Background technology
Cover in the process of measuring at radio and television, broadcast television signal power is a very important technical indicator, is the important references of assessment broadcast television signal quality, and in prior art, broadcast television signal power measurement scheme has following two kinds:
Referring to Fig. 3, for the first prior art, to use the measuring equipment of the specialties such as frequency spectrograph to carry out signal power measurement, its process is: first broadcast singal is sent to radio and television test receiver and spectrum analyzer, test datas such as rate of false alarm, the error rate, signal to noise ratios is sent to data acquisition module by radio and television test receiver, the signal power recording is sent to data acquisition module by spectrum analyzer, above-mentioned test data is sent to host computer by data acquisition module, to realize the power measurement of TV signal.Although this kind utilizes the method for measurement measurement result precision of spectrum analyzer higher, frequency spectrograph cost is higher, and conventionally covers the field testing that measurement need to be a large amount of, and frequency spectrograph is heavier, and belongs to accurate apparatus, so be difficult for portable;
Referring to Fig. 4, for the second prior art, it is the signal strength signal intensity assessment function that utilizes broadcast television channel demodulation chip, carry out measured signal power, its process is: broadcast singal sends to radio and television test receiver, radio and television test receiver comprises tuner, channel demodulation module and control and data-interface, broadcast singal first becomes after intermediate-freuqncy signal by tuner transition, be sent to channel demodulation module, channel demodulation module is sent to parameter measurements to control and data interface module, control initializes configuration information host computer being sent with data-interface, send channel demodulation module to, make the correctly demodulation of channel demodulation module, control with data-interface and send the measurement data that comprises signal power in parameter measurements to data acquisition module, data acquisition module sends measurement data to host computer, to realize power measurement.This kind of method realizes power measurement by the signal strength signal intensity assessment function of channel demodulation chip, without increasing other assemblies, cost is lower and easy to operate, still, the signal strength signal intensity assessment function of channel demodulation chip can only qualitatively provide the relative size of signal, and can not measure accurately performance number.
Summary of the invention
In view of this, the present invention proposes a kind of accurately method and system of measured signal power, can realize and not increasing under the prerequisite of assembly cost, reach and can accurately measure broadcast television signal, can ensure again the object of portable devices.
The present invention proposes a kind of method of measuring broadcast television signal power, wherein, said method comprising the steps of: step 1: radio and television test receiver receives after signal, tuner sends channel demodulation module and power measurement module to after converting high-frequency signal to intermediate-freuqncy signal; Step 2: by channel demodulation module, the intermediate-freuqncy signal being sent by tuner is carried out to parameter measurement, and measurement result is sent to and controlled and data-interface; Step 3: carry out the DC voltage value of power measurement acquisition as analog level by power measurement module to sent intermediate-freuqncy signal by tuner, and send described analog level to analog-to-digital conversion module; Step 4: analog-to-digital conversion module converts described analog level to digital level, and send control and data-interface to; Step 5: produce tuner by AGC control module and be sent to the voltage of the intermediate-freuqncy signal multiplication factor of power measurement module, and send described voltage to tuner and control and data-interface; Step 6: control with data-interface and send the measurement result of described channel demodulation module, described digital level and described voltage to host computer, described host computer calculates signal power according to described digital level and described potentiometer.
Preferably, described parameter measurement comprises the measurement of modulating mode, chnnel coding efficiency, signal to noise ratio, Packet Error Ratio
Preferably, high-frequency signal is changed into intermediate-freuqncy signal by described tuner, sends channel demodulation module to, the high-frequency signal before unconverted copied to portion simultaneously, changes into intermediate-freuqncy signal, sends power measurement module to.
Preferably, described power measurement module comprises LT5537 power measurement chip.
Preferably, described AGC control module is a digital regulation resistance.
Preferably, described host computer sends instruction, the voltage producing with running parameter and the AGC module of control channel demodulation module.
Preferably, the running parameter of described control channel demodulation module comprises the initializes configuration information of control channel demodulation module, the operating frequency of control channel demodulation module, the modulation parameter of the automatic recall signal of control channel demodulation module or modulation parameter is notified to channel demodulation module.
