An Integrated Communication and Navigation Signal Transmission Method Based on OCDM

Abstract

This invention provides an integrated communication and navigation signal transmission method based on OCDM, relating to the field of signal transmission. The method includes: acquiring a target transmission symbol sequence carrying navigation and communication data; generating a set of orthogonal linear frequency modulated carrier signals divided into navigation subcarrier blocks and communication subcarrier blocks, wherein the pilot ratio of the navigation subcarrier blocks is greater than that of the communication subcarrier blocks; modulating preset pilot data, navigation data, and communication data onto the subcarrier signals in the corresponding subcarrier blocks; superimposing the modulated subcarrier block signals to obtain a transmission signal, which is then sent to the receiving end. Through this method, integrated transmission of communication and navigation data under a unified signal framework can be achieved, effectively solving the problems of weak coordination and wasted spectrum resources in traditional communication and navigation systems, improving spectrum utilization efficiency, and achieving a dynamic balance between communication efficiency and navigation accuracy, thus enhancing the flexibility and scalability of signal transmission.

Description

Technical Field

[0001] This invention relates to the field of signal transmission, and in particular to an integrated communication and navigation signal transmission method based on OCDM. Background Technology

[0002] With the rapid development of technologies such as mobile communication, navigation and positioning, and artificial intelligence, the demand for the integration of communication and navigation systems is constantly increasing. Traditional communication and navigation systems are typically designed independently, employing different waveforms, modulation methods, and receiver structures. This not only results in hardware redundancy and high system complexity but also makes it difficult to meet the comprehensive performance requirements of modern application scenarios such as high-speed mobility, multi-user access, and precise positioning. In practical applications, communication and navigation have a natural foundation for integration. Navigation systems can provide location information and time references to communication systems, assisting in resource scheduling and location-related services; while communication systems can optimize the reception accuracy of navigation signals and improve overall positioning performance through techniques such as channel estimation. Therefore, integrated design has become an important trend in the development of next-generation information and communication systems.

[0003] However, existing integrated communication and navigation designs still face many challenges, such as poor coordination due to independent signal structures, inability to simultaneously address communication and navigation, and low system robustness and flexibility. Especially in complex environments with significant multipath interference and scarce spectrum resources, traditional communication or navigation signal structures struggle to accommodate dual functions, resulting in low functional integration and low spectrum utilization efficiency. Summary of the Invention

[0004] This invention provides an integrated communication and navigation signal transmission method based on OCDM to solve the problems of weak communication and navigation coordination and wasted spectrum resources caused by the separation of traditional communication and navigation systems. The method includes a transmission part, which includes:

[0005] Step 11, obtain the target transmission symbol sequence; the target transmission symbol sequence includes a navigation data sequence and a communication data sequence;

[0006] Step 12: Generate a set of orthogonal linear frequency modulated carrier signals; wherein the linear frequency modulated carrier signals include multiple subcarrier signals, the subcarrier signals are divided into multiple subcarrier blocks, the subcarrier blocks include navigation subcarrier blocks and communication subcarrier blocks; the pilot ratio of the navigation subcarrier blocks is greater than the pilot ratio of the communication subcarrier blocks;

[0007] Step 13: Modulate the preset first pilot data and the navigation data sequence onto the subcarrier signal in the navigation subcarrier block, modulate the preset second pilot data and the communication data sequence onto the subcarrier signal in the communication subcarrier block, and superimpose the modulated navigation subcarrier block signal and the modulated communication subcarrier block signal to obtain the transmission signal;

[0008] Step 14: Send the transmitted signal to the receiving end.

[0009] Optionally, the transmitted signal includes a modulated navigation subcarrier block signal and a modulated communication subcarrier block signal; the modulated communication subcarrier block signal includes a cyclic prefix portion, a pilot portion, and a communication data payload portion, and the modulated navigation subcarrier block signal includes a cyclic prefix portion, a pilot portion, and a navigation data payload portion.

[0010] Optionally, the pilot ratio of the communication subcarrier block is 5% to 10%, and the pilot ratio of the navigation subcarrier block is 20% to 35%.

[0011] Optionally, step 13 includes:

[0012] Add a function identifier to the subcarrier block; the function identifier is used to distinguish between communication subcarrier blocks and navigation subcarrier blocks.

[0013] Based on the functional identifier, the preset first pilot data and the navigation data sequence are modulated onto the subcarrier signal in the navigation subcarrier block, the preset second pilot data and the communication data sequence are modulated onto the subcarrier signal in the communication subcarrier block, and the modulated navigation subcarrier block signal and the modulated communication subcarrier block signal are superimposed to obtain the transmission signal.

