

[0072] The first setting value is a pre-set value, wherein the first setting value is an integer. For example, the first setting value can be: -n 1 ,-n 1 +1,…,0,…,n 1 -1,n 1 , where n 1 is an integer, n 1 Different values ​​can be set according to different application scenarios. For example, n can be determined according to the frequency deviation range tolerated by the access network equipment. 1 The specific value of .

[0073] The second set value is also a preset value, wherein the second set value is a natural number, for example, the second set value can be: 0, 1, 2,….

[0074] The third setting value is also a preset value, wherein the third setting value is a negative number of the second setting value. For example, the third setting value can be: 0, -1, -2, ...

[0075] Figure 1 It is a flow chart of a frequency offset compensation method for an uplink signal provided in an embodiment of the present application.

[0076] The frequency offset compensation method for an uplink signal in the embodiment of the present application can be applied to an access network device.

[0077] Herein, the access network device is taken as an example as a base station. The base station may include multiple cells that provide services for the terminal device. 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 access 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 access network device may also coordinate the attribute management of the air interface. For example, the access network device involved in the embodiments of the present application may be an access network device (Base TransceiverStation, BTS) in the Global System for Mobile communications (GSM) or Code Division Multiple Access (CDMA), or an access network device (NodeB) in Wide-band Code Division Multiple Access (WCDMA), or an evolutionary access network device (eNB or e-NodeB) in the long term evolution (LTE) system, a 5G base station (gNB) in the 5G network architecture (next generation system), or a 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 access 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.

[0078] The terminal device may be a device that provides voice and / or data connectivity to a user, a handheld device with a wireless connection function, or other processing devices connected to a wireless modem. In different systems, the names of the terminal devices may also be different. For example, in a 5G system, the terminal device may be called a user equipment (UE). The wireless terminal device may communicate with one or more core networks (CN) via a radio access network (RAN). The wireless terminal device may be a mobile terminal device, such as a mobile phone (or "cellular" phone) and a computer with a mobile terminal device. For example, it may be a portable, pocket-sized, handheld, computer-built-in or vehicle-mounted mobile device that exchanges language and / or data with a wireless access network. For example, personal communication service (PCS) phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (PDA) and other devices. The wireless terminal device may also be referred to as a system, a subscriber unit, a subscriber station, a mobile station, a mobile station, a remote station, an access point, a remote terminal device, an access terminal device, a user terminal device, a user agent, and a user device, but is not limited in the embodiments of the present application.

[0079] like Figure 1 As shown, the frequency offset compensation method of the uplink signal may include the following steps:

[0080] Step S101, receiving an uplink signal sent by a terminal device, and acquiring an initial phase rotation angle corresponding to the uplink signal; wherein the uplink signal includes a time domain signal on at least one pilot symbol.

[0081] In the embodiment of the present application, the terminal device may be any terminal device located in a service cell of the access network device.

[0082] In the embodiment of the present application, the uplink signal includes but is not limited to a signal transmitted through a channel such as PUSCH and PUCCH (Physical Uplink Control Channel).

[0083] In the embodiment of the present application, the uplink signal may include not only a time domain signal on at least one pilot symbol, but also a time domain signal on multiple data symbols.

[0084] In an embodiment of the present application, the access network device may receive an uplink signal sent by a terminal device, and perform a coarse frequency offset estimation (or coarse-grained frequency offset estimation) on the uplink signal to obtain an initial phase rotation angle.

[0085] Step S102: determining at least one candidate phase rotation angle according to the initial phase rotation angle and the set maximum phase rotation angle.

[0086] In the embodiment of the present application, the initial phase rotation angle may be corrected according to the maximum phase rotation angle to obtain at least one candidate phase rotation angle.

[0087] Step S103: Acquire the SNR of the frequency domain signal corresponding to the time domain signal on the pilot symbol at each candidate phase rotation angle.

[0088] In the embodiment of the present application, FFT may be performed on the time domain signal on the pilot symbol to obtain a frequency domain signal corresponding to the pilot symbol, and the SNR of the frequency domain signal at each candidate phase rotation angle may be calculated.

[0089] Step S104: determine a target frequency offset according to the SNR of the frequency domain signal at each candidate phase rotation angle, and perform frequency offset compensation on the uplink signal according to the target frequency offset.

[0090] In the embodiment of the present application, the target frequency offset can be calculated according to the SNR of the frequency domain signal corresponding to the pilot symbol at each candidate phase rotation angle, and the frequency offset compensation can be performed on the uplink signal according to the target frequency offset.

[0091] The frequency offset compensation method of the uplink signal in the embodiment of the present application is achieved by receiving the uplink signal sent by the terminal device and obtaining the initial phase rotation angle corresponding to the uplink signal; determining at least one candidate phase rotation angle according to the initial phase rotation angle and the set maximum phase rotation angle; obtaining the SNR of the frequency domain signal corresponding to the time domain signal on the pilot symbol in the uplink signal at each candidate phase rotation angle; determining the target frequency offset according to the SNR of the frequency domain signal at each candidate phase rotation angle, and performing frequency offset compensation on the uplink signal according to the target frequency offset. In summary, considering that when the moving speed of the terminal device increases or is relatively high, a phase flip may occur. In the present application, the maximum phase rotation angle is used to correct the initial phase rotation angle to obtain at least one candidate phase rotation angle, and the final target frequency offset is calculated based on the SNR of the frequency domain signal corresponding to the time domain signal on the pilot symbol at each candidate phase rotation angle. This can improve the accuracy of the frequency offset calculation, increase the frequency offset estimation range, and increase the application scenarios of multiple columns of pilots.

[0092] In order to clearly explain how to obtain the initial phase rotation angle corresponding to the uplink signal in the above embodiments of the present application, the present application also proposes a frequency offset compensation method for the uplink signal.

[0093] Figure 2 It is a flow chart of another method for frequency offset compensation of an uplink signal provided in an embodiment of the present application.

[0094] like Figure 2 As shown, the frequency offset compensation method of the uplink signal may include the following steps:

[0095] Step S201: receiving an uplink signal sent by a target terminal, wherein the uplink signal includes time domain signals on multiple pilot symbols.

[0096] For the explanation of step S201, please refer to the relevant description in any embodiment of the present application, which will not be repeated here.

[0097] In the embodiment of the present application, the uplink signal may include time domain signals on multiple pilot symbols. Exemplarily, the number of pilot symbols may be two.

[0098] Step S202: Perform FFT on the time domain signals on multiple pilot symbols respectively to obtain multiple frequency domain signals.

[0099] In the embodiment of the present application, FFT can be performed on the time domain signals on multiple pilot symbols respectively to obtain frequency domain signals corresponding to the multiple pilot symbols, wherein the frequency domain signal of each pilot symbol may include frequency domain samples corresponding to multiple subcarriers.

[0100] Step S203: Determine an intermediate value corresponding to the same subcarrier according to the frequency domain samples of the same subcarrier in the multiple frequency domain signals.

[0101] In the embodiment of the present application, an intermediate value corresponding to the same subcarrier can be calculated based on the frequency domain samples of the same subcarrier in multiple frequency domain signals.

[0102] As an example, assume that the number of pilot symbols is 2, the two pilot symbols are symbols s1 and s2, and the frequency domain sample point corresponding to the i-th subcarrier on the symbol s1 is d s1,i , the frequency domain sample point corresponding to the i-th subcarrier on the marker symbol s2 is d s2,i , the number of marked subcarriers is N re , the intermediate value of the i-th subcarrier may be, for example: d s1,i *conj(d s2,i ), where i is not greater than N re is a positive integer, and conj() means to find the conjugate.

