CN115801517A - Carrier processing method and related equipment based on air-ground joint jamming system - Google Patents

Abstract

The invention relates to the technical field of communication interference, and discloses a carrier processing method based on an air-ground combined interference system and related equipment, which are used for realizing carrier modulation and demodulation, synchronization, carrier frequency deviation estimation, carrier channel equalization and peak-to-average ratio reduction processing, so that an ad hoc network has the characteristics of strong multipath fading resistance, strong interference resistance, high frequency utilization rate and suitability for high-speed data transmission. The method comprises the following steps: in the transmitter part, according to the transmission data required by different sending rates, the carrier wave of the transmission data is correspondingly modulated by using BPSK, QPSK, 16QAM or 64QAM modulation modes, and all the modulated mappings are normalized; in the receiver part, a complex signal containing in-phase and orthogonal components is received, and when the complex signal falls in a corresponding rectangular area according to a modulation mapping relation used in modulation, a corresponding code element is judged to be recovered original transmission data.

Description

Carrier processing method and related equipment based on air-ground joint jamming system

technical field

The invention relates to the technical field of communication interference, in particular to a carrier processing method and related equipment based on an air-ground joint interference system.

Background technique

In order to meet the requirements of the air-ground joint jamming system, the air-ground joint network is interconnected in the form of wireless ad hoc network. The wireless ad hoc network does not rely on the existing fixed communication network infrastructure. The field has requirements for rapid deployment of communication networks, flexible networking, strong invulnerability, good mobility, and not limited by time and space.

Considering the complex electromagnetic environment application scenarios of the air-ground joint jamming system, it is easily affected by factors such as the electromagnetic environment, natural weather, and communication distance, and faces certain risks in terms of safety and reliability. The multipath and time variation caused by the surrounding environment are two important factors affecting the communication system of the ad hoc network. Multipath will cause the wireless signal to suffer from frequency selective fading, and the time variation will cause the channel to change with time. Fading, the present invention realizes data transmission by using OFDM (Orthogonal Frequency Division Multiplexing, orthogonal frequency division multiplexing technology) in the above-mentioned air-ground joint interference system, and realizes data modulation and demodulation with a digital signal processor, to reduce wireless channel Multipath related issues. Since the ability of the communication path to transmit data in the ad hoc network system will change with time, OFDM can dynamically adapt to it, and can almost completely overcome the intersymbol interference caused by multipath, and is especially suitable for multiple space-ground joint interference systems. User distributed ad hoc network network.

The present invention provides a carrier processing method based on an air-ground joint interference system, which is used to realize carrier modulation and demodulation, carrier synchronization, carrier frequency deviation estimation, carrier channel equalization and peak-to-average ratio reduction processing, so that the ad hoc network has anti- Strong multipath fading ability, strong anti-interference ability, high frequency utilization rate, suitable for high-speed data transmission.

Contents of the invention

The present invention provides a carrier processing method and related equipment based on an air-ground joint interference system, which are used to realize carrier modulation and demodulation, carrier synchronization, carrier frequency deviation estimation, carrier channel equalization and peak-to-average ratio reduction processing, so that ad hoc The network has the characteristics of strong anti-multipath fading ability, strong anti-interference ability, high frequency utilization rate, and suitable for high-speed data transmission.

In order to achieve the above object, the first aspect of the present invention provides a carrier processing method based on the air-ground joint interference system, including:

In the transmitter part, according to the transmission data required by different transmission rates, correspondingly use BPSK, QPSK, 16QAM or 64QAM modulation to modulate the carrier of the transmission data, and normalize the mapping of all modulations;

In the receiver part, a complex signal containing in-phase and quadrature components is received, and according to the modulation mapping relationship used during modulation, when the complex signal falls in the corresponding rectangular area, the corresponding symbol is determined to be the restored original transfer data.

Optionally, in another embodiment of the carrier processing method based on the space-ground joint interference system, the method further includes:

In the transmitter part, a pilot signal is inserted into the frequency domain of the modulated carrier spectrum as a carrier synchronization signal, and the transmission data is converted from frequency to time domain signal by fast Fourier transform;

In the receiver part, the piloted carrier synchronization signal is received, and the time domain signal is transformed into a frequency domain signal by fast Fourier transform, and the pilot frequency is extracted according to the frequency domain signal, and the carrier frequency is estimated through the pilot frequency offset, and compensate the received signal in the time domain according to the carrier frequency offset.

Optionally, in another embodiment of the carrier processing method based on the space-ground joint interference system, the estimating the carrier frequency deviation through the pilot includes:

Use Acquisition mode for wide range carrier frequency offset estimation including integer carrier frequency offset and track mode for fine carrier frequency offset estimation.

Optionally, in another embodiment of the carrier processing method based on the space-ground joint interference system, the method further includes:

In the transmitter part, pre-embed specific training symbols in the transmission data;

In the receiver part, in order to estimate the frequency response of the channel, use the received training symbols to perform channel estimation and equalization on each data symbol in the carrier.