[0014] Optionally, step 11 includes:

[0015] Acquire a bit stream to be transmitted, wherein the bit stream to be transmitted includes communication data and navigation data;

[0016] The navigation data in the bit stream to be transmitted is mapped according to a preset first mapping method, and the communication data in the bit stream to be transmitted is mapped according to a preset second mapping method to obtain a target transmission symbol sequence, wherein the order of the second mapping method is greater than the order of the first mapping method.

[0017] Optionally, the method further includes a receiving portion, the receiving portion comprising:

[0018] Step 21: Receive the transmitted signal from the transmitting end to obtain the received signal; the received signal includes a subcarrier block carrying the transmitted data;

[0019] Step 22: Perform matched filtering on the received signal to restore the target transmission symbol sequence.

[0020] Optionally, the method further includes:

[0021] Step 231: Construct a discrete-time model of signal transmission according to the following formula:

[0022] ,

[0023] in, The impulse response represents the signal transmission; L represents the effective multipath number determined by the receiver. For the first Path complex gain, For the first Road delay, It is a unit impulse function. The sampling time;

[0024] Step 232: Calculate the gain of each subcarrier in the received signal according to the following formula:

[0025] ,

[0026] in, This represents the gain of the k-th subcarrier in the received signal in the frequency domain, where K is the total number of subcarriers in the received signal.

[0027] Optionally, the method further includes:

[0028] Step 241: Calculate the pilot-related navigation error term of the received signal according to the following formula:

[0029] ,

[0030] in, B represents the pilot-related navigation error term of the received signal; B represents the number of subcarrier blocks in the received signal. Used to indicate the type of the b-th subcarrier block, when When the b-th subcarrier block is the navigation subcarrier block, when At that time, the b-th subcarrier block is a communication subcarrier block; The pilot ratio of the b-th subcarrier block is represented by N, and N represents the number of subcarriers in a subcarrier block.

[0031] Step 242: Calculate the navigation data error within each navigation subcarrier block according to the following formula:

[0032] ,

[0033] in, This represents the navigation data error of the b-th subcarrier block in the received signal. When the b-th subcarrier block is a communication subcarrier block, the navigation data error is not calculated. This represents the standard deviation of the power of each subcarrier in the b-th subcarrier block of the received signal. This indicates the phase jitter level of the b-th subcarrier block; This indicates the order of the mapping method used for the transmitted data carried by the b-th subcarrier block in the received signal. express The minimum constellation spacing corresponding to the mapping method of order; and These are empirical weighting coefficients;

[0034] Step 243: Calculate the average navigation data error in the received signal based on the navigation data error within each subcarrier block;

[0035] Step 244: Based on the pilot-related navigation error term and the average navigation data error, calculate the navigation data transmission accuracy of the received signal according to a preset weighting factor.

[0036] Optionally, the method further includes:

[0037] Step 25: Calculate the overall communication rate based on the received signal using the following formula:

[0038] ,

[0039] in, B represents the overall communication rate; B represents the number of subcarrier blocks in the received signal, and N represents the number of subcarriers in a subcarrier block. This represents the pilot ratio of the b-th subcarrier block in the received signal. This indicates the number of subcarriers used for data transmission in a subcarrier block; This indicates the order of the mapping method used for the transmitted data carried by the b-th subcarrier block in the received signal.

[0040] Optionally, the method further includes:

[0041] Step 261: Calculate the bit error rate of each subcarrier according to the following formula:

[0042] ,

[0043] in, This represents the bit error rate of the k-th subcarrier in the b-th subcarrier block of the received signal; This indicates the order of the mapping method used for the transmitted data carried by the b-th subcarrier block in the received signal; This represents the channel gain in the frequency domain of the k-th subcarrier within the b-th subcarrier block of the received signal. This represents the transmit power corresponding to the k-th subcarrier in the b-th subcarrier block of the received signal. The channel noise power spectral density; It is a Gaussian Q-function;

[0044] Step 262: Calculate the average bit error rate based on the bit error rate of each subcarrier to obtain the overall bit error rate of transmitting the received signal.

[0045] The embodiments described in this invention have the following advantages:

[0046] This invention provides an integrated communication and navigation signal transmission method based on OCDM. The method involves acquiring a target transmission symbol sequence carrying navigation and communication data, generating a set of orthogonal linear frequency modulated (LFM) carrier signals, wherein these LFM carrier signals are divided into navigation subcarrier blocks and communication subcarrier blocks, with the pilot ratio of the navigation subcarrier blocks being greater than that of the communication subcarrier blocks; modulating a preset first pilot data and the navigation data sequence onto the subcarrier signals in the navigation subcarrier blocks, and modulating a preset second pilot data and the communication data sequence onto the subcarrier signals in the communication subcarrier blocks; then superimposing the modulated navigation subcarrier block signals and the modulated communication subcarrier block signals to obtain a transmission signal; and finally transmitting the transmission signal to a receiving end.

