CN203180921U - System for detecting communication performance of low-voltage OFDM carrier wave physical layer - Google Patents
System for detecting communication performance of low-voltage OFDM carrier wave physical layer Download PDFInfo
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- CN203180921U CN203180921U CN2013201656150U CN201320165615U CN203180921U CN 203180921 U CN203180921 U CN 203180921U CN 2013201656150 U CN2013201656150 U CN 2013201656150U CN 201320165615 U CN201320165615 U CN 201320165615U CN 203180921 U CN203180921 U CN 203180921U
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Abstract
The utility model discloses a system for detecting communication performance of a low-voltage OFDM carrier wave physical layer, the system being used for detecting the emission performance index and the receiving performance index of the low-voltage OFDM carrier wave physical layer. The system comprises a signal isolation device, a standard carrier wave transmission device, a transmission device for carrier waves to be detected, a receiving device for the carrier waves to be detected, a standard 50 ohms impedance power supply network, a coupling circuit, two mixers, two adjustable attenuators, a Gauss white noise generator, a line impedance stabilization network, a PLC demodulation device, an AC power meter, a 220V AC power supply, a signal generator, a network analyzer, a frequency spectrum analyzer, a channel simulation instrument, a signal analyzer and a computer. Based on the technical features of the low-voltage electrical line carrier wave communication of an OFDM modulation mode, a precise detection may be carried out in terms of major performance index of the aforementioned communication method, and the detection procedures are quite convenient. Besides, the system also has the advantages of high system integration, low system cost, less occupied space and low labor cost.
Description
Technical field
The utility model relates to the power line carrier communication field, relates in particular to a kind of low pressure OFDM carrier wave physical layer communication performance detecting system.
Background technology
At present, still there is not special detection system for the detection based on the low-voltage powerline carrier communication mode of OFDM modulation system, employed testing equipment over-borrowing is built with Wireless Telecom Equipment, both caused the waste of testing equipment, reduce testing efficiency again, can't test all performance index fully.
The utility model content
The purpose of this utility model is in order to overcome the above-mentioned problems in the prior art, a kind of low pressure OFDM carrier wave physical layer communication performance detecting system to be provided, and is low and can not test the problem of all properties index fully to solve present checkout equipment testing efficiency.
In order to achieve the above object, the utility model embodiment discloses a kind of low pressure OFDM carrier wave physical layer communication performance detecting system, for detection of emitting performance index and the receptivity index of low pressure OFDM carrier wave physical layer, it comprises: isolation signals equipment, the standard carrier transmitting apparatus, carrier wave transmitting apparatus to be measured, carrier wave receiving equipment to be measured, standard 50 Ω impedance electric power networks, coupling circuit, two blenders, two adjustable attenuators, Gaussian white noise generator, line impedance stabilization net work, the PLC demodulated equipment, the AC power meter, the 220V AC power, signal generator, network analyzer, spectrum analyzer, the channel simulation instrument, signal analyzer and computer; Wherein, described isolation signals equipment, standard carrier transmitting apparatus, carrier wave transmitting apparatus to be measured, carrier wave receiving equipment to be measured, standard 50 Ω impedance electric power networks are connected to outside electricity network; Described carrier wave transmitting apparatus to be measured and described carrier wave receiving equipment to be measured are connected to a bus by serial ports, described coupling circuit, Gaussian white noise generator, line impedance stabilization net work, PLC demodulated equipment, signal generator, network analyzer, spectrum analyzer, channel simulation instrument and signal analyzer are connected to described bus, and described PLC demodulated equipment is connected to described computer by serial ports; Described two blenders are arranged in described detection system, when using, it are inserted test circuit, can mix and along separate routes signal, and will through mixing and along separate routes after signal send described computer to by serial ports and carry out the data processing; Described two adjustable attenuators are arranged in described detection system, when using, it is inserted test circuit, for detection of the performance of the anti-white Gaussian noise of low pressure OFDM carrier communication system, when carrying out this detection, described two adjustable attenuators are linked in the described bus.
Further, described emitting performance index comprises: OFDM reference carrier frequency, OFDM frequency bandwidth, OFDM carrier frequency stability, logic time domain specification, the test of range error vector, harmonic wave and clutter test, power output accuracy, symbol be error, transmitter modulation accuracy, crest factor, overall efficiency all the time.
Further, described receptivity index comprises: signal receiving sensitivity, transmission data consistency, bit error rate, frame error rate, received signal quality consistency, receive frequency range, reflection loss, suppressor pulse interference performance, suppress with frequently, face frequently interference performance, suppress 0db echo ability, suppress carrier-to-noise ratio thresholding, anti-phase noise ability under multipath ability, the Gaussian channel.
Further, when detecting described OFDM reference carrier frequency index, utilize described signal xegregating unit, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit and frequency analyzer to realize; Described carrier transmit equipment output measured signal to be measured becomes the light current high-frequency signal by described coupling circuit, is transferred to described frequency analyzer and carries out spectrum analysis; Described signal xegregating unit is used for isolating the High-frequency Interference on the electricity network; Described standard 50 Ω impedance electric power networks are used for the test circuit impedance stabilization about 50 Ω.
Further, when detecting described OFDM frequency bandwidth index, utilize described signal xegregating unit, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit and frequency analyzer to realize; The signal amplitude of the measured signal that described carrier wave transmitting apparatus to be measured is sent is transferred to the maximum of indicating in the equipment service manual, carry out spectrum analysis by described frequency analyzer, described frequency bandwidth is all hanging down 20dB with interior siding-to-siding block length than frequency amplitude maximum for analyzing all frequency amplitudes that obtain.
Further, when detecting described logic time domain specification index, utilize described signal xegregating unit, standard carrier transmitting apparatus, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit and frequency analyzer to realize; By transmitting time between described carrier wave transmitting apparatus to be measured and the described standard carrier transmitting apparatus to recently whether decision logic passage time domain specification qualified.
Further, when detecting described range error vector index, utilize described standard carrier transmitting apparatus, carrier wave transmitting apparatus to be measured and signal analyzer to realize; The signal that described carrier wave transmitting apparatus to be measured and described standard carrier transmitting apparatus are sent transfers to described signal analyzer, carries out the amplitude vector error comparative analysis of signal.
Further, when detecting described power output accuracy index, utilize described signal xegregating unit, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit, frequency analyzer and computer to realize; The signal that described carrier wave transmitting apparatus to be measured is sent is transferred to described frequency analyzer, directly power data is transferred to computer read-out power value size by described frequency analyzer.
Further, when detecting described symbol clock error criterion, utilize described signal xegregating unit, standard carrier transmitting apparatus, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit and frequency analyzer to realize; By the transmitting time between described carrier wave transmitting apparatus to be measured and the described standard carrier transmitting apparatus to recently obtaining described symbol clock error.
Further, when detecting described crest factor index, utilize described signal xegregating unit, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit and frequency analyzer to realize; Obtain the peak value of the signal that described carrier wave transmitting apparatus to be measured sends and the ratio of root-mean-square value by described frequency analyzer, be described crest factor.
Further, when detecting described overall efficiency index, utilize described signal xegregating unit, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit, frequency analyzer, computer and 220V AC power and AC power meter to realize; Described carrier transmit equipment output measured signal to be measured becomes the light current high-frequency signal by described coupling circuit, is transferred to described frequency analyzer and carries out spectrum analysis; Described AC power meter is used for the power loss of described carrier wave transmitting apparatus to be measured is measured; Described signal xegregating unit is used for isolating the High-frequency Interference on the electricity network; Described standard 50 Ω impedance electric power networks are used for the test circuit impedance stabilization about 50 Ω.
