Frequency hopping communication signal receiving method and device

Abstract

The frequency hopping communication signal receiving method comprises the following steps: performing parameter configuration; performing energy detection on the radio frequency signal, and when the detected energy is greater than the upper threshold of the threshold comparator, enabling the received signal to pass through an overload protection attenuator; when the detected energy is smaller than the lower limit threshold of the threshold comparator, the received signal bypasses the overload protection attenuator; after the receiving frequency is switched, the average power of channel receiving signals in the time period T3 is calculated according to the set sampling point count value N1 in the time period T3, and the channel receiving field intensity is calculated according to the average power; respectively comparing the receiving field intensity with an upper limit threshold value and a lower limit threshold value, and correspondingly adjusting an attenuation value of a variable attenuator and an amplification coefficient of a variable gain amplifier according to a comparison result; and calculating the amplitude value of the maximum sample point in all the received sample points according to the set sample point count value N2 in the T4, calculating a digital gain adjustment value, then looking up a table to read a multiplication coefficient, adjusting the digital signal gain, and outputting stable IQ data.

Description

Technical Field

[0001] The present invention relates to the field of wireless communications, and more specifically, to a method and device for receiving a frequency hopping communication signal, which are applicable to a burst communication protocol receiver terminal. Background Art

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

[0003] In addition, in the design of radio signal receivers, since the continuous carrier communication signal carrier reception is continuous and the signal convergence speed is not required, the communication system receiver has good performance for the reception of continuous carrier communication signals. However, with the development of wireless communication technology, in order to adapt to the complex communication environment, prevent the communication performance from being affected by frequency interference, and affect the communication security due to enemy interception, frequency hopping communication technology has emerged. The frequency hopping communication system can effectively avoid frequency interference and prevent cracking and interception. Different communication systems have different frequency hopping rates. Taking ultra-short wave frequency band communication as an example, there are communication systems with frequency hopping rates ranging from 500 to 5000 hops per second, and some communication systems even have a frequency hopping rate of more than 10,000 hops per second. At the same time, the receiving sensitivity of the communication system with a good algorithm can even reach -130dB. However, the characteristics of frequency hopping communication increase the difficulty of receiver design. In the reception of high-speed frequency hopping data, the receiver needs to control the frequency hopping filter, mixer, automatic receiving gain control (AGC) and other functional units, which results in a very short time for channel processing in each hop data, often only 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 shortcomings, the present invention combines the characteristics of burst communication signals, frequency hopping communication and continuous phase modulation (CPM) with constant envelope signal characteristics, and designs a burst communication signal receiving method and device suitable for continuous phase modulation (CPM) frequency hopping communication and similar communication characteristics. The method and device have the characteristics of large receiving dynamic range, small noise coefficient, strong anti-interference ability, fast convergence rate, small amount of data calculation, and easy engineering implementation, and are applied in engineering practice. Summary of the invention

[0005] The present invention aims to overcome at least one defect (shortcoming) of the above-mentioned prior art and provides a method and device for receiving a frequency hopping communication signal, which is used to achieve the effects of large receiving dynamic range, small noise coefficient, strong anti-interference ability, fast convergence rate, small amount of data calculation and easy engineering implementation when receiving burst communication signals.

[0006] In a first aspect, the technical solution adopted by the present invention is a method for receiving a frequency hopping communication signal, the method comprising:

[0007] S1: The time domain characteristics of the frequency hopping communication signal obtained by continuously switching the receiving and transmitting frequencies of the transceiver are divided into five characteristic time periods, namely, T1, T2, T3, T4, and T5, wherein T1 represents the time for sending data at each frequency point, T2 represents the switching frequency time, T3 represents the power rise time and AGC control time for receiving each hop data, T4 represents the time for calculating the digital gain adjustment, and T5 represents the time for calculating the target IQ sample number; then, parameter configuration is performed, and the upper and lower limit thresholds, the sample count value N1 in T3, the sample count value N2 in T4, and the digital gain adjustment count value are configured;

[0008] 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.

[0009] 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 according to the average power, which is used to adjust the analog signal AGC;

[0010] 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 gain factor of the variable gain amplifier accordingly according to the comparison results, so as to adjust the gain of the analog signal by controlling the device of the channel unit;

[0011] 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 calculate the digital gain adjustment value, then look up the table to read the multiplication coefficient G, adjust the digital signal gain, and output stable IQ data.

