Pilot signal generation method, pilot signal reception method, apparatus, device, medium, and product

Abstract

This disclosure provides a pilot signal generation method, a pilot signal receiving method, an apparatus, a device, a medium, and a product. In this method, the transmitting end acquires a first signal with a first characteristic in the frequency domain and a second signal with a second characteristic in the time domain, and generates a pilot signal based on the first and second signals. This combination of signals with different characteristics results in a pilot signal that possesses both significant frequency domain characteristics, facilitating frequency offset estimation, and good time domain characteristics, facilitating time synchronization. Conversely, the receiving end acquires a received signal containing the pilot signal and performs time-frequency correction using the first and second characteristics of the pilot signal, thereby achieving time-frequency synchronization. This satisfies the requirement to simultaneously estimate rapidly changing time and frequency offsets, effectively solving problems such as signal distortion and decoding errors caused by time-frequency asynchrony, and improving the synchronization efficiency and data transmission quality of the communication system.

Description

Technical Field

[0001] This disclosure relates primarily to the field of communication technology, and in particular to a pilot signal generation method, a pilot signal receiving method, an apparatus, a device, a medium, and a product. Background Technology

[0002] In modern communication systems, pilot signals generally refer to signals whose content is known in advance at the receiver. They assist the receiver in achieving channel estimation and time-frequency synchronization. Time-frequency synchronization technologies such as carrier synchronization and timing synchronization are key technologies for digital receivers, and synchronization performance directly affects whether data can be correctly demodulated.

[0003] However, in existing time-frequency synchronization technologies, time offset correction and frequency offset correction usually rely on different algorithms and pilot signal characteristics. For example, time synchronization relies on pilot signals with autocorrelation characteristics, while frequency synchronization relies on pilot signals with phase characteristics. This results in existing pilot signals being able to achieve timing synchronization or carrier synchronization alone, but not simultaneously time-frequency synchronization. It is difficult to meet the requirements of simultaneously estimating rapidly changing time and frequency offsets, and performs poorly in high-dynamic scenarios such as large frequency and time offsets. This can easily lead to time / frequency synchronization failure, increase frequency estimation errors, and reduce channel estimation efficiency. Summary of the Invention

[0004] Providing a mechanism to alleviate, reduce or eliminate at least one of the above problems would be beneficial.

[0005] In a first aspect, this disclosure provides a pilot signal generation method applied at a transmitting end, the method comprising:

[0006] Acquire a first signal and a second signal, wherein the first signal has a first characteristic in the frequency domain and the second signal has a second characteristic in the time domain;

[0007] A pilot signal is generated based on the first signal and the second signal.

[0008] In a second aspect, this disclosure provides a pilot signal receiving method, applied at a receiving end, the method comprising:

[0009] Acquire a received signal, the received signal including a pilot signal;

[0010] Based on the first and second characteristics of the pilot signal, the received signal is time-frequency corrected to achieve time-frequency synchronization at the receiving end.

[0011] In a third aspect, this disclosure provides a pilot signal generation apparatus for use at a transmitting end, the apparatus comprising:

[0012] An acquisition unit is used to acquire a first signal and a second signal, wherein the first signal has a first characteristic in the frequency domain and the second signal has a second characteristic in the time domain;

[0013] The generation unit is used to generate pilot signals based on the first signal and the second signal.

[0014] Optionally, the first characteristic indicates that the power of the first signal is concentrated at a single frequency.

[0015] Optionally, the second characteristic indicates that the ratio of the main peak to the secondary peak in the autocorrelation result of the second signal is not less than a first threshold.

[0016] Optionally, the generation unit is specifically used for:

[0017] The first signal and the second signal are cross-combined to generate the pilot signal.

[0018] Optionally, the generation unit is specifically used for:

[0019] Based on a preset alternating arrangement order, the first signal and the second signal are cross-combined with a first length to generate a pilot sequence.

[0020] Optionally, after generating the pilot sequence, the generating unit is specifically used for:

[0021] The pilot sequence is modulated to obtain the pilot signal.

[0022] Optionally, the first characteristic characterizing that the power of the first signal is concentrated at a single frequency specifically means that there is an impulse response in the power spectrum of the first signal.

[0023] Optionally, the first signal may include a single-tone signal.

[0024] Optionally, the second signal includes a PN sequence.

[0025] Optionally, the PN sequence is an m-sequence, a ZC sequence, or a Barker code.

[0026] In a fourth aspect, this disclosure provides a pilot signal receiving device for use at a receiving end, the device comprising:

[0027] A receiving unit is used to acquire a received signal, the received signal including a pilot signal;

[0028] The correction unit is used to perform time-frequency correction on the received signal based on the first and second characteristics of the pilot signal, so as to complete the time-frequency synchronization of the receiving end.

[0029] Optionally, the receiving unit is specifically used for:

[0030] The received transmission signal is subjected to windowed sampling processing to obtain the received signal; the peak frequency of the received signal is greater than a preset peak threshold.

[0031] Optionally, the correction unit is specifically used for:

[0032] The received signal is frequency offset corrected based on the frequency offset estimate to obtain a frequency synchronization signal; the frequency offset estimate is determined based on the frequency peak value of the received signal and the center frequency point of the pilot signal.

[0033] Optionally, after obtaining the frequency synchronization signal, the correction unit is specifically used for:

[0034] The received signal is time-biased based on the time-biased estimate; the time-biased estimate is obtained based on the frequency synchronization signal.

[0035] Optionally, the frequency offset estimate characterizes the difference between the received signal and the pilot signal in the frequency domain.

[0036] Optionally, the time offset estimate characterizes the difference between the received signal and the pilot signal in the time domain.

[0037] Optionally, the correction unit is specifically used for:

[0038] Based on the frequency peak value of the received signal, the spectrum synchronization signal is symbol-filtered to obtain a time-domain processed signal.

[0039] The time offset estimate is obtained based on the time-domain correlation function of the time-domain processed signal.

[0040] Optionally, the correction unit is specifically used for:

[0041] Based on the symbol start position of the frequency peak, frequency-domain associated symbols in the frequency synchronization signal are filtered out; the frequency-domain associated symbols and the symbol start position in the frequency synchronization signal are at the same odd or even position.

[0042] Optionally, before filtering out frequency-domain associated symbols in the frequency synchronization signal, the correction unit is specifically used for:

[0043] When the remainder between the index difference of each symbol in the frequency synchronization signal and the preset target value is zero, the corresponding symbol is determined to be the frequency domain associated symbol; the index difference represents the difference between the position index of the corresponding symbol and the starting position of the symbol.

[0044] Optionally, the correction unit is specifically used for:

[0045] The time offset estimate is obtained based on the difference between the peak time of the time-domain correlation function and the reception duration; the peak time is the time point corresponding to the peak value of the time-domain correlation function, and the reception duration is the duration between the peak time and the start time of the received signal.

[0046] In a fifth aspect, this disclosure provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement any of the pilot signal generation methods in the first aspect and / or any of the pilot signal receiving methods in the second aspect.

[0047] In a sixth aspect, this disclosure provides a computer storage medium storing computer program instructions, which are executed by a processor using any of the pilot signal generation methods in the first aspect and / or any of the pilot signal reception methods in the second aspect.

[0048] In a seventh aspect, an embodiment of this disclosure provides a computer program product including computer program instructions, which, when executed by a processor, implement any pilot signal generation method in the first aspect and / or any pilot signal reception method in the second aspect.

[0049] It should be understood that the summary section is not intended to identify key or essential features of the embodiments of this disclosure, nor is it intended to limit the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0050] The accompanying drawings are included to provide a further understanding of this disclosure; they are incorporated into and constitute a part of this disclosure. The drawings illustrate embodiments of this disclosure and, together with this specification, serve to explain the principles of this disclosure. In the drawings:

[0051] Figure 1 This is a schematic diagram of an application scenario provided by an embodiment of this disclosure;

[0052] Figure 2 This is a schematic flowchart of a pilot signal generation method provided in an embodiment of this disclosure;

[0053] Figure 3 This is a schematic diagram of the normalized power spectral density of a single-tone signal provided in an embodiment of this disclosure;

[0054] Figure 4 This is a schematic diagram of the autocorrelation function of a PN sequence provided in an embodiment of this disclosure;

[0055] Figure 5This disclosure provides a process for generating a cross-combination of pilot signals according to an embodiment.

[0056] Figure 6 A schematic flowchart illustrating a pilot signal receiving method provided in an embodiment of this application;

[0057] Figure 7 A schematic diagram illustrating the interaction between a receiver and a transmitter, provided for an embodiment of this application;

[0058] Figure 8 This is a schematic diagram of a pilot signal generation device provided in an embodiment of this application;

[0059] Figure 9 This is a schematic diagram of the structure of a pilot signal receiving device provided in an embodiment of this application;

[0060] Figure 10 This is a schematic diagram of the composition structure of a computer device provided in an embodiment of this application. Detailed Implementation

[0061] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are merely some examples or embodiments of this disclosure. For those skilled in the art, these drawings can be applied to other similar scenarios without creative effort. Unless obvious from the context or otherwise specified, the same reference numerals in the drawings represent the same structures or operations.

[0062] In the following description and claims, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0063] References to "an embodiment," "embodiment," "exemplary embodiment," etc., in this disclosure indicate that the described embodiments may include specific features, structures, or characteristics, but not every embodiment needs to include specific features, structures, or characteristics. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when a specific feature, structure, or characteristic is described in connection with an exemplary embodiment, whether explicitly described or not, those skilled in the art will recognize that such a feature, structure, or characteristic affects its connection to other embodiments.

[0064] As indicated in this disclosure, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" are not specifically singular and may include plural forms, unless the context clearly indicates otherwise. The term "a group of elements" or "a collection of elements" as used herein is intended to include one or more elements. It should also be understood that the terms "comprising," "including," "having," "possessing," "comprise," and / or "including," when used herein, specify the presence of the stated features, elements, and / or components, only indicating the inclusion of explicitly identified steps and elements, which do not constitute an exclusive list. A method or apparatus may also include other steps or elements, and therefore the presence or addition of one or more other features, elements, components, and / or combinations thereof is not excluded.

