CN101610118A - The method of measurement of characteristics of signal transmission passage and measurement mechanism - Google Patents
The method of measurement of characteristics of signal transmission passage and measurement mechanism Download PDFInfo
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Abstract
A kind of method of measurement of characteristics of signal transmission passage and measurement mechanism, in order to transmit the characteristic of measuring the transmission channel between this dispensing device and this receiving system in service signal to a receiving system at a dispensing device, comprise: a. is in the signal input part of this dispensing device, stack one test signal on this service signal, wherein, this service signal is uncorrelated with this test signal, and uncorrelated mutually at test signals same service signal, a plurality of; B. in the signal output part of this receiving system, obtain a business and test mixing transmission signal; C. this business and test mixing transmission signal are handled, obtained the instantaneous estimation value of channel characteristic; D. the instantaneous estimation value of channel characteristic is carried out low-pass filtering eliminating this service signal to the channel characteristic estimation effect, and obtain the characteristic of this transmission channel.Test signal is irrelevant substantially with the service signal of communicating by letter, and can not influence communication quality, and can save the realization cost.
Description
Technical field
The present invention relates to the transmission of digital signal, relate in particular to the measurement of the characteristic of digital data transmission passage.
Background technology
The transmission system of existing digital signal as shown in Figure 1, supposes that T end and S hold the communication equipment that is in the different location will carry out two-way communication, and transmission medium can be air, cable, optical fiber etc.The signal energy that they send is not enough to directly be received by the other side and need trunking that signal is amplified.Wherein, signal transmission passage (hereinafter to be referred as: channel) comprise transtation mission circuit, transmission medium, intermediate equipment, receiving circuit etc.Send and receive not when same place, be called forward channel from the signal transmission passage that sends to reception.Signal transmission passage when sending and being received in same place is called crosstalk channels.The signal transmission passage that trunking transtation mission circuit output signal is leaked to receiving circuit is called the relaying crosstalk channels, and equipment sends the signal transmission passage of holding the signal process miscellaneous equipment that sends to be beamed back the equipment receiving terminal again and is called far end crosstalk channel.
In order to improve communication quality, extremely important to the detection of forward channel, relaying crosstalk channels, far end crosstalk channel transmission characteristic, this is mainly reflected in:
1) because forward channel undesirable, signal can distort in transmission course, thereby influences communication quality.If energy measurement goes out channel transfer characteristic, just can take balanced measure to weaken the harmful effect that the transmission distortion brings at receiving terminal;
2) relaying is crosstalked can influence signal quality greatly, and equipment can self-oscillation when serious.If energy measurement goes out the crosstalk channels transmission characteristic, just can offset AXT, thereby reduce the influence of receive-transmit isolation greatly at device interior;
3) far-end cross talk can influence the quality of received signal equally.If energy measurement goes out the far-end cross talk transmission characteristic, just the crosstalk counteracting that produces in remote equipment of the signal that can send this equipment in received signal falls.
And the measurement of the existing characteristic of channel exists problems, such as:
1) the forward path equalization algorithm needs different equalization algorithms with closely related with the service signal of communicating by letter, different signal form;
2) equalization algorithm may converge on non-optimum in addition relatively poor state on, thereby influence communication quality;
3) Chang Gui LMS, RLS scheduling algorithm are used to feed back or the computing complexity during Echo Cancellation, and software and hardware realizes that cost is higher and operation time is longer.
Summary of the invention
The present invention is intended to overcome the deficiencies in the prior art, and the measuring technique that provides a kind of and have nothing to do substantially with the service signal of communicating by letter, can not influence communication quality and can save the characteristics of signal transmission passage of realizing cost.
To achieve these goals, the present invention proposes a kind of method of measurement of characteristics of signal transmission passage, in order to transmit the characteristic of measuring the transmission channel between this dispensing device and this receiving system in service signal to a receiving system at a dispensing device, comprise step:
A, in the signal input part of this dispensing device, on this service signal the stack one test signal, wherein, this service signal is uncorrelated with this test signal, and uncorrelated mutually at test signals same service signal, a plurality of;
B, in the signal output part of this receiving system, obtain a business and test mixing transmission signal;
C, described business and test mixing transmission signal are handled, in the transmission channel bandwidth with described business and test mixing transmission signal frequency spectrum frequency spectrum divided by test signal, to remove the influence of test signal frequency spectrum amplitude and phase change on the transmission channel bandwidth, obtain the instantaneous estimation value of transmission channel characteristics;
D, the instantaneous estimation value of described transmission channel characteristics is carried out filtering,, and obtain the characteristic of this transmission channel with the influence of filtering service signal transmission component and channel noise with low pass filter.
