Self-adaptive demodulation circuit and method

Abstract

The invention discloses a self-adaptive demodulation circuit and a self-adaptive demodulation method. The adaptive demodulation circuit comprises a signal input module used for receiving a first signal and demodulating the first signal into a second signal; the first signal comprises a carrier with signaling modulation; the second signal comprises a baseband envelope signal; the power detection module is connected with the signal input module, and the power detection module generates a first control signal and a second control signal according to the power of the second signal when receiving the detection signal; the adjusting module is connected with the signal input module and the power detection module, and filters and outputs the second signal according to the first control signal; or outputting the second signal according to the second control signal; the signal demodulation module is connected with the adjusting module and the power detection module, and demodulates and outputs the second signal according to the first control signal or the second control signal; the speed at which the second signal is demodulated according to the second control signal is faster than the speed at which the second signal is demodulated according to the first control signal. The method has a good signal demodulation effect.

Description

Technical Field

[0001] The present invention relates to the technical field of demodulation circuits, and in particular to an adaptive demodulation circuit and method. Background Art

[0002] As people's environmental awareness gradually increases, passive Internet of Things technology has gradually become an important part of the communication system. The communication of passive Internet of Things has high requirements on the signal coverage range of the base station. Since the antenna needs to be directly connected to the base station, the power of the signal received by the antenna at different distances from the base station will also be greatly different, so that the demodulation circuit may not be able to correctly demodulate the signal received by the antenna, resulting in poor signal demodulation effect. Summary of the invention

[0003] The invention provides an adaptive demodulation circuit and method to improve the signal demodulation effect.

[0004] According to one aspect of the present invention, there is provided an adaptive demodulation circuit, comprising:

[0005] A signal input module, used for receiving a first signal and demodulating it into a second signal; wherein the first signal includes: a carrier with signaling modulation; the second signal includes: a baseband envelope signal;

[0006] A power detection module, the power detection module is connected to the signal input module, and the power detection module is used to generate a first control signal and a second control signal according to the power of the second signal when receiving the detection signal;

[0007] an adjustment module connected to the signal input module and the power detection module, the adjustment module being used to filter and output the second signal according to the first control signal; or to output the second signal according to the second control signal;

[0008] A signal demodulation module is connected to the adjustment module and the power detection module, and the signal demodulation module is used to demodulate and output the second signal according to the first control signal or the second control signal; wherein, a speed of demodulating the second signal according to the second control signal is faster than a speed of demodulating the second signal according to the first control signal.

[0009] Optionally, the signal input module includes:

[0010] An antenna, used to receive the first signal sent by the base station;

[0011] A negative envelope detector is connected to the antenna, and is used to demodulate the first signal into the second signal; the power of the second signal is inversely proportional to the power of the first signal.

[0012] Optionally, the power detection module includes:

[0013] a first comparator, wherein a first input end of the first comparator is used to access a reference power, and a second input end of the first comparator is connected to the signal input module; the first comparator is used to generate the first control signal according to the reference power and the power of the second signal;

[0014] A trigger, wherein the input end of the trigger is connected to the output end of the first comparator, the control end of the trigger is used to receive the detection signal and turn on the trigger according to the detection signal; the output end of the trigger is connected to the adjustment module and the signal demodulation module; the trigger is used to output the first control signal when turned on;

[0015] An inverter, wherein the input end of the inverter is connected to the output end of the trigger, and the output end of the inverter is connected to the regulation module and the signal demodulation module; the inverter is used to invert the first control signal into the second control signal and output it.

[0016] Optionally, the adjustment module includes:

[0017] a first capacitor and a first switch, wherein a first end of the first switch is connected to the signal input module, a second end of the first switch is connected to a first end of the first capacitor, a second end of the first capacitor is connected to a ground terminal, a control end of the first switch is connected to the power detection module, and the first switch is used to be turned on or off according to the first control signal;

[0018] A second capacitor and a second switch, wherein the first end of the second switch is connected to the signal input module, the second end of the second switch is connected to the first end of the second capacitor, the second end of the second capacitor is connected to the ground end, the control end of the second switch is connected to the power detection module, and the second switch is used to turn on or off according to the second control signal; wherein the capacity of the first capacitor is greater than the capacity of the second capacitor.

