CN103684469A - Multichannel data acquisition method based on static periodic sequence modulation - Google Patents

Abstract

The invention discloses a multichannel data acquisition method based on static periodic sequence modulation. The multichannel data acquisition method is used for parallel low-speed acquisition of high-speed signals. The multichannel data acquisition method comprises the following specific steps that input signals are obtained from a signal receiving and channel preprocessing device; the input signals are pre-modulated through a modulation sequence, so that the pre-modulated signals in different channels are generated; lowpass filtering is conducted on the pre-modulated signal of each channel, so that lowpass signals are obtained; an analog-digital converter is applied to the lowpass signal of each channel, the lowpass signals of the channels are sampled in parallel, and therefore a base band sampled signal of each channel is obtained; a reestablishment matrix is worked out, the base band sampled signals of all the channels form a base band sampled signal matrix, reestablishment is conducted on the base band sampled signal matrix through the reestablishment matrix, and therefore a base band digital signal of each frequency band of the input signals is obtained; the base band digital signals are modulated and combined, and therefore digital sampled signals of the input signals are obtained.

Description

A kind of multi-channel data collecting method based on static periodic sequence modulation

Technical field

The present invention relates to digital signal acquiring and processing technology field, particularly a kind of multi-channel data collecting method based on static periodic sequence modulation.

Background technology

Digital communication system need to be carried out recycling digital device after digitlization to analog signal and be processed.Along with the development of modern communication technology, signal frequency, bandwidth are more and more higher, approach gradually the highest sampling rate that current single analog to digital converter (ADC) can be realized.If want, broadband signal is carried out to Direct Sampling, require ADC to there is very high sampling rate, yet the increase of ADC speed will cause the decline of its quantified precision, thereby cause the decline of dynamic range; And the stability of sampling clock also will decline along with the raising of sampling rate, this will aggravate Aperture Jitter, thereby reduce signal to noise ratio; And along with the increase of ADC speed, its cost also will sharply increase, this also will greatly improve the cost of this class digital information processing system.

At present, adopting multi-channel parallel sampling is the main flow thinking that solves single analog to digital converter (ADC) sample frequency bottleneck.Existing multi-channel parallel sampling system mainly contains three classes, one class is to use analog filter that reception broadband is divided into several subbands, recycling converter technique fades to fundamental frequency by each subband, finally adopt multichannel ADC sampling, the design of this class methods filter and frequency conversion device is complicated, realizes very difficult and error and is difficult to control; Another kind of method utilizes the relatively prime low speed ADC of a plurality of sampling rates to sample respectively to signal, finally by the regain one's integrity signal of bandwidth of difference, these class methods require the sampling rate of each passage strictly to meet relatively prime character, and this will bring great difficulty to its realization; The 3rd class methods adopt the thinking of multichannel time delay sampling, each passage is done different time delays to signal respectively, thereby rear use ADC sampling is combined into original signal, these class methods require signal to do time delay very accurately, otherwise will cause distorted signals, and for high-frequency signal, this class accurately postpones to be very difficult to accomplish.

As can be seen here, the problem that prior art exists is: how could low complex degree, low cost, stable and easily realize and realize broadband multi-channel data acquisition.

Summary of the invention

The object of the present invention is to provide a kind of multi-channel data collecting method based on static periodic sequence modulation, realization is simple, cost is low, good stability.

The technical solution that realizes the object of the invention is: a kind of multi-channel data collecting method based on static periodic sequence modulation, comprises the following steps:

10) input signal obtains: from signal reception and passage pre-processing device, obtain input signal;

20) input signal premodulated: adopt modulation sequence premodulated input signal, generate the different tonal signal in advance of each passage;

30) presetting low pass signal filtering: respectively to each passage in advance tonal signal carry out low-pass filtering, obtain low-pass signal;

40) low-pass signal sampling: respectively each passage low-pass signal is used to analog to digital converter parallel sampling, obtain each passage baseband sampling signal;

50) baseband digital signal is rebuild: according to modulation sequence and Fourier transform matrix, calculate reconstruction matrix, each passage baseband sampling signal is formed to baseband sampling signal matrix, use reconstruction matrix to rebuild baseband sampling signal matrix, obtain the baseband digital signal of each frequency band of input signal;

60) digital signal synthesis: modulate each baseband digital signal synthetic, thereby obtain the digital sampled signal of input signal.

