A frequency hopping communication signal receiving method and device

Abstract

A frequency hopping communication signal receiving method, comprising: performing parameter configuration; performing energy detection on a radio frequency signal, when the detected energy is greater than the upper limit threshold of a threshold comparator, the received signal passes through an overload protection attenuator; when the detected energy is less than the lower limit threshold of the threshold comparator, the received signal bypasses the overload protection attenuator; after performing receiving frequency switching, the average power of the channel receiving signal in the T3 time period is calculated according to the sample count value N1 within the set T3, the channel receiving field strength is calculated according to the average power; the receiving field strength is compared with the upper limit threshold value and the lower limit threshold value respectively, and the variable attenuator attenuation value and the variable gain amplifier amplification coefficient are adjusted according to the comparison result; the amplitude value of the maximum sample in all received samples is calculated according to the sample count value N2 within the set T4, the digital gain adjustment value is calculated, then the multiplication coefficient is read from the table, the digital signal gain is adjusted, and the stable IQ data is output.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of wireless communication, more particularly, to a frequency hopping communication signal receiving method and device, which is suitable for burst communication protocol receiver terminal. BACKGROUND

[0002] In a wireless communication system, radio signals are affected by various factors such as transmitting power, transmission distance, climate environment, geographical environment, electromagnetic environment, carrier frequency and multipath effect during propagation, resulting in real-time changes in radio signal strength, signal-to-noise ratio and interference signals received by the receiver. However, the link layer, network layer and application layer of the communication system need stable power, high signal-to-noise ratio digital signals in protocol analysis such as synchronous search and correlation value calculation to prevent false alarms and false synchronization capture. Therefore, the communication system requires the receiver physical layer to have the ability to convert the received radio signals with large dynamic range into stable signal output. The reception of non-continuous burst signals with high demodulation sensitivity has high technical requirements for the automatic gain control (AGC) dynamic range, noise coefficient, anti-interference ability and convergence rate of the receiver. In engineering applications, when the automatic gain control (AGC) dynamic range of the receiver is designed to be large, the system convergence time will be long and the signal-to-noise ratio will deteriorate; when the system convergence time is short and the signal-to-noise ratio deteriorates to a low degree, the dynamic range that the receiver can reach is often small. It is difficult to achieve superior performance in all indicators in system design.

[0003] In addition, in the design of a radio signal receiver, continuous carrier communication signal carrier reception has continuity, and the signal convergence speed requirement is not high, so the communication system receiver has good performance for receiving continuous carrier communication signals. However, with the development of wireless communication technology, to adapt to complex communication environment, prevent frequency point interference from affecting communication performance, and prevent enemy interception from affecting communication security, frequency hopping communication technology has emerged. The frequency hopping communication system can effectively avoid frequency point interference and prevent cracking interception. Different communication systems have different frequency hopping rates. For example, in the case of ultra-short wave frequency band communication, communication systems with frequency hopping rates from 500 hops per second to 5000 hops per second exist, and even some communication systems are designed with frequency hopping rates greater than 10,000 hops per second. At the same time, the receiving sensitivity of communication systems with good algorithms can even reach -130 dB. However, the characteristics of frequency hopping communication increase the design difficulty of the receiver. In the reception of high-speed frequency hopping data, the receiver needs to control the frequency hopping filter, mixer, automatic gain control (AGC) and other functional units, which results in a very short time for channel processing in each hop, often only a few tens of microseconds, or even shorter. Moreover, due to the requirement of receiving sensitivity, the receiver is required to have a large dynamic receiving range.

[0004] In view of the above-mentioned defects, the application combines the characteristics of burst communication signals, frequency hopping communication and continuous phase modulation (CPM) signals with constant envelope, and designs a burst communication signal receiving method and device suitable for continuous phase modulation (CPM) frequency hopping communication and similar communication characteristics, which has the characteristics of large receiving dynamic range, small noise coefficient, strong anti-interference ability, fast convergence rate, less data calculation and easy engineering implementation, and is applied in engineering practice. SUMMARY

[0005] The application aims to overcome at least one of the above-mentioned defects of the prior art, and provides a frequency hopping communication signal receiving method and device for achieving the effects of large receiving dynamic range, small noise coefficient, strong anti-interference ability, fast convergence rate and less data calculation and easy engineering implementation in burst communication signal receiving.

