CN104237901A

CN104237901A - Satellite navigation and communication integrated method and system

Info

Publication number: CN104237901A
Application number: CN201410514108.2A
Authority: CN
Inventors: 路冠平; 郜锦雷; 应忍冬; 刘佩林; 郁文贤
Original assignee: Shanghai Jiao Tong University
Current assignee: Shanghai Jiao Tong University
Priority date: 2014-09-29
Filing date: 2014-09-29
Publication date: 2014-12-24

Abstract

The invention discloses a satellite navigation and communication integrated method and system. The method includes the steps of S1, subjecting a navigation signal and a communication signal to multi-carrier modulation to obtain a modulated signal which is then sent out; S2, receiving the modulated signal and demodulating the modulated signal, and acquiring the communication signal and the navigation signal. The system comprises a signal processing and transmitting module and a signal receiving and processing module; the signal processing and transmitting module is used for subjecting the navigation signal and the communication signal to multi-carrier modulation to acquire the modulated signal which is then sent out; the signal receiving and processing module is used for receiving the modulated signal and demodulating the modulated signal to obtain the communication signal. The method and the system according to the technical scheme have the advantages that system transmission efficiency and spectral utilization rate can be increased, and anti-interference performance of the system can be enhanced.

Description

Satellite navigation communication integration method and system

技术领域technical field

本发明涉及卫星通信技术领域，尤其涉及一种卫星导航通信一体化方法及系统。The invention relates to the technical field of satellite communication, in particular to a method and system for integrating satellite navigation and communication.

背景技术Background technique

卫星导航定位技术如今的应用十分广泛，现有的全球卫星导航系统包括美国的GPS(Global Positioning System)、中国的北斗、俄罗斯GLONASS(GLObal Navigation SatelliteSystem),欧洲的Galileo系统。而现有的全球卫星导航系统如GPS只具有发送导航电文的能力，不具备数据通信的功能。现有导航系统中的卫星通信功能也一直局限于短数据通信，仅仅只能满足简单信息的传递。而且现有技术中的通信系统与导航系统分离，通信资源配置的固定使得通信性能一直无法提升，也无法解决通信信道不足和导航信道冗余等问题，成为了卫星通信能力提升的瓶颈。同时，现有的导航通信分开的设计思路，导致导航信号不容易隐蔽,极易被攻击。Satellite navigation and positioning technology is widely used today. The existing global satellite navigation systems include GPS (Global Positioning System) in the United States, Beidou in China, GLONASS (GLObal Navigation Satellite System) in Russia, and Galileo in Europe. However, existing global satellite navigation systems such as GPS only have the ability to send navigation messages, and do not have the function of data communication. The satellite communication function in the existing navigation system has also been limited to short data communication, which can only meet the transmission of simple information. Moreover, the communication system in the prior art is separated from the navigation system, and the fixed configuration of communication resources makes it impossible to improve the communication performance, and it is also unable to solve the problems of insufficient communication channels and redundant navigation channels, which has become a bottleneck for the improvement of satellite communication capabilities. At the same time, the existing design idea of separating navigation and communication makes the navigation signal not easy to hide and easily attacked.

如何将卫星的导航与通信功能结合起来实现资源的优化配置，并以较低的成本和硬件复杂度实现卫星与地面之间的高质量的通信和导航。成为现阶段亟需解决的问题。How to combine satellite navigation and communication functions to achieve optimal allocation of resources, and achieve high-quality communication and navigation between satellites and the ground with lower cost and hardware complexity. become an urgent problem to be solved at this stage.

发明内容Contents of the invention

本发明针对现有技术的不足，提出了一种能够提高系统的传输效率和频谱利用率的卫星导航通信一体化方法及系统。Aiming at the deficiencies of the prior art, the present invention proposes a satellite navigation and communication integration method and system capable of improving system transmission efficiency and frequency spectrum utilization.

