Pilot pattern generation method, apparatus, electronic device and storage medium

Abstract

This application discloses a pilot pattern generation method, apparatus, electronic device, and storage medium, relating to the field of communications. The pilot pattern generation method includes: obtaining the position of each pilot in a first time slot based on a pre-acquired pilot interval and a preset position of the deepest fading subcarrier; obtaining the step frequency of each pilot in each time slot based on a preset pilot cycle period, time slot size, total number of subcarriers, total number of pilots in each time slot, OFDM symbol period, and pre-acquired negotiation parameters for controlling the step amplitude of each pilot; obtaining the position change of each pilot in each time slot based on the pilot cycle period, time slot size, and the step frequency of each pilot in each time slot; obtaining the position of each pilot in each time slot based on the position of each pilot in the first time slot and the position change of each pilot in each time slot; and generating a pilot pattern at any time based on the position of each pilot in each time slot.

Description

Technical Field

[0001] This application relates to the field of communications, and in particular to a pilot pattern generation method, apparatus, electronic device, and storage medium. Background Technology

[0002] Pilot patterns are a technique used for channel estimation. During the estimation process, the two communicating parties agree to send signals known to both parties at fixed locations to measure the unknown channel. The specific location of the signals in the time and frequency domain is called the pilot pattern.

[0003] Currently, pilot pattern design simply involves inserting pilots at fixed frequency points. However, various communication technologies are increasingly inclined to use higher transmission rates and higher bandwidths. This leads to communication parties facing channels with more severe frequency-selective fading. If the fading frequency of the channel where the communication equipment is located changes at a certain moment, and if the pilot position inserted at the fixed frequency point is far from the fading point and the fading is deep, the fading point is difficult to estimate and will cause a large channel estimation error. Summary of the Invention

[0004] The main objective of this application is to provide a pilot pattern generation method, apparatus, electronic device, and storage medium, which aims to generate a pilot pattern in which the pilot position changes over time. Channel estimation using this pilot pattern can effectively solve the problem of difficulty in estimating fading points.

[0005] To achieve the above objectives, embodiments of this application provide a pilot pattern generation method, comprising: obtaining the position of each pilot in a first time slot based on a pre-acquired pilot interval and a preset position of the deepest fading subcarrier; obtaining the step frequency of each pilot in each time slot based on a preset pilot cycle period, time slot size, total number of subcarriers, total number of pilots in each time slot, Orthogonal Frequency Division Multiplexing (OFDM) symbol period, and pre-acquired negotiation parameters for controlling the step amplitude of each pilot; obtaining the position change of each pilot in each time slot based on the pilot cycle period, the time slot size, and the step frequency of each pilot in each time slot; obtaining the position of each pilot in each time slot based on the position of each pilot in the first time slot and the position change of each pilot in each time slot, and generating a pilot pattern based on the position of each pilot in each time slot.

[0006] To achieve the above objectives, embodiments of this application also propose a pilot pattern generation apparatus, comprising:

[0007] The pilot parameter calculation module is used to: obtain the position of each pilot in the first time slot based on the pre-acquired pilot interval and the preset deepest fading subcarrier position; obtain the step frequency of each pilot in each time slot based on the preset pilot cycle period, time slot size, total number of subcarriers, total number of pilots in each time slot, OFDM symbol period, and pre-acquired negotiation parameters for controlling the step amplitude of each pilot; obtain the position change of each pilot in each time slot based on the pilot cycle period, the time slot size, and the step frequency of each pilot in each time slot; and obtain the position of each pilot in each time slot based on the position of each pilot in the first time slot and the position change of each pilot in each time slot.

[0008] The pilot pattern generation module is used to generate a pilot pattern based on the position of each pilot in each time slot.

[0009] To achieve the above objectives, embodiments of this application also propose an electronic device, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the pilot pattern generation method described in the above embodiments.

[0010] To achieve the above objectives, embodiments of this application also propose a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the pilot pattern generation method described in the above embodiments.