[0103] For example, when the two pilot symbols are symbol 2 and symbol 11, the intermediate value of the i-th subcarrier may be: 2,i *conj(d 11,i ).

[0104] Step S204: determining an initial phase rotation angle according to an average of intermediate values ​​of multiple subcarriers.

[0105] In the embodiment of the present application, the initial phase rotation angle may be determined according to the average of the intermediate values ​​of multiple subcarriers.

[0106] As an example, the initial phase rotation angle is marked as Δθ 0 , Δθ 0 For example, it can be calculated by the following formula:

[0107]

[0108] Among them, angle refers to the angle, that is, d s1,i and d s2,i are all complex numbers, and the intermediate value of each subcarrier is also a complex number. (subsequently marked as S) is also a complex number, and the angle corresponding to the complex number S can be calculated. For example, the complex number S can be converted into polar coordinate form, that is, r(cosO+isinO), where r is the modulus and O is the angle. In this case, O is the initial phase rotation angle.

[0109] For example, when the two pilot symbols are symbol 2 and symbol 11,

[0110] Step S205: determining at least one candidate phase rotation angle according to the initial phase rotation angle and the set maximum phase rotation angle.

[0111] Step S206: Obtain the SNR of the frequency domain signal corresponding to the time domain signal on the pilot symbol at each candidate phase rotation angle.

[0112] Step S207: determine a target frequency offset according to the SNR of the frequency domain signal at each candidate phase rotation angle, and perform frequency offset compensation on the uplink signal according to the target frequency offset.

[0113] The explanation of steps S205 to S207 can be found in the relevant description in any embodiment of the present application and will not be repeated here.

[0114] The frequency offset compensation method for an uplink signal in an embodiment of the present application can effectively calculate the initial phase rotation angle according to the frequency domain samples of the same subcarrier in the frequency domain signals of multiple pilot symbols.

[0115] In order to clearly explain how to obtain the SNR of the frequency domain signal at each candidate phase rotation angle in any embodiment of the present application, the present application also proposes a frequency offset compensation method for an uplink signal.

[0116] Figure 3 It is a flow chart of another method for frequency offset compensation of an uplink signal provided in an embodiment of the present application.

[0117] like Figure 3 As shown, the frequency offset compensation method of the uplink signal may include the following steps:

[0118] Step S301, receiving an uplink signal sent by a target terminal, and acquiring an initial phase rotation angle corresponding to the uplink signal; wherein the uplink signal includes a time domain signal on at least one pilot symbol.

[0119] Step S302: determining at least one candidate phase rotation angle according to the initial phase rotation angle and the set maximum phase rotation angle.

[0120] The explanation of steps S301 to S302 can be found in the relevant description in any embodiment of the present application and will not be repeated here.

[0121] Step S303: Obtain a first channel estimation result of the frequency domain signal at each candidate phase rotation angle.

[0122] In an embodiment of the present application, for any candidate phase rotation angle, a channel estimation result of a frequency domain signal corresponding to a pilot symbol at the candidate phase rotation angle may be calculated, which is recorded as a first channel estimation result in the present application.

[0123] It should be noted that in the scenario where the terminal device moves at high speed, as the frequency offset increases, the inter-carrier interference (ICI) between frequency domain samples (or REs) on different subcarriers in the same OFDM symbol becomes larger and larger. If it is not processed, the SNR of the channel estimation will be seriously reduced. Similarly, if the estimated frequency offset exceeds the range of the demodulation interval, using the wrong frequency offset value for ICI elimination will also significantly reduce the SNR of the channel estimation.

[0124] Due to the large frequency offset, ICI is introduced between frequency domain samples, which reduces the SNR of channel estimation. When there is a frequency offset f, the expression of ICI interference carried in the frequency domain signal is derived as follows:

[0125] Assume that the time domain signal received by the access network device on the lth OFDM symbol is represented as y l [n], where n represents the time domain sample subscript, and the corresponding frequency domain signal is represented by Y l [k], where k represents the subscript of the frequency domain sample point. Equal to ε f ,Right now, Wherein, Δf1 represents SCS (Sub-Carrier Spacing) in the frequency domain. For example, the meaning of each parameter may be summarized as shown in Table 1.

[0126] Table 1 Parameter meaning

[0127]

[0128]

[0129] When there is a frequency deviation, Where j is an imaginary unit, H is the channel (e.g. H[m] is the channel gain or channel response of frequency domain sample point m), and X is the transmitted data of the terminal device (e.g. x l [m] is the frequency domain signal corresponding to the frequency domain sample point m on the lth OFDM symbol sent by the terminal device), and y represents the received data of the access network device (such as y l [n] is the time domain signal corresponding to the time domain sample point n on the lth OFDM symbol received by the access network device), z l [n] represents the noise of time domain sample point n on the lth OFDM symbol. When there is a frequency offset, for the frequency domain sample point m, the phase difference caused by the frequency offset f is 2πfΔt, and the time difference between the position of the time domain sample point n and the position 0 is in, is the transmission time of an OFDM symbol. A total of N data samples are sent in an OFDM symbol, where N is the FFT length. Therefore, the phase difference introduced by the frequency offset f can be written as remember The phase difference introduced by the frequency offset f can be written as Therefore, in the presence of frequency offset, the signal part can be expressed as:

[0130] because in:

[0131]

[0132] Therefore, substituting formula (3) into Y l The calculation formula of [k] can be derived as follows:

[0133]

[0134]

[0135] in, I l [k] is the ICI of other subcarriers to the kth subcarrier due to frequency offset.

[0136] For the frequency domain signal on the pilot symbol, the local base sequence is first decoded before channel estimation. By decoding the local base sequence and demodulating the pilot symbol, information about the channel can be obtained. Assuming that the time domain signal sent by the terminal device on the pilot symbol is S[k] (known by the access network device), the frequency domain signal on the pilot symbol can be expressed as:

[0137]

[0138] Among them, H[k] represents the frequency domain channel experienced by the pilot symbol, I[k] represents the ICI interference introduced by the terminal device movement, and Z[k] represents the noise. The channel estimation result obtained after solving the local base sequence is:

[0139]

[0140] Among them, S[k]*S[k] * =1, and record I[k]′=I[k]*S[k] * , Z[k]′=Z[k]*S[k] * , then the channel estimation result obtained after solving the local basis sequence (referred to as the first channel estimation result in this application) can be written as:

[0141]

[0142] It should be noted that the frequency offset f in each formula in step S303 refers to the frequency offset calculated according to the candidate phase rotation angle.

[0143] Step S304: Perform ICI elimination processing on the first channel estimation results under each candidate phase rotation angle respectively to obtain the second channel estimation results under each candidate phase rotation angle.

[0144] In the embodiment of the present application, ICI elimination processing may be performed on the first channel estimation result at each candidate phase rotation angle to obtain the second channel estimation result at each candidate phase rotation angle.

[0145] For example, I[k]′ in formula (7) may be set to zero to obtain the second channel estimation result.

[0146] Step S305: Determine the SNR of the frequency domain signal at each candidate phase rotation angle according to the second channel estimation result at each candidate phase rotation angle.

[0147] In the embodiment of the present application, for any candidate phase rotation angle, the SNR of the frequency domain signal at the candidate phase rotation angle can be calculated according to the second channel estimation result at the candidate phase rotation angle.

[0148] As an example, when ICI elimination processing is not performed, the following formula can be used to calculate the SNR:

[0149]

[0150] After ICI elimination, the SNR can be calculated using the following formula:

[0151]

[0152] Step S306: determine a target frequency offset according to the SNR of the frequency domain signal at each candidate phase rotation angle, and perform frequency offset compensation on the uplink signal according to the target frequency offset.