Optionally, in another embodiment of the carrier processing method based on the space-ground joint interference system, the method further includes:

In the receiver part, by periodically sensing the frequency points within a certain frequency band, it is known whether the current spectrum is being used by equipment, and the undisturbed frequency points are recorded;

According to the undisturbed frequency point, it is detected whether the preset ad hoc network link interruption condition is met, and if so, the link is interrupted or the frequency is changed uniformly throughout the network, wherein the unified frequency change of the entire network refers to the preset The anti-jamming remote control link sends an instruction to change the frequency to the ad hoc communication network of the entire air-ground joint jamming system.

Optionally, in another embodiment of the carrier processing method based on the space-ground joint interference system, the method further includes:

In the transmitter part, through the peak-to-average power ratio reduction strategy based on clipping and filtering, the peak value of the transmitted signal in the time domain through the fast Fourier transform is reduced, and the maximum amplitude of the transmitted signal is limited to a preset specified magnitude.

Optionally, in another embodiment of the carrier processing method based on the space-ground joint interference system, the peak-to-average power ratio reduction strategy based on clipping and filtering is to use clipping near the peak value of the transmitted signal in the time domain or nonlinear saturation to reduce the peak-to-average power ratio, including:

After the transmission data changes from the frequency to the time domain, it is processed by the first-level limiting, first phase compensation and BPF filtering modules, and continues to be processed by the second-level limiting, second phase compensation and LPF filtering modules, so as to obtain The time domain signal is output to the radio frequency end.

The second aspect of the present invention provides a carrier processing device based on an air-ground joint interference system, the device comprising:

The transmitting part module is used to modulate the carrier of the transmission data according to the transmission data required by different transmission rates, correspondingly using BPSK, QPSK, 16QAM or 64QAM modulation, and normalize the mapping of all modulations;

The receiving part module is used to receive a complex signal containing in-phase and quadrature components. According to the modulation mapping relationship used during modulation, when the complex signal falls in the corresponding rectangular area, the corresponding symbol is determined to be the recovered one. Raw transmission data.

Optionally, in another embodiment of the carrier processing device based on the air-ground joint interference system, the device further includes:

The pilot module is used to insert a pilot signal in the frequency domain of the modulated carrier spectrum, as a carrier synchronization signal, and transform the transmission data from frequency to time domain signal through fast Fourier transform;

The compensation module is used to receive the piloted carrier synchronization signal, and transform the time domain signal into a frequency domain signal through fast Fourier transform, extract the pilot frequency according to the frequency domain signal, and estimate the carrier frequency through the pilot frequency offset, and compensate the received signal in the time domain according to the carrier frequency offset.

Optionally, in another embodiment of the carrier processing device based on the air-ground joint interference system, the compensation module specifically includes:

Carrier frequency offset estimation unit for wide range carrier frequency offset estimation including integer carrier frequency offset using acquisition mode and fine carrier frequency offset estimation using tracking mode.

Optionally, in another embodiment of the carrier processing device based on the air-ground joint interference system, the device further includes:

A training symbol embedding module, used to embed specific training symbols in the transmission data in advance;

The channel estimation and equalization module is used for estimating the frequency response of the channel, and performing channel estimation and equalization on each data symbol in the carrier by using the received training symbols.

Optionally, in another embodiment of the carrier processing device based on the air-ground joint interference system, the device further includes:

The frequency point sensing module is used to periodically sense the frequency points within a certain frequency band to know whether the current spectrum is being used by equipment, and record the undisturbed frequency points;

The detection and processing module is used to detect whether the preset ad hoc network link interruption condition is met according to the undisturbed frequency point, and if so, interrupt the link or uniformly change the frequency of the entire network, wherein the entire network Unified frequency change means that the preset anti-jamming remote control link sends an instruction to change frequency to the ad hoc communication network of the entire air-ground joint jamming system.

Optionally, in another embodiment of the carrier processing device based on the air-ground joint interference system, the device further includes:

The peak-to-average ratio reduction module is used to reduce the peak value of the transmitted signal in the time domain through the fast Fourier transform through the peak-to-average power ratio reduction strategy based on clipping and filtering, and limit the maximum amplitude of the transmitted signal to a predetermined value. Set the specified range.

Optionally, in another embodiment of the carrier processing device based on the space-ground joint interference system, the peak-to-average power ratio reduction strategy based on clipping and filtering is to use clipping near the peak value of the transmitted signal in the time domain Or nonlinear saturation to reduce the peak-to-average power ratio, the peak-to-average ratio reduction module specifically includes:

The peak-to-average ratio reduction processing unit is used to transmit data from the frequency domain to the time domain, after the processing of the first-level limiting, the first phase compensation and the BPF filter module, and continue to go through the second-level limiting and second phase compensation and the processing of the LPF filter module, so that the obtained time domain signal is output to the radio frequency end.

The third aspect of the present invention also provides a carrier processing device based on a joint air-ground interference system, wherein the carrier processing device based on a joint air-ground interference system includes a memory and at least one processor, and instructions are stored in the memory, and the The memory and the at least one processor are interconnected through a line; the at least one processor calls the instruction in the memory, so that the carrier processing device based on the air-ground joint interference system executes any one of the above-mentioned based on Carrier processing method for air-ground joint jamming system.