Further, when detecting described signal receiving sensitivity index, utilize described signal xegregating unit, carrier wave transmitting apparatus to be measured, carrier wave receiving equipment to be measured, line impedance stabilization net work, coupling circuit and channel simulation instrument, signal analyzer to realize; Described carrier transmit equipment to be measured is connected on the described electricity network by described line impedance stabilization net work and signal xegregating unit, and send communication message continuously, described communication message sends to described signal analyzer, carries out first frequency conversion and AD conversion back and stores in the mode of digital signal; Described carrier wave receiving equipment to be measured receives the digital signal after the described storage, utilize described channel simulation instrument to change power output, constantly make described digital signal decay, take defeat up to described signal analyzer demonstration, the power output of this moment is the receiving sensitivity of described carrier wave receiving equipment to be measured.
Further, when detecting described transmission data consistency index, utilize described signal xegregating unit, standard carrier transmitting apparatus, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, PLC demodulated equipment and computer to realize; Described PLC demodulated equipment carries out demodulation respectively with the signal that described standard carrier transmitting apparatus and carrier wave transmitting apparatus to be measured send, but coding is conciliate in not deinterleaving, the signal after the described demodulation is sent to described computer carry out the data comparative analysis.
Further, when detecting described bit error rate index, utilize described signal xegregating unit, carrier wave receiving equipment to be measured, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks and computer to realize; Described carrier wave receiving equipment to be measured, carrier wave transmitting apparatus to be measured are connected to described computer respectively by serial ports, described carrier wave transmitting apparatus to be measured sends a signal to described carrier wave receiving equipment to be measured, and send described computer simultaneously to, after described computer received the signal that described carrier wave receiving equipment to be measured transmits, the signal that itself and described measured signal transmitting apparatus are transmitted carried out the contrast of bit error rate; Described signal xegregating unit is used for isolating the High-frequency Interference on the electricity network; Described standard 50 Ω impedance electric power networks are used for the test circuit impedance stabilization about 50 Ω.
Further, when detecting described received signal quality coincident indicator, utilize described signal xegregating unit, carrier wave receiving equipment to be measured, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit, signal generator and computer to realize; Described carrier wave receiving equipment to be measured, carrier wave transmitting apparatus to be measured are connected to described computer respectively by serial ports, described carrier wave transmitting apparatus to be measured sends a signal to described carrier wave receiving equipment to be measured, and send described computer simultaneously to, described signal generator is connected to described computer by described coupling circuit, in channel, inject the noise signal that presets, the signal that the signal that the carrier wave receiving equipment described to be measured that described computer reception has added noise transmits and described measured signal transmitting apparatus transmit carries out both the contrast of bit error rate; Described signal xegregating unit is used for isolating the High-frequency Interference on the electricity network; Described standard 50 Ω impedance electric power networks are used for the test circuit impedance stabilization about 50 Ω.
Further, when detecting described receive frequency range index, utilize one in described signal xegregating unit, carrier wave receiving equipment to be measured, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit, frequency analyzer, computer and two blenders to realize; Utilize described carrier wave transmitting apparatus to be measured, send the carrier signal of different frequency point, by behind the described blender signal being divided into two-way, one road signal is transferred to described frequency analyzer through described coupling circuit, through measuring the accurate frequency values that transmits, another road signal is transferred to described carrier wave receiving equipment to be measured; Described carrier wave receiving equipment to be measured, carrier wave transmitting apparatus to be measured are connected to described computer respectively by serial ports, described carrier wave receiving equipment to be measured receives the carrier signal of being sent by described carrier wave transmitting apparatus to be measured, and send described computer simultaneously to, whether correctly received by described computer-made decision; Described signal xegregating unit is used for isolating the High-frequency Interference on the electricity network; Described standard 50 Ω impedance electric power networks are used for the test circuit impedance stabilization about 50 Ω.
Further, when detecting described suppressor pulse interference performance index, utilize one in described signal xegregating unit, carrier wave receiving equipment to be measured, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit, signal generator, computer and two blenders to realize; Utilize described carrier wave transmitting apparatus to be measured, send carrier signal, as first via measured signal; By described signal generator production burst interference signal, as the second tunnel measured signal, by described blender two paths of signals is synthesized one road signal simultaneously, be transferred to described carrier wave receiving equipment to be measured.Described carrier wave receiving equipment to be measured, carrier wave transmitting apparatus to be measured are connected to described computer respectively by serial ports, described carrier wave receiving equipment to be measured receives the test carrier signal of being sent by carrier wave transmitting apparatus to be measured, and send described computer simultaneously to, whether correctly received by described computer-made decision; Described signal xegregating unit is used for isolating the High-frequency Interference on the electricity network; Described standard 50 Ω impedance electric power networks are used for the test circuit impedance stabilization about 50 Ω.
Further, detecting described inhibition with frequently, when facing frequency interference performance index, described low pressure OFDM carrier wave physical layer communication performance detecting system further comprises one second carrier wave transmitting apparatus to be measured; Utilize one of described signal xegregating unit, carrier wave receiving equipment to be measured, two carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks and two blenders to realize.
Further, detect described 0db clawback ability, when suppressing multipath ability index, utilizing one of described signal xegregating unit, carrier wave receiving equipment to be measured, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, signal imitation instrument, Gaussian white noise generator and two blenders to realize.
Further, during carrier-to-noise ratio thresholding index under detecting described Gaussian channel, utilize described signal xegregating unit, carrier wave receiving equipment to be measured, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit, frequency analyzer, two adjustable attenuators, signal imitation instrument, Gaussian white noise generator and two blenders to realize.
Further, when detecting described anti-phase noise ability index, described low pressure OFDM carrier wave physical layer communication performance detecting system further comprises one second Gaussian white noise generator, utilizes described signal xegregating unit, carrier wave receiving equipment to be measured, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit, PLC demodulated equipment, frequency analyzer, two adjustable attenuators, signal generator, Gaussian white noise generator, second Gaussian white noise generator and two blenders to realize.
The low pressure OFDM carrier wave physical layer communication performance detecting system of the utility model embodiment, specially at the technical characterstic of the low-voltage powerline carrier communication of OFDM modulation system, can carry out DCO to the main performance index of this communication mode, testing process is convenient, system combination is strong, system cost is low, saves space and human cost.
Description of drawings
In order to be illustrated more clearly in the utility model embodiment or technical scheme of the prior art, to do to introduce simply to the accompanying drawing of required use in embodiment or the description of the Prior Art below, apparently, accompanying drawing in describing below only is embodiment more of the present utility model, for those skilled in the art, under the prerequisite of not paying creative work, can also obtain other accompanying drawing according to these accompanying drawings.
