Task
Figure 1 Task content
Require
Figure 2 Contents of basic requirements
Figure 3 play part of the content
illustrate
Figure 4 Explanation content
Grading
Figure 5 Score content
text (part)
Summary
The purpose of this experiment is to design and manufacture a device for identifying the modulation mode and estimating the parameters of the signal output by the signal generator. The device can identify and display the modulation mode of the signal, and output the demodulated signal for the oscilloscope to observe the waveform. The implementation method of the system is built by using STM32F407 main control and AD9910 chip. Experimental tasks include modulation identification and parameter estimation for AM and FM signals, and signal identification under unknown modulation. Experimental requirements include displaying modulation modes and related parameters, outputting demodulated signals for observation, and autonomously identifying different keying modes. Through this experiment, it is possible to improve the ability to identify the signal modulation method and estimate the parameters.
Keywords: signal modulation identification, parameter estimation, STM32F407 master control, AD9910 chip, demodulation signal
1.1 Demonstration and selection of the main control module
Option 1: Select STM32F407 master control
Advantages: stable performance, sufficient processing power and interface scalability
Disadvantages: higher price
Solution 2: Select STM32F103 master control
Advantages: cost-effective, complete functions
Disadvantages: relatively weak processing power
Solution 3: Select STM32F303 master control
Advantages: low power consumption, suitable for embedded applications
Disadvantages: fewer interfaces, poor scalability
To sum up, option one is the most reasonable, because the STM32F407 main control has stable performance and strong processing capability, which can meet the needs of signal modulation identification and parameter estimation devices.
1.2 Demonstration and selection of hardware control scheme
Solution 1: Use the AD9833 chip to build the system, and use the following hardware modules to realize the functions
Signal generator module: AD9833 chip
Signal processing blocks: filters, amplifiers
Display module: LCD display
Solution 2: Use the AD9850 chip to build the system, and use the following hardware modules to realize the functions
Signal generator module: AD9850 chip
Signal processing blocks: filters, amplifiers
Display module: digital tube display
Solution 3: Use the AD9910 chip to build the system, and use the following hardware modules to realize the functions
Signal generator module: AD9910 chip
Signal processing blocks: filters, amplifiers
Display module: OLED display
To sum up, the third option is the most reasonable, because the AD9910 chip has high precision and frequency range, which can meet the needs of signal modulation identification and parameter estimation devices.
2.2 Calculation of FM coefficient mf and maximum frequency offset max f
The frequency modulation coefficient mf is defined as the ratio of the frequency change of the frequency modulation signal to the change of the carrier frequency. The maximum frequency deviation max f is defined as the maximum difference between the FM signal frequency and the carrier frequency. According to the known conditions, the uM output by the signal generator is an FM signal, and its modulation signal frequency F = 5kHz. We can calculate the frequency modulation coefficient mf and the maximum frequency deviation max f by measuring the peak-to-peak value of the demodulated signal uo.
Assume that the peak-to-peak value of the demodulated signal uo is Vpp. According to the definition of frequency modulation coefficient mf and maximum frequency deviation max f, we have:
mf = (Δf) / F
max f = max(Δf)
Among them, Δf is the frequency variation of the demodulated signal, and F is the frequency of the modulated signal. The modulation signal frequency F is known to be 5kHz.
4. Test plan and test results
4.1 Test scheme
4.1.1 Functional test
(1) AM method identification and parameter estimation test
1. Set the signal generator output as AM signal, frequency F=1kHz.
2. Connect the output signal to the device for identification and parameter estimation.
3. Check whether the device successfully displays the amplitude modulation coefficient ma and outputs the demodulation signal uo.
(2) FM mode identification and parameter estimation test
1. Set the signal generator output as FM signal, frequency F=5kHz.
2. Connect the output signal to the device for identification and parameter estimation.
3. Check whether the device successfully displays the frequency modulation coefficient mf and the maximum frequency deviation max f, and outputs the demodulated signal uo.
(3) Self-recognition modulation mode test
1. Set the output of the signal generator as a signal with an unknown modulation method.
2. Connect the output signal to the device for autonomous identification.
3. Check whether the device successfully displays the modulation mode.
(4) Parameter estimation test
1. Set the signal generator output as AM or FM signal, and the frequency F is 1kHz, 2kHz, 3kHz, 4kHz or 5kHz.
2. Connect the output signal to the device for parameter estimation.
3. According to the identified modulation method, check whether the device successfully displays the corresponding parameters (amplitude modulation coefficient ma, frequency modulation coefficient mf, maximum frequency deviation max f) and outputs the demodulated signal uo.
(5) Keying method identification and parameter estimation test (play part)
1. Set the signal generator output as 2ASK, 2PSK or 2FSK signal, the peak-to-peak value of the carrier voltage is 100mV, and the carrier frequency cf is 2MHz.
2. Connect the output signal to the device for keying mode identification and parameter estimation.
3. According to the identified keying mode, check whether the device successfully displays the corresponding parameters (binary code rate Rc, frequency shift keying coefficient h) and outputs the demodulated signal uo.
This document gives only part of the content, if you want a complete document, you can pay attention to it and send a private message. to get it.
In fact, rigid standards cannot limit us with infinite possibilities, so ah! Come on boys!