The fourth aspect of the present invention also provides a computer-readable storage medium, on which a computer program is stored, wherein, when the computer program is executed by a processor, the carrier processing method based on the air-ground joint interference system as described in any one of the above is implemented .

In the technical solution provided by the present invention, by using the BPSK, QPSK, 16QAM or 64QAM modulation mode to modulate the carrier of the transmission data according to the transmission data required by different transmission rates in the transmitter part, and map all modulated Perform normalization; in the receiver part, receive a complex signal containing in-phase and quadrature components, and according to the modulation mapping relationship used during modulation, when the complex signal falls in the corresponding rectangular area, the corresponding symbol is determined In order to restore the original transmission data, the present invention realizes carrier modulation and demodulation, carrier synchronization, carrier frequency deviation estimation, carrier channel equalization and peak-to-average ratio reduction processing by providing a carrier processing scheme based on the air-ground joint interference system, so that the The networking network has the characteristics of strong anti-multipath fading ability, strong anti-interference ability, high frequency utilization rate, and suitable for high-speed data transmission.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained according to these drawings without creative work.

FIG. 1 is a schematic diagram of an embodiment process of a carrier processing method based on a space-ground joint interference system in an embodiment of the present invention;

FIG. 2 is a schematic diagram of an embodiment of a carrier processing device based on a space-ground joint interference system in an embodiment of the present invention;

Fig. 3 is a schematic diagram of an embodiment of a carrier processing device based on a joint space-ground interference system in an embodiment of the present invention.

Detailed ways

The embodiment of the present invention provides a carrier processing method and related equipment based on the air-ground joint interference system, which are used to realize carrier modulation and demodulation, carrier synchronization, carrier frequency deviation estimation, carrier channel equalization and peak-to-average ratio reduction processing, so that The ad hoc network has the characteristics of strong anti-multipath fading ability, strong anti-interference ability, high frequency utilization rate, and suitable for high-speed data transmission.

In order to enable those skilled in the art to better understand the solutions of the present invention, the embodiments of the present invention will be described below with reference to the drawings in the embodiments of the present invention.

The terms "first", "second", "third", "fourth", etc. (if any) in the description and claims of the present invention and the above drawings are used to distinguish similar objects, and not necessarily Used to describe a specific sequence or sequence. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments described herein can be practiced in sequences other than those illustrated or described herein. Furthermore, the term "comprising" or "having" and any variations thereof, are intended to cover a non-exclusive inclusion, for example, a process, method, system, product or device comprising a sequence of steps or elements is not necessarily limited to those explicitly listed instead, may include other steps or elements not explicitly listed or inherent to the process, method, product or apparatus.

In order to prevent the complex electromagnetic environment application scenarios of the air-ground joint interference system, it is easily affected by factors such as the electromagnetic environment, natural weather, and communication distance. The resulting multipath and time variation are two important influencing factors. Multipath will cause wireless signals to suffer Frequency-selective fading, time-varying causes the channel to change accordingly over time. Since the ability of the communication path to transmit data in the ad hoc network system will change with time, OFDM (Orthogonal Frequency Division Multiplexing, that is, Orthogonal Frequency Division Multiplexing technology) can dynamically adapt to it and can almost completely overcome the problems caused by multipath. Intersymbol interference, especially suitable for multi-user distributed ad hoc network of air-ground joint interference system. The present invention implements carrier modulation and demodulation, carrier synchronization, carrier frequency deviation estimation, carrier channel equalization and peak-to-average ratio reduction processing based on OFDM, so that the ad hoc network has strong anti-multipath fading ability, strong anti-interference ability, frequency High utilization rate, suitable for high-speed data transmission.

Referring to FIG. 1, an embodiment of a carrier processing method based on a space-ground joint interference system in an embodiment of the present invention includes:

Step 101 In the transmitter part, according to the transmission data required by different transmission rates, correspondingly use BPSK, QPSK, 16QAM or 64QAM modulation to modulate the carrier of the transmission data, and normalize the mapping of all modulations;

Step 102. In the receiver part, receive a complex signal containing in-phase and quadrature components. According to the modulation mapping relationship used during modulation, when the complex signal falls in the corresponding rectangular area, the corresponding symbol is judged to be recovery out of the original transmission data.

The transmitters of each network resource in the space-ground joint interference system modulate the information bit sequence into PSK/QAM symbols, and then perform inverse fast Fourier transform on the corresponding symbols to transform them into time-domain signals, and finally pass the corresponding wireless channel They shoot out. During specific implementation, in the transmitter part, according to the transmission data required by different transmission rates, correspondingly use BPSK, QPSK, 16QAM or 64QAM modulation to modulate the carrier of the transmission data, and normalize the mapping of all modulations, That is, according to different rate requirements, OFDM subcarriers need to be modulated by BPSK, QPSK, 16QAM or 64QAM modulation. After the data is encoded and interleaved, the serial data stream is divided into groups of 1, 2, 4 or 6 bits, and mapped into complex numbers according to certain rules to form BPSK, QPSK, 16QAM or 64QAM modulation.