Fig. 1 is the structural representation of the low pressure OFDM carrier wave physical layer communication performance detecting system of the utility model embodiment;
Fig. 2 utilizes low pressure OFDM carrier wave physical layer communication performance detecting system shown in Figure 1 to carry out the test structure figure that OFDM reference carrier frequency index detects;
Fig. 3 is the schematic diagram that utilizes OFDM frequency bandwidth that low pressure OFDM carrier wave physical layer communication performance detecting system shown in Figure 1 carries out to measure;
Fig. 4 utilizes low pressure OFDM carrier wave physical layer communication performance detecting system shown in Figure 1 to carry out the test structure figure that logic time domain specification index detects;
Fig. 5 utilizes low pressure OFDM carrier wave physical layer communication performance detecting system shown in Figure 1 to carry out the test structure figure that range error vector index detects;
Fig. 6 utilizes low pressure OFDM carrier wave physical layer communication performance detecting system shown in Figure 1 to carry out the test structure figure that power output accuracy index detects;
Fig. 7 utilizes low pressure OFDM carrier wave physical layer communication performance detecting system shown in Figure 1 to carry out the test structure figure that the crest factor index detects;
Fig. 8 utilizes low pressure OFDM carrier wave physical layer communication performance detecting system shown in Figure 1 to carry out the test structure figure that the overall efficiency index detects;
Fig. 9 utilizes low pressure OFDM carrier wave physical layer communication performance detecting system shown in Figure 1 to carry out the test structure figure that transmit record of signal receiving sensitivity index in detecting;
Figure 10 utilizes low pressure OFDM carrier wave physical layer communication performance detecting system shown in Figure 1 to carry out the test structure figure of the receiving sensitivity test in the detection of signal receiving sensitivity index;
Figure 11 utilizes low pressure OFDM carrier wave physical layer communication performance detecting system shown in Figure 1 to transmit the test structure figure that the data consistency index detects;
Figure 12 utilizes low pressure OFDM carrier wave physical layer communication performance detecting system shown in Figure 1 to carry out the test structure figure that the bit error rate index detects;
Figure 13 utilizes low pressure OFDM carrier wave physical layer communication performance detecting system shown in Figure 1 to carry out the test structure figure that the received signal quality coincident indicator detects;
Figure 14 utilizes low pressure OFDM carrier wave physical layer communication performance detecting system shown in Figure 1 to carry out the test structure figure that the receive frequency range index detects;
Figure 15 utilizes low pressure OFDM carrier wave physical layer communication performance detecting system shown in Figure 1 to carry out the test structure figure that the launch loss index detects;
Figure 16 utilizes low pressure OFDM carrier wave physical layer communication performance detecting system shown in Figure 1 to carry out the test structure figure that suppressor pulse interference performance index detects;
Figure 17 utilizes low pressure OFDM carrier wave physical layer communication performance detecting system shown in Figure 1 to suppress with frequency, face the test structure figure of interference performance index detection frequently;
Figure 18 utilizes low pressure OFDM carrier wave physical layer communication performance detecting system shown in Figure 1 to suppress the test structure figure of 0db echo ability, the detection of inhibition multipath ability index;
Figure 19 utilizes low pressure OFDM carrier wave physical layer communication performance detecting system shown in Figure 1 to carry out the test structure figure that the carrier-to-noise ratio thresholding index under the Gaussian channel detects;
Figure 20 utilizes low pressure OFDM carrier wave physical layer communication performance detecting system shown in Figure 1 to carry out the test structure figure that anti-phase noise ability index detects.
Embodiment
Below in conjunction with the accompanying drawing among the utility model embodiment, the technical scheme among the utility model embodiment is clearly and completely described, obviously, described embodiment only is the utility model part embodiment, rather than whole embodiment.Based on the embodiment in the utility model, those of ordinary skills are not making the every other embodiment that obtains under the creative work prerequisite, all belong to the scope of the utility model protection.
In the utility model embodiment, low pressure OFDM carrier wave physical layer communication performance detecting system is that the key instrument that needs use is placed in the big rack, for the convenient of test macro uses, all appts is connected on same the bus, utilize bus when testing different indexs, signal to be imported in the different instruments, also have two blenders in the bus, can mix and shunt signal, data can be passed to computer by serial ports simultaneously and carry out the data processing.Also adjustable attenuator can be inserted in the bus according to the test needs, for detection of the performance of the anti-white Gaussian noise of low pressure OFDM carrier communication system.
Fig. 1 is the structural representation of the low pressure OFDM carrier wave physical layer communication performance detecting system of the utility model embodiment.As shown in Figure 1, the low pressure OFDM carrier wave physical layer communication performance detecting system of present embodiment comprises: isolation signals equipment, standard carrier transmitting apparatus, carrier wave transmitting apparatus to be measured, carrier wave receiving equipment to be measured, standard 50 Ω impedance electric power networks, coupling circuit, two blenders, two adjustable attenuators, Gaussian white noise generator, line impedance stabilization net work, PLC demodulated equipment, AC power meter, 220V AC power, signal generator, network analyzer, spectrum analyzer, channel simulation instrument, signal analyzer and computers;
Wherein, described isolation signals equipment, standard carrier transmitting apparatus, carrier wave transmitting apparatus to be measured, carrier wave receiving equipment to be measured, standard 50 Ω impedance electric power networks are connected to outside electricity network; Described carrier wave transmitting apparatus to be measured and described carrier wave receiving equipment to be measured are connected to a bus by serial ports, described coupling circuit, Gaussian white noise generator, line impedance stabilization net work, PLC demodulated equipment, signal generator, network analyzer, spectrum analyzer, channel simulation instrument and signal analyzer are connected to described bus, and described PLC demodulated equipment is connected to described computer by serial ports; Described two blenders can mix and along separate routes signal, and will through mixing and along separate routes after signal send described computer to by serial ports and carry out the data processing; Described two adjustable attenuators, are linked into described two adjustable attenuators in the described bus when carrying out this detection for detection of the performance of the anti-white Gaussian noise of low pressure OFDM carrier communication system.
Below introduce groundwork principle and step that low pressure OFDM carrier wave physical layer communication performance detecting system of the present utility model carries out emitting performance index and the detection of receptivity index respectively.
1) OFDM reference carrier frequency
Fig. 2 utilizes low pressure OFDM carrier wave physical layer communication performance detecting system shown in Figure 1 to carry out the test structure figure that OFDM reference carrier frequency index detects.
Because the OFDM modulation system does not have centre frequency, frequency range has big difference between the process if transmit and receive in devices from different manufacturers, can influence the characteristic that interconnects of system, so stipulate certain frequency departure scope, make the transmitter frequency of each manufacturer production all within deviation, conveniently receive.Test system structure block diagram as shown in Figure 2 utilizes described signal xegregating unit, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit and frequency analyzer to realize; Described carrier transmit equipment output measured signal to be measured becomes the light current high-frequency signal by described coupling circuit, is transferred to described frequency analyzer and carries out spectrum analysis; Described signal xegregating unit is used for isolating the High-frequency Interference on the electricity network; Described standard 50 Ω impedance electric power networks are used for the test circuit impedance stabilization about 50 Ω.
2) OFDM frequency bandwidth
During test, the signal amplitude of carrier wave transmitting apparatus to be measured is transferred to the maximum of indicating in the equipment service manual, use spectrum analyzer that signal is detected, the width of frequency spectrum (representing with Hz) is defined as interval all interior frequency amplitudes and is all hanging down 20dB with interior siding-to-siding block length than frequency amplitude maximum.As shown in Figure 3.Wherein, frequency analyzer has peak detection function, as NI PCI-5114.
3) OFDM carrier frequency stability
Because the frequency deviation of OFDM is comparatively responsive, less frequency deviation just may cause communication quality to descend, in order to guarantee the stability of the low pressure OFDM carrier wave that transmitter sends, need carry out standard to the frequency stability of OFDM subcarrier, avoid in communication process the OFDM sub-carrier frequencies to occur than great fluctuation process.
For single-phase equipment, measurement must guarantee to carry out in certain phase place or neutral the connection; For three-phase equipment, if only send with single-phase, measurement must guarantee to carry out in certain phase place or neutral the connection, if send simultaneously on three phase places, three phase places must be measured.
4) logic time domain specification
The time domain specification of logical channel is the important indicator of carrier wave physical layer communication, logical channel is at transmitting time, time of reception, sent conversion between state and the accepting state and be the important step in the communication, so need test the time domain specification of logical channel, by transmitting time between equipment to be tested and the standard device to recently whether decision logic passage time domain specification qualified.
Fig. 4 utilizes low pressure OFDM carrier wave physical layer communication performance detecting system shown in Figure 1 to carry out the test structure figure that logic time domain specification index detects.As shown in the figure, when detecting described logic time domain specification index, utilize described signal xegregating unit, standard carrier transmitting apparatus, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit and frequency analyzer to realize; By transmitting time between described carrier wave transmitting apparatus to be measured and the described standard carrier transmitting apparatus to recently whether decision logic passage time domain specification qualified.
In the present embodiment, frequency analyzer adopts the digitizer PCI-5114 of NI company, and this frequency analyzer has the 125MHz bandwidth, can satisfy the bandwidth requirement of wideband OFDM fully.
Signal becomes the light current high-frequency signal from standard carrier transmit equipment to be measured and carrier transmit equipment to be measured output by coupling circuit, is transferred to PCI5114, and the carrier signal of two cover transmitter outputs is carried out the comparative analysis of logic time domain specification.The signal xegregating unit is responsible for isolating the High-frequency Interference on the electricity network; 50ohm impedance electric power network is responsible for the test circuit impedance stabilization about 50ohm.