一种卫星导航通信一体化方法，其特征在于，包括以下步骤：A satellite navigation and communication integration method is characterized in that it comprises the following steps:

S1：信号处理与发送模块将导航信号与通信信号进行多载波调制，获得调制信号后发送；S1: The signal processing and sending module performs multi-carrier modulation on the navigation signal and the communication signal, obtains the modulated signal and sends it;

S2：信号接收与处理模块接收所述调制信号并进行解调，获取所述通信信号和导航信号。S2: The signal receiving and processing module receives and demodulates the modulated signal, and acquires the communication signal and the navigation signal.

作为优化方案，步骤S1中所述多载波调制步骤具体为：As an optimization solution, the multi-carrier modulation step described in step S1 is specifically:

S101：对导航信号和通信信号进行扩频，信道编码，并按预设频谱分配方式进行频谱资源分配，获得初步处理信号；S101: Perform spectrum spreading and channel coding on navigation signals and communication signals, and perform spectrum resource allocation according to a preset spectrum allocation method to obtain preliminary processed signals;

S102：对所述初步调制信号进行滤波整形，获得滤波处理信号；S102: Filter and shape the preliminary modulation signal to obtain a filtered signal;

S103：对所述滤波处理信号进行IFFT变换，即将所述滤波处理信号调制在子载波上获得IFFT处理信号；S103: Perform IFFT transformation on the filtered processed signal, that is, modulate the filtered processed signal on a subcarrier to obtain an IFFT processed signal;

S104：对所述IFFT处理信号进行并串变换，获得所述调制信号；S104: Perform parallel-to-serial conversion on the IFFT processed signal to obtain the modulated signal;

步骤S2在进行解调之后还包括匹配滤波步骤。Step S2 also includes a matched filtering step after demodulation.

作为优化方案，所述调制信号调制在若干个子载波上，从而在一多载波信道中传输。As an optimization solution, the modulated signal is modulated on several sub-carriers, so as to be transmitted in a multi-carrier channel.

作为优化方案，所述调制信号在多载波信道中传输，所述多载波信道包含导航子信道和通信子信道；As an optimization solution, the modulated signal is transmitted in a multi-carrier channel, and the multi-carrier channel includes a navigation sub-channel and a communication sub-channel;

所述导航子信道包括偶数个导航信道，每个所述导航信道中对应一个子载波；所述通信子信道包含若干个通信信道，每个所述通信信道中对应一个子载波；The navigation sub-channel includes an even number of navigation channels, and each of the navigation channels corresponds to a sub-carrier; the communication sub-channel includes several communication channels, and each of the communication channels corresponds to a sub-carrier;

所述导航信号通过所述子载波在导航子信道中进行传输；The navigation signal is transmitted in a navigation subchannel through the subcarrier;

所述通信信号通过所述子载波在通信子信道中进行传输。The communication signal is transmitted in the communication sub-channel through the sub-carrier.

作为优化方案，所述预设频谱分配方式包括所述导航子信道和通信子信道对应不同所述子载波。As an optimization solution, the preset spectrum allocation method includes that the navigation sub-channel and the communication sub-channel correspond to different sub-carriers.

一种卫星导航通信一体化系统，其特征在于，包括：An integrated satellite navigation and communication system is characterized in that it comprises:

信号处理与发送模块：用于将导航信号与通信信号进行多载波调制，获得调制信号后发送；Signal processing and sending module: used for multi-carrier modulation of navigation signals and communication signals, and sending after obtaining modulated signals;

信号接收与处理模块：用于接收所述调制信号并进行解调，获取所述通信信号和导航信号。Signal receiving and processing module: used to receive and demodulate the modulated signal, and obtain the communication signal and navigation signal.

与现有技术相比，本发明具有以下有益效果：Compared with the prior art, the present invention has the following beneficial effects:

本发明提供一种导航、通信性能较为均衡的导航通信一体化系统，使其能够应用于导航系统备份、应急通信、导航信号辅助通信接收等场景。本发明技术方案提出的信号传输方案通过特别设计的并行多载波调制技术，将导航信道和通信信道统一在一起，在不改变时频域结构的前提下使导航子信道和通信子信道能够在一个系统内共存，从而提高了频谱利用率，降低了每路载波的信号速率，使得每路的成本和硬件复杂度都得到了降低。导航子信道与通信子信道的频谱灵活分配以满足系统的多种需求，提高了系统的抗干扰性能。该系统中的卫星平时用作数据通信，一旦其他导航卫星受到攻击不能正常使用时，这时卫星作为导航卫星的备用星，通过发射导航信号发挥导航作用。而且由于卫星信号中既包含通信信号又包含导航信号，因而可以较好地隐蔽导航信号，使其不容易受到干扰。本发明可扩展应用范围，且可应用于单载波或多载波传输系统。The present invention provides a navigation and communication integrated system with relatively balanced navigation and communication performance, so that it can be applied to scenarios such as navigation system backup, emergency communication, navigation signal auxiliary communication reception and the like. The signal transmission scheme proposed by the technical solution of the present invention unifies the navigation channel and the communication channel through the specially designed parallel multi-carrier modulation technology, and enables the navigation sub-channel and the communication sub-channel to be in one channel without changing the time-frequency domain structure. Coexistence in the system improves spectrum utilization, reduces the signal rate of each carrier, and reduces the cost and hardware complexity of each carrier. The frequency spectrum of the navigation sub-channel and the communication sub-channel is flexibly allocated to meet the various requirements of the system and improve the anti-jamming performance of the system. The satellites in this system are usually used for data communication. Once other navigation satellites are attacked and cannot be used normally, the satellites are used as backup satellites for navigation satellites and play a role in navigation by transmitting navigation signals. And because satellite signals include both communication signals and navigation signals, the navigation signals can be better concealed, making them less susceptible to interference. The invention can extend the scope of application, and can be applied to a single carrier or multi-carrier transmission system.

附图说明Description of drawings

图1为导航信号与通信信号的FMT调制框图；Fig. 1 is the FMT modulation block diagram of navigation signal and communication signal;

图2为导航信号与通信信号的FMT解调框图；Fig. 2 is the FMT demodulation block diagram of navigation signal and communication signal;

图3为导航数据处理框图；Fig. 3 is a block diagram of navigation data processing;

图4为导航子信道与通信子信道的一种频谱分配方式；Fig. 4 is a kind of spectrum allocation mode of navigation sub-channel and communication sub-channel;

图5为导航信号相关处理实现框图；Fig. 5 is the realization block diagram of navigation signal correlation processing;

具体实施方式Detailed ways

下面结合附图以具体实施例的方式对本发明进行详细说明。以下实施例将有助于本领域的技术人员进一步理解本发明，但不以任何形式限制本发明。应当指出的是，对本领域的普通技术人员来说，在不脱离本发明构思的前提下，还可以做出若干变形和改进。这些都属于本发明的保护范围。The present invention will be described in detail below in terms of specific embodiments in conjunction with the accompanying drawings. The following examples will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

本实施例所述信道表示信号传输所占用的频率带宽，其中导航子信道与传输导航信号的子载波所在频率段对应，通信子信道与传输通信信号的子载波所在频率段对应，如图4所示。The channel described in this embodiment represents the frequency bandwidth occupied by signal transmission, wherein the navigation sub-channel corresponds to the frequency segment where the sub-carrier that transmits the navigation signal is located, and the communication sub-channel corresponds to the frequency segment where the sub-carrier that transmits the communication signal is located, as shown in Figure 4 Show.

多载波调制技术就是通过在M个子信道上并行传输数据，使每个子信道内的符号持续时间扩展为单载波传输时的M倍，从而有效地降低由时延扩展所导致的符号间干扰(ISI，Inter-symbol Interference)，大大降低了误码率，同时也降低了数据处理的速度要求和硬件复杂度。Multi-carrier modulation technology is to transmit data in parallel on M sub-channels, so that the symbol duration in each sub-channel is extended to M times that of single-carrier transmission, thereby effectively reducing the inter-symbol interference (ISI) caused by delay spread. , Inter-symbol Interference), which greatly reduces the bit error rate, and also reduces the speed requirements and hardware complexity of data processing.