[0019] Optionally, the signal demodulation module includes:

[0020] A second comparator, wherein a first input terminal of the second comparator is connected to the regulating module;

[0021] a third capacitor and a third switch, wherein a first end of the third switch is connected to the second input end of the second comparator, a first end of the third switch is also connected to the regulating module, a second end of the third switch is connected to the first end of the third capacitor, a second end of the third capacitor is connected to the ground end, a control end of the third switch is connected to the power detection module, and the third switch is used to be turned on or off according to the first control signal;

[0022] a fourth capacitor and a fourth switch, wherein a first end of the fourth switch is connected to the second input end of the second comparator, a first end of the fourth switch is also connected to the regulating module, a second end of the fourth switch is connected to the first end of the fourth capacitor, a second end of the fourth capacitor is connected to the ground end, a fourth switch control end is connected to the power detection module, and the fourth switch is used to turn on or off according to the second control signal; wherein the capacity of the third capacitor is greater than that of the fourth capacitor, the third capacitor and the fourth capacitor are used to generate a power average value of the second signal, and the generation time of the power average value is positively correlated with the capacity;

[0023] The second comparator is used for demodulating and outputting the second signal according to the power of the second signal and the power average value of the second signal.

[0024] Optionally, the signal demodulation module further includes:

[0025] A first resistor, wherein a first end of the first resistor is connected to the regulating module, a second end of the first resistor is connected to the second input end of the second comparator, and the first resistor is used for filtering.

[0026] Optionally, the adaptive demodulation circuit further includes:

[0027] An amplification module is connected between the adjustment module and the signal demodulation module, and is used to amplify the second signal.

[0028] Optionally, the adaptive demodulation circuit further includes: a digital baseband module, connected to the power detection module, configured to receive downlink signaling sent by a base station and generate the detection signal.

[0029] According to another aspect of the present invention, an adaptive demodulation method is provided, which is applied to the adaptive demodulation circuit according to any embodiment of the present invention; the adaptive demodulation method comprises:

[0030] Receive a first signal through a signal input module and demodulate the first signal into a second signal; wherein the first signal includes: a carrier with signaling modulation; the second signal includes: a baseband envelope signal;

[0031] When the power detection module receives the detection signal, the power detection module generates a first control signal and a second control signal according to the power of the second signal; and outputs the first control signal to the adjustment module and the signal demodulation module, and outputs the second control signal to the adjustment module and the signal demodulation module;

[0032] The regulating module filters the second signal according to the first control signal and outputs the second signal to the signal demodulation module / or outputs the second signal to the signal demodulation module according to the second control signal;

[0033] The signal demodulation module demodulates and outputs the second signal according to the first control signal or the second control signal; wherein a speed of demodulating the second signal according to the second control signal is faster than a speed of demodulating the second signal according to the first control signal.

[0034] Optionally, the regulating module filters the second signal according to the first control signal and outputs it to the signal demodulation module / or outputs the second signal to the signal demodulation module according to the second control signal, including:

[0035] The first control signal controls the first switch to be turned on, and the second signal is output to the signal demodulation module after being filtered by the first capacitor;

[0036] The second control signal controls the second switch to be turned on, and the second signal is output to the signal demodulation module via the second capacitor:

[0037] The signal demodulation module demodulates and outputs the second signal according to the first control signal or the second control signal, including:

[0038] The first control signal controls the third switch to be turned on, the third capacitor generates a power average value of the second signal, and the second comparator demodulates and outputs the second signal according to the power of the second signal and the power average value of the second signal;

[0039] The second control signal controls the fourth switch to be turned on, the fourth capacitor generates an average power value of the second signal, and the second comparator demodulates and outputs the second signal according to the power of the second signal and the average power value of the second signal.

[0040] The technical solution provided in the embodiment of the present invention realizes power detection of the first signal and the second signal by setting a power detection module, and generates different first control signals and second control signals according to different power sizes. The adjustment module can also perform adaptive filtering or lossless output of the second signal according to the first control signal or the second control signal. And demodulate and output through the signal demodulation module. The present invention can perform adaptive demodulation and output for first signals of different powers, improve the accuracy of demodulation data when the power of the first signal is low, and improve the rapidity of demodulation when the power of the first signal is high, and has a better demodulation effect.

[0041] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0043] Figure 1 is a schematic structural diagram of an adaptive demodulation circuit provided according to an embodiment of the present invention;

[0044] Figure 2 is a schematic structural diagram of another adaptive demodulation circuit provided according to an embodiment of the present invention;

[0045] Figure 3 is a flow chart of an adaptive demodulation method provided according to an embodiment of the present invention;

[0046] Figure 4 is a flowchart of a specific implementation method of S130 provided according to an embodiment of the present invention;

[0047] Figure 5 It is a flowchart of a specific implementation method of S140 provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0048] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0049] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0050] An embodiment of the present invention provides an adaptive demodulation circuit. Figure 1 A schematic diagram of the structure of an adaptive demodulation circuit provided by an embodiment of the present invention. Figure 1 , the adaptive demodulation circuit includes: a signal input module 1, a power detection module 2, an adjustment module 3 and a signal demodulation module 4. The signal input module 1 is used to receive a first signal and demodulate it into a second signal; wherein the first signal includes: a carrier with signaling modulation; the second signal includes: a baseband envelope signal. The power detection module 2 is connected to the signal input module 1, and the power detection module 2 is used to generate a first control signal and a second control signal according to the power of the second signal when receiving the detection signal. The adjustment module 3 is connected to the signal input module 1 and the power detection module 2, and the adjustment module 3 is used to filter and output the second signal according to the first control signal; or output the second signal according to the second control signal. The signal demodulation module 4 is connected to the adjustment module 3 and the power detection module 2, and the signal demodulation module 4 is used to demodulate and output the second signal according to the first control signal or the second control signal; wherein the speed of demodulating the second signal according to the second control signal is faster than the speed of demodulating the second signal according to the first control signal.