5) range error vector (EVM) test
The range error vector is the vector difference in the desirable error free signal of a given time and actual transmit signal.Can be mutually orthogonal I component and Q component with signal decomposition, in I/Q figure, ideal signal and actual signal be nonoverlapping often, and the difference between two vectors is EVM.
EVM uses following formula and calculates:
The test of range error vector is to utilize a vector signal generator to produce a vector signal, analyze the modulation signal that generator sends with a VSA again, be I component and Q component with signal decomposition, ideal I component and Q component with the signal of setting compares again, draw the amplitude vector error, the system block diagram of test as shown in Figure 5, when detecting described range error vector index, utilize described standard carrier transmitting apparatus, carrier wave transmitting apparatus to be measured and signal analyzer to realize;
The signal that described carrier wave transmitting apparatus to be measured and described standard carrier transmitting apparatus are sent transfers to described signal analyzer, carries out the amplitude vector error comparative analysis of signal.
6) harmonic wave and clutter test
Transmitter output signal is generally high-power signal, produces higher harmonic wave and clutter outside the frequency band that can transmit in the process that produces high-power signal.Interior amplitude is higher if these harmonic waves and clutter fall into the reception frequency range of receiver, then can cause the input signal-to-noise ratio of receiving system to reduce, and communication quality worsens.So need the performance of harmonic wave and the clutter of test receiver.
Test structure adopts the test structure of Fig. 2, needs to measure signal power, the signal power of local oscillator nth harmonic and the highest signal power of other amplitude except the local oscillator harmonic wave of local oscillation signal.
7) power output accuracy
Power output is under the distortionless prerequisite of transmitter output signal, the maximum of the power output that can work long hours.The accuracy of standard power output make the equipment that different manufacturers is produced power output within the specific limits, guarantee the interconnecting property of communication.The power measurement of signal partly adopts frequency analyzer PCI-5114, directly power data is transferred to computer, by computer software read-out power value size.Test structure figure such as Fig. 6 of power output test utilize described signal xegregating unit, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit, frequency analyzer and computer to realize; The signal that described carrier wave transmitting apparatus to be measured is sent is transferred to described frequency analyzer, directly power data is transferred to computer read-out power value size by described frequency analyzer.
Be under the situation of 50 Ω inserting impedance, the average power of all subcarriers is with respect to the quantity of total power divided by subcarrier, and error should not surpass+/-2dB.
8) symbol clock error
The symbol clock error refers to poor with respect to the reference symbol clock of the reference symbol clock of system sampling clock and actual measurement.The if symbol clock than desired length, causes that sub-carrier separation reduces than the low ofdm signal that can make of reference clock; Otherwise, cause that then sub-carrier separation increases.Either way produce inter-carrier interference, make the EVM mis-behave of signal.
The test macro block diagram utilizes described signal xegregating unit, standard carrier transmitting apparatus, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit and frequency analyzer to realize as shown in Figure 4; By the transmitting time between described carrier wave transmitting apparatus to be measured and the described standard carrier transmitting apparatus to recently obtaining described symbol clock error.The frequency and the used clock of symbol that send signal in the transmitting apparatus should derive from same system clock.
9) transmitter modulation accuracy
According to ITU-T draft standard G.9955, need under 400K per second sampled point or higher sample rate condition, carry out the sample rate conversion of data flow the test of transmitter modulation accuracy, main content measurement is signal amplitude, the accuracy of direct current biasing and phase noise.The mode that is sampled the signal processing is similar to actual receiver.
The step plan of test is carried out according to the following steps, or takes mode of equal value:
A) complete 1 symbol of generation some, represent a frame of transmitter specified modulation mode, be example with 12 symbol QPSK, by a sub-transmitter of desirable floating type (for example using matlab emulation), again the input of complex IFFT preserved into A by per 12 data symbols
IcExp[j Φ
Ic] form (i conventional letter, c represent the subcarrier of this symbol), desirable sub-transmitter should possess all functions of transmitter, scrambler for example, forward error correction interweaves and shines upon.
B) use the transmitter of tape test to produce an identical frame according to the symbol in the previous step.
C) testing equipment with simulated receiver is directly connected on the transmitter, detects the original position of frame.
D) all 12 symbol datas of preservation frame.
E) disconnect connection, carry out FFT to received signal, each symbol complex values is saved as B
IcExp[j θ
Ic] form (i conventional letter, c represent the subcarrier of this symbol).
F) calculate the symbol of tested transmitter and the error vector between the desirable transmitter symbol, and ask mean-square value, obtain the signal accuracy of tested transmitter emission.
10) crest factor
Crest factor is the ratio of peak value and root-mean-square value, is the instrument of weighing the mean-square value dynamic range.Measurement employing measurement structure chart as shown in Figure 7 to crest factor utilizes described signal xegregating unit, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit and frequency analyzer to realize; Obtain the peak value of the signal that described carrier wave transmitting apparatus to be measured sends and the ratio of root-mean-square value by described frequency analyzer, be described crest factor.
11) overall efficiency
The overall efficiency of transmitter is the ratio of transmitting power in the band with AC power power meter power.The system block diagram of test receiver overall efficiency utilizes described signal xegregating unit, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit, frequency analyzer, computer and 220V AC power and AC power meter to realize as shown in Figure 8;
Described carrier transmit equipment output measured signal to be measured becomes the light current high-frequency signal by described coupling circuit, is transferred to described frequency analyzer and carries out spectrum analysis; Described AC power meter is used for the power loss of described carrier wave transmitting apparatus to be measured is measured; Transmitter to be measured is powered separately by the 220V AC power, during the incoming transport electrodymamometer, the power loss of transmitter is measured.Described signal xegregating unit is used for isolating the High-frequency Interference on the electricity network; Described standard 50 Ω impedance electric power networks are used for the test circuit impedance stabilization about 50 Ω.
12) signal receiving sensitivity
In low pressure OFDM carrier wave physical layer transmission process, signal can in order to guarantee the successful communication rate, need test and the receptible minimum signal of standard receiver, the just receiving sensitivity of receiver owing to a variety of causes causes decay.The test of receiving sensitivity is divided into transmitting records and receiving sensitivity test two parts, wherein transmit and record test circuit johning knot composition partly as shown in Figure 9, described carrier transmit equipment to be measured is connected on the described electricity network by described line impedance stabilization net work and signal xegregating unit, and sending communication message continuously, the MPW201 circuit that the line impedance stabilization net work among the figure partly adopts Japanese MICRONIX company to produce is stablized impedance network and is tested.Described communication message sends to described signal analyzer, carries out first frequency conversion and AD conversion back and stores in the mode of digital signal;
Figure 10 is the system construction drawing of receiving sensitivity test, in the receiving sensitivity test, described carrier wave receiving equipment to be measured receives the digital signal after the described storage, utilize described channel simulation instrument to change power output, constantly make described digital signal decay, take defeat up to described signal analyzer demonstration, the power output of this moment is the receiving sensitivity of described carrier wave receiving equipment to be measured.
13) transmission data consistency
In order to guarantee that same receiving equipment can receive the signal by the carrier equipment emission of different manufacturers, needs the data of transmission to have consistency.In this test, the method of testing that adopts is under the communication condition that does not apply noise, the carrier equipment of different manufacturers is with the identical identical data of mode of operation transmission, compare at receiver one end, if mode unanimities such as the interweaving of carrier equipment, codings, the data flow that then draws should be consistent.Test condition is to allow carrier equipment to allow to send the transmission that the maximum level standard is carried out greatest physical layer data load, and detect and will cover all mode of operations (BPSK/QPSK/Enhance), the data length of test will be supported the data load of physical layer transmission one frame maximum.The system configuration frame of test utilizes described signal xegregating unit, standard carrier transmitting apparatus, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, PLC demodulated equipment and computer to realize as shown in figure 11; Described PLC demodulated equipment carries out demodulation respectively with the signal that described standard carrier transmitting apparatus and carrier wave transmitting apparatus to be measured send, but coding is conciliate in not deinterleaving, the signal after the described demodulation is sent to described computer carry out the data comparative analysis.