[0006] In a first aspect, the technical solution adopted by the application is a frequency hopping communication signal receiving method, which comprises:

[0007] S1: dividing the time domain characteristics of the frequency hopping communication signals obtained by continuously switching the transceiving frequencies of the transceiver into characteristic time periods, and dividing them into five characteristic time periods T1, T2, T3, T4 and T5, wherein T1 represents the time of transmitting data at each frequency point, T2 represents the frequency switching time, T3 represents the power rising time and AGC control time of receiving data at each hop, T4 represents the digital gain adjustment time, and T5 represents the target IQ sample number calculation time; then, parameter configuration is performed on the upper and lower threshold values, the sample count value N1 in T3, the sample count value N2 in T4 and the digital gain adjustment count value;

[0008] S2: after completing the parameter configuration, energy detection is performed on the radio frequency signals, and when the detected energy is greater than the upper threshold of the threshold comparator, the received signals pass through the overload protection attenuator; when the detected energy is less than the lower threshold of the threshold comparator, the received signals bypass the overload protection attenuator;

[0009] S3: after the receiving frequency is switched, the average power of the channel receiving signals in the T3 time period is calculated according to the set sample count value N1 in T3, and the channel receiving field strength is calculated according to the average power, which is used to adjust the analog signal AGC;

[0010] S4: comparing the receiving field strength with the upper threshold and the lower threshold respectively, and adjusting the attenuation value of the variable attenuator and the amplification coefficient of the variable gain amplifier according to the comparison results, so as to realize the adjustment of the gain of the analog signal through the device control of the channel unit;

[0011] S5: According to the set sample count value N2 within T4, the amplitude value of the maximum sample in all received samples is calculated, then the digital gain adjustment value is calculated, then the multiplication coefficient G is read by table lookup, the digital signal gain is adjusted, and the stable IQ data is outputted.

[0012] In the application, the energy detection by the radio frequency signal can effectively prevent the front-end circuit from being damaged by the excessive signal input, the AGC control parameter of the receiver is calculated, the channel received field strength is calculated within the T3 time period to adjust the gain of the analog signal, the amplitude value of the maximum sample is calculated within the T4 time period to adjust the gain of the digital signal, the influence of the out-of-band interference on the AGC control is minimized, the anti-interference ability of the receiver is improved, meanwhile, the multiplication coefficient of the gain control is obtained by the table lookup, the calculation complexity of the system is greatly reduced, and the engineering implementation is easy. In addition, the method provided by the application can effectively ensure that the signal-to-noise ratio of the received data is not deteriorated while the gain adjustment degree is high, the time for the channel control is short, the convergence speed is fast, and the receiving requirement of the frequency hopping signal is met.

[0013] Preferably, in the step S3, the average power of the channel received signal within the T3 time period is calculated according to the set sample count value N1 within the T3 time period, and the channel received field strength is calculated according to the average power, which comprises:

[0014] S31: The I-channel signal amplitude of the output signal after the different field strength signals pass through the receiving device is calibrated by using the standard equipment;

[0015] S32: The relationship curve between the field strength and the signal strength is fitted by using the matlab software, the corresponding field strength values of the different signal amplitudes are stored in the ROM0 in the form of the lookup table, so that the field strength value of the signal is quickly looked up according to the result of the accumulated average in the signal receiving.

[0016] Further preferably, in the S32, the fitting formula of the relationship curve between the field strength and the signal strength fitted by using the matlab software is:

[0017] f(x)=axb+c

[0018] Wherein, f(x) is the field strength, x is the average amplitude of the I-channel signal within the T3 time period, a, b, c are the values fitted by using the test sample.

[0019] Therefore, in the application, the average field strength is calculated by fitting the relationship formula between the average amplitude and the field strength, and the multiplication coefficient of the gain control is obtained by the table lookup, so that the calculation complexity of the system is greatly reduced, and the engineering implementation is easy.