滤波多音调制(FMT，Filtered Multitone Modulation)系统的子信道频谱互不重叠，各子信道具有很高的频谱约束性，对系统频率偏差不敏感。FMT系统互不重叠的子信道频谱使得接收信号中信道间干扰(ICI，Inter channel Interference)可忽略不计，使系统获得良好的抗ICI性能，并且便于频谱的管理。在实现结构上，FMT可以用离散傅立叶反变换(IDFT，Inversed Discrete Fourier Transform)和傅立叶变换(DFT，Discrete Fourier Transform)高效实现。The sub-channel spectrum of the Filtered Multitone Modulation (FMT, Filtered Multitone Modulation) system does not overlap each other, and each sub-channel has a high spectrum constraint and is not sensitive to the system frequency deviation. The non-overlapping sub-channel spectrum of the FMT system makes the Inter-channel Interference (ICI) in the received signal negligible, which enables the system to obtain good anti-ICI performance and is convenient for spectrum management. In terms of implementation structure, FMT can be efficiently implemented with Inverse Discrete Fourier Transform (IDFT, Inversed Discrete Fourier Transform) and Fourier Transform (DFT, Discrete Fourier Transform).

本实施例的信号处理与发送模块对导航信号和通信信号统一采用FMT调制，FMT调制过程如图1所示。The signal processing and sending module of this embodiment uniformly adopts FMT modulation for navigation signals and communication signals, and the FMT modulation process is shown in FIG. 1 .

如图1所示，进行FMT调制之前还包括匹配滤波步骤，本实施例的匹配滤波模块为平方根升余弦(SRRC)滤波器。As shown in FIG. 1 , a matched filtering step is included before FMT modulation, and the matched filtering module in this embodiment is a square root raised cosine (SRRC) filter.

本发明中滤波器设计非常关键。一般来讲，传统上滤波器需要满足"完美重构"的限制，以保证传输中的ISI不会影响性能。本实施例采用截短的滤波器，在通过滤波器组技术将多个子载波通过频域结构相同的滤波器发送出去的同时，可以有效避免滤波器长度受到频域处理复杂度的限制，保证了信号传输中的ISI不会影响性能。进一步地，本实施例采用的是截短的根升余弦奈奎斯特滤波器。选取T₀为符号周期，则f₀＝1/2T₀为奈奎斯特频率，H(f)为频率响应。由SRRC的性质,如果收端需要恢复频域信号,则一路子载波的频谱需要包含滚降成型。取滚降系数为ρ,则有频域冲击响应为：Filter design is very critical in the present invention. In general, filters have traditionally been required to meet the "perfect reconstruction" constraint to ensure that ISI in transmission does not affect performance. This embodiment adopts a truncated filter, and while multiple subcarriers are sent out through filters with the same frequency domain structure through the filter bank technology, it can effectively avoid the limitation of the filter length by the frequency domain processing complexity, ensuring ISI in signal transmission does not affect performance. Further, this embodiment adopts a truncated root raised cosine Nyquist filter. T ₀ is selected as the symbol period, then f ₀ =1/2T ₀ is the Nyquist frequency, and H(f) is the frequency response. Due to the nature of SRRC, if the receiving end needs to restore the frequency domain signal, the spectrum of one subcarrier needs to include roll-off shaping. Taking the roll-off coefficient as ρ, the frequency-domain impulse response is:

$| | H h ((f f)) | | = = \{\begin{matrix} 11 if if | | f f | | \leq \leq ((11 - - ρ ρ)) / / 22 {T T}_{00} \\ \frac{11}{\sqrt{22}} \sqrt{11 - - sin sin \frac{π π}{ρ ρ} ((f f {T T}_{00} - - \frac{11}{22}))} \\ 00 otherwise otherwise \end{matrix} ((11 - - ρ ρ)) / / 22 {T T}_{00} \leq \leq | | f f | | \leq \leq ((11 + + ρ ρ)) / / 22 {T T}_{00}$

由SRRC滤波器性质得到f₁＝(1+ρ)f₀为频域主瓣宽度,则为了能量化其主瓣宽度，需要选取合适的采样率。According to the property of SRRC filter, f ₁ =(1+ρ)f ₀ is the width of the main lobe in the frequency domain. In order to quantify the width of the main lobe, it is necessary to select an appropriate sampling rate.