The invention allows for a kind of system of measuring broadcast television signal power, wherein, described system comprises radio and television test receiver and host computer,
Described radio and television test receiver comprises: tuner sends channel demodulation module and power measurement module to after high-frequency signal being converted to intermediate-freuqncy signal; Channel demodulation module, by the running parameter of channel demodulation module described in PC control, for the intermediate-freuqncy signal being sent by tuner is carried out to parameter measurement, and sends measurement result to control and data-interface to; Power measurement module, for carrying out the DC voltage value of power measurement acquisition as analog level to sent intermediate-freuqncy signal by tuner, and sends described analog level to analog-to-digital conversion module; Analog-to-digital conversion module, for converting the analog level being obtained by described power measurement module to digital level, and sends control and data-interface to; AGC control module, the voltage being produced by AGC control module described in PC control, for regulating tuner to be sent to the voltage of the intermediate-freuqncy signal multiplication factor of power measurement module, and sends described voltage to tuner and control and data-interface; Control and data-interface, the measurement result of described channel demodulation module, described digital level and described voltage are passed to host computer.
Described host computer, for the running parameter of control channel demodulation module and the output voltage of AGC module, the measurement result of receive channel demodulation module, and calculate signal power according to the digital level and the described potentiometer that receive.
Preferably, described parameter measurement comprises the measurement of modulating mode, chnnel coding efficiency, signal to noise ratio, Packet Error Ratio.
Preferably, the running parameter of described control channel demodulation module comprises the initializes configuration information of control channel demodulation module, the operating frequency of control channel demodulation module, the modulation parameter of the automatic recall signal of control channel demodulation module or modulation parameter is notified to channel demodulation module.
Preferably, described tuner comprises the first tuner and second tune device, described the first tuner is for changing into intermediate-freuqncy signal by high-frequency signal, and send channel demodulation module to, the high-frequency signal before unconverted is sent to described second tune device by described the first tuner simultaneously, described second tune device is used for described high-frequency signal to change into intermediate-freuqncy signal, and sends power measurement module to.
Preferably, described power measurement module comprises LT5537 power measurement chip.
Preferably, described AGC control module is a digital regulation resistance.
Embodiment
Describe embodiments of the invention below in detail, the example of described embodiment is shown in the drawings, and wherein same or similar label represents same or similar element or has the element of identical or similar functions from start to finish.Be exemplary below by the embodiment being described with reference to the drawings, only for explaining the present invention, and can not be interpreted as limitation of the present invention.
Referring to Fig. 1, for a kind of method of measuring broadcast television signal power of the present invention's proposition, comprise the following steps: step 1: radio and television test receiver receives after signal, tuner sends channel demodulation module and power measurement module to after converting high-frequency signal to intermediate-freuqncy signal; Step 2: by channel demodulation module, the intermediate-freuqncy signal being sent by tuner is carried out to parameter measurement, and measurement result is sent to and controlled and data-interface; Step 3: carry out the DC voltage value of power measurement acquisition as analog level by power measurement module to sent intermediate-freuqncy signal by tuner, and send described analog level to analog-to-digital conversion module; Step 4: analog-to-digital conversion module converts described analog level to digital level, and send control and data-interface to; Step 5: produce tuner by AGC control module and be sent to the voltage of the intermediate-freuqncy signal multiplication factor of power measurement module, and send described voltage to tuner and control and data-interface; Step 6: control with data-interface and send the measurement result of described channel demodulation module, described digital level and described voltage to host computer, described host computer, by described digital level and described voltage, calculates signal power.
Wherein, described parameter measurement comprises the measurement of modulating mode (for example QPSK modulation, 16QAM modulation), chnnel coding efficiency, signal to noise ratio, Packet Error Ratio (for example LDPC rate of false alarm).
Preferably, high-frequency signal is changed into intermediate-freuqncy signal by described tuner, send channel demodulation module to, high-frequency signal before unconverted is copied to portion simultaneously, change into intermediate-freuqncy signal, send power measurement module to, carry out hoop and go out, the signal that makes to be sent to channel demodulation module and power measurement module is the same, with the measurement of guaranteed output measurement module and the parameter measurement of channel demodulation module for same signal.
