Apparatus and method for afdm-based pilot signal generation

Abstract

This disclosure relates to a network entity for generating chirped pilot signals, comprising: obtaining a first parameter set from a core network device, wherein the first parameter set includes: the number of pilot sequences to be generated, a time-domain chirp rate, and a frequency-domain chirp rate; obtaining N pilot sequences based on the first parameter set, wherein each pilot sequence includes a set of K pilot chirped carrier samples, where K is an integer not less than N; for each antenna port of the network entity, determining a subset of the N pilot sequences, and synthesizing a pilot signal to be transmitted from the antenna port based on the newly formed set of K samples, wherein each of the K samples is obtained by summing the corresponding samples of the K samples of each pilot sequence in the determined subset of the N pilot sequences.

Description

Technical Field

[0001] This disclosure relates to the fields of wireless communication and radar sensing, specifically focusing on technologies and systems within the integrated sensing and communication (ISAC) paradigm. More specifically, this disclosure proposes a network entity and corresponding method for generating chirped pilot signals in wireless communication networks. Background Technology

[0002] The convergence of wireless communication and radar sensing towards the ISAC paradigm marks a crucial shift in the field, driven by goals such as reducing power consumption, improving spectral efficiency, and lowering hardware costs. This convergence presents challenges to traditional paradigms, necessitating the adoption of new approaches in system design and signal processing.

[0003] Chirped frequency-modulated continuous wave (FMCW) radar is renowned for its excellent sensing capabilities and processing simplicity, but it faces integration challenges within the ISAC framework, especially in the context of the evolving 6G technology. Traditional integration methods such as time-division multiplexing (TDM) have revealed efficiency bottlenecks, prompting the development of more innovative solutions.

[0004] Emerging multi-chirp waveforms, particularly orthogonal chirp division multiplexing (OCDM) and affine frequency division multiplexing (AFDM), have been identified as promising candidates for 6G communications. OCDM uses the Discrete Fresnel Transform (DFT), while AFDM is based on the Discrete Affine Fourier Transform (DAFT), incorporating the DFT as a special case. In particular, AFDM is renowned for its ability to utilize the diversity properties of linear time-varying channels while maintaining minimal pilot signal overhead.

[0005] A key feature of AFDM is its use of chirped pilots for efficient channel estimation, a significant departure from pilots in long-term evolution (LTE) and new-radio (NR) systems. These pilots provide a complete delay-Doppler channel representation, crucial for extracting accurate range-velocity target information in sensing and radar applications.

[0006] Nevertheless, AFDM still faces a significant challenge: the bandwidth occupied by its chirped signal spans the entire bandwidth from –fs / 2 to fs / 2, where fs represents the sampling rate. This limits the flexibility in adjusting the signal bandwidth, thus posing a practical challenge to implementing AFDM within the 6GISAC framework. Summary of the Invention

[0007] To address these challenges, this disclosure proposes a novel method for designing AFDM pilot generation schemes. This method aims to achieve flexible spectrum shaping of AFDM-based pilots without altering the sampling rate of the digital-to-analog converter (DAC). The proposed scheme is expected to enhance the applicability and performance of AFDM technology in various communication and sensing scenarios within the 6G ISAC space, thereby filling a key gap in current technology.

[0008] These and other objectives are achieved by means of the solutions provided in this disclosure as set forth in the appended independent claims. Advantageous implementations are further defined in the dependent claims.

[0009] The first aspect of this disclosure provides a network entity for generating chirped pilot signals, for: obtaining a first parameter set from a core network device, wherein the first parameter set includes: the number of pilot sequences to be generated ( N The time-domain chirp rate of the pilot sequence to be generated ( c 1) and the frequency domain chirp rate of the pilot sequence to be generated ( c 2), among which, N It is a positive integer; obtained based on the first parameter set. N A pilot sequence, wherein each pilot sequence includes K A set of pilot chirped carrier samples, K Not less than N An integer; for each antenna port of the network entity, determine the... N A subset of pilot sequences, and based on the newly formed K A set of samples is used to synthesize the pilot signal to be transmitted from the antenna port. K Each of the samples is obtained by analyzing the... N The pilot sequences in the determined subset of the pilot sequences K It is obtained by summing the corresponding samples in a sample.

[0010] This disclosure proposes an AFDM pilot generation scheme to meet any spectral masking requirements without changing the DAC's sampling rate. The bandwidth specified for sensing and channel estimation using the pilot signal can be configured to any selected value not exceeding the sampling rate. The architecture for pilot signal generation and detection employs an inherently simple design, facilitating implementation and improving operational efficiency without compromising system performance.

[0011] It is understandable that "pilot sequence" is N One of the pilot chirped carriers. When transmitting a pilot signal through one of the antenna ports, the transmitted signal can be a single pilot sequence or a composite signal formed by summing a selected set of these sequences. In practice, the selected subset of sequences does not cover the entire set, as many chirped carriers within the set are intentionally left blank, forming a "pilot guard interval" to mitigate interference. Furthermore, the composition of this subset may vary between different antenna ports, supporting customized transmission strategies to optimize spectrum resource utilization and enhance the robustness of the channel estimation process.

[0012] In one implementation of the first aspect, the formation of the K A new set of samples, the K Each of the samples is obtained by analyzing the... N The pilot sequences in the determined subset of the pilot sequences K The summation of corresponding samples in a sample set is obtained, including: for each pilot sequence, the summation of the corresponding samples in the sample set. K Weights are applied to each sample in each pilot chirped carrier sample to produce K A weighted pilot chirped carrier sample, wherein the pilot signal of the... K Each sample in the new set of samples is obtained by... N The pilot sequences in the determined subset of the pilot sequences K It is formed by summing the corresponding weighted pilot chirped carrier samples in each sample.

[0013] Optionally, before summing the corresponding pilot chirped carrier samples, a weighting function can be applied to the samples, and the weighted pilot chirped carrier samples are summed to form a sample of the pilot signal.

[0014] In one implementation of the first aspect, the network entity is used to: obtain based on the first parameter set and the second parameter set. N A set of pilot sequences, wherein the second parameter set includes the bandwidth of the pilot sequences to be generated and the parameters used to obtain each pilot sequence to be generated. K The sampling period of a set of pilot chirped carrier samples ( T s).

[0015] In generating pilot sequences, it may be necessary to use additional parameters from the pilot codebook beyond the primary parameters initially considered. For example, the bandwidth or sampling period of the pilot sequence to be generated may be taken into account.

[0016] In one implementation of the first aspect, the network entity is used to: determine a continuous-time chirped carrier function based on a discrete-time pilot chirped carrier, wherein the discrete-time pilot chirped carrier is parameterized using the first parameter set; by using a sampling rate of 1 / T The continuous-time chirped carrier function is sampled to obtain a set of pilot chirped carrier samples.

[0017] This method involves N Point AFDM pilot signal is defined as corresponding to discrete time N Point AFDM pilot carrier Continuous time version The sum of .

[0018] In one implementation of the first aspect, the second parameter set further includes a continuous-time chirped carrier function type, wherein when the continuous-time chirped carrier function type is a first type, the network entity is used to determine the continuous-time chirped carrier function based on the discrete-time pilot chirped carrier using a complex exponential function, wherein the instantaneous frequency of the complex exponential function is a specific step function of the chirped carrier; when the continuous-time chirped carrier function type is a second type, the network entity is used to determine the continuous-time chirped carrier function by applying an interpolation formula to samples of the discrete-time pilot chirped carrier.