[0153] For the explanation of step S306, reference may be made to the relevant description in any embodiment of the present disclosure, and no further details will be given here.

[0154] The frequency offset compensation method for uplink signals in the embodiment of the present application can improve the accuracy of SNR calculation by performing inter-carrier interference (ICI) elimination processing on the channel estimation result.

[0155] In order to clearly explain how to obtain the first channel estimation result of the frequency domain signal at each candidate phase rotation angle in any embodiment of the present application, the present application also proposes a frequency offset compensation method for an uplink signal.

[0156] Figure 4It is a flow chart of another method for frequency offset compensation of an uplink signal provided in an embodiment of the present application.

[0157] like Figure 4 , the frequency offset compensation method of the uplink signal may include the following steps:

[0158] Step S401, receiving an uplink signal sent by a target terminal, and acquiring an initial phase rotation angle corresponding to the uplink signal; wherein the uplink signal includes a time domain signal on at least one pilot symbol.

[0159] Step S402: Determine at least one candidate phase rotation angle according to the initial phase rotation angle and the set maximum phase rotation angle.

[0160] The explanation of steps S401 to S402 can be found in the relevant description in any embodiment of the present application and will not be repeated here.

[0161] Step S403: Determine a candidate frequency offset according to any candidate phase rotation angle.

[0162] In the embodiment of the present application, for any candidate phase rotation angle, a candidate frequency offset may be calculated according to the candidate phase rotation angle.

[0163] In any embodiment of the present application, the candidate frequency offset is calculated, for example, as follows:

[0164] 1. Obtain the index difference between the position indexes of multiple pilot symbols.

[0165] As an example, the number of pilot symbols is 2, and it is assumed that the position indexes of the two columns of pilot symbols are l and 0 and l 1 , where l 0 Less than l 1 , then the index difference can be: l 1 -l 0 .

[0166] For example, when the two pilot symbols are symbol 2 and symbol 11, l 0 =2, l 1 is 11, then the index difference is 9.

[0167] 2. Obtain the transmission duration of the pilot symbol.

[0168] In an embodiment of the present application, the transmission duration of a single column of pilot symbols (or a single OFDM symbol) may be obtained.

[0169] For example, if one subframe has 14 OFDM symbols and the transmission time of one subframe is 1 ms, then the transmission duration can be the time interval Δt between two adjacent OFDM symbols, where:

[0170] 3. The product of the index difference and the transmission duration is used as the first intermediate coefficient.

[0171] In an embodiment of the present application, the product of the index difference and the transmission duration may be used as the first intermediate coefficient.

[0172] 4. Determine the candidate frequency offset based on the ratio of any candidate phase rotation angle to the first intermediate coefficient.

[0173] In the embodiment of the present application, the candidate frequency offset may be determined according to the ratio of the candidate phase rotation angle to the first intermediate coefficient.

[0174] As an example, the above formula (1) can be used to calculate the candidate frequency offset, that is, the candidate phase rotation angle can be substituted into Δθ in formula (1), and the first intermediate coefficient (l 1 -l 0 )Δt is substituted into formula (1), and the calculated Δf is the candidate frequency offset.

[0175] Step S404: performing channel estimation on the frequency domain signal based on the candidate frequency offset to obtain a first channel estimation result of the frequency domain signal under any candidate phase rotation angle.

[0176] In the embodiment of the present application, channel estimation can be performed on the frequency domain signal based on the candidate frequency offset to obtain a first channel estimation result of the frequency domain signal under the above candidate phase rotation angle. For example, the candidate frequency offset can be substituted into f in the above formula (7) to obtain the first channel estimation result.

[0177] Step S405: Perform ICI elimination processing on the first channel estimation result under each candidate phase rotation angle respectively to obtain the second channel estimation result under each candidate phase rotation angle.

[0178] Step S406: Determine the SNR of the frequency domain signal at each candidate phase rotation angle according to the second channel estimation result at each candidate phase rotation angle.

[0179] Step S407: determine a target frequency offset according to the SNR of the frequency domain signal at each candidate phase rotation angle, and perform frequency offset compensation on the uplink signal according to the target frequency offset.

[0180] The explanation of steps S405 to S407 can be found in the relevant description in any embodiment of the present application and will not be repeated here.

[0181] The frequency offset compensation method for the uplink signal in the embodiment of the present application can realize channel estimation of the frequency domain signal based on the candidate frequency offset corresponding to each candidate phase rotation angle, obtain the first channel estimation result of the frequency domain signal under the candidate phase rotation angle, and improve the effectiveness of the calculation of the first channel estimation result.

[0182] In order to clearly explain how the target frequency offset is determined according to the SNR of the frequency domain signal at each candidate phase rotation angle in any embodiment of the present application, the present application also proposes a frequency offset compensation method for an uplink signal.

[0183] Figure 5 It is a flow chart of another method for frequency offset compensation of an uplink signal provided in an embodiment of the present application.

[0184] like Figure 5 As shown, the frequency offset compensation method of the uplink signal may include the following steps:

[0185] Step S501, receiving an uplink signal sent by a target terminal, and acquiring an initial phase rotation angle corresponding to the uplink signal; wherein the uplink signal includes a time domain signal on at least one pilot symbol.

[0186] Step S502: determining at least one candidate phase rotation angle according to the initial phase rotation angle and the set maximum phase rotation angle.

[0187] The explanation of steps S501 to S502 can be found in the relevant description in any embodiment of the present application and will not be repeated here.

[0188] In any embodiment of the present application, the candidate phase rotation angle may be determined, for example, by:

[0189] 1. Obtain at least one first setting value; wherein the first setting value is an integer.

[0190] 2. For any first setting value, the product of any first setting value and the maximum phase rotation angle is used as the second intermediate coefficient.

[0191] In the embodiment of the present application, for any first setting value, the product of the first setting value and the maximum phase rotation angle can be used as the second intermediate coefficient.

[0192] 3. The sum of the second intermediate coefficient and the initial phase rotation angle is used as the candidate phase rotation angle.

[0193] In the embodiment of the present application, the sum of the second intermediate coefficient and the initial phase rotation angle may be used as the candidate phase rotation angle.

[0194] As an example, the maximum phase rotation angle is 2π, and the first setting value is i, where i = -n1 ,-n 1 +1,…,0,…,n 1 -1,n 1 , then the candidate phase rotation angle can be: Δθ 0 +i*2π.

[0195] In any embodiment of the present application, the candidate phase rotation angle may be determined, for example, by:

[0196] 1. Determine whether the initial phase rotation angle is a positive number. If not, execute steps 2 to 4. If yes, execute steps 5 to 7.

[0197] It should be noted that steps 2 to 4 and steps 5 to 7 are two parallel implementation methods. In actual application, only one needs to be executed.

[0198] 2. Obtain at least one second setting value.

[0199] In the embodiment of the present application, when the initial phase rotation angle is not a positive number, at least one second setting value can be obtained, where the second setting value is a natural number.

[0200] 3. For any second setting value, the product of any second setting value and the maximum phase rotation angle is used as the third intermediate coefficient.

[0201] In the embodiment of the present application, for any second setting value, the product of the second setting value and the maximum phase rotation angle can be used as the third intermediate coefficient.

[0202] 4. The sum of the third intermediate coefficient and the initial phase rotation angle is used as the candidate phase rotation angle.

[0203] In the embodiment of the present application, the sum of the third intermediate coefficient and the initial phase rotation angle may be used as the candidate phase rotation angle.