[0065] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of this disclosure. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0066] In the description of this disclosure, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings and is only for the convenience of describing this disclosure and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this disclosure; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0067] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0068] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, these terms have no special meaning and therefore should not be construed as limiting the scope of protection of this disclosure. Therefore, although the terms "first" and "second," etc., can be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of exemplary embodiments, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element. The term "and / or" as used herein includes any and all combinations of one or more of the listed terms. Furthermore, although the terms used in this disclosure are selected from commonly known and used terms, some terms mentioned in this disclosure may have been selected by the applicant at his or her judgment, and their detailed meanings are explained in the relevant sections of the description herein. Moreover, this disclosure should be understood not only by the actual terms used, but also by the meaning implied by each term.

[0069] The term "terminal device" refers to any terminal device capable of wireless communication. As an example and not a limitation, a terminal device may also be referred to as a communication device, user equipment (UE), subscriber station (SS), portable subscriber station, mobile station (MS), or access terminal (AT). This terminal device may include, but is not limited to, mobile phones, cellular phones, smartphones, Voice over IP (VoIP) phones, wireless local loop phones, tablets, wearable terminal devices, personal digital assistants (PDAs), portable computers, desktop computers, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback devices, in-vehicle wireless terminal devices, wireless endpoints, mobile stations, laptop embedded devices (LEEs), laptop installed devices (LMEs), USB dongles, smart devices, wireless subscriber equipment (CPEs), Internet of Things (IoT) devices, watches or other wearable devices, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in the context of industrial and / or automated processing chains), consumer electronics devices, relay nodes, devices operating on commercial and / or industrial wireless networks, etc. The mobile terminal (MT) portion of an IAB node can perform the functions of a "terminal device" and therefore can operate as a terminal device. In the following description, the terms "terminal device," "communication device," "terminal," "user equipment," and "UE" are used interchangeably.

[0070] To facilitate understanding of the technical solutions provided in the embodiments of this disclosure, some key terms used in the embodiments of this disclosure will be explained below:

[0071] Pilot signals: Generally refers to signals whose content is known in advance at the receiver. In modern communication systems, time and frequency synchronization algorithms, channel estimation, etc., all rely on pilot signals. Pilot signals have different names in different systems, such as reference signals, training sequences, preambles, and center codes. The design of pilot signals is an important technology in communication systems, as pilot signals can assist the receiver in channel estimation, time and frequency synchronization, etc. When pilot signals are used to assist in timing synchronization, pseudo-random (PN) sequences with sharp autocorrelation characteristics are usually used, such as m-sequences, Zadoff-Chu sequences (ZC sequences), and Gold sequences. Code Division Multiple Access (CDMA) systems commonly use m-sequences or Gold sequences, while Long Term Evolution (LTE) systems mainly use ZC sequences as the primary synchronization signal for downlink time synchronization.

[0072] Frequency offset correction: refers to detecting and compensating for the deviation between the received signal and the desired frequency, so that the frequency of the received signal is consistent with that of the transmitted signal, that is, frequency synchronization is achieved, and communication errors caused by frequency drift are avoided.

[0073] Time offset correction: refers to detecting and compensating for the time offset between the received signal and the transmitted signal, so that the time reference of the receiver and the transmitter is kept consistent, that is, time synchronization is achieved.

[0074] Channel: refers to the antenna used to transmit signals. It can be a wireless channel (such as air or electromagnetic waves) or an inertial channel (such as optical fiber or cable). The specific choice depends on the application and requirements of the communication system.

[0075] The Fast Fourier Transform (FFT) is a mathematical transformation that converts a signal from the time domain to the frequency domain, allowing observation of its frequency components. The FFT decomposes a time signal into a superposition of sine or cosine waves of different frequencies, making the signal's frequency domain representation more intuitive and revealing the intensity of each frequency component. It is commonly used in spectrum analysis, signal processing, and other fields to help understand the frequency characteristics of a signal.

[0076] The Discrete Fourier Transform (DFT) is an application of the Fourier Transform to discrete signals, transforming a discrete-time signal into discrete frequency components. Its calculation formula uses a finite number of sample points for frequency domain analysis and is commonly used in signal processing and analysis, including image processing and audio processing.

[0077] Quadrature Phase Shift Keying (QPSK) is a phase modulation method that transmits data by dividing the phase of a signal into four different states (0°, 90°, 180°, 270°), each representing two bits of binary data (00, 01, 10, 11). The key feature of QPSK is its use of phase changes to transmit information and its ability to transmit two bits of binary data per unit time. It is commonly used in wireless communications, such as satellite communications and cellular networks, to provide higher bandwidth utilization and data transmission rates.

[0078] The design concept of the embodiments of this disclosure is briefly introduced below:

[0079] In modern communication systems, pilot signals generally refer to signals whose content is known in advance at the receiver. They assist the receiver in achieving channel estimation and time-frequency synchronization. Time-frequency synchronization technologies such as carrier synchronization and timing synchronization are key technologies for digital receivers, and synchronization performance directly affects whether data can be correctly demodulated.

[0080] However, current pilot signal design schemes generally have limitations. First, because time offset correction and frequency offset correction in existing time-frequency synchronization technologies typically rely on different algorithms and pilot signal characteristics—for example, time synchronization depends on pilot signals with autocorrelation characteristics, while frequency synchronization depends on pilot signals with phase characteristics—time-frequency synchronization in existing systems is usually implemented by two separate and independent technical modules. This makes it impossible to utilize pilots with different characteristics simultaneously, resulting in existing pilot signals only being able to achieve timing synchronization or carrier synchronization individually, but not both simultaneously. Furthermore, existing pilot designs are typically used to assist carrier synchronization, and are only suitable for applications where the frequency offset is much smaller than the symbol rate. They struggle to meet the requirements for simultaneously estimating rapidly changing time and frequency offsets, performing particularly poorly in high-dynamic scenarios with large frequency and time offsets, such as Doppler frequency offset and high frequency offset change rates. This can easily lead to time / frequency synchronization failure, increase frequency estimation errors, and reduce channel estimation efficiency.

[0081] In view of the above problems, embodiments of this disclosure provide a signal processing method. In this method, the transmitting end acquires a first signal with a first characteristic in the frequency domain and a second signal with a second characteristic in the time domain, and generates a pilot signal based on the first and second signals. This combines signals with different characteristics, resulting in a pilot signal that possesses both significant frequency domain characteristics (facilitating frequency offset estimation) and good time domain characteristics (facilitating time synchronization). Conversely, the receiving end acquires a received signal containing the pilot signal and performs time-frequency correction using the first and second characteristics of the pilot signal, thereby achieving time-frequency synchronization. This satisfies the requirement to simultaneously estimate rapidly changing time and frequency offsets, effectively solving problems such as signal distortion and decoding errors caused by time-frequency asynchrony, and improving the synchronization efficiency and data transmission quality of the communication system.

[0082] The following will refer to Figure 1 The principles and implementation of this disclosure are described in detail. The solutions provided in the embodiments of this disclosure are applicable to most communication networks, such as: 5th generation (5G) mobile communication systems or new radio (NR), or other evolved communication systems such as next-generation communication systems, cellular networks, satellite communication systems, wireless local area networks (WLANs), etc., which will not be listed here one by one. Figure 1 The diagram shown is an application scenario provided by an embodiment of this application. In this scenario, a signal receiving device 101, a signal transmitting device 102, and a network 103 may be included.

[0083] The signal receiving device 101, corresponding to the receiving end in this embodiment, can be a terminal device that receives pilot signals and performs time-frequency synchronization processing, such as a mobile phone, personal computer (PC), tablet computer (PAD), laptop computer, desktop computer, mobile internet device (MID), smart wearable device, wireless terminal device in industrial control, ground station or user terminal in satellite network, wireless terminal device in smart grid, wireless terminal device in transportation safety, wireless terminal device in smart city, or wireless terminal device in smart home, etc. This embodiment does not make specific limitations.

[0084] The signal transmitting device 102, corresponding to the transmitting end in this embodiment, is mainly used to generate and transmit pilot signals, and can be a base station, satellite, wireless access point, etc. For example, the signal transmitting device 102 can be any base station capable of providing wireless communication functions for terminal devices, including but not limited to 5th generation (5G) system or new radio (NR) system base station (next generation NodeB, gNB), satellite base station in satellite communication system, evolved NodeB (eNB or eNodeB) in long term evolution (LTE) system, or base station of next-generation communication system.

[0085] The signal receiving device 101 and the signal transmitting device 102 can be connected via a network 103. This network 103 can be a wired network or a wireless network. For example, the wireless network can be a mobile cellular network, such as a 4G, 5G, or New Radio (NR) network, or a Wireless-Fidelity (WIFI) network, a satellite communication network, or any other possible network. This embodiment of the invention does not limit the types of networks that can be used. For instance, in terrestrial wireless communication, pilot signals can be generated by network devices such as base stations, and user equipment receives the pilot signals sent by these devices and performs time-frequency synchronization. Communication within network 103 can conform to any suitable standard, including but not limited to Long Term Evolution (LTE), LTE Evolution, LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), Code Division Multiple Access (CDMA), and Global System for Mobile Communications (GSM). Furthermore, communication can be performed according to any generation of communication protocols currently known or developed in the future. Examples of communication protocols include, but are not limited to, first-generation (1G), second-generation (2G), 2.5G, 2.75G, third-generation (3G), fourth-generation (4G), 4.5G, fifth-generation (5G), and sixth-generation (6G) communication protocols.

[0086] In some embodiments, both the signal receiving device 101 and the signal transmitting device 102 can be terminal devices. The two devices can achieve time-frequency synchronization by exchanging pilot signals to ensure the accuracy and reliability of communication. For example, in decentralized network systems such as device-to-device (D2D) communication, peer-to-peer (P2P) communication, drone self-organizing networks, or direct communication between IoT devices, there is no central base station, and each device needs to synchronize with each other. In this scenario, each device can generate its own pilot signal and use the pilot signals generated by other devices for time-frequency synchronization to complete cooperative communication or relay communication.