[0019] In particular, this disclosure proposes a continuous-time function. There are two possible formulas. One is a formula for an exact analog chirped version of the discrete-time AFDM chirped carrier, and the other is a formula using discrete time... AFDM chirped carrier Point DFT coefficients, for this discrete time Formula for interpolating samples of a point AFDM chirped carrier.

[0020] In one implementation of the first aspect, the network entity is used to: obtain the network entity based on a lookup table, using the first parameter set and the second parameter set. K A set of pilot chirped carrier samples.

[0021] In one implementation of the first aspect, the network entity is configured to: obtain a reference pilot chirped carrier from a lookup table using the first parameter set and the second parameter set, wherein the lookup table is a reduced-size lookup table; generate a sequence of pilot chirped carrier samples by cyclically shifting the reference pilot chirped carrier; and from the... K The pilot chirped carrier is obtained from the sequence of pilot chirped carrier samples. K A set of pilot chirped carrier samples.

[0022] In addition to using the above formula to calculate samples online, another way is to retrieve the required samples from a lookup table calculated "offline" with different combinations of pilot parameters.

[0023] In one implementation of the first aspect, the network entity is used to: shift the synthesized pilot signal to a predefined frequency by applying a linear phase shift to the acquired N pilot sequences.

[0024] It is possible to shift the frequency of the pilot sequence, for example, for frequency domain multiplexing of AFDM pilot signals and OFDM.

[0025] In one implementation of the first aspect, the second parameter set further includes a window function type and one or more window parameters corresponding to the window function type.

[0026] In one implementation of the first aspect, the network entity is used to: [operate based on the first parameter set, the second parameter set, and...] m The value of the above N The first pilot sequence in the nth pilot sequence m The pilot sequence K A window function is applied to each pilot chirped carrier sample to perform pulse shaping on the m-th pilot sequence, where m is the... N The index of the pilot sequence in the pilot sequence.

[0027] Alternatively, pulse shaping can be applied to AFDM chirp to address both fractional delay and fractional Doppler, and to reduce out-of-band emission (OOBE) levels.

[0028] In one implementation of the first aspect, the window function type includes a global window function type and / or a segmented window function type, wherein the network entity is further configured to: when the window function type is the global window function type, perform operations on the... K A global window function is applied to each pilot chirped carrier sample in the pilot chirped carrier samples, and / or when the window function type is the segmented window function type, the global window function is applied to each pilot chirped carrier sample in the pilot chirped carrier samples. KThe segmented window function is applied to each pilot chirped carrier sample within a chirped segment of a pilot chirped carrier sample.

[0029] It should be noted that, in order to mitigate leakage in the channel caused by fractional Doppler frequency shift, "global" pulse shaping can be applied, that is, pulse shaping applied to the entire AFDM symbol. For pulse shaping that causes a sharp transition decay around the time instance, a window function of the pulse shape can be applied segmentally.

[0030] In one implementation of the first aspect, the network entity is configured to: add sample prefixes and / or sample suffixes to the K pilot chirped carrier samples of the pilot signal, wherein the sample prefix includes one of the following: a chirped periodic prefix, a periodic prefix, or a zero-value prefix, and / or the sample suffix includes one of the following: a chirped periodic suffix, a periodic suffix, or a zero-value suffix.

[0031] Optionally, a duration of [duration] can be generated. The prefix of seconds and / or duration is Pilot signal with a suffix of seconds.

[0032] In one implementation of the first aspect, the network entity is implemented in a terminal device, wherein the network entity is further configured to: obtain the second parameter set from a radio access network (RAN) device, wherein the first parameter set is received from the core network device via the RAN device.

[0033] In one particular embodiment, the network entity may be an ISAC terminal. The ISAC terminal obtains a first set of parameters and a second set of parameters from the RAN device.

[0034] In one implementation of the first aspect, the network entity is implemented in a RAN device, wherein the network entity is further used to determine the second set of parameters.

[0035] In another embodiment, the network entity may be a RAN device, and the second set of parameters may be determined by the RAN device.

[0036] A second aspect of this disclosure provides a core network device for: providing a first set of parameters to one or more network entities for generating chirped pilot sequences, wherein the first set of parameters includes: the number of pilot sequences to be generated ( N The time-domain chirp rate of the pilot sequence to be generated ( c 1) and the frequency domain chirp rate of the pilot sequence to be generated ( c 2), among which, N It is a positive integer.

[0037] This disclosure also proposes a core network device for providing network entities with the parameters required for generating chirped pilot signals.

[0038] In one implementation of the second aspect, the time-domain chirp rate allocated to different network entities ( c 1) Selected to have different values.

[0039] parameter c 1 represents a cell-specific parameter. The network assigns different parameters to different cells (i.e., different network entities). c A value of 1 is used to reduce inter-cell pilot interference.

[0040] A third aspect of this disclosure provides a RAN device for forwarding a first set of parameters received from a core network device to one or more network entities for chirp-based pilot sequence generation, wherein the first set of parameters includes: the number of pilot sequences to be generated ( N The time-domain chirp rate of the pilot sequence to be generated ( c 1) and the frequency domain chirp rate of the pilot sequence to be generated ( c 2), among which, N The parameter is a positive integer; a second parameter set is provided to the one or more network entities, wherein the second parameter set includes the bandwidth of the pilot sequence to be generated, and the sampling period for obtaining the pilot chirped carrier sample set for each pilot sequence to be generated. T s), and continuous-time chirped carrier function type.

[0041] This disclosure also proposes a RAN device for providing network entities with the parameters required for generating chirped pilot signals.

[0042] In one implementation of the third aspect, the second parameter set further includes a window function type and one or more window parameters corresponding to the window function type, wherein the window function type includes a global window function type and / or a segmented window function type.

[0043] A fourth aspect of this disclosure provides a method for generating chirped pilot sequences performed by a network entity, the method comprising: obtaining a first set of parameters from a core network device, wherein the first set of parameters includes: the number of pilot sequences to be generated. N The time-domain chirp rate of the pilot sequence to be generated ( c 1) and the frequency domain chirp rate of the pilot sequence to be generated ( c 2), among which, N It is a positive integer; obtained based on the first parameter set. N A pilot sequence, wherein each pilot sequence includesK A set of pilot chirped carrier samples, K Not less than N Integers; for the N Weights are applied to each set of pilot carrier samples to produce N A weighted set of pilot carrier samples; for each antenna port of the network entity, determine the... N A subset of pilot sequences; based on the newly formed K A set of samples is used to synthesize the pilot signal to be transmitted from the antenna port. K Each of the samples is obtained by analyzing the... N The pilot sequences in the determined subset of the pilot sequences K It is obtained by summing the corresponding samples in a sample.

[0044] In one implementation of the fourth aspect, the method includes: for each pilot sequence, for the... K Weights are applied to each sample in each pilot chirped carrier sample to produce K A weighted pilot chirped carrier sample, wherein the pilot signal of the... K Each of the samples is obtained by analyzing the... N The pilot sequences in the determined subset of the pilot sequences K It is formed by summing the corresponding weighted pilot chirped carrier samples in each sample.

[0045] In one implementation of the fourth aspect, the method includes: obtaining based on the first parameter set and the second parameter set. N A set of pilot sequences, wherein the second parameter set includes the bandwidth of the pilot sequence to be generated and the sampling period for obtaining the pilot chirped carrier sample set for each pilot sequence to be generated. T s).

[0046] In one implementation of the fourth aspect, the method includes: determining a continuous-time chirped carrier function based on a discrete-time pilot chirped carrier, wherein the discrete-time pilot chirped carrier is parameterized using the first parameter set; and by using a sampling rate of 1 / T The continuous-time chirped carrier function is sampled to obtain a set of pilot chirped carrier samples.