Compared with prior art, its remarkable advantage is in the present invention:

1, realize simple: adopt conventional device, modulation sequence, generate simple, and the ADC same clock of sampling, system complexity compared with existing system reduce, realizability improves;

2, cost is low: without expensive device such as high-speed ADCs, it is low that system realizes cost;

3, computation complexity is low: the present invention rebuilds, recovery amount of calculation is low, without complexity as contour in iteration, calculates, and can realize in real time or quasi real time collection;

4, gather good stability: compare the existing collecting method based on compressed sensing, the present invention, to the no requirement (NR) of the sparse property of collection signal, without solving underdetermined equation, does not solve the risk of failure in process of reconstruction, can be stable reconstruct sampled signal;

5, applied widely: the present invention can be applicable to various data acquisition occasions, can be to carrying out undistorted collection as this type of band-limited signals such as voice, communications.

Below in conjunction with the drawings and specific embodiments, the present invention is done further and is illustrated,

Accompanying drawing explanation

Fig. 1 is the multi-channel data collecting method flow chart that the present invention is based on static periodic sequence modulation.

Fig. 2 is the multi-channel data collecting method schematic diagram that the present invention is based on static periodic sequence modulation.

Fig. 3 is that input signal is through the frequency domain schematic diagram of modulation sequence modulation.

Fig. 4 is that tonal signal obtains the frequency domain schematic diagram of low-pass signal after low-pass filtering in advance.

Fig. 5 is that baseband digital signal is moved the schematic diagram that forms digital sampled signal.

Fig. 6 is that one group of project organization parameter of the present invention is given an example.

Fig. 7, Fig. 8 are simulation result figure of the present invention.

Fig. 9 is the apparatus structure block diagram of realizing the multi-channel data collecting method that the present invention is based on static periodic sequence modulation.

In figure, 1 input signal acquiring unit, 2 input signal premodulated unit, 3 presetting low pass signal filter units, 4 low-pass signal sampling units, 5 baseband digital signal reconstruction units, 6 digital signal synthesis unit, 601 signal modulation modules, 602 signal accumulator module.

Embodiment

The flow chart that is illustrated in figure 1 the multi-channel data collecting method that the present invention is based on static periodic sequence modulation, Figure 2 shows that schematic diagram of the present invention.

As shown in Figure 1 and Figure 2, multi-channel data collecting method of the present invention comprises the following steps:

10) input signal obtains: from signal reception and passage pre-processing device, obtain input signal;

20) input signal premodulated: adopt modulation sequence premodulated input signal, generate the different tonal signal in advance of each passage;

Described each modulation sequence is comprised of code element separately respectively, the cycle is identical, code element is fixed, code element form different, chip rate is identical and the sequence of each sequence symbol synchronization.

If sampling system is m passage altogether, being sampled signal a kind of apple Qwest frequency is f _nYQ, the modulation sequence that each passage is used is comprised of code element separately respectively, and each sequence period is identical, and code element is fixed, and code element forms different, identical and each sequence symbol synchronization of chip rate.At this, take the modulation sequence that value is ± 1 is example, the modulation sequence p of i passage _i(t) be defined as:

$p_i\left(t\right)={\mathrm{\α}}_{\mathrm{ik}},k\frac{T_p}{M}\≤t\≤(k+1)\frac{T_p}{M},0\≤k\≤M-1---\left(1\right).$

F wherein _pfor modulation sequence frequency, T _pfor the modulation sequence cycle, M is modulation sequence each cycle ± 1 change number of times, and M meets M=m.α _ikvalue is+1 or-1.When m is odd number, modulation sequence frequency

when m is even number, modulation sequence frequency

order matrix P=[p ₁ ^t... p _m ^t] be modulation sequence matrix, wherein

p ₁ ^tfor p ₁go to, matrix P should be invertible matrix.Mathematical procedure from modulation sequence in frequency-domain analysis premodulated, p _i(t) Fourier series is:

$p_i\left(t\right)={\mathrm{\&Sigma;}}_{i=-\&infin;}^{\&infin;}{c}_{\mathrm{il}}{e}^{\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="HDA0000430578950000032.png,HDA0000430578950000041.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{2\mathrm{\&pi;}}{T_p}\mathrm{lt}}---\left(2\right),$