[0204] It should be noted that, assuming that the frequency deviation direction is positive, as the frequency deviation increases, the corresponding phase rotation angle increases continuously. When the phase rotation angle is greater than π, the estimated phase rotation angle flips, such as Figure 6 As shown by the triangle in , the estimated phase rotation angle is negative at this time.

[0205] In order to find the phase reversal law, the unit circle can be expanded as follows: Figure 7 The straight line shown in the figure, triangle 1 is the actual corresponding real phase rotation angle Δθ real , triangle 2 is the estimated phase rotation angle Δθ after flipping est .

[0206] Depend on Figure 7It can be seen that when Δθ real If Δθ does not exceed 2π, real =Δθ est Therefore, in the present application, when the initial phase rotation angle is not a positive number, the initial rotation angle+2π*second setting value may be selected, wherein the second setting value is a non-negative number.

[0207] 5. Obtain at least one third setting value.

[0208] In the embodiment of the present application, when the initial phase rotation angle is a positive number, at least one third setting value can be obtained, wherein the third setting value is a negative number of the second setting value.

[0209] 6. For any third setting value, the product of any third setting value and the maximum phase rotation angle is used as the fourth intermediate coefficient.

[0210] In the embodiment of the present application, for any third setting value, the product of the third setting value and the maximum phase rotation angle can be used as the fourth intermediate coefficient.

[0211] 7. The sum of the fourth intermediate coefficient and the initial phase rotation angle is used as the candidate phase rotation angle.

[0212] In the embodiment of the present application, the sum of the fourth intermediate coefficient and the initial phase rotation angle may be used as the candidate phase rotation angle.

[0213] It should be noted that Figure 6 and Figure 7 Similarly, for the case where the frequency deviation is negative, Δθ real =Δθ est Therefore, in the present application, when the initial phase rotation angle is a positive number, the initial rotation angle+2π*third setting value may be selected, wherein the third setting value is a non-positive number.

[0214] In summary, different methods can be used to determine the candidate phase rotation angle, which can improve the flexibility and applicability of the method.

[0215] Step S503: Obtain the SNR of the frequency domain signal corresponding to the time domain signal on the pilot symbol at each candidate phase rotation angle.

[0216] For the explanation of step S503, please refer to the relevant description in any embodiment of the present application, and will not be repeated here.

[0217] Step S504: determining a target phase rotation angle from each candidate phase rotation angle according to the SNR of the frequency domain signal at each candidate phase rotation angle.

[0218] In the embodiment of the present application, the target phase rotation angle may be determined from the candidate phase rotation angles according to the SNR of the frequency domain signal corresponding to the pilot symbol at each candidate phase rotation angle.

[0219] In any one of the embodiments of the present application, only the frequency domain signal of a pilot symbol can be selected to calculate the SNR. In this case, the target phase rotation angle can be determined, for example, based on the SNR of the frequency domain signal of the selected pilot symbol at each candidate phase rotation angle, from each candidate phase rotation angle, the candidate phase rotation angle with the largest SNR can be determined and used as the target phase rotation angle.

[0220] In any embodiment of the present application, frequency domain signals of multiple pilot symbols may be selected to calculate SNR. In this case, the target phase rotation angle may be determined, for example, as follows:

[0221] 1. For any candidate phase rotation angle, the average SNR of the frequency domain signal corresponding to the time domain signal on multiple pilot symbols under any candidate phase rotation angle is used as the target SNR of any candidate phase rotation angle.

[0222] In an embodiment of the present application, for any candidate phase rotation angle, the average SNR of the frequency domain signal corresponding to the time domain signal on multiple pilot symbols at the candidate phase rotation angle can be calculated, and the average is used as the target SNR of the candidate phase rotation angle.

[0223] 2. The candidate phase rotation angle with the largest target SNR is used as the target phase rotation angle.

[0224] In summary, the target phase rotation angle can be determined in different ways, thereby improving the flexibility and applicability of the method.

[0225] Step S505: determine a target frequency offset according to a target phase rotation angle.

[0226] In the embodiment of the present application, the target frequency offset may be calculated according to the target phase rotation angle, wherein the calculation method of the target frequency offset is similar to the calculation method of the candidate frequency offset, and will not be described in detail here.

[0227] Step S506: Perform frequency offset compensation on the uplink signal according to the target frequency offset.

[0228] The frequency offset compensation method for the uplink signal in the embodiment of the present application can realize the calculation of the frequency offset based on the optimal phase rotation angle of SNR, and can improve the accuracy of the frequency offset calculation.

[0229] In any embodiment of the present application, the present application proposes a method for expanding the frequency offset estimation range in a scenario where the terminal device moves at high speed, so as to solve the frequency offset estimation problem when the moving speed of the terminal device exceeds the range of multiple pilot frequency discrimination columns. This method can be applied to single cell scenarios and scenarios where multiple cells are merged.

[0230] The present application utilizes the characteristic that the SNR of channel estimation decreases when the frequency offset estimation exceeds the demodulation range, and combines it with the law of phase reversal after the frequency offset exceeds the demodulation range. During the channel estimation process, ICI is eliminated for the frequency offset estimation results in different intervals respectively, and then the SNR after ICI elimination is calculated, and the frequency offset estimation result with the best SNR condition is taken as the final frequency offset estimation result.

[0231] It is understandable that in the scenario where the terminal device moves at high speed, as the frequency offset increases, the inter-carrier interference (ICI) between frequency domain samples or REs on different subcarriers in the same OFDM symbol becomes larger and larger. If it is not processed, the SNR of the channel estimation will be seriously reduced. Similarly, if the estimated frequency offset exceeds the frequency discrimination range, then using the wrong frequency offset value for ICI elimination will also significantly reduce the SNR of the channel estimation.

[0232] The following first explains the flipping rule when the frequency deviation exceeds the frequency discrimination range:

[0233] Assuming that the frequency deviation direction is positive, as the frequency deviation increases, the corresponding phase rotation angle increases continuously. When the phase rotation angle is greater than π, the estimated phase rotation angle flips, such as Figure 6 As shown by the triangle in , the estimated phase rotation angle is negative at this time.

[0234] In order to find the phase reversal law, the unit circle can be expanded as follows: Figure 7 The straight line shown in the figure, triangle 1 is the actual corresponding real phase rotation angle Δθ real , triangle 2 is the estimated phase rotation angle Δθ after flipping est .

[0235] Depend on Figure 7 It can be seen that when Δθ real If Δθ does not exceed 2π, real =Δθ est +2π, similarly, for the case where the frequency deviation is negative, Δθ real =Δθ est -2π.

[0236] Due to the large frequency offset, ICI will be introduced between the frequency domain samples, which will reduce the SNR of the channel estimation. According to formulas (3)-(9), when there is a large frequency offset, the SNR of the channel estimation will be affected by ICI interference and will be significantly reduced. Therefore, in the scenario where the terminal device moves at high speed, the channel estimation result needs to be ICI eliminated. If the frequency offset used for ICI elimination is incorrect, the SNR of the channel estimation will also be significantly reduced.

[0237] In this application, the maximum phase rotation angle is 2π as an example. est In the channel estimation part, according to the actual application scenario, try Δθ est +i*2π(where i=-n 1 ,-n 1 +1,…,0,…,n 1 -1,n 1 , n 1 Different values ​​can be set according to different application scenarios. For example, n can be determined according to the frequency deviation range tolerated by the access network equipment. 1 The specific value of ), the corresponding frequency offset value is ICI eliminated, and then the SNR value of the channel estimation is calculated and compared with 2n 1 +1 SNR value, select the correct frequency deviation interval according to the SNR (for example, you can select according to the interval corresponding to the maximum SNR value).

[0238] In combination with the first embodiment, the method is exemplified below in a scenario where two cells (cell 0 and cell 1) are merged.

