CN201993961U - Open communication theory test platform - Google Patents
Open communication theory test platform Download PDFInfo
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- CN201993961U CN201993961U CN2011200583365U CN201120058336U CN201993961U CN 201993961 U CN201993961 U CN 201993961U CN 2011200583365 U CN2011200583365 U CN 2011200583365U CN 201120058336 U CN201120058336 U CN 201120058336U CN 201993961 U CN201993961 U CN 201993961U
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Abstract
The utility model discloses an open communication theory test platform, which comprises a plurality of communication theory test modules, a power source and a signal frequency conversion module. The signal frequency conversion module is provided with a crystal oscillator, a control signal interface and a CPLD (complex programmable logic device) EPM7064 of Altera, the control signal interface can be connected with a control computer directly, codes of a signal frequency converting function are downloaded to the CPLD EPM7064 from the control computer, input end test module signals are subjected to frequency conversion to obtain frequency signals required by an output end test module, mutual fit of frequencies and code rates of the test modules in a communication theory comprehensive test by using the signal frequency conversion module, and the traditional test teaching mode is changed by flexible application of the CPLD, so that students can better master and be well acquainted with composition, operating principle and performance of a communication system.
Description
Technical field
The utility model relates to a kind of experiment porch, especially relates to a kind of open communication principle experiment porch.
Background technology
Principle of Communication is the course that a theoretical property is strong, content is more abstract, is provided with the knowwhy of communication theory experiment class to help student's perceptual knowledge to be learned for this reason.The basic comprising of several communication theory experiment casees that provide on the home market is similar at present, structure is as follows: experimental box is equipped with some dismountable experiment modules, these modules make up can constitute with correlation theories knowledge mutually puts separate unit experiment one to one, as the PCM(pulse code modulation (PCM)) experiment, the PAM(pulse-amplitude modulation) experiment, code conversion experiment etc., producer is in order to save manufacturing cost, the frequency of input/output signal between each unit experiment module, bit rate is incomplete same, it is inequality promptly to go up the required frequency input signal of the output signal frequency of a module and next module, can not mate compatibility each other, so can't simulate the experiment of practical communication complete procedure.
Traditional communication system is by unify two kinds of analog communication systems of digital communication department.Wherein, point-to-point digital communication system model is shown in Fig. 1.Among Fig. 1, information source is a digital signal.Encryption equipment is used for ensuring information security, and this experiment does not relate to.Digital signal is through the HDB3(High Density Bipolar 3) coding, deliver in the modulator, by the FSK(frequency shift keying) or the PSK(phase-shift keying (PSK)) modulate and send into Channel Transmission, according to inverse process signal integrity is accepted again.In the communication theory experiment class, each part mentioned above all independently carries out, and all has the unmatched problem of frequency between each module.Analog signal digital transport communication system as shown in Figure 2.Among Fig. 2, information source is a simulating signal, so will pass through PAM, PCM module earlier, changes into digital signal after sampling, quantification, the coding, sends into digital communication system again and transmits.There are the unmatched problem of frequency equally in the PAM here, PCM module and transport module thereafter.
Because the frequency mismatch problem that exists between each unit experiment module, the student lacks understanding to the communication overall process, can only be scattered understand each knowledge point, the knowledge of grasp is more in disorder, lacks systematicness and integrality.
Summary of the invention
Technical problem to be solved in the utility model provides a kind of signal frequency conversion module that is provided with, can carry out frequency transformation to the signal of each experiment module output so that itself and next separate unit is tested required frequency, bit rate is complementary, reach each separate unit experiment module is connected in series the open communication principle experiment porch of finishing a complete communication system Comprehensive Experiment by the practical communication overall process.
The utility model solves the problems of the technologies described above the technical scheme that is adopted: a kind of open communication principle experiment porch, comprise a plurality of communication theory experiment modules, power supply and signal frequency conversion module, described signal frequency conversion module is connected with described power supply, described signal frequency conversion module is provided with control signal interface and a plurality of experiment module interface, and described experiment module interface is connected with described communication theory experiment module respectively.
Described communication theory experiment module comprises simulation signal generator experiment module, multiple modulation experiment module, multiple coding and decoding experiment module, code conversion experiment module, digital time-division exchange test module, synchronous experiment module, low frequency filtering experiment module, eye pattern observation experiment module and audio frequency amplification test module.
Described multiple modulation experiment module comprises FSK preparation test module and FSK demodulation experiment module, and described multiple coding and decoding experiment module comprises pcm encoder experiment module, PCM decoding experiment module, HDB3 coding experiment module and HDB3 decoding experiment module.
Described signal frequency conversion module is provided with crystal oscillator, is used for producing 16.384MHz system major clock.
Described control signal interface is used for downloading the code of realizing frequency conversion function.
