A method and apparatus for generating an ultra-wideband navigation signal based on a linear frequency modulation spread code

Abstract

The application relates to a method and device for generating an ultra-wideband navigation signal based on a linear frequency modulation spread code, and belongs to the technical field of satellite navigation. The method comprises the following steps: generating a linear frequency modulation spread code of a data / pilot branch by using a phase quantization model which satisfies a cooperative optimization constraint of generation complexity and sidelobe suppression performance; generating a pseudo-random spread code of the data / pilot branch; generating a data code containing navigation messages; generating a digital baseband signal of a pilot branch according to the pseudo-random spread code and the linear frequency modulation spread code of the pilot branch, and performing digital-to-analog conversion; generating a digital baseband signal of a data branch according to the data code, the pseudo-random spread code and the linear frequency modulation spread code of the data branch, and performing digital-to-analog conversion; and generating a complete ultra-wideband navigation signal according to the analog baseband signals of the data / pilot and a radio frequency carrier. The method can greatly reduce the complexity of generating an ultra-wideband navigation signal, and provides key technical support for the application of the ultra-wideband navigation signal.

Description

Technical Field

[0001] This application relates to the field of satellite navigation technology, and in particular to a method and apparatus for generating ultra-wideband navigation signals based on linear frequency modulation spreading codes. Background Technology

[0002] As the core of a nation's integrated positioning, navigation, and timing system, satellite navigation systems play a crucial role in providing a global, all-weather spatiotemporal reference. However, their signals have weak ground power and are highly susceptible to various types of interference, necessitating enhanced anti-interference performance in complex adversarial scenarios. With the increasing maturity of broadband spaceborne radio frequency amplifiers and antenna technology, broadcasting ultra-wideband navigation signals in the hundreds of megabits per second range has gradually become possible. These signals, with their lower power spectral density, stronger anti-interference capabilities, and higher measurement accuracy, have become the core development direction for the signal design of next-generation satellite navigation systems.

[0003] Traditional navigation signals mainly use direct sequence spread spectrum modulation, which can meet the basic measurement and anti-interference requirements, but has significant bottlenecks in ultra-wideband scenarios: the widening of signal bandwidth inevitably leads to a surge in spread spectrum code rate, and high code rate will exacerbate the code Doppler effect in dynamic scenarios, seriously deteriorating the receiving performance. At the same time, this modulation method has low utilization of spectrum resources and is difficult to adapt to the bandwidth requirements of hundreds of megabits.

[0004] Linear frequency modulation (LFM), widely used in radar technology, is an efficient ultra-wideband modulation scheme with stronger Doppler shift tolerance and higher ranging potential. Combining it with pseudo-random spreading codes to form a pseudo-code phase modulation-LFM composite modulation signal can further improve Doppler resistance and ranging accuracy. However, the LFM waveform relies on a second-order voltage-controlled oscillator for generation, significantly increasing the complexity of signal generation and limiting its application in ultra-wideband navigation scenarios. Summary of the Invention

[0005] Therefore, it is necessary to provide a method and apparatus for generating ultra-wideband navigation signals based on linear frequency modulation spreading codes to address the technical problem of high complexity in generating linear frequency modulation waveforms during the generation of pseudo-code phase modulation-linear frequency modulation ultra-wideband navigation signals.

[0006] A method for generating ultra-wideband navigation signals based on linear frequency modulation spreading codes, the method comprising:

[0007] Driven by the generation clock, the phase of the linear frequency modulation (LFM) spreading code is calculated. Using a phase quantization model that satisfies the co-optimization constraints of generation complexity and sidelobe suppression performance, the LFM spreading code phase is quantized into a fixed angle. Based on the quantized LFM spreading code phase angle, the LFM spreading codes for the data branch and pilot branch are generated.

[0008] Driven by the generation clock, the pseudo-random spreading code phase is calculated and generated, and the pseudo-random spreading codes for the data branch and pilot branch are generated based on the pseudo-random spreading code phase.

[0009] Generate a data code containing navigation message data based on navigation message information and message encoding scheme;

[0010] Based on the pseudo-random spreading code and the linear frequency modulation spreading code of the pilot branch, the digital baseband signal of the pilot branch is generated, and the analog baseband signal of the pilot branch is generated through digital-to-analog conversion.