[0047] In the above approach, a set of orthogonal linear frequency modulated carrier signals is divided into communication subcarrier blocks and navigation subcarrier blocks. This enables the integrated transmission of communication and navigation data within a unified signal framework, effectively solving the problems of resource separation, weak coordination, and wasted spectrum resources in traditional communication and navigation systems, and improving spectrum utilization efficiency. At the same time, by using differentiated pilot resource allocation methods, a higher proportion of pilot resources are configured in the navigation subcarrier blocks to improve time and frequency synchronization and positioning accuracy, while data throughput is prioritized in the communication subcarrier blocks. This achieves a dynamic balance between communication efficiency and navigation accuracy, thereby improving the flexibility and scalability of signal transmission. Attached Figure Description

[0048] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0049] Figure 1 A flowchart illustrating the steps of an embodiment of the communication and navigation integrated signal transmission method based on OCDM provided by the present invention;

[0050] Figure 2This is a structural diagram of a signal transmission method provided in an embodiment of the present invention. Detailed Implementation

[0051] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0052] Reference Figure 1 The present invention provides a flowchart of an embodiment of an integrated communication and navigation signal transmission method based on OCDM, wherein the method includes a transmitting part, the transmitting part comprising:

[0053] Step 11, obtain the target transmission symbol sequence; the target transmission symbol sequence includes a navigation data sequence and a communication data sequence.

[0054] The target transmission symbol sequence refers to the constellation point symbol sequence obtained by mapping the data bit stream using a preset constellation diagram, carrying the transmission data. The transmission data includes navigation data and communication data, i.e., navigation data sequence and communication data sequence. The mapping methods include, but are not limited to, binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), and quadrature amplitude modulation (QAM).

[0055] Step 12: Generate a set of orthogonal linear frequency modulated carrier signals; wherein the linear frequency modulated carrier signals include multiple subcarrier signals, the subcarrier signals are divided into multiple subcarrier blocks, the subcarrier blocks include navigation subcarrier blocks and communication subcarrier blocks; the pilot ratio of the navigation subcarrier blocks is greater than the pilot ratio of the communication subcarrier blocks.

[0056] Among them, a linear frequency modulated carrier signal refers to a signal whose frequency changes linearly with time. A set of orthogonal linear frequency modulated carrier signals can be represented by the following formula:

[0057] (1)

[0058] Where N is a positive integer, This represents the nth subcarrier signal in the linear frequency modulated carrier signal; T represents the preset duration of the linear frequency modulated carrier signal. This indicates the linear frequency modulation rate.

[0059] Compared to linear exponential waveforms, linear frequency modulated (LFM) carrier signals have a wider bandwidth. Therefore, using LFM carrier signals for signal transmission helps to resist adverse effects such as multipath fading, Doppler shift, and sudden interference, thereby improving the robustness of the signal transmission system.

[0060] In this embodiment of the invention, the linear frequency modulated carrier signal is divided into multiple subcarrier blocks, which are further divided into communication subcarrier blocks and navigation subcarrier blocks according to functional requirements. The communication subcarrier blocks are used to carry communication data, and the navigation subcarrier blocks are used to carry navigation data. Using a set of orthogonal linear frequency modulated carrier signals for data transmission, i.e., using Orthogonal Chirp Division Multiplexing (OCDM) technology, helps reduce co-channel interference and effectively resists adverse effects such as multipath fading and sudden interference. Furthermore, dividing the data into different subcarrier blocks for classified data transmission enables integrated transmission of communication and navigation data within a unified signal framework, thus improving spectrum utilization efficiency.

[0061] As an example, a set of linear frequency modulated subcarriers with a total number of K subcarriers is divided into B subcarrier blocks, each subcarrier block including The set of subcarriers of the b-th subcarrier block in a set of consecutive subcarriers can be defined as follows:

[0062] (2)

[0063] A pilot signal is a reference signal in a communication and navigation system, primarily used by the receiver for critical tasks such as signal synchronization, channel estimation, and interference suppression. It typically does not carry user data for communication or navigation functions, but rather supports efficient data transmission. In navigation data transmission, pilot data aids in ranging and positioning, enhancing signal tracking and positioning performance; therefore, a higher proportion of pilot data resources is allocated to the navigation subcarrier block. In communication data transmission, pilot data helps in fast and reliable data demodulation, improving the efficiency of effective data transmission; therefore, a lower proportion of pilot data resources is allocated. Optionally, the pilot ratio in the communication subcarrier block can be 5% to 10%, and the pilot ratio in the navigation subcarrier block can be 20% to 35%. By rationally allocating pilot resources in the navigation and communication subcarrier blocks, a dynamic balance between communication efficiency and navigation accuracy is achieved.