[0020] Preferably, the step S4 comprises:

[0021] When the received field strength is compared with the upper limit threshold value, if the received field strength is greater than the set upper limit threshold value, the amplification coefficient of the variable gain amplifier is reduced, and when the amplification coefficient cannot meet the received attenuation requirement, the variable attenuator is adjusted to increase the attenuation value; if the received field strength is less than the set upper limit threshold value, the operation of step S5 is directly performed;

[0022] When the received field strength is compared with the lower limit threshold value, if the received field strength is less than the set lower limit threshold value, the variable attenuator is adjusted to reduce the attenuation value, and when the attenuation value of the variable attenuator cannot meet the attenuation requirement, the variable gain amplifier is adjusted to increase the amplification coefficient; if the received field strength is greater than the set lower limit threshold value, the operation of step S5 is directly performed.

[0023] By adjusting the relevant control parameters according to the comparison results, the influence of the out-of-band interference gain control can be reduced to the greatest extent, and the anti-interference capability of the receiver is effectively improved.

[0024] Preferably, in the step S5, the multiplication coefficient G corresponding to the target value of the amplitude value of different signals is calibrated and stored in the ROM1 in the form of a lookup table, the multiplication coefficient G of adjustment is directly read after the amplitude value of the maximum sampling point of the signal is calculated in the signal receiving process in the T4 time period, and then the target IQ sample number is obtained by multiplication through the multiplier and the input signal in the T5 time period, so that the stable IQ data is output.

[0025] Further preferably, in the step S5, the relationship curve between the target amplitude value and the multiplication coefficient is fitted by using the matlab software, and the fitting formula corresponding to the fitted relationship curve is:

[0026] A0=G×A1

[0027] Wherein, A0 is the target amplitude value of the received signal of the whole system, A1 is the amplitude value of the maximum sampling point calculated in the T4 time period, and G is the multiplication coefficient.

[0028] In the present application, the coefficient multiplication method for digital signals is used to adjust the signal gain, instead of the simple data clipping method for gain adjustment, so that the present application has high gain adjustment precision and does not deteriorate the signal-to-noise ratio of the received data.

[0029] On the other hand, the present application also provides a frequency hopping communication signal receiving device, which comprises a channel control unit and a baseband processing unit.

[0030] The channel control unit is composed of a radio receiving antenna, a frequency hopping filter, an overload protection attenuator, a threshold comparator, a radio frequency signal detector, a mixer, an intermediate frequency filter, a variable gain amplifier, a DAC converter and a digital control attenuator;

[0031] The baseband processing unit is composed of an ADC conversion chip for analog-digital conversion of the received communication signal and a digital signal processing chip; the digital signal processing chip contains a DDC digital down converter, a digital filter, a digital gain adjuster, a plurality of sample point counters, a plurality of average power calculators, a channel control parameter calculator, a gain adjustment value calculator and a burst signal receiving controller;

[0032] In the channel control unit, the signal received by the radio receiving antenna is processed in sequence by the frequency hopping filter, the overload protection attenuator, the mixer, the intermediate frequency filter, the variable gain amplifier and the digital control attenuator;

[0033] The channel control unit further comprises a detector, a threshold comparator and a DAC converter; the signal needs to be detected by the detector before entering the overload protection attenuator, for preventing damage of the device caused by input of a too large signal; the threshold comparator is connected between the detector and the overload protection attenuator, for comparing the energy of the signal, and then the overload protection attenuator receives the comparison result to make corresponding parameter adjustment; the DAC converter is connected with the burst signal receiving controller in the baseband processing unit and the variable gain amplifier, for receiving the control parameters and converting the input digital signal into a corresponding analog signal, and then the parameter adjustment is made by the variable gain amplifier and the digital control attenuator;

[0034] In the baseband processing unit, the ADC conversion chip converts the signal input from the channel control unit into an analog signal, and then the signal enters the DDC digital down converter and the digital filter in sequence to be down-converted and digitally filtered, and then enters the corresponding calculators to calculate the maximum sample point amplitude value and the digital gain adjustment value, and finally the obtained gain adjustment value is input into the digital gain adjuster to make gain adjustment, and finally the stable IQ data is input.