[0011] Based on the data code, the pseudo-random spreading code of the data branch, and the linear frequency modulation spreading code of the data branch, the digital baseband signal of the data branch is generated, and the analog baseband signal of the data branch is generated through digital-to-analog conversion.

[0012] The radio frequency carrier of the ultra-wideband navigation signal is generated based on the radio frequency and the initial phase of the carrier.

[0013] A complete ultra-wideband navigation signal is generated based on the analog baseband signal of the pilot branch, the analog baseband signal of the data branch, and the radio frequency carrier.

[0014] In one embodiment, driven by the generation clock, the phase of the generated linear frequency modulation spreading code is calculated and expressed as:

[0015] ;

[0016] in, For the first The linear frequency modulation spreading code phase value under each clock cycle, initial value The unit is week; This represents the modulo operation; For linear frequency modulation slope, For signal bandwidth, This represents the signal sampling rate.

[0017] In one embodiment, a phase quantization model that satisfies the synergistic optimization constraints of generation complexity and sidelobe suppression performance is used to quantize the phase of the linear frequency modulation spreading code into a fixed angle, including:

[0018] Using the phase quantization model to... The phase value of the linear frequency modulation spreading code under each clock beat Quantized to a fixed angle, the first... Phase angle of quantized linear frequency modulation spreading code under each clock beat , is represented as:

[0019] ;

[0020] in, To quantify the threshold, From a quantitative perspective, For quantization space, it is determined by the number of quantization bits. Decision, that is Quantization bits The value of satisfies the synergistic optimization constraint between generation complexity and sidelobe suppression performance. Generation complexity is a comprehensive reflection of the operational complexity of phase calculation, the storage capacity of the hardware lookup table, and the hardware resource consumption of the quantization decision logic, and is related to the number of quantization bits. It exhibits an exponential positive correlation, and its quantitative formula is expressed as: , Quantization bit depth The generation complexity is as follows: To normalize the generation complexity; the sidelobe suppression performance is reflected by the peak sidelobe ratio, and its quantification formula is expressed as: , The peak-to-side-lobe ratio, The maximum power density of the main lobe. Let be the maximum power density of the sidelobe; if uniform quantization is used in the phase quantization model, then the th... Individual quantification threshold , No. From a quantitative perspective Taking the average of adjacent quantization thresholds, we have: ,in This is the quantization interval.

[0021] In one embodiment, linear frequency modulation (LFM) spreading codes for the data branch and pilot branch are generated based on the phase angle of the quantized LFM spreading code, including:

[0022] According to the Phase angle of quantized linear frequency modulation spreading code under each clock beat Generate the linear frequency modulation spreading code for the data branch. linear frequency modulation spreading code of pilot branch , respectively represented as:

[0023] .

[0024] In one embodiment, driven by a generation clock, a pseudo-random spreading code phase is calculated, and pseudo-random spreading codes for the data branch and pilot branch are generated based on the pseudo-random spreading code phase, including:

[0025] Driven by the generation clock, the phase of the pseudo-random spreading code is calculated and expressed as:

[0026] ;

[0027] in, For the first The pseudo-random spreading code phase value under each clock tick The code rate of the pseudo-random spreading code. The signal sampling rate;

[0028] according to Pseudo-random spreading codes for generating data branches Pseudo-random spreading codes of pilot branches , respectively represented as:

[0029] ;

[0030] in, and These represent the pseudo-random spread spectrum sequences for the data branch and the pilot branch, respectively.

[0031] In one embodiment, a digital baseband signal for the pilot branch is generated based on the pseudo-random spreading code and the linear frequency modulation spreading code of the pilot branch, and then converted from digital to analog to generate an analog baseband signal for the pilot branch, including:

[0032] Based on the pseudo-random spreading code of the pilot branch linear frequency modulation spreading code of pilot branch The digital baseband signal for generating the pilot branch is represented as:

[0033] ;

[0034] right Performing a digital-to-analog conversion yields the analog baseband signal of the pilot branch, represented as:

[0035] ;

[0036] in, This represents a continuous-time variable.

[0037] In one embodiment, a digital baseband signal for the data branch is generated based on the data code, the pseudo-random spreading code of the data branch, and the linear frequency modulation spreading code of the data branch, and then converted from digital to analog to generate an analog baseband signal for the data branch, including:

[0038] According to the data code Pseudo-random spreading codes for data branches Linear frequency modulation spreading code for data branches The digital baseband signal of the generated data branch is represented as:

[0039] ;

[0040] right Performing digital-to-analog conversion yields the analog baseband signal of the data branch, represented as:

[0041] .