[0064] Step 13: Modulate the preset first pilot data and the navigation data sequence onto the subcarrier signal in the navigation subcarrier block, modulate the preset second pilot data and the communication data sequence onto the subcarrier signal in the communication subcarrier block, and superimpose the modulated navigation subcarrier block signal and the modulated communication subcarrier block signal to obtain the transmission signal.

[0065] The preset first pilot data refers to pre-set data used for navigation, ranging, and positioning, such as pilot components of GPS L1C and pilot components of BeiDou B1C. The preset second pilot data refers to signals generated within a preset framework, such as reference signals in 4G / 5G and preambles in Wi-Fi. The specific parameters can be modulated according to actual conditions, and this invention does not limit this. The pilot data includes multiple pilot symbols.

[0066] As an example, the b-th subcarrier block signal in the transmitted signal can be represented by the following formula:

[0067] (3)

[0068] in, This represents the b-th subcarrier block signal in the transmitted signal; N represents the number of subcarriers in a subcarrier block. The pilot ratio of the b-th subcarrier block in the transmitted signal is determined according to the type of subcarrier block; This represents the i-th pilot symbol carried in the b-th subcarrier block. In a linear frequency modulated carrier signal, the ( )th ... ) subcarriers; This represents the j-th data symbol carried in the b-th subcarrier block. When the b-th subcarrier block is a navigation subcarrier block, this data symbol is a navigation data symbol; when the b-th subcarrier block is a communication subcarrier block, this data symbol is a communication data symbol. In a linear frequency modulated carrier signal, the ( )th ... There are 10 subcarriers. And as can be seen from formula (3), a subcarrier signal carries a pilot symbol or a data symbol.

[0069] In addition, to unify the signal structure of communication and navigation subcarrier blocks, it can be expressed by the following formula. :

[0070] (4)

[0071] in, Indicates the pilot ratio of the communication subcarrier block. Indicates the pilot ratio of the navigation subcarrier block. Used to indicate the type of the b-th subcarrier block, when When the b-th subcarrier block is the navigation subcarrier block, when When the b-th subcarrier block is a communication subcarrier block, using formula (4) helps to automatically select the pilot ratio according to the type of subcarrier block during the signal generation process, thereby improving the efficiency of signal generation and transmission.

[0072] By modulating navigation data and communication data onto the subcarriers of corresponding modules to generate transmission signals, the unified integration of communication and navigation functions at the physical layer and the parallel transmission of communication data and navigation information within the same signal frame are achieved. This solves the problems of resource separation and weak coordination capabilities in traditional communication and navigation systems, and improves the utilization efficiency of spectrum resources.

[0073] Step 14: Send the transmitted signal to the receiving end.

[0074] In summary, this invention provides an integrated communication and navigation signal transmission method based on OCDM. The method involves acquiring a target transmission symbol sequence carrying navigation and communication data, generating a set of orthogonal linear frequency modulated (LFM) carrier signals, wherein these LFM carrier signals are divided into navigation subcarrier blocks and communication subcarrier blocks, with the pilot ratio of the navigation subcarrier blocks being greater than that of the communication subcarrier blocks; modulating a preset first pilot data and the navigation data sequence onto the subcarrier signals in the navigation subcarrier blocks, and modulating a preset second pilot data and the communication data sequence onto the subcarrier signals in the communication subcarrier blocks; then superimposing the modulated navigation subcarrier block signals and the modulated communication subcarrier block signals to obtain a transmission signal; and finally transmitting the transmission signal to the receiving end.

[0075] In the above approach, a set of orthogonal linear frequency modulated carrier signals is divided into communication subcarrier blocks and navigation subcarrier blocks. This enables the integrated transmission of communication and navigation data within a unified signal framework, effectively solving the problems of resource separation, weak coordination, and wasted spectrum resources in traditional communication and navigation systems, and improving spectrum utilization efficiency. At the same time, by using differentiated pilot resource allocation methods, a higher proportion of pilot resources are configured in the navigation subcarrier blocks to improve time and frequency synchronization and positioning accuracy, while data throughput is prioritized in the communication subcarrier blocks. This achieves a dynamic balance between communication efficiency and navigation accuracy, thereby improving the flexibility and scalability of signal transmission.

[0076] Optionally, the transmitted signal includes a modulated navigation subcarrier block signal and a modulated communication subcarrier block signal; the modulated communication subcarrier block signal includes a cyclic prefix portion, a pilot portion, and a communication data payload portion, and the modulated navigation subcarrier block signal includes a cyclic prefix portion, a pilot portion, and a navigation data payload portion.