1/42。譬如，16QAM调制方式，其星座图上有16个采样点，每个采样点表示一种矢量状态，16QAM有16态，每4位二进制规定了16态中的一态，16QAM的每个符号时间传送4比特映射。经过预设的16QAM编码表映射后得到I/Q数据再乘以

进行归一化，即得到调制后的I/Q值。I/Q数据分别进行模数变换，得到两路模拟电平信号，用于和cosωt，-sinωt相乘，从而实现调制。During the transmission process, the modulation method may change, for example, the BPSK modulation adopted by the command frame in the transmitted data, and another modulation adopted by the data frame. In order for all maps to have the same average power, the maps need to be normalized. The mapped complex number is multiplied by a normalization quantity K _mod to obtain the output data. The value of normalization quantity K _mod is different according to different modulation modes, and the BPSK, QPSK, 16QAM or 64QAM modulation mode of the present invention, the value of corresponding normalization quantity K _mod is respectively 1,

1/42. For example, in the 16QAM modulation mode, there are 16 sampling points on the constellation diagram, and each sampling point represents a vector state. 16QAM has 16 states, and each 4-bit binary specifies one of the 16 states. Each symbol time of 16QAM A 4-bit map is transmitted. After the preset 16QAM coding table is mapped, the I/Q data is multiplied by

Perform normalization to obtain the modulated I/Q value. The I/Q data are respectively subjected to analog-to-digital conversion to obtain two analog level signals, which are used to multiply cosωt and -sinωt to realize modulation.

Correspondingly, in the receiver part, in order to recover the transmitted data, demodulation is required. The command frame in the transmission data adopts the most reliable BPSK modulation to ensure the accuracy of the information, and the data frame in the transmission data has four different modulation methods according to different rate requirements. For example, take 16QAM as an example. Since 16QAM quadrature amplitude modulation changes the amplitude and phase of the carrier at the same time, it is a combination of ASK and PSK. Its mathematical form is: S(t)=Isin(w _c t)-Qcos(w _c t ); Among them, I, Q are in-phase component and quadrature component respectively. In the baseband signal processing process, what is sent to the demodulation module is generally a complex signal containing two components of in-phase and quadrature. The demodulation uses the received complex signal to restore the original digital information according to the modulation mapping relationship used during modulation. During the demodulation process, when the complex signal falls in the corresponding rectangular area, the corresponding symbol is judged as Recovered original transmission data

Optionally, in another embodiment of the carrier processing method based on the space-ground joint interference system, the method further includes:

In the transmitter part, a pilot signal is inserted into the frequency domain of the modulated carrier spectrum as a carrier synchronization signal, and the transmission data is converted from frequency to time domain signal by fast Fourier transform;

In the receiver part, the piloted carrier synchronization signal is received, and the time domain signal is transformed into a frequency domain signal by fast Fourier transform, and the pilot frequency is extracted according to the frequency domain signal, and the carrier frequency is estimated through the pilot frequency offset, and compensate the received signal in the time domain according to the carrier frequency offset.

其中，c为光速，定义归一化的载波频率偏差(简称CFO)为整数载波频率偏差与子载波间隔的比值：

令ε_i和ε_f分别表示ε的整数与小数部分，即ε＝ε_i+ε_f，载波频率的不同，对于时域信号x[n]，ε大小的载波频率偏差会引起2πnε的大小偏差，且相位与ε和n成正比，这相当于在频率信号X[k]上产生了一个-ε的频差。In the specific implementation, due to the characteristics of OFDM, the transmitter part transmits signals on multiple overlapping sub-channels. In order to receive correctly, the orthogonality between the sub-carriers must be strictly guaranteed. However, due to the Doppler frequency shift and the transceiver crystal oscillator The subcarriers are not exactly the same, and there is often a certain carrier frequency deviation, which will destroy the orthogonality between subcarriers, and the influence of this frequency difference on the phase is also cumulative. Therefore, in order to ensure OFDM performance, carrier frequency synchronization must be performed. The baseband signal is upconverted to the passband due to carrier modulation, and then the signal is downconverted to baseband at the receiver by using a local carrier with the same frequency. Generally speaking, there are two types of distortion related to the carrier signal with a certain carrier frequency deviation. One is the phase noise caused by the instability of the transmitter and receiver carrier signal generators, which can be modeled as a zero-mean Wiener stochastic process. The other is caused by the Doppler frequency shift f _d . Let f _c and f _c ' represent the carrier frequencies of the transmitter and receiver respectively; f _offset represents the difference between them, that is, f _offset =f _c -f _c '. The Doppler frequency shift f _d is jointly determined by the carrier frequency f _c and the speed v of the mobile terminal

Wherein, c is the speed of light, and the normalized carrier frequency deviation (referred to as CFO) is defined as the ratio of the integer carrier frequency deviation to the subcarrier spacing:

Let ε _i and ε _f represent the integer and fractional part of ε respectively, that is, ε=ε _i +ε _f , the carrier frequency is different, for the time domain signal x[n], the carrier frequency deviation of ε will cause the size deviation of 2πnε , and the phase is proportional to ε and n, which is equivalent to generating a -ε frequency difference on the frequency signal X[k].