[0087] In some embodiments, the signal receiving device 101 and the signal transmitting device 102 may be the same device. That is, the signal processing method provided in this application embodiment may be executed jointly by the signal receiving device 101 and the signal transmitting device 102, or it may be executed by the signal receiving device 101 or the signal transmitting device 102 alone, or it may be executed by a dedicated signal processing device. Taking the dedicated signal processing device executing alone as an example, the signal processing device can generate pilot signals based on the signal processing method provided in this disclosure embodiment, and complete time-frequency synchronization based on the pilot signals.

[0088] It should be noted that, Figure 1 The examples shown are merely illustrative. In reality, the number of signal receiving devices and signal transmitting devices and the communication methods are not limited, and no specific limitations are made in the embodiments disclosed herein.

[0089] Of course, the methods provided in this disclosure are not limited to those described above. Figure 1 The application scenarios shown can also be used in other possible application scenarios, and this disclosure does not impose any limitations. Regarding the above... Figure 1 The functionalities that each device in the application scenario shown can achieve will be described in subsequent method embodiments, and will not be elaborated on here.

[0090] The signal processing method provided by the exemplary embodiments of this disclosure will be described below with reference to the accompanying drawings and the application scenarios described above. It should be noted that the above application scenarios are only shown to facilitate understanding of the spirit and principles of this disclosure, and the embodiments of this disclosure are not limited in any way.

[0091] Figure 2 A flowchart of a pilot signal generation method 200 provided in an embodiment of this disclosure is shown. It should be understood that method 200 may include additional steps not shown and / or some steps shown may be omitted, and the scope of this disclosure is not limited thereto. Method 200 is illustrated using a transmitting end as an example. The transmitting end can be an upper... Figure 1 The specific implementation process of this method for the signal transmitting device shown is as follows:

[0092] Step 201: Obtain the first signal and the second signal.

[0093] In this embodiment of the disclosure, the first signal has a first characteristic in the frequency domain and the second signal has a second characteristic in the time domain. By combining the high-frequency domain concentration of the first signal and the sharp time-domain autocorrelation of the second signal, the pilot signal can simultaneously possess the characteristics of frequency offset and time synchronization. This helps to maintain the stability of time-frequency synchronization in environments with large frequency and time offset rates of change. It is especially suitable for high dynamic scenarios, effectively reducing the bit error rate, ensuring the accuracy of signal demodulation, and improving the overall communication performance.

[0094] In some embodiments, the first characteristic indicates that the power of the first signal is concentrated at a single frequency, that is, the energy of the signal is concentrated at a certain fixed frequency in the frequency domain. This is manifested as a non-zero value only at that frequency point on the spectrum, while the other frequency points are zero or close to zero, making it exhibit a relatively obvious spectral peak. Thus, it presents an obvious spectral peak during frequency domain analysis. Such a clear characteristic makes it easy for the receiver to quickly identify the center frequency of the signal, thereby facilitating subsequent frequency offset estimation and frequency synchronization correction.

[0095] In some embodiments, the first characteristic characterizing the power of the first signal being concentrated at a single frequency specifically means that an impulse response exists in the power spectrum of the first signal. The power spectrum reflects the distribution of signal power at different frequencies and is a core indicator of the signal's frequency domain characteristics. The impulse response refers to the output response of a signal to an impulse input. In the frequency domain, the impulse response manifests as a constant value on the power spectrum, or the signal power is completely concentrated at a certain frequency point. Therefore, the signal corresponding to the impulse response exhibits a single spectral peak in the frequency domain. This frequency concentration allows the receiver to quickly determine the peak position in the spectrum based on the impulse response in the power spectrum, thereby accurately obtaining the frequency offset and facilitating subsequent frequency offset estimation and frequency synchronization correction.

[0096] In some embodiments, the first signal includes a single-tone signal. A single-tone signal is a sinusoidal signal with a single frequency and a spectrum concentrated at a single frequency point. Its characteristic is that its spectrum exhibits an impulse response, representing that the single-tone signal has only one frequency point in its spectrum, with energy concentrated at a single frequency rather than across a wide frequency band. Due to the impulse characteristics of the single-tone signal's spectrum, it is highly sensitive to frequency offset (especially carrier frequency offset), accurately indicating frequency deviation and rapidly locating the frequency position under large frequency offsets. Furthermore, the single-tone signal has a low signal-to-noise ratio, making it simple to implement. This allows the corresponding device to quickly estimate and correct the frequency offset through the frequency offset value, achieving frequency synchronization processing. A single-tone signal can rapidly locate the frequency position under large frequency offsets, as shown in the following equation for a single-tone signal in the time domain:

[0097]

[0098] Where, x F (t) represents the time-domain waveform of a single-tone signal, which can be represented as a sine or cosine wave in the time domain, x F (t) = cos() and x F (t) = sin() represents two time-domain waveform forms of a single-tone signal, both of which exhibit impulse in their spectrum.

[0099] f represents frequency, which is the core parameter for frequency domain analysis. f0 represents the carrier frequency of the single-tone signal, i.e., the center frequency. The transmitting end can set the f0 of the pilot signal, and the receiving end calculates the frequency offset and performs frequency offset correction based on the offset between the detected peak frequency of the received signal and f0.

[0100] t represents time, which is a key variable in the time domain representation, describing the value of the signal at a specific moment. A single-tone signal can be represented as a sine or cosine wave in the time domain.

[0101] G(f) represents x F The Fourier transform of (t) is the frequency domain representation of a single-tone signal. The Fourier transform result of a single-tone signal appears as an impulse peak in the frequency domain.

[0102] δ represents the Dirac function (impulse function). The Fourier transform result of a single-tone signal in the frequency domain is represented by an impulse peak in the form of the Dirac function, indicating that the spectral energy of the signal is concentrated at a specific frequency point.

[0103] In some embodiments, please refer to Figure 3 The figure shows a normalized power spectral density diagram of a single-tone signal provided in an embodiment of this disclosure. The diagram illustrates a 190-bit single-tone signal with a frequency of 1.55 GHz as the first signal. It is clearly visible in Figure x that the spectrum of Pilot_F is concentrated around 1.55 GHz, exhibiting a significant peak. This indicates that almost all the signal energy is concentrated around this frequency, demonstrating high frequency domain concentration. This allows the receiver to accurately estimate the frequency offset by detecting the offset in the spectrum through spectral analysis methods such as Fast Fourier Transform, thus achieving frequency synchronization.

[0104] In some embodiments, the second characteristic represents that the ratio of the main peak to the secondary peak in the autocorrelation result of the second signal is not less than a first threshold. The autocorrelation result of a signal refers to the degree of similarity between the signal and itself at different time delays. This result can be represented by a function, also known as the autocorrelation function. The main peak of the autocorrelation result represents the maximum value of the autocorrelation function. The main peak typically appears at the position where the delay is 0, indicating the moment when the signal is perfectly aligned with itself. The secondary peaks of the autocorrelation function result are other local peaks besides the main peak. They typically appear at moments when the signal repeats periodically or has a similar structure. The magnitude of the secondary peaks reflects the similarity strength of the signals at other delays. The ratio of the main peak to the secondary peak represents the signal's time-domain resolution; that is, the larger the ratio, the more prominent the main peak is relative to the secondary peak, the sharper the autocorrelation characteristic of the signal, and the easier it is to distinguish the starting point of the signal. Thus, by selecting a second signal with a main peak to secondary peak ratio not less than the first threshold, this embodiment of the present disclosure ensures that the second signal has sharp autocorrelation performance in time synchronization, which helps the receiver quickly determine the starting position of the signal, thereby improving the receiver's detection accuracy of the signal's starting point and reducing missynchronization problems caused by secondary peak interference.

[0105] In some embodiments, the second signal includes a PN sequence. A PN sequence is a pseudo-random binary sequence with periodicity and good autocorrelation characteristics. Specifically, within the period, the autocorrelation function value reaches its peak only when the delay is zero, with lower values ​​at other positions. This autocorrelation characteristic makes it superior in time synchronization, facilitating the receiver to confirm the signal's time start point through the autocorrelation result and align the signal's time start point, thereby achieving precise time synchronization and improving its accuracy. Its periodicity also facilitates generation by the transmitter and decoding by the receiver, improving the efficiency of time-frequency synchronization.

[0106] In some embodiments, the PN sequence can be any of the following signals: an m-sequence, a ZC sequence, or a Barker code. These signals all possess sharp autocorrelation characteristics, forming a distinct main peak and relatively low secondary peaks. They exhibit stable time characteristics, especially in environments with multipath interference, frequency-selective channels, and low signal-to-noise ratios, enhancing the receiver's ability to detect pilot signals under complex channel conditions and ensuring robust time synchronization.

[0107] In some embodiments, under large time-off scenarios, the initial position of the signal is unclear, and the pilot signal requires high timing synchronization accuracy. An m-sequence with a period of m is selected as the second signal in this embodiment. Its sharp autocorrelation characteristics bring a significant contrast between the high main peak and the low secondary peak, allowing the receiver to quickly lock the sequence start point, thereby rapidly determining the signal start point under large time-off conditions. Furthermore, the low secondary peak reduces interference at misaligned positions, improving synchronization accuracy. The autocorrelation function corresponding to the m-sequence is shown below:

[0108] b k+m =b k

[0109] Where, r b (j) represents the autocorrelation coefficient of sequence b at interval j, which describes the autocorrelation of sequence b in the time domain, i.e., the similarity of sequence b at different time shifts. The value of the autocorrelation coefficient reflects the degree of correlation between the sequence and itself, and can be used for time synchronization detection in the embodiments of this disclosure.

[0110] m represents the length of sequence b. For sequence m, the length m usually refers to its period, that is, the autocorrelation function will repeat cyclically within one period.