[0042] In one embodiment, the radio frequency carrier for generating the ultra-wideband navigation signal based on the radio frequency and the initial phase of the carrier is represented as:

[0043] ;

[0044] in, For radio frequency, Represents a continuous-time variable. The initial phase of the carrier. This is the symbol for a complex number.

[0045] In one embodiment, a complete ultra-wideband navigation signal is generated based on the analog baseband signal of the pilot branch, the analog baseband signal of the data branch, and the radio frequency carrier, as shown below:

[0046] ;

[0047] in, The analog baseband signal for the data branch consists of a pseudo-random spreading code, a linear frequency modulation spreading code, and a data code containing navigation message data. It is the analog baseband signal of the pilot branch, composed of pseudo-random spreading code and linear frequency modulation spreading code, and does not contain navigation message data.

[0048] An ultra-wideband navigation signal generation device based on linear frequency modulation spreading code, the device comprising:

[0049] The linear frequency modulation spreading code phase calculation module is used to calculate and generate the phase of the linear frequency modulation spreading code under the drive of the generating clock.

[0050] The phase quantization module is used to quantize the phase of the linear frequency modulation spreading code into a fixed angle using a phase quantization model that satisfies the cooperative optimization constraints of generation complexity and sidelobe suppression performance.

[0051] The linear frequency modulation spreading code generation module is used to generate linear frequency modulation spreading codes for the data branch and the pilot branch based on the phase angle of the quantized linear frequency modulation spreading code.

[0052] The pseudo-random spreading code phase calculation module is used to calculate the phase of the generated pseudo-random spreading code under the drive of the generation clock.

[0053] The pseudo-random spreading code generation module is used to generate pseudo-random spreading codes for the data branch and pilot branch based on the phase of the pseudo-random spreading code.

[0054] The data code generation module is used to generate a data code containing navigation message data based on navigation message information and message encoding scheme;

[0055] The first multiplier is used to generate the digital baseband signal of the pilot branch based on the pseudo-random spreading code and the linear frequency modulation spreading code of the pilot branch.

[0056] The first digital-to-analog converter is used to convert the digital baseband signal of the pilot branch into an analog baseband signal of the pilot branch.

[0057] The second multiplier is used to generate the digital baseband signal of the data branch based on the data code, the pseudo-random spreading code of the data branch, and the linear frequency modulation spreading code of the data branch.

[0058] The second digital-to-analog converter is used to convert the digital baseband signal of the data branch into an analog baseband signal of the data branch.

[0059] The carrier generation module is used to generate the radio frequency carrier of the ultra-wideband navigation signal based on the radio frequency and the initial phase of the carrier.

[0060] The ultra-wideband navigation signal generation module is used to generate a complete ultra-wideband navigation signal based on the analog baseband signal of the pilot branch, the analog baseband signal of the data branch, and the radio frequency carrier.

[0061] Compared with existing technologies, the above-mentioned method and apparatus for generating ultra-wideband navigation signals based on linear frequency modulation (LFM) spreading codes have the following advantages: 1. A logic and structure for generating LFM spreading codes based on a phase quantization model are designed. This phase quantization model significantly reduces the computational complexity and hardware implementation complexity of ultra-wideband navigation signal generation while retaining the equivalent spreading capability and constant envelope characteristics of the signal. It is more suitable for engineering requirements in resource-constrained scenarios such as spaceborne systems. Furthermore, since this phase quantization model satisfies the synergistic optimization constraints of generation complexity and sidelobe suppression performance, it can reduce the hardware complexity of signal generation and reduce computational and storage overhead while ensuring that the sidelobe suppression performance does not decrease significantly, thus achieving a balance between signal generation complexity and radiation performance; 2. A pseudo-code phase-linear frequency modulation (LFM) ultra-wideband navigation signal waveform based on LFM spreading codes is designed. This signal inherits the advantages of LFM technology in resisting Doppler frequency shift. Compared with traditional direct sequence spread spectrum signals, it can achieve a more uniform spectral energy distribution under the same bandwidth, and has better anti-interference capability and ranging accuracy. Attached Figure Description

[0062] Figure 1 This is a flowchart illustrating an ultra-wideband navigation signal generation method based on linear frequency modulation spreading code in one embodiment.