Data are imported the processing section behind the computer into, and the utility model will utilize labview to write testing software specially and calculate every index.
14) bit error rate (BER)
Bit error rate is the ratio of error of transmission bit number and total transmitted bit number, by detecting the reliability that bit error rate can be tested each producer's carrier equipment.Data when the data when the test bit error rate utilizes the carrier wave transmitting apparatus to send and receiver receive compare to obtain BER.The test macro block diagram utilizes described signal xegregating unit, carrier wave receiving equipment to be measured, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks and computer to realize as shown in figure 12;
Described carrier wave receiving equipment to be measured, carrier wave transmitting apparatus to be measured are connected to described computer respectively by serial ports, described carrier wave transmitting apparatus to be measured sends a signal to described carrier wave receiving equipment to be measured, and send described computer simultaneously to, after described computer received the signal that described carrier wave receiving equipment to be measured transmits, the signal that itself and described measured signal transmitting apparatus are transmitted carried out the contrast of bit error rate; Carrier transmit equipment to be measured is powered separately by the 220V AC power, during the incoming transport electrodymamometer, the power loss of transmitter is measured.Described signal xegregating unit is used for isolating the High-frequency Interference on the electricity network; Described standard 50 Ω impedance electric power networks are used for the test circuit impedance stabilization about 50 Ω.
Standard carrier equipment should carry out the transmission 2000 times of greatest physical layer data load allow to send the maximum level standard, and BER should be greater than 10-6, and different working modes should be added up respectively.
15) frame error rate (FER)
When having dislocation in frame of indication in the Error detection function of receiver, this frame just is defined as the frame of makeing mistakes, and frame error rate is the ratio of frame number and total transmission frame number of makeing mistakes.The stability that the test frame error rate can detected carrier equipment transmits.The system configuration that detects frame error rate also adopts the structure of Figure 12.
Identical with error rate test, in the frame error rate test, the carrier wave transmitting apparatus should carry out the transmission 2000 times that the greatest physical layer data meets to allow to send the maximum level standard, and frame error rate should be greater than 0.2%, and different working modes should be added up respectively.
16) received signal quality consistency
In communication process, judge that the most frequently used index of received signal quality is signal to noise ratio, this parameter upper strata transistroute is often selected important evidence.Identical transmit and noise conditions under, different carrier equipments receives signals must be in certain deviation range, the received signal quality consistency has determined the overall performance of system.
During test received signal quality consistency, carrier equipment is to allow to send the transmission that the maximum level standard is carried out greatest physical layer data load, and applying the white Gaussian noise of different gains to channel, the standard receiving equipment receives difference between the signal to noise ratio of signal and requires in deviation range necessarily under the signal to noise ratio that receiver device to be measured receives signal and the same case.
Figure 13 is the system construction drawing of received signal quality uniformity test, as shown in the figure, utilize described signal xegregating unit, carrier wave receiving equipment to be measured, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit, signal generator and computer to realize;
Described carrier wave receiving equipment to be measured, carrier wave transmitting apparatus to be measured are connected to described computer respectively by serial ports, described carrier wave transmitting apparatus to be measured sends a signal to described carrier wave receiving equipment to be measured, and send described computer simultaneously to, described signal generator is connected to described computer by described coupling circuit, in channel, inject the noise signal that presets, the signal that the signal that the carrier wave receiving equipment described to be measured that described computer reception has added noise transmits and described measured signal transmitting apparatus transmit carries out both the contrast of bit error rate; Described signal xegregating unit is used for isolating the High-frequency Interference on the electricity network; Described standard 50 Ω impedance electric power networks are used for the test circuit impedance stabilization about 50 Ω.
17) receive frequency range
Because the signal frequency of the carrier wave transmitting apparatus of different manufacturers emission requires within the specific limits, correspondingly, receiver also should be able to normally receive signal in this frequency range.Therefore the frequency range of test receiver institute energy acknowledge(ment) signal must be in certain deviation range, system's frame of test frequency scope utilizes one in described signal xegregating unit, carrier wave receiving equipment to be measured, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit, frequency analyzer, computer and two blenders to realize as shown in figure 14; The ofdm signal that the carrier wave transmitting apparatus sends should cover the entire transmit signal frequency range, and whether the detected carrier receiving equipment can normally receive signal, and various mode of operations should be tested respectively.
Blender among the figure uses as power splitter for the mixer ZSC-2-1 that Mini-Circuits company produces herein.The distribution loss of ZSC-2-1 is 3dB.
Utilize described carrier wave transmitting apparatus to be measured, send the carrier signal of different frequency point, by behind the described blender signal being divided into two-way, one road signal is transferred to described frequency analyzer through described coupling circuit, through measuring the accurate frequency values that transmits, another road signal is transferred to described carrier wave receiving equipment to be measured;
Described carrier wave receiving equipment to be measured, carrier wave transmitting apparatus to be measured are connected to described computer respectively by serial ports, described carrier wave receiving equipment to be measured receives the carrier signal of being sent by described carrier wave transmitting apparatus to be measured, and send described computer simultaneously to, whether correctly received by described computer-made decision;
Described signal xegregating unit is used for isolating the High-frequency Interference on the electricity network;
Described standard 50 Ω impedance electric power networks are used for the test circuit impedance stabilization about 50 Ω.
In Figure 15, for graphic convenience, computer does not show.But, those skilled in the art as can be known, the test general system set-up figure by Fig. 1 as can be seen, computer is connected on the bus by serial ports, then the various piece of this detection system can be carried out data communication by serial ports and computer.
18) reflection loss
The test purpose of reflection loss is to detect receiver inlet impedance matching situation, and unit is decibel (dB).If sending-end impedance does not match, then can cause the signal attenuation that is caused by reflection.Utilize the whole operating frequency range of network analyzer scanning radio, record tested receiver reflection loss be the result of reflection point of maximum intensity in the whole scanning band as reflection loss, this value must be within the specific limits.Test system structure as shown in figure 15.
19) suppressor pulse interference performance
In low pressure OFDM carrier communication, with the asynchronous recurrent pulses noise of power frequency and with the irrelevant single event impulsive noise of system frequency be very important two noise likes, so require receiver that good suppressor pulse interference performance will be arranged.Under carrier equipment normal transmission signal and the normal situation about receiving of receiving equipment, add recurrent pulses noise and the single event noise asynchronous with power frequency respectively, increase pulse duration gradually and can normally receive up to receiver, pulse duration at this moment is designated as the tested receiver suppressor pulse disturbs width.The test macro frame utilizes one in described signal xegregating unit, carrier wave receiving equipment to be measured, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit, signal generator, computer and two blenders to realize as shown in figure 16.
Utilize described carrier wave transmitting apparatus to be measured, send carrier signal, as first via measured signal; By signal generator production burst interference signal, as the second tunnel measured signal, by behind the blender two paths of signals being synthesized one road signal, be transferred to carrier wave receiving equipment to be measured simultaneously.Described carrier wave receiving equipment to be measured, carrier wave transmitting apparatus to be measured are connected to described computer respectively by serial ports, described carrier wave receiving equipment to be measured receives the test carrier signal of being sent by carrier wave transmitting apparatus to be measured, and send described computer simultaneously to, there is computer-made decision whether correctly to receive.
Described signal xegregating unit is used for isolating the High-frequency Interference on the electricity network;
Described standard 50 Ω impedance electric power networks are used for the test circuit impedance stabilization about 50 Ω.
Similar to Figure 15, the computer among Figure 16 does not show yet.But, those skilled in the art still as can be known, the test general system set-up figure by Fig. 1 as can be seen, computer is connected on the bus by serial ports, then the various piece of this detection system can be carried out data communication by serial ports and computer.