In step c: the measure that described business and test mixing transmission signal are handled can be: deconvolution, matched filtering or related operation.
Further, the present invention also proposes a kind of in order to realize the measurement mechanism of above-mentioned method of measurement, and wherein, dispensing device comprises:
One generator that sends test massage, its output one sends test massage;
One adder comprises two inputs and an output, an input termination described service signal wherein, and wherein termination is described sends test massage in another input, and described output provides the mixed signal of this service signal and test signal;
Receiving system comprises:
One signal processor comprises an input and an output, wherein be input as through the transmission after service signal and the mixed signal of test signal, described output provides the characteristic instantaneous estimation value of this transmission channel.
One low pass filter, it is input as the characteristic instantaneous estimation value of transmission channel, and it is output as the characteristic mean estimates of transmission channel.
This signal processor can be a deconvolution processor, and its frequency domain transmission response is the inverse of test signal frequency spectrum in the transmission channel bandwidth.
And, the frequency spectrum of the correlation function of test event signal approximately equalised words of amplitude on each frequency in transmission bandwidth, the deconvolution computing just can replace the matched filtering or the related operation of test signal, the deconvolution processor can replace with matched filter, perhaps replace with associative processor and reception reference signal generator, so:
This signal processor also can be a matched filter, and its time domain impulse response is the complex conjugate of the test signal of time inverted order.
This signal processor can also be to comprise a reference signal generator and an associative processor,
This reference signal generator output one receives reference signal, this reception reference signal is identical with the waveform that sends test massage, apparently, if dispensing device and receiving system are in the same equipment, then this reception reference signal generator and the generator that sends test massage can be to unite two into one;
This associative processor comprises two inputs and an output, wherein one be input as described reception reference signal, wherein another be input as through the transmission after service signal and the mixed signal of test signal, described output provides the characteristic instantaneous estimation value of this transmission channel.
Compared with prior art, adopt the method for measurement and the measurement mechanism of characteristics of signal transmission passage of the present invention, irrelevant substantially with the service signal of communicating by letter, communication quality can be do not influenced, and the realization cost can be saved.
Description of drawings
Fig. 1 is the theory diagram of the transmission system of existing digital signal;
Fig. 2 is the theory diagram of forward channel characteristic measurement method of the present invention;
Fig. 3 crosstalks for relaying of the present invention, the theory diagram of far end crosstalk channel characteristic measurement method;
Fig. 4 is the theory diagram of forward channel characteristic measuring device of the present invention;
Fig. 5 is the theory diagram of relaying crosstalk channels characteristic measuring device of the present invention;
Fig. 6 is the theory diagram of far end crosstalk channel characteristic measuring device of the present invention.
Embodiment
Below in conjunction with accompanying drawing, the present invention is given elaboration further.
Channel transfer characteristic can be represented with the time domain impulse response of channel, the frequency domain representation that the Fourier conversion just can obtain channel transfer characteristic is carried out in the impulse response of time domain.In theory, in order to obtain channel transfer characteristic, can adopt the mode of the impulse response of measured channel.Send a desirable impact signal (energy is 1, amplitude infinity, the short ideal pulse of infinite duration) and, write down the response of channel then as test signal.But desirable impulse response is impossible, also be unnecessary, in real work, adopt other attainable signal form to replace, as long as in interested channel width, 0 power points does not appear in the frequency spectrum of known test signal, can offset test signal amplitude and the unfavorable influence of phase characteristic by certain algorithm, obtain channel transfer characteristic, this channel transfer characteristic can be expressed as a string sampled data sequence or zero pole model, it is the response of unit amplitude pulse signal on channel transfer, and the convolution of other signal and this response can obtain the response of this signal on channel transfer.