[0011] This application proposes a pilot pattern generation method, apparatus, electronic device, and storage medium. The method obtains the position of each pilot in each time slot by calculating the position of each pilot in the first time slot, the step frequency of each pilot in each time slot, and the position change of each pilot in each time slot, and then obtains a complete pilot pattern at any given time. This pilot pattern, where the pilot position changes over time, effectively solves the problem of difficulty in estimating fading points when severe frequency domain fading occurs during channel estimation, improving channel estimation accuracy without adding any spectral overhead. It also helps the receiver obtain richer frequency domain estimates, allowing for more flexible selection of channel estimation algorithms. Attached Figure Description

[0012] One or more embodiments are illustrated by way of example with reference to the accompanying drawings, and these illustrative descriptions do not constitute a limitation on the embodiments.

[0013] Figure 1 This is a flowchart of a pilot pattern generation method provided in an embodiment of this application;

[0014] Figure 2This is a schematic diagram of the pilot pattern generation device provided in an embodiment of this application;

[0015] Figure 3 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the various embodiments of this application will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the various embodiments of this application to help readers better understand this application. However, the technical solutions claimed in this application can be implemented even without these technical details and various changes and modifications based on the following embodiments. The division of the various embodiments below is for the convenience of description and should not constitute any limitation on the specific implementation of this application. The various embodiments can be combined with and referenced by each other without contradiction.

[0017] The pilot pattern generation method in this application is mainly aimed at Carrier Sense Multiple Access (CSMA) communication systems, especially in the WIFI scenario. CSMA technology refers to a communication device acquiring a connection and link with an access device through contention. After acquiring the link, the communication device exclusively uses all frequency band resources (all subcarriers) of the entire link. The 802.11 protocol provides a complete and general scheme for channel estimation using pilots in CSMA access scenarios. This scheme mainly consists of three parts: a long training field (LTF) phase, a short training field (STF) phase, and a tracking phase. The LTF is used for detailed pilot estimation, filling the entire frequency band with pilots. The STF is used for synchronization and coarse pilot estimation, with sparse co-frequency patterns. These two pilots are used for preliminary channel estimation. The tracking phase uses pilots distributed across four carriers for tracking, and performs real-time corrections to the preliminary estimate. The protocol stipulates that there are four pilot signals in this phase, located on subcarriers -21, -4, 4, and 21, and transmitted at equal time intervals.

[0018] Currently, pilot pattern design simply involves inserting pilots at fixed frequency points and obtaining channel parameters at different times by repeatedly measuring the pilots at these fixed frequency points.

[0019] However, in Wi-Fi scenarios, the channel state is quasi-static rather than completely static. Quasi-static means that the channel state changes slowly over time. On the one hand, because the channel state is quasi-static in Wi-Fi scenarios, terminal devices often do not move rapidly or continuously. Therefore, repeatedly measuring a single frequency point is a significant waste of spectrum resources, and measuring only one frequency point is not conducive to deploying a better-performing channel estimation algorithm at the receiver. On the other hand, with the development of Wi-Fi technology and the evolution of the 802.11 standard, the Wi-Fi physical layer increasingly tends to use high-frequency, high-bandwidth modulation methods to meet users' growing data rate demands. Higher transmission frequencies and larger transmission bandwidths will lead to wireless channels with more severe frequency-selective fading for both communicating parties. In this case, if the fading frequency of the channel where the communicating device is located changes at a certain moment, and if the pilot position inserted at a fixed frequency point is far from the fading point and the fading is deep, the fading point is difficult to estimate and will cause a large channel estimation error.

[0020] This application improves the accuracy of channel estimation by generating a pilot pattern in which the pilot position changes over time, especially in fading channels, where it can effectively track and locate the position of the fading point.

[0021] Embodiments of this application relate to a pilot pattern generation method, such as... Figure 1 As shown, it includes:

[0022] Step 101: Based on the pre-acquired pilot interval and the preset deepest fading subcarrier position, obtain the position of each pilot in the first time slot.

[0023] It should be noted that the pilot pattern generation method of this application is applied to a Carrier Sense Multiple Access (CSMA) communication system, and the pilot pattern is used for the short training phase (STF) of channel estimation. Specifically, the position of each pilot in the first time slot is calculated using the following formula:

[0024]

[0025] in, This indicates the insertion position of the i-th pilot in the k-th time slot. f represents the insertion position of the i-th pilot in the first time slot. p This represents the pilot spacing. It's worth noting that, in order to effectively track the location of fading points, the position of the first pilot in the first time slot is defined as the position f of the deepest fading subcarrier obtained during the long training phase. deep ,Right now In this way, after the fading point is determined during the long training process, the position of the fading point can be used as the starting point for the short training process, and the subsequent movement position of the fading point can be tracked quickly and effectively.