[0239] The carrier frequency of the 5G NR access network equipment is configured to be 2.1G, the subcarrier spacing is 15kHz, the transmission duration of a time slot is 1ms, the terminal equipment schedules 50RB (Resource Block), the frequency deviation is 2.1GHz, and the double-column pilot configuration (for example, the pilot symbols are symbol 2 and symbol 11). When the terminal equipment is located on the high-speed rail, the terminal equipment is configured to the cell merging mode. When the access network equipment actually receives the uplink signal, it merges and processes the signals received by the antennas of cell 0 and cell 1. Cell 0 and cell 1 are each configured with 2 antennas. The relative relationship between them and the high-speed rail is as follows: Figure 8 shown.

[0240] Assuming that the high-speed rail is moving at a speed of 250km / h, the speed for cell 0 is 250km / h, and the speed for cell 1 is -250km / h. Converted into frequency deviation, and considering the fact that the center frequency of the terminal device follows the adjustment of the access network equipment, the frequency deviation (where f cis the central frequency of the access network device, v is the moving speed of the terminal device (m / s), and c represents the speed of light). The frequency deviation of cell 0 is calculated to be 972 Hz. Similarly, the frequency deviation of cell 1 is -972 Hz.

[0241] In the related art, when two columns of pilot signals are configured, due to the limitation of the estimated offset range [-π,π], the frequency offset estimation range supported by the theory is: -π<2*π*Δf*(l 1 -l 0 )Δt≤π,

[0242] In the current configuration, one time slot has 14 OFDM symbols, the transmission time is 1ms, and the time interval between two adjacent OFDM symbols is Therefore, we have:

[0243] That is, -778Hz<Δf≤778Hz.

[0244] Therefore, the current frequency offset configuration exceeds the frequency offset estimation range for each cell.

[0245] In this application, the above problems can be solved by the following steps:

[0246] Step 1: Both cells perform rough frequency offset estimation to obtain the phase rotation angle Δθ est,0 and Δθ est,1 .

[0247] Step 2: Confirm the search space.

[0248] The maximum speed that the system needs to support is 350km / h. The formula is used for calculation. The frequency deviation range to be supported is [-1361Hz, 1361Hz], so the phase interval is between [-2π, 2π]. The schematic diagram is as follows Fig. 9 shown.

[0249] For the forward movement speed ( Fig. 9 In the triangle 3), if a phase flip occurs, a negative phase rotation angle will be estimated. For the reverse movement speed ( Fig. 9 In triangle 4), if a phase flip occurs, a positive phase rotation angle will be estimated. Using the above rules, for each roughly estimated phase rotation angle Δθ est,k (k represents the cell index, which can be 0 or 1), search space Δθ est,k The value of i in +i*2π is as follows:

[0250] If Δθ est,k >0, then i=0,-1;

[0251] If Δθ est,k ≤0, then i=0,1.

[0252] Step 3: Perform ICI elimination for each frequency offset.

[0253] The two cells use the frequency offset corresponding to the phase rotation angle in the search space to estimate the channel result H according to the rule in step 2. k (referred to as the first channel estimation result in this application, where k represents the cell index) ICI elimination is performed, and the channel estimation result after ICI elimination is obtained as H k,i (Recorded as the second channel estimation result in this application, where k represents the cell index and i represents the search space).

[0254] Step 4: Calculate the SNR corresponding to each frequency offset.

[0255] That is, calculate H k,i The corresponding SNR is denoted as SNR k,i .

[0256] Step 5: Select the correct frequency offset interval according to the SNR.

[0257] For each cell, find the search space index i with the maximum SNR k , according to the search space index i k For Δθ est,k Make corresponding adjustments to obtain the final phase estimation result Δθ′ for each cell est,k =Δθ est,k +i k *2π.

[0258] It should be noted that the above only uses the search interval corresponding to the maximum SNR as the final phase interval as an example, but in actual applications, different principles can be used to determine the phase interval.

[0259] As an example, Fig.10 The left side of the figure is a demodulated constellation diagram obtained by using the solution provided by the present application. Fig.10 The right side of the figure is the demodulated constellation diagram obtained by using the original solution in the related art. It can be seen that the solution provided by this application has a huge improvement in performance.

[0260] In summary, the present application can solve the problem of frequency offset estimation when the pilot configuration does not meet the frequency offset estimation range. Performing a phase interval determination operation before channel equalization can solve the problem of over-frequency offset estimation when multiple cells are merged and the frequency offset ranges of different cells are different.

[0261] 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 (Global System of Mobile communication, referred to as GSM) system, code division multiple access (Code Division Multiple Access, referred to as CDMA) system, wideband code division multiple access (Wideband Code Division Multiple Access, referred to as WCDMA) general packet radio service (General Packet Radio Service, referred to as GPRS) system, long term evolution (long term evolution, referred to as LTE) system, LTE frequency division duplex (Frequency Division Duplex, referred to as FDD) system, LTE time division duplex (time division duplex, referred to as TDD) system, advanced long term evolution (Long Term Evolution Advanced, referred to as LTE-A) system, Universal Mobile Telecommunication System (Universal Mobile Telecommunication System, referred to as UMTS), Worldwide interoperability for Microwave Access (Worldwide interoperability for Microwave Access, referred to as WiMAX) system, 5G new air interface (NewRadio, referred to as NR) system, etc. These various systems include terminals and network equipment. The system may also include a core network part, such as an evolved packet system (EPS), a 5G system (5GS), etc.

[0262] In order to implement the above embodiments, the present application also provides an access network device.

[0263] Fig.11 It is a structural diagram of an access network device provided according to an embodiment of the present application.

[0264] like Fig.11 As shown, the access network device may include a transceiver 1100, a processor 1110, and a memory 1120, wherein:

[0265] The transceiver 1100 is used to receive and send data under the control of the processor 1110 .

[0266] Among them, Fig.11In the embodiment, the bus architecture may include any number of interconnected buses and bridges, specifically one or more processors represented by processor 1110 and various circuits of memory represented by memory 1120 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 1100 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 1110 is responsible for managing the bus architecture and general processing, and the memory 1120 may store data used by the processor 1110 when performing operations.

[0267] The processor 1110 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.

[0268] The processor 1110 calls a computer program stored in a memory and performs the following operations: receiving an uplink signal sent by a target terminal and obtaining an initial phase rotation angle corresponding to the uplink signal; wherein the uplink signal includes a time domain signal on at least one pilot symbol; determining at least one candidate phase shift angle based on the initial phase rotation angle and a set maximum phase rotation angle; obtaining a signal-to-noise ratio (SNR) of a frequency domain signal corresponding to the time domain signal on the pilot symbol at each candidate phase rotation angle; determining a target frequency deviation based on the SNR of the frequency domain signal at each candidate phase rotation angle, and performing frequency deviation compensation on the uplink signal based on the target frequency deviation.

[0269] As a possible implementation method, the number of pilot symbols is multiple, and the processor 1110 executes to obtain the initial phase rotation angle corresponding to the uplink signal, specifically: performing fast Fourier transform FFT on the time domain signals on the multiple pilot symbols respectively to obtain multiple frequency domain signals; wherein the frequency domain signal includes frequency domain sampling points corresponding to multiple subcarriers; according to the frequency domain sampling points of the same subcarrier in the multiple frequency domain signals, determining the intermediate value corresponding to the same subcarrier; and determining the initial phase rotation angle according to the average of the intermediate values ​​of the multiple subcarriers.