Fig. 2 is the measurement of transmission characterist method of forward channel.The T end is in different places with S end equipment, and test signal is dealt on the forward channel and transmits through T end transtation mission circuit, is received circuit by the S termination afterwards and receives.The deconvolution computing is in order to offset this amplitude in the signal transmission bandwidth of test signal and the influence of phase change.Through obtaining the transmission characteristic of forward channel after the deconvolution.
Fig. 3 is the characteristic test method of relaying or far end crosstalk channel, and transmission and receiving circuit are in the same equipment, and the deconvolution circuit can utilize the timing information of test signal.
In order to obtain measurement of transmission characterist result more accurately, eliminate the interference of other noise or signal, can repeat repeatedly the measurement of transmission characteristic, each test signal that sends both can be the same, also can be different, both can wait the cycle to repeat, also can not wait the cycle to repeat.But, require the time interval or repetition period between each the measurement enough big, influence to such an extent as to their transmission response can not overlap each other.
Consider that the deconvolution computing realizes going up more complicated, under following two kinds of situations, can simplify.Certainly simplifying the error brought should be within the acceptable range:
1. test event signal length is shorter, its auto-correlation function is near an individual pulse, its frequency spectrum is the amplitude approximately equal in transmission bandwidth, only be used to offset this phase change in the signal transmission bandwidth of test signal during the deconvolution computing, just can use to replace, perhaps adopt approximate replacement of relevant treatment test signal to the matched filtering of test signal is approximate.The impulse response of matched filtering is the complex conjugate of the test signal of time inverted order;
2. test event signal length is longer, supposes that transmission channel duration time response is Td, the frequency spectrum of the correlation function of test signal after the 2*Td time window blocks amplitude approximately equal in transmission bandwidth, and the deconvolution computing just can replace with related operation is approximate.
Need to prove that matched filtering and relevant treatment are of equal value, interchangeable in theory, but realize that in test signal matched filtering more in short-term signal realization cost is only and can accepts, and adopts relevant treatment usually when test signal is longer.And relevant treatment needs a reference signal identical with the test signal waveform.
A kind of optional mode signal test is exactly a pulse, and the interval between the pulse is greater than the duration of channel transfer characteristic time-domain response.But the energy that individual pulse comprises very little, may need accumulation very for a long time average.
For energization can adopt the test signal of auto-correlation function near pulse, as 13 Barker codes etc., its length has only 13, can adopt deconvolution to handle.
The another kind of the most frequently used signal form of using as test signal is pseudorandom (PN) M sequence, and length is 2
N-1, N is a positive integer, and the auto-correlation function in its cycle is 2 for height of stack on-1 DC level
NPulse.As long as N is enough big, the Cycle Length that makes the M sequence is much larger than transmission channel duration of response Td, approaches pulse after its auto-correlation function is blocked with the Td time window, thus the approaching desirable impulse response of acquisition.In this case, the deconvolution computing can be substituted by related operation approx.Related operation needs a reference signal the same with the test signal form usually.In the forward channel property detection, T end and S end be not in an equipment, and the S end needs a reference signal generator to produce the reference signal the same with test signal.And in the crosstalk channels property detection, T end and S end in an equipment, S hold can be directly test signal as the reference signal.
The problem to be solved in the present invention is: how to make the operation of channel transfer feature measurement not influence normal service communication signal.If service communication is stopped, in special time, send test massage specially, recover service communication again after being accomplished to a certain degree Deng measuring transmission loss, this way also is feasible in some cases, but is undesirable or even unallowed under many situations.If the characteristic of channel is slowly to change, require channel is uninterruptedly measured, frequent interrupting service communication obviously is unacceptable.
First solution that the present invention proposes is as follows: transmissions that superpose simultaneously of the known test signal of receiving-transmitting sides and service signal, test signal and service signal can be not 0 the while on the time, and test signal is not 0 in channel width on the frequency domain.For service signal, test signal is to disturb, but the average power of test signal is far below the average power of service signal, it is minimum that the existence of test signal is handled influence to the reception of service signal, only needs to improve the influence that the transmitted power of service signal just can be offset test signal minimumly.Take signal processing measures such as deconvolution, matched filtering or relevant treatment at receiving terminal after, obtain the instantaneous estimation value of channel transfer characteristic,, thereby obtain the characteristic of channel again by the level and smooth interference of removing service signal that adds up for a long time to characteristic of channel measurement.The characteristic of channel metering system of this mode is called " steal with the road and send out ".