[0111] b k b represents the k-th element in sequence b. k+j Let represent the (k+j)th element in sequence b. Sequence m is a binary sequence with a specific period and pseudo-random properties. Due to the periodicity of sequence m, its value repeats within each period. Therefore, b... k+m equals b k .

[0112] Furthermore, the periodic autocorrelation function of this m-sequence is a binary function, and the ratio of the main peak to the sub-peak is equal to the code length (i.e., the period m). Therefore, its autocorrelation function can be expressed as follows:

[0113]

[0114] Here, j represents the shift of the m-sequence, that is, the relative displacement of the sequence when calculating the autocorrelation function. The autocorrelation function can calculate the correlation of the sequence under different displacements based on different j values.

[0115] m represents the period length of the sequence, and n represents an integer, used to describe that the shift amount j of the sequence is an integer multiple of the period m.

[0116] When the shift amount j is an integer multiple of the period m, i.e., j = nm (n = 0, ±1, ±2, ...), b k =b k+j b k b k+j =1, at which point the value of the autocorrelation function reaches its maximum, that is... The dominant peak value of the autocorrelation function is 1. At this point, the m-sequence is perfectly aligned with itself, indicating the highest correlation of the sequence. For the second signal in this embodiment, this time-domain characteristic helps the receiver accurately locate the starting position of the pilot signal, thereby enabling time synchronization.

[0117] When the shift amount j is not an integer multiple of the period m, i.e., j ≠ nm (n = 0, ±1, ±2, ...), according to the balance of the m-sequence, the number of -1s in one period is one more than the number of 1s. Therefore, the sum of all elements in one period is -1, and the value of the autocorrelation function is... Right now The secondary peak of the autocorrelation function is At this point, the sequence is not perfectly aligned with itself. Apart from the main peak, the correlation at other positions is low, giving the sequence a sharp autocorrelation characteristic, which helps to eliminate noise and interference and improve the accuracy of time synchronization.

[0118] In some embodiments, please refer to Figure 4 The figure shows a schematic diagram of the autocorrelation function of a PN sequence provided in an embodiment of this disclosure. A 63-bit m-sequence is selected as the second signal. The vertical axis represents the autocorrelation function value of the m-sequence, and the horizontal axis represents the time offset t. It is clearly visible in the figure that a sharp main peak exists at time offset t = 0, indicating that the autocorrelation value reaches its maximum when the signal is aligned with itself. Values ​​at other time offsets are close to zero or are small secondary peaks. This sharp autocorrelation characteristic allows the m-sequence to be used to accurately locate the starting position of the signal in the time domain, i.e., to find the reference position for time synchronization, effectively compensating for time offset during signal transmission, ensuring correct signal reception and demodulation, thereby improving the stability and demodulation accuracy of the communication system. In summary, by cross-combining the single-tone signal with strong frequency domain concentration with the PN sequence with strong time domain autocorrelation, the single-tone signal provides a precise frequency reference, and the PN sequence provides a sharp reference point for time synchronization, thus simultaneously satisfying the requirements of frequency synchronization and time synchronization, achieving efficient time-frequency synchronization, and improving the stability and signal processing accuracy of the system.

[0119] Step 202: Generate pilot signals based on the first and second signals.

[0120] In this embodiment of the present disclosure, the transmitting end can generate a pilot signal based on the first signal and the second signal. The pilot signal generated in this way has both the first characteristic of the first signal in the frequency domain and the second characteristic of the second signal in the time domain, so that the receiving end can simultaneously achieve frequency offset correction and time offset correction based on the pilot signal, and quickly complete time-frequency synchronization. Especially in scenarios with large frequency offset and time offset change rates, the stability of time-frequency synchronization is still maintained.

[0121] In some embodiments, this disclosure can perform cross-combination on the first signal and the second signal to generate a pilot signal. Through cross-combination, this disclosure can integrate the first signal and the second signal with different characteristics into the same pilot signal, so that the pilot signal can have synchronization capabilities in both the frequency domain and the time domain. The information required for frequency synchronization and time synchronization can be transmitted at once through the pilot signal, thereby improving the efficiency of time and frequency synchronization.

[0122] In some embodiments, this disclosure can generate a pilot sequence by cross-combining a first signal and a second signal with a first length based on a preset alternating arrangement order. For example, following the preset alternating arrangement order of the first signal first and the second signal second, two bits of the first signal are selected each time, followed by two bits of the second signal, and then combined alternately. The preset alternating arrangement order refers to the transmitting end sequentially combining the symbols of the first and second signals in a certain order. This preset alternating arrangement order ensures that the characteristics of the first and second signals are evenly distributed in the pilot signal, and even if some signals are interfered with, synchronization information can still be recovered from other segments. The first length refers to the length of the signal segment selected from the first and second signals each time during the alternating arrangement. The fixed setting of the first length allows the transmitting and receiving ends to generate and parse the pilot signal according to unified rules, reducing complex calculations and negotiations during communication. The pilot signal generated in this way enables the receiving end to parse the pilot signal more efficiently, quickly distinguish between the first and second signals, and thus achieve frequency and time synchronization. It is worth mentioning that the preset alternating arrangement order and the first length in this disclosure can be set according to actual needs, and the embodiments of this disclosure do not impose specific limitations on them. By presetting the alternating arrangement order, the distribution order of the first signal and the second signal in the pilot signal can be flexibly adjusted, and the distribution ratio of the first signal and the second signal in the pilot signal can be flexibly adjusted by using the first length. In this way, the structure and characteristics of the pilot signal can be customized according to different needs, the pilot signal design can be optimized in different communication scenarios, and the adaptability and performance of the communication system can be improved.

[0123] In some embodiments, after generating the pilot sequence, this disclosure will also modulate the pilot sequence to obtain a pilot signal, so that each symbol in the pilot signal corresponds one-to-one with the signal segment in the pilot sequence, ensuring the stability and predictability of the pilot signal, so that the receiving end can accurately decode and synchronize according to the preset alternating arrangement order and pilot signal structure, thereby improving the demodulation and transmission efficiency of the signal.

[0124] In some embodiments, please refer to Figure 5 The diagram illustrates a cross-combination generation process for pilot signals according to an embodiment of this disclosure. Pilot_F represents the first signal, and in the diagram, it is represented as a single-tone signal Pilot_F = {1,1,1,1,…}

[0125] To illustrate, Pilot_T represents the second signal, illustrated in the diagram using the PN sequence Pilot_T = {a1, a2, a3, a4, ...}. Alternating between Pilot_F and Pilot_T, signal segments of a preset length of two symbols are extracted from each signal segment and combined accordingly. This results in a pilot sequence Pilot = {1, 1, a1, a2, 1, 1, a3, a4, ...}, where each two-bit segment is interpolated. Next, QPSK is used to modulate this Pilot to generate the pilot signal Pilot_symbol, converting each two-bit group of signal segments in the Pilot into a corresponding one-bit symbol in the Pilot_symbol. For example, {1, 1} corresponds to {1}, {a1, a2} corresponds to {b1}, {a3, a4} corresponds to {b2}, and so on.

[0126] It is worth mentioning that Figure 5 Therefore, Pilot_F and Pilot_T are cross-combined in pairs to facilitate the subsequent conversion of each pair of signal segments into a corresponding one-bit signal symbol via QPSK modulation. However, this disclosure does not specifically limit the preset signal length of the signal segments or the modulation method. This disclosure can use any suitable phase shift keying digital modulation method. For example, if BPSK modulation is used, each bit of Pilot_F and Pilot_T can be cross-combined. If 8PSK modulation is used, each three bits of Pilot_F and Pilot_T can be cross-combined. In short, each signal segment in the pilot sequence Pilot obtained by cross-combination corresponds one-to-one with the symbol in the modulated pilot signal.

[0127] In this embodiment of the disclosure, after the pilot signal is generated, it can be transmitted to the receiving end through a channel. However, during signal transmission, the channel may cause problems such as frequency offset, time offset, noise, and interference, resulting in the received signal at the receiving end not being completely consistent with the original transmitted signal at the transmitting end. Therefore, the receiving end needs to perform time-frequency synchronization processing based on the time-frequency characteristics of the pilot signal to eliminate the influence of the channel, ensuring that the frequency and time of the received signal are aligned with those of the transmitting end, thereby achieving time-frequency synchronization and guaranteeing the stability, accuracy, and efficiency of data transmission.

[0128] In some embodiments, during signal transmission, due to the Doppler effect or frequency instability of the device itself, the signal may experience frequency shift during transmission, meaning that the frequency of the received signal obtained by the receiver may differ from the original frequency of the transmitter. Furthermore, noise and interference from other signals may exist in the channel, affecting the accuracy of signal detection and decoding at the receiver. In view of the above problems, reference... Figure 6 The diagram shown is a flowchart of another signal receiving method 600 provided in an embodiment of this application. Method 600 is illustrated using a receiving end as the executing entity. The receiving end can be an upper... Figure 1 The signal receiving device is shown. It should be understood that method 600 may include additional steps not shown and / or some shown steps may be omitted, and the scope of this disclosure is not limited thereto. The specific implementation flow of this method is as follows:

[0129] Step 601: Acquire the received signal.

[0130] In this embodiment of the disclosure, the received signal includes a pilot signal. The pilot signal can be generated by the transmitting end through the aforementioned steps 201-202, and the receiving end obtains the received signal containing the pilot signal transmitted by the transmitting end through the signal.

[0131] In some embodiments, the receiver may perform windowed sampling on the received transmitted signal to obtain a received signal with a frequency peak value greater than a preset peak value threshold. A received signal with a frequency peak value greater than the threshold will exhibit a significant frequency peak value in the frequency domain, ensuring the quality and frequency domain characteristics of the received signal, better resisting noise and interference, and enabling the receiver to more accurately determine the frequency position and provide accurate frequency domain information for subsequent frequency offset estimation and correction processing of the received signal.