[0270] As a possible implementation method, the processor 1110 executes the signal-to-noise ratio SNR of the frequency domain signal corresponding to the time domain signal on the pilot symbol at each candidate phase rotation angle, specifically: obtaining the first channel estimation result of the frequency domain signal at each candidate phase rotation angle; performing inter-carrier interference (ICI) elimination processing on the first channel estimation result at each candidate phase rotation angle, to obtain the second channel estimation result at each candidate phase rotation angle; and determining the SNR of the frequency domain signal at each candidate phase rotation angle according to the second channel estimation result at each candidate phase rotation angle.

[0271] As a possible implementation method, the processor 1110 executes to obtain the first channel estimation result of the frequency domain signal at each candidate phase rotation angle, specifically: according to any candidate phase rotation angle, determine the candidate frequency offset; based on the candidate frequency offset, perform channel estimation on the frequency domain signal to obtain the first channel estimation result of the frequency domain signal at any candidate phase rotation angle.

[0272] As a possible implementation method, the number of pilot symbols is multiple, and the processor 1110 determines the candidate frequency offset based on any candidate phase rotation angle, specifically: obtaining the index difference between the position indexes of multiple pilot symbols; obtaining the transmission duration of the pilot symbols; taking the product of the index difference and the transmission duration as the first intermediate coefficient; and determining the candidate frequency offset based on the ratio of any candidate phase rotation angle to the first intermediate coefficient.

[0273] As a possible implementation method, the processor 1110 determines the target frequency deviation based on the SNR of the frequency domain signal at each candidate phase rotation angle, specifically: determines the target phase rotation angle from each candidate phase rotation angle based on the SNR of the frequency domain signal at each candidate phase rotation angle; determines the target frequency deviation based on the target phase rotation angle.

[0274] As a possible implementation method, the number of pilot symbols is one, and the processor 1110 determines the target phase rotation angle from each candidate phase rotation angle based on the SNR of the frequency domain signal at each candidate phase rotation angle, specifically: taking the candidate phase rotation angle with the largest SNR as the target phase rotation angle.

[0275] As a possible implementation method, the number of pilot symbols is multiple, and the processor 1110 determines the target phase rotation angle from each candidate phase rotation angle based on the SNR of the frequency domain signal at each candidate phase rotation angle. Specifically, for any candidate phase rotation angle, the average of the SNRs of the frequency domain signal corresponding to the time domain signals on multiple pilot symbols at any candidate phase rotation angle is used as the target SNR of any candidate phase rotation angle; and the candidate phase rotation angle with the largest target SNR is used as the target phase rotation angle.

[0276] As a possible implementation method, the processor 1110 determines at least one candidate phase conversion angle based on the initial phase rotation angle and the set maximum phase rotation angle, specifically: obtaining at least one first setting value; wherein the first setting value is an integer; for any first setting value, taking the product of any first setting value and the maximum phase rotation angle as the second intermediate coefficient; taking the sum of the second intermediate coefficient and the initial phase rotation angle as the candidate phase rotation angle.

[0277] As a possible implementation method, the processor 1110 determines at least one candidate phase conversion angle based on the initial phase rotation angle and the set maximum phase rotation angle, specifically: determines whether the initial phase rotation angle is a positive number; if the initial phase rotation angle is not a positive number, obtains at least one second set value; wherein the second set value is a natural number; for any second set value, takes the product of any second set value and the maximum phase rotation angle as a third intermediate coefficient; and takes the sum of the third intermediate coefficient and the initial phase rotation angle as a candidate phase rotation angle.

[0278] As a possible implementation method, the processor 1110 determines at least one candidate phase conversion angle based on the initial phase rotation angle and the set maximum phase rotation angle, specifically: if the initial phase rotation angle is a positive number, obtain at least one third set value; wherein the third set value is a negative number of the second set value; for any third set value, the product of any third set value and the maximum phase rotation angle is used as a fourth intermediate coefficient; and the sum of the fourth intermediate coefficient and the initial phase rotation angle is used as a candidate phase rotation angle.

[0279] It should be noted that the access network device provided in the embodiment of the present application can achieve the above Figures 1 to 5 All the method steps implemented in the method embodiment can achieve the same technical effect, and the parts and beneficial effects of this embodiment that are the same as those in the method embodiment will not be described in detail here.

[0280] With the above Figures 1 to 5 Corresponding to the frequency offset compensation method for uplink signals provided in the embodiment, the present application also provides a frequency offset compensation device for uplink signals. Figures 1 to 5 The frequency offset compensation method for the uplink signal provided in the embodiment corresponds to the frequency offset compensation method for the uplink signal, so the implementation method of the frequency offset compensation method for the uplink signal is also applicable to the frequency offset compensation device for the uplink signal provided in the embodiment of the present application, and will not be described in detail in the embodiment of the present application.

[0281] In order to implement the above embodiment, the present application also proposes a frequency offset compensation device for an uplink signal.

[0282] Fig.12It is a structural schematic diagram of a frequency offset compensation device for an uplink signal provided in an embodiment of the present application.

[0283] like Fig.12 As shown, the frequency offset compensation device 1200 for uplink signals can be applied to access network equipment, and includes: a first processing unit 1210 , a determining unit 1220 , an acquiring unit 1230 and a second processing unit 1240 .

[0284] The first processing unit 1210 is configured to receive an uplink signal sent by a target terminal and obtain an initial phase rotation angle corresponding to the uplink signal; wherein the uplink signal includes a time domain signal on at least one pilot symbol.

[0285] The determining unit 1220 is configured to determine at least one candidate phase rotation angle according to the initial phase rotation angle and the set maximum phase rotation angle.

[0286] The acquisition unit 1230 is configured to acquire a signal-to-noise ratio (SNR) of a frequency domain signal corresponding to a time domain signal on the pilot symbol at each candidate phase rotation angle.

[0287] The second processing unit 1240 is configured to determine a target frequency offset according to the SNR of the frequency domain signal at each candidate phase rotation angle, and perform frequency offset compensation on the uplink signal according to the target frequency offset.

[0288] As a possible implementation method, the number of pilot symbols is multiple, and the first processing unit 1210 is specifically used to: perform FFT on the time domain signals on the multiple pilot symbols respectively to obtain multiple frequency domain signals; wherein the frequency domain signal includes frequency domain samples corresponding to multiple subcarriers; determine the intermediate value corresponding to the same subcarrier according to the frequency domain samples of the same subcarrier in the multiple frequency domain signals; determine the initial phase rotation angle according to the average of the intermediate values ​​of the multiple subcarriers.

[0289] As a possible implementation method, the acquisition unit 1230 is specifically used to: obtain a first channel estimation result of the frequency domain signal at each candidate phase rotation angle; perform inter-carrier interference (ICI) elimination processing on the first channel estimation result at each candidate phase rotation angle to obtain a second channel estimation result at each candidate phase rotation angle; and determine the SNR of the frequency domain signal at each candidate phase rotation angle based on the second channel estimation result at each candidate phase rotation angle.

[0290] As a possible implementation method, the acquisition unit 1230 is specifically used to: determine a candidate frequency offset based on any candidate phase rotation angle; perform channel estimation on the frequency domain signal based on the candidate frequency offset to obtain a first channel estimation result of the frequency domain signal under any candidate phase rotation angle.

[0291] As a possible implementation method, the number of pilot symbols is multiple, and the acquisition unit 1230 is specifically used to: obtain the index difference between the position indexes of multiple pilot symbols; obtain the transmission duration of the pilot symbols; use the product of the index difference and the transmission duration as the first intermediate coefficient; and determine the candidate frequency offset based on the ratio of any candidate phase rotation angle to the first intermediate coefficient.