Preferably, described power measurement module comprises LT5537 power measurement chip, and measurement result is DC voltage value.
Preferably, described AGC control module is a digital regulation resistance, sends instruction control by host computer, is sent to the voltage of the intermediate-freuqncy signal multiplication factor of power measurement module for generation of tuner.Wherein, multiplication factor refers to that the intermediate-freuqncy signal intensity of tuner output is with respect to the multiplication factor of the high-frequency signal strength of tuner input, because the measuring range of LT5537 power measurement chip is limited, and all in measuring range, the certainty of measurement of some measuring range is the highest, so can send instruction by host computer, allow AGC control module export a voltage, and this voltage is carried out to power measurement, host computer is heightened this voltage or turn down according to measurement result, in the time that the signal of tuner input is very strong, can turn down the output voltage of AGC control module, in the time that the signal of tuner input is very weak, can heighten the output voltage of AGC control module, until AGC control module is exported suitable voltage, can make the intermediate-freuqncy signal of tuner output in the measurable scope of power measurement module.Preferably, AGC control module can be connected to and be controlled and data-interface by 12C bus, host computer sends to the data corresponding magnitude of voltage of needs setting to control and data-interface, then is sent to AGC control module through 12C bus, thereby controls the output voltage of AGC control module.Wherein, controlling with data-interface can be USB controller, ethernet controller, flush bonding processor etc.
In addition, described AGC control module is also sent to host computer by the voltage of described multiplication factor by controlling with data-interface, regulate so that host computer can send instruction according to described voltage, and can according to described voltage and described in the signal power that calculates calculate the signal power of the original high-frequency signal of input tuner.
Preferably, described host computer sends instruction, the running parameter of control channel demodulation module, comprise the initializes configuration information of control channel demodulation module, the operating frequency of control channel demodulation module, the modulation parameter of the automatic recall signal of control channel demodulation module or modulation parameter is notified to channel demodulation module, thus make the correctly demodulation of channel demodulation module.Host computer sends to instruction on equipment by data-interface, can instruction be sent to the USB controller on equipment by USB, then by the 12C bus control channel demodulation module of USB controller, also can pass through RJ45 interface, utilize ethernet controller to carry out control channel demodulation module.
Method of the present invention goes out function by the hoop of tuner, in channel demodulation module surveying work parameter, coordinate power measurement module and analog-to-digital conversion module, accurately measured signal power, do not increasing under the prerequisite of assembly cost to realize, reach and can accurately measure broadcast television signal, can ensure again the object of portable devices.
Referring to Fig. 2, the invention allows for a kind of system of measuring broadcast television signal power, wherein, described system comprises radio and television test receiver 100 and host computer 107, described radio and television test receiver 100 comprises: tuner 101-1,101-2 send channel demodulation module 102 and power measurement module 103 to after high-frequency signal being converted to intermediate-freuqncy signal; Channel demodulation module 102, is controlled the running parameter of described channel demodulation module 102 by host computer 107, for the intermediate-freuqncy signal being sent by tuner 101-1,101-2 is carried out to parameter measurement, and measurement result is sent to and controlled and data-interface 106; Power measurement module 103, for carrying out the DC voltage value of power measurement acquisition as analog level to sent intermediate-freuqncy signal by tuner 101-1,101-2, and sends described analog level to analog-to-digital conversion module 104; Analog-to-digital conversion module 104, for converting the analog level being obtained by described power measurement module 103 to digital level, and sends control and data-interface 106 to; AGC control module 105, control by host computer 107 voltage that described AGC control module 105 produces, for regulating tuner 101-1,101-2 to be sent to the voltage of the intermediate-freuqncy signal multiplication factor of power measurement module 103, and send described voltage to tuner 101-1,101-2 and control and data-interface 106; Control and data-interface 106, send the measurement result of described channel demodulation module 102, described digital level and described voltage to host computer 107; Described host computer 107, for the running parameter of control channel demodulation module 102 and the output voltage of AGC control module 105, the measurement result of receive channel demodulation module 102, digital level and described voltage, and calculate signal power according to described digital level and described potentiometer.