" send out steathily " and why can use, be that the The design of communication of wireless or cable all has certain interference noise tolerance limit with the road.Transmission channel all can have external interference noise to sneak into, and therefore can require communication system to be issued to certain error rate in certain state of signal-to-noise.If the test signal that adds is little to the signal to noise ratio influence of receiving terminal intentionally, communication system still can reach the singal reporting code requirement, also just can accept.For example, 256QAM signal reliable demodulation requires to suppose that present signal to noise ratio is 33db more than the signal to noise ratio 30db, if then inject test signal power than the low 33db of service signal, still can reach the signal to noise ratio of 30db.Hanging down 40db if inject test signal power than service signal, then signal to noise ratio only worsens 0.08db.
" send out steathily " and have following characteristics with the road:
1) test signal and service signal are separate.
Test signal is not the part of service signal, not can take into account the existence of test signal during the design service signal, does not need to know the characteristic of service signal during the design test signal basically yet.Basic requirement to test signal: greater than channel width; Frequency spectrum does not have 0 power points on channel width; Uncorrelated with service signal.These three requirements do not need too many understanding to service signal knowledge, are easy to satisfy.
These characteristics make the pilot frequency system of this method measured channel characteristic different from the past, no matter are OFDM or cdma communication mode, and their pilot tones wherein are the parts of service signal, necessary and service signal synchronized transmission.
2) characteristic of channel that is applicable to constant or slow variation is measured.
Since the test signal amplitude a little less than, need long-time on average, so this method is not suitable for the measurement of the fast-changing characteristic of channel.
3) be applicable to the feature measurement of forward channel, relaying crosstalk channels and far end crosstalk channel.
Relaying is transmitted the transmission that does not allow the interrupting service signal, utilizes the signals such as pilot tone of service signal self that channel is estimated too complexity, requires the relaying forwarding unit to have abilities such as demodulation process, depends critically upon service signal.And " sending out steathily with the road " is just simply many when relaying is transmitted owing to the detailed characteristics that does not need to know service signal.
4) algorithm is simple, realizes that hardware and software cost is low.
Do not add test signal, adopt channel estimation methods such as " blind equalizations ", need utilize the characteristics of service signal, not necessarily guarantee to obtain optimum result, and operand is big.And if adopt the method for " steal with the road and send out ", operand is much smaller, suitable design test signal only needs be shifted, adds up, operation such as storage, does not need multiplier just can finish the channel characteristic measurement.
And, feature measurement at forward channel, second solution that the present invention proposes is as follows: transmissions that superpose simultaneously of the known test signal of receiving-transmitting sides and service signal, test signal and service signal can be not 0 the while on the time, and test signal is not 0 in channel width on the frequency domain.For service signal, test signal is to disturb.Take signal processing measures such as deconvolution, matched filtering or relevant treatment at receiving terminal after, obtain the instantaneous estimation value of channel transfer characteristic, add up by certain hour again and smoothly remove the interference that service signal is measured the characteristic of channel, thereby obtain the timing characteristic of channel transfer characteristic and test signal.Timing characteristic according to the characteristic of channel and test signal, the estimated value of the test signal waveform that the process channel of regenerating transmits, in received signal, deduct this estimated value to offset the test signal after transmitting, thereby remove the influence of test signal, the service signal that obtains sending is through the waveform behind the dissemination channel.
Compare with above-mentioned " sending out steathily with the road ", the test signal amplitude can be stronger, and receiving terminal can add up by the short period and smoothly remove the interference that service signal is measured the characteristic of channel, thereby obtains the characteristic of channel.The characteristic of channel metering system of this mode is called " with Lu Mingfa ".
" with Lu Mingfa " has following characteristics:
1) test signal and service signal are separate.
Test signal is not the part of service signal, not can take into account the existence of test signal during the design service signal, does not need to know the characteristic of service signal during the design test signal basically yet.Basic requirement to test signal: greater than channel width; Frequency spectrum does not have 0 power points on channel width; Uncorrelated with service signal.These three requirements do not need too many understanding to service signal knowledge, are easy to satisfy.These characteristics make the pilot frequency system of this method measured channel characteristic different from the past, no matter are OFDM or cdma communication mode, and their pilot tones wherein are the parts of service signal.