Described control signal interface is connected with control computer.
Described signal frequency conversion module is provided with the CPLD programming device, and described CPLD programming device is selected the CPLD programming device EPM7064 of ALTERA company for use.
Described CPLD programming device EPM7064 is provided with 32 I/O mouths, is used for importing the signal of the required change frequency of each experiment module and the signal of the required frequency of each experiment module of output.
Compared with prior art, advantage of the present utility model is: the signal frequency conversion module that is provided with in the open communication principle experiment porch, can carry out frequency transformation to the signal of the output of each experiment module according to requirement of experiment, independently the frequency between the experiment module, bit rate are mated mutually to make in the experiment each; The flexible Application of CPLD programming device, improved the utilization factor of experimental box, changed traditional Experiment Teaching Mode, the brand-new experiment mode of thinking is provided, help developing innovation ability of students, enriched experiment content, make the selectivity of autonomous experiment, dirigibility stronger, help composition, principle of work and performance characteristics that the student grasps communication system better, and digest.
During experimental implementation, I/O mouth to described CPLD programming device EPM7064 is imported according to the experiment needs, the distribution of delivery outlet, distribute several to import one to one, delivery outlet, the signal output that last needs is changed the experiment module of signal frequency is electrically connected with input port in the described signal frequency conversion module, the corresponding delivery outlet of described signal frequency conversion module is electrically connected with the signal input of next experiment module, according to the relation that connects, on control computer Quartus II software platform, write the code that to realize frequency conversion function with VHDL language, it is downloaded to the function that realizes the signal frequency conversion module among the CPLD programming device EPM7064 by the control signal interface.
During experimental implementation, distribute input at aforesaid operations, on the basis of delivery outlet, at least one signal output that need change the experiment module of signal frequency is electrically connected respectively with corresponding input port in the described signal frequency conversion module, the corresponding delivery outlet of described signal frequency conversion module is electrically connected with the signal input of at least one next experiment module, according to the relation that connects, on control computer Quartus II software platform, write the code that to realize frequency conversion function with VHDL language, described control signal interface directly links to each other with described control computer, the code of realizing frequency conversion function can be downloaded among the CPLD programming device EPM7064, realize the input of one group of above experiment module correspondence, the frequency conversion function of delivery outlet, and can directly on control computer, revise the code of realizing frequency conversion function, easy to operate.
Description of drawings
Fig. 1 is a digital communication system model synoptic diagram.
Fig. 2 is an analog communication system model synoptic diagram.
Fig. 3 is the utility model signal frequency conversion module diagram.
Fig. 4 is a CPLD programming device EPM7064 pin Pareto diagram in the utility model signal frequency conversion module.
Phase-locked loop module when Fig. 5 realizes frequency conversion function for the utility model in the Quartus II software platform.
Fig. 6 is the utility model Typical Digital frequency band transmission system chart.
Fig. 7 is the utility model Typical Digital baseband transmission system block diagram.
Embodiment
Embodiment describes in further detail the utility model below in conjunction with accompanying drawing.
As shown in Figure 3, signal frequency conversion module 8 is provided with CPLD programming device EPM7064 13, CPLD programming device EPM7064 13 has 44 pins, 32 universaling I/O port pins are wherein arranged, these I/O mouth pins are connected with each experiment module respectively as a plurality of experiment module interfaces of CPLD programming device EPM7064 13, GAND10, GAND22, GAND30, GAND42 is a grounding pin, VCC3, VCC15, VCC23, VCC35 is for connecing power pins, IO/TDO38, IO/TDI7, IO/TCK32, IO/TMS13 is corresponding test pin, also can be used as the universaling I/O port pin and uses.Signal frequency conversion module 8 is provided with crystal oscillator 11, be used for producing system's major clock of 16.384MHz, crystal oscillator 11 is input among the CPLD programming device EPM7064 13 by INPUT/GCLK1 43 pins, crystal oscillator 11 cooperates CPLD programming device EPM7064 13 work, needed various clock signals of each experiment module that CPLD programming device EPM7064 13 produces and digital signal are all synchronous with system's major clock that crystal oscillator 11 produces, the signal of need change frequency is input among the CPLD programming device EPM7064 13 by the universaling I/O port pin of appointment, signal frequency conversion module 8 realizes that signal frequency conversion functional programs code can download in CPLD programming device EPM7064 13 chips by control signal interface 16, then by the signal after the universaling I/O port pin output frequency conversion of appointment.
Figure 4 shows that the chip pin figure of CPLD programming device EPM7064 13.This chip has 44 pins, and each road signal can pass through the input and output of I/O pin.In this chip, can adopt VHDL language to write frequency division and frequency multiplication program, to reach the purpose of frequency conversion.