20) suppress with frequency, face interference performance frequently
Except noise, ofdm signal may run in the PLC transmission course in addition with frequently and face frequently and disturb, and just requires this moment receiver opposing preferably to be arranged with frequently and face interference performance frequently.The test macro frame as shown in figure 17, described low pressure OFDM carrier wave physical layer communication performance detecting system further comprises one second carrier wave transmitting apparatus to be measured;
Utilize one of described signal xegregating unit, carrier wave receiving equipment to be measured, two carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks and two blenders to realize.
In test, should test according to following steps, or take process of equal value:
A) at first carrier wave transmitting apparatus to be measured is adjusted to the normal transmission signal, carrier wave receiving equipment to be measured can normally receive signal simultaneously.
B) frequency range with the second carrier wave transmitting apparatus transmission signal to be measured is adjusted to frequency range identical with carrier wave transmitting apparatus to be measured or that face mutually.
C) output level of the increase second carrier wave transmitting apparatus to be measured makes carrier wave receiving equipment to be measured normally to receive.
D) output level that reduces the second carrier wave transmitting apparatus to be measured gradually reaches the threshold value that carrier wave receiving equipment to be measured just in time can normally receive.
E) with this channel standard input signal level with this moment co-channel interference signal level ratio be designated as tested receiver Digital Television co channel rejection ratio.
21) suppress 0dB echo ability, inhibition multipath ability
Low voltage electric network topological structure complexity, branch is many, and decay is big, causes multipath reflection, causes selective attenuation and the intersymbol interference of signal.This index is to test under the conditions of two footpath transmission, the ability of receiver opposing echo when the interference attenuation of echo is 0dB.System's frame of test utilizes one of described signal xegregating unit, carrier wave receiving equipment to be measured, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, signal imitation instrument, Gaussian white noise generator and two blenders to realize as shown in figure 18.
In the test, should test according to following steps, or take process of equal value, following for suppressing the test process of echo ability:
A) carrier wave transmitting apparatus to be measured and carrier wave receiving equipment to be measured are adjusted into normal transmission and accepting state.
B) by two footpath models the channel simulation instrument is set, echo attenutation is 0dB.
C) increase the echo time-delay, carrier wave receiving equipment to be measured can't normally be received.
D) progressively reduce echo time-delay, can normally receive again up to carrier wave receiving equipment to be measured, with this moment echo be designated as maximum echo time-delay with respect to the time-delay of signal.
E) the echo time-delay is decided to be a definite value, connects Gassian noise generator, increase noise power, make carrier wave receiving equipment to be measured take defeat, then reduce noise power gradually, recover normal until receiver and receive.
F) ratio of record wave power and noise power is 0dB echo rejection ratio.
Following for suppressing the test process of multipath ability:
A) by multipath model (Rayleigh channel or Rice channel) the channel simulation instrument is set.
B) connect Gassian noise generator, increase noise power, make tested carrier wave receiving equipment cisco unity malfunction to be measured.
C) reduce noise power gradually, can normally receive until carrier wave receiving equipment to be measured.
D) ratio of note carrier power this moment and noise power is the static multipath carrier-to-noise ratio of tested receiver thresholding.
22) the carrier-to-noise ratio thresholding under the Gaussian channel
This test is one of the most basic test index of transmission system for assessment of the ability of the anti-white Gaussian noise of low pressure OFDM carrier communication system.The test system structure frame utilizes described signal xegregating unit, carrier wave receiving equipment to be measured, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit, frequency analyzer, two adjustable attenuators, signal imitation instrument, Gaussian white noise generator and two blenders to realize as shown in figure 19.
In the test, should test according to following steps, or take process of equal value:
A) pad value of adjustable attenuator is transferred to maximum.
B) adjust the value of transmitting the signal adjustable attenuator and make carrier wave transmitting apparatus to be measured and carrier wave receiving equipment to be measured all can normally send and receive signal, the power that frequency spectrograph is shown is designated as signal power C.
C) value that reduces adjustable attenuator takes defeat carrier wave receiving equipment to be measured.
D) value that progressively increases adjustable attenuator just in time can normally receive up to carrier wave receiving equipment to be measured, and the pad value of transmission signal attenuator is transferred to maximum, and the power that spectrum analyzer is shown is designated as noise power N.
E) calculate carrier-to-noise ratio C/N, be designated as the carrier-to-noise ratio thresholding under the Gaussian channel.
23) anti-phase noise ability
Because the sensitiveness of the phase noise of OFDM, so the anti-phase noise performance of receiver also is a very important index, system's frame of the anti-phase noise ability of the utility model test receiver as shown in figure 20, described low pressure OFDM carrier wave physical layer communication performance detecting system further comprises one second Gaussian white noise generator, utilizes described signal xegregating unit, carrier wave receiving equipment to be measured, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit, the PLC demodulated equipment, frequency analyzer, two adjustable attenuators, signal generator, Gaussian white noise generator, second Gaussian white noise generator and two blenders are realized.
In the anti-phase noise performance test of the present utility model, should test according to following steps, or take process of equal value:
A) regulate output and the signal generator setting of second Gassian noise generator, make signal generator produce signal and have certain phase noise, make signal that signal generator produces input to upconverter as the local oscillation signal of subcarrier.
B) the attenuator pad value of Gassian noise generator is set at maximum and makes carrier wave transmitting apparatus and carrier wave receiving equipment all can normally send and receive signal, the power that spectrum analyzer is shown is designated as signal power C.
C) value that reduces adjustable attenuator takes defeat carrier wave receiving equipment to be measured.
D) value that progressively increases adjustable attenuator just in time can normally receive up to receiver.
E) pad value that will transmit signal attenuator is transferred to maximum, and the power that spectrum analyzer is shown is designated as noise power N.
F) calculate carrier-to-noise ratio C/N, be designated as and have the carrier-to-noise ratio thresholding under the Gaussian channel under the phase noise condition.
If there is no phase noise in theory, the value that records is the carrier-to-noise ratio thresholding under the white Gaussian noise channel, exists under the situation of phase noise, and the thresholding that records should be higher than the carrier-to-noise ratio thresholding under the white Gaussian noise channel.The threshold value that records and the carrier-to-noise ratio thresholding under the Gaussian channel are more approaching, and the anti-phase noise ability of surperficial carrier wave receiving equipment to be measured is more strong.
It is to be noted, in the accompanying drawing some is graphic, some is based on emphasizing that signal is flowed to, the part of not drawing computer, but those skilled in the art should learn, the test general system set-up figure by Fig. 1 as can be seen, computer is connected on the bus by serial ports, and then the various piece of this detection system can be carried out data communication by serial ports and computer where necessary.
By above-mentioned the low pressure OFDM carrier wave physical layer communication performance detecting system that utilizes the utility model embodiment is carried out the elaboration of every emitting performance index and receptivity index, as can be seen, compared to detection system in the past, the utility model detects all functions to be incorporated in the rack and carries out, easily every index is carried out DCO, whole system has very high conformability, and has improved detection efficiency.
In low pressure OFDM carrier wave physical layer communication performance detecting system of the present utility model, two adjustable attenuators are identical, two blenders are also identical, when in circuit, only using one, any one can, therefore, if in test circuit, use one, then be not clipped to the code area which the end is, referring to can for any one.And, in above-described embodiment of the present utility model, signal analyzer can adopt the NI PXI-5660 of American National instrument company, frequency analyzer can adopt the NI PCI-5114 of American National instrument company, signal generator can adopt the E4438C of U.S. Agilent company, the AC power meter can adopt the GPM8212 of Goodwill company, Gaussian white noise generator can adopt the UFX7110 of U.S. NoiseCom company, adjustable attenuator can adopt the 8494A of U.S. Hewlett-Packard Corporation, the channel simulation instrument can adopt the N5106A of U.S. Agilent company, network analyzer can adopt the E5061A of U.S. Agilent company, line impedance stabilization net work LISN can adopt the MPW201 of Japanese Micronix company, and blender can adopt the ZSC-2-1 of U.S. Mini-Circuits company.