[0012] In the present invention, energy detection through radio frequency signals can effectively prevent damage to the front-end circuit caused by excessive signal input, and by calculating the AGC control parameters of the receiver, the channel receiving field strength is calculated in the T3 time period to adjust the gain of the analog signal, and the amplitude value of the maximum sample point is calculated in the T4 time period to adjust the gain of the digital signal, thereby minimizing the influence of out-of-band interference on the AGC control and improving the anti-interference ability of the receiver. At the same time, the multiplication coefficient of the gain control is obtained by table lookup, which greatly reduces the calculation complexity of the system and is easy to implement in engineering. In addition, the method provided by the present invention also effectively ensures that the signal-to-noise ratio of the received data is not deteriorated while having a high gain adjustment degree, the time used for channel control is short, the convergence speed is fast, and the reception requirements of the frequency hopping signal are met.

[0013] Preferably, in the step S3, calculating the average power of the channel receiving signal in the T3 time period according to the set sample point count value N1 of the T3 time period, and calculating the channel receiving field strength according to the average power includes:

[0014] S31: using standard equipment to calibrate the amplitude of the I-channel signal output after the signals of different field strengths pass through the receiving device;

[0015] 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.

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

[0017] f(x)=axb+c

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

[0019] Therefore, in the present invention, the average field strength is calculated by producing a lookup table parameter by fitting the relationship formula between the average amplitude and the field strength, and the multiplication coefficient of the gain control is obtained by looking up the table, which greatly reduces the calculation complexity of the system and facilitates engineering implementation.

[0020] Preferably, the step S4 includes:

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

[0022] 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.

[0023] By adjusting the relevant control parameters accordingly according to the comparison result, 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, the step S5 specifically includes: calibrating the multiplication coefficient G of the target value corresponding to the amplitude value of different signals, and storing it in ROM1 in a table lookup manner, directly reading the adjusted multiplication coefficient G after calculating the amplitude value of the maximum sampling point of the signal during the signal reception process in the T4 time period, and then multiplying it with the input signal through a multiplier in the T5 time period to obtain the target IQ sample point number, thereby outputting stable IQ data.

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

[0026] A0=G×A1

[0027] 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 in the T4 time period, and G is the multiplication coefficient.

[0028] The present invention uses a method of multiplying digital signals by coefficients to adjust the signal gain, rather than using a method of simply truncating the data to adjust the gain, so that the present invention has a higher gain adjustment accuracy and does not deteriorate the signal-to-noise ratio of the received data.

[0029] On the other hand, the present invention also provides a frequency hopping communication signal receiving device, the device comprising 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 digitally controlled attenuator;

[0031] The baseband processing unit is composed of an ADC conversion chip and a digital signal processing chip for performing analog-to-digital conversion on received communication signals; the digital signal processing chip includes a DDC digital down converter, a digital filter, a digital gain adjuster, a plurality of sample 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 through a frequency hopping filter, an overload protection attenuator, a mixer, an intermediate frequency filter, a variable gain amplifier, and a digitally controlled attenuator;

[0033] The channel control unit also includes a detector, a threshold comparator and a DAC converter. Before the signal enters the overload protection attenuator, it needs to be detected by the detector to prevent the device from being damaged by excessive signal input; the threshold comparator is connected between the detector and the overload protection attenuator to compare the energy of the signal, and then the overload protection attenuator receives the comparison result and adjusts the corresponding parameters; the DAC converter is connected to the burst signal receiving controller and the variable gain amplifier in the baseband processing unit, and is used to receive the control parameters and convert the input digital signal into a corresponding analog signal, and then adjust the parameters through the variable gain amplifier and the digitally controlled attenuator;

[0034] In the baseband processing unit, the ADC conversion chip performs analog-to-digital conversion on the signal transmitted from the channel control unit, and then the signal enters the DDC digital down-converter and digital filter in turn for down-conversion and digital filtering, and then enters the corresponding calculator to perform amplitude value of the maximum sample point and digital gain adjustment calculation, and finally the obtained gain adjustment value is input into the digital gain adjuster for gain adjustment, and finally the stable IQ data is input.

[0035] In the receiving device provided in the present application, the channel control unit is first 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, fully utilizing the dynamic range of the ADC conversion chip, and amplifying the digital signal after analog-to-digital conversion to reduce the channel gain and the noise coefficient. All control bases of the received signal come from the data at the back end of the digital filter, effectively preventing the gain error control caused by adjacent channel interference and improving the anti-interference ability of the receiver.

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

[0037] Preferably, the threshold value range of the threshold comparator is 9dBm to 11dBm.