[0051] Among them, when the base station sends a first signal, the signal input module 1 can receive the first signal and demodulate it. The first signal can be a carrier with signaling modulation sent by the base station, and the signal input module 1 is used to decode the baseband envelope signal modulated on the carrier. When the signal input module 1 is at different distances from the base station, the power of the carrier will also be different. For example, the closer the signal input module 1 is to the base station, the higher the power of the carrier will be, and the farther the signal input module 1 is from the base station, the lower the power of the carrier will be. Therefore, the power of the baseband envelope signal modulated on the carrier will also be different. Exemplarily, the signal input module 1 can negatively demodulate the carrier so that the power of the baseband envelope signal is inversely proportional to the power of the carrier.

[0052] In order to perform adaptive demodulation for baseband envelope signals of different powers, the power detection module 2 can receive the baseband envelope signal and detect the power. When the power detection module 2 receives the detection signal, the power detection module 2 generates a first control signal according to the power of the baseband envelope signal, and inverts the first control signal into a second control signal.

[0053] Exemplarily, the first control signal and the second control signal can be level signals. When the first control signal is a high level signal, the second control signal is a low level signal, the power of the baseband envelope signal is higher, and the power of the baseband envelope signal is inversely proportional to the power of the carrier, so the power of the carrier is smaller. At this time, the farther the distance between the signal input module 1 and the base station, the more susceptible the carrier signal is to interference and has a poor signal-to-noise ratio. The adjustment module 3 can receive the first control signal and filter the baseband envelope signal, so that the baseband envelope signal output by the adjustment module 3 has less noise interference signals. Exemplarily, the adjustment module 3 can filter by setting a filter capacitor.

[0054] The filtered baseband envelope signal can be output to the signal demodulation module 4, and the signal demodulation module 4 demodulates and outputs the baseband envelope signal according to the first control signal. Exemplarily, the signal demodulation module 4 can compare the average power of the baseband envelope signal with the actual power of the baseband envelope signal, and demodulate and output according to the comparison difference of the power.

[0055] When the first control signal is a low-level signal, the second control signal is a high-level signal, the power of the baseband envelope signal is low, and the power of the carrier is high. At this time, the distance between the signal input module 1 and the base station is relatively close, and the carrier signal has a higher signal-to-noise ratio due to its higher power, and the carrier signal is not easily interfered by noise. The adjustment module 3 can directly output the baseband envelope signal losslessly to the signal demodulation module 4, and the baseband envelope signal is demodulated and output by the signal demodulation module 4 according to the second control signal.

[0056] When the signal demodulation module 4 performs demodulation output, it is first necessary to generate the average power of the baseband envelope signal. When the signal demodulation module 4 receives the first control signal of high level, in order to prevent the demodulation circuit from deteriorating its ability to resist noise interference, a capacitor with larger capacity can be set to generate the average power. When the signal demodulation module 4 receives the second control signal of high level, it is not necessary to consider the ability to resist noise interference, and a capacitor with smaller capacity can be set to generate the average power. And the capacitor with smaller capacity can speed up the generation time of the average power. Therefore, when the power of the carrier is high, the signal demodulation module 4 can quickly demodulate the baseband envelope signal for output, and when the power of the carrier is low, the speed of the demodulation output of the signal demodulation module 4 is lower than the speed when the power of the carrier is high. Exemplarily, the signal demodulation module 4 can demodulate the signal of the analog quantity into the signal of the digital quantity.

[0057] The technical solution provided in the embodiment of the present invention realizes power detection of the first signal and the second signal by setting a power detection module 2, and generates different first control signals and second control signals according to different power sizes. The adjustment module 3 can also adaptively filter or losslessly output the second signal according to the first control signal or the second control signal. And demodulate and output through the signal demodulation module 4. The present invention can adaptively demodulate and output first signals of different powers, improve the accuracy of demodulation data when the power of the first signal is low, and improve the rapidity of demodulation when the power of the first signal is high, and has a better demodulation effect.

[0058] Figure 2 A schematic diagram of the structure of another adaptive demodulation circuit provided by an embodiment of the present invention. Figure 2 On the basis of the above embodiments, optionally, the signal input module 1 includes: an antenna 11 and a negative envelope detector 12. The antenna 11 is used to receive a first signal sent by a base station. The negative envelope detector 12 is connected to the antenna 11, and the negative envelope detector 12 is used to demodulate the first signal into a second signal; the power of the second signal is inversely proportional to the power of the first signal.

