阅读说明：本技术 一种基于突发信号的接收增益控制方法及系统 (Receiving gain control method and system based on burst signal ) 是由 朱庆浩 吴博 杨林刚 于 2021-07-29 设计创作，主要内容包括：本发明提出了一种基于突发信号的接收增益控制方法及系统,所述方法包括：初始化信号处理装置的工作参数；接收突发信号,并通过混频滤波转变为基带信号；将基带信号按不同增益值进行放大后,输出至模数转换器,转化为新的基带信号；新的基带信号通过解调输出译码结果；通过对译码结果的判断,选择并输出最终的译码结果。对于同一段突发信号,分别通过不同增益的中频放大器和ADC后,进入解调模块解调和译码,在数据选择模块比较译码结果,选择正确的译码结果输出。还给出了模拟中频放大器的增益值如何选取的方法。在整体方法的实现过程中,每个模拟中频放大器的增益都是固定的,并不依赖于先前正常的突发信号的增益值。(The invention provides a receiving gain control method and a system based on burst signals, wherein the method comprises the following steps: initializing working parameters of the signal processing device; receiving a burst signal, and converting the burst signal into a baseband signal through frequency mixing filtering; amplifying the baseband signals according to different gain values, outputting the amplified baseband signals to an analog-to-digital converter, and converting the amplified baseband signals into new baseband signals; the new baseband signal outputs a decoding result through demodulation; and selecting and outputting a final decoding result by judging the decoding result. For the same section of burst signals, the burst signals respectively pass through the intermediate frequency amplifier and the ADC with different gains, then enter the demodulation module for demodulation and decoding, the data selection module compares decoding results, and selects correct decoding results to output. A method of how to select the gain value of the analog if amplifier is also presented. In the implementation of the overall method, the gain of each analog if amplifier is fixed and does not depend on the gain value of the previous normal burst signal.)

1. A receiving gain control method based on burst signals is characterized by comprising the following steps:

step 1, initializing working parameters of a signal processing device; the signal processing apparatus includes: the device comprises a radio frequency receiving module, a mixing filtering module, an analog intermediate frequency amplifier, an analog-to-digital converter, a demodulation module and a data selection module;

step 2, receiving the burst signal, and converting the burst signal into a baseband signal through frequency mixing filtering;

step 3, amplifying the baseband signals according to different gain values, outputting the amplified baseband signals to an analog-to-digital converter, and converting the amplified baseband signals into new baseband signals;

step 4, the new baseband signal outputs a decoding result through demodulation;

and 5, selecting and outputting a final decoding result through judging the decoding result.

2. The burst signal based reception gain control method according to claim 1,

step 1, when initializing the working parameters of the signal processing device, specifically comprising the following steps:

step 1.1, determining the input level range of an analog-digital converter;

step 1.2, determining the level range of radio frequency output;

and step 1.3, determining the gain value of the analog intermediate frequency amplifier.

3. The burst signal based reception gain control method according to claim 2,

step 1.1 when determining the input level range of the analog-to-digital converter, first determine the input level range that the demodulation module can demodulate correctly, i.e. determine the amplitude range [ AM ] of the analog signal input by the analog-to-digital converter_min，AM_max]And the range is used as the basis for determining the gain value of the analog intermediate frequency amplifier;

first, the gain value of the analog intermediate frequency amplifier is set to the minimum value g of the amplifier_min(ii) a Secondly, the radio frequency outputs analog modulation signals with different levels, and the output level range [ In ] of the modulation signals is determined when the demodulation module can decode normally_min，In_max]If the demodulation module is correctly demodulating, i.e. the error rate is 0, the ADC input level range is [ In ]_min+g_min，In_max+g_min]。

4. The burst signal based reception gain control method according to claim 2,

step 1.2, when determining the level range of the radio frequency output, on the premise of meeting the range of the ADC input level in step 1.1, determining the signal level range of the radio frequency output end according to different gain values;

in the linear gain interval of the analog intermediate frequency amplifier, the signal point-flat range of the radio frequency output end can be used in RF_min，RF_max]And when the gain interval is not linear, finding out the corresponding interval range according to actual measurement.