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

[0039] In the present application, the maximum gain of the system is 50dBm, and 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 a gain adjustment of 50dBm; the maximum attenuation value of the digitally controlled attenuator is 60dBm. When the received signal strength is very large, the inherent gain of the receiving device itself is subtracted, and the system has an attenuation capability of about 40dBm for the input strong signal. The maximum undistorted input signal strength allowed by the ADC conversion chip is -20dBm, and the maximum input signal can reach 20dBm in theory. Therefore, in theory, the dynamic range of the receiving gain of the entire system can reach -130dBm to 20dBm. However, due to the transmission power limitation of the transmitter, the maximum signal strength received by the system is about 10dBm. Therefore, in the present device, the signal receiving capability is realized in the dynamic range of -130dBm to 10dBm, and the maximum low-noise gain of the channel is only 50dB, which has little impact on the system noise.

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

[0041] (1) In the present invention, the signal gain is adjusted by multiplying the digital signal by a coefficient in the T4 period instead of simply truncating the data, which has a higher gain adjustment accuracy and does not deteriorate the signal-to-noise ratio of the received data.

[0042] (2) When the present invention realizes the signal receiving capability of -130dBm to 10dBm dynamic range, the maximum low-noise gain of the channel only needs 50dB, which has little impact on the system noise.

[0043] (3) The present invention takes a short time to control the channel and has a fast convergence speed, thus meeting the requirements for receiving frequency hopping signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 A schematic flow chart of a frequency hopping communication signal receiving method provided by the present invention.

[0045] Figure 2 This is a schematic diagram of the frequency hopping signal and the processing time of each stage provided by the present invention.

[0046] Figure 3This is a schematic structural diagram of a frequency hopping communication signal receiving device provided by the present invention. DETAILED DESCRIPTION

[0047] The drawings of the present invention are only for illustrative purposes and should not be construed as limiting the present invention. In order to better illustrate the following embodiments, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product; it is understandable to those skilled in the art that some well-known structures and their descriptions in the drawings may be omitted.

[0048] Example 1

[0049] In the prior art, the paper "Digital AGC Algorithm with Constant Envelope Waveform Based on FPGA" discloses the use of constant envelope communication waveform characteristics to independently calculate the signal energy of each sampling point, and adjust the receiving strength of the digital signal by truncation during the signal down-conversion process. This method processes the data at the back end of the digital filter so that the system has a certain anti-interference performance, but the use of truncation to adjust the data cannot make fine adjustments to the link data; and the patent "Ultra-short wave radio station automatic gain control circuit and control method" discloses the use of RF front-end signal analog signal detection and digital signal detection after analog-to-digital conversion to adjust the analog signal of the signal receiving path, achieving a receiving path dynamic range of up to 140dB, but in the The analog quantity at the front end of the RF signal as a judgment condition for AGC adjustment often reduces the system's anti-interference ability. At the same time, this method makes full use of the ADC receiving chip with a 60dB dynamic receiving range, and also requires the channel to have an 80dB receiving gain. Excessive channel receiving gain will deteriorate the signal-to-noise ratio of the received signal and reduce the system's receiving sensitivity. Secondly, the patent "A fully digital open-loop automatic gain control method and device for burst communication" discloses the use of fully digital signals to calculate the energy of the received burst signal so that the system has a certain anti-interference performance, but the system signal reception dynamic range is not described in detail, and its control convergence requires at least 20 sampling points, and the convergence time is relatively long, which makes it difficult to meet the signal reception requirements of the fast frequency hopping communication system.

[0050] This embodiment provides a method for receiving a frequency hopping communication signal. Figure 1 As shown, Figure 1 A schematic diagram of a flow chart of a method for receiving a frequency hopping communication signal provided in this embodiment, wherein the method comprises:

[0051] In step S1, the time domain characteristics of the frequency hopping communication signal obtained by continuously switching the receiving and transmitting frequencies of the transceiver are first divided into characteristic time periods, such as Figure 2 As shown, Figure 2 The frequency hopping signal and the processing time diagram of each stage provided in this embodiment are as follows: Figure 2It can be seen that the characteristic time periods obtained by the division include five characteristic time periods: T1, T2, T3, T4 and T5, wherein T1 represents the time for sending data at each frequency point, and T2 represents the switching frequency time. During this period, the frequency hopping control-related devices such as the frequency hopping filter and the mixer are mainly controlled, and the transmission and reception of the entire channel are in a blanking state; T3 represents the power rise time and AGC control time for receiving each hop data, T4 represents the time for calculating the digital gain adjustment, and T5 represents the time for calculating the target IQ sample number; wherein, (T3+T4) is the channel processing time for each hop signal. In the ultra-short wave frequency hopping communication waveform algorithm, this period of time is relatively short, and the design length is often less than 30 sample symbols. The time for different symbol rates is different, but it 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 (T3+T4).