2) be applicable to that changing faster the characteristic of channel measures.
Because the test signal amplitude is stronger, average time is short, is applicable to the measurement of the fast-changing characteristic of channel.
3) only be applicable to the feature measurement of forward channel, be not suitable for the feature measurement of relaying crosstalk channels and far end crosstalk channel.
4) algorithm is simple, realizes that hardware and software cost is low.
Do not add test signal, adopt channel estimation methods such as " blind equalization ", LMS, need utilize the characteristics of service signal, not necessarily guarantee to obtain optimum result, and operand is big.And if adopt the method for " with Lu Mingfa ", operand is much smaller, suitable design test signal only needs be shifted, adds up, operation such as storage, does not need multiplier just can finish the channel characteristic measurement.
Need to prove, measure, may need a plurality of test signals if communication system need adopt such scheme to carry out channel characteristic in many places.For avoiding phase mutual interference between them, require between the test signal cross-correlation low as far as possible.
Adopt above-mentioned method, the concrete case of carrying out the channel characteristic measurement is as follows:
1. forward channel feature measurement
Forward channel feature measurement as shown in Figure 4 supposes that the channel width of communication standard regulation is 8M, and digital signal symbol sampler rate is 6.875M, and the character rate of business datum input is 6.875M like this.Test signal adopts the M sequence, and each sampling pulse displacement is exported once, and Cycle Length is greater than the time span of Channel Transmission to the broadening of signal pulse, much smaller than the coherence time of channel variation, to obtain best time average cumulative effects.Suppose that the letter time pulse signal broadening that transmission circuit and transfer channel cause is 150 sampled points (about 150/6.875=22us), be 10 seconds the coherence time of channel, also is that channel was that variation is little in 10 seconds.Selecting the M sequence period is 2
8-1=255 sampled point.
Send the M sequence generator and send 0,1 pseudo-random number sequence, the amplitude conversion 0,1 sequence transformation one-tenths+A ,-the A sequence, A is the test signal amplitude, if " with stealing on the road ", this amplitude will be much smaller than the business datum amplitude of importing; If " with Lu Mingfa ", the power proportions that this amplitude takies is determined by the margin of power of transtation mission circuit.Test signal and service signal sum send on the forward channel through a series of processing of transmitting apparatus.After receiving equipment is received signal,, become digital sampled signal again into 6.875M through a series of processing.Receive the generation of M sequence generator and send same M sequence as the reference signal, numerical value is 0,1, and just both may be inconsistent in time.Reference signal M sequence is sent into the shift register line, the different taps that postpone of output.With respect to the signal delay K sampling period of 0, the K output of input tap tap with respect to 0 place.According to tap signal received signal is carried out sign reversing (keep received signal polarity constant as 0,1 received signal got negative), the result after the sign reversing is carried out low-pass filtering.The data of the output of each tapping point low-pass filtering can be thought the transmission characteristic of forward channel time domain.The mode of low-pass filtering can be grouping cumulative mean, FIR filtering or IIR filtering.
If " with Lu Mingfa ", also needing will to obtain the transmission characteristic sign reversing with each tap signal (keeps received signal polarity constant as 0,1 received signal got negative) results added, obtain the test signal of regenerating, deduct from the service signal that receives, the service signal after test signal is disturbed is removed in output, can utilize the channel transfer characteristic that the service signal that receives is carried out equilibrium.
Utilization can be carried out carrier wave and symbol rate and follow the tracks of the measurement of transmission characteristic.The digital sample speed nominal sampling rate of transmitting apparatus and receiving equipment is 6.875M, and receiving equipment needs tracking lock transmitting apparatus symbol sampler rate and carrier phase, only in this way could proper communication.If the symbol sampler rate of receiving equipment and transmitting apparatus have less difference, each tap upper channel characteristic mean value that obtains is cyclic shift between tap ceaselessly.If both carrier frequencies are variant, variation is not being stopped in the complex phase position of each tap upper channel characteristic that obtains.Algorithm be can design in view of the above and symbol rate and carrier track carried out according to the channel characteristic of measuring.