Task
Figure 1 Task content
Require
Figure 2 Contents of basic requirements
Figure 3 play part of the content
illustrate
Figure 4 Explanation content
Grading
Figure 5 Score content
text (part)
Summary
The purpose of this experiment is to design and manufacture a device for identifying the modulation mode and estimating the parameters of the signal output by the signal generator. The device can identify and display the modulation mode of the signal, and output the demodulated signal for the oscilloscope to observe the waveform. The implementation method of the system is built by using STM32F407 main control and AD9910 chip. Experimental tasks include modulation identification and parameter estimation for AM and FM signals, and signal identification under unknown modulation. Experimental requirements include displaying modulation modes and related parameters, outputting demodulated signals for observation, and autonomously identifying different keying modes. Through this experiment, it is possible to improve the ability to identify the signal modulation method and estimate the parameters.
Keywords: signal modulation identification, parameter estimation, STM32F407 master control, AD9910 chip, demodulation signal
1.1 Demonstration and selection of the main control module
Option 1: Select STM32F407 master control
Advantages: stable performance, sufficient processing power and interface scalability
Disadvantages: higher price
Solution 2: Select STM32F103 master control
Advantages: cost-effective, complete functions
Disadvantages: relatively weak processing power
Solution 3: Select STM32F303 master control
Advantages: low power consumption, suitable for embedded applications
Disadvantages: fewer interfaces, poor scalability
To sum up, option one is the most reasonable, because the STM32F407 main control has stable performance and strong processing capability, which can meet the needs of signal modulation identification and parameter estimation devices.
1.2 Demonstration and selection of hardware control scheme
Solution 1: Use the AD9833 chip to build the system, and use the following hardware modules to realize the functions
Signal generator module: AD9833 chip
Signal processing blocks: filters, amplifiers
Display module: LCD display
Solution 2: Use the AD9850 chip to build the system, and use the following hardware modules to realize the functions
Signal generator module: AD9850 chip
Signal processing blocks: filters, amplifiers
Display module: digital tube display
Solution 3: Use the AD9910 chip to build the system, and use the following hardware modules to realize the functions
Signal generator module: AD9910 chip
Signal processing blocks: filters, amplifiers
Display module: OLED display
To sum up, the third option is the most reasonable, because the AD9910 chip has high precision and frequency range, which can meet the needs of signal modulation identification and parameter estimation devices.
2.2 Calculation of FM coefficient mf and maximum frequency offset max f
The frequency modulation coefficient mf is defined as the ratio of the frequency change of the frequency modulation signal to the change of the carrier frequency. The maximum frequency deviation max f is defined as the maximum difference between the FM signal frequency and the carrier frequency. According to the known conditions, the uM output by the signal generator is an FM signal, and its modulation signal frequency F = 5kHz. We can calculate the frequency modulation coefficient mf and the maximum frequency deviation max f by measuring the peak-to-peak value of the demodulated signal uo.
Assume that the peak-to-peak value of the demodulated signal uo is Vpp. According to the definition of frequency modulation coefficient mf and maximum frequency deviation max f, we have:
mf = (Δf) / F
max f = max(Δf)
Among them, Δf is the frequency variation of the demodulated signal, and F is the frequency of the modulated signal. The modulation signal frequency F is known to be 5kHz.
4. Test plan and test results
4.1 Test scheme
4.1.1 Functional test
(1) AM method identification and parameter estimation test
1. Set the signal generator output as AM signal, frequency F=1kHz.
2. Connect the output signal to the device for identification and parameter estimation.
3. Check whether the device successfully displays the amplitude modulation coefficient ma and outputs the demodulation signal uo.
(2) FM mode identification and parameter estimation test
1. Set the signal generator output as FM signal, frequency F=5kHz.
2. Connect the output signal to the device for identification and parameter estimation.
3. Check whether the device successfully displays the frequency modulation coefficient mf and the maximum frequency deviation max f, and outputs the demodulated signal uo.
(3) Self-recognition modulation mode test
1. Set the output of the signal generator as a signal with an unknown modulation method.
2. Connect the output signal to the device for autonomous identification.
3. Check whether the device successfully displays the modulation mode.
(4) Parameter estimation test
1. Set the signal generator output as AM or FM signal, and the frequency F is 1kHz, 2kHz, 3kHz, 4kHz or 5kHz.
2. Connect the output signal to the device for parameter estimation.
3. According to the identified modulation method, check whether the device successfully displays the corresponding parameters (amplitude modulation coefficient ma, frequency modulation coefficient mf, maximum frequency deviation max f) and outputs the demodulated signal uo.
(5) Keying method identification and parameter estimation test (play part)
1. Set the signal generator output as 2ASK, 2PSK or 2FSK signal, the peak-to-peak value of the carrier voltage is 100mV, and the carrier frequency cf is 2MHz.
2. Connect the output signal to the device for keying mode identification and parameter estimation.
3. According to the identified keying mode, check whether the device successfully displays the corresponding parameters (binary code rate Rc, frequency shift keying coefficient h) and outputs the demodulated signal uo.
This document gives only part of the content, if you want a complete document, you can pay attention to it and send a private message. to get it.
In fact, rigid standards cannot limit us with infinite possibilities, so ah! Come on boys!