5. The burst signal based reception gain control method according to claim 2,

step 1.3, when determining the gain value of the analog intermediate frequency amplifier, determining the number of channels of the analog intermediate frequency amplifier and the ADC and the corresponding gain value in data transmission according to the level range of radio frequency output in practical application;

and (3) determining corresponding radio frequency output level ranges with different gain values according to the step 1.2, wherein the radio frequency output level ranges in practical application are determined by the design indexes of a modem, so that the number of required channels of the analog intermediate frequency amplifier and the ADC is determined.

6. The burst signal based reception gain control method according to claim 5,

the principle of selecting the number of the channels of the analog intermediate frequency amplifier and the ADC is as follows: selecting a channel number less than the expected number on the premise of ensuring the output level range corresponding to the gain value and covering the radio frequency output level range in practical application; after selection, the corresponding gain value of the analog intermediate frequency amplifier is correspondingly stored in the data processing module.

7. The burst signal based reception gain control method according to claim 1,

when the new baseband signal outputs a decoding result through demodulation and has an error, selecting and outputting a final decoding result through the judgment of the decoding result; when the correct decoding data is selected to be output, according to the number of the channels of the analog intermediate frequency amplifier and the ADC determined in step 1.3 and the number of the demodulation modules in the data processing module, when the burst signal is amplified by the intermediate frequency amplifiers with different gains, the burst signal is converted into a digital baseband signal, and the digital baseband signal is transmitted to the corresponding demodulation module, and then the output decoding data is selected.

8. The burst signal based reception gain control method according to claim 7,

the process of selecting the final decoding result is: when a plurality of demodulators capture frame headers of burst signals, adding 1 to the capture count of each demodulator, and when decoding data is output, adding 1 to each decoding count, and respectively calculating the difference value between the capture count and the decoding count of a demodulation module; if the current decoding data is the result decoded by the same burst signal, then judging whether the decoding result is correct or not; when the decoding result is error, directly discarding the error data; otherwise, the correct group of data is selected for reception and output as final data.

9. A receiving gain control system based on burst signals is characterized by comprising:

a radio frequency receiving module configured to receive the burst signal and transmit the burst signal to the mixing filter module;

the frequency mixing filtering module is used for receiving the burst signal output by the radio frequency receiving module, converting the burst signal into a baseband signal and inputting the baseband signal into the analog intermediate frequency amplifier;

the analog intermediate frequency amplifier is arranged for receiving the baseband signal output by the mixing filter module and amplifying the baseband signal according to different gain values;

an analog-to-digital converter arranged to receive the baseband signal amplified by the analog intermediate frequency amplifier and convert it into a discrete baseband signal;

the demodulation module is arranged for demodulating the baseband signal output by the analog-to-digital converter and outputting a corresponding decoding result;

and the data selection module is arranged for receiving the decoding result output by the demodulation module, judging different decoding data and selecting the final correct decoding result to output.

10. The burst signal based reception gain control system according to claim 9,

the output end of the radio frequency receiving module is connected with the input end of the frequency mixing filtering module;

the frequency mixing filter module simultaneously outputs the signals to at least one analog intermediate frequency amplifier, the analog intermediate frequency amplifier amplifies received signals according to different gain values, then the amplified signals are output to the analog-to-digital converter to be converted into baseband signals, and the baseband signals enter the data processing module; the data processing module is composed of a demodulation module and a data selection module, wherein the demodulation module demodulates and outputs a decoding result, and the data processing module judges decoding data, selects and outputs a final decoding result.

Technical Field

The invention relates to a receiving gain control method and a receiving gain control system based on burst signals, in particular to the technical field of satellite communication.

Background

Burst signals are widely used in satellite communication systems, especially in TDMA communication mode, and there may be great difference in signal transmission power among different terrestrial stations of burst signals in different time slots, which results in that the gain of the receiving end must be adjusted to adapt to the input of different input signals and to eliminate the interference of noise.

The existing automatic gain control mode is complex, gain adjustment is required according to a burst or an initial value received correctly at the previous time, a gain amplifier is controlled in real time, or iteration is carried out for multiple times until a burst signal is captured, and correct demodulation of each burst cannot be guaranteed.