[0059] The farther the distance between the antenna 11 and the base station is, the smaller the power of the first signal is, and the closer the distance between the antenna 11 and the base station is, the greater the power of the first signal is. Exemplarily, the antenna 11 may be a tag antenna, and the base station may be a cellular base station.

[0060] When the antenna receives the first signal, the negative envelope detector 12 may output a second signal according to the first signal. For example, the negative envelope detector 12 may receive a carrier modulated with signaling, decode the baseband envelope signal modulated on the carrier, and reverse the waveform of the signal, so that the higher the carrier power, the lower the baseband envelope signal power output by the negative envelope detector 12.

[0061] Continue to refer Figure 2 On the basis of the above embodiments, optionally, the power detection module 2 includes: a first comparator 21, a trigger 22 and an inverter 23. The first input end of the first comparator 21 is used to access the reference power, and the second input end of the first comparator 21 is connected to the signal input module 1; the first comparator 21 is used to generate a first control signal according to the reference power and the power of the second signal. The input end of the trigger 22 is connected to the output end of the first comparator 21, and the control end of the trigger 22 is used to receive the detection signal and turn on the trigger 22 according to the detection signal; the output end a of the trigger 22 is connected to the adjustment module 3 and the signal demodulation module 4; the trigger 22 is used to output the first control signal when turned on. The input end of the inverter 23 is connected to the output end of the trigger 22, and the output end b of the inverter 23 is connected to the adjustment module 3 and the signal demodulation module 4; the inverter 23 is used to invert the first control signal into a second control signal and output it.

[0062] The first input terminal of the first comparator 21 may be a reverse input terminal, and the second input terminal of the first comparator 21 may be a forward input terminal. The first comparator 21 may be used to compare the reference power with the power of the second signal. The reference power may be set to different values ​​according to actual needs. For example, the reference power may be -30 dBm.

[0063] When the power of the second signal is greater than the reference power, it means that the first signal at this time has a smaller power, and the first comparator 21 can output a high-level first control signal. When the trigger 22 receives the detection signal, the trigger 22 collects the high-level first control signal and outputs it. At the same time, the inverter 23 can receive the first control signal and invert it into a low-level second control signal. The adjustment module 3 can filter the baseband envelope signal according to the high-level first control signal, so that the baseband envelope signal output by the adjustment module 3 has less noise interference signals.

[0064] When the power of the second signal is less than the reference power, it means that the first signal at this time has a larger power, and the first comparator 21 can output a low-level first control signal. When the trigger 22 receives the detection signal, the trigger 22 collects the low-level first control signal and outputs it. At the same time, the inverter 23 can receive the first control signal and invert it into a high-level second control signal. The adjustment module 3 can perform lossless output of the baseband envelope signal according to the high-level second control signal, so that the baseband envelope signal can be output more quickly.

[0065] Continue to refer Figure 2On the basis of the above embodiments, optionally, the regulating module 3 includes: a first capacitor C1, a first switch K1, a second capacitor C2 and a second switch K2. The first end of the first switch K1 is connected to the signal input module 1, the second end of the first switch K1 is connected to the first end of the first capacitor C1, the second end of the first capacitor C1 is connected to the ground end, the control end a1 of the first switch K1 is connected to the power detection module 2, and the first switch K1 is used to turn on or off according to the first control signal. The first end of the second switch K2 is connected to the signal input module 1, the second end of the second switch K2 is connected to the first end of the second capacitor C2, the second end of the second capacitor C2 is connected to the ground end, the control end b1 of the second switch K2 is connected to the power detection module 2, and the second switch K2 is used to turn on or off according to the second control signal; wherein the capacity of the first capacitor C1 is greater than the capacity of the second capacitor C2.

[0066] The control terminal a1 of the first switch K1 is connected to the output terminal a of the trigger 22 for receiving the first control signal output by the trigger 22 . The control terminal b1 of the second switch K2 is connected to the output terminal b of the inverter 23 for receiving the second control signal output by the inverter 23 .

[0067] When the first control signal is at a high level and the second control signal is at a low level, it indicates that the power of the first signal is relatively small, the antenna 11 is at a relatively long distance from the base station, and the signal-to-noise ratio of the first signal is relatively poor. The first switch K1 is turned on according to the high-level first control signal, and the second switch K2 is turned off according to the low-level second control signal, so that the first capacitor C1 can be connected to the negative envelope detector 12. Since the first capacitor C1 has a relatively large capacity, the first capacitor C1 can filter out the noise interference of the second signal output by the negative envelope detector 12.