Wherein

$c_{\mathrm{il}}=\frac{1}{T_p}{\&Integral;}_0^{T_p}{p}_i\left(t\right)e^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="HDA0000430578950000032.png,HDA0000430578950000041.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{2\mathrm{\&pi;}}{T_p}\mathrm{lt}}\mathrm{dt}---\left(3\right).$

Modulation sequence p _i(t) to the modulation formula of input signal x (t), be:

x′(t)＝p _i(t)×x(t) (4),

Its Fourier transform is:

${X_i}^{\&prime;}\left(f\right)={\mathrm{\&Sigma;}}_{i=-\&infin;}^{i=\&infin;}{c}_{\mathrm{il}}X(f-{\mathrm{lf}}_p)---\left(5\right).$

By (5), can be found out, formula (5) is by the signal spectrum lf that is shifted _pand stack.As shown in Figure 3.

30) presetting low pass signal filtering: respectively to each passage in advance tonal signal carry out low-pass filtering, obtain low-pass signal;

In described presetting low pass signal filtering (30) step, the low pass filter that each passage is used is simulation low-pass filter, and each filter has identical or close amplitude-frequency, phase versus frequency response charac t.

40) low-pass signal sampling: respectively each passage low-pass signal is used to analog to digital converter parallel sampling, obtain each passage baseband sampling signal;

In described low-pass signal sampling (40) step, the analog to digital converter that each passage is used has identical sample frequency and sampling clock.

The ADC that each passage is used has identical sample frequency and sampling clock, and each passage generates baseband sampling signal y after low-pass signal is sampled _i[n].For preventing the aliasing of sampling, the sample frequency f of ADC _smeet: f _s>=f _p.

50) reconstruction matrix calculates: according to modulation sequence and Fourier transform matrix, calculate reconstruction matrix;

Described reconstruction matrix calculates (50) step and is specially:

Reconstruction matrix

C＝A ^-1＝(S×F×D) ^-1 (6)

Computational methods are as follows, the modulation sequence p of passage _i(t) be:

$p_i\left(t\right)={\mathrm{\&alpha;}}_{\mathrm{ik}},k\frac{T_p}{M}\&le;t\&le;(k+1)\frac{T_p}{M},0\&le;k\&le;M-1---\left(7\right),$

P _i(t) Fourier series is:

$p_i\left(t\right)={\mathrm{\&Sigma;}}_{i=-\&infin;}^{\&infin;}{c}_{\mathrm{il}}{e}^{\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="HDA0000430578950000032.png,HDA0000430578950000041.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{2\mathrm{\&pi;}}{T_p}\mathrm{lt}}---\left(8\right),$

$c_{\mathrm{il}}=\frac{1}{T_p}{\&Integral;}_0^{T_p}{p}_i\left(t\right)e^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="HDA0000430578950000032.png,HDA0000430578950000041.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{2\mathrm{\&pi;}}{T_p}\mathrm{lt}}\mathrm{dt}---\left(9\right),$

Modulation sequence p _i(t) to the modulation formula of input signal x (t), be:

x′(t)＝p _i(t)×x(t) (10),

Its Fourier transform is:

${X_i}^{\&prime;}\left(f\right)={\mathrm{\&Sigma;}}_{i=-\&infin;}^{i=\&infin;}{c}_{\mathrm{il}}X(f-{\mathrm{lf}}_p)---\left(11\right),$

The low-pass signal frequency spectrum of passage is:

(12) are write a Chinese character in simplified form into:

y(f)＝Az(f) (13),

$A_{\mathrm{il}}=c_{\mathrm{il}}=\frac{1}{T_p}{\mathrm{\&Sigma;}}_{k=0}^{k=M-1}{\mathrm{\&alpha;}}_{\mathrm{ik}}{e}^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="HDA0000430578950000032.png,HDA0000430578950000041.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{2\mathrm{\&pi;}}{M}\mathrm{ik}}{\&Integral;}_0^{\frac{T_p}{M}}{e}^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="HDA0000430578950000032.png,HDA0000430578950000041.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{2\mathrm{\&pi;}}{T_p}\mathrm{lt}}\mathrm{dt}=d_i{\mathrm{\&Sigma;}}_0^{k=M-1}{\mathrm{\&alpha;}}_{\mathrm{ik}}{\mathrm{\&theta;}}^{\mathrm{lk}}---\left(14\right),$