For the above carrier frequency deviation situation, the present invention adopts the insertion pilot frequency in the frequency domain when designing, so that the receiver part can be recovered as a carrier synchronization signal, the sine wave corresponding to this line spectrum is called a pilot signal, and in each OFDM symbol Transmit in mid-range so that carrier frequency deviation can be tracked.

和

用于提取导频。最后，由频域导频估计出载波频率偏差，通过估计出的载波频率偏差在时域对接收信号进行补偿。First, two OFDM symbols y _l [n] and y _l+D [n] are combined after synchronization, and then, the time domain signal is transformed into a frequency domain signal by fast Fourier transform

and

Used to extract the pilot. Finally, the carrier frequency deviation is estimated from the frequency domain pilot, and the received signal is compensated in the time domain through the estimated carrier frequency deviation.

Optionally, in another embodiment of the carrier processing method based on the space-ground joint interference system, the estimating the carrier frequency deviation through the pilot includes:

Use Acquisition mode for wide range carrier frequency offset estimation including integer carrier frequency offset and track mode for fine carrier frequency offset estimation.

During specific implementation, the present invention adopts two different carrier frequency deviation estimation modes: acquisition mode and tracking mode. In acquisition mode, estimate a wide range of carrier frequency offsets including integer carrier frequency offsets. In tracking mode, only fine carrier frequency offset estimation is done. where the integer carrier frequency offset is estimated as:

其中，L、p[j]和X_l[p[j]]分别表示导频数、第j个导频的位置和第l个符号周期中位于p[j]处的导频。

Among them, L, p[j] and X _l [p[j]] represent the number of pilots, the position of the jth pilot and the pilot located at p[j] in the lth symbol period, respectively.

Meanwhile, the fine carrier frequency offset is estimated as:

That is, in the acquisition mode, _εacq and _εf are estimated, and then the carrier frequency deviation is compensated by their sum, and in the tracking mode, only _εf is estimated, and then the carrier frequency deviation is compensated by it.

Optionally, in another embodiment of the carrier processing method based on the space-ground joint interference system, the method further includes:

In the transmitter part, pre-embed specific training symbols in the transmission data;

In the receiver part, in order to estimate the frequency response of the channel, use the received training symbols to perform channel estimation and equalization on each data symbol in the carrier.

The signal received by the receiver part is usually distorted due to the influence of channel characteristics. In order to recover the bit information, the channel must be estimated and compensated at the receiver. As long as inter-carrier interference (ICI) does not occur, that is, the orthogonality between sub-carriers can be maintained, each sub-carrier can be regarded as an independent channel. This orthogonality allows each subcarrier component of the received signal to be expressed as the product of the channel frequency response of the transmitted signal and the subcarrier. Therefore, the transmitted signal can be recovered only by estimating the channel response of each subcarrier.

The impulse response of a time-varying channel is usually expressed as a discrete FIR filter:

可以认为信道在一个数据分组中保持不变，则与时间相关的项可以除掉，即

则信道的离散时间频率响应为：H_k＝DFT{h_n}。

It can be considered that the channel remains unchanged in a data packet, and the time-related items can be removed, namely

Then the discrete time frequency response of the channel is: H _k =DFT{h _n }.

According to different processing domains, channel estimation is divided into time domain and frequency domain. The former is performed before the discrete Fourier transform at the receiving end to estimate the channel impulse response; while the latter is performed after the discrete Fourier transform to estimate the channel frequency response. The two can also be combined to jointly perform channel estimation in the time domain and frequency domain, so as to fully tap the respective advantages of signal time domain processing and frequency domain processing.

The present invention adopts a simple and efficient method to estimate the frequency response of the channel, that is, performs channel estimation and equalization on each data symbol. That is, in the transmitter part, specific training symbols are embedded in the transmission data in advance; in the receiver part, in order to estimate the frequency response of the channel, channel estimation and equalization are performed on each data symbol in the carrier by using the received training symbols. During specific implementation, the OFDM symbol format received by the receiving end includes several specific training symbols and several data symbols. During the channel equalization process, the received training symbols are used to perform channel equalization on the channel of the data symbols. The present invention is for channel equalization Part of the processing method is to periodically insert training sequences in the process of transmitting data symbols, and then perform channel estimation according to symbol rules, that is, to estimate the channels of the middle four data symbols according to adjacent training symbols.

Optionally, in another embodiment of the carrier processing method based on the space-ground joint interference system, the method further includes:

In the receiver part, by periodically sensing the frequency points within a certain frequency band, it is known whether the current spectrum is being used by equipment, and the undisturbed frequency points are recorded;

According to the undisturbed frequency point, it is detected whether the preset ad hoc network link interruption condition is met, and if so, the link is interrupted or the frequency is changed uniformly throughout the network, wherein the unified frequency change of the entire network refers to the preset The anti-jamming remote control link sends an instruction to change the frequency to the ad hoc communication network of the entire air-ground joint jamming system.