[0068] When the first control signal is at a low level and the second control signal is at a high level, it means that the power of the first signal is relatively large, the antenna 11 is at a relatively close distance from the base station, and the signal-to-noise ratio of the first signal is relatively good. The first switch K1 is turned off according to the low-level first control signal, and the second switch K2 is turned on according to the high-level second control signal, so that the second capacitor C2 can be connected to the negative envelope detector 12. Because the second capacitor C2 has a relatively small capacity, the second signal can be transmitted losslessly. This setting may lead to an increase in noise interference power, but because the power of the first signal is high enough and the signal-to-noise ratio is good enough, it will not affect the accuracy of subsequent signal demodulation.

[0069] The present invention can adaptively connect different loops according to the power of the first signal by controlling the first switch K1 with the first control signal and controlling the second switch K2 with the second control signal, thus having a better control effect.

[0070] Continue to refer Figure 2 On the basis of the above embodiments, optionally, the signal demodulation module 4 includes: a second comparator 41, a third capacitor C3, a third switch K3, a fourth capacitor C4 and a fourth switch K4. The first input end of the second comparator 41 is connected to the adjustment module 3. The first end of the third switch K3 is connected to the second input end of the second comparator 41, the first end of the third switch K3 is also connected to the adjustment module 3, the second end of the third switch K3 is connected to the first end of the third capacitor C3, the second end of the third capacitor C3 is connected to the ground end, the control end a2 of the third switch K3 is connected to the power detection module 2, and the third switch K3 is used to turn on or off according to the first control signal. The first end of the fourth switch K4 is connected to the second input end of the second comparator 41, the first end of the fourth switch K4 is also connected to the adjustment module 3, the second end of the fourth switch K4 is connected to the first end of the fourth capacitor C4, the second end of the fourth capacitor C4 is connected to the ground end, the control end b2 of the fourth switch K4 is connected to the power detection module 2, and the fourth switch K4 is used to turn on or off according to the second control signal; wherein the capacity of the third capacitor C3 is greater than the capacity of the fourth capacitor C4, the third capacitor C3 and the fourth capacitor C4 are used to generate the power average value of the second signal, and the generation time of the power average value is positively correlated with the capacity. The second comparator 41 is used to demodulate and output the second signal according to the power of the second signal and the power average value of the second signal.

[0071] Among them, the control end a2 of the third switch K3 is connected to the output end a of the trigger 22, and is used to receive the first control signal output by the trigger 22. The control end b2 of the fourth switch K4 is connected to the output end b of the inverter 23, and is used to receive the second control signal output by the inverter 23. The first input end of the second comparator 41 can be a reverse input end, and the second input end of the second comparator 41 can be a forward input end. The first input end of the second comparator 41 receives the second signal output by the adjustment module 3. When the first control signal is high and the second control signal is low, the third switch K3 is turned on according to the high-level first control signal, and the fourth switch K4 is turned off according to the low-level second control signal, so that the third capacitor C3 can receive the second signal output by the adjustment module 3, and the third capacitor C3 can be used to obtain the average value of the power of the second signal. The second comparator 41 can demodulate and output the second signal according to the power of the second signal and the average value of the power of the second signal. Because the third capacitor C3 has a large capacitance value, the anti-noise interference ability of the demodulation circuit will not be reduced due to too small capacitance. Exemplarily, the signal after the demodulation output of the second comparator 41 can be a digital signal.

[0072] When the first control signal is at a low level and the second control signal is at a high level, the third switch K3 is turned off according to the low-level first control signal, and the fourth switch K4 is turned on according to the high-level second control signal, so that the fourth capacitor C4 can receive the second signal output by the adjustment module 3, and the fourth capacitor C4 can obtain the average value of the power of the second signal, and the second comparator 41 demodulates and outputs the second signal according to the power of the second signal and the average value of the power of the second signal. Because the capacity of the fourth capacitor C4 is smaller than the capacity of the third capacitor C3, the time for the fourth capacitor C4 to establish the average value of the power of the second signal is shorter, and the second input end of the second comparator 41 can quickly receive the average power value and demodulate and output it. This setting method has a faster demodulation speed and can avoid the distortion of the second signal during the transmission process.

[0073] Continue to refer Figure 2 On the basis of the above embodiments, optionally, the signal demodulation module 4 further includes: a first resistor R1, a first end of the first resistor R1 is connected to the adjustment module 3, a second end of the first resistor R1 is connected to the second input end of the second comparator 41, and the first resistor R1 is used for filtering.

[0074] For example, the first resistor R1 can be a low-frequency filter resistor, and the first resistor R1 can form a low-pass filter together with the third capacitor C3 or the fourth capacitor C4, which can allow low-frequency signals of a certain frequency to pass through and attenuate high-frequency signals. At the same time, the first resistor R1 can also consume part of the energy in the circuit and play a role in stabilizing the operation of the circuit.