[0047] The implementation of the fourth aspect can correspond to the implementation of the network entity in the first aspect described above. The fourth aspect and its implementation achieve the same advantages and effects as those described above for the network entity in the first aspect and its implementation.

[0048] A fifth aspect of this disclosure provides a method performed by a core network device, the method comprising: providing a first set of parameters to one or more network entities for generating chirped pilot sequences, wherein the first set of parameters includes: a number of pilot sequences to be generated ( N The time-domain chirp rate of the pilot sequence to be generated ( c 1) and the frequency domain chirp rate of the pilot sequence to be generated ( c 2), among which, N It is a positive integer.

[0049] The implementation of the method in the fifth aspect can correspond to the implementation of the core network equipment in the second aspect described above. The fifth aspect and its implementation achieve the same advantages and effects as those described above for the core network equipment in the second aspect and its implementation.

[0050] A sixth aspect of this disclosure provides a method performed by a RAN device, the method comprising: forwarding a first set of parameters received from a core network device to one or more network entities for chirp-based pilot sequence generation, wherein the first set of parameters includes: a number of pilot sequences to be generated ( N The time-domain chirp rate of the pilot sequence to be generated ( c 1) and the frequency domain chirp rate of the pilot sequence to be generated ( c 2), among which, N The parameter is a positive integer; a second parameter set is provided to the one or more network entities, wherein the second parameter set includes the bandwidth of the pilot sequence to be generated, and the sampling period for obtaining the pilot carrier sample set for each pilot sequence to be generated. T s), and continuous-time chirped carrier function type.

[0051] The implementation of the method in the sixth aspect can correspond to the implementation of the RAN device in the third aspect described above. The method in the sixth aspect and its implementation achieves the same advantages and effects as those described above for the RAN device in the third aspect and its implementation.

[0052] The seventh aspect of this disclosure provides a computer program product including program code that, when executed by a processor, causes the processor to perform the method according to the third aspect and any implementation thereof or the fourth aspect and any implementation thereof.

[0053] A sixth aspect of this disclosure provides a computer-readable medium including instructions that, when executed by a computer, cause the computer to perform the fourth aspect and any implementation thereof, the method according to the fifth aspect and any implementation thereof, or the method according to the sixth aspect and any implementation thereof.

[0054] It should be noted that all devices, elements, units, and modules described in this application can be implemented in software or hardware elements or any combination thereof. All steps performed by the various entities described in this application, and the functions to be performed by the various entities described, are intended to indicate that the respective entities are suitable for or used to perform the respective steps and functions. Although in the following description of specific embodiments, a particular function or step performed by an external entity is not reflected in the detailed description of the specific element of the entity performing that particular step or function, it should be apparent to those skilled in the art that these methods and functions can be implemented in the corresponding software or hardware elements or any combination thereof. Attached Figure Description

[0055] The following description of specific embodiments, in conjunction with the accompanying drawings, illustrates various aspects and implementations of the present disclosure, wherein: Figure 1 The network entities provided in embodiments of this disclosure are illustrated; Figure 2 The time-frequency representation of two DAFT symbols is shown; Figure 3 The generation of oversampled chirped pilots provided in embodiments of this disclosure is illustrated; Figure 4 A general block diagram of the proposed system provided by embodiments of the present disclosure is shown; Figure 5 A general block diagram of a network entity provided in an embodiment of this disclosure is shown; Figure 6 The continuous-time version obtained by type 1 functions and type 2 functions, as provided in embodiments of this disclosure, is illustrated. The real part and the 0th discrete-time chirped carrier sample The real part; Figure 7 The frequency shift of the oversampled chirped pilot provided in embodiments of this disclosure is illustrated; Figure 8 Pulse shaping of AFDM chirps provided by embodiments of this disclosure is illustrated; Figure 9 The core network device provided in an embodiment of this disclosure is shown; Figure 10 An embodiment of the RAN device provided in this disclosure is shown; Figure 11The method provided by embodiments of this disclosure is illustrated; Figure 12 The method provided by embodiments of this disclosure is illustrated; Figure 13 The method provided by embodiments of this disclosure is illustrated. Detailed Implementation

[0056] The following description, in conjunction with the accompanying drawings, provides illustrative embodiments of network entities, core network devices, RANs, and corresponding methods for generating chirped pilot signals. While this description provides detailed examples of possible implementations, it should be noted that these details are intended to be exemplary and do not limit the scope of this application.

[0057] Furthermore, one embodiment or example may refer to multiple other embodiments or examples. For instance, any descriptions mentioned in one embodiment or example, including but not limited to terms, elements, processes, explanations, and / or technical advantages, may also be applicable to multiple other embodiments or examples.

[0058] Figure 1 A network entity 100 for generating chirped pilot signals is shown, according to an embodiment of the present disclosure.

[0059] Network entity 100 may include processing circuitry (not shown) for performing, implementing, or initiating various operations of network entity 100 as described herein. The processing circuitry may include hardware and software. Hardware may include analog circuitry, digital circuitry, or both. Digital circuitry may include components such as application-specific integrated circuits (ASICs), field-programmable arrays (FPGAs), digital signal processors (DSPs), or multi-purpose processors. Network entity 100 may also include memory circuitry storing one or more instructions that can be executed by a processor or processing circuitry (specifically, under software control). For example, the memory circuitry may include a non-transitory storage medium storing executable software code that, when executed by a processor or processing circuitry, causes network entity 100 to perform various operations. In one embodiment, the processing circuitry includes one or more processors and non-transitory memory connected to one or more processors. The non-transitory memory may carry executable program code that, when executed by one or more processors, causes network entity 100 to perform, implement, or initiate the operations or methods described herein.

[0060] Network entity 100 is used to obtain a first parameter set 101 from core network device 200. The first parameter set 101 includes: the number of pilot sequences to be generated ( N ), the time-domain chirp rate of the pilot sequence to be generated ( ) and the frequency domain chirp rate of the pilot sequence to be generated ( ),in, N It is a positive integer. Network entity 100 is also used to obtain based on the first parameter set 101. N A pilot sequence 102, wherein each pilot sequence 102 includes K A set of pilot chirped carrier samples, K Not less than N The integer. Then, network entity 100 is used to: for each antenna port of network entity 100, determine N A subset of pilot sequences 102. Network entity 100 is also used for: based on the newly formed... K A set of samples is used to synthesize the pilot signal 103 to be transmitted from the antenna port. Each sample is obtained by... N Each pilot sequence in a defined subset of pilot sequences 102 K It is obtained by summing the corresponding samples in a sample.

[0061] The purpose of this disclosure is to address the aforementioned challenges by designing an AFDM pilot generation scheme to meet any spectral masking requirements without changing the DAC's sampling rate. The scheme proposed in this disclosure aims to provide flexible spectral shaping based on AFDM pilots, and has the following characteristics: 1. The bandwidth specified for sensing and channel estimation using pilot signals can be configured to any selected value not exceeding the sampling rate. Conversely, the sampling rate can be set to any value exceeding the nominal bandwidth of the pilot signal, thus providing great versatility in bandwidth utilization.

[0062] 2. The architecture used for pilot signal generation and detection adopts an inherently simple design, which facilitates implementation and improves operating efficiency without compromising system performance.

[0063] 3. This design ensures the generation of pilot signals with a low peak-to-average power ratio (PAPR), thereby reducing power requirements and enhancing the signal's resistance to nonlinear distortion. Furthermore, the pilot signal exhibits minimal leakage, which contributes to improved accuracy in delay-Doppler detection and estimation, crucial for robust and reliable sensing across various operating environments.