[0132] In some embodiments, this disclosure can iteratively perform windowed sampling processing on the transmitted signal until a received signal with a frequency peak value greater than a preset peak value threshold is obtained. Each windowed sampling process includes: windowing the transmitted signal at the beginning position of the window corresponding to this processing to obtain a segment signal of a preset window length; sampling the segment signal according to the odd / even bit position of the first signal in the pilot signal (i.e., the first signal bit number), to obtain a sampled signal, where the signal length ratio between the segment signal and the sampled signal is a preset ratio; when the frequency peak value of the sampled signal is less than the preset peak value threshold, the beginning position of the window is shifted backward based on a preset symbol amount, and the next windowed sampling process is performed according to the shifted beginning position of the window. This windowed sampling process is iteratively performed until the frequency peak value of the sampled signal is greater than the preset peak value threshold, at which point the sampled signal is used as the received signal. Thus, the iterative process aims to find a received signal that meets the conditions, thereby ensuring that subsequent frequency offset estimation and correction can be performed based on high-quality signal segments.

[0133] In some embodiments, windowing refers to applying a window function to a signal to reduce signal edge effects. The windowed signal data is then truncated into a segment for subsequent processing. For example, embodiments of this disclosure may use a Hamming window to window the received signal. In each windowing sampling process, the receiving end will start from the beginning position of the window of the transmitted signal, truncate a segment of signal with a preset window length N, and multiply the Hamming window function sample by sample onto this segment of signal to form a weighted signal segment. This weighted segment gradually changes to zero or a certain value at the beginning and end of the signal, thereby reducing signal edge effects, reducing spectral leakage, and improving the frequency domain analysis accuracy of the signal.

[0134] In some embodiments, sampling processing refers to the process of discretizing a signal, that is, extracting discrete points of the signal from a continuous signal. In this disclosure, the windowed segment signal can be sampled according to the odd or even number of positions (i.e., the number of bits) of the first signal in the pilot signal. For example, when the first signal is in an odd position in the pilot signal, the odd positions of the segment signal are sampled, that is, only the odd-numbered data points in the segment signal are extracted to obtain the values ​​at the odd positions in the segment signal. The length of the sampled signal obtained after sampling is N / 2, which reduces the amount of data and extracts the main information, facilitating subsequent spectral analysis processing such as FFT transformation.

[0135] In some embodiments, the transmitting end can cross-combine a first signal (e.g., Pilot_T) and a second signal (e.g., Pilot_F) in a preset alternating order to generate a pilot signal. For example, the signal segments of the first and second signals can be arranged in odd-numbered and even-numbered positions of the pilot signal, respectively. Correspondingly, the receiving end can perform corresponding sampling processing according to this alternating order to correctly separate and identify different parts of the pilot signal. For example, when the first signal has an odd number of bits, the receiving end's sampling processing needs to sample the segment signal in odd-numbered positions to match the alternating order of the transmitting end. This ensures that the receiving end can correctly decode and extract information from each component of the pilot signal, providing a basis for subsequent time-frequency synchronization processing.

[0136] In some embodiments, after obtaining the sampled signal corresponding to the window position through windowing and sampling processing, frequency domain analysis processing such as FFT transformation can be performed on the sampled signal. FFT transformation can display the energy distribution of the signal at different frequencies, providing a basis for frequency characteristic analysis, thereby converting the time-domain signal to the frequency domain and obtaining frequency domain characteristics such as the spectrum of the sampled signal. The spectrum can represent the amplitude of different frequency components. By observing the peak values ​​of the spectrum and using the frequency domain characteristics such as the spectrum of the sampled signal, the frequency peak position and intensity of the signal can be detected. When the frequency peak value of the sampled signal is less than a preset peak threshold, it indicates that the signal strength of the currently truncated segment is insufficient and may be affected by noise or interference, failing to meet the conditions for frequency offset estimation and correction. Therefore, this segment of signal is not suitable as a received signal. At this point, the starting position of the window can be moved backward according to the preset symbol amount, and the aforementioned windowing sampling process can continue to be performed. For example, the window can be moved backward by one symbol time length so that the new window position covers the next segment of the signal. Then, odd-bit sampling and FFT transformation are performed on the new segment signal. This process is repeated until the frequency peak value of the sampled signal is greater than the preset peak value threshold. The sampled signal is then used as the received signal and as the basis for subsequent frequency offset estimation and correction.

[0137] In some embodiments, the received signal y can be obtained by windowing the transmitted signal with a length N. N and for y N To analyze its frequency domain characteristics, a Discrete Fourier Transform (DFT) is performed. The formula for the DFT is shown below:

[0138]

[0139] Wherein, DFT[y N ] represents the signal y N Perform DFT transformation, Y N (k) represents the output of the DFT transform, i.e., the fragment signal y. NThe frequency domain representation of y is the k-th frequency component in the transformed frequency domain. The DFT transform is used to analyze the characteristics of the received signal in the frequency domain by analyzing y. N By performing a DFT transform, significant frequency components in the spectrum can be identified, thereby allowing the calculation of the shift in frequency peaks.

[0140] N represents the received signal y. N The signal length can be selected as an integer power of 2, which facilitates FFT operations.

[0141] k represents the frequency index of the DFT, indicating different discrete frequency components in the frequency domain.

[0142] n represents the index in the time domain, with a value range of [0, N-1], representing different sampling points of the discrete signal in the time domain, y N (n) represents the signal y N The nth sample value in the time domain.

[0143] W N The fundamental twitch factor representing the DFT indicates the rotation of the unit complex number in the complex plane and is used for weighting and transforming different frequency components of a signal. The power representing the twitch factor is used to calculate the different frequency components of the signal in the frequency domain. According to the definition of DFT, the twitch factor used to calculate the k-th frequency component is W. N The k-th power is the weighting coefficient in the calculation process.

[0144] Furthermore, this embodiment of the disclosure also takes into account the impact of noise; in actual scenarios, the transmitted signal received by the receiving end includes the desired signal component y. N And the noise w(n), as shown below:

[0145] y(n)=y N (n)+w(n)

[0146] Here, w(n) represents the noise signal, which usually comes from environmental interference and system noise, and will affect the received signal and the accuracy of frequency domain analysis.

[0147] Therefore, embodiments of this disclosure will also perform DFT transformation on the transmitted signal with noisy signals, as shown below:

[0148]

[0149] Here, DFT[y] represents the DFT transform of the noisy signal y(n), and Y(k) represents the output result of the DFT transform, that is, the frequency domain representation of the noisy signal y(n). This frequency domain signal consists of two parts: one part is the desired signal y N The transformation result is one part, and the other part is the transformation result of the noise w(n).

[0150] This formula allows for the analysis of the spectral characteristics of the transmitted signal and the estimation of the impact of noise on the frequency domain characteristics. It helps determine whether the frequency peak of the signal is greater than a preset threshold, thereby enabling the selection of a suitable received signal for subsequent processing.

[0151]

[0152] The spectral value Y(k) is affected by noise. Combining this with the DFT transform formula for noisy signals mentioned above, we know that when the desired signal y... N The more "1" signs it contains, the better it is for y N The larger the Y(k) spectrum value obtained after Fourier transform, the better it can be used to judge the quality of the signal. This allows the receiver to determine the validity of the signal segment by judging whether the peak value of the spectrum exceeds a preset threshold, thereby helping the receiver to filter out high-quality signal segments, improve the accuracy of frequency offset estimation and correction, and ensure the stability of time and frequency synchronization.

[0153] Step 602: Based on the first and second characteristics of the pilot signal, perform time-frequency correction on the received signal to complete the time-frequency synchronization of the receiver.

[0154] In this embodiment of the present disclosure, the receiving end can quickly locate the frequency offset by the first characteristic of the pilot signal in the frequency domain, and achieve accurate frequency offset correction. Based on the second characteristic of the pilot signal in the time domain, it can accurately detect the time offset and achieve time offset correction. Thus, with a single transmission of the pilot signal, the receiving end can simultaneously achieve frequency synchronization and time synchronization, meeting the requirement of simultaneously estimating rapidly changing time and frequency offsets.

[0155] In some embodiments, this disclosure can perform frequency offset correction on the received signal based on a frequency offset estimate to obtain a frequency synchronization signal. The frequency offset estimate is determined based on the peak frequency of the received signal and the center frequency of the pilot signal. The frequency synchronization signal represents that, after frequency offset correction, the frequency of the received signal is consistent with or nearly consistent with the pilot signal at the transmitting end, indicating that the receiving end has successfully compensated for the frequency offset, aligning the signal frequency with the transmitting end, and providing a basis for subsequent demodulation, decoding, and time synchronization.

[0156] In some embodiments, the frequency offset estimate represents the difference between the received signal and the pilot signal in the frequency domain, reflecting the frequency offset of the signal during channel transmission.

[0157] In some embodiments, the frequency offset estimate can be calculated by comparing the center frequency point corresponding to the peak frequency of the received signal with the center frequency point of the pilot signal. The center frequency point corresponding to the peak frequency of the received signal represents the dominant frequency position of the received signal in the frequency domain. It is usually the strongest frequency component of the signal obtained by the receiver through spectrum analysis. For example, the center frequency point corresponding to the peak frequency can be determined by the spectrum diagram of the received signal.

[0158] In some embodiments, the first center frequency point corresponding to the peak frequency of the received signal can be denoted as f1, and f1 can be compared with the center frequency point f0 of the pilot signal before transmission through the channel to obtain the frequency offset estimate f = |f1 - f0|. By calculating the frequency offset estimate, the receiver can identify and compensate for the frequency offset caused by factors such as the Doppler effect and hardware instability during signal transmission. This frequency offset correction can improve the demodulation accuracy of the received signal, reduce signal distortion, and ensure frequency synchronization consistency between the receiver and the transmitter.