[0063] Figure 2This is a constellation diagram for 1-bit quantization of a linear frequency modulation spreading code in one embodiment;

[0064] Figure 3 This is a constellation diagram for 2-bit quantization of a linear frequency modulation spreading code in one embodiment;

[0065] Figure 4 This is a schematic diagram of the waveform of an ultra-wideband navigation signal based on a pseudo-code phase-linear frequency modulation (PLFM) spread spectrum code in one embodiment.

[0066] Figure 5 This is a structural block diagram of an ultra-wideband navigation signal generation device based on linear frequency modulation spreading code in one embodiment. Detailed Implementation

[0067] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0068] In one embodiment, such as Figure 1 As shown, a method for generating ultra-wideband navigation signals based on linear frequency modulation spreading codes is provided, including the following steps:

[0069] Step 1: Driven by the generation clock, calculate and generate the phase of the linear frequency modulation (LFM) spreading code. Using a phase quantization model that satisfies the co-optimization constraints of generation complexity and sidelobe suppression performance, quantize the LFM spreading code phase into a fixed angle. Based on the quantized LFM spreading code phase angle, generate the LFM spreading codes for the data branch and the pilot branch.

[0070] Step 2: Driven by the generation clock, calculate and generate the pseudo-random spreading code phase, and generate the pseudo-random spreading codes for the data branch and pilot branch based on the pseudo-random spreading code phase.

[0071] Step 3: Generate a data code containing navigation message data based on the navigation message information and the message encoding scheme.

[0072] Step 4: Based on the pseudo-random spreading code and the linear frequency modulation spreading code of the pilot branch, generate the digital baseband signal of the pilot branch, and generate the analog baseband signal of the pilot branch through digital-to-analog conversion.

[0073] Step 5: Based on the data code, the pseudo-random spreading code of the data branch, and the linear frequency modulation spreading code of the data branch, generate the digital baseband signal of the data branch, and generate the analog baseband signal of the data branch through digital-to-analog conversion.

[0074] Step 6: Generate the radio frequency carrier of the ultra-wideband navigation signal based on the radio frequency and the initial phase of the carrier.

[0075] Step 7: Generate a complete ultra-wideband navigation signal based on the analog baseband signal of the pilot branch, the analog baseband signal of the data branch, and the radio frequency carrier.

[0076] In the aforementioned method for generating ultra-wideband navigation signals based on linear frequency modulation (LFM) spreading codes, the LFM waveform is quantized using a phase quantization model. This significantly simplifies the generation complexity of ultra-wideband navigation signals while achieving equivalent spreading capability, providing key technical support for their application. Furthermore, since the phase quantization model satisfies the synergistic optimization constraint between generation complexity and sidelobe suppression performance, it can reduce signal generation hardware complexity and computational and storage overhead while ensuring that sidelobe suppression performance does not significantly decrease, achieving a balance between signal generation complexity and radiation performance. Simultaneously, a pseudo-code phase-linear frequency modulation (LFM) ultra-wideband navigation signal waveform based on LFM spreading codes is designed. This signal inherits the advantages of LFM technology in resisting Doppler frequency shift and, compared to traditional direct sequence spread spectrum signals, achieves a more uniform spectral energy distribution within the same bandwidth, resulting in superior anti-interference capability and ranging accuracy.

[0077] In one embodiment, driven by the generation clock, the phase of the generated linear frequency modulation spreading code is calculated and expressed as:

[0078] ;

[0079] in, For the first The linear frequency modulation spreading code phase value under each clock cycle, initial value The unit is week; This represents the modulo operation; For linear frequency modulation slope, For signal bandwidth, This represents the signal sampling rate.

[0080] In one embodiment, a phase quantization model that satisfies the synergistic optimization constraints of generation complexity and sidelobe suppression performance is used to quantize the phase of the linear frequency modulation spreading code into a fixed angle, including:

[0081] Using the phase quantization model to... The phase value of the linear frequency modulation spreading code under each clock beat Quantized to a fixed angle, the first... Phase angle of quantized linear frequency modulation spreading code under each clock beat , is represented as:

[0082] ;