[0026] Additionally, the preset deepest fading subcarrier position f deep This is obtained from the long training phase of channel estimation. Specifically, it is determined based on the absolute value of the channel tap coefficients at each frequency point output from the long training phase. When the absolute value of the channel tap coefficient is less than a preset threshold, the frequency point corresponding to that channel tap coefficient is the location of the deepest fading subcarrier.

[0027] In one embodiment, prior to step 101, the method further includes: determining the pilot spacing based on the total number of pilots in each time slot, the total number of subcarriers, and the OFDM symbol period. Specifically, the pilot spacing is calculated using the following formula:

[0028]

[0029] Among them, f p N represents the pilot spacing. sub N represents the total number of subcarriers. pilot T represents the total number of pilots in each time slot. symbol Indicates the OFDM symbol period. This indicates rounding down to the nearest integer.

[0030] In this embodiment, the parameters such as the total number of pilots, the total number of subcarriers, and the OFDM symbol period for each time slot are set according to the 802.11 protocol or its evolution protocol. Based on this, in one embodiment, the total number of pilots in each time slot is negatively correlated with a first parameter, which indicates the channel quality. Specifically, when the channel quality is good, the number of pilots in each time slot can be reduced to improve the data transmission rate. Those skilled in the art will understand that the total number of subcarriers in a time slot is fixed; some subcarriers carry pilots, and others carry service data. Therefore, when too many subcarriers carry pilots, the transmission rate of service data will be significantly reduced.

[0031] In other words, the total number of pilot signals can be set to a fixed value or a non-fixed value. When it is a non-fixed value, it is adjusted according to the channel quality.

[0032] Step 102: Based on the preset pilot cycle period, time slot size, total number of subcarriers, total number of pilots in each time slot, OFDM symbol period, and the pre-acquired negotiation parameters for controlling the step amplitude of each pilot, obtain the step frequency of each pilot in each time slot.

[0033] In this embodiment, parameters such as time slot size, total number of pilots per time slot, total number of subcarriers, and OFDM symbol period are set according to the 802.11 protocol or its evolution protocols. It should be noted that the pilot cycle period is less than the channel coherence time. Channel coherence time refers to the time during which the channel state remains unchanged. When the pilot cycle period is less than the coherence time, the estimates of all frequency points obtained within one period can be combined and used as a single estimate, or they can be used separately for channel estimation or flexibly combined, providing a more flexible channel estimation algorithm. Furthermore, preferably, the pilot cycle period can be set to an integer multiple of the OFDM symbol period to improve the calculation speed and accuracy.

[0034] In one embodiment, prior to step 102, the method further includes: acquiring a first parameter for indicating channel quality; determining the negotiation parameter based on the first parameter; wherein the first parameter includes one or any combination of the following: Channel Quality Indicator (CQI), Signal-to-Noise Ratio (SNR), and Symbol Error Rate (SER), and the first parameter is negatively correlated with the negotiation parameter.

[0035] Specifically, the step frequency for each pilot in each time slot is calculated using the following formula:

[0036]

[0037] Where, Δf i T represents the step frequency of each pilot in each time slot. pilot The pilot cycle period is represented by Δt, where Δt represents the time slot size, and n is the number of pilot cycles. i n represents the negotiation parameter. i The range of values ​​satisfies And n i It is an integer.

[0038] In this embodiment, the calculation method of the step frequency allows for uniform scanning of frequencies within the pilot coverage area within a pre-set pilot cycle period. For example, with 1024 subcarriers, 4 pilots, and a pilot cycle period of 4, when the negotiation parameter is set to 1, the step frequency will reach 64, resulting in very low scanning resolution. When the negotiation parameter is set to ni = 2, the step frequency will reach 32, improving the resolution. The scanning range is reduced from 256 subcarriers to 128 of them. Combined with the initial position of deep fading obtained during long training, this allows for better tracking of channel fading. In other words, when the channel quality is good, the scanning resolution can be reduced; when the channel quality is poor, the scanning resolution can be increased. The process of pilot position changing over time is called frequency scanning.