[0035] In the receiving device provided in the application, the channel control unit is used to make corresponding parameter adjustment on the input frequency hopping signal, and then the baseband processing unit is used to process the adjusted signal, so that the dynamic range of the ADC conversion chip is fully utilized, the digital signal is amplified after analog-digital conversion, the channel gain is reduced, the noise coefficient is reduced, all the control of the received signal is based on the data from the rear end of the digital filter, the gain error control caused by the adjacent channel interference is effectively prevented, and the anti-interference ability of the receiver is improved.

[0036] Preferably, the variable gain amplifier is a low-voltage-controlled low-noise amplifier, and the maximum gain is 50dBm.

[0037] Preferably, the threshold value of the threshold comparator ranges from 9dBm to 11dBm.

[0038] Preferably, the dynamic range of the ADC conversion chip is from -80dBm to -20dBm.

[0039] In the present application, the maximum gain of the system is 50dBm, the minimum input signal of the ADC conversion chip is -80dBm, therefore, when the input signal strength is -130dBm, the signal input to the ADC conversion chip is -80dBm through 50dBm gain adjustment; the maximum attenuation value of the digital attenuator is 60dBm, and the system has an attenuation capability of about 40dBm for the input strong signal after subtracting the gain inherent to the receiving device; the maximum undistorted input signal strength allowed by the ADC conversion chip is -20dBm, and the maximum input signal can theoretically reach 20dBm, therefore, the dynamic range of the whole system receiving gain can theoretically reach -130dBm to 20dBm, but due to the limitation of the transmitter power, the maximum signal strength received by the system is about 10dBm, therefore, in the present device, the channel low-noise maximum gain only needs to be 50dB in the case of realizing the signal receiving capability in the dynamic range of -130dBm to 10dBm, and the influence on the system noise is small.

[0040] Compared with the prior art, the present application has the following beneficial effects:

[0041] (1) In the present application, the T4 period uses the method of multiplying the use coefficient of the digital signal to adjust the signal gain, instead of simply performing the bit clipping processing on the data, and has high gain adjustment precision, and does not deteriorate the signal-to-noise ratio of the received data.

[0042] (2) In the present application, the channel low-noise maximum gain only needs to be 50dB in the case of realizing the signal receiving capability in the dynamic range of -130dBm to 10dBm, and the influence on the system noise is small.

[0043] (3) The present application has short time for channel control, and fast convergence speed, and meets the demand of frequency hopping signal receiving. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 The flowchart of the frequency hopping communication signal receiving method provided by the present application is shown.

[0045] Figure 2 The frequency hopping signal and the processing time of each stage provided by the present application are shown.

[0046] Figure 3The structure schematic diagram of the frequency hopping communication signal receiving device provided by the application is shown. DETAILED DESCRIPTION

[0047] The drawings of the application are only used for illustrative description and cannot be understood as the limitation of the application. In order to better illustrate the following embodiments, some components of the drawings are omitted, enlarged or reduced, and do not represent the size of the actual product; it is understandable for those skilled in the art that some well-known structures and their descriptions in the drawings can be omitted.

[0048] Embodiment 1

[0049] In the prior art, the paper "Constant Envelope Waveform Digital AGC Algorithm Based on FPGA" discloses the use of the characteristics of constant envelope communication waveform to independently calculate the signal energy of each sampling point, and the receiving intensity of the digital signal is adjusted by the clipping method in the signal down-conversion process. This method processes the data at the back end of the digital filter to make the system have certain anti-interference performance, but the use of the clipping method to adjust the data cannot finely adjust the link data. In the patent "Automatic Gain Control Circuit and Control Method of Ultra-short Wave Radio Station", the method of using the analog signal detection of the radio frequency front end signal and the digital signal detection after the analog-to-digital conversion is disclosed to adjust the analog signal of the signal receiving path, and a receiving path dynamic range of up to 140dB is realized. However, using the analog quantity of the radio frequency signal front end as the judgment condition of AGC adjustment often reduces the anti-interference ability of the system. At the same time, under the condition that the ADC receiving chip has a 60dB dynamic receiving range, the method still needs a channel with an 80dB receiving gain. The excessive receiving gain of the channel deteriorates the signal-to-noise ratio of the received signal and reduces the sensitivity of the system reception. Secondly, in the patent "All-digital open-loop automatic gain control method and device for burst communication", the energy of the received burst signal is calculated by using all-digital signal to make the system have certain anti-interference performance. However, the signal receiving dynamic range of the system is not specified in detail, and at least 20 sampling points are needed for the control convergence, which has a long convergence time and is difficult to meet the signal receiving requirements of the fast frequency hopping communication system.