[0083] in, To quantify the threshold, From a quantitative perspective, For quantization space, it is determined by the number of quantization bits. Decision, that is Quantization bits The value of satisfies the synergistic optimization constraint between generation complexity and sidelobe suppression performance. Generation complexity is a comprehensive reflection of the operational complexity of phase calculation, the storage capacity of the hardware lookup table, and the hardware resource consumption of the quantization decision logic, and is related to the number of quantization bits. It exhibits an exponential positive correlation, and its quantitative formula is expressed as: , Quantization bit depth The generation complexity is as follows: To normalize the generation complexity; sidelobe suppression performance is reflected by the peak-to-sidelobe ratio. In scenarios with limited on-board spectrum resources, good sidelobe suppression performance is required to ensure on-board electromagnetic compatibility. Its quantification formula is expressed as: , The peak-to-side-lobe ratio, The maximum power density of the main lobe. Let be the maximum power density of the sidelobe. If the phase quantization model uses uniform quantization, then the ... Individual quantification threshold , No. From a quantitative perspective Taking the average of adjacent quantization thresholds, we have: ,in This is the quantization interval.

[0084] It should be understood that different values ​​of quantization bits directly affect the sidelobe suppression performance and generation complexity of ultra-wideband navigation signals. Specifically, when When taking 1, Approximately -11.5dB. for At this point, the quantized linear frequency modulation spreading code is a dual-level code, and its sidelobe suppression performance meets the basic engineering requirements; when When taking 2, Approximately -16.5dB. for At this point, the quantized linear frequency modulation spreading code is a four-level code, which improves both generation complexity and sidelobe suppression performance compared to 1-bit quantization; when hour, , At this point, the improvement in sidelobe suppression is not significant, but it will significantly increase the onboard hardware resource overhead and computational complexity. Therefore, in the ultra-wideband navigation signal generation scenario of this application, the typical value of the quantization bit depth is 1 or 2. For example, as shown... Figure 2As shown, if the quantization bit depth is 1 (i.e., 1-bit quantization), then the quantization space is 4, the quantization threshold G = [0, 1 / 4, 1 / 2, 3 / 4, 1], and the quantization angle W = [1 / 8, 3 / 8, 5 / 8, 7 / 8]. Figure 3 As shown, if the quantization bit depth is 2, i.e., 2-bit quantization is used, then the quantization space is 8, the quantization threshold G=[0,1 / 8,2 / 8,3 / 8,4 / 8,5 / 8,6 / 8,7 / 8,1] and the quantization angle W=[1 / 16, 3 / 16, 5 / 16, 7 / 16, 9 / 16, 11 / 16, 13 / 16,15 / 16].

[0085] In one embodiment, linear frequency modulation (LFM) spreading codes for the data branch and pilot branch are generated based on the phase angle of the quantized LFM spreading code, including:

[0086] According to the Phase angle of quantized linear frequency modulation spreading code under each clock beat Generate the linear frequency modulation spreading code for the data branch. linear frequency modulation spreading code of pilot branch , respectively represented as:

[0087] .

[0088] In one embodiment, driven by a generation clock, a pseudo-random spreading code phase is calculated, and pseudo-random spreading codes for the data branch and pilot branch are generated based on the pseudo-random spreading code phase, including:

[0089] Driven by the generation clock, the phase of the pseudo-random spreading code is calculated and expressed as:

[0090] ;

[0091] in, For the first The pseudo-random spreading code phase value under each clock tick The code rate of the pseudo-random spreading code;

[0092] according to Pseudo-random spreading codes for generating data branches Pseudo-random spreading codes of pilot branches , respectively represented as:

[0093] ;

[0094] in, and These represent the pseudo-random spread spectrum sequences for the data branch and the pilot branch, respectively.

[0095] In one embodiment, a digital baseband signal for the pilot branch is generated based on the pseudo-random spreading code and the linear frequency modulation spreading code of the pilot branch, and then converted from digital to analog to generate an analog baseband signal for the pilot branch, including:

[0096] Based on the pseudo-random spreading code of the pilot branch linear frequency modulation spreading code of pilot branch The digital baseband signal for generating the pilot branch is represented as:

[0097] ;

[0098] right Performing a digital-to-analog conversion yields the analog baseband signal of the pilot branch, represented as:

[0099] ;

[0100] in, This represents a continuous-time variable.

[0101] In one embodiment, a digital baseband signal for the data branch is generated based on the data code, the pseudo-random spreading code of the data branch, and the linear frequency modulation spreading code of the data branch, and then converted from digital to analog to generate an analog baseband signal for the data branch, including:

[0102] According to the data code Pseudo-random spreading codes for data branches Linear frequency modulation spreading code for data branches The digital baseband signal of the generated data branch is represented as:

[0103] ;

[0104] right Performing digital-to-analog conversion yields the analog baseband signal of the data branch, represented as:

[0105] .