[0159] In some embodiments, by using the calculated frequency offset estimate, this disclosure can combine various frequency offset correction methods such as phase rotation, digital mixing, and FFT frequency domain compensation to eliminate the frequency error introduced during signal transmission, ensuring that the signal frequency remains consistent with the transmitting end. For example, applying phase compensation to the received signal, mixing the received signal with a local oscillator signal at a certain compensation frequency, or shifting the signal spectrum to move the frequency offset portion to the original frequency position, so that the corrected signal spectrum is aligned with the original signal spectrum, reducing demodulation errors caused by frequency offset. Furthermore, appropriate frequency offset correction methods can be selected according to actual needs, and this disclosure does not specifically limit these methods.

[0160] In some embodiments, since the signal is affected by propagation delay, multipath effect and other factors during propagation, the received signal obtained by the receiver is out of sync with the transmitter in time. Therefore, in this embodiment, after frequency offset correction of the received signal by frequency offset estimation to complete frequency synchronization, time offset correction and time synchronization will also be performed by the frequency synchronization signal obtained after frequency offset correction.

[0161] In some embodiments, this disclosure can perform time offset correction on the received signal based on a time offset estimate. The time offset estimate, obtained from the frequency synchronization signal, is an important parameter reflecting the time offset between the received signal and the pilot signal, representing the time offset caused by channel delay, hardware mismatch, etc., during signal transmission. Through time offset correction, this disclosure can compensate for this time offset, ensuring that the time reference of the received signal is consistent with that of the transmitting end, laying the foundation for subsequent data demodulation and channel processing.

[0162] In some embodiments, the time offset estimate represents the difference between the received signal and the pilot signal in the time domain. Thus, the time offset estimate allows adjustment of the received signal's position in the time domain to align it with the transmitted signal, thereby achieving time synchronization.

[0163] In some embodiments, this disclosure may select appropriate time offset correction methods according to actual scenario requirements such as the magnitude of time offset, signal characteristics, system complexity, and accuracy requirements. For example, for simple fixed time offsets, time shifting or delay compensation methods can be used, while for complex and changing time offsets, interpolation resampling, phase compensation, or feedback control methods can be used. This disclosure does not specifically limit these methods.

[0164] In some embodiments, this disclosure can perform symbol filtering on the spectrum synchronization signal based on the frequency peak value of the received signal to obtain a time-domain processed signal, thereby obtaining a time offset estimate through the time-domain correlation function of the time-domain processed signal.

[0165] In some embodiments, this disclosure can filter out frequency-domain associated symbols in the frequency synchronization signal based on the symbol start position of the frequency peak. The frequency-domain associated symbols are those whose start positions in the frequency synchronization signal are at the same odd / even bit position.

[0166] In some embodiments, the symbol start position corresponding to the peak frequency of the received signal in this disclosure represents the position of the symbol corresponding to that peak frequency in the signal sequence, used to indicate the symbol position where the spectral peak is located, and can serve as the starting point for signal timing and frequency domain characteristics. By determining the symbol start position, the receiver can accurately perform time-frequency alignment of the signal, laying the foundation for time offset correction and time synchronization. Frequency-domain associated symbols and symbol start positions are located at the same odd or even positions in the frequency synchronization signal. Since frequency-domain associated symbols exhibit similar spectral characteristics to symbol start positions in the frequency domain, their presence may interfere with the time characteristics of the time-domain processed signal. Therefore, by filtering out frequency-domain associated symbols, time-domain features related to the pilot signal can be extracted, meaning that the time-domain processed signal mainly contains the second signal component related to time-domain synchronization in the pilot signal, which can achieve more accurate time-domain alignment and improve the synchronization stability and signal processing accuracy of the communication system.

[0167] In some embodiments, this disclosure may determine a corresponding symbol as a frequency-domain associated symbol when the remainder between the index difference of each symbol in the frequency synchronization signal and a preset target value is zero, before filtering out frequency-domain associated symbols in the frequency synchronization signal. Here, the index difference represents the difference between the position index of the corresponding symbol and the symbol's starting position.

[0168] In some embodiments, this disclosure can obtain corresponding index differences by comparing the position indices of each signal symbol in the frequency synchronization signal with the symbol start position. When the remainder between the index difference and a preset target value is zero, the corresponding signal symbol is determined to be a frequency domain associated symbol. For example, for each symbol in the frequency synchronization signal, its position index i and symbol start position L are calculated respectively. s The difference between them, i.e., the index difference |iL s |. By confirming |iL s | whether the value of mod 2 is equal to zero; if so, it means that the symbol belongs to the AND variable L. s The sign that is modulo 2 congruent, that is, the sign that is congruent to L. s Those with the same parity in the position index belong to the frequency domain associated symbols, while those with L are excluded. s The modulo-2 congruent frequency domain association symbol is used to reduce the first signal (Pilot_F) component and retain the second signal (Pilot_T) component, thereby achieving separation of Pilot_F and Pilot_T.

[0169] In some embodiments, only the received signal y is considered. N The FFT transforms the received signal y. N The DFT formula is divided into two parts: odd-numbered digits and even-numbered digits, that is, y N (0),y N (2),...take each term as an even-numbered term, and y N (1),y N (3),... terms are taken out as odd-numbered terms, thus affecting the received signal y N The FFT transform is used to perform parity decomposition, and the frequency domain representations of the even and odd terms are obtained as follows:

[0170]

[0171] Here, Y1(k) and Y2(k) represent the FFT transformation results of even-numbered and odd-numbered terms, respectively.

[0172] y N (2n) and y N (2n+1) represent the sampling points at even-numbered and odd-numbered positions in the signal, respectively. Thus, by separating the signals at even-numbered and odd-numbered positions, the separation of Pilot_F and Pilot_T can be achieved more effectively.

[0173] Furthermore, in this embodiment of the present disclosure, when the first signal Pilot_F is set to a single-tone signal composed of all 1 symbols, the even-numbered terms p(0), p(2), ... of the received signal are all 1 symbols, and the received signal y is truncated without considering the influence of noise. NIn the diagram, if all 1s are located in an even number of positions, then for the received signal y... N The FFT transform is used to perform parity decomposition, and the frequency domain representations of the even and odd terms are shown below:

[0174]

[0175] Among them, Y N (k) The maximum value is the value of the truncated received signal y, which is obtained without considering noise. N When all even-numbered positions are "1" signs (i.e., Pilot_F), the FFT transform result will reach its maximum value at even-numbered positions.

[0176] At this point, considering the impact of noise, a preset peak threshold p is set. When Y(k) > p, it indicates that the receiver has successfully received the pilot signal. The frequency offset estimate can be calculated by analyzing the FFT impulse position, and the symbol start position L can be determined. s This allows for the identification of even and odd bits in the signal, enabling the separation and extraction of Pilot_F and Pilot_T. The time-domain and frequency-domain characteristics of these two elements are then utilized to achieve frequency and time synchronization, preventing mutual interference.

[0177] In some embodiments, this disclosure can obtain the correlation function graph of the time-domain processed signal in the time domain, i.e., the time-domain correlation function, through the sliding correlation method. The sliding correlation method calculates the correlation value at each position by sliding a reference sequence across the signal, thereby capturing the periodicity and peak position of the signal in the time domain and obtaining the correlation function graph. For example, to find a specific sequence p in the signal sequence [s1,s2,…,sN], the signal sequence is slid, and the correlation coefficient with p is calculated point by point, resulting in a series of correlation values. When a significant correlation peak appears, it indicates that the position of sequence p has been found. The time-domain correlation function is used to describe the correlation between the signal and itself at different time delays. This disclosure can determine the time offset estimate of the signal by analyzing the peak position of the time-domain correlation function.

[0178] In some embodiments, this disclosure can obtain a time offset estimate based on the difference between the peak time of the time-domain correlation function and the reception duration. Here, the peak time is the time point corresponding to the peak value of the time-domain correlation function, and the reception duration is the duration between the peak time and the start time of the received signal.

[0179] In some embodiments, this disclosure can use a correlation function graph to determine the peak time t0 corresponding to the peak value when the peak value of the correlation function exceeds a preset threshold, and determine the duration Δt0 between the peak time t0 and the start time of the original received signal. The time offset estimate Δt = |t0 - Δt0| can be calculated using t0 and Δt0.

[0180] In some embodiments, after separating Pilot_F and Pilot_T in the received signal, the received signal y(n) has had the all-1 sequence Pilot_F removed. The receiver can then perform sliding correlation calculations with a length of L, for example, sliding one symbol at a time. In this embodiment, when the PN sequence is set as the second signal Pilot_T, due to the sharp autocorrelation characteristics of the PN sequence, the starting point of Pilot_T can be determined using the sliding correlation method. That is, each acquired signal sequence of length L is denoted as y. L Let the known pilot sequence be denoted as p, and for y L Performing sliding-related calculations with p, we obtain the following formula:

[0181]

[0182] Here, Z(k) represents the sliding correlation value. As k changes, Z(k) reflects the relationship between the pilot sequence p and the signal sequence y. L The degree of similarity at different sliding positions. When Z(k) reaches its maximum value or exceeds the set threshold, it indicates that the signal matching degree is relatively high.

[0183] p(i) represents the i-th symbol in the known pilot sequence. Due to the sharp autocorrelation characteristic of Pilot_T, when the pilot sequence p and the signal sequence y... L When the alignment is correct, the autocorrelation value will show a significant peak.

[0184] y L (ik) represents the signal sequence y L The ikth symbol in the sequence. As the sliding window moves, the index position of the signal sequence changes accordingly, which is used to calculate the sliding correlation value.

[0185] L0 represents the length of the pilot sequence p, and L represents the signal sequence y. L The length of L0, and L0 <L。

[0186] k represents the offset or delay of the slide. As k changes, the pilot sequence p changes in the signal sequence y. L The starting position in the calculation will change continuously, thereby calculating the relevant values ​​at different positions.

[0187] In summary, considering the impact of noise, the embodiments of this disclosure can set the peak threshold p′ of the correlation function. During the sliding process, once Z(k)>p′ occurs, it indicates that the matching degree between the signal and the pilot sequence is relatively high, representing the capture of the starting point t0 of the pilot signal. Thus, based on the time Δt0 between the time point t0 and the starting time of the original received signal, the time offset estimate Δt=|t0-Δt0| is calculated.