[0050] The embodiment provides a frequency hopping communication signal receiving method. Figure 1 As shown in the figure, Figure 1 The flowchart of the frequency hopping communication signal receiving method provided by the embodiment is shown. The method comprises the following steps:

[0051] In step S1, the time domain characteristics of the frequency hopping communication signal obtained by continuously switching the receiving and transmitting frequency of the transceiver are divided into characteristic time periods, as shown in the figure. Figure 2 As shown in the figure, Figure 2 The frequency hopping signal and the processing time of each stage provided by the embodiment are shown. Figure 2As can be seen, the characteristic time periods obtained by the division include five characteristic time periods T1, T2, T3, T4 and T5, wherein T1 represents the time of data transmission of each frequency point, T2 represents the switching frequency time, during which the devices related to the frequency hopping control such as the frequency hopping filter and the mixer are mainly controlled, and the transceiving of the whole channel is in the blanking state; T3 represents the power rising time and AGC control time of data reception of each hop, T4 represents the calculation digital gain adjustment time, and T5 represents the calculation target IQ sample point number time; wherein (T3+T4) is the channel processing time of each hop signal, which is relatively short in the waveform algorithm of the ultrashort wave frequency hopping communication, and the design length is often less than 30 sample point symbols. The time is different at different symbol rates, but is often less than 100us. To ensure the reliable reception of each hop data, the control parameters of the receiver must be adjusted within the time period of (T3+T4).

[0052] Then, the parameter configuration is performed on the upper and lower limit threshold values, the sample point count value N1 in T3, the sample point count value N2 in T4 and the digital gain adjustment count value. The upper and lower limit threshold values include the radio frequency comparison upper and lower limit threshold values and the channel AGC upper and lower limit threshold values.

[0053] Preferably, after the parameter configuration is completed in the step S2, the energy detection of the radio frequency signal is continuously performed by using the detector. When the detected energy is greater than the radio frequency comparison upper limit threshold of the threshold comparator, the received signal passes through the overload protection attenuator. When the detected energy is less than the radio frequency comparison lower limit threshold of the threshold comparator, the received signal bypasses the overload protection attenuator.

[0054] Preferably, after the receiving frequency is switched in the step S3, the average power of the channel received signal in the T3 time period is calculated according to the set sample point count value N1 in T3, and the channel received field strength is calculated according to the average power.

[0055] Since the square and square root calculation is involved in the average power calculation formula, the square and square root operation of the average power is not easy to implement in the FPGA, occupies more resources and has a long calculation period. Therefore, the following steps are used to solve the above problems in the calculation in the T3 time period of the step S3:

[0056] In step S31, the I path signal amplitude output by the receiving device after the different field strength signals pass through the receiving device is calibrated by using the standard equipment.

[0057] In step S32, the relationship curve between the field strength and the signal strength is fitted by using the matlab software, and the corresponding field strength values of different signal amplitudes are stored in the ROM0 in the form of a lookup table. Therefore, the field strength value of the signal can be quickly found according to the result of the accumulated average in the signal reception, and the complex calculation is avoided.

[0058] Further preferably, in the step S32, the fitting formula of the relationship curve between the field intensity and the signal intensity is fitted by using the matlab software, and is as follows:

[0059] f(x))=a+c

[0060] Wherein, f(x) is the field intensity, x is the average amplitude of the I path signal in the T3 time period, and a, b, c are the values fitted by using the test sample.

[0061] Therefore, in the embodiment, the values of a, b, c are fitted by using the test sample according to the fitting formula, and then the average amplitude x and the value of the field intensity f(x) are calculated according to the formula with the accuracy of 0.25dBm, and the corresponding f(x) value is stored in the ROM0. Since the dynamic range of the whole system is -130dBm-10dBm, the data storage length is 560, and the data amount is not large, so the calculation complexity is effectively reduced, and the engineering implementation is easy.