2 relaying crosstalk channels feature measurements and crosstalking offset
Relaying crosstalk channels feature measurement as shown in Figure 5.The purposes of trunking is that processing such as a service signal of input amplifies, filtering re-send to the next stage receiving equipment.But if with frequently transmitting, the signal that sends will be gone here and there the tieback receiving end, disturbs the reception of service signal, and produces self-oscillation.To crosstalk in order eliminating, will to measure the transmission characteristic of crosstalk channels.For this reason, the service signal addition of test signal and process relay process is sent, receiving circuit carries out relevant treatment, through average, obtain the transmission characteristic of crosstalk channels, this transmission characteristic is as the coefficient of FIR filter, carry out filtering to sending signal, the crosstalk signal that obtains regenerating deducts the crosstalk signal of regeneration on received signal, just offset the influence of crosstalking to relay amplifier.
Because the crosstalk channels characteristic is not also finished measurement, and the cancellation circuit of crosstalking also can't offset fully with crosstalking, equipment may be in the self-excitation state owing to crosstalking at the equipment work initial stage, and relaying forwarding and crosstalk channels feature measurement all can't be carried out.Have only to disconnect the relaying passage for this reason, only send test massage, offset the effect back (minimum requirements is no longer self-excitation) that acquires a certain degree, carry out normal relaying again and transmit etc. crosstalk channels feature measurement and crosstalking.
The measurement of 3 far end crosstalk channel transmission characteristics and crosstalking offsets
Far end crosstalk channel feature measurement as shown in Figure 6.T end equipment sends signal and is received by S end equipment, and while S end equipment sends signal and received by T end equipment.Because far-end cross talk, the T end institute signalling that the S termination is received can be gone here and there transmitting terminal, thereby the signal that the T end sends is clipped in to send with the S end returns the T end in the signal.To crosstalk in order eliminating, will to measure the transmission characteristic of crosstalk channels.For this reason, at the T end test signal and the signal plus that will send are sent, receiving circuit carries out relevant treatment, popin is equal after filtration, obtains the transmission characteristic of crosstalk channels, and this transmission characteristic is as the coefficient of FIR filter, carry out filtering to sending signal, the crosstalk signal that obtains regenerating deducts the crosstalk signal of regeneration on received signal, just offset the influence of crosstalking to relay amplifier.The S end can be done and the same processing of T end, but the test signal coefficient correlation that requires T end and S end to be adopted is low as far as possible, otherwise both understand the phase mutual interference.
Foregoing; it only is preferred embodiment of the present invention; be not to be used to limit embodiment of the present invention; those of ordinary skills are according to main design of the present invention and spirit; can carry out corresponding flexible or modification very easily, so protection scope of the present invention should be as the criterion with the desired protection range of claims.
Claims (10)
1, a kind of method of measurement of characteristics of signal transmission passage, in order to transmitting the characteristic of measuring the transmission channel between this dispensing device and this receiving system in service signal to a receiving system at a dispensing device, the characteristic of described transmission channel is forward channel transmission characteristic, relaying crosstalk transmission characteristic and/or far-end cross talk transmission characteristic; Comprise step:
A, in the signal input part of this dispensing device, on each service signal the stack one test signal, wherein, this service signal is uncorrelated with this test signal, and uncorrelated mutually at test signals same service signal, a plurality of;
B, in the signal output part of this receiving system, obtain a business and test mixing transmission signal;
C, described business and test mixing transmission signal are handled, in the transmission channel bandwidth with described business and test mixing transmission signal frequency spectrum frequency spectrum divided by test signal, to remove the influence of test signal frequency spectrum amplitude and phase change on the transmission channel bandwidth, obtain the instantaneous estimation value of transmission channel characteristics;
D, the instantaneous estimation value of described transmission channel characteristics is carried out filtering,, and obtain the characteristic of this transmission channel with the influence of filtering service signal transmission component and channel noise with low pass filter.
2, the method for measurement of characteristics of signal transmission passage as claimed in claim 1 is characterized in that:
This test signal is uncorrelated with this service signal, and the bandwidth of this test signal is greater than the bandwidth of this service signal, and there is not 0 power points in the frequency spectrum of this test signal in the bandwidth of this service signal.