Disclosure of Invention

The purpose of the invention is as follows: a method and system for controlling the receiving gain based on burst signals are provided to solve the above problems in the prior art.

The technical scheme is as follows: in a first aspect, a method for controlling a receive gain based on a burst signal is provided, where the method specifically includes the following steps:

step 1, initializing working parameters of a signal processing device; the signal processing apparatus includes: the device comprises a radio frequency receiving module, a mixing filtering module, an analog intermediate frequency amplifier, an analog-to-digital converter, a demodulation module and a data selection module;

step 2, receiving the burst signal, and converting the burst signal into a baseband signal through frequency mixing filtering;

step 3, amplifying the baseband signals according to different gain values, outputting the amplified baseband signals to an analog-to-digital converter, and converting the amplified baseband signals into new baseband signals;

step 4, the new baseband signal outputs a decoding result through demodulation;

and 5, selecting and outputting a final decoding result through judging the decoding result.

In some implementations of the first aspect, initializing an operating parameter of the signal processing apparatus includes:

step 1.1, determining the input level range of an analog-digital converter;

step 1.2, determining the level range of radio frequency output;

and step 1.3, determining the gain value of the analog intermediate frequency amplifier.

Specifically, in step 1.1, when determining the input level range of the analog-to-digital converter, first, the input level range that the demodulation module can correctly demodulate is determined, that is, the amplitude range [ AM ] of the analog signal input by the analog-to-digital converter is determined_min，AM_max]And the range is used as a basis for determining the gain value of the analog intermediate frequency amplifier. First, the gain value of the analog intermediate frequency amplifier is set to the minimum value g of the amplifier_min(ii) a Secondly, the radio frequency outputs analog modulation signals with different levels, and the output level range [ In ] of the modulation signals is determined when the demodulation module can decode normally_min，，In_max]When the demodulation module is correctly demodulating, i.e. the error rate is 0, the ADC input level range is [ In ]_min+g_min，In_max+g_min]。

Step 1.2, when determining the level range of the radio frequency output, determining the level range of the radio frequency output when different gains of the analog intermediate frequency amplifier are required, that is, on the premise of meeting the range of the ADC input level in step 1.1, determining the signal level range of the radio frequency output end according to different gain values. Specifically, in the linear gain section of the analog intermediate frequency amplifier, the signal point-flat range of the radio frequency output end can be used in RF_min，RF_max]The non-linear gain interval is represented by a corresponding interval range which needs to be measured.

Step 1.3, when determining the gain value of the analog intermediate frequency amplifier, the number of channels of the analog intermediate frequency amplifier and the ADC in data transmission and the corresponding gain value are determined according to the level range of the radio frequency output in practical application. Specifically, the radio frequency output level range corresponding to different gain values is determined in step 1.2, and the radio frequency output level range in practical application is determined by the design index of the modem, so that the number of channels of the analog intermediate frequency amplifier and the ADC required can be determined, and the selection principle is as follows: on the premise of ensuring the output level range corresponding to the gain value and covering the radio frequency output level range in practical application, the number of selected channels is as small as possible. After selection, the corresponding gain value of the analog intermediate frequency amplifier is correspondingly stored in the data processing module.

In some implementations of the first aspect, since the output levels of the burst signals are the same, but the levels of the ADC outputs are different, some channels of ADC samples are saturated, the baseband signals are distorted, and decoding is erroneous; some channels have insufficient gain, the frame header of the burst signal cannot be detected, and demodulation is not performed, so that the decoded data needs to be judged, and finally correct decoded data is selected to be output. When selecting correct decoding data to output, the following steps are specifically performed: since the number of channels of the analog intermediate frequency amplifier and the ADC is determined in step 1.3, and the number of demodulation modules in the data processing module is also determined, when the burst signal is amplified by the intermediate frequency amplifiers with different gains, the burst signal is converted into a digital baseband signal, and the digital baseband signal is transmitted to the corresponding demodulation module, and then the output decoded data is selected.