Division function is achieved as follows: suppose the square-wave signal of I/O pin 5 input 2KHz, the needed square-wave signal of I/O pin 6 outputs.A signal variable a is set, and when rising edge of a pulse arrived, this variable was established a signal variable b in addition again from increasing one, if carry out 2 frequency divisions, and then when variable a is added to 1, variable b negate, variable a zero clearing, I/O pin 6 exportable 1KHz square waves at this moment; If carry out 4 frequency divisions, then when variable a is added to 2, variable b negate, variable a zero clearing, I/O pin 6 exportable 250Hz square waves at this moment; And the like.
Double frequency function is achieved as follows: mainly used the phase-locked loop module in the Quartus II software platform here, following Fig. 3.Inclk0 represents input signal; Ratio can be provided with voluntarily, but is required to be integer, and is popular, and this is the enlargement factor to input signal; C0 is an output signal.Suppose that Inclk0 is 50MHz, Ratio is 4, and C0 is 4*50MHz=200 MHz, has just carried out 4 frequencys multiplication.Phase-locked loop module can be used to improve frequency input signal, reaches the frequency multiplication purpose.Inclk0, C0 are configurable to the I/O pin, can finish double frequency function.
Pcm encoder experiment module 2 for Fig. 6, output signal frequency is 2.048MHz, and next FSK preparation test module 3 required frequencies are 2KHz, can carry out frequency division to pcm encoder experiment module 2 output signals of 2.048MHz, divide ratio is 1024, can obtain required signal frequency.FSK demodulation experiment module 4 and for example, output signal frequency is 2KHz, next PCM decoding experiment module 5 required frequencies are 2.048MHz, then can carry out frequency multiplication to the output signal of FSK demodulation experiment module 4, Clock Multiplier Factor is 1024, can obtain the input signal of the PCM decoding experiment module 5 of 2.048MHz.Equally, for several experiment modules of Fig. 7, also can adopt above-mentioned frequency multiplication dividing method to realize.
Each experiment module is Nanjing and moistens experiment module unit in the RZ8631 type experimental box that many companies produce among Fig. 6, Fig. 7.
As shown in Figure 6, be a Typical Digital frequency band transmission system, simulation signal generator experiment module 1 among the figure; Pcm encoder experiment module 2; FSK preparation test module 3; FSK demodulation experiment module 4; PCM deciphers experiment module 5; Low frequency filtering experiment module 6; Audio frequency amplification test module 7; Signal frequency conversion module 8; Noise source 9; Synchronous experiment module 10.Wherein, signal frequency conversion module 8 is a nucleus module.During transmission system work, simulation signal generator experiment module 1 carries out coded modulation by the P703 interface to pcm encoder experiment module 2 input analog voice signals, DX interface output frequency is the transmission signals of 2.048MHz, the DX interface is electrically connected with the I/O24 pin of signal frequency conversion module 8, the signal input signal frequency-variable module 8 that is about to 2.048MHz carries out frequency division, the 2P01 interface of I/O25 pin with FSK preparation test module 3 is electrically connected, with frequency conversion later frequency is that the signal input FSK preparation test module 3 of 2KHz is modulated, modulation signal frequency later is 2KHz, 2P06 interface and 3P01 interface is electrically connected combines noise source 9 and come the analogue communication channel, the signal of 2KHz is sent into FSK demodulation experiment module 4 carry out demodulation, signal frequency after the 3P02 interface output demodulation is 2KHz, the 3P02 interface is electrically connected with the I/O26 pin of signal frequency conversion module 8, the signal input signal frequency-variable module 8 that is about to 2KHz carries out frequency multiplication, the DR interface of I/O27 pin with PCM decoding experiment module 5 is electrically connected, with frequency conversion later frequency is that the signal input PCM decoding experiment module 5 of 2.048MHz is deciphered processing, signal after the decoding is through the output of VFRO interface, the VFRO interface of PCM being deciphered experiment module 5 is electrically connected with the P603 interface of low frequency filtering experiment module 6, signal is sent into low frequency filtering experiment module 6 and is carried out Filtering Processing, the P604 interface of low frequency filtering experiment module 6 is electrically connected with the SIN interface of audio frequency amplification test module 7, signal is sent into audio frequency amplification test module 7 carry out the power amplification processing, the SOUT interface by audio frequency amplification test module 7 is connected the output voice signal with loudspeaker at last.