[0064] This disclosure fills a key gap in AFDM technology within the 6G ISAC field, providing a solution to enhance its applicability and performance in various communication and sensing scenarios. It is understood that the network entity 100 generating the chirped pilot signal 103 can be any network device, such as an advanced base station, edge computing node, or backhaul network device equipped with ISAC capabilities, or any ISAC terminal device, such as connected vehicles, smartphones, smart home devices, wearable ISAC devices, industrial ISAC sensors, etc.

[0065] To facilitate understanding of this application, the AFDM signal is first introduced here. Figure 2 The principle of AFDM signal structure is illustrated. AFDM utilizes DAFT for signal construction. DAFT is a method based on parameters (…). The linear transformation represented by ) belongs to a more general form, which includes the discrete Fresnel transform (DFnT) as a special case.

[0066] In AFDM, the transmitter applies the inverse discrete affine Fourier transform (IDAFT) to map the input symbols onto discrete-time chirps. These chirps are generated through (…). The parameters are parameterized as shown in the figure, where the frequency shift of each chirp can be determined by a ratio. Confirmed, among which m Indicates the chirping index. N Δ t This indicates the duration of the symbol. In AFDM, the role of IDAFT is similar to that of the inverse discrete Fourier transform (IDFT) in OFDM, where the input symbols are mapped to frequency subcarriers.

[0067] The upper half of the figure shows a typical AFDM signal without a cyclic prefix or suffix, while the lower half shows a signal including these cyclic extensions. A cyclic prefix is ​​added to each symbol ( T prefix ) and suffix ( T suffix This is to reduce inter-symbol interference and facilitate better synchronization in multipath channels. Therefore, the total duration of an AFDM symbol becomes... T + T prefix + T suffix ,in, T It is the duration of the original symbol. N Δ t.

[0068] The bandwidth of the AFDM signal (expressed as 1 / Δ) t This remains constant across each chirp to ensure efficient use of the entire bandwidth. This is crucial for 6G applications that require high spectral efficiency.

[0069] AFDM, by leveraging the diversity characteristics of linear time-varying (LTV) channels while maintaining low pilot signal overhead, has become a promising candidate for future wireless communication systems. The architecture of AFDM ensures robust performance under various channel conditions, making it particularly suitable for the complex environments anticipated in 6G networks.

[0070] When multiplexing and communication in the time or frequency domains, instead of employing the highly complex method of spectral shaping of AFDM signals through frequency domain resampling, a more efficient and less complex scheme is used. This method involves... point -AFDM pilot signal is defined as corresponding to discrete time Point AFDM pilot carrier Continuous time version The sum of . Therefore, by (at most) indivual Signal composed of point AFDM pilots It can be generated using the following equation:

[0071] Among them, superscript ' 'Represents "continuous time" It is the weighted number The complex values ​​of the pilot frequencies. The resulting... ( It will have bandwidth independent of the sampling rate, solely determined by... and The relationship between them determines this. Therefore, ( ) can be done by taking samples (For some integer values) Feed to meet sampling rate The DAC runs for (seconds) to synthesize, where, , It is the bandwidth of the signal, such as Figure 3 As shown, this provides an efficient method for generating AFDM signals.

[0072] According to one embodiment of this disclosure, when the pilot signal 103 is formed... KWhen creating a new set of samples, network entity 100 can be used for: for samples with an index Each pilot sequence 102, for K Weights are applied to each sample in the pilot chirped carrier sample. To produce K A weighted pilot chirped carrier sample, pilot signal 103 K Each sample in the new set of samples is obtained through... N Each pilot sequence 102 in a defined subset of pilot sequences 102 K It is formed by summing the corresponding weighted pilot chirped carrier samples in each sample.

[0073] To generate pilot signals without prefixes or suffixes (or with zero-value prefixes and suffixes), simply sample... Feeded to the DAC, thus generating a length of A pilot signal for seconds.

[0074] If you want to generate a file with a duration of... The prefix and duration of seconds are Pilot signals with a suffix of seconds, then samples ,in, and ,in,' ' represents a rounding function, such as round down, round up, or round to the nearest integer. This will generate a time of... The pilot signal occupies the interval ,like Figure 2 As shown.

[0075] According to one embodiment of this disclosure, the network entity can be used for pilot signal 103. K Each pilot chirped carrier sample is given a sample prefix and / or a sample suffix. It should be noted that the sample prefix includes one of the following: a chirped periodic prefix, a periodic prefix, or a zero-value prefix, and / or the sample suffix includes one of the following: a chirped periodic suffix, a periodic suffix, or a zero-value suffix.

[0076] Figure 4 A wireless communication system provided by an embodiment of this disclosure is illustrated. The system includes multiple network devices, including at least one core network node 200, at least one network node 300, and multiple network entities 100 capable of communication and sensing, namely ISAC terminals. The network devices themselves may have integrated communication and sensing capabilities. The core network node 200 is used to allocate cell-specific pilot parameters (most importantly, the parameters) to different network devices. N and The value needs to be coordinated between adjacent cells to keep inter-cell pilot interference at a low level. It should be noted that each ISAC terminal can be... Figure 1 The network entity 100 is shown. The network entity 100 can obtain a first parameter set 101 and an additional second parameter set 104 from a network node (e.g., RAN device 300). In particular, the first parameter set 101 is received from the core network device 200 via the RAN device 300.

[0077] It is worth noting that, in different embodiments of this disclosure, network entity 100 can be implemented in RAN device 300. In this case, network entity 100 is used to obtain a first parameter set 101 from the core network device, and network entity 100 can also be used to determine a second parameter set 104.

[0078] According to one embodiment of this disclosure, network entity 100 can be used to obtain N pilot sequences 102 based on a first parameter set 101 and a second parameter set 104, wherein the second parameter set 104 includes the bandwidth of the pilot sequences to be generated ( ) and used to obtain each pilot sequence to be generated K The sampling period of a set of pilot chirped carrier samples ( ).

[0079] Figure 5 A block diagram of a transmitter in a network entity 100 provided in an embodiment of the present disclosure is shown. In this particular embodiment, network entity 100 includes a sequence generator block responsible for generating pilot sequences.

[0080] The analog-to-digital converter (ADC) box is connected to two pilot signal generators. It digitizes the analog pilot signals generated by the pilot signal generators, thereby converting these signals into a digital format that can be processed or transmitted by a digital system.

[0081] The antenna subsystem is connected to the ADC and is responsible for transmitting the digitized pilot signal through the antenna. This antenna subsystem includes multiple transmit antennas.

[0082] The pilot parameter allocation signaling indicates the path of control signals sent to each box within network entity 100 for parameter allocation. It ensures that the pilot signals are generated using the correct settings.

[0083] Sequence generator At the sequence generator box of network entity 100, the sample It can be calculated online when needed, or stored in a lookup table for different combinations of pilot codebook parameters.

[0084] This disclosure proposes two types of continuous-time chirped carrier functions for online generation of continuous-time versions. .

[0085] For the first type, network entity 100 uses a complex exponential function to determine the continuous-time chirped carrier function based on a discrete-time pilot chirped carrier, wherein the instantaneous frequency of the complex exponential function is a specific step function of the chirped carrier.

[0086] Specifically, the continuous-time version of the upsampled chirped pilot is used. Based on The following is a precise simulation of the chirp version defined by:

[0087] Here, It is a step function This indicates that the bandwidth of the pilot signal is limited to... The effects of the required spectral folding on the discontinuities in the instantaneous frequency of the simulated chirp. These discontinuities occur at time instances. ( ),

[0088] in, .