在一个系统中，通常采样频率f_s首先被确定。然后，由于f₁＝(1+ρ)f₀，则有f_s/f₀＝(1+ρ)f_s/f₁。通过适当的选取整数M₀＝f_s/f₀，M₁＝f_s/f₁，就可以得到整个系统的参数。其中，M₀为一个符号内的采样点个数，M₁为一个与滤波器频域相关的标记。In a system, usually the sampling frequency f _s is first determined. Then, since f ₁ =(1+ρ)f ₀ , f _s /f ₀ =(1+ρ)f _s /f ₁ . By properly selecting the integers M ₀ =f _s /f ₀ and M ₁ =f _s /f ₁ , the parameters of the entire system can be obtained. Among them, M ₀ is the number of sampling points in one symbol, and M ₁ is a label related to the frequency domain of the filter.

在本实施例中，导航信号采用SRRC+QPSK信号。因此，导航子信号可表示为：In this embodiment, the navigation signal adopts SRRC+QPSK signal. Therefore, the navigation sub-signal can be expressed as:

$x x ((i i)) = = \underset{k k}{Σ Σ} a a ((m m)) {c c}_{Σ Σ} ((i i)) {e e}^{j j 22 πk πk / / {M m}_{11}}$

其中， $c_{Σ} (i) = (Σ_{n = 0}^{2045} c (n, k) g_{SRRC} (i - n T_{c})) .$ in, $c_{Σ} (i) = (Σ_{no = 0}^{2045} c (no, k) g_{SRRC} (i - no T_{c})) .$

导航信号a(m)是调制信号，m为导航信号的符号宽度，c为CDMA扩频码，如图1中所示的扩频码为c₁(t)，T_c为CDMA扩频码码元宽度，其中扩频比为2046,即每个符号内有2046个码元，g表示SRRC滤波器。导航子信号表达式中的k有两个取值，即表示x(i)如图4所示占用频带两端的两个子载波。图1中a_R(t)为导航信号。The navigation signal a(m) is a modulated signal, m is the symbol width of the navigation signal, c is the CDMA spreading code, the spreading code shown in Figure 1 is c ₁ (t), T _c is the CDMA spreading code Element width, where the spreading ratio is 2046, that is, there are 2046 symbols in each symbol, and g represents the SRRC filter. The k in the expression of the navigation sub-signal has two values, which means that x(i) occupies two sub-carriers at both ends of the frequency band as shown in FIG. 4 . In Fig. 1, a _R (t) is the navigation signal.

本实施例将通信子信道与导航子信道进行FMT调制，图1中a_c(t)为通信信号。In this embodiment, FMT modulation is performed on the communication sub-channel and the navigation sub-channel, and a _c (t) in FIG. 1 is a communication signal.

在时域上，通信信号a_c(t)按照如图4所示的规则进行排布和传输。In the time domain, the communication signal a _c (t) is arranged and transmitted according to the rules shown in FIG. 4 .

在频域上，通信信号的FMT子载波还可以按规则分成若干个子频段，每个通信子频段可独立承载相同或不同的通信数据通道，通信子频段是能够使用的最小频域资源。In the frequency domain, the FMT subcarriers of communication signals can also be divided into several sub-frequency bands according to the rules. Each communication sub-frequency band can independently carry the same or different communication data channels. The communication sub-frequency band is the smallest frequency domain resource that can be used.

卫星导航通信一体化系统应用于数据通信时，通信信道FMT数据帧的子载波被分配给每个通信客户端。每个通信客户端按照预先分配的子载波进行信号帧生成，则每个子载波上传输的通信信号可以写成：When the satellite navigation and communication integrated system is applied to data communication, the subcarriers of the FMT data frame of the communication channel are allocated to each communication client. Each communication client performs signal frame generation according to pre-allocated subcarriers, then the communication signal transmitted on each subcarrier can be written as:

其中，g_SRRC(i-M₀m)为上文描述的SRRC滤波器，k为频域占用的子载波编号，i为时域采样点标号。Among them, g _SRRC (iM ₀ m) is the SRRC filter described above, k is the subcarrier number occupied by the frequency domain, and i is the label of the sampling point in the time domain.

以上就是卫星导航通信一体化系统的信号处理与发送模块的导航信号和通信信号的处理、调制过程。The above is the processing and modulation process of the navigation signal and communication signal of the signal processing and transmission module of the satellite navigation and communication integrated system.