[0292] As a possible implementation, the second processing unit 1240 is specifically configured to: determine a target phase rotation angle from each candidate phase rotation angle according to the SNR of the frequency domain signal at each candidate phase rotation angle; and determine a target frequency offset according to the target phase rotation angle.

[0293] As a possible implementation manner, the number of pilot symbols is one, and the second processing unit 1240 is specifically configured to: use the candidate phase rotation angle with the maximum SNR as the target phase rotation angle.

[0294] As a possible implementation method, the number of pilot symbols is multiple, and the second processing unit 1240 is specifically used to: for any candidate phase rotation angle, use the average of the SNRs of the frequency domain signals corresponding to the time domain signals on multiple pilot symbols at any candidate phase rotation angle as the target SNR of any candidate phase rotation angle; use the candidate phase rotation angle with the largest target SNR as the target phase rotation angle.

[0295] As a possible implementation method, determination unit 1220 is specifically used to: obtain at least one first setting value; wherein the first setting value is an integer; for any first setting value, use the product of any first setting value and the maximum phase rotation angle as the second intermediate coefficient; and use the sum of the second intermediate coefficient and the initial phase rotation angle as the candidate phase rotation angle.

[0296] As a possible implementation method, the determination unit 1220 is specifically used to: determine whether the initial phase rotation angle is a positive number; if the initial phase rotation angle is not a positive number, obtain at least one second setting value; wherein the second setting value is a natural number; for any second setting value, use the product of any second setting value and the maximum phase rotation angle as a third intermediate coefficient; and use the sum of the third intermediate coefficient and the initial phase rotation angle as a candidate phase rotation angle.

[0297] As a possible implementation method, the determination unit 1220 is also used to: if the initial phase rotation angle is a positive number, obtain at least one third setting value; wherein the third setting value is a negative number of the second setting value; for any third setting value, use the product of any third setting value and the maximum phase rotation angle as a fourth intermediate coefficient; and use the sum of the fourth intermediate coefficient and the initial phase rotation angle as a candidate phase rotation angle.

[0298] It should be noted that the frequency offset compensation device for uplink signals provided in the embodiment of the present application can achieve the above Figures 1 to 5 All the method steps implemented in the method embodiment can achieve the same technical effect, and the parts and beneficial effects of this embodiment that are the same as those in the method embodiment will not be described in detail here.

[0299] 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.

[0300] 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 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, a server, or a network side device, etc.) or a processor (processor) to perform all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory, ROM), random access memory (Random Access Memory, referred to as RAM), disk or optical disk and other media that can store program codes.

[0301] It should be noted here that the above-mentioned device provided in the embodiment of 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 those in the method embodiment will not be described in detail here.

[0302] On the other hand, an embodiment of the present application further provides a processor-readable storage medium, the processor-readable storage medium storing a computer program, the computer program is used to enable the processor to execute the present application Figures 1 to 5 The method shown in the embodiment.

[0303] Among them, the above-mentioned processor-readable storage medium can be any available medium or data storage device that can be accessed by the processor, including but not limited to magnetic storage (such as floppy disks, hard disks, magnetic tapes, magneto-optical disks (MO)), optical storage (such as CD, DVD, BD, HVD, etc.), and semiconductor storage (such as ROM, EPROM, EEPROM, non-volatile memory (NANDFLASH), solid-state drive (SSD)), etc.

[0304] 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.

[0305] 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.

[0306] 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.

[0307] 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.

[0308] 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. A method for compensating frequency deviation of an uplink signal, characterized in that: Applied to access network equipment, the method comprises: Receive an uplink signal sent by a target terminal, and obtain an initial phase rotation angle corresponding to the uplink signal; wherein the uplink signal includes a time domain signal on at least one pilot symbol; Determine at least one candidate phase rotation angle according to the initial phase rotation angle and the set maximum phase rotation angle; Acquire a signal-to-noise ratio (SNR) of a frequency domain signal corresponding to the time domain signal on the pilot symbol at each candidate phase rotation angle; A target frequency offset is determined according to the SNR of the frequency domain signal at each of the candidate phase rotation angles, and frequency offset compensation is performed on the uplink signal according to the target frequency offset.

2. The method according to claim 1, characterized in that The number of the pilot symbols is multiple, and the obtaining of the initial phase rotation angle corresponding to the uplink signal includes: Performing fast Fourier transform (FFT) on the time domain signals on the multiple pilot symbols respectively to obtain multiple frequency domain signals; wherein the frequency domain signals include frequency domain sample points corresponding to multiple subcarriers; Determine, according to the frequency domain samples of the same subcarrier in the multiple frequency domain signals, an intermediate value corresponding to the same subcarrier; The initial phase rotation angle is determined according to an average of intermediate values ​​of the multiple subcarriers.

3. The method according to claim 1, characterized in that The obtaining of a signal-to-noise ratio (SNR) of a frequency domain signal corresponding to a time domain signal on the pilot symbol at each candidate phase rotation angle comprises: Obtaining a first channel estimation result of the frequency domain signal at each of the candidate phase rotation angles; Performing inter-carrier interference (ICI) elimination processing on the first channel estimation results under each of the candidate phase rotation angles to obtain second channel estimation results under each of the candidate phase rotation angles; The SNR of the frequency domain signal at each of the candidate phase rotation angles is determined according to the second channel estimation result at each of the candidate phase rotation angles.

4. The method according to claim 3, characterized in that The obtaining a first channel estimation result of the frequency domain signal at each candidate phase rotation angle comprises: Determining a candidate frequency offset according to any candidate phase rotation angle; Based on the candidate frequency offset, channel estimation is performed on the frequency domain signal to obtain a first channel estimation result of the frequency domain signal under any of the candidate phase rotation angles.

5. The method according to claim 4, characterized in that The number of the pilot symbols is multiple, and the determining the candidate frequency offset according to any candidate phase rotation angle includes: Obtaining an index difference between position indexes of a plurality of the pilot symbols; Obtaining a transmission duration of the pilot symbol; Taking the product of the index difference and the transmission duration as a first intermediate coefficient; The candidate frequency offset is determined according to a ratio of any candidate phase rotation angle to the first intermediate coefficient.

6. The method according to any one of claims 1 to 5, characterized in that The determining the target frequency offset according to the SNR of the frequency domain signal at each of the candidate phase rotation angles includes: Determining a target phase rotation angle from each of the candidate phase rotation angles according to the SNR of the frequency domain signal at each of the candidate phase rotation angles; The target frequency offset is determined according to the target phase rotation angle.

7. The method according to claim 6, characterized in that The number of the pilot symbol is one, and determining the target phase rotation angle from each of the candidate phase rotation angles according to the SNR of the frequency domain signal at each of the candidate phase rotation angles includes: The candidate phase rotation angle with the maximum SNR is used as the target phase rotation angle.

8. The method according to claim 6, characterized in that The number of the pilot symbols is multiple, and determining the target phase rotation angle from each of the candidate phase rotation angles according to the SNR of the frequency domain signal at each of the candidate phase rotation angles includes: For any candidate phase rotation angle, taking an average of SNRs of frequency domain signals corresponding to time domain signals on a plurality of pilot symbols at the any candidate phase rotation angle as a target SNR for the any candidate phase rotation angle; The candidate phase rotation angle with the maximum target SNR is used as the target phase rotation angle.

9. The method according to any one of claims 1 to 5, characterized in that The step of determining at least one candidate phase shift angle according to the initial phase rotation angle and the set maximum phase rotation angle comprises: Obtain at least one first setting value; wherein the first setting value is an integer; For any first setting value, taking the product of the first setting value and the maximum phase rotation angle as the second intermediate coefficient; The sum of the second intermediate coefficient and the initial phase rotation angle is used as the candidate phase rotation angle.