[0077] Adding a cyclic prefix (CP) helps with data synchronization, resists multipath interference, and thus enhances the accuracy of data transmission.

[0078] As an example, Figure 2 A structural diagram of an inventive signal provided by an embodiment of the present invention is given. Figure 2In the diagram, the horizontal axis represents time, the vertical axis represents frequency, and CP stands for Cyclic Prefix. As shown by the dashed lines, a column forms an ODCM symbol, and columns of these symbols form a continuous OCDM symbol, thus constituting the invention signal. Each OCDM symbol is further divided into multiple subcarrier blocks, each represented by a square. Red squares represent navigation subcarrier blocks, and blue squares represent communication subcarrier blocks. Each subcarrier block contains multiple consecutive subcarriers. The navigation subcarrier block includes a cyclic prefix, a pilot section, and a communication data payload. The pilot section in the modulated navigation subcarrier block carries the first pilot data, and the communication data payload carries the navigation data to be transmitted. The communication subcarrier block signal also includes a cyclic prefix, a pilot section, and a communication data payload. The pilot section in the modulated communication subcarrier block signal carries the second pilot data, and the communication data payload carries the communication data to be transmitted. This signal structure achieves parallel multiplexing of communication and navigation signals in the frequency domain and an integrated expression of signal structure and functional configuration.

[0079] Optionally, step 13 includes:

[0080] Add a function identifier to the subcarrier block; the function identifier is used to distinguish between communication subcarrier blocks and navigation subcarrier blocks.

[0081] Based on the functional identifier, the preset first pilot data and the navigation data sequence are modulated onto the subcarrier signal in the navigation subcarrier block, the preset second pilot data and the communication data sequence are modulated onto the subcarrier signal in the communication subcarrier block, and the modulated navigation subcarrier block signal and the modulated communication subcarrier block signal are superimposed to obtain the transmission signal.

[0082] As an example, after dividing all K subcarriers into B subcarrier blocks, each containing K / B consecutive subcarriers, a function identifier can be assigned to each subcarrier block according to functional requirements. When the subcarrier block is a communication subcarrier block, When the subcarrier block is a navigation subcarrier block, .

[0083] Optionally, step 11 includes:

[0084] Acquire a bit stream to be transmitted, wherein the bit stream to be transmitted includes communication data and navigation data;

[0085] The navigation data in the bit stream to be transmitted is mapped according to a preset first mapping method, and the communication data in the bit stream to be transmitted is mapped according to a preset second mapping method to obtain a target transmission symbol sequence, wherein the order of the second mapping method is greater than the order of the first mapping method.

[0086] The first mapping method includes, but is not limited to, low-order mapping methods such as BPSK and QPSK, which helps improve the accuracy and robustness of navigation data transmission; the second mapping method includes, but is not limited to, high-order mapping methods such as 16QAM and 64QAM, which is beneficial for improving the signal transmission rate. Furthermore, in this embodiment of the invention, [the following can be used] This represents the order of the mapping method used for the transmitted data carried by the b-th subcarrier block in the transmitted signal. Furthermore, since the transmitted signal and the received signal are mutually corresponding, therefore... Similarly, it can represent the order of the mapping method used for the transmitted data carried by the b-th subcarrier block in the received signal.

[0087] Optionally, the method further includes a receiving portion, the receiving portion comprising:

[0088] Step 21: Receive the transmitted signal from the transmitting end to obtain the received signal; the received signal includes a subcarrier block carrying the transmitted data;

[0089] Step 22: Perform matched filtering on the received signal to restore the target transmission symbol sequence.

[0090] The received signal corresponds to the transmitted signal and includes data-carrying subcarrier blocks, namely navigation subcarrier blocks carrying navigation data and communication subcarrier blocks carrying communication data. Furthermore, the number of subcarrier blocks and the number of subcarriers in the received signal are the same as those in the transmitted signal and the transmitted signal.

[0091] Specifically, the receiver can perform matched filtering using the following formula to recover the target transmitted symbol sequence carried in the linear frequency modulated carrier signal:

[0092] (5)

[0093] in, This represents the m-th symbol in the target transmitted symbol sequence recovered by the receiving end; This indicates the duration of the preset linear frequency modulated carrier signal. Indicates the received signal; Describes the m-th matched filter, “” indicates complex conjugate, that is, each matched filter corresponds one-to-one with the subcarrier signal described in the aforementioned formula (1), and presents a one-to-one conjugate relationship.