Specifically, when the plurality of demodulators capture the frame headers of the burst signals, the capture count of each demodulator is incremented by 1, and when the decoded data is output, the decoding count of each demodulator is incremented by 1, and the difference between the capture count and the decoding count of the demodulation module is calculated respectively. If the current decoding data is the result decoded by the same burst signal, then the correctness of the decoding result is judged. If the judgment result is wrong, the data with wrong decoding is directly discarded, and the remaining data with correct decoding is selected to be received as a group of finally output data.

In a second aspect, a burst signal-based reception gain control system is provided, where the system specifically includes:

a radio frequency receiving module configured to receive the burst signal and transmit the burst signal to the mixing filter module;

the frequency mixing filtering module is used for receiving the burst signal output by the radio frequency receiving module, converting the burst signal into a baseband signal and inputting the baseband signal into the analog intermediate frequency amplifier;

the analog intermediate frequency amplifier is arranged for receiving the baseband signal output by the mixing filter module and amplifying the baseband signal according to different gain values;

an analog-to-digital converter arranged to receive the baseband signal amplified by the analog intermediate frequency amplifier and convert it into a discrete baseband signal;

the demodulation module is arranged for demodulating the baseband signal output by the analog-to-digital converter and outputting a corresponding decoding result;

and the data selection module is arranged for receiving the decoding result output by the demodulation module, judging different decoding data and selecting the final correct decoding result to output.

In some realizations of the second aspect, the output end of the radio frequency receiving module is connected with the input end of the mixing filtering module; the frequency mixing filtering module simultaneously outputs the signals to at least one analog intermediate frequency amplifier, the analog intermediate frequency amplifier amplifies the received signals according to different gain values, the amplified signals are output to an analog-to-digital converter and converted into baseband signals, and the baseband signals enter a data processing module; the data processing module is composed of a demodulation module and a data selection module, wherein the demodulation module demodulates and outputs a decoding result, and the data processing module judges decoding data, selects and outputs a final decoding result.

Has the advantages that: the invention provides a burst signal-based receiving gain control method and a burst signal-based receiving gain control system. The invention also provides a method for selecting the gain value of the analog intermediate frequency amplifier. In the implementation of the overall method, the gain of each analog if amplifier is fixed, i.e. its gain value is independent of the level value of the burst signal during communication and does not depend on the gain value of the previous normal burst signal. In addition, due to the existence of multiple channels, on the premise of meeting the demodulation threshold, a gain value-based selection mechanism always exists in a certain channel, so that the frame header can be captured and correctly decoded, and correct demodulation and decoding output of each section of burst signal are ensured.

Drawings

Fig. 1 is a schematic diagram of a receiving end model according to an embodiment of the present invention.

FIG. 2 is a block diagram of method steps for an embodiment of the present invention.

FIG. 3 is a flow chart of a data selection process according to an embodiment of the invention.

Detailed Description

In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without one or more of these specific details. In other instances, well-known features have not been described in order to avoid obscuring the invention.

In one embodiment, a method for controlling a receiving gain based on a burst signal is provided, which specifically includes the following steps:

step 1, initializing working parameters of a signal processing device; the signal processing apparatus includes: the device comprises a radio frequency receiving module, a mixing filtering module, an analog intermediate frequency amplifier, an analog-to-digital converter, a demodulation module and a data selection module;

step 2, receiving the burst signal, and converting the burst signal into a baseband signal through frequency mixing filtering;

step 3, amplifying the baseband signals according to different gain values, outputting the amplified baseband signals to an analog-to-digital converter, and converting the amplified baseband signals into new baseband signals;

step 4, the new baseband signal outputs a decoding result through demodulation;

and 5, selecting and outputting a final decoding result through judging the decoding result.

Specifically, as shown in fig. 1, a signal received by the radio frequency receiving module is converted into a baseband signal after passing through the frequency mixing filtering module, the baseband signal is simultaneously output to two analog intermediate frequency amplifiers, the intermediate frequency amplifiers amplify the received signal according to different gain values, and then output to an analog-to-digital converter (ADC) to be converted into a baseband signal, and the baseband signal enters the data processing module. The data processing module consists of a demodulation module and a data selection module. The demodulation module demodulates and outputs a decoding result, and the data processing module judges two paths of decoding data and outputs a final decoding result.

In a further embodiment, initializing the operating parameters of the signal processing device comprises the steps of:

and 1.1, determining the input level range of the analog-digital converter.