在通信客户端接收到如图4所示格式的调制信号后，首先对调制信号进行如图2所示的FMT解调步骤。先进行串并变换，然后进行傅里叶变换(FFT)，最后进行匹配滤波，获得原始导航信号和通信信号。得到导航信号后，进一步对导航信号中导航数据进行捕获、跟踪、同步的操作步骤，进而解析导航电文。After the communication client receives the modulated signal in the format shown in FIG. 4 , it first performs the FMT demodulation steps shown in FIG. 2 on the modulated signal. Perform serial-to-parallel transformation first, then perform Fourier transform (FFT), and finally perform matched filtering to obtain the original navigation signal and communication signal. After the navigation signal is obtained, the navigation data in the navigation signal is further captured, tracked, and synchronized, and then the navigation message is analyzed.

如图3所示的匹配滤波主要是设计与FMT调制时所用的SRRC滤波器相匹配的滤波器。The matched filter shown in Figure 3 is mainly to design a filter that matches the SRRC filter used in FMT modulation.

其中捕获步骤主要包括码相关步骤和多普勒检测步骤，如图3。The acquisition step mainly includes a code correlation step and a Doppler detection step, as shown in FIG. 3 .

跟踪过程主要包括载波跟踪和C/A码跟踪。下面为本实施例所用的载波跟踪步骤。The tracking process mainly includes carrier tracking and C/A code tracking. The following are the carrier tracking steps used in this embodiment.

在导航信号相关时，输入两个对称的载波(I路和Q路)如图5，同相支路(I路)的本地复现信号可以表示为When the navigation signal is correlated, two symmetrical carriers (I and Q) are input as shown in Figure 5, and the local reproduction signal of the in-phase branch (I) can be expressed as

${x x}_{L L,, n no}^{I I} ((n no)) = = (({g g}_{n no}^{I I} ((t t)) + + {g g}_{- - n no}^{I I} ((t t)))) cos cos ((22 π π {\overset{^^}{f f}}_{c c} t t + + \overset{^^}{θ θ})) - - (({g g}_{n no}^{Q Q} ((t t)) + + {g g}_{- - n no}^{Q Q} ((t t)))) sin sin ((22 π π {\overset{^^}{f f}}_{c c} t t + + \overset{^^}{θ θ}))$

${g g}_{n no}^{I I} ((t t)) = = {A A}_{n no} c c ((t t - - Δτ Δτ)) . . cos cos [[22 π π {f f}_{n no} ((t t - - Δτ Δτ))]]$

${g g}_{n no}^{Q Q} ((t t)) = = {A A}_{n no} c c ((t t - - Δτ Δτ)) . . sin sin [[22 π π {f f}_{n no} ((t t - - Δτ Δτ))]]$

其中，A_n为幅度值，Δτ为延时，f_n为载波频率，为估计的中频频率。为估计的载波的相位。Among them, A _n is the amplitude value, Δτ is the delay time, f _n is the carrier frequency, is the estimated IF frequency. is the estimated carrier phase.

正交支路(Q路)的本地复现信号可以表示为The local reproduction signal of the quadrature branch (Q-way) can be expressed as

${x x}_{L L,, n no}^{Q Q} ((n no)) = = - - (({g g}_{n no}^{I I} ((t t)) + + {g g}_{- - n no}^{I I} ((t t)))) cos cos ((22 π π {\overset{^^}{f f}}_{c c} t t + + \overset{^^}{θ θ})) - - (({g g}_{n no}^{Q Q} ((t t)) - - {g g}_{- - n no}^{Q Q} ((t t)))) sin sin ((22 π π {\overset{^^}{f f}}_{c c} t t + + \overset{^^}{θ θ}))$

然后将X(t)分别与和进行相关可得Then compare X(t) with and get related

${s the s}_{n no}^{I I} [[k k]] \approx \approx {A A}_{n no}^{22} . . {d d}_{n no}^{k k} . . {R R}_{cc cc} ((Δτ Δτ)) . . cos cos ((22 π π {f f}_{n no} Δτ Δτ)) . . sin sin c c ((πΔf πΔf {T T}_{R R})) . . sin sin ((πΔf πΔf 22 k k {T T}_{R R} + + Δθ Δθ))$