[0106] In one embodiment, the radio frequency carrier for generating the ultra-wideband navigation signal based on the radio frequency and the initial phase of the carrier is represented as:

[0107] ;

[0108] in, For radio frequency, Represents a continuous-time variable. The initial phase of the carrier. This is the symbol for a complex number.

[0109] In one embodiment, a complete ultra-wideband navigation signal is generated based on the analog baseband signal of the pilot branch, the analog baseband signal of the data branch, and the radio frequency carrier, as shown below:

[0110] ;

[0111] in, The analog baseband signal for the data branch consists of a pseudo-random spreading code, a linear frequency modulation spreading code, and a data code containing navigation message data. It is the analog baseband signal of the pilot branch, composed of pseudo-random spreading code and linear frequency modulation spreading code, and does not contain navigation message data.

[0112] It should be understood that the final generated ultra-wideband navigation signal waveform based on the pseudo-code phase-linear frequency modulation (LFM) spreading code is as follows: Figure 4 As shown, the ultra-wideband navigation signal waveform adopts a pseudo-code phase modulation-linear frequency modulation system, consisting of four parts: pseudo-random spreading code, linear frequency modulation spreading code, radio frequency carrier, and navigation message data. Its baseband expression is denoted as:

[0113] ;

[0114] in, For navigation message data, and These are the pseudo-random spreading codes for the data branch and the pilot branch, respectively. and These are the linear frequency modulation spreading codes for the data branch and the pilot branch, respectively. The symbol is for a complex number. The navigation baseband signal is up-converted to an RF frequency by a mixer and transmitted; its transmitted signal expression is denoted as: .

[0115] In one embodiment, such as Figure 5 As shown, an ultra-wideband navigation signal generation device based on linear frequency modulation spreading code is provided, comprising:

[0116] The linear frequency modulation spreading code phase calculation module is used to calculate and generate the phase of the linear frequency modulation spreading code under the drive of the generating clock.

[0117] The phase quantization module is used to quantize the phase of the linear frequency modulation spreading code into a fixed angle using a phase quantization model that satisfies the cooperative optimization constraints of generation complexity and sidelobe suppression performance.

[0118] The linear frequency modulation spreading code generation module is used to generate linear frequency modulation spreading codes for the data branch and the pilot branch based on the phase angle of the quantized linear frequency modulation spreading code.

[0119] The pseudo-random spreading code phase calculation module is used to calculate the phase of the generated pseudo-random spreading code under the drive of the generation clock.

[0120] The pseudo-random spreading code generation module is used to generate pseudo-random spreading codes for the data branch and pilot branch based on the phase of the pseudo-random spreading code.

[0121] The data code generation module is used to generate a data code containing navigation message data based on navigation message information and message encoding scheme;

[0122] The first multiplier is used to generate the digital baseband signal of the pilot branch based on the pseudo-random spreading code and the linear frequency modulation spreading code of the pilot branch.

[0123] The first digital-to-analog converter is used to convert the digital baseband signal of the pilot branch into an analog baseband signal of the pilot branch.

[0124] The second multiplier is used to generate the digital baseband signal of the data branch based on the data code, the pseudo-random spreading code of the data branch, and the linear frequency modulation spreading code of the data branch.

[0125] The second digital-to-analog converter is used to convert the digital baseband signal of the data branch into an analog baseband signal of the data branch.

[0126] The carrier generation module is used to generate the radio frequency carrier of the ultra-wideband navigation signal based on the radio frequency and the initial phase of the carrier.

[0127] The ultra-wideband navigation signal generation module is used to generate a complete ultra-wideband navigation signal based on the analog baseband signal of the pilot branch, the analog baseband signal of the data branch, and the radio frequency carrier.

[0128] Specific limitations regarding the ultra-wideband navigation signal generation device based on linear frequency modulation (LFM) spreading codes can be found in the limitations of the ultra-wideband navigation signal generation method based on LFM spreading codes described above, and will not be repeated here. Each module in the aforementioned ultra-wideband navigation signal generation device based on LFM spreading codes can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in hardware or independently of the processor in a computer device, or stored in software in the memory of a computer device, so that the processor can call and execute the corresponding operations of each module.