[0062] Preferably, in the step S4, the received field intensity value calculated in the step S3 is compared with the channel AGC upper limit threshold value and the channel AGC lower limit threshold value respectively, and the variable attenuator attenuation value and the variable gain amplifier amplification coefficient are adjusted according to the comparison result, so as to adjust the gain of the analog signal by using the received field intensity.

[0063] Specifically, when the received field intensity is compared with the channel AGC upper limit threshold value, if the received field intensity is greater than the set channel AGC upper limit threshold value, the variable gain amplifier amplification coefficient is reduced, and when the amplification coefficient is reduced and still cannot meet the received attenuation requirement, the variable attenuator is adjusted to increase the attenuation value; if the received field intensity is less than the set channel AGC upper limit threshold value, the operation of the step S5 is directly performed.

[0064] When the received field intensity is compared with the channel AGC lower limit threshold value, if the received field intensity is less than the set channel AGC lower limit threshold value, the variable attenuator is adjusted to reduce the attenuation value, and when the attenuation value of the variable attenuator is adjusted and still cannot meet the attenuation requirement, the variable gain amplifier is adjusted to increase the amplification coefficient; if the received field intensity is greater than the set channel AGC lower limit threshold value, the operation of the step S5 is directly performed.

[0065] The embodiment can reduce the influence of the out-of-band interference gain control to the greatest extent and effectively improve the anti-interference ability of the receiver by adjusting the relevant control parameters according to the comparison result of the received field intensity and the channel AGC threshold value.

[0066] Preferably, in the step S5, the amplitude value of the maximum sample point in all received samples is calculated according to the sample count value N2 within the set T4, then the digital gain adjustment value is calculated, then the multiplication coefficient is read by table lookup, the digital signal gain is adjusted, and the stable IQ data is output.

[0067] Specifically, in the step S5, referring to the method within the T3 period, the multiplication coefficient G corresponding to the target value of the amplitude value of different signals is calibrated within the T4 period, and then is stored in the ROM1 in the form of table lookup, the amplitude value of the maximum sampling point of the signal is calculated during the signal receiving process within the T4 period, so that each sample is not distorted during the adjustment of the digital gain, then the adjusted multiplication coefficient G is directly read, and then is multiplied with the input signal by the multiplier within the T5 period, so that the target IQ sample number is obtained, thereby the stable IQ data is output. The multiplier is directly realized by using the IP core of the FPGA.

[0068] Further preferably, in the step S5, the relationship curve between the target amplitude value and the multiplication coefficient is fitted by using the matlab software, and the fitting formula corresponding to the fitted relationship curve is:

[0069] A0=G×A1

[0070] Wherein, A0 is the target amplitude value of the received signal of the whole system, A1 is the amplitude value of the maximum sampling point calculated within the T4 period, and G is the gain coefficient.

[0071] In the present application, the gain of the signal is adjusted by using the method of multiplying the digital signal by the coefficient, rather than using the method of simply performing the clipping processing on the data to adjust the gain, so that the present application has higher gain adjustment precision, and the signal-to-noise ratio of the received data is not deteriorated.

[0072] Embodiment 2

[0073] The present embodiment provides a frequency hopping communication signal receiving device, as shown in Figure 3 , Figure 3 The frequency hopping communication signal receiving device provided by the present embodiment is shown in the structure diagram, and from the diagram, it can be seen that the device comprises a channel control unit and a baseband processing unit; wherein the channel control unit is mainly realized by a hardware circuit, and the baseband processing unit is mainly realized by a digital signal processing chip such as FPGA.

[0074] The channel control unit is composed of a radio receiving antenna, a frequency hopping filter, an overload protection attenuator, a threshold comparator, a radio frequency signal detector, a mixer, an intermediate frequency filter, a variable gain amplifier, a DAC converter and a digital control attenuator;

[0075] The baseband processing unit is composed of an ADC conversion chip for analog-digital conversion of a received communication signal and a digital signal processing chip; the digital signal processing chip contains a DDC digital down converter, a digital filter, a digital gain adjuster, a plurality of sample point counters, a plurality of average power calculators, a channel control parameter calculator, a gain adjustment value calculator and a burst signal reception controller;

[0076] In the channel control unit, a signal received by a radio receiving antenna is processed in sequence by a frequency hopping filter, an overload protection attenuator, a mixer, an intermediate frequency filter, a variable gain amplifier and a digital control attenuator.