Due to the interference of the surrounding environment of the air-ground joint interference system, in order to improve the anti-interference ability in the ad hoc network, the present invention adopts spectrum sensing technology, that is, periodically senses the frequency points within a certain frequency band range, and records the undisturbed frequency points. When it is found that the current ad hoc network link interruption meets certain conditions, it is considered that the link has suffered interference, and the link can be automatically interrupted, or a frequency point selected from the undisturbed frequency points is recommended to the operator, and the operator decides whether to The frequency of the entire network is changed uniformly. When the operator confirms that the frequency of the entire network is changed uniformly, the operator sends an instruction to change the frequency to the ad hoc communication network of the entire air-ground joint interference system through the preset anti-jamming remote control link. The receiver part of the present invention receives the baseband data after radio frequency down-conversion, processes it through AGC, and then calculates the power of the link, and then adds the power adjusted by AGC to obtain the entire link power, and the obtained power and spectrum are useless By comparing the power of the current spectrum, it can be found whether the current spectrum is being used by devices, that is, the spectrum sensing function is realized.

Optionally, in another embodiment of the carrier processing method based on the space-ground joint interference system, the method further includes:

In the transmitter part, through the peak-to-average power ratio reduction strategy based on clipping and filtering, the peak value of the transmitted signal in the time domain through the fast Fourier transform is reduced, and the maximum amplitude of the transmitted signal is limited to a preset specified magnitude.

Wherein, the peak-to-average power ratio reduction strategy based on clipping and filtering is to reduce the peak-to-average power ratio by clipping or nonlinear saturation near the peak value of the transmitted signal in the time domain, specifically including: the transmission data changes from the frequency After arriving in the time domain, it is processed by the first-level limiting, first phase compensation and BPF filtering modules, and continues to be processed by the second-level limiting, second phase compensation and LPF filtering modules, so that the obtained time-domain signal output to the RF side.

During specific implementation, all sub-carriers are added after the inverse fast Fourier transform operation, so the transmitted signal in the time domain will have a very high peak value. Therefore, compared with the single-carrier system, the OFDM multi-carrier system has a high peak-to-average power ratio (Peak to Average Power Ratio, PAPR). The high peak-to-average power ratio PAPR will reduce the efficiency of the transmitter power amplifier, and also reduce the signal quantization noise ratio (SQNR) of the ADC and DAC devices, so the function of reducing the peak-to-average ratio is considered in the design of the present invention.

PAPR reduction techniques can be divided into the following categories: limiting technology, coding technology, scrambling technology, adaptive pre-distortion technology and discrete Fourier transform spread spectrum technology.

And what adopt in the present invention is exactly wherein limit technology, and this technology adopts limit or non-linear saturation to reduce PAPR exactly near the peak value, and this technology realizes relatively simple, but it may cause in-band and out-of-band interference , and also destroys the orthogonality between subcarriers.

However, when the solution is implemented, clipping and filtering techniques, that is, filtering after clipping, can greatly reduce in-band and out-of-band interference when the orthogonality is satisfied. When the present invention is specifically implemented, the maximum amplitude of the transmitted signal is limited to a pre-specified level, and the PAPR reduction scheme based on limiting and filtering is realized. Specifically, after the transmission data changes from the frequency to the time domain, it is processed by the first-level limiting, first phase compensation and BPF filtering modules, and continues to be processed by the second-level limiting, second phase compensation and LPF filtering modules , so that the obtained time-domain signal is output to the radio frequency terminal. That is, after the data changes from the frequency to the time domain, after the first-level limiting processing, the output value caused by this operation will destroy the subcarrier orthogonality to a certain extent, and it will also cause in-band and out-of-band interference, so the following The phase compensation and BPF filter modules are added, and the problem caused by clipping can be solved well by using two modules. The implementation of the present invention applies two basically the same limiting and filtering operations, and the difference lies in the last stage of filtering device, in order to better output it to the radio frequency end.

To sum up, in the embodiment of the present invention, by using BPSK, QPSK, 16QAM or 64QAM modulation methods to modulate the carrier of the transmission data according to the transmission data required by different transmission rates in the transmitter part, and all modulation The mapping is normalized; in the receiver part, the complex signal containing two components of in-phase and quadrature is received, and according to the modulation mapping relationship used during modulation, when the complex signal falls in the corresponding rectangular area, the corresponding The symbol is the recovered original transmission data. The present invention realizes carrier modulation and demodulation, carrier synchronization, carrier frequency deviation estimation, carrier channel equalization and peak-to-average ratio reduction processing by providing a carrier processing scheme based on the air-ground joint interference system, thereby The ad hoc network has the characteristics of strong anti-multipath fading ability, strong anti-interference ability, high frequency utilization rate, and suitable for high-speed data transmission.

The carrier processing method based on the space-ground joint interference system in the embodiment of the present invention is described above. The following describes the carrier processing device based on the space-ground joint interference system in the embodiment of the present invention. Please refer to FIG. 2. In the embodiment of the present invention, based on the space-ground joint interference system An embodiment of the carrier processing device of the interfering system comprises:

The transmitting part module 11 is used to modulate the carrier of the transmission data according to the transmission data required by different transmission rates correspondingly using BPSK, QPSK, 16QAM or 64QAM modulation, and normalize the mapping of all modulations;

The receiving part module 12 is used to receive a complex signal containing in-phase and quadrature components. According to the modulation mapping relationship used during modulation, when the complex signal falls in the corresponding rectangular area, the corresponding symbol is determined to be recovered. the original transmission data.