The low pressure OFDM carrier wave physical layer communication performance detecting system of utility model embodiment, specially at the technical characterstic of the low-voltage powerline carrier communication of OFDM modulation system, can carry out DCO to the main performance index of this communication mode, testing process is convenient, system combination is strong, system cost is low, saves space and human cost.
Above-described specific embodiment; the purpose of this utility model, technical scheme and beneficial effect are further described; institute is understood that; the above only is specific embodiment of the utility model; and be not used in and limit protection range of the present utility model; all within spirit of the present utility model and principle, any modification of making, be equal to replacement, improvement etc., all should be included within the protection range of the present utility model.
Claims (21)
1. a low pressure OFDM carrier wave physical layer communication performance detecting system is characterized in that described system is for detection of emitting performance index and the receptivity index of low pressure OFDM carrier wave physical layer, and it comprises:
Isolation signals equipment, standard carrier transmitting apparatus, carrier wave transmitting apparatus to be measured, carrier wave receiving equipment to be measured, standard 50 Ω impedance electric power networks, coupling circuit, two blenders, two adjustable attenuators, Gaussian white noise generator, line impedance stabilization net work, PLC demodulated equipment, AC power meter, 220V AC power, signal generator, network analyzer, spectrum analyzer, channel simulation instrument, signal analyzer and computers;
Wherein, described isolation signals equipment, standard carrier transmitting apparatus, carrier wave transmitting apparatus to be measured, carrier wave receiving equipment to be measured, standard 50 Ω impedance electric power networks are connected to outside electricity network; Described carrier wave transmitting apparatus to be measured and described carrier wave receiving equipment to be measured are connected to a bus by serial ports, described coupling circuit, Gaussian white noise generator, line impedance stabilization net work, PLC demodulated equipment, signal generator, network analyzer, spectrum analyzer, channel simulation instrument and signal analyzer are connected to described bus, and described PLC demodulated equipment is connected to described computer by serial ports;
Described two blenders are arranged in described detection system, when using, it are inserted test circuit, signal is mixed and along separate routes, and will through mixing and along separate routes after signal send described computer to by serial ports and carry out the data processing;
Described two adjustable attenuators are arranged in described detection system, when using, it is inserted test circuit, for detection of the performance of the anti-white Gaussian noise of low pressure OFDM carrier communication system, when carrying out this detection, described two adjustable attenuators are linked in the described bus.
2. low pressure OFDM carrier wave physical layer communication performance detecting system as claimed in claim 1, it is characterized in that described emitting performance index comprises: OFDM reference carrier frequency, OFDM frequency bandwidth, OFDM carrier frequency stability, logic time domain specification, the test of range error vector, harmonic wave and clutter test, power output accuracy, symbol be error, transmitter modulation accuracy, crest factor, overall efficiency all the time.
3. low pressure OFDM carrier wave physical layer communication performance detecting system as claimed in claim 1, it is characterized in that described receptivity index comprises: signal receiving sensitivity, transmission data consistency, bit error rate, frame error rate, received signal quality consistency, receive frequency range, reflection loss, suppressor pulse interference performance, suppress with frequently, face frequently interference performance, suppress 0db echo ability, suppress carrier-to-noise ratio thresholding, anti-phase noise ability under multipath ability, the Gaussian channel.
4. low pressure OFDM carrier wave physical layer communication performance detecting system as claimed in claim 2, it is characterized in that, when detecting described OFDM reference carrier frequency index, utilize described signal xegregating unit, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit and frequency analyzer to realize;
Described carrier transmit equipment output measured signal to be measured becomes the light current high-frequency signal by described coupling circuit, is transferred to described frequency analyzer and carries out spectrum analysis;
Described signal xegregating unit is used for isolating the High-frequency Interference on the electricity network;
Described standard 50 Ω impedance electric power networks are used for the test circuit impedance stabilization about 50 Ω.
5. low pressure OFDM carrier wave physical layer communication performance detecting system as claimed in claim 2, it is characterized in that, when detecting described OFDM frequency bandwidth index, utilize described signal xegregating unit, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit and frequency analyzer to realize;
The signal amplitude of the measured signal that described carrier wave transmitting apparatus to be measured is sent is transferred to the maximum of indicating in the equipment service manual, carry out spectrum analysis by described frequency analyzer, described frequency bandwidth is all hanging down 20dB with interior siding-to-siding block length than frequency amplitude maximum for analyzing all frequency amplitudes that obtain.
6. low pressure OFDM carrier wave physical layer communication performance detecting system as claimed in claim 2, it is characterized in that, when detecting described logic time domain specification index, utilize described signal xegregating unit, standard carrier transmitting apparatus, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit and frequency analyzer to realize;
By transmitting time between described carrier wave transmitting apparatus to be measured and the described standard carrier transmitting apparatus to recently whether decision logic passage time domain specification qualified.
7. low pressure OFDM carrier wave physical layer communication performance detecting system as claimed in claim 2 is characterized in that, when detecting described range error vector index, utilizes described standard carrier transmitting apparatus, carrier wave transmitting apparatus to be measured and signal analyzer to realize;
The signal that described carrier wave transmitting apparatus to be measured and described standard carrier transmitting apparatus are sent transfers to described signal analyzer, carries out the amplitude vector error comparative analysis of signal.
8. low pressure OFDM carrier wave physical layer communication performance detecting system as claimed in claim 2, it is characterized in that, when detecting described power output accuracy index, utilize described signal xegregating unit, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit, frequency analyzer and computer to realize;
The signal that described carrier wave transmitting apparatus to be measured is sent is transferred to described frequency analyzer, directly power data is transferred to computer read-out power value size by described frequency analyzer.
9. low pressure OFDM carrier wave physical layer communication performance detecting system as claimed in claim 2, it is characterized in that, when detecting described symbol clock error criterion, utilize described signal xegregating unit, standard carrier transmitting apparatus, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit and frequency analyzer to realize;
By the transmitting time between described carrier wave transmitting apparatus to be measured and the described standard carrier transmitting apparatus to recently obtaining described symbol clock error.
10. low pressure OFDM carrier wave physical layer communication performance detecting system as claimed in claim 2, it is characterized in that, when detecting described crest factor index, utilize described signal xegregating unit, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit and frequency analyzer to realize;
Obtain the peak value of the signal that described carrier wave transmitting apparatus to be measured sends and the ratio of root-mean-square value by described frequency analyzer, be described crest factor.
11. low pressure OFDM carrier wave physical layer communication performance detecting system as claimed in claim 2, it is characterized in that, when detecting described overall efficiency index, utilize described signal xegregating unit, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit, frequency analyzer, computer and 220V AC power and AC power meter to realize;
Described carrier transmit equipment output measured signal to be measured becomes the light current high-frequency signal by described coupling circuit, is transferred to described frequency analyzer and carries out spectrum analysis;
Described AC power meter is used for the power loss of described carrier wave transmitting apparatus to be measured is measured;
Described signal xegregating unit is used for isolating the High-frequency Interference on the electricity network;
Described standard 50 Ω impedance electric power networks are used for the test circuit impedance stabilization about 50 Ω.
12. low pressure OFDM carrier wave physical layer communication performance detecting system as claimed in claim 3, it is characterized in that, when detecting described signal receiving sensitivity index, utilize described signal xegregating unit, carrier wave transmitting apparatus to be measured, carrier wave receiving equipment to be measured, line impedance stabilization net work, coupling circuit and channel simulation instrument, signal analyzer to realize;
Described carrier transmit equipment to be measured is connected on the described electricity network by described line impedance stabilization net work and signal xegregating unit, and send communication message continuously, described communication message sends to described signal analyzer, carries out first frequency conversion and AD conversion back and stores in the mode of digital signal;
Described carrier wave receiving equipment to be measured receives the digital signal after the described storage, utilize described channel simulation instrument to change power output, constantly make described digital signal decay, take defeat up to described signal analyzer demonstration, the power output of this moment is the receiving sensitivity of described carrier wave receiving equipment to be measured.