[0052] Then, parameter configuration is performed for upper and lower thresholds, sample count value N1 in T3, sample count value N2 in T4, and digital gain adjustment count value; the upper and lower thresholds include RF comparison upper and lower thresholds and channel AGC upper and lower thresholds.

[0053] Preferably, in step S2, after completing the parameter configuration, the detector is used to continuously detect the energy of the RF signal, and when the detected energy is greater than the RF 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 RF comparison lower limit threshold of the threshold comparator, the received signal bypasses the overload protection attenuator;

[0054] Preferably, in the step S3, after the receiving frequency is switched, the average power of the channel receiving signal 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;

[0055] Since the average power calculation formula involves square and root calculations, and the square and root operations of the average power are not easy to implement in FPGA, occupy more resources and have a longer calculation cycle, the following steps are used to solve the above problem in the calculation within the T3 period of step S3:

[0056] Step S31: firstly, using standard equipment to calibrate the amplitude of I-channel signals outputted by the receiving device after the signals with different field strengths pass through the receiving device;

[0057] Step S32: Matlab software is then used to fit the relationship curve between field strength and signal strength, and the corresponding field strength values ​​of different signal amplitudes are stored 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, avoiding complex calculations.

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

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

[0060] Wherein, f(x) is the field strength, x is the average amplitude of the I-channel signal in the T3 period, and a, b, and c are the values ​​fitted using the test sample points.

[0061] Therefore, in this embodiment, the values ​​of a, b, and c are fitted using the test samples according to the fitting formula, and then the average amplitude x and the field strength f(x) are calculated with an accuracy of 0.25dBm according to the formula, and the corresponding f(x) value is stored in ROM0. Since the dynamic range of the entire system is -130dBm to 10dBm, the data storage length is 560, and the data volume is not large, which effectively reduces the complexity of the calculation and is easy to implement in engineering.

[0062] Preferably, in step S4, the received field strength value calculated in step S3 is compared with the channel AGC upper threshold value and the channel AGC lower threshold value respectively, and the attenuation value of the variable attenuator and the gain factor of the variable gain amplifier are adjusted accordingly according to the comparison results, so as to adjust the gain of the analog signal by using the received field strength;

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

[0064] When comparing the received field strength with the channel AGC lower limit threshold value, if the received field strength is less than the set channel AGC lower limit threshold value, adjust the variable attenuator to reduce the attenuation value. When adjusting the variable attenuator attenuation value still cannot meet the attenuation requirement, adjust the variable gain amplifier to increase the amplification factor; if the received field strength is greater than the set channel AGC lower limit threshold value, directly perform step S5.

[0065] This embodiment adjusts the relevant control parameters accordingly according to the comparison result between the received field strength and the channel AGC threshold value, thereby minimizing the influence of the out-of-band interference gain control and effectively improving the anti-interference capability of the receiver.

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

[0067] Specifically, in step S5, referring to the method in the T3 period, in the T4 period, the multiplication coefficient G of the amplitude values ​​of different signals corresponding to the target value is first calibrated, and then stored in ROM1 in a table lookup manner, and the amplitude value of the maximum sampling point of the signal is calculated during the signal reception process in the T4 period, so that each sample point is guaranteed to be undistorted in the adjustment of the digital gain, and then the adjusted multiplication coefficient G is directly read, and then multiplied with the input signal through a multiplier in the T5 period to obtain the target IQ sample number, thereby outputting stable IQ data. Among them, the multiplier is directly implemented using the IP core provided by the FPGA.

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

[0069] A0=G×A1

[0070] 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 in the T4 time period, and G is the gain coefficient.

[0071] The present invention uses a method of multiplying digital signals by coefficients to adjust the signal gain, rather than using a method of simply truncating the data to adjust the gain, so that the present invention has a higher gain adjustment accuracy and does not deteriorate the signal-to-noise ratio of the received data.

[0072] Example 2

[0073] This embodiment provides a frequency hopping communication signal receiving device, such as Figure 3 As shown, Figure 3 A schematic diagram of the structure of the frequency-hopping communication signal receiving device provided in this embodiment. As can be seen from the figure, the device includes a channel control unit and a baseband processing unit; wherein the channel control unit is mainly implemented by a hardware circuit, and the baseband processing unit is mainly implemented by a digital signal processing chip such as an 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 digitally controlled attenuator;

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

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

[0077] The channel control unit also includes a detector, a threshold comparator and a DAC converter;

[0078] The detector is arranged between the frequency hopping filter and the overload protection attenuator. Before the signal enters the overload protection attenuator, it needs to be detected by the detector to prevent the device circuit from being damaged due to excessive signal input.