As shown in Figure 7, be a Typical Digital baseband transmission system, simulation signal generator experiment module 1 among the figure; Pcm encoder experiment module 2; The HDB3 experiment module 14 of encoding; HDB3 deciphers experiment module 15; PCM deciphers experiment module 5; Low frequency filtering experiment module 6; Audio frequency amplification test module 7; Signal frequency conversion module 8; Noise source 9; Synchronous experiment module 10.Wherein, signal frequency conversion module 8 is a nucleus module.During transmission system work, simulation signal generator experiment module 1 carries out coded modulation by the P703 interface to pcm encoder experiment module 2 input analog voice signals, DX interface output frequency is the transmission signals of 2.048MHz, the DX interface is electrically connected with the I/O28 pin of signal frequency conversion module 8, the signal input signal frequency-variable module 8 that is about to 2.048MHz carries out frequency division, the P301 interface of I/O29 pin with HDB3 coding experiment module 14 is electrically connected, with frequency conversion later frequency is that the signal input HDB3 coding experiment module 14 of 32KHz is encoded, coding signal frequency later is 32KHz, P302 interface and P305 interface is electrically connected combines noise source 9 and come the analogue communication channel, the signal of 32KHz is sent into HDB3 decoding experiment module 15 decipher processing, signal frequency after the P306 interface output decoding is 32KHz, the P306 interface is electrically connected with the I/O31 pin of signal frequency conversion module 8, the signal input signal frequency-variable module 8 that is about to 32KHz carries out frequency multiplication, the DR interface of I/O33 pin with PCM decoding experiment module 5 is electrically connected, with frequency conversion later frequency is that the signal input PCM decoding experiment module 5 of 2.048MHz is deciphered processing, signal after the decoding is through the output of VFRO interface, the VFRO interface of PCM being deciphered experiment module 5 is electrically connected with the P603 interface of low frequency filtering experiment module 6, signal is sent into low frequency filtering experiment module 6 and is carried out Filtering Processing, the P604 interface of low frequency filtering experiment module 6 is electrically connected with the SIN interface of audio frequency amplification test module 7, signal is sent into audio frequency amplification test module 7 carry out the power amplification processing, the SOUT interface by audio frequency amplification test module 7 is connected the output voice signal with loudspeaker at last.
Embodiment of the present utility model is not limited to above-mentioned two kinds, can also be the integrated communication principle experiment of forming between experiment module such as code conversion experiment module, digital time-division exchange test module and eye pattern observation experiment module and other each experiment module, the realization principle of its frequency conversion function be identical with the above embodiments.
Claims (7)
1. open communication principle experiment porch, comprise a plurality of communication theory experiment modules and power supply, it is characterized in that also being provided with the signal frequency conversion module, described signal frequency conversion module is connected with described power supply, described signal frequency conversion module is provided with control signal interface and a plurality of experiment module interface, and described experiment module interface is connected with described communication theory experiment module respectively.
2. a kind of open communication principle experiment porch according to claim 1 is characterized in that described communication theory experiment module comprises simulation signal generator experiment module, multiple modulation experiment module, multiple coding and decoding experiment module, code conversion experiment module, digital time-division exchange test module, synchronous experiment module, low frequency filtering experiment module, eye pattern observation experiment module and audio frequency amplification test module.
3. a kind of open communication principle experiment porch according to claim 2, it is characterized in that described multiple modulation experiment module comprises FSK preparation test module and FSK demodulation experiment module, described multiple coding and decoding experiment module comprises pcm encoder experiment module, PCM decoding experiment module, HDB3 coding experiment module and HDB3 decoding experiment module.
4. a kind of open communication principle experiment porch according to claim 1 is characterized in that described signal frequency conversion module is provided with crystal oscillator, is used for producing 16.384MHz system major clock.
5. a kind of open communication principle experiment porch according to claim 1 is characterized in that described control signal interface is connected with control computer.
6. a kind of open communication principle experiment porch according to claim 1 is characterized in that described signal frequency conversion module is provided with the CPLD programming device, and described CPLD programming device is selected the CPLD programming device EPM7064 of ALTERA company for use.
7. a kind of open communication principle experiment porch according to claim 6, it is characterized in that described CPLD programming device EPM7064 is provided with 32 I/O mouths, be used for importing the signal of the required change frequency of each experiment module and the signal of the required frequency of each experiment module of output.
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| CN2011200583365U CN201993961U (en) | 2011-03-08 | 2011-03-08 | Open communication theory test platform |
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| CN2011200583365U CN201993961U (en) | 2011-03-08 | 2011-03-08 | Open communication theory test platform |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102129803A (en) * | 2011-03-08 | 2011-07-20 | 宁波大学 | Open communication principle experimental platform |
| CN103377577A (en) * | 2012-04-19 | 2013-10-30 | 北京泛华恒兴科技有限公司 | Experimental platform |
-
2011
- 2011-03-08 CN CN2011200583365U patent/CN201993961U/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102129803A (en) * | 2011-03-08 | 2011-07-20 | 宁波大学 | Open communication principle experimental platform |
| CN103377577A (en) * | 2012-04-19 | 2013-10-30 | 北京泛华恒兴科技有限公司 | Experimental platform |
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Granted publication date: 20110928 Termination date: 20140308 |