[0089] For the second type, network entity 100 is used to determine the continuous-time chirped carrier function by applying an interpolation formula to samples of discrete-time pilot chirped carriers.

[0090] In particular, discrete-time chirping The continuous-time version uses its DFT coefficients. Interpolate its samples as follows:

[0091] Figure 6 This shows the results obtained through type 1 and type 2 functions. The real part and the 0th discrete-time chirped carrier sample Examples of the real part.

[0092] It can be understood that one possible continuous-time chirp formula for generating the upsampled discrete-time chirped pilot is the exact analog chirped version of the discrete-time AFDM chirped carrier (Type 1). Another possible continuous-time formula is the discrete-time... Samples of point AFDM chirped carriers use their Interpolation formula for point DFT coefficients (Type 2).

[0093] Considering the prefix and suffix of the pilot signal, one possible way to sample the formula is to calculate the above "online" according to the formula. One sample.

[0094] Another approach is to retrieve the required parameters from a lookup table calculated "offline" using different combinations of pilot parameters. One sample.

[0095] According to another embodiment of this disclosure, network entity 100 can be used to obtain, based on a lookup table, a first parameter set 101 and a second parameter set 104. K A set of pilot chirped carrier samples.

[0096] Optionally, network entity 100 can be used to obtain a reference pilot chirped carrier from a lookup table using a first parameter set 101 and a second parameter set 104, wherein the lookup table is a reduced-size lookup table. Network entity 100 can be used to: generate a sequence of pilot chirped carrier samples by cyclically shifting the reference pilot chirped carrier; from K The pilot chirped carrier is obtained from the sequence of pilot chirped carrier samples. K A set of pilot chirped carrier samples.

[0097] AFDM Chirped Pilot Codebook: Look-up Table (LUT) and Circular Shift To reduce computing costs and memory storage requirements, one can... generate ,in, yes A small subset of. For example, when It is an even number and When the number is odd, all chirps can be calculated by cyclically shifting one of the chirps, i.e. .

[0098] More precisely, consider referencing chirping as Chirping (when It is an even number and When the number is odd, it can be obtained as follows: Search Make and .

[0099] when and When the reference chirped carriers are not coprime, it is no longer possible to generate all chirped carriers from a single reference chirped carrier. Instead, the cardinality of the reference chirped subset becomes greater than 1: However, this cardinality still satisfies... And for and The actual value, even In other words, for and Given a value, the AFDM pilot codebook size is not the same as Proportional, but with and The greatest common divisor ( It is directly proportional to. And if The number of subcarriers must be even (as in the case of the number of subcarriers allocated in OFDM) and If the restriction is that the number must be odd (this is not a restriction), then for and The pilot codebook size for the given value will be equal to 1, and the total pilot codebook size will be equal to ( (Number of possible values) × ( (The number of possible values).

[0100] In the NR 5G system specification, tuples A maximum of 20 different configurations were defined, among which, This indicates the magnitude of the Fast Fourier Transform (FFT). It is the sampling period. Therefore, The number of feasible values ​​is expected to be within this defined range. Furthermore, parameters exceeding the maximum Doppler spread expressed in sample size are selected. It should only be slightly larger than this spread to maintain system efficiency. Doppler spread indicates the rate of frequency change caused by the relative motion between the transmitter and receiver. In most practical scenarios, Doppler spread is typically... The smallest fraction of .

[0101] Taking these factors into account, the total number of unique entries in the pilot codebook used for efficient transmission of pilot signals is estimated to be no more than a few thousand. This estimate assumes that the FFT size is comparable to that used in existing 5G NR systems. This codebook size helps to maintain a balance between system complexity and the flexibility required to adapt to different channel conditions and operational requirements.

[0102] AFDM pilot multi-cell allocation parameter These parameters are cell-specific. The network assigns different values ​​of these parameters to different cells, i.e., to different base stations or network devices, to reduce inter-cell pilot interference. Consider the network assigning these values ​​to two adjacent cells. N The case where the values ​​are the same. Under this condition, for the case where two different parameter values ​​are used. (Right now and Synthesized of the same lengthN Examining the cross-correlation characteristics of the AFDM pilot chirps reveals a noteworthy feature. Specifically, when and When coprime, the absolute value of the cross-correlation between these pilot chirps is equal to When this condition is not met, the absolute value of the cross-correlation is either 0 or... ,in,' ' represents the "greatest common divisor". This relationship emphasizes the ability to maintain the orthogonality between pilot signals from neighboring cells, which is a key factor in reducing inter-cell interference and ensuring the integrity of sensing and communication functions in dense network deployments.

[0103] Frequency domain multiplexing of AFDM pilot signals with other waveforms Pilot signals can be multiplexed in the frequency domain with other signals that may have different waveforms, for example, within an OFDM-based frame structure in a wireless system. This can be achieved by applying a linear phase shift to the pilot samples generated using the disclosed method to center the signal at a given frequency in the subband. The operation is as follows: Figure 7 As shown, the center frequency (normalized relative to the subcarrier spacing) is expressed as... . Figure 7 This demonstrates shifting the oversampled chirped pilot frequency to... (The center of the ISAC band).

[0104] According to this embodiment of the present disclosure, network entity 100 is also used to shift the synthesized pilot signal 103 to a predefined frequency by applying a linear phase shift to the acquired N pilot sequences 102.

[0105] Pulse shaping of the AFDM chirp is performed to address both fractional delay and fractional Doppler and to reduce out-of-band emission (OOBE) levels. Recall that the continuous-time version of the chirped pilot used to generate the upsampled signal... When defined as follows , In its instantaneous frequency function, there will be a time instance ( There is a discontinuity at this point.

[0106]

[0107] This is because spectral folding is required to limit the bandwidth of the pilot signal. Here, This represents the effects of these discontinuities. Even when using a DFT-based interpolated signal as a continuous-time version of the AFDM discrete-time carrier, i.e., (in for (DFT coefficients) The signal will still occur in time instances. The surrounding area experiences abrupt transitions. These discontinuities or abrupt transitions are significant in the presence of fractional delay offsets and can lead to leakage in the channel DAFT domain response.

[0108] Both types of continuous-time chirps require pulse shaping for attenuation. The surrounding transitions are abrupt. This can be achieved by applying a window function with a pulse shape to each segment. The first chirped carrier indivual Chirping Segmentation (For a certain () is defined as two subsequent discontinuities. and The interval between. Let. Specify the window type that defines the shape of each segmented pulse (subscript " “ represents a segment”. For example, You can specify a Dolph-Chebyshev or raised cosine window. Additionally, set... A tuple representing the parameters of this window. For example, when When it is Dorf-Chebyshev, tuple It's just a parameter pair: window base length ( The Dolph-Chebyshev attenuation level (in dB) is also mentioned. It should be noted that this means the pulse shape differs between the chirped pilots: it is cyclically shifted. More precisely, the chirp... and The pulse shape is shifted relative to each other by an amount equal to [missing value] in continuous time. Time shift. To simplify the expression, assume... It is an integer that is divisible by 0. ,and Divisible And both the prefix and suffix are zero. In this case, the first... A window sequence of chirped carriers Written The basic length is The concatenation of window sequences, each window sequence is represented as ,Right now As for ( ), it is made of Given, among which, Representative model Calculation.