[0129] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0130] The above embodiments are merely illustrative of several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application.

Claims

1. A method for generating ultra-wideband navigation signals based on linear frequency modulation spreading codes, characterized in that, include: Driven by the generation clock, the phase of the linear frequency modulation spreading code is calculated. Using a phase quantization model that satisfies the cooperative optimization constraints of generation complexity and sidelobe suppression performance, the phase of the linear frequency modulation spreading code is quantized into a fixed angle. Based on the quantized phase angle of the linear frequency modulation spreading code, the linear frequency modulation spreading codes of the data branch and the pilot branch are generated. Driven by the generation clock, the pseudo-random spreading code phase is calculated and generated, and the pseudo-random spreading codes for the data branch and pilot branch are generated according to the pseudo-random spreading code phase. Generate a data code containing navigation message data based on navigation message information and message encoding scheme; Based on the pseudo-random spreading code and the linear frequency modulation spreading code of the pilot branch, the digital baseband signal of the pilot branch is generated, and the analog baseband signal of the pilot branch is generated through digital-to-analog conversion. Based on the data code, the pseudo-random spreading code of the data branch, and the linear frequency modulation spreading code of the data branch, the digital baseband signal of the data branch is generated, and the analog baseband signal of the data branch is generated through digital-to-analog conversion. The radio frequency carrier of the ultra-wideband navigation signal is generated based on the radio frequency and the initial phase of the carrier. Based on the analog baseband signal of the pilot branch, the analog baseband signal of the data branch, and the radio frequency carrier, a complete ultra-wideband navigation signal is generated. Specifically, a phase quantization model that satisfies the synergistic optimization constraints of generation complexity and sidelobe suppression performance is used to quantize the phase of the linear frequency modulated spreading code into a fixed angle, including: Using the phase quantization model to... The phase value of the linear frequency modulation spreading code under each clock beat Quantized to a fixed angle, the first... Phase angle of quantized linear frequency modulation spreading code under each clock beat , is represented as: ； in, To quantify the threshold, From a quantitative perspective, For quantization space, it is determined by the number of quantization bits. Decision, that is The quantization bits The value of satisfies the synergistic optimization constraint between generation complexity and sidelobe suppression performance. Generation complexity is a comprehensive reflection of the operational complexity of phase calculation, the storage capacity of the hardware lookup table, and the hardware resource consumption of the quantization decision logic, and is related to the number of quantization bits. It exhibits an exponential positive correlation, and its quantitative formula is expressed as: , Quantization bit depth The generation complexity is as follows: To normalize the generation complexity; the sidelobe suppression performance is reflected by the peak sidelobe ratio, and its quantification formula is expressed as: , The peak-to-side-lobe ratio, The maximum power density of the main lobe. The maximum power density of the sidelobe; the phase quantization model adopts uniform quantization, then the... Individual quantification threshold , No. From a quantitative perspective Taking the average of adjacent quantization thresholds, we have: ,in This is the quantization interval.

2. The method for generating ultra-wideband navigation signals based on linear frequency modulation spreading codes according to claim 1, characterized in that, Driven by the generating clock, the phase of the generated linear frequency modulation spreading code is calculated and expressed as: ； in, For the first The linear frequency modulation spreading code phase value under each clock cycle, initial value The unit is week; This represents the modulo operation; For linear frequency modulation slope, For signal bandwidth, This represents the signal sampling rate.

3. The method for generating ultra-wideband navigation signals based on linear frequency modulation spreading codes according to claim 1, characterized in that, Based on the phase angle of the quantized linear frequency modulation (LFM) spreading code, LFM spreading codes for the data branch and pilot branch are generated, including: According to the Phase angle of quantized linear frequency modulation spreading code under each clock beat Generate the linear frequency modulation spreading code for the data branch. linear frequency modulation spreading code of pilot branch , respectively represented as: 。 4. The method for generating ultra-wideband navigation signals based on linear frequency modulation spreading codes according to claim 3, characterized in that, Driven by the generation clock, the pseudo-random spreading code phase is calculated, and pseudo-random spreading codes for the data branch and pilot branch are generated based on the pseudo-random spreading code phase, including: Driven by the generation clock, the phase of the pseudo-random spreading code is calculated and expressed as: ； in, For the first The pseudo-random spreading code phase value under each clock tick The code rate of the pseudo-random spreading code. The signal sampling rate; according to Pseudo-random spreading codes for generating data branches Pseudo-random spreading codes of pilot branches , respectively represented as: ； in, and These represent the pseudo-random spread spectrum sequences for the data branch and the pilot branch, respectively.