Specifically, when determining the input level range of the analog-to-digital converter, first, the input level range in which the demodulation module maintains the bit error rate to be 0, that is, the input level range of the corresponding ADC, is determined. When the maximum amplitude of the burst signal exceeds the maximum input level of the ADC after passing through the gain of the analog if amplifier, the digital signal converted by the ADC at the exceeding part is distortion, and the distortion reaches a certain program, which may cause the decoding failure of the demodulation module; if the input level of the ADC is too low, the demodulation module cannot capture the frame header, and the current burst data is lost. In summary, the range interval [ AM ] of the ADC input level is obtained_min，AM_max]In particular, the gain value of the analog intermediate frequency amplifier is set to a nominal minimum gain value.

And step 1.2, determining the level range of the radio frequency output.

Specifically, on the premise of satisfying the range of the ADC input level in step 1.1, the signal level range of the rf output terminal is determined according to different gain values. In the linear gain interval of the analog intermediate frequency amplifier, the signal point-flat range of the radio frequency output end can be used in RF_min，RF_max]The non-linear gain interval is represented by a corresponding interval range which needs to be measured.

And step 1.3, determining the gain value of the analog intermediate frequency amplifier.

Specifically, the number of channels of the analog intermediate frequency amplifier and the ADC in data transmission and the corresponding gain value are determined according to the level range of the radio frequency output in practical application. Typically, the level range is related to the symbol rate of the burst signal.

According to step 1.2, we determine the corresponding radio frequency output level range at different gain values. The range of rf output levels in practical applications is determined by the design specifications of the modem. Therefore, the number of required channels of the analog intermediate frequency amplifier and the ADC can be determined, and the selection principle should be: on the premise of ensuring that the output level range corresponding to the gain value should cover the radio frequency output level range in practical application, the number of selected channels is as small as possible. The union of the input level ranges for each channel should cover the input level range of the actual application and the intersection is not empty. After selection, the corresponding gain value of the analog intermediate frequency amplifier is correspondingly stored in the data processing module.

In a further embodiment, the number of channels of the analog if amplifier and ADC is determined in step 1.3, as well as the number of demodulation modules within the data processing module. When the burst signal is amplified by the intermediate frequency amplifiers with different gains, the burst signal is converted into a digital baseband signal and is transmitted to the corresponding demodulation module. The output levels of the burst signals are the same, but the levels output by the ADC are different, and in some channels, the ADC is saturated in sampling, baseband signals are distorted, and decoding is wrong; some channels have insufficient gain, the frame header of the burst signal cannot be detected, and demodulation is not performed. Therefore, the decoded data needs to be judged, and finally, correct decoded data is selected for output.

When a plurality of demodulators capture the frame header of a burst signal, the capture count { Trap1, Trap2, … …, Trap, n is the number of channels } of each demodulator is added with 1, and when decoded data is output, the decode count { Deco 1, Deco 2, … …, Decon, n is the number of channels } is added with 1, and the difference between the capture count and the decode count of a demodulation module is calculated as Trap-Decon. When | deta1| ═ deta2| ═ detan |, it indicates that the current decoded data is the result decoded from the same burst. And then judging whether the decoding result is correct or not, directly discarding the data with wrong decoding, and selecting a group of the remaining data with correct decoding for receiving as final output data.

In the preferred embodiment, first, let the symbol rate R of the burst signal_s2048kbps, with a desired input level range of [ -67dBm, -27dBm]And thus determines the level range of the burst signal output by the rf receiving module. Secondly, the mixing filtering, analog intermediate frequency amplifier, ADC and demodulation modules adopt corresponding modules of the BWC200A modem.

The linear gain range of the analog intermediate frequency amplifier of the BWC200A modem is [15, 76], and the step is 0.25 dB. The gain value is fixed to the minimum value of 15dB, the level value of the burst signal is changed, the level interval of the burst signal under the condition of no error code and no loss in demodulation is obtained, and the result is [ -46.16dBm, -22.02dBm ]. Then the input level at the ADC input is-31.16 dBm-7.02 dBm, with a maximum to minimum difference of 24.14 dB.