[0039] Step 103: Based on the pilot cycle period, time slot size, and step frequency of each pilot in each time slot, obtain the position change of each pilot in each time slot.

[0040] Step 104: Based on the position of each pilot in the first time slot and the position change of each pilot in each time slot, obtain the position of each pilot in each time slot, and generate a pilot pattern based on the position of each pilot in each time slot.

[0041] In this embodiment, the following formula is specifically used to calculate the position change of each pilot in each time slot and the position of each pilot in each time slot:

[0042]

[0043]

[0044] in, This represents the change in position of the i-th pilot in the k-th time slot. This indicates the position of the i-th pilot in the k-th time slot.

[0045] This application proposes a pilot pattern generation method. The method calculates the position of each pilot in each time slot, the step frequency of each pilot in each time slot, and the position change of each pilot in each time slot to obtain the position of each pilot in each time slot. Based on this, a complete pilot pattern at any given time is obtained. This pilot pattern, where the pilot position changes over time, effectively solves the problem of difficulty in estimating fading points when severe frequency domain fading occurs during channel estimation, improving channel estimation accuracy without adding any spectral overhead. It helps the receiver obtain richer frequency domain estimates, thus allowing for more flexible selection of channel estimation algorithms.

[0046] Furthermore, it should be understood that the step divisions of the various methods described above are only for clarity. In practice, they can be combined into one step or some steps can be split into multiple steps. As long as they include the same logical relationship, they are all within the scope of protection of this patent. Adding insignificant modifications or introducing insignificant designs to the process, but without changing the core design of the process, are also within the scope of protection of this patent.

[0047] Embodiments of this application relate to a pilot pattern generation apparatus, such as... Figure 2 As shown, it includes:

[0048] The pilot parameter calculation module 201 is used to: obtain the position of each pilot in the first time slot based on the pre-acquired pilot interval and the preset deepest fading subcarrier position; obtain the step frequency of each pilot in each time slot based on the preset pilot cycle period, time slot size, total number of subcarriers, total number of pilots in each time slot, OFDM symbol period, and pre-acquired negotiation parameters for controlling the step amplitude of each pilot; obtain the position change of each pilot in each time slot based on the pilot cycle period, the time slot size, and the step frequency of each pilot in each time slot; and obtain the position of each pilot in each time slot based on the position of each pilot in the first time slot and the position change of each pilot in each time slot.

[0049] Pilot pattern generation module 202 is used to generate pilot patterns based on the position of each pilot in each time slot.

[0050] It should be noted that the entire pilot pattern generation device can be deployed in any device in a Carrier Sense Multiple Access (CSMA) communication system, such as user equipment or Wi-Fi devices.

[0051] It is worth mentioning that all modules involved in this embodiment are logical modules. A logical unit can be a physical unit, a part of a physical unit, or a combination of multiple physical units. Furthermore, to highlight the innovative aspects of this invention, this embodiment does not introduce units that are not closely related to solving the technical problem proposed by this invention; however, this does not mean that other units are absent from this embodiment.

[0052] It is not difficult to see that this embodiment is a device embodiment corresponding to the pilot pattern generation method embodiment, and this embodiment can be implemented in conjunction with the above embodiments. The relevant technical details mentioned in the above embodiments are still valid in this embodiment, and will not be repeated here to reduce repetition. Accordingly, the relevant technical details mentioned in this embodiment can also be applied to the above method embodiments.

[0053] Embodiments of the present invention relate to an electronic device, such as... Figure 3As shown, it includes: at least one processor 301; and a memory 302 communicatively connected to the at least one processor 301; wherein the memory 302 stores instructions executable by the at least one processor 301, the instructions being executed by the at least one processor 301 to enable the at least one processor 301 to execute the pilot pattern generation method of the above embodiment.

[0054] The memory and processor are connected via a bus, which can include any number of interconnecting buses and bridges, connecting various circuits of one or more processors and memories. The bus can also connect various other circuits, such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and will not be described further herein. The bus interface provides an interface between the bus and the transceiver. The transceiver can be a single element or multiple elements, such as multiple receivers and transmitters, providing a unit for communicating with various other devices over a transmission medium. Data processed by the processor is transmitted over the wireless medium via an antenna, which further receives data and transmits it to the processor.