[0075] Continue to refer Figure 2 On the basis of the above embodiments, optionally, the adaptive demodulation circuit further includes: an amplification module 5 connected between the adjustment module 3 and the signal demodulation module 4, and the amplification module 3 is used to amplify the second signal.

[0076] Exemplarily, the amplification module 5 can amplify the power of the second signal output by the regulation module 3. By setting the amplification module 5, the power of the second signal can be increased, thereby making the digital signal demodulated by the signal demodulation module 4 have higher accuracy.

[0077] Continue to refer Figure 2 On the basis of the above embodiments, optionally, the adaptive demodulation circuit further includes: a digital baseband module (not shown in the figure), connected to the power detection module 2, for receiving downlink signaling sent by the base station and generating a detection signal.

[0078] Among them, the antenna 11 can receive the first signal sent by the base station in real time. When the base station sends a downlink signal, the digital baseband module can detect the downlink signal and generate a detection signal. Exemplarily, the detection signal can be a pulse signal. At the falling edge of the pulse signal, the first comparator 21 compares the reference power with the power of the second signal and generates a first control signal, and the trigger 22 samples the first control signal and outputs it. Before the falling edge of the next pulse signal arrives, the first control signal is locked and maintained at a fixed level value until the falling edge of the next pulse signal arrives to refresh the first control signal. Through this setting method, the power detection module 2 will not cause the instability of the first control signal due to the confusion of sampling the downlink signal, and also improves the stability of the second control signal, so that the first control signal and the second control signal have a better control effect.

[0079] An embodiment of the present invention further provides an adaptive demodulation method, which is applied to the adaptive demodulation circuit provided by any embodiment of the present invention. Figure 3 A flowchart of an adaptive demodulation method provided by an embodiment of the present invention. Figure 3 , the adaptive demodulation method includes:

[0080] S110 , receiving a first signal through a signal input module and demodulating the first signal into a second signal.

[0081] The signal input module can receive a first signal sent by the base station and demodulate the first signal into a second signal. The first signal can be a carrier with signaling modulation, and the second signal can be a baseband envelope signal. The signal input module can receive a carrier with signaling modulation, decode the baseband envelope signal modulated on the carrier, and reverse the waveform of the signal. Therefore, the power of the baseband envelope signal can be negatively correlated with the carrier power.

[0082] S120. When the power detection module receives the detection signal, the power detection module generates a first control signal and a second control signal according to the power of the second signal; and outputs the first control signal to the adjustment module and the signal demodulation module, and outputs the second control signal to the adjustment module and the signal demodulation module.

[0083] Among them, the power detection module can compare the power of the second signal with the reference power. When the power of the second signal is greater than the reference power, it means that the first signal at this time has a smaller power, and the power detection module can output a high-level first control signal and a low-level second control signal. When the power of the second signal is less than the reference power, it means that the first signal at this time has a larger power, and the power detection module can output a low-level first control signal and a high-level second control signal. Therefore, the power judgment of the first signal can be realized by the first control signal and the second control signal of different levels. The adjustment module and the signal demodulation module can perform different signal processing methods according to the first control signal and the second control signal.

[0084] S130: The regulating module filters the second signal according to the first control signal and outputs the second signal to the signal demodulation module / or outputs the second signal to the signal demodulation module according to the second control signal.

[0085] Among them, when the first control signal is at a high level, the first signal has a relatively small power. At this time, the antenna is far away from the base station, and the first signal may contain more noise interference signals. The adjustment module can filter the second signal generated by demodulation of the signal input module according to the first control signal, so that the second signal output by the adjustment module can significantly reduce the noise interference signal, thereby improving the accuracy of signal demodulation.

[0086] When the second control signal is at a high level, the first signal has a large power, and at this time, the antenna and the base station are at a close distance. The adjustment module can output the second signal generated by demodulation of the signal input module losslessly according to the second control signal. Since the power of the first signal is high enough and the signal-to-noise ratio is good enough, the accuracy of subsequent signal demodulation will not be affected without filtering, and the speed of signal demodulation is improved.

[0087] S140: The signal demodulation module demodulates and outputs the second signal according to the first control signal or the second control signal.

[0088] Among them, when the signal demodulation module performs demodulation output, it is first necessary to generate the average power of the second signal. When the signal demodulation module receives the first control signal of a high level, the average power can be generated by setting a capacitor with a larger capacity, and this setting method will not reduce the ability of the demodulation circuit to resist noise interference. When the signal demodulation module receives the second control signal of a high level, there is no need to consider the ability of resisting noise interference, and the average power can be generated by setting a capacitor with a smaller capacity. At this time, the generation speed of the average power is faster, and the rapid demodulation of the second signal is realized.