[0079] The threshold comparator is connected between the detector and the overload protection attenuator, and is used to compare the energy of the signal. The overload protection attenuator then receives the comparison result and makes corresponding parameter adjustments. When the received signal is at its strongest, the receiver received signal strength is around 10dBm. Therefore, the threshold value of the threshold comparator is set to 10dBm±1dBm, that is, its range is 9dBm to 11dBm.

[0080] The DAC converter is connected to the burst signal receiving controller and the variable gain amplifier in the baseband processing unit, and is used to receive control parameters and convert the input digital signal into a corresponding analog signal, and then adjust the parameters through the variable gain amplifier and the digitally controlled attenuator; the variable gain amplifier is a voltage-controlled low-noise amplifier, and the maximum gain value is 50dBm, that is, the gain value of the entire channel is 50dBm; the maximum attenuation value of the digitally controlled attenuator is 60dBm, and the control accuracy is 0.25dBm;

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

[0082] The signal then enters the DDC digital down-converter and digital filter in turn for down-conversion and digital filtering, and then enters the corresponding calculator to calculate the maximum sample point amplitude value and digital gain adjustment. Finally, the obtained gain adjustment value is input into the digital gain adjuster for gain adjustment, and finally the stable IQ data is input.

[0083] In the receiving device provided in the present application, the channel control unit is first 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, fully utilizing the dynamic range of the ADC chip, and then amplifying the digital signal after analog-to-digital conversion to reduce the channel gain and the noise coefficient. All control bases of the received signal come from the data at the back end of the digital filter, which effectively prevents the gain error control caused by adjacent channel interference and improves the anti-interference ability of the receiver.

[0084] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the technical solution of the present invention, and are not intended to limit the specific implementation methods of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the claims of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A method for receiving a frequency hopping communication signal, characterized in that: The method comprises: S1: The time domain characteristics of the frequency hopping communication signal obtained by continuously switching the receiving and transmitting frequencies of the transceiver are divided into five characteristic time periods, namely, T1, T2, T3, T4, and T5, wherein T1 represents the time for sending data at each frequency point, T2 represents the switching frequency time, T3 represents the power rise time and AGC control time for receiving each hop data, T4 represents the time for calculating the digital gain adjustment, and T5 represents the time for calculating the target IQ sample number; then, parameter configuration is performed, and the upper and lower limit thresholds, the sample count value N1 in T3, the sample count value N2 in T4, and the digital gain adjustment count value are configured; 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 according to 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 result, so as to adjust 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 calculate the digital gain adjustment value, then look up the table to read the multiplication coefficient G, 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 receiving signal in the T3 time period according to the set sample count value N1 of the T3 time period, and calculating the channel receiving field strength according to the average power includes: S31: using standard equipment to calibrate the amplitude of the I-channel signal output after the signals of different field strengths 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 method for receiving a frequency hopping communication signal 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: f(x)=ax b +c Wherein, f(x) is the field strength, x is the average amplitude of the I-channel signal in the T3 period, and a, b, and c are the values ​​fitted using the test sample points.

4. A method for receiving a frequency hopping communication signal according to claim 3, characterized in that: The step S4 includes: When the receiving field strength is compared with the upper limit threshold value, if the receiving field strength is greater than the set upper limit threshold value, the variable gain amplifier amplification factor is reduced. When the reduced amplification factor still cannot meet the receiving attenuation requirement, the variable attenuator is adjusted to increase the attenuation value; if the receiving field strength is less than the set upper limit 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: The step S5 specifically includes: calibrating the multiplication coefficient G of the target value corresponding to the amplitude value of different signals, and storing it in ROM1 in a table lookup manner, directly reading the adjusted multiplication coefficient G after calculating the amplitude value of the maximum sampling point of the signal during the signal reception process in the T4 time period, and then multiplying it with the input signal through a multiplier in the T5 time period to obtain the target IQ sample point number, thereby outputting stable IQ data.

6. A method for receiving a frequency hopping communication signal according to claim 5, characterized in that: The step S5 also includes fitting a relationship curve between the target amplitude value and the multiplication coefficient using matlab software, and the fitting formula corresponding to the fitted relationship curve is: A0=G×A1 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 in the T4 time period, and G is the multiplication coefficient.

7. A frequency hopping communication signal receiving device, characterized in that: 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, 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.

8. A 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, and its maximum gain is 50dBm.

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

10. A 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 to -20dBm.

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