[0055] The processor manages the bus and general processing, and also provides various functions, including timing, peripheral interfaces, voltage regulation, power management, and other control functions. Memory is used to store data used by the processor during operation.

[0056] Embodiments of the present invention relate to a computer-readable storage medium storing a computer program. When executed by a processor, the computer program implements the above-described pilot pattern generation method.

[0057] That is, those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. This program is stored in a storage medium and includes several instructions to cause a device (which may be a microcontroller, chip, etc.) or processor to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0058] Those skilled in the art will understand that the above embodiments are specific embodiments for implementing this application, and in practical applications, various changes can be made to them in form and detail without departing from the spirit and scope of this application.

Claims

1. A method for generating pilot patterns, characterized in that, include: Based on the pre-acquired pilot interval and the preset deepest fading subcarrier position, obtain the position of each pilot in the first time slot; Based on the preset pilot cycle period, time slot size, total number of subcarriers, total number of pilots in each time slot, OFDM symbol period, and pre-acquired negotiation parameters for controlling the step amplitude of each pilot, the step frequency of each pilot in each time slot is obtained. Based on the pilot cycle period, the time slot size, and the step frequency of each pilot in each time slot, the position change of each pilot in each time slot is obtained; Based on the position of each pilot in the first time slot and the position change of each pilot in each time slot, the position of each pilot in each time slot is obtained, and a pilot pattern is generated based on the position of each pilot in each time slot.

2. The pilot pattern generation method according to claim 1, characterized in that, Before obtaining the position of each pilot in the first time slot based on the pre-acquired pilot spacing and the preset deepest fading subcarrier position, the method further includes: The pilot interval is determined based on the total number of pilots in each time slot, the total number of subcarriers, and the OFDM symbol period.

3. The pilot pattern generation method according to claim 1 or 2, characterized in that, Before obtaining the step frequency of each pilot in each time slot based on the preset pilot cycle period, time slot size, total number of subcarriers, total number of pilots in each time slot, OFDM symbol period, and pre-acquired negotiation parameters for controlling the step amplitude of each pilot, the process further includes: Obtain the first parameter used to indicate channel quality; The negotiation parameters are determined based on the first parameter; The first parameter includes one or any combination of the following: Channel Quality Indicator (CQI), Signal-to-Noise Ratio (SNR), and Bit Error Rate (BER), and the first parameter is negatively correlated with the negotiated parameter.

4. The pilot pattern generation method according to claim 3, characterized in that, The total number of pilots in each time slot is negatively correlated with the first parameter.

5. The pilot pattern generation method according to claim 1, characterized in that, The pilot cycle period is less than the channel coherence time.

6. The pilot pattern generation method according to claim 1, characterized in that, The location of the deepest fading subcarrier is obtained based on the long training phase of channel estimation.

7. The pilot pattern generation method according to any one of claims 1 to 6, characterized in that, The method is applied to a Carrier Sense Multiple Access (CSMA) communication system, and the pilot pattern is used for a short training phase of channel estimation.

8. A pilot pattern generating device, characterized in that, include: The pilot parameter calculation module is used to obtain the position of each pilot in the first time slot based on the pre-acquired pilot interval and the preset position of the deepest fading subcarrier; Based on the preset pilot cycle period, time slot size, total number of subcarriers, total number of pilots in each time slot, OFDM symbol period, and pre-acquired negotiation parameters for controlling the step amplitude of each pilot, the step frequency of each pilot in each time slot is obtained; based on the pilot cycle period, the time slot size, and the step frequency of each pilot in each time slot, the position change of each pilot in each time slot is obtained; based on the position of each pilot in the first time slot and the position change of each pilot in each time slot, the position of each pilot in each time slot is obtained. The pilot pattern generation module is used to generate a pilot pattern at any time based on the position of each pilot in each time slot.

9. An electronic device, characterized in that, include: At least one processor; as well as, A memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform the pilot pattern generation method as described in any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the pilot pattern generation method according to any one of claims 1 to 7.

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