[0109] Furthermore, to mitigate leakage in the channel caused by fractional Doppler frequency shift, "global" pulse shaping is still required, i.e., pulse shape applied to the entire AFDM symbol, such as... Figure 8 As shown. The reason is that, in and Between (in the case of no prefix and suffix or with zero-value prefix and suffix) or and Continuous-time chirp functions between (in the case of adding prefixes and suffixes to AFDM symbols) There is a potential discontinuity in the instantaneous phase, not the instantaneous frequency. This discontinuity needs to be attenuated through a window of the symbol range. (subscript) The '' character represents the "global" window type used to indicate this pulse shape. For example, This can represent a Dolph-Chebyshev or raised cosine window. Furthermore, let... A tuple representing the parameters of this window. For example, in In the case of Dolph-Chebyshev, tuple It's just a pair of parameters: window length (when the global pulse shape is applied to a basic AFDM symbol that does not contain its prefix and suffix, for Otherwise ) and Dolph-Chebyshev attenuation level (in dB). The sequence representing the global pulse shape is the first... Each sample can be specified as A useful side effect of the disclosed pulse shaping for responding to fractional delay and Doppler shift is a significant reduction in the OOBE level of perceived chirp.

[0110] It should be noted that, when applying both segmented and global pulse shaping, the first... The total window for each AFDM chirped carrier is Therefore, the first The first pilot sequence The sample is .

[0111] Figure 9 A core network device 200 provided in an embodiment of this disclosure is illustrated. The core network device 200 is configured to provide a first parameter set 101 to one or more network entities 100 for chirp-based pilot sequence generation, wherein the first parameter set 101 includes: the number of pilot sequences to be generated (…). N), the time-domain chirp rate of the pilot sequence to be generated ( ) and the frequency domain chirp rate of the pilot sequence to be generated ( ), where N is a positive integer.

[0112] In one implementation, network entity 100 can be Figure 1 , Figure 4 or Figure 5 The network entity shown. Core network device 200 can be... Figure 1 or Figure 4 The core network device 200 is shown.

[0113] Optionally, the time-domain chirp rate assigned to different network entities 100 ( The parameter is selected to have different values. As discussed in the previous examples, the parameter... It is specific to the cell. The network assigns different [configurations] to different cells (i.e., different network entities 100). The value is adjusted to reduce inter-cell pilot interference.

[0114] Figure 10 An embodiment of the RAN device 300 provided in this disclosure is illustrated. The RAN device 300 is used to forward a first parameter set 101 received from the core network device 200 to one or more network entities 100 for chirp-based pilot sequence generation, wherein the first parameter set 101 includes: the number of pilot sequences to be generated (…). N ), the time-domain chirp rate of the pilot sequence to be generated ( ) and the frequency domain chirp rate of the pilot sequence to be generated ( ), where N is a positive integer. RAN device 300 is also used to provide a second parameter set 104 to one or more network entities 100, wherein the second parameter set 104 includes the bandwidth of the pilot sequence to be generated ( The sampling period used to obtain the pilot chirped carrier sample set for each pilot sequence to be generated ( ), and continuous-time chirped carrier function type.

[0115] In one implementation, network entity 100 can be Figure 1 or Figure 4 The network entity shown. Core network device 200 can be... Figure 1 or Figure 4 The core network device 200 is shown. The RAN device 300 can be... Figure 4 The RAN device 300 shown.

[0116] Optionally, the second parameter set 104 also includes a window function type and one or more window parameters corresponding to the window function type, wherein the window function type includes a global window function type and / or a segmented window function type.

[0117] In one particular embodiment, RAN device 300 may also be network entity 100. In this case, RAN device determines a second parameter set 104 and generates a chirp-based pilot signal based on the first parameter set 101 and the second parameter set 104.

[0118] Figure 11 The present disclosure illustrates a method 1100 provided by embodiments thereof, particularly for chirp-based pilot sequence generation. In one particular embodiment, method 1500 is performed by... Figure 1 , Figure 4 , Figure 5 , Figure 9 or Figure 10 The method is executed by one of the network entities 100 shown. Method 1100 includes step 1101: obtaining a first parameter set 101 from core network device 200, wherein the first parameter set 101 includes: the number of pilot sequences to be generated (…). N ), the time-domain chirp rate of the pilot sequence to be generated ( ) and the frequency domain chirp rate of the pilot sequence to be generated ( ),in, N It is a positive integer. Furthermore, method 1100 includes step 1102: obtaining based on the first parameter set 101. N A pilot sequence 102, wherein each pilot sequence 102 includes K A set of pilot chirped carrier samples, K Not less than N The method 1100 also includes step 1103: for each antenna port of network entity 100, determining a subset of N pilot sequences 102; and step 1104: based on the formed new K A set of samples is used to synthesize the pilot signal 103 to be transmitted from the antenna port. K Each of the samples is obtained through... N Each pilot sequence 102 in a defined subset of pilot sequences 102 K It is obtained by summing the corresponding samples in a sample.

[0119] It is possible that the core network equipment 200 could be Figure 1 , Figure 4 or Figure 9 The core network device 200 is shown.

[0120] Optionally, for each pilot sequenceK Before the step of summing corresponding samples in each sample, method 1100 further includes: for each pilot sequence 102, for K Weights are applied to each sample in each pilot chirped carrier sample to produce K A weighted pilot chirped carrier sample. Thus, the pilot signal 103... K Each of the samples is obtained through... N Each pilot sequence 102 in a defined subset of pilot sequences 102 K It is formed by summing the corresponding weighted pilot chirped carrier samples in each sample.

[0121] Optionally, based on the first parameter set 101, obtain N Step 1102 of obtaining the pilot sequence 102 may specifically include: obtaining based on the first parameter set 101 and the second parameter set 104. N A pilot sequence 102, wherein the second parameter set 104 includes the bandwidth of the pilot sequence to be generated and the sampling period for obtaining the pilot chirped carrier sample set for each pilot sequence to be generated. T s).

[0122] Optionally, method 1100 may further include: determining a continuous-time chirped carrier function based on a discrete-time pilot chirped carrier, wherein the discrete-time pilot chirped carrier is parameterized using a first parameter set 101; and by using a sampling rate of 1 / T The pilot chirped carrier sample set is obtained by sampling the continuous-time chirped carrier function.

[0123] Figure 12 A method 1200 provided by an embodiment of this disclosure is illustrated. In a particular embodiment, method 1200 is performed by... Figure 1 , Figure 4 or Figure 9 The core network device 200 shown is executed.

[0124] Method 1200 includes step 1201: providing a first parameter set 101 to one or more network entities 100 for chirp-based pilot sequence generation, wherein the first parameter set 101 includes: the number of pilot sequences to be generated ( N ), the time-domain chirp rate of the pilot sequence to be generated ( ) and the frequency domain chirp rate of the pilot sequence to be generated ( ),in, N It is a positive integer. Possibly, network entity 100 could be... Figure 1 , Figure 4 , Figure 5 , Figure 9 or Figure 10Network entity 100 is shown.

[0125] Figure 13 A method 1300 provided by an embodiment of this disclosure is illustrated. In a particular embodiment, method 1300 is performed by... Figure 4 or Figure 10 The RAN device 300 shown is executed.

[0126] Method 1300 includes step 1301: forwarding a first parameter set 101 received from core network device 200 to one or more network entities 100 for use in chirp-based pilot sequence generation, wherein the first parameter set 101 includes: the number of pilot sequences to be generated ( N ), the time-domain chirp rate of the pilot sequence to be generated ( ) and the frequency domain chirp rate of the pilot sequence to be generated ( ),in, N The value is a positive integer. Method 1300 further includes step 1302: providing a second parameter set 104 to one or more network entities, wherein the second parameter set 104 includes the bandwidth of the pilot sequence to be generated ( ), used to obtain each pilot sequence to be generated K The sampling period of a set of pilot chirped carrier samples ( ), and continuous-time chirped carrier function type.