Wherein, described parameter measurement comprises the measurement of modulating mode (for example QPSK modulation, 16QAM modulation), chnnel coding efficiency, signal to noise ratio, Packet Error Ratio (for example LDPC rate of false alarm).
Wherein, the running parameter of described host computer 107 control channel demodulation modules 102, comprise the initializes configuration information of control channel demodulation module 102, the operating frequency of control channel demodulation module 102, the modulation parameter of control channel demodulation module 102 automatic recall signals or modulation parameter is notified to channel demodulation module 102, so that correctly demodulation of channel demodulation module 102.Host computer 107 sends to instruction on equipment by data-interface, can instruction be sent to the USB controller on equipment by USB, then by the 12C bus control channel demodulation module 102 of USB controller, also can pass through RJ45 interface, utilize ethernet controller to carry out control channel demodulation module 102.
Preferably, described tuner comprises the first tuner 101-1 and second tune device 101-2, described the first tuner 101-1 is for changing into intermediate-freuqncy signal by high-frequency signal, and send channel demodulation module 102 to, the high-frequency signal before unconverted is sent to described second tune device 101-2 by described the first tuner 101-1 simultaneously, described second tune device 101-2 is used for described high-frequency signal to change into intermediate-freuqncy signal, and sends power measurement module 103 to, carries out hoop and goes out; Go out to the hoop between second tune device 101-2 by the first tuner 101-1, it is the same making the signal of the first tuner 101-1 and second tune device 101-2 input, with the measurement of guaranteed output measurement module 103 and the parameter measurement of channel demodulation module 102 for same signal.
Preferably, described power measurement module 103 comprises LT5537 power measurement chip, and measurement result is DC voltage value.
Preferably, described AGC control module 105 is a digital regulation resistance, sending instruction by host computer 107 controls, be sent to the voltage of the intermediate-freuqncy signal multiplication factor of power measurement module 103 for generation of second tune device 101-2, wherein, multiplication factor refers to that the intermediate-freuqncy signal intensity of second tune device 101-2 output is with respect to the multiplication factor of the high-frequency signal strength of second tune device 101-2 input, because the measuring range of LT5537 power measurement chip is limited, and all in measuring range, the certainty of measurement of some measuring range is the highest, so can send instruction by host computer 107, allow AGC control module 105 export a voltage, and this voltage is carried out to power measurement, host computer 107 is heightened this voltage or turn down according to measurement result, in the time that the signal of second tune device 101-2 input is very strong, can turn down the output voltage of AGC control module 105, when the signal inputted when second tune device 105 is very weak, can heighten the output voltage of AGC control module 105, until AGC control module 105 is exported suitable voltage, can make the intermediate-freuqncy signal of second tune device 101-2 output in the measurable scope of power measurement module 103.Preferably, AGC control module 105 can be connected to and be controlled and data-interface 106 by 12C bus, host computer 107 sends to the data corresponding magnitude of voltage of needs setting to control and data-interface 106, be sent to AGC control module 105 through 12C bus again, thereby control the output voltage of AGC control module 105.Wherein, controlling with data-interface 106 can be USB controller, ethernet controller, flush bonding processor etc.
In addition, described AGC control module 105 is also sent to host computer 107 by the voltage of described multiplication factor by controlling with data-interface 106, regulate so that host computer 107 can send instruction according to described voltage, and can according to described voltage and described in the signal power that calculates calculate the signal power of the original high-frequency signal of input tuner.
System of the present invention goes out function by the hoop of tuner, in channel demodulation module surveying work parameter, coordinate power measurement module and analog-to-digital conversion module, accurately measured signal power, do not increasing under the prerequisite of assembly cost to realize, reach and can accurately measure broadcast television signal, can ensure again the object of portable devices.
The above is only the preferred embodiment of the present invention; it should be pointed out that for those skilled in the art, under the premise without departing from the principles of the invention; can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.