$d_l=\frac{1}{T_p}{\&Integral;}_0^{\frac{T_p}{N}}{e}^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="HDA0000430578950000032.png,HDA0000430578950000041.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{2\mathrm{\&pi;}}{T_p}\mathrm{lt}}\mathrm{dt}=\left\{\begin{array}{cc}\frac{1}{M}& l=0\\ \frac{1-{\mathrm{\&theta;}}^{\mathrm{<figure-callout\; id="2"\; label="l"\; filenames="HDA0000430578950000032.png,HDA0000430578950000041.png"\; state="\{\{state\}\}">l</figure-callout>}}}{2\mathrm{j\&pi;l}}& l\&NotEqual;0\end{array}\right.---\left(15\right),$

θ wherein ₌e ^{-j2 π/M},

Order

d=diag (d _-[m/2]..., d _[m/2]), S _ik=α _ik,

Formula (13) can be write as:

y(f)＝SFDz(f) (16),

Z (f)=(SFD) ^-1y (f).

60) baseband digital signal is rebuild: each passage baseband sampling signal is formed to baseband sampling signal matrix, use reconstruction matrix to rebuild baseband sampling signal matrix, obtain the baseband digital signal of each frequency band of input signal;

Described baseband digital signal is rebuild (60) step and is comprised:

61) according to baseband sampling signal y _i[n] forms baseband sampling signal matrix Y

62) use reconstruction matrix C premultiplication baseband sampling signal matrix Y, thereby obtain the baseband digital signal r ' of each frequency band of input signal _i[n].

By formula (6), (7), known signal matrix Y=[y ₁[n] ^t..., y _m[n] ^t] ^t, baseband digital signal matrix

R′＝CY (17)

R ' _ithe i that [n] is matrix R ' is capable.

70) input sample signal acquisition: modulate each baseband digital signal synthetic, thereby obtain the digital sampled signal of input signal.

Described input sample signal acquisition (70) step comprises:

71) each baseband digital signal r ' is moved in modulation _i[n];

72) by the cumulative digital sampled signal r[n that obtains of the signal after moving].

R[n] be the undistorted sampled signal of original signal, the effect of modulation is that each frequency spectrum baseband signal is moved go back to its frequency spectrum relevant position, its schematic diagram is as shown in Figure 5.

Fig. 6 has provided one group of design parameter example of data acquisition system of the present invention, and Fig. 7, Fig. 8 have provided two groups of results that adopt this group parameter to carry out emulation.Emulated data is the stack of a plurality of signals, and signal bandwidth is random, centre frequency is random, signal to noise ratio is random and between 5-20dB, signal Gao a kind of apple Qwest frequency is 4G.For convenience of observing, rebuild and input signal, Fig. 7, Fig. 8 have provided the frequency spectrum of original signal and collection signal, can be found out, by result in noisy situation, native system can accurately gather and recover all original signals, has verified the feasibility of the method and the stability of this system and reliability.

As shown in Figure 9, realize the device of the multi-channel data collecting method that the present invention is based on static periodic sequence modulation, comprising:

One input signal acquiring unit 1, for obtaining input signal from signal reception and passage pre-processing device;

A plurality of input signal premodulated unit 2, for adopting modulation sequence premodulated input signal, generates the different tonal signal in advance of each passage;

A plurality of presetting low pass signal filter units 3, for respectively to each passage in advance tonal signal carry out low-pass filtering, obtain low-pass signal;

A plurality of low-pass signal sampling units 4, for respectively each passage low-pass signal being used to analog to digital converter parallel sampling, obtain each passage baseband sampling signal;

One baseband digital signal reconstruction unit 5, for calculating reconstruction matrix, forms baseband sampling signal matrix by each passage baseband sampling signal, uses reconstruction matrix to rebuild baseband sampling signal matrix, obtains the baseband digital signal of each frequency band of input signal;

One digital signal synthesis unit 6, for modulating each baseband digital signal synthetic, thereby obtains the digital sampled signal of input signal;

Each passage is composed in series successively by the presetting low pass signal filter unit 3 in 2,1 of 1 input signal premodulated unit and 1 low-pass signal sampling unit 4, after a plurality of passage associations, the output of front termination input signal acquiring unit 1, rear termination baseband digital signal reconstruction unit 5, the input of the output termination digital signal synthesis unit 6 of baseband digital signal reconstruction unit 5.