Since the full gain of the analog if amplifier is linear, the rf output level ranges from-31.16-g for different gain values gn_n，-7.02-g_n]。

According to the input level range of the expected radio frequency output [ -67dBm, -27dBm ], the number of receiving channels spanning 40dB is selected to be N-ceil (40/24.14) ═ 2. The union of the input level ranges corresponding to each channel should cover the expected input level range, and an intersection should be used to make up for errors in the test. Following this principle, the first channel was chosen to have a gain value of 17, corresponding to an input level range of [ -48.16dBm, -24.02dBm ], and the second channel was chosen to have a gain value of 39, for an input level range of [ -70.16dBm, -46.02dBm ]. The union of the input level ranges of the two channels is [ -70.16dBm, -24.02dBm ], which contains the expected input level range, and the intersection of the two is [ -48.16dBm, -46.02dBm ], and the intersection of 2dB ensures that the phenomenon that the two channels cannot be correctly demodulated when the burst signal is temporary due to the error existing in the test can not be caused.

And finally, selecting correct decoding data to output. The existence of two receiving channels can decode and output two groups of data at most. It is necessary to choose from which to choose the correct set of data for the resulting output.

As shown in fig. 3, when the frame header of the burst is captured, the corresponding capture count Trapn +1, n is 1, 2, and the value is reserved, and when the data selection module receives the decoded data, the decode count Decodn +1, n is 1, 2 of the corresponding channel.

If the values of deta1 ═ Trap1-Decod1|, and deta2 ═ Trap2-Decod2| are compared, the decoded data is the result of demodulating and decoding the same burst signal. And then judging the flag bit of the decoding result, if the flag bit is 1, indicating correct decoding, and if the flag bit is 0, indicating decoding error, and discarding the current data. When the phenomenon that both channels decode correctly exists, the data decoded by the channel 1 is directly output as a final result.

In one embodiment, a burst signal based reception gain control system is provided, which specifically includes:

a radio frequency receiving module configured to receive the burst signal and transmit the burst signal to the mixing filter module;

the frequency mixing filtering module is used for receiving the burst signal output by the radio frequency receiving module, converting the burst signal into a baseband signal and inputting the baseband signal into the analog intermediate frequency amplifier;

the analog intermediate frequency amplifier is arranged for receiving the baseband signal output by the mixing filter module and amplifying the baseband signal according to different gain values;

an analog-to-digital converter arranged to receive the baseband signal amplified by the analog intermediate frequency amplifier and convert it into a discrete baseband signal;

the demodulation module is arranged for demodulating the baseband signal output by the analog-to-digital converter and outputting a corresponding decoding result;

and the data selection module is arranged for receiving the decoding result output by the demodulation module, judging different decoding data and selecting the final correct decoding result to output.

In a further embodiment, the output end of the radio frequency receiving module is connected with the input end of the mixing filtering module; the frequency mixing filtering module simultaneously outputs the signals to at least one analog intermediate frequency amplifier, the analog intermediate frequency amplifier amplifies the received signals according to different gain values, the amplified signals are output to an analog-to-digital converter and converted into baseband signals, and the baseband signals enter a data processing module; the data processing module is composed of a demodulation module and a data selection module, wherein the demodulation module demodulates and outputs a decoding result, and the data processing module judges decoding data, selects and outputs a final decoding result.

In the invention, the same section of burst signals respectively pass through the intermediate frequency amplifier and the ADC with different gains and then enter the demodulation module for demodulation and decoding, the decoding result is compared in the data selection module, and the correct decoding result is selected and output. The invention also provides a method for selecting the gain value of the analog intermediate frequency amplifier. In the implementation of the overall method, the gain of each analog if amplifier is fixed, i.e. its gain value is independent of the level value of the burst signal during communication and does not depend on the gain value of the previous normal burst signal. In addition, due to the existence of multiple channels, on the premise of meeting the demodulation threshold, a gain value-based selection mechanism always exists in a certain channel, so that the frame header can be captured and correctly decoded, and correct demodulation and decoding output of each section of burst signal are ensured.

As noted above, while the present invention has been shown and described with reference to certain preferred embodiments, it is not to be construed as limited thereto. Various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.