3, the method for measurement of characteristics of signal transmission passage as claimed in claim 2 is characterized in that:
The intensity of this test signal is not more than this service signal and receives the interference noise tolerance limit that detects.
4, the method for measurement of characteristics of signal transmission passage as claimed in claim 2 is characterized in that:
The intensity of this test signal receives the interference noise tolerance limit that detects greater than this service signal, utilize the transmission channel characteristics and the test signal timing characteristic that obtain, calculate the estimated value of the signal component of test signal after transmission, in received signal, deduct this estimated value, to eliminate the influence of test signal to the service signal receptivity.
5, as the method for measurement of the arbitrary described characteristics of signal transmission passage of claim 1 to 4, it is characterized in that, among the step c:
The measure that described business and test mixing transmission signal are handled is: deconvolution, matched filtering or related operation.
6, the method for measurement of characteristics of signal transmission passage as claimed in claim 5 is characterized in that:
This test signal be one through the amplitude conversion process, the cycle is 2
N-1 pseudorandom M sequence.
7, a kind of measurement mechanism of characteristics of signal transmission passage, in order to transmit the characteristic of measuring the transmission channel between this dispensing device and this receiving system in service signal to a receiving system at a dispensing device, wherein, the characteristic of described transmission channel is forward channel transmission characteristic, relaying crosstalk transmission characteristic and/or far-end cross talk transmission characteristic; It is characterized in that this device comprises:
One transmitting terminal processing unit links to each other with the input of described dispensing device, and it comprises:
One generator that sends test massage, its output one sends test massage; And,
One adder comprises two inputs and an output, an input termination described service signal wherein, and wherein termination is described sends test massage in another input, and described output provides the mixed signal of this service signal and test signal;
One receiving terminal processing unit links to each other with the output of described receiving system, and it comprises:
One signal processor, comprise an input and an output, wherein be input as through the transmission after service signal and the mixed signal of test signal, and in the transmission channel bandwidth with described business and test mixing transmission signal frequency spectrum frequency spectrum divided by test signal, to remove the influence of test signal frequency spectrum amplitude and phase change on the transmission channel bandwidth, obtain and provide the characteristic instantaneous estimation value of this transmission channel by described output; And,
One low pass filter, it is input as the characteristic instantaneous estimation value of transmission channel, and it is output as the characteristic mean estimates of transmission channel.
8, the measurement mechanism of characteristics of signal transmission passage as claimed in claim 7 is characterized in that, this signal processor is a deconvolution processor, and its frequency domain transmission response is the inverse of test signal frequency spectrum in the transmission channel bandwidth.
9, the measurement mechanism of transmission channel characteristics as claimed in claim 7 is characterized in that: this signal processor is a matched filter, and its time domain impulse response is the complex conjugate of the test signal of time inverted order.
10, the measurement mechanism of transmission channel characteristics as claimed in claim 7 is characterized in that: this signal processor comprises a reference signal generator and an associative processor,
This reference signal generator output one receives reference signal, and this reception reference signal is identical with the waveform that sends test massage;
This associative processor comprises two inputs and an output, wherein one be input as described reception reference signal, wherein another be input as through the transmission after service signal and the mixed signal of test signal, described output provides the characteristic instantaneous estimation value of this transmission channel.
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| CN104243376A (en) * | 2013-06-19 | 2014-12-24 | 联发科技（新加坡）私人有限公司 | Communications apparatus and related method thereof |
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| CN104243376A (en) * | 2013-06-19 | 2014-12-24 | 联发科技（新加坡）私人有限公司 | Communications apparatus and related method thereof |
| CN104243376B (en) * | 2013-06-19 | 2018-03-23 | 联发科技（新加坡）私人有限公司 | Communicator and associated method |
| CN105635004A (en) * | 2016-01-22 | 2016-06-01 | 林伟 | Detection signal operating method |
| CN106506904A (en) * | 2016-11-16 | 2017-03-15 | 浙江大华技术股份有限公司 | A kind of method for transmitting signals and equipment |
| CN106506904B (en) * | 2016-11-16 | 2019-09-17 | 浙江大华技术股份有限公司 | A kind of method for transmitting signals and equipment |
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