WO2015096094A1

WO2015096094A1 - Modulation of signal and recovery method of digital information, communication device and system

Info

Publication number: WO2015096094A1
Application number: PCT/CN2013/090569
Authority: WO
Inventors: 罗小东; 冯志勇; 何俊
Original assignee: 华为技术有限公司
Priority date: 2013-12-26
Filing date: 2013-12-26
Publication date: 2015-07-02
Also published as: CN104904173B; CN104904173A

Abstract

　Provided is a communication device, comprising: a first pilot frequency occurrence module for loading digital information to a carrier signal so as to generate a first pilot frequency signal, wherein the frequency of the carrier signal is f₁; a second pilot frequency occurrence module for generating a second pilot frequency signal which is not loaded with digital information, wherein the frequency of the second pilot frequency signal is f₂, f₂≠f₁; an adder for adding the first pilot frequency signal and the second pilot frequency signal so as to generate a total pilot frequency signal; and a modulator for modulating the total pilot frequency signal into a signal needing to be loaded with a pilot frequency so as to obtain a signal loaded with the pilot frequency. Further provided are a method and system of digital information, and by way of the present invention, a judgement threshold can be calculated in real time, the digital information can be recovered and network time delay can be reduced.

Description

One by one

Signal modulation and digital information recovery method, communication device and system

The present invention relates to the field of communications, and in particular, to a signal modulation, digital information recovery method, communication device and system. Background technique

With the large-scale application of WDM networks, in order to implement performance monitoring of WDM networks, a WDM optical network status monitoring method based on pilot signals has emerged, specifically: modulating a unique pilot signal with a unique frequency on each wavelength channel for identification After using a beam splitter to receive a small portion of the optical signal from the photodetector on the link or in the wavelength feedthrough node, the pilot signal is detected to identify the corresponding wavelength, and the optical power of the corresponding wavelength channel is calculated. In order to enhance the ability of the pilot signal to transmit information, a method of digitally modulating the pilot signal occurs, and the pilot detection signal demodulates the modulated pilot signal to recover the transmitted digital information. Since the pilot signal modulated on the optical signal is relatively weak, the amount of alternating current of the pilot signal and the direct current of the optical signal will be less than 5%, and the signal-to-noise ratio SNR of the pilot signal is very small.

In order to effectively recover the digital information modulated on the pilot signal, the prior art adopts a scheme: sampling a pilot signal carrying digital information by using a FFT window of a certain length, and then determining a sampling value by a threshold, and recovering according to the algorithm. The digital information modulated on the pilot signal. For the calculation of the decision threshold, because of the ASK modulation method, there is a symbol 0 in the digital information. When the symbol 0 appears, it means that there is no pilot. Only when the symbol 1 appears, the pilot can be detected. Therefore, the decision threshold is calculated. It is necessary to determine a certain number of symbols 1 for a relatively long period of time, and the decision threshold can be calculated based on the noise level and the pilot strength on symbol 1. In a WDM network, a pilot detection node monitors fiber links of multiple dimensions. Therefore, the input fiber of the pilot detection is switched in real time, so that the requirement for real-time detection is very high, and the method for calculating the threshold is not satisfied. Real-time requirements. Summary of the invention

The embodiment of the invention provides a signal modulation and digital information recovery method, a communication device and a system, which can utilize the dual pilot signals carried in the signal to calculate the decision threshold in real time, thereby improving the calculation efficiency of recovering digital information, and reducing the time. Delay. The first aspect of the embodiment of the present invention provides a communication device, including:

a first pilot generating module, configured to load digital information onto the carrier signal to generate a first pilot signal, where the frequency of the carrier signal is

a second pilot generating module, configured to generate a second pilot signal that is not loaded with digital information, where the frequency of the second pilot signal is f ₂ , f ₂ ≠ f _x ;

An adder, configured to add the first pilot signal and the second pilot signal to generate a total pilot signal modulator, configured to modulate the total pilot signal into a signal to be loaded with a pilot, Get the signal loaded with the pilot.

In combination with the first aspect, in the first possible implementation manner, the method further includes:

And a frequency allocation module, configured to select, according to a preset pilot frequency allocation table, the f ₂ and the second pilot signal respectively allocated to the carrier signal.

In conjunction with the first aspect or the first possible implementation, in a second possible implementation, the maximum amplitude of the carrier signal is equal or proportional to the maximum amplitude of the second pilot signal.

A second aspect of the embodiments of the present invention provides a communications device, including:

a first filtering module, configured to filter a signal loaded with a pilot to obtain a first pilot signal, where the first pilot signal is generated by loading digital information onto a carrier signal, and the frequency of the carrier signal is f

a second filtering module, configured to perform filtering processing on the pilot-loaded signal to obtain a second pilot signal, where the second pilot signal does not carry digital information, and the frequency of the second pilot signal is f ₂ , i ₂ 1 ₁ ,

a first analog-to-digital conversion module, configured to perform analog-to-digital conversion on the first pilot signal to obtain first digital information;

a second analog-to-digital conversion module, configured to perform analog-to-digital conversion on the second pilot signal to obtain second digital information;

And a digital information recovery module, configured to calculate a decision threshold according to the second digital information, and recover the digital information from the first digital information by using the threshold.

With reference to the second aspect, in a first possible implementation, the pilot-loaded signal is an electrical signal carrying a pilot, and the communications device further includes:

a photoelectric conversion module, configured to filter before the first filtering module and the second filtering module - Converting the pilot-loaded optical signal to the pilot-loaded electrical signal.

In conjunction with the first possible implementation of the second aspect, in a second possible implementation manner, the method further includes:

And an amplification module, configured to perform an isolated DC and amplitude amplification process on the pilot-loaded electrical signal, and then input to the first filtering module and the second filter module.

With reference to any one of the second aspect to the second possible implementation, in a third possible implementation, the maximum amplitude of the carrier signal is equal or proportional to the maximum amplitude of the second pilot signal relationship.

In conjunction with the third possible implementation of the second aspect, in a fourth possible implementation, the sampling frequency of the second analog-to-digital conversion module is less than 2 f ₂ .

With reference to any one of the second aspect to the fourth possible implementation, in a fifth possible implementation, the digital information is a binary sequence, and the digital information recovery module includes:

a first FFT unit, configured to perform fast Fourier transform FFT processing on the first digital information to obtain a first frequency domain sequence;

a second FFT unit, configured to perform FFT processing on the second digital information to obtain a second frequency domain sequence 歹¹ J;

a first power calculation unit, configured to calculate a first signal power corresponding to a frequency in the first frequency domain sequence;

a second power calculation unit, configured to calculate a second signal power and a signal to noise ratio corresponding to the frequency f ₂ in the