[0077] The channel control unit further comprises a detector, a threshold comparator and a DAC converter.

[0078] The detector is arranged between the frequency hopping filter and the overload protection attenuator, and the signal needs to be detected by the detector before entering the overload protection attenuator, so as to prevent the device circuit from being damaged due to input of an excessively large signal.

[0079] The threshold comparator is connected between the detector and the overload protection attenuator, and is used for energy comparison of the signal, and then the overload protection attenuator receives the comparison result to make corresponding parameter adjustment; in the strongest case of the received signal, the receiver receives a signal strength of about 10 dBm, therefore, the threshold value of the threshold comparator is set to 10 dBm±1 dBm, i.e. the range is 9 dBm-11 dBm.

[0080] The DAC converter is connected with the burst signal reception controller in the baseband processing unit and the variable gain amplifier, and is used for receiving control parameters and converting the input digital signal into a corresponding analog signal, and then the parameter adjustment is made by the variable gain amplifier and the digital control attenuator; the variable gain amplifier is a voltage-controlled low-noise amplifier, and the maximum gain value is 50 dBm, i.e. the gain value of the entire channel is 50 dBm; the maximum attenuation value of the digital control attenuator is 60 dBm, and the control precision is 0.25 dBm.

[0081] In the baseband processing unit, the ADC conversion chip performs analog-digital conversion on the signal transmitted from the channel control unit, wherein the dynamic range of the ADC conversion chip is-80 dBm- -20 dBm.

[0082] Then the signal enters the DDC digital down converter and the digital filter in sequence to perform down conversion and digital filtering, and then enters the corresponding calculators to perform maximum sample amplitude value and digital gain adjustment calculation, finally the obtained gain adjustment value is input into the digital gain adjuster to perform gain adjustment, and finally the stable IQ data is input.

[0083] In the receiving device provided in the application, the channel control unit is used to adjust the corresponding parameters of the input frequency hopping signal, and then the baseband processing unit is used to process the adjusted signal, so that the dynamic range of the ADC chip is fully utilized, the digital signal is amplified after analog-digital conversion, the channel gain is reduced, the noise coefficient is reduced, all the control basis of the received signal comes from the data after the digital filter rear end, the gain error control caused by the adjacent channel interference is effectively prevented, and the anti-interference ability of the receiver is improved.

[0084] Obviously, the above embodiments of the application are only examples for clearly illustrating the technical solutions of the application, and are not intended to limit the specific implementation manners of the application. Any modification, equivalent replacement and improvement made within the spirit and principle of the claims of the application should be included in the protection scope of the claims of the application.

Claims

1. A method for receiving a frequency hopping communication signal, characterized in that: The method comprises: S1: Divide the time domain characteristics of the frequency hopping communication signal obtained by continuously switching the transmit and receive frequencies of the transceiver into five characteristic time periods: T1, T2, T3, T4, and T5. T1 represents the time when data is sent at each frequency point, T2 represents the frequency switching time, T3 represents the power rise time and AGC control time for receiving data at each hop, T4 represents the time for calculating the digital gain adjustment, and T5 represents the time for calculating the target IQ sample count. Parameter configuration is then performed for the upper and lower limit thresholds, the sample count value N1 within T3, the sample count value N2 within T4, and the digital gain adjustment count value. S2: After completing the parameter configuration, the RF signal is energy detected. When the detected energy is greater than the upper threshold of the threshold comparator, the received signal passes through the overload protection attenuator. When the detected energy is less than the lower threshold of the threshold comparator, the received signal bypasses the overload protection attenuator. S3: After the receiving frequency is switched, the average power of the channel receiving signal in the T3 period is calculated according to the sample count value N1 set in T3, and the channel receiving field strength is calculated based on the average power; S4: Compare the received field strength with the upper threshold value and the lower threshold value respectively, and adjust the attenuation value of the variable attenuator and the amplification factor of the variable gain amplifier accordingly according to the comparison results, thereby adjusting the gain of the analog signal; S5: Calculate the amplitude value of the maximum sample point among all the received sample points according to the sample point count value N2 set in T4. Then the digital gain adjustment value is calculated, and then the multiplication coefficient G is read from the table to adjust the digital signal gain and output stable IQ data.