Optionally, in another embodiment of the carrier processing device based on the air-ground joint interference system, the device further includes:

The pilot module is used to insert a pilot signal in the frequency domain of the modulated carrier spectrum, as a carrier synchronization signal, and transform the transmission data from frequency to time domain signal through fast Fourier transform;

The compensation module is used to receive the piloted carrier synchronization signal, and transform the time domain signal into a frequency domain signal through fast Fourier transform, extract the pilot frequency according to the frequency domain signal, and estimate the carrier frequency through the pilot frequency offset, and compensate the received signal in the time domain according to the carrier frequency offset.

Optionally, in another embodiment of the carrier processing device based on the air-ground joint interference system, the compensation module specifically includes:

Carrier frequency offset estimation unit for wide range carrier frequency offset estimation including integer carrier frequency offset using acquisition mode and fine carrier frequency offset estimation using tracking mode.

Optionally, in another embodiment of the carrier processing device based on the air-ground joint interference system, the device further includes:

A training symbol embedding module, used to embed specific training symbols in the transmission data in advance;

The channel estimation and equalization module is used for estimating the frequency response of the channel, and performing channel estimation and equalization on each data symbol in the carrier by using the received training symbols.

Optionally, in another embodiment of the carrier processing device based on the air-ground joint interference system, the device further includes:

The frequency point sensing module is used to periodically sense the frequency points within a certain frequency band to know whether the current spectrum is being used by equipment, and record the undisturbed frequency points;

The detection and processing module is used to detect whether the preset ad hoc network link interruption condition is met according to the undisturbed frequency point, and if so, interrupt the link or uniformly change the frequency of the entire network, wherein the entire network Unified frequency change means that the preset anti-jamming remote control link sends an instruction to change frequency to the ad hoc communication network of the entire air-ground joint jamming system.

Optionally, in another embodiment of the carrier processing device based on the air-ground joint interference system, the device further includes:

The peak-to-average ratio reduction module is used to reduce the peak value of the transmitted signal in the time domain through the fast Fourier transform through the peak-to-average power ratio reduction strategy based on clipping and filtering, and limit the maximum amplitude of the transmitted signal to a predetermined value. Set the specified range.

Optionally, in another embodiment of the carrier processing device based on the space-ground joint interference system, the peak-to-average power ratio reduction strategy based on clipping and filtering is to use clipping near the peak value of the transmitted signal in the time domain Or nonlinear saturation to reduce the peak-to-average power ratio, the peak-to-average ratio reduction module specifically includes:

The peak-to-average ratio reduction processing unit is used to transmit data from the frequency domain to the time domain, after the processing of the first-level limiting, the first phase compensation and the BPF filter module, and continue to go through the second-level limiting and second phase compensation and the processing of the LPF filter module, so that the obtained time domain signal is output to the radio frequency end.

It should be noted that the device in the embodiment of the present invention can be used to realize all the technical solutions in the above method embodiment, and the functions of each functional module can be realized according to the method in the above method embodiment, and the specific implementation process can refer to Relevant descriptions in the above examples will not be repeated here. Figure 2 above describes in detail the carrier processing device based on the air-ground joint interference system in the embodiment of the present invention from the perspective of the modularized functional entity, and the carrier processing device based on the air-ground joint interference system in the embodiment of the present invention is described below from the perspective of hardware processing A detailed description.

Fig. 3 is a schematic structural diagram of a carrier processing device based on a joint space-ground interference system provided by an embodiment of the present invention. The carrier processing device 300 based on a joint space-ground interference system may have relatively large differences due to different configurations or performances, and may include One or more processors (central processing units, CPU) 301 (for example, one or more processors) and memory 309, one or more storage media 308 for storing application programs 307 or data 306 (for example, one or more storage device). Wherein, the memory 309 and the storage medium 308 may be temporary storage or persistent storage. The program stored in the storage medium 308 may include one or more modules (not shown in the figure), and each module may include a series of instruction operations stored in Boolean variable storage for graph calculation. Furthermore, the processor 301 may be configured to communicate with the storage medium 308, and execute a series of instruction operations in the storage medium 308 on the carrier processing device 300 based on the air-ground joint interference system.

The carrier processing device 300 based on the air-ground joint interference system may also include one or more power supplies 302, one or more wired or wireless network interfaces 303, one or more input and output interfaces 304, and/or, one or more operating systems 305, such as Windows Server, Mac OS X, Unix, Linux, FreeBSD, etc. Those skilled in the art can understand that the carrier processing device structure based on the joint space-ground interference system shown in Figure 3 does not constitute a limitation on the carrier processing device based on the joint space-ground interference system, and may include more or less components, or combinations of certain components, or different arrangements of components.

Those skilled in the art can clearly understand that for the convenience and brevity of the description, the specific working process of the above-described system, device and unit can refer to the corresponding process in the foregoing method embodiment, which will not be repeated here.