[0089] The technical solution provided by the embodiment of the present invention realizes the power detection of the first signal and the second signal, and generates different first control signals and second control signals according to different power sizes. It is also possible to perform adaptive filtering or lossless output of the second signal according to the first control signal or the second control signal, and demodulate and output it through a signal demodulation module. The present invention can perform adaptive demodulation and output for first signals of different powers, improve the accuracy of demodulation data when the power of the first signal is low, and improve the rapidity of demodulation when the power of the first signal is high, and has a good demodulation effect.

[0090] Figure 4 This is a flowchart of a specific implementation method of S130 provided in an embodiment of the present invention. Figure 4 On the basis of the above embodiments, optionally, S130, the adjustment module filters the second signal according to the first control signal and outputs it to the signal demodulation module / or outputs the second signal to the signal demodulation module according to the second control signal, including:

[0091] S131, the first control signal controls the first switch to be turned on, and the second signal is output to the signal demodulation module after being filtered by the first capacitor.

[0092] When the first control signal is at a high level, it indicates that the power of the first signal is relatively small. The first switch is turned on according to the high-level first control signal, so that the first capacitor can receive the second signal and filter it. Since the first capacitor has a large capacity, the first capacitor can effectively filter out noise interference in the second signal.

[0093] S132, the second control signal controls the second switch to be turned on, and the second signal is output to the signal demodulation module via the second capacitor.

[0094] When the second control signal is at a high level, it indicates that the power of the first signal is relatively high. The second switch is turned on according to the high-level second control signal. Since the second capacitor has a relatively small capacitance value, the second signal can be transmitted losslessly with a relatively fast transmission speed. Since the power of the first signal is high enough and the signal-to-noise-interference ratio is good enough, the accuracy of subsequent signal demodulation will not be affected.

[0095] Figure 5 This is a flowchart of a specific implementation method of S140 provided in an embodiment of the present invention. Figure 5 On the basis of the above embodiments, optionally, S140, the signal demodulation module demodulates and outputs the second signal according to the first control signal or the second control signal, including:

[0096] S141. The first control signal controls the third switch to be turned on, the third capacitor generates a power average value of the second signal, and the second comparator demodulates and outputs the second signal according to the power of the second signal and the power average value of the second signal.

[0097] Among them, when the first control signal is at a high level, the third switch is turned on according to the high-level first control signal, so that the third capacitor can receive the second signal output by the adjustment module, and the third capacitor can obtain the average value of the second signal power, and the second signal can be demodulated and output according to the power of the second signal and the average value of the power of the second signal. Because the third capacitor has a large capacitance value, the anti-noise interference ability of the demodulation circuit can still be maintained in a good state.

[0098] S142: The second control signal controls the fourth switch to be turned on, the fourth capacitor generates an average power value of the second signal, and the second comparator demodulates and outputs the second signal according to the power of the second signal and the average power value of the second signal.

[0099] Among them, when the second control signal is at a high level, the fourth switch is turned on according to the high-level second control signal, so that the fourth capacitor can receive the second signal output by the adjustment module, and the fourth capacitor can obtain the average value of the second signal power, and the second signal can be demodulated and output according to the power of the second signal and the average power of the second signal. Because the capacity of the fourth capacitor is smaller than that of the third capacitor, the time for the fourth capacitor to establish the average power of the second signal is shorter, and the signal demodulation module can demodulate and output faster.

[0100] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0101] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An adaptive demodulation circuit, characterized in that: include: A signal input module, used for receiving a first signal and demodulating it into a second signal; wherein the first signal includes: a carrier with signaling modulation; the second signal includes: a baseband envelope signal; A power detection module, the power detection module is connected to the signal input module, and the power detection module is used to generate a first control signal and a second control signal according to the power of the second signal when receiving the detection signal; an adjustment module connected to the signal input module and the power detection module, the adjustment module being used to filter and output the second signal according to the first control signal; or to output the second signal according to the second control signal; A signal demodulation module is connected to the adjustment module and the power detection module, and the signal demodulation module is used to demodulate and output the second signal according to the first control signal or the second control signal; wherein, a speed of demodulating the second signal according to the second control signal is faster than a speed of demodulating the second signal according to the first control signal.

2. The adaptive demodulation circuit according to claim 1, characterized in that: The signal input module comprises: An antenna, used to receive the first signal sent by the base station; A negative envelope detector is connected to the antenna, and is used to demodulate the first signal into the second signal; the power of the second signal is inversely proportional to the power of the first signal.

3. The adaptive demodulation circuit according to claim 1, characterized in that: The power detection module comprises: a first comparator, wherein a first input end of the first comparator is used to access a reference power, and a second input end of the first comparator is connected to the signal input module; the first comparator is used to generate the first control signal according to the reference power and the power of the second signal; A trigger, wherein the input end of the trigger is connected to the output end of the first comparator, the control end of the trigger is used to receive the detection signal and turn on the trigger according to the detection signal; the output end of the trigger is connected to the adjustment module and the signal demodulation module; the trigger is used to output the first control signal when turned on; An inverter, wherein the input end of the inverter is connected to the output end of the trigger, and the output end of the inverter is connected to the regulation module and the signal demodulation module; the inverter is used to invert the first control signal into the second control signal and output it.