[0094] Optionally, the method further includes:

[0095] Step 231: Construct a discrete-time model of signal transmission according to the following formula:

[0096] (6)

[0097] in, The impulse response represents the signal transmission; L represents the effective multipath number determined by the receiver. For the first Path complex gain, For the first Road delay, It is a unit impulse function. The sampling time;

[0098] Step 232: Calculate the gain of each subcarrier in the received signal according to the following formula:

[0099] (7)

[0100] in, This represents the gain of the k-th subcarrier in the received signal in the frequency domain, where K is the total number of subcarriers in the received signal. It is the symbol for imaginary numbers.

[0101] It is understandable that signal transmission environments are often complex, especially in scenarios with significant multipath conditions such as at sea, in the air, or in densely populated urban areas. Therefore, the transmitted signal needs to adapt to frequency-selective aging channels. Based on this, a discrete time-domain model as shown in Equation (6) and a subcarrier gain calculation formula as shown in Equation (7) are constructed.

[0102] The effective multipath number refers to the number of multipath components that have a significant impact on the received signal in a real environment. For multiple effective multipath components, the first Path complex gain, For the corresponding first Path delay. Effective multipath number and the first... The path complex gain can be obtained by measurement at the receiving end, and this invention does not limit it.

[0103] The channel modeling and gain modeling described above can provide input for subsequent bit error rate estimation and power allocation optimization, thereby improving the robustness of the signal transmission system.

[0104] Optionally, the method further includes:

[0105] Step 241: Calculate the pilot-related navigation error term of the received signal according to the following formula:

[0106] (8)

[0107] in, B represents the pilot-related navigation error term of the received signal; B represents the number of subcarrier blocks in the received signal. Used to indicate the type of the b-th subcarrier block, when When the b-th subcarrier block is the navigation subcarrier block, when At that time, the b-th subcarrier block is a communication subcarrier block; The pilot ratio of the b-th subcarrier block is represented by N, and N represents the number of subcarriers in a subcarrier block.

[0108] Step 242: Calculate the navigation data error within each navigation subcarrier block according to the following formula:

[0109] (9)

[0110] in, This represents the navigation data error of the b-th subcarrier block in the received signal. When the b-th subcarrier block is a communication subcarrier block, the navigation data error is not calculated. This represents the standard deviation of the power of each subcarrier in the b-th subcarrier block of the received signal. This indicates the phase jitter level of the b-th subcarrier block; This indicates the order of the mapping method used for the transmitted data carried by the b-th subcarrier block in the received signal. express The minimum constellation spacing corresponding to the mapping method of order; and These are empirical weighting coefficients;

[0111] Step 243: Calculate the average navigation data error of the received signal based on the navigation data error within each subcarrier block;

[0112] Step 244: Based on the pilot-related navigation error term and the average navigation data error, calculate the navigation data transmission accuracy of the received signal according to a preset weighting factor.

[0113] Regarding formula (8), " " represents the total number of pilot symbols in all navigation submodules in the received signal. The accuracy of navigation data is affected by the pilots. The more pilot data in the navigation submodules in the received signal, the stronger the synchronization and tracking performance during signal transmission. Therefore, the pilot-related navigation error term can be defined as being inversely proportional to the total number of pilots, i.e., the pilot-related navigation error term can be measured using formula (8).

[0114] Regarding formula (9) It is the minimum constellation spacing corresponding to the data transmission mapping method, and The complexity is related to the order of the mapping; and Inversely proportional, This represents the average power of each subcarrier in the b-th subcarrier block of the received signal; and Adjustments can be made based on actual conditions. In addition to the influence of pilot signals, the recovery of navigation data at the receiver is also affected by factors such as channel fluctuations, modulation scheme selection, and uneven signal power distribution. Therefore, the jitter error of the navigation subcarrier block, i.e., the navigation data error within the navigation subcarrier block, can be calculated by using the power of each subcarrier block in the received signal measured at the receiver, the order of the mapping scheme corresponding to the transmitted data carried in the subcarrier block, and the minimum constellation spacing corresponding to that order.

[0115] Regarding step 243, the average navigation data error of the received signal can be calculated using the following formula:

[0116] (10)

[0117] in, The average navigation data error of the received signal is represented by ; other symbols can be referred to the aforementioned formulas (2)-(9), which will not be elaborated here.

[0118] Regarding step 244, the accuracy of navigation data transmission of the received signal can be calculated as follows:

[0119] (11)

[0120] in, Indicates the accuracy of navigation data transmission of received signals; This represents the pilot-related navigation error term of the received signal calculated in step 241. This represents the average navigation data error of the received signal calculated in step 243; , which is a preset weighting factor used to reflect the relative importance of pilot allocation and navigation data quality in the overall navigation performance.

[0121] Calculating navigation accuracy using the methods described in steps 241-244 helps to quantify the impact of different pilot ratios, resource allocation structures, and modulation schemes on navigation accuracy, providing theoretical support for achieving a balanced optimization of communication and navigation fusion capabilities in subsequent system design.