In the several embodiments provided by the present invention, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or May be integrated into another system, or some features may be ignored, or not implemented. In another point, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of devices or units may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, each unit may exist separately physically, or two or more units may be integrated into one unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.

If the integrated unit is realized in the form of a software function unit and sold or used as an independent product, it can be stored in a computer-readable storage medium, and the computer-readable storage medium can be non-volatile or can be is volatile. Based on this understanding, the essence of the technical solution of the present invention or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium , including several instructions to make a computer device (which may be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (read-only memory, ROM), random access memory (random access memory, RAM), magnetic disk or optical disk, and other media capable of storing program codes.

As mentioned above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still understand the foregoing The technical solutions recorded in each embodiment are modified, or some of the technical features are replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims (10)

1. A carrier processing method based on an air-ground combined interference system is characterized by comprising the following steps:

in the transmitter part, according to the transmission data required by different sending rates, the carrier wave of the transmission data is correspondingly modulated by using BPSK, QPSK, 16QAM or 64QAM modulation modes, and all the modulated mappings are normalized;

in the receiver part, a complex signal containing in-phase and orthogonal components is received, and when the complex signal falls in a corresponding rectangular area according to a modulation mapping relation used in modulation, a corresponding code element is judged to be recovered original transmission data.

2. The method for processing carriers based on the air-ground joint interference system according to claim 1, further comprising:

in the transmitter section, a pilot signal is inserted in the frequency domain of the modulated carrier spectrum as a carrier synchronization signal, and transmission data is converted from frequency to a time domain signal by fast fourier transform;

in the receiver part, a carrier synchronization signal which is subjected to pilot frequency is received, a time domain signal is transformed into a frequency domain signal through fast Fourier transform, the pilot frequency is extracted according to the frequency domain signal, carrier frequency deviation is estimated through the pilot frequency, and the received signal is compensated in the time domain according to the carrier frequency deviation.

3. The method for processing carriers based on the air-ground combined interference system according to claim 2, wherein the estimating a carrier frequency offset through the pilot frequency specifically includes:

a wide range of carrier frequency offset estimates, including integer carrier frequency offsets, is performed using the acquisition mode and a fine carrier frequency offset estimate is performed using the tracking mode.

4. The method for processing carriers based on the air-ground combined interference system according to claim 1, further comprising:

at a transmitter portion, embedding a specific training symbol in the transmission data in advance;

in the receiver portion, to estimate the frequency response of the channel, each data symbol in the carrier is channel estimated and equalized using the received training symbols.

5. The method for processing carriers based on the air-ground joint interference system according to claim 1, further comprising:

in a receiver part, whether the current frequency spectrum is used by equipment is known by periodically sensing frequency points in a certain frequency band range, and the undisturbed frequency points are recorded;

and detecting whether a preset Ad hoc network link interruption condition is met or not according to the undisturbed frequency point, if so, interrupting the link or carrying out whole network unified frequency conversion, wherein the whole network unified frequency conversion means that a preset anti-interference remote control link sends a frequency conversion instruction to an Ad hoc network communication network of the whole air-ground combined interference system.

6. The method for processing carriers based on the air-ground joint interference system according to claim 2, further comprising:

in the transmitter section, the peak value of the transmission signal in the time domain is reduced by a peak-to-average power ratio reduction strategy based on clipping and filtering, and the maximum amplitude of the transmission signal is limited to a preset specified amplitude.

7. The method according to claim 6, wherein the clipping and filtering based peak-to-average power ratio reduction strategy is to reduce the peak-to-average power ratio by clipping or nonlinear saturation near the peak of the time-domain transmission signal, and specifically comprises:

after the transmission data change from the frequency to the time domain, the transmission data are processed by a first-stage amplitude limiting module, a first phase compensation module and a BPF filtering module, and are continuously processed by a second-stage amplitude limiting module, a second phase compensation module and an LPF filtering module, so that the obtained time domain signal is output to a radio frequency end.

8. An apparatus for processing carrier based on air-ground joint interference system, the apparatus comprising:

a transmitting part module, configured to modulate a carrier of the transmission data correspondingly in a BPSK, QPSK, 16QAM, or 64QAM modulation manner according to transmission data required by different sending rates, and normalize mapping of all modulations;

and the receiving part module is used for receiving the complex signal containing the in-phase component and the orthogonal component, and judging the corresponding code element as recovered original transmission data when the complex signal falls in a corresponding rectangular area according to a modulation mapping relation used in modulation.

9. The carrier processing device based on the air-ground joint interference system is characterized by comprising a memory and at least one processor, wherein the memory stores instructions, and the memory and the at least one processor are interconnected through a line; the at least one processor invokes the instructions in the memory to cause the carrier processing device of the air-ground based joint interference system to execute the carrier processing method of the air-ground based joint interference system according to any one of claims 1 to 7.

10. A computer-readable storage medium, on which a computer program is stored, wherein the computer program, when being executed by a processor, implements the carrier processing method of the air-ground based joint interference system according to any one of claims 1 to 7.

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