${s the s}_{n no}^{Q Q} [[k k]] \approx \approx {A A}_{n no}^{22} . . {d d}_{n no}^{k k} . . {R R}_{cc cc} ((Δτ Δτ)) . . cos cos ((22 π π {f f}_{n no} Δτ Δτ)) . . sin sin c c ((πΔf πΔf {T T}_{R R})) . . cos cos ((πΔf πΔf 22 k k {T T}_{R R} + + Δθ Δθ))$

式中第三项为码相关峰，最后根据得到的相关结果可以获得锁相环和锁频环的输出，从而得到需要估计的精度。The third item in the formula is the code correlation peak. Finally, the output of the phase-locked loop and frequency-locked loop can be obtained according to the obtained correlation results, so as to obtain the accuracy that needs to be estimated.

在完成跟踪过程、进一步实现同步后，我们就能解析导航电文，获取卫星到地面端的伪距信息。在得到多个(四个及以上)卫星到地面端的伪距信息后，我们就可以求解出地面端的位置坐标，完成定位。After completing the tracking process and further achieving synchronization, we can analyze the navigation message and obtain the pseudo-range information from the satellite to the ground terminal. After obtaining the pseudo-range information from multiple (four or more) satellites to the ground terminal, we can solve the position coordinates of the ground terminal and complete the positioning.

以上所述仅是本发明的优选实施方式，应当指出，对于本技术领域的普通技术人员来说，在不脱离本发明技术原理的前提下，还可以做出若干改进和润饰，这些改进和润饰也应视为本发明的保护范围。The above is only a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the technical principle of the present invention, some improvements and modifications can also be made. These improvements and modifications It should also be regarded as the protection scope of the present invention.

Claims

1. A satellite navigation communication integration method is characterized by comprising the following steps:

s1: the signal processing and transmitting module carries out multi-carrier modulation on the navigation signal and the communication signal to obtain a modulation signal and then transmits the modulation signal;

s2: and the signal receiving and processing module receives and demodulates the modulation signal to acquire the communication signal and the navigation signal.

2. The method of claim 1,

the multi-carrier modulation step in step S1 specifically includes:

s101: carrying out spread spectrum and channel coding on the navigation signal and the communication signal, and carrying out spectrum resource allocation according to a preset spectrum allocation mode to obtain a primary processing signal;

s102: filtering and shaping the preliminary modulation signal to obtain a filtering processing signal;

s103: performing IFFT transformation on the filtered signal, i.e. modulating the filtered signal on a subcarrier to obtain an IFFT-processed signal;

s104: performing parallel-to-serial conversion on the IFFT processing signal to obtain the modulation signal;

step S2 also includes a matched filtering step after demodulation.

3. The method of claim 1,

the modulated signal is modulated onto a number of subcarriers for transmission in a multicarrier channel.

4. The method of claim 3, wherein the modulated signal is transmitted in a multicarrier channel, the multicarrier channel comprising a navigation subchannel and a communications subchannel;

the navigation sub-channels comprise an even number of navigation channels, and each navigation channel corresponds to one sub-carrier; the communication sub-channels comprise a plurality of communication channels, and each communication channel corresponds to one sub-carrier;

the navigation signal is transmitted in a navigation sub-channel through the sub-carrier;

the communication signal is transmitted in a communication sub-channel over the sub-carriers.

5. The method of claim 4,

the preset spectrum allocation mode comprises that the navigation sub-channel and the communication sub-channel correspond to different sub-carriers.

6. A satellite navigation communication integration system, comprising:

the signal processing and transmitting module: the system is used for carrying out multi-carrier modulation on the navigation signal and the communication signal to obtain a modulation signal and then sending the modulation signal; the signal receiving and processing module: and the system is used for receiving and demodulating the modulation signal to acquire the communication signal and the navigation signal.

7. The integrated satellite navigation communication system according to claim 6, wherein the modulated signal is transmitted in a multi-carrier channel, the multi-carrier channel comprising a navigation sub-channel and a communication sub-channel;