[0127] It is possible that network entity 100 could be Figure 1 , Figure 4 , Figure 5 , Figure 9 or Figure 10 The network entity 100 shown. The core network device 200 can be... Figure 1 , Figure 4 or Figure 9 The core network device 200 is shown.

[0128] In summary, the embodiments of this application propose: A network entity (which may be a network device or a terminal device) and a corresponding method are used to generate a data structure containing certain parameters (e.g., bandwidth) in the following manner. Center digital frequency AFDM chirp rate AFDM parameters AFDM size A maximum of two window types and and at most two window parameter tuples and (arbitrary length) K ≥ N The mostN A pilot sequence based on AFDM: (Sampling factors above) Most indivual point -AFDM discrete-time chirped carrier sampling is performed using a method greater than the bandwidth. arbitrary speed The formulas for the continuous-time versions of these discrete-time AFDM chirped carriers are sampled.

[0129] One possible continuous-time chirp formula for generating upsampled discrete-time chirped pilots is an exact analog chirped version of the formula for discrete-time AFDM chirped carriers.

[0130] Another possible version of the continuous-time formula is discrete-time. Samples of point AFDM chirped carriers use their Interpolation formula for point DFT coefficients.

[0131] The resulting AFDM-based pilot signal can be added with... The prefix of each sample, which is obtained by finding the interval Internal speed It was obtained by sampling the continuous-time formula.

[0132] The resulting AFDM-based pilot signal can be added with... The suffix of each sample, these samples are obtained by selecting from the interval Internal speed It was obtained by sampling the continuous-time formula.

[0133] One possible way to sample the formula is to calculate the above "online" based on the formula. One sample.

[0134] Another way to sample the formula is to retrieve the required parameters from a lookup table calculated "offline" using different combinations of pilot parameters. One sample.

[0135] The generated length is The pilot sequence can be ordered by frequency. Frequency shifting can be performed, for example, for frequency domain multiplexing of AFDM pilot signals and OFDM.

[0136] The generated length is The pilot sequence and the first A chirped AFDM carrier is associated, which is applied in a segmented window sequence. Pulse shaping is performed, where a chirped segment is defined as the interval between two subsequent discontinuities, and the carrier is shaped using a global window sequence applied per symbol. Perform pulse shaping to provide the first Each chirped carrier generates an effective overall window sequence. .

[0137] Core network nodes: Assign different chirp rate parameters to different network entities. And other cell-specific parameters, such as and This is to signal these parameters to the corresponding terminal devices of these network entities within the corresponding cell areas deployed in these network entities.

[0138] RAN equipment sends signals to the terminal equipment (i.e., network entities) connected to it to notify them of the pilot codebook parameters.

[0139] This disclosure has been described in conjunction with various embodiments as examples and implementations. However, based on a study of the drawings, this disclosure, and the independent claims, those skilled in the art will be able to understand and implement other variations when practicing the claimed embodiments. In the claims and the description, the word "comprising" does not exclude other elements or steps, and "a" or "an" does not exclude a plurality. A single element or other unit may fulfill the function of several entities or items described in the claims. Listing certain measures in dissimilar dependent claims does not indicate that a combination of these measures cannot be used in advantageous implementations.

[0140] Furthermore, any method according to embodiments of this disclosure can be implemented in a computer program having code modules, which, when run by a processing module, causes the processing module to perform the method steps. The computer program is included in a computer-readable medium of the computer program product. The computer-readable medium can substantially include any memory, such as read-only memory (ROM), programmable read-only memory (PROM), erasable PROM (EPROM), flash memory, electrically erasable PROM (EEPROM), or hard disk drive.

[0141] Furthermore, those skilled in the art will recognize that embodiments of network entity 100, core network equipment 200, or RAN equipment 300 include the necessary communication capabilities, in the form of functions, modules, units, elements, etc., for executing the scheme. Other examples of such modules, units, elements, and functions include: processors, memories, buffers, control logic, encoders, decoders, rate matchers, rate-reducing matchers, mapping units, multipliers, decision units, selection units, switches, interleavers, deinterleavers, modulators, demodulators, inputs, outputs, antennas, amplifiers, receiving units, transmitting units, DSPs, trellis-coded modulation (TCM) encoders, TCM decoders, power supply units, power feeders, communication interfaces, communication protocols, etc., which are appropriately arranged together to execute the scheme.

[0142] In particular, for example, one or more processors of network entity 100, core network device 200, or RAN device 300 may include a central processing unit (CPU), processing unit, processing circuitry, processor, application-specific integrated circuit (ASIC), microprocessor, or one or more instances of other processing logic capable of interpreting and executing instructions. The term "processor" can therefore refer to a processing circuitry that includes multiple processing circuits, such as any, some, or all of the items listed above. The processing circuitry may also perform data processing functions for inputting, outputting, and processing data, including data buffering and device control functions such as call processing control, user interface control, etc.

Claims

1. A network entity (100) for generating chirped pilot signals, characterized in that, Used for: Obtain a first parameter set (101) from the core network device (200), wherein the first parameter set (101) includes: the number of pilot sequences to be generated (N), the time-domain chirp rate (c1) of the pilot sequences to be generated, and the frequency-domain chirp rate (c2) of the pilot sequences to be generated, wherein N is a positive integer; Based on the first parameter set (101), N pilot sequences (102) are obtained, wherein each pilot sequence (102) includes a set of K pilot chirped carrier samples, where K is an integer not less than N; For each antenna port of the network entity (100), a subset of the N pilot sequences (102) is determined, and a pilot signal (103) to be transmitted from the antenna port is synthesized based on the newly formed set of K samples, each of the K samples being obtained by summing the corresponding samples of the K samples of each pilot sequence in the determined subset of the N pilot sequences (102).

2. The network entity (100) according to claim 1, characterized in that, The formation of the new set of K samples, each of the K samples being obtained by summing the corresponding samples of the K samples of each pilot sequence in the determined subset of the N pilot sequences (102), includes: For each pilot sequence (102), weights are applied to each of the K pilot chirped carrier samples to generate K weighted pilot chirped carrier samples. Each sample in the new set of K samples of the pilot signal (103) is formed by summing the corresponding weighted pilot chirped carrier samples in the K samples of each pilot sequence (102) in the determined subset of the N pilot sequences (102).

3. The network entity (100) according to claim 1 or 2, characterized in that, Used for: N pilot sequences (102) are obtained based on the first parameter set (101) and the second parameter set (104), wherein the second parameter set (104) includes the bandwidth of the pilot sequence to be generated and the sampling period (Ts) for obtaining the set of K pilot chirped carrier samples for each pilot sequence to be generated.

4. The network entity (100) according to claim 3, characterized in that, Used for: The continuous-time chirped carrier function is determined based on the discrete-time pilot chirped carrier, wherein the discrete-time pilot chirped carrier is parameterized using the first parameter set (101); The pilot chirped carrier sample set is obtained by sampling the continuous-time chirped carrier function at a sampling rate of 1 / Ts.

5. The network entity (100) according to claim 4, characterized in that, The second parameter set (104) also includes a continuous-time chirped carrier function type, wherein, When the continuous-time chirped carrier function type is the first type, the network entity (100) is used to determine the continuous-time chirped carrier function based on the discrete-time pilot chirped carrier using a complex exponential function, wherein the instantaneous frequency of the complex exponential function is a specific step function of the chirped carrier. When the continuous-time chirped carrier function type is the second type, the network entity (100) is used to determine the continuous-time chirped carrier function by applying an interpolation formula to the samples of the discrete-time pilot chirped carrier.