4. The adaptive demodulation circuit according to claim 1, characterized in that: The adjustment module comprises: a first capacitor and a first switch, wherein a first end of the first switch is connected to the signal input module, a second end of the first switch is connected to a first end of the first capacitor, a second end of the first capacitor is connected to a ground terminal, a control end of the first switch is connected to the power detection module, and the first switch is used to be turned on or off according to the first control signal; A second capacitor and a second switch, wherein the first end of the second switch is connected to the signal input module, the second end of the second switch is connected to the first end of the second capacitor, the second end of the second capacitor is connected to the ground end, the control end of the second switch is connected to the power detection module, and the second switch is used to turn on or off according to the second control signal; wherein the capacity of the first capacitor is greater than the capacity of the second capacitor.

5. The adaptive demodulation circuit according to claim 1, characterized in that: The signal demodulation module comprises: A second comparator, wherein a first input terminal of the second comparator is connected to the regulating module; a third capacitor and a third switch, wherein a first end of the third switch is connected to the second input end of the second comparator, a first end of the third switch is also connected to the regulating module, a second end of the third switch is connected to the first end of the third capacitor, a second end of the third capacitor is connected to the ground end, a control end of the third switch is connected to the power detection module, and the third switch is used to be turned on or off according to the first control signal; a fourth capacitor and a fourth switch, wherein a first end of the fourth switch is connected to the second input end of the second comparator, a first end of the fourth switch is also connected to the regulating module, a second end of the fourth switch is connected to the first end of the fourth capacitor, a second end of the fourth capacitor is connected to the ground end, a fourth switch control end is connected to the power detection module, and the fourth switch is used to turn on or off according to the second control signal; wherein the capacity of the third capacitor is greater than that of the fourth capacitor, the third capacitor and the fourth capacitor are used to generate a power average value of the second signal, and the generation time of the power average value is positively correlated with the capacity; The second comparator is used for demodulating and outputting the second signal according to the power of the second signal and an average power value of the second signal.

6. The adaptive demodulation circuit according to claim 5, characterized in that: The signal demodulation module also includes: A first resistor, wherein a first end of the first resistor is connected to the regulating module, a second end of the first resistor is connected to the second input end of the second comparator, and the first resistor is used for filtering.

7. The adaptive demodulation circuit according to claim 1, characterized in that: The adaptive demodulation circuit also includes: An amplification module is connected between the adjustment module and the signal demodulation module, and is used to amplify the second signal.

8. The adaptive demodulation circuit according to claim 1, characterized in that: The adaptive demodulation circuit further includes: a digital baseband module connected to the power detection module, configured to receive downlink signaling sent by a base station and generate the detection signal.

9. An adaptive demodulation method, characterized in that: Applicable to the adaptive demodulation circuit as claimed in any one of claims 1 to 8; The adaptive demodulation method comprises: Receive a first signal through a signal input module and demodulate the first signal into a second signal; wherein the first signal includes: a carrier with signaling modulation; the second signal includes: a baseband envelope signal; When the power detection module receives the detection signal, the power detection module generates a first control signal and a second control signal according to the power of the second signal; and outputs the first control signal to the adjustment module and the signal demodulation module, and outputs the second control signal to the adjustment module and the signal demodulation module; The regulating module filters the second signal according to the first control signal and outputs the second signal to the signal demodulation module / or outputs the second signal to the signal demodulation module according to the second control signal; The signal demodulation module demodulates and outputs the second signal according to the first control signal or the second control signal; wherein a speed of demodulating the second signal according to the second control signal is faster than a speed of demodulating the second signal according to the first control signal.

10. The adaptive demodulation method according to claim 9, characterized in that: The regulating module filters the second signal according to the first control signal and outputs it to the signal demodulation module / or outputs the second signal to the signal demodulation module according to the second control signal, including: The first control signal controls the first switch to be turned on, and the second signal is output to the signal demodulation module after being filtered by the first capacitor; The second control signal controls the second switch to be turned on, and the second signal is output to the signal demodulation module via the second capacitor: The signal demodulation module demodulates and outputs the second signal according to the first control signal or the second control signal, including: The first control signal controls the third switch to be turned on, the third capacitor generates a power average value of the second signal, and the second comparator demodulates and outputs the second signal according to the power of the second signal and the power average value of the second signal; The second control signal controls the fourth switch to be turned on, the fourth capacitor generates an average power value of the second signal, and the second comparator demodulates and outputs the second signal according to the power of the second signal and the average power value of the second signal.

Images