[0122] Optionally, the method further includes:

[0123] Step 25: Calculate the overall communication rate based on the received signal using the following formula:

[0124] (12)

[0125] in, B represents the overall communication rate; B represents the number of subcarrier blocks in the received signal, and N represents the number of subcarriers in a subcarrier block. This represents the pilot ratio of the b-th subcarrier block in the received signal. This indicates the number of subcarriers used for data transmission in a subcarrier block; This indicates the order of the mapping method used for the transmitted data carried by the b-th subcarrier block in the received signal.

[0126] The overall communication rate reflects the direct impact of the pilot ratio on the system throughput performance. Based on the overall communication efficiency, the pilot ratio of the navigation subcarrier block and the pilot ratio of the communication subcarrier block can be flexibly configured. This allows for flexible switching between "high-precision navigation" and "high-efficiency communication" as needed, enhancing the adaptive task scheduling capability and resource optimization design capability of integrated communication and navigation transmission.

[0127] Optionally, the method further includes:

[0128] Step 261: Calculate the bit error rate of each subcarrier according to the following formula:

[0129] (13)

[0130] in, This represents the bit error rate of the k-th subcarrier in the b-th subcarrier block of the received signal; This indicates the order of the mapping method used for the transmitted data carried by the b-th subcarrier block in the received signal; This represents the channel gain in the frequency domain of the k-th subcarrier within the b-th subcarrier block of the received signal. This represents the transmit power corresponding to the k-th subcarrier in the b-th subcarrier block of the received signal. The channel noise power spectral density; It is a Gaussian Q-function;

[0131] Step 262: Calculate the average bit error rate based on the bit error rate of each subcarrier to obtain the overall bit error rate of transmitting the received signal.

[0132] Regarding formula 261, It can be calculated at the receiving end. The transmit power allocated by the transmitter to the corresponding subcarrier; The channel noise power spectral density can be determined based on the signal transmission environment, such as urban airspace or marine environments. This is a Gaussian Q-function used to describe the probability that a constellation point falls into the erroneous decision region.

[0133] Regarding step 262, the average bit error rate of each subcarrier block can be calculated using the following formula:

[0134] (14)

[0135] in, This represents the average bit error rate of the b-th subcarrier block in the received signal; The pilot ratio of the b-th subcarrier block of the received signal is represented by N, where N represents the number of subcarriers in a subcarrier block. Let represent the set of all subcarriers carrying transmitted data in the b-th subcarrier block of the received signal, excluding subcarriers carrying pilot data. The cardinality of this set is . ; This represents the bit error rate of the subcarrier calculated in step 261.

[0136] Based on the above formulas (13) and (14), the overall bit error rate of the received signal can be expressed by the following formula:

[0137] (15)

[0138] in, This represents the overall bit error rate of the received signal; Indicates the number of subcarrier blocks in the received signal. This represents the pilot ratio of the b-th subcarrier block of the received signal. Indicates the number of subcarriers in a subcarrier block; This indicates the order of the mapping method used for the transmitted data carried by the b-th subcarrier block in the received signal.

[0139] Through steps 261-262, in practical engineering implementation, the channel gain can be adjusted at the receiving end. The real-time estimation results are based on the prediction. Adjust the transmit power Or switch dynamically according to channel conditions. The mapping order is adjusted to reduce the bit error rate and improve link robustness under harsh channel conditions.

[0140] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0141] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. A communication and navigation integrated signal transmission method based on OCDM, characterized in that, The method includes a sending portion, the sending portion comprising: Step 11, obtain the target transmission symbol sequence; the target transmission symbol sequence includes a navigation data sequence and a communication data sequence; Step 12: Generate a set of orthogonal linear frequency modulated carrier signals; wherein the linear frequency modulated carrier signals include multiple subcarrier signals, the subcarrier signals are divided into multiple subcarrier blocks, the subcarrier blocks include navigation subcarrier blocks and communication subcarrier blocks; the pilot ratio of the navigation subcarrier blocks is greater than the pilot ratio of the communication subcarrier blocks; Step 13: Modulate the preset first pilot data and the navigation data sequence onto the subcarrier signal in the navigation subcarrier block, modulate the preset second pilot data and the communication data sequence onto the subcarrier signal in the communication subcarrier block, and superimpose the modulated navigation subcarrier block signal and the modulated communication subcarrier block signal to obtain the transmission signal; Step 14: Send the transmitted signal to the receiving end.

2. The method according to claim 1, characterized in that, The transmitted signal includes a modulated navigation subcarrier block signal and a modulated communication subcarrier block signal; the modulated communication subcarrier block signal includes a cyclic prefix part, a pilot part, and a communication data payload part, and the modulated navigation subcarrier block signal includes a cyclic prefix part, a pilot part, and a navigation data payload part.