Described digital signal synthesis unit 6 comprises signal modulation module 601 and 1 signal accumulator module 602 of a plurality of parallel connections, after described signal modulation module 601 parallel connections, and front termination baseband digital signal reconstruction unit 5, rear termination signal accumulator module 602.

Claims (9)

1. a multi-channel data collecting method of modulating based on static periodic sequence, is characterized in that: comprise the following steps:

10) input signal obtains: from signal reception and passage pre-processing device, obtain input signal;

20) input signal premodulated: adopt modulation sequence premodulated input signal, generate the different tonal signal in advance of each passage;

30) presetting low pass signal filtering: respectively to each passage in advance tonal signal carry out low-pass filtering, obtain low-pass signal;

40) low-pass signal sampling: respectively each passage low-pass signal is used to analog to digital converter parallel sampling, obtain each passage baseband sampling signal;

50) baseband digital signal is rebuild: calculate reconstruction matrix, each passage baseband sampling signal is formed to baseband sampling signal matrix, use reconstruction matrix to rebuild baseband sampling signal matrix, obtain the baseband digital signal of each frequency band of input signal;

60) digital signal synthesis: modulate each baseband digital signal synthetic, thereby obtain the digital sampled signal of input signal.

2. multi-channel data collecting method according to claim 1, it is characterized in that: in described input signal premodulated (20) step: described each modulation sequence is comprised of code element separately respectively, the cycle is identical, code element is fixed, code element form different, chip rate is identical and the sequence of each sequence symbol synchronization.

3. multi-channel data collecting method according to claim 1, it is characterized in that: in described presetting low pass signal filtering (30) step, the low pass filter that each passage is used is simulation low-pass filter, and each filter has identical or close amplitude-frequency, phase versus frequency response charac t.

4. multi-channel data collecting method according to claim 1, is characterized in that: in described low-pass signal sampling (40) step, the analog to digital converter that each passage is used has identical sample frequency and sampling clock.

5. multi-channel data collecting method according to claim 1, is characterized in that: described baseband digital signal is rebuild (50) step and comprised:

51) according to modulation sequence and Fourier transform matrix, calculate reconstruction matrix;

52) according to baseband sampling signal y _i[n] forms baseband sampling signal matrix Y;

53) use reconstruction matrix C premultiplication baseband sampling signal matrix Y, thereby obtain the baseband digital signal r ' of each frequency band of input signal _i[n].

6. multi-channel data collecting method according to claim 5, is characterized in that: describedly according to modulation sequence and Fourier transform matrix, calculate reconstruction matrix (51) step and be specially:

Reconstruction matrix

C＝A ^-1＝(S×F×D) ^-1 (1)

Computational methods as follows, establish the modulation sequence p of i passage _i(t) be:

$p_i\left(t\right)={\mathrm{\&alpha;}}_{\mathrm{ik}},k\frac{T_p}{M}\&le;t\&le;(k+1)\frac{T_p}{M},0\&le;k\&le;M-1---\left(2\right),$

Wherein input signal a kind of apple Qwest frequency is f _nYQ, system channel number is m, f _pfor modulation sequence frequency, T _pfor the modulation sequence cycle, M is modulation sequence each cycle ± 1 change number of times, and M meets M=m.α _ikvalue is+1 or-1.When m is odd number, modulation sequence frequency

when m is even number, modulation sequence frequency p _i(t) Fourier series is:

$p_i\left(t\right)={\mathrm{\&Sigma;}}_{i=-\&infin;}^{\&infin;}{c}_{\mathrm{il}}{e}^{j\frac{2\mathrm{\&pi;}}{T_p}\mathrm{lt}}---\left(3\right),$

Wherein

$c_{\mathrm{il}}=\frac{1}{T_p}{\&Integral;}_0^{T_p}{p}_i\left(t\right)e^{-j\frac{2\mathrm{\&pi;}}{T_p}\mathrm{lt}}\mathrm{dt}---\left(4\right).$