10. The method according to any one of claims 1 to 5, characterized in that The step of determining at least one candidate phase shift angle according to the initial phase rotation angle and the set maximum phase rotation angle comprises: Determining whether the initial phase rotation angle is a positive number; If the initial phase rotation angle is not a positive number, obtaining at least one second setting value; wherein the second setting value is a natural number; For any second setting value, taking the product of the any second setting value and the maximum phase rotation angle as a third intermediate coefficient; The sum of the third intermediate coefficient and the initial phase rotation angle is used as the candidate phase rotation angle.

11. The method according to claim 10, characterized in that The determining of at least one candidate phase shift angle according to the initial phase rotation angle and the set maximum phase rotation angle further includes: If the initial phase rotation angle is a positive number, obtaining at least one third setting value; wherein the third setting value is a negative number of the second setting value; For any third setting value, taking the product of the any third setting value and the maximum phase rotation angle as a fourth intermediate coefficient; The sum of the fourth intermediate coefficient and the initial phase rotation angle is used as the candidate phase rotation angle.

12. An access network device, characterized in that: Including memory, transceiver, processor; A memory for storing a computer program; a transceiver for transmitting and receiving data under the control of the processor; and a processor for reading the computer program in the memory and performing the following operations: Receive an uplink signal sent by a target terminal, and obtain an initial phase rotation angle corresponding to the uplink signal; wherein the uplink signal includes a time domain signal on at least one pilot symbol; Determining at least one candidate phase shift angle according to the initial phase rotation angle and the set maximum phase rotation angle; Acquire a signal-to-noise ratio (SNR) of a frequency domain signal corresponding to the time domain signal on the pilot symbol at each candidate phase rotation angle; A target frequency offset is determined according to the SNR of the frequency domain signal at each of the candidate phase rotation angles, and frequency offset compensation is performed on the uplink signal according to the target frequency offset.

13. The access network device according to claim 12, characterized in that: The number of the pilot symbols is multiple, and the processor executes the acquisition of the initial phase rotation angle corresponding to the uplink signal, specifically: Performing fast Fourier transform (FFT) on the time domain signals on the multiple pilot symbols respectively to obtain multiple frequency domain signals; wherein the frequency domain signals include frequency domain sample points corresponding to multiple subcarriers; Determine, according to the frequency domain samples of the same subcarrier in the multiple frequency domain signals, an intermediate value corresponding to the same subcarrier; The initial phase rotation angle is determined according to an average of intermediate values ​​of the multiple subcarriers.

14. The access network device according to claim 12, characterized in that: The processor executes the acquisition of the signal-to-noise ratio SNR of the frequency domain signal corresponding to the time domain signal on the pilot symbol at each candidate phase rotation angle, specifically: Obtaining a first channel estimation result of the frequency domain signal at each of the candidate phase rotation angles; Performing inter-carrier interference (ICI) elimination processing on the first channel estimation results under each of the candidate phase rotation angles to obtain second channel estimation results under each of the candidate phase rotation angles; The SNR of the frequency domain signal at each of the candidate phase rotation angles is determined according to the second channel estimation result at each of the candidate phase rotation angles.

15. The access network device according to claim 14, characterized in that: The processor executes acquiring a first channel estimation result of the frequency domain signal at each candidate phase rotation angle, specifically: Determining a candidate frequency offset according to any candidate phase rotation angle; Based on the candidate frequency offset, channel estimation is performed on the frequency domain signal to obtain a first channel estimation result of the frequency domain signal under any of the candidate phase rotation angles.

16. The access network device according to claim 15, characterized in that: The number of pilot symbols is multiple, and the processor determines the candidate frequency offset according to any candidate phase rotation angle, specifically: Obtaining an index difference between position indexes of a plurality of the pilot symbols; Obtaining a transmission duration of the pilot symbol; Taking the product of the index difference and the transmission duration as a first intermediate coefficient; The candidate frequency offset is determined according to a ratio of any candidate phase rotation angle to the first intermediate coefficient.

17. The access network device according to any one of claims 12 to 16, characterized in that: The processor determines the target frequency offset according to the SNR of the frequency domain signal at each of the candidate phase rotation angles, specifically: Determining a target phase rotation angle from each of the candidate phase rotation angles according to the SNR of the frequency domain signal at each of the candidate phase rotation angles; The target frequency offset is determined according to the target phase rotation angle.

18. The access network device according to claim 17, characterized in that: The number of the pilot symbol is one, and the processor determines a target phase rotation angle from each of the candidate phase rotation angles according to the SNR of the frequency domain signal at each of the candidate phase rotation angles, specifically: The candidate phase rotation angle with the maximum SNR is used as the target phase rotation angle.

19. The access network device according to claim 17, characterized in that: The number of the pilot symbols is multiple, and the processor determines the target phase rotation angle from each of the candidate phase rotation angles according to the SNR of the frequency domain signal at each of the candidate phase rotation angles, specifically: For any candidate phase rotation angle, taking an average of SNRs of frequency domain signals corresponding to time domain signals on a plurality of pilot symbols at the any candidate phase rotation angle as a target SNR for the any candidate phase rotation angle; The candidate phase rotation angle with the maximum target SNR is used as the target phase rotation angle.

20. The access network device according to any one of claims 12 to 16, characterized in that: The processor determines at least one candidate phase shift angle according to the initial phase rotation angle and the set maximum phase rotation angle, specifically: Obtain at least one first setting value; wherein the first setting value is an integer; For any first setting value, taking the product of the first setting value and the maximum phase rotation angle as the second intermediate coefficient; The sum of the second intermediate coefficient and the initial phase rotation angle is used as the candidate phase rotation angle.

21. The access network device according to any one of claims 12 to 16, characterized in that: The processor determines at least one candidate phase shift angle according to the initial phase rotation angle and the set maximum phase rotation angle, specifically: Determining whether the initial phase rotation angle is a positive number; If the initial phase rotation angle is not a positive number, obtaining at least one second setting value; wherein the second setting value is a natural number; For any second setting value, taking the product of the any second setting value and the maximum phase rotation angle as a third intermediate coefficient; The sum of the third intermediate coefficient and the initial phase rotation angle is used as the candidate phase rotation angle.

22. The access network device according to claim 21, characterized in that: The processor determines at least one candidate phase shift angle according to the initial phase rotation angle and the set maximum phase rotation angle, specifically: If the initial phase rotation angle is a positive number, obtaining at least one third setting value; wherein the third setting value is a negative number of the second setting value; For any third setting value, taking the product of the any third setting value and the maximum phase rotation angle as a fourth intermediate coefficient; The sum of the fourth intermediate coefficient and the initial phase rotation angle is used as the candidate phase rotation angle.

23. A frequency deviation compensation device for an uplink signal, characterized in that: Applied to access network equipment, the device comprises: A first processing unit, configured to receive an uplink signal sent by a target terminal and obtain an initial phase rotation angle corresponding to the uplink signal; wherein the uplink signal includes a time domain signal on at least one pilot symbol; a determining unit, configured to determine at least one candidate phase rotation angle according to the initial phase rotation angle and a set maximum phase rotation angle; An acquisition unit, configured to acquire a signal-to-noise ratio (SNR) of a frequency domain signal corresponding to a time domain signal on the pilot symbol at each candidate phase rotation angle; The second processing unit is used to determine a target frequency offset according to the SNR of the frequency domain signal at each of the candidate phase rotation angles, and perform frequency offset compensation on the uplink signal according to the target frequency offset.

24. A processor-readable storage medium, characterized in that: The processor-readable storage medium stores a computer program, and the computer program is used to cause the processor to execute the method according to any one of claims 1 to 11.

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