5. The method for generating ultra-wideband navigation signals based on linear frequency modulation spreading codes according to claim 4, characterized in that, Based on the pseudo-random spreading code and the linear frequency modulation spreading code of the pilot branch, the digital baseband signal of the pilot branch is generated, and then converted from digital to analog to generate the analog baseband signal of the pilot branch, including: Based on the pseudo-random spreading code of the pilot branch linear frequency modulation spreading code of pilot branch The digital baseband signal for generating the pilot branch is represented as: ； right Performing a digital-to-analog conversion yields the analog baseband signal of the pilot branch, represented as: ； in, This represents a continuous-time variable.

6. The method for generating ultra-wideband navigation signals based on linear frequency modulation spreading codes according to claim 5, characterized in that, Based on the data code, the pseudo-random spreading code of the data branch, and the linear frequency modulation spreading code of the data branch, the digital baseband signal of the data branch is generated, and then the analog baseband signal of the data branch is generated through digital-to-analog conversion, including: According to the data code Pseudo-random spreading codes for data branches Linear frequency modulation spreading code for data branches The digital baseband signal of the generated data branch is represented as: ； right Performing digital-to-analog conversion yields the analog baseband signal of the data branch, represented as: 。 7. The method for generating ultra-wideband navigation signals based on linear frequency modulation spreading codes according to claim 6, characterized in that, The radio frequency carrier for generating ultra-wideband navigation signals based on the radio frequency and the initial phase of the carrier is represented as: ； in, For radio frequency, Represents a continuous-time variable. The initial phase of the carrier. This is the symbol for a complex number.

8. The method for generating ultra-wideband navigation signals based on linear frequency modulation spreading codes according to claim 7, characterized in that, Based on the analog baseband signal of the pilot branch, the analog baseband signal of the data branch, and the radio frequency carrier, a complete ultra-wideband navigation signal is generated, represented as: ； in, The analog baseband signal for the data branch consists of a pseudo-random spreading code, a linear frequency modulation spreading code, and a data code containing navigation message data. It is the analog baseband signal of the pilot branch, composed of pseudo-random spreading code and linear frequency modulation spreading code, and does not contain navigation message data.

9. An ultra-wideband navigation signal generation device based on linear frequency modulation spreading code, characterized in that, The method for generating ultra-wideband navigation signals based on linear frequency modulation spreading codes, as described in any one of claims 1-8, includes: The linear frequency modulation spreading code phase calculation module is used to calculate and generate the phase of the linear frequency modulation spreading code under the drive of the generating clock. The phase quantization module is used to quantize the phase of the linear frequency modulation spreading code into a fixed angle using a phase quantization model that satisfies the cooperative optimization constraints of generation complexity and sidelobe suppression performance. The linear frequency modulation spreading code generation module is used to generate linear frequency modulation spreading codes for the data branch and the pilot branch based on the phase angle of the quantized linear frequency modulation spreading code. The pseudo-random spreading code phase calculation module is used to calculate the phase of the generated pseudo-random spreading code under the drive of the generation clock. A pseudo-random spreading code generation module is used to generate pseudo-random spreading codes for the data branch and the pilot branch based on the phase of the pseudo-random spreading code. The data code generation module is used to generate a data code containing navigation message data based on navigation message information and message encoding scheme; The first multiplier is used to generate the digital baseband signal of the pilot branch based on the pseudo-random spreading code and the linear frequency modulation spreading code of the pilot branch. The first digital-to-analog converter is used to convert the digital baseband signal of the pilot branch into an analog baseband signal of the pilot branch. The second multiplier is used to generate the digital baseband signal of the data branch based on the data code, the pseudo-random spreading code of the data branch, and the linear frequency modulation spreading code of the data branch. The second digital-to-analog converter is used to convert the digital baseband signal of the data branch into an analog baseband signal of the data branch. The carrier generation module is used to generate the radio frequency carrier of the ultra-wideband navigation signal based on the radio frequency and the initial phase of the carrier. The ultra-wideband navigation signal generation module is used to generate a complete ultra-wideband navigation signal based on the analog baseband signal of the pilot branch, the analog baseband signal of the data branch, and the radio frequency carrier.

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