3. The method according to claim 1, characterized in that, The pilot ratio of the communication subcarrier block is 5% to 10%, and the pilot ratio of the navigation subcarrier block is 20% to 35%.

4. The method according to claim 1, characterized in that, Step 13 includes: Add a function identifier to the subcarrier block; the function identifier is used to distinguish between communication subcarrier blocks and navigation subcarrier blocks. Based on the functional identifier, the preset first pilot data and the navigation data sequence are modulated onto the subcarrier signal in the navigation subcarrier block, the preset second pilot data and the communication data sequence are modulated onto the subcarrier signal in the communication subcarrier block, and the modulated navigation subcarrier block signal and the modulated communication subcarrier block signal are superimposed to obtain the transmission signal.

5. The method according to claim 1, characterized in that, Step 11 includes: Acquire a bit stream to be transmitted, wherein the bit stream to be transmitted includes communication data and navigation data; The navigation data in the bit stream to be transmitted is mapped according to a preset first mapping method, and the communication data in the bit stream to be transmitted is mapped according to a preset second mapping method to obtain a target transmission symbol sequence, wherein the order of the second mapping method is greater than the order of the first mapping method.

6. The method according to claim 1, characterized in that, The method further includes a receiving portion, the receiving portion comprising: Step 21: Receive the transmitted signal from the transmitting end to obtain the received signal; the received signal includes a subcarrier block carrying the transmitted data; Step 22: Perform matched filtering on the received signal to restore the target transmission symbol sequence.

7. The method according to claim 6, characterized in that, The method further includes: Step 231: Construct a discrete-time model of signal transmission according to the following formula: ， in, The impulse response represents the signal transmission; L represents the effective multipath number determined by the receiver. For the first Path complex gain, For the first Road delay, It is a unit impulse function. The sampling point time; Step 232: Calculate the gain of each subcarrier in the received signal according to the following formula: ， in, This represents the gain of the k-th subcarrier in the received signal in the frequency domain, where K is the total number of subcarriers in the received signal.

8. The method according to claim 7, characterized in that, The method further includes: Step 241: Calculate the pilot-related navigation error term of the received signal according to the following formula: ， in, B represents the pilot-related navigation error term of the received signal; B represents the number of subcarrier blocks in the received signal. Used to indicate the type of the b-th subcarrier block, when When the b-th subcarrier block is the navigation subcarrier block, when At that time, the b-th subcarrier block is a communication subcarrier block; The pilot ratio of the b-th subcarrier block is represented by N, and N represents the number of subcarriers in a subcarrier block. Step 242: Calculate the navigation data error within each navigation subcarrier block according to the following formula: ， in, This represents the navigation data error of the b-th subcarrier block in the received signal. When the b-th subcarrier block is a communication subcarrier block, the navigation data error is not calculated. This represents the standard deviation of the power of each subcarrier in the b-th subcarrier block of the received signal. This indicates the phase jitter level of the b-th subcarrier block; This indicates the order of the mapping method used for the transmitted data carried by the b-th subcarrier block in the received signal. express The minimum constellation spacing corresponding to the mapping method of order; and These are empirical weighting coefficients; Step 243: Calculate the average navigation data error in the received signal based on the navigation data error within each subcarrier block; Step 244: Based on the pilot-related navigation error term and the average navigation data error, calculate the navigation data transmission accuracy of the received signal according to a preset weighting factor.

9. The method according to claim 7, characterized in that, The method further includes: Step 25: Calculate the overall communication rate based on the received signal using the following formula: ， in, B represents the overall communication rate; B represents the number of subcarrier blocks in the received signal, and N represents the number of subcarriers in a subcarrier block. This represents the pilot ratio of the b-th subcarrier block in the received signal. This indicates the number of subcarriers used for data transmission in a subcarrier block; This indicates the order of the mapping method used for the transmitted data carried by the b-th subcarrier block in the received signal.

10. The method according to claim 7, characterized in that, The method further includes: Step 261: Calculate the bit error rate of each subcarrier according to the following formula: ， in, This represents the bit error rate of the k-th subcarrier in the b-th subcarrier block of the received signal; This indicates the order of the mapping method used for the transmitted data carried by the b-th subcarrier block in the received signal; This represents the channel gain in the frequency domain of the k-th subcarrier within the b-th subcarrier block of the received signal. This represents the transmit power corresponding to the k-th subcarrier in the b-th subcarrier block of the received signal. The channel noise power spectral density; It is a Gaussian Q-function; Step 262: Calculate the average bit error rate based on the bit error rate of each subcarrier to obtain the overall bit error rate of transmitting the received signal.

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