[0188] The basic concepts have been described above. It is clear that the above disclosure is merely illustrative and does not constitute a limitation of this disclosure. Although not explicitly stated herein, various modifications, improvements, and corrections may be made to this disclosure by those skilled in the art. Such modifications, improvements, and corrections are suggested in this disclosure and therefore remain within the spirit and scope of the exemplary embodiments of this disclosure.

[0189] Furthermore, this disclosure uses specific terms to describe embodiments of the present disclosure. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic associated with at least one embodiment of the present disclosure. Therefore, it should be emphasized and noted that references to "an embodiment," "one embodiment," or "an alternative embodiment" in different locations throughout this specification do not necessarily refer to the same embodiment. Moreover, certain features, structures, or characteristics in one or more embodiments of the present disclosure can be appropriately combined.

[0190] Please refer to Figure 7 The diagram illustrates the interaction between a transmitter and a receiver according to an embodiment of this disclosure. First, the transmitter interpolates Pilot_F and Pilot_T in pairs, cross-combining them to obtain a pilot sequence. This pilot sequence is then QPSK modulated to obtain the pilot signal of this disclosure, which is transmitted to the receiver. The receiver receives the signal transmitted from the transmitter through the communication channel and stores it in a buffer for subsequent processing. This received signal includes the pilot signal generated by the transmitter and any other possible data signals. The buffer temporarily stores segments of the received signal, ensuring that complete signal data can be read during windowing. Next, the receiver performs windowing processing on the received signal, truncating a segment of the signal according to the window length for subsequent frequency domain analysis. A Hamming window or other window functions are typically used. Based on the first number of signal bits, the receiver samples the truncated signal segment with an odd number of bits, retaining only the sampling points at odd positions, thereby reducing the data volume while preserving key characteristics. The receiver performs an FFT transform on the signal segment after odd-numbered sampling, converting the signal from the time domain to the frequency domain to obtain its frequency characteristics and generate a spectrum. From the obtained spectrum, the receiver can determine whether the peak frequency of the sampled signal is greater than a preset peak threshold. If the peak frequency is less than the preset threshold, it indicates that the signal quality of that segment does not meet the requirements. The receiver then moves the window start position backward by a preset number of symbols, for example, by one symbol, and re-windows and re-samples. This process is repeated until the peak frequency of the sampled signal is greater than the preset threshold. The first center frequency point f1 corresponding to the peak frequency of the sampled signal, and the corresponding symbol start position L, are then determined. sThe first center frequency point f1 is compared with the center frequency point f0 of the pilot signal before transmission through the channel, and the frequency offset estimate f = |f1-f0| is calculated. Therefore, the frequency offset estimate f is used to correct the frequency offset of the received signal stored in the buffer to compensate for the frequency shift between the received signal and the transmitter. For the frequency synchronization signal obtained after frequency offset correction, symbols with the symbol start position L are removed. s Modulo-2 congruent frequency domain correlation symbols are used to retain the time-domain correlated portion of the signal and reduce interference. Next, the sliding correlation method is used to perform correlation calculations on the filtered time-domain processed signal, obtaining a correlation function graph in the time domain. Based on this graph, the position of the correlation peak exceeding a set threshold and the corresponding peak time t0 are determined. The reception duration Δt0 from the start time of the received signal to the peak time t0 is calculated, and the time offset estimate Δt = |t0 - Δt0| is further obtained. Therefore, time offset correction is performed on the received signal based on the time offset estimate, aligning the time base of the received signal with that of the transmitter, thus completing time-frequency synchronization at the receiver.

[0191] Please see Figure 8 Based on the same inventive concept, embodiments of this application also provide a pilot signal generation device 80, applied at the transmitting end, such as the above. Figure 1 The signal transmitting device shown includes:

[0192] The acquisition unit 801 is used to acquire a first signal and a second signal, wherein the first signal has a first characteristic in the frequency domain and the second signal has a second characteristic in the time domain;

[0193] The generation unit 802 is used to generate pilot signals based on the first signal and the second signal.

[0194] Optionally, the first characteristic indicates that the power of the first signal is concentrated at a single frequency.

[0195] Optionally, the second characteristic indicates that the ratio of the main peak to the sub-peak in the autocorrelation result of the second signal is not less than the first threshold.

[0196] Optionally, generation unit 802 is specifically used for:

[0197] The first and second signals are cross-combined to generate pilot signals.

[0198] Optionally, generation unit 802 is specifically used for:

[0199] Based on a preset alternating arrangement order, the first signal and the second signal are cross-combined with a first length to generate a pilot sequence.

[0200] Optionally, after generating the pilot sequence, generation unit 802 is specifically used for:

[0201] The pilot sequence is modulated to obtain the pilot signal.

[0202] Optionally, the first characteristic characterizes the power of the first signal as concentrated at a single frequency, specifically: the power spectrum of the first signal contains an impulse response.

[0203] Optionally, the first signal may include a single-tone signal.

[0204] Optionally, the second signal may include a PN sequence.

[0205] Optionally, the PN sequence can be an m-sequence, a ZC sequence, or a Barker code.

[0206] Please see Figure 9 Based on the same inventive concept, this application also provides a pilot signal receiving device 90, applied at the receiving end, such as the above. Figure 1 The signal receiving device shown includes:

[0207] The receiving unit 901 is used to acquire the received signal, which includes the pilot signal;

[0208] The correction unit 902 is used to perform time-frequency correction on the received signal based on the first and second characteristics of the pilot signal in order to complete the time-frequency synchronization of the receiver.

[0209] Optionally, the receiving unit 901 is specifically used for:

[0210] The received transmission signal is windowed and sampled to obtain the received signal; the peak frequency of the received signal is greater than a preset peak threshold.

[0211] Optionally, the correction unit 902 is specifically used for:

[0212] Frequency offset correction is performed on the received signal based on the frequency offset estimate to obtain a frequency synchronization signal; the frequency offset estimate is determined based on the peak frequency of the received signal and the center frequency of the pilot signal.

[0213] Optionally, after obtaining the frequency synchronization signal, the correction unit 902 is specifically used for:

[0214] The received signal is time-biased based on the time-bias estimate, which is obtained based on the frequency synchronization signal.

[0215] Optionally, the frequency offset estimate characterizes the difference between the received signal and the pilot signal in the frequency domain.

[0216] Optionally, the time offset estimate characterizes the difference between the received signal and the pilot signal in the time domain.

[0217] Optionally, the correction unit 902 is specifically used for:

[0218] Based on the frequency peak value of the received signal, the spectrum synchronization signal is symbol-filtered to obtain the time-domain processed signal;

[0219] The time offset estimate is obtained by processing the time-domain correlation function of the signal in the time domain.

[0220] Optionally, the correction unit 902 is specifically used for:

[0221] Frequency-domain associated symbols in the frequency synchronization signal are filtered out based on the symbol start position of the frequency peak; the frequency-domain associated symbols and the symbol start position in the frequency synchronization signal are in the same odd or even position.

[0222] Optionally, before filtering out frequency-domain associated symbols in the frequency synchronization signal, the correction unit 902 is specifically used for:

[0223] When the remainder between the index difference of each symbol in the frequency synchronization signal and the preset target value is zero, the corresponding symbol is determined to be a frequency domain associated symbol; the index difference represents the difference between the position index of the corresponding symbol and the starting position of the symbol.

[0224] Optionally, the correction unit 902 is specifically used for:

[0225] The time offset estimate is obtained based on the difference between the peak time of the time-domain correlation function and the reception duration; the peak time is the time point corresponding to the peak value of the time-domain correlation function, and the reception duration is the duration between the peak time and the start time of the received signal.

[0226] For ease of description, the above sections are divided into functional units (or modules) and described separately. Of course, in implementing this application, the functions of each unit (or module) can be implemented in one or more software or hardware components. This device can be used to execute the methods shown in the embodiments of this application; therefore, the functions that each functional module of the device can achieve can be referred to the descriptions of the foregoing embodiments, and will not be repeated here.

[0227] Please see Figure 10 As shown, based on the same technical concept, this application also provides a computer device 100. In one embodiment, the computer device can be a pilot signal generating device and / or a pilot signal receiving device. Figure 10 As shown, it includes a memory 1001, a communication module 1003, and one or more processors 1002.

[0228] The memory 1001 is used to store computer programs executed by the processor 1002. The memory 1001 may mainly include a program storage area and a data storage area. The program storage area may store the operating system and programs required to run instant messaging functions, etc.; the data storage area may store various instant messaging information and operation instruction sets, etc.

[0229] Memory 1001 may be volatile memory, such as random-access memory (RAM); memory 1001 may also be non-volatile memory, such as read-only memory, flash memory, hard disk drive (HDD), or solid-state drive (SSD); or memory 1001 may be any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but is not limited thereto. Memory 1001 may be a combination of the above-described memories.

[0230] The processor 1002 may include one or more central processing units (CPUs) or digital processing units, etc. The processor 1002 is used to implement the above-described pilot signal generation method and / or pilot signal receiving method when calling the computer program stored in the memory 1001.

[0231] The communication module 1003 is used to communicate with other terminal devices or other base stations.

[0232] This application embodiment does not limit the specific connection medium between the memory 1001, communication module 1003, and processor 1002. This application embodiment... Figure 10 The memory 1001 and the processor 1002 are connected via a bus 1004, and the bus 1004 is in Figure 10 The diagram uses thick lines to describe the connections between other components; these are for illustrative purposes only and should not be considered limiting. Bus 1004 can be divided into address bus, data bus, control bus, etc. For ease of description, Figure 10 It is described using only a thick line, but does not indicate that there is only one bus or one type of bus.

[0233] The memory 1001 stores a computer storage medium, which stores computer-executable instructions. The computer-executable instructions are used to implement the pilot signal generation method and / or pilot signal receiving method of the embodiments of this application. The processor 1002 is used to execute the pilot signal generation method and / or pilot signal receiving method of the above embodiments.