6. The network entity (100) according to claim 3, characterized in that, Used for: Based on the lookup table, the set of the K pilot chirped carrier samples is obtained using the first parameter set (101) and the second parameter set (104).

7. The network entity (100) according to claim 6, characterized in that, Used for: Using the first parameter set (101) and the second parameter set (104), a reference pilot chirped carrier is obtained from the lookup table, wherein the lookup table is a reduced-size lookup table; A sequence of pilot chirped carrier samples is generated by cyclically shifting the reference pilot chirped carrier. Obtain the set of the K pilot chirped carrier samples from the sequence of the K pilot chirped carrier samples.

8. The network entity (100) according to any one of claims 1 to 7, characterized in that, Used for: The synthesized pilot signal (103) is shifted to a predefined frequency by applying a linear phase shift to the N pilot sequences (102) obtained therefrom.

9. The network entity (100) according to any one of claims 3 to 8, characterized in that, The second parameter set (104) also includes a window function type and one or more window parameters corresponding to the window function type.

10. The network entity (100) according to claim 9, characterized in that, Used for: Pulse shaping is performed on the m-th pilot sequence (102) by applying a window function to the K pilot chirped carrier samples of the m-th pilot sequence (102) among the N pilot sequences (102) based on the first parameter set (101), the second parameter set (104) and the value of m, where m is the index of the pilot sequence (102) among the N pilot sequences (102).

11. The network entity (100) according to claim 10, characterized in that, The window function types include global window function types and / or segmented window function types, wherein the network entity (100) is further used for: When the window function type is the global window function type, the global window function is applied to each of the K pilot chirped carrier samples, and / or When the window function type is the segmented window function type, the segmented window function is applied to each pilot chirped carrier sample within the chirped segment of the K pilot chirped carrier samples.

12. The network entity (100) according to any one of claims 1 to 11, characterized in that, Used for: Add sample prefixes and / or sample suffixes to the K pilot chirped carrier samples of the pilot signal (103), wherein the sample prefix includes one of the following: a chirped periodic prefix, a periodic prefix, or a zero-value prefix, and / or the sample suffix includes one of the following: a chirped periodic suffix, a periodic suffix, or a zero-value suffix.

13. The network entity (100) according to any one of claims 1 to 12, characterized in that, The network entity (100) is implemented in the terminal device (400), wherein the network entity (100) is further used for: Obtain the second parameter set (104) from the wireless access network device (300). The first parameter set (101) is received from the core network device (200) via the wireless access network device (300).

14. The network entity (100) according to any one of claims 1 to 12, characterized in that, The network entity (100) is implemented in the wireless access network device (300), wherein the network entity (100) is further used for: Determine the second parameter set (104).

15. A core network device (200), characterized in that, Used for: A first set of parameters (101) is provided to one or more network entities (100) for chirp-based pilot sequence generation, wherein the first set of parameters (101) includes: the number of pilot sequences to be generated (N), the time-domain chirp rate (c1) of the pilot sequences to be generated, and the frequency-domain chirp rate (c2) of the pilot sequences to be generated, wherein N is a positive integer.

16. The core network device (200) according to claim 15, characterized in that, The time-domain chirp rate (c1) assigned to different network entities (100) is selected to have different values.

17. A wireless access network device (300), characterized in that, Used for: A first set of parameters (101) received from a core network device (200) is forwarded to one or more network entities (100) for use in generating chirp-based pilot sequences, wherein the first set of parameters (101) includes: the number of pilot sequences to be generated (N), the time-domain chirp rate (c1) of the pilot sequences to be generated, and the frequency-domain chirp rate (c2) of the pilot sequences to be generated, wherein N is a positive integer; A second set of parameters (104) is provided to the one or more network entities (100), wherein the second set of parameters (104) includes the bandwidth of the pilot sequence to be generated, the sampling period (Ts) for obtaining the pilot chirped carrier sample set for each pilot sequence to be generated, and the continuous time chirped carrier function type.

18. The wireless access network device (300) according to claim 17, characterized in that, The second parameter set (104) also includes a window function type and one or more window parameters corresponding to the window function type, wherein the window function type includes a global window function type and / or a segmented window function type.

19. A method (1100) for generating chirped pilot sequences performed by a network entity (100), characterized in that, include: Obtain (1101) a first parameter set (101) from the core network device (200), wherein the first parameter set (101) includes: the number of pilot sequences to be generated (N), the time-domain chirp rate (c1) of the pilot sequences to be generated and the frequency-domain chirp rate (c2) of the pilot sequences to be generated, wherein N is a positive integer; Based on the first parameter set (101), N pilot sequences (102) are obtained (1102), wherein each pilot sequence (102) includes a set of K pilot chirped carrier samples, where K is an integer not less than N; For each antenna port of the network entity (100), determine (1103) a subset of the N pilot sequences (102); Based on the newly formed set of K samples, a pilot signal (103) to be transmitted from the antenna port is synthesized (1104), each of the K samples being obtained by summing the corresponding samples of the K samples of each pilot sequence (102) in the determined subset of the N pilot sequences (102).

20. The method (1100) according to claim 19, characterized in that, include: For each pilot sequence (102), weights are applied to each of the K pilot chirped carrier samples to generate K weighted pilot chirped carrier samples. Each of the K samples of the pilot signal (103) is formed by summing the corresponding weighted pilot chirped carrier samples in the K samples of each pilot sequence (102) in the determined subset of the N pilot sequences (102).

21. The method (1100) according to claim 19 or 20, characterized in that, include: N pilot sequences (102) are obtained based on the first parameter set (101) and the second parameter set (104), wherein the second parameter set (104) includes the bandwidth of the pilot sequence to be generated and the sampling period (Ts) for obtaining the pilot chirped carrier sample set of each pilot sequence to be generated.

22. The method (1100) according to claim 21, characterized in that, include: The continuous-time chirped carrier function is determined based on the discrete-time pilot chirped carrier, wherein the discrete-time pilot chirped carrier is parameterized using the first parameter set (101); The pilot chirped carrier sample set is obtained by sampling the continuous-time chirped carrier function at a sampling rate of 1 / Ts.

23. A method (1200) performed by a core network device (200), characterized in that, include: A first parameter set (101) is provided (1201) to one or more network entities (100) for chirp-based pilot sequence generation, wherein the first parameter set (101) includes: the number (N) of pilot sequences to be generated, the time-domain chirp rate (c1) of the pilot sequences to be generated, and the frequency-domain chirp rate (c2) of the pilot sequences to be generated, wherein N is a positive integer.

24. A method (1300) performed by a wireless access network device (300), characterized in that, include: Forward (1301) a first set of parameters (101) received from the core network device (200) to one or more network entities (100) for chirp-based pilot sequence generation, wherein the first set of parameters (101) includes: the number of pilot sequences to be generated (N), the time-domain chirp rate (c1) of the pilot sequences to be generated, and the frequency-domain chirp rate (c2) of the pilot sequences to be generated, wherein N is a positive integer; Provide (1302) a second parameter set (104) to the one or more network entities, wherein the second parameter set (104) includes the bandwidth of the pilot sequence to be generated, the sampling period (Ts) for obtaining the pilot carrier sample set of each pilot sequence to be generated, and the continuous time chirped carrier function type.

25. A computer program product including program code, characterized in that, When executed by a processor, the program code causes the processor to perform the method according to claim 22, 23 or 24.

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