Modulation sequence p _i(d) to the modulation formula of input signal x (t), be:

x′(t)＝p _i(t)×x(t) (5)，

Its Fourier transform is:

${X_i}^{\&prime;}\left(f\right)={\mathrm{\&Sigma;}}_{i=-\&infin;}^{i=\&infin;}{c}_{\mathrm{il}}X(f-{\mathrm{lf}}_p)---\left(6\right),$

The low-pass signal frequency spectrum of passage i is:

(7) are write a Chinese character in simplified form into:

y(f)＝Az(f) (8)，

Wherein:

$A_{\mathrm{il}}=c_{\mathrm{il}}=\frac{1}{T_p}{\mathrm{\&Sigma;}}_{k=0}^{k=M-1}{\mathrm{\&alpha;}}_{\mathrm{ik}}{e}^{-j\frac{2\mathrm{\&pi;}}{M}\mathrm{ik}}{\&Integral;}_0^{\frac{T_p}{M}}{e}^{-j\frac{2\mathrm{\&pi;}}{T_p}\mathrm{lt}}\mathrm{dt}=d_i{\mathrm{\&Sigma;}}_0^{k=M-1}{\mathrm{\&alpha;}}_{\mathrm{ik}}{\mathrm{\&theta;}}^{\mathrm{lk}}---\left(9\right),$

$d_l=\frac{1}{T_p}{\&Integral;}_0^{\frac{T_p}{N}}{e}^{-j\frac{2\mathrm{\&pi;}}{T_p}\mathrm{lt}}\mathrm{dt}=\left\{\begin{array}{cc}\frac{1}{M}& l=0\\ \frac{1-{\mathrm{\&theta;}}^l}{2\mathrm{j\&pi;l}}& l\&NotEqual;0\end{array}\right.---\left(10\right),$

θ=e wherein ^{-j2 π/M}order d=diag (d _-[m/2]..., d _[m/2]), S _ik=α _ik, formula (8) can be write as:

(f)＝SFDz(f) (11)，

Z (f)=(SFD) ^-1y (f).

7. multi-channel data collecting method according to claim 1, is characterized in that: described input sample signal acquisition (60) step comprises:

61) each baseband digital signal r ' is moved in modulation _i[n];

62) by the cumulative digital sampled signal r[n that obtains of the signal after moving].

8. the multi-channel data collecting method based on static periodic sequence modulation according to claim 1, is characterized in that, it is by realizing as lower device, and this device comprises:

One input signal acquiring unit (1), for obtaining input signal from signal reception and passage pre-processing device;

A plurality of input signal premodulated unit (2), for adopting modulation sequence premodulated input signal, generate the different tonal signal in advance of each passage;

A plurality of presetting low pass signal filter units (3), for respectively to each passage in advance tonal signal carry out low-pass filtering, obtain low-pass signal;

A plurality of low-pass signal sampling units (4), for respectively each passage low-pass signal being used to analog to digital converter parallel sampling, obtain each passage baseband sampling signal;

One baseband digital signal reconstruction unit (5), for calculating reconstruction matrix, forms baseband sampling signal matrix by each passage baseband sampling signal, uses reconstruction matrix to rebuild baseband sampling signal matrix, obtains the baseband digital signal of each frequency band of input signal;

One digital signal synthesis unit (6), for modulating each baseband digital signal synthetic, thereby obtains the digital sampled signal of input signal;

Each passage is composed in series successively by 1 input signal premodulated unit (2), 1 presetting low pass signal filter unit (3) and 1 low-pass signal sampling unit (4), after a plurality of passage associations, the output of front termination input signal acquiring unit (1), rear termination baseband digital signal reconstruction unit (5), the input of the output termination digital signal synthesis unit (6) of baseband digital signal reconstruction unit (5).

9. multi-channel data collecting method according to claim 8, it is characterized in that: described digital signal synthesis unit (6) comprises signal modulation module (601) and 1 signal accumulator module (602) of a plurality of parallel connections, after described signal modulation module (601) parallel connection, front termination baseband digital signal reconstruction unit (5), rear termination signal accumulator module (602).

Images