2. A method for receiving a frequency hopping communication signal according to claim 1, characterized in that: In the step S3, the step of calculating the average power of the channel received signal in the T3 time period according to the set sample count value N1 of the T3 time period, and calculating the channel received field strength according to the average power includes: S31: using standard equipment to calibrate the amplitude of the I-channel signal output after the different field strength signals pass through the receiving device; S32: Use MATLAB software to fit the relationship curve between field strength and signal strength, and store the corresponding field strength values ​​of different signal amplitudes in ROM0 in the form of a lookup table, so that the field strength value of the signal can be quickly found according to the result of cumulative averaging during signal reception.

3. A frequency hopping communication signal receiving method according to claim 2, characterized in that: In the S32, the fitting formula of the relationship curve between the field intensity and the signal intensity is fitted using the matlab software: Where f(x) is the field strength, x is the average amplitude of the I-channel signal during the T3 period, and a, b, and c are the values ​​fitted using the test samples.

4. A method for receiving a frequency hopping communication signal according to claim 3, characterized in that: The step S4 includes: When comparing the received field strength with the upper threshold value, if the received field strength is greater than the set upper threshold value, the variable gain amplifier amplification factor is reduced. If the reduced amplification factor still cannot meet the receiving attenuation requirement, the variable attenuator is adjusted to increase the attenuation value. If the received field strength is less than the set upper threshold value, the operation of step S5 is directly performed. When comparing the received field strength with the lower limit threshold value, if the received field strength is less than the set lower limit threshold value, the variable attenuator is adjusted to reduce the attenuation value. When the attenuation value of the variable attenuator cannot meet the attenuation requirement, the variable gain amplifier is adjusted to increase the amplification factor; if the received field strength is greater than the set lower limit threshold value, the operation of step S5 is directly performed.

5. A method for receiving a frequency hopping communication signal according to claim 4, characterized in that: Step S5 specifically includes: calibrating the multiplication coefficient G corresponding to the target value of the amplitude value of different signals, and storing it in ROM1 in a table lookup manner; after calculating the amplitude value of the maximum sampling point of the signal during the signal reception process in the T4 time period, directly reading the adjusted multiplication coefficient G; and then multiplying the input signal through a multiplier in the T5 time period to obtain the target number of IQ samples, thereby outputting stable IQ data.

6. A frequency hopping communication signal receiving method according to claim 5, characterized in that: Step S5 also includes fitting a relationship curve between the target amplitude value and the multiplication coefficient using Matlab software. The fitting formula corresponding to the fitted relationship curve is: Among them, A0 is the target amplitude value of the received signal of the entire system, A1 is the amplitude value of the maximum sampling point calculated within the T4 time period, and G is the multiplication coefficient.

7. A frequency hopping communication signal receiving device, characterized in that: A method for receiving a frequency hopping communication signal based on any one of claims 1 to 6, wherein the device comprises a channel control unit and a baseband processing unit; The channel control unit is composed of a radio receiving antenna, a frequency hopping filter, an overload protection attenuator, a threshold comparator, a radio frequency signal detector, a mixer, an intermediate frequency filter, a variable gain amplifier, a DAC converter and a digitally controlled attenuator; The baseband processing unit is composed of an ADC conversion chip for performing analog-to-digital conversion on received communication signals and a digital signal processing chip; the digital signal processing chip includes a DDC digital down converter, a digital filter, a digital gain adjuster, several sample counters, several average power calculators, a channel control parameter calculator, a gain adjustment value calculator and a burst signal receiving controller.

8. The frequency hopping communication signal receiving device according to claim 7, characterized in that: The variable gain amplifier is a low voltage controlled low noise amplifier with a maximum gain of 50dBm.

9. A frequency hopping communication signal receiving device according to any one of claims 7-8, characterized in that: The comparison threshold of the threshold comparator ranges from 9dBm to 11dBm.

10. The frequency hopping communication signal receiving device according to any one of claims 7 to 8, characterized in that: The dynamic range of the ADC conversion chip is -80dBm~-20dBm.

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