13. low pressure OFDM carrier wave physical layer communication performance detecting system as claimed in claim 3, it is characterized in that, when detecting described transmission data consistency index, utilize described signal xegregating unit, standard carrier transmitting apparatus, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, PLC demodulated equipment and computer to realize;
Described PLC demodulated equipment carries out demodulation respectively with the signal that described standard carrier transmitting apparatus and carrier wave transmitting apparatus to be measured send, but coding is conciliate in not deinterleaving, the signal after the described demodulation is sent to described computer carry out the data comparative analysis.
14. low pressure OFDM carrier wave physical layer communication performance detecting system as claimed in claim 3, it is characterized in that, when detecting described bit error rate index, utilize described signal xegregating unit, carrier wave receiving equipment to be measured, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks and computer to realize;
Described carrier wave receiving equipment to be measured, carrier wave transmitting apparatus to be measured are connected to described computer respectively by serial ports, described carrier wave transmitting apparatus to be measured sends a signal to described carrier wave receiving equipment to be measured, and send described computer simultaneously to, after described computer received the signal that described carrier wave receiving equipment to be measured transmits, the signal that itself and described measured signal transmitting apparatus are transmitted carried out the contrast of bit error rate;
Described signal xegregating unit is used for isolating the High-frequency Interference on the electricity network;
Described standard 50 Ω impedance electric power networks are used for the test circuit impedance stabilization about 50 Ω.
15. low pressure OFDM carrier wave physical layer communication performance detecting system as claimed in claim 3, it is characterized in that, when detecting described received signal quality coincident indicator, utilize described signal xegregating unit, carrier wave receiving equipment to be measured, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit, signal generator and computer to realize;
Described carrier wave receiving equipment to be measured, carrier wave transmitting apparatus to be measured are connected to described computer respectively by serial ports, described carrier wave transmitting apparatus to be measured sends a signal to described carrier wave receiving equipment to be measured, and send described computer simultaneously to, described signal generator is connected to described computer by described coupling circuit, in channel, inject the noise signal that presets, the signal that the signal that the carrier wave receiving equipment described to be measured that described computer reception has added noise transmits and described measured signal transmitting apparatus transmit carries out both the contrast of bit error rate;
Described signal xegregating unit is used for isolating the High-frequency Interference on the electricity network;
Described standard 50 Ω impedance electric power networks are used for the test circuit impedance stabilization about 50 Ω.
16. low pressure OFDM carrier wave physical layer communication performance detecting system as claimed in claim 3, it is characterized in that, when detecting described receive frequency range index, utilize one in described signal xegregating unit, carrier wave receiving equipment to be measured, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit, frequency analyzer, computer and two blenders to realize;
Utilize described carrier wave transmitting apparatus to be measured, send the carrier signal of different frequency point, by behind the described blender signal being divided into two-way, one road signal is transferred to described frequency analyzer through described coupling circuit, through measuring the accurate frequency values that transmits, another road signal is transferred to described carrier wave receiving equipment to be measured;
Described carrier wave receiving equipment to be measured, carrier wave transmitting apparatus to be measured are connected to described computer respectively by serial ports, described carrier wave receiving equipment to be measured receives the carrier signal of being sent by described carrier wave transmitting apparatus to be measured, and send described computer simultaneously to, whether correctly received by described computer-made decision;
Described signal xegregating unit is used for isolating the High-frequency Interference on the electricity network;
Described standard 50 Ω impedance electric power networks are used for the test circuit impedance stabilization about 50 Ω.
17. low pressure OFDM carrier wave physical layer communication performance detecting system as claimed in claim 3, it is characterized in that, when detecting described suppressor pulse interference performance index, utilize one in described signal xegregating unit, carrier wave receiving equipment to be measured, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit, signal generator, computer and two blenders to realize;
Utilize described carrier wave transmitting apparatus to be measured, send carrier signal, as first via measured signal; Simultaneously by described signal generator production burst interference signal, as the second tunnel measured signal, by described blender two paths of signals is synthesized one road signal, be transferred to described carrier wave receiving equipment to be measured, described carrier wave receiving equipment to be measured, carrier wave transmitting apparatus to be measured are connected to described computer respectively by serial ports, described carrier wave receiving equipment to be measured receives the test carrier signal of being sent by carrier wave transmitting apparatus to be measured, and send described computer simultaneously to, whether correctly received by described computer-made decision;
Described signal xegregating unit is used for isolating the High-frequency Interference on the electricity network;
Described standard 50 Ω impedance electric power networks are used for the test circuit impedance stabilization about 50 Ω.
18. low pressure OFDM carrier wave physical layer communication performance detecting system as claimed in claim 3, it is characterized in that, detecting described inhibition with frequently, when facing frequency interference performance index, described low pressure OFDM carrier wave physical layer communication performance detecting system further comprises one second carrier wave transmitting apparatus to be measured;
Utilize one of described signal xegregating unit, carrier wave receiving equipment to be measured, two carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks and two blenders to realize.
19. low pressure OFDM carrier wave physical layer communication performance detecting system as claimed in claim 3, it is characterized in that, detect described 0db clawback ability, when suppressing multipath ability index, utilizing one of described signal xegregating unit, carrier wave receiving equipment to be measured, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, signal imitation instrument, Gaussian white noise generator and two blenders to realize.
20. low pressure OFDM carrier wave physical layer communication performance detecting system as claimed in claim 3, it is characterized in that, during carrier-to-noise ratio thresholding index under detecting described Gaussian channel, utilize described signal xegregating unit, carrier wave receiving equipment to be measured, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit, frequency analyzer, two adjustable attenuators, signal imitation instrument, Gaussian white noise generator and two blenders to realize.
21. low pressure OFDM carrier wave physical layer communication performance detecting system as claimed in claim 3, it is characterized in that, when detecting described anti-phase noise ability index, described low pressure OFDM carrier wave physical layer communication performance detecting system further comprises one second Gaussian white noise generator, utilizes described signal xegregating unit, carrier wave receiving equipment to be measured, carrier wave transmitting apparatus to be measured, standard 50 Ω impedance electric power networks, coupling circuit, the PLC demodulated equipment, frequency analyzer, two adjustable attenuators, signal generator, Gaussian white noise generator, second Gaussian white noise generator and two blenders are realized.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103605941A (en) * | 2013-09-06 | 2014-02-26 | 珠海银邮光电技术发展股份有限公司 | System and method for testing reception sensitivity of UHF-band RFID radio frequency tag chip |
| CN103605942A (en) * | 2013-09-16 | 2014-02-26 | 珠海银邮光电信息工程有限公司 | System and method for testing reception sensitivity of UHF-band RFID card reader chip |
| CN107294626A (en) * | 2017-05-16 | 2017-10-24 | 上海卫星工程研究所 | Efficient high bit rate signal test method for bit error rate |
-
2013
- 2013-04-03 CN CN2013201656150U patent/CN203180921U/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103605941A (en) * | 2013-09-06 | 2014-02-26 | 珠海银邮光电技术发展股份有限公司 | System and method for testing reception sensitivity of UHF-band RFID radio frequency tag chip |
| CN103605941B (en) * | 2013-09-06 | 2017-02-15 | 珠海银邮光电技术发展股份有限公司 | System and method for testing reception sensitivity of UHF-band RFID radio frequency tag chip |
| CN103605942A (en) * | 2013-09-16 | 2014-02-26 | 珠海银邮光电信息工程有限公司 | System and method for testing reception sensitivity of UHF-band RFID card reader chip |
| CN103605942B (en) * | 2013-09-16 | 2017-02-01 | 珠海银邮光电信息工程有限公司 | System and method for testing reception sensitivity of UHF-band RFID card reader chip |
| CN107294626A (en) * | 2017-05-16 | 2017-10-24 | 上海卫星工程研究所 | Efficient high bit rate signal test method for bit error rate |
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