[0234] In some embodiments, various aspects of the pilot signal generation method and / or pilot signal receiving method provided in this application can also be implemented in the form of a program product, which includes program code. When the program product is run on a computer device, the program code is used to cause the computer device to perform the steps in the pilot signal generation method and / or pilot signal receiving method according to various exemplary embodiments of this application described above. For example, the computer device can execute the steps of each embodiment.

[0235] The program product may employ any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples (a non-exhaustive list) of readable storage media include: electrical connections having one or more wires, portable disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0236] The program product of the embodiments of this application may employ a portable compact disc read-only memory (CD-ROM) and include program code, and may run on a computing device. However, the program product of this application is not limited thereto. In this application, the readable storage medium may be any tangible medium that contains or stores a program that may be used by or in conjunction with a command execution system, apparatus, or device.

[0237] A readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, carrying readable program code. This propagated data signal may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A readable signal medium may also be any readable medium other than a readable storage medium, capable of sending, propagating, or transmitting a program for use by or in conjunction with a command execution system, apparatus, or device.

[0238] The program code contained on the readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, RF, etc., or any suitable combination thereof.

[0239] Program code for performing the operations of this application can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java and C++, and conventional procedural programming languages ​​such as C or similar languages. The program code can execute entirely on the user's computing device, partially on the user's device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0240] It should be noted that although several units or sub-units of the device have been mentioned in the detailed description above, this division is merely exemplary and not mandatory. In fact, according to embodiments of this application, the features and functions of two or more units described above can be embodied in one unit. Conversely, the features and functions of one unit described above can be further divided and embodied by multiple units.

[0241] Furthermore, although the operations of the method of this application are described in a specific order in the accompanying drawings, this does not require or imply that these operations must be performed in that specific order, or that all the operations shown must be performed to achieve the desired result. Additionally or alternatively, certain steps may be omitted, multiple steps may be combined into one step, and / or one step may be broken down into multiple steps.

[0242] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0243] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0244] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

[0245] Some aspects of this disclosure can be executed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The aforementioned hardware or software may be referred to as a "data block," "module," "engine," "unit," "component," or "system." The processor may be one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DAPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, or combinations thereof. Furthermore, aspects of this disclosure may be embodied as computer products residing in one or more computer-readable media, including computer-readable program code. For example, computer-readable media may include, but are not limited to, magnetic storage devices (e.g., hard disks, floppy disks, magnetic tapes, etc.), optical discs (e.g., compressed CDs, digital multifunction DVDs, etc.), smart cards, and flash memory devices (e.g., cards, sticks, key drives, etc.).

[0246] A computer-readable medium may contain a propagated data signal containing computer program code, for example, on baseband or as part of a carrier wave. This propagated signal may take various forms, including electromagnetic, optical, and so on, or suitable combinations thereof. A computer-readable medium can be any computer-readable medium other than a computer-readable storage medium, which can be connected to an instruction execution system, apparatus, or device to enable communication, propagation, or transmission of a program for use. The program code located on the computer-readable medium can be propagated through any suitable medium, including radio, cable, fiber optic cable, radio frequency signals, or similar media, or any combination of the above media.

[0247] Similarly, it should be noted that, in order to simplify the description of this disclosure and thus aid in the understanding of one or more embodiments of the invention, multiple features may sometimes be grouped into a single embodiment, drawing, or description thereof in the foregoing description of the embodiments of this disclosure. However, this method of disclosure does not imply that the subject matter of this disclosure requires more features than those mentioned. In fact, the embodiments contain fewer features than all the features of the single embodiments disclosed above.

[0248] In some embodiments, numbers describing the quantity of components and attributes are used. It should be understood that such numbers used in the description of embodiments are modified in some examples by the terms "approximately," "approximately," or "generally." Unless otherwise stated, "approximately," "approximately," or "generally" indicates that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in this disclosure are approximate values, which may be changed according to the characteristics required by individual embodiments. In some embodiments, numerical parameters should take into account specified significant digits and employ a general method of digit preservation. Although the numerical ranges and parameters used in some embodiments of this disclosure to confirm their breadth of range are approximate values, in specific embodiments, such numerical values ​​are set as precisely as feasible.

[0249] Although this disclosure has been described with reference to specific embodiments, those skilled in the art should recognize that the above embodiments are merely illustrative of this disclosure, and various equivalent changes or substitutions can be made without departing from the spirit of this disclosure. Therefore, any changes or modifications to the above embodiments within the scope of the essential spirit of this disclosure will fall within the scope of this disclosure.

Claims

1. A method for generating pilot signals, characterized in that, Applied to the sending end, the method includes: Acquire a first signal and a second signal, wherein the first signal has a first characteristic in the frequency domain and the second signal has a second characteristic in the time domain; A pilot signal is generated based on the first signal and the second signal.

2. The method as described in claim 1, characterized in that, The first characteristic indicates that the power of the first signal is concentrated at a single frequency.

3. The method as described in claim 1, characterized in that, The second characteristic indicates that the ratio of the main peak to the secondary peak in the autocorrelation result of the second signal is not less than the first threshold.

4. The method as described in claim 1, characterized in that, The generation of pilot signals based on the first signal and the second signal includes: The first signal and the second signal are cross-combined to generate the pilot signal.

5. The method as described in claim 4, characterized in that, The step of performing cross-combination on the first signal and the second signal includes: Based on a preset alternating arrangement order, the first signal and the second signal are cross-combined with a first length to generate a pilot sequence.

6. The method as described in claim 5, characterized in that, After generating the pilot sequence, the method further includes: The pilot sequence is modulated to obtain the pilot signal.

7. The method as described in claim 2, characterized in that, The first characteristic characterizes that the power of the first signal is concentrated at a single frequency, specifically: the power spectrum of the first signal contains an impulse response.

8. The method as described in claim 2, characterized in that, The first signal includes a single-tone signal.

9. The method as described in claim 3, characterized in that, The second signal includes a PN sequence.

10. The method as described in claim 9, characterized in that, The PN sequence is an m-sequence, a ZC sequence, or a Barker code.

11. A method for receiving pilot signals, characterized in that, Applied to the receiving end, the method includes: Acquire a received signal, the received signal including a pilot signal; Based on the first and second characteristics of the pilot signal, the received signal is time-frequency corrected to achieve time-frequency synchronization at the receiving end.

12. The method of claim 11, characterized in that, The acquisition of the received signal includes: The received transmission signal is subjected to windowed sampling processing to obtain the received signal; the peak frequency of the received signal is greater than a preset peak threshold.

13. The method as described in claim 11, characterized in that, The time-frequency correction of the received signal includes: The received signal is frequency offset corrected based on the frequency offset estimate to obtain a frequency synchronization signal; the frequency offset estimate is determined based on the frequency peak value of the received signal and the center frequency point of the pilot signal.

14. The method as described in claim 13, characterized in that, After obtaining the frequency synchronization signal, the method further includes: The received signal is time-biased based on the time-biased estimate; the time-biased estimate is obtained based on the frequency synchronization signal.

15. The method as described in claim 13, characterized in that, The frequency offset estimate characterizes the difference between the received signal and the pilot signal in the frequency domain.

16. The method as described in claim 14, characterized in that, The time offset estimate characterizes the difference between the received signal and the pilot signal in the time domain.

17. The method as described in claim 14, characterized in that, The time offset estimate is obtained based on the frequency synchronization signal, including: Based on the frequency peak value of the received signal, the frequency synchronization signal is symbol-filtered to obtain a time-domain processed signal. The time offset estimate is obtained based on the time-domain correlation function of the time-domain processed signal.

18. The method as described in claim 17, characterized in that, The symbol filtering of the frequency synchronization signal includes: Based on the symbol start position of the frequency peak, frequency-domain associated symbols in the frequency synchronization signal are filtered out; the frequency-domain associated symbols and the symbol start position in the frequency synchronization signal are at the same odd or even position.

19. The method as described in claim 18, characterized in that, Before filtering out frequency-domain associated symbols in the frequency synchronization signal, the method further includes: When the remainder between the index difference of each symbol in the frequency synchronization signal and the preset target value is zero, the corresponding symbol is determined to be the frequency domain associated symbol; the index difference represents the difference between the position index of the corresponding symbol and the starting position of the symbol.

20. The method as described in claim 17, characterized in that, The process of obtaining the time offset estimate based on the time-domain correlation function of the time-domain processed signal includes: The time offset estimate is obtained based on the difference between the peak time of the time-domain correlation function and the reception duration; the peak time is the time point corresponding to the peak value of the time-domain correlation function, and the reception duration is the duration between the peak time and the start time of the received signal.

21. A pilot signal generation device, characterized in that, Applied to the transmitting end, the device includes: An acquisition unit is used to acquire a first signal and a second signal, wherein the first signal has a first characteristic in the frequency domain and the second signal has a second characteristic in the time domain; The generation unit is used to generate pilot signals based on the first signal and the second signal.

22. A pilot signal receiving device, characterized in that, Applied to the receiving end, the device includes: A receiving unit is used to acquire a received signal, the received signal including a pilot signal; The correction unit is used to perform time-frequency correction on the received signal based on the first and second characteristics of the pilot signal, so as to complete the time-frequency synchronization of the receiving end.

23. A computer device, characterized in that, include: At least one processor; as well as At least one memory storing instructions that, when executed individually or jointly by the at least one processor, cause the computing device to perform the method according to any one of claims 1 to 10 and / or 11 to 20.

24. A computer storage medium storing instructions thereon, characterized in that, When executed individually or jointly by at least one processor of the computing device, the instructions cause the computing device to perform the method according to any one of claims 1 to 10 and / or 11 to 20.

25. A computer program product, comprising instructions, characterized in that, When executed individually or jointly by at least one processor of the computing device, the instructions cause the computing device to perform the method according to any one of claims 1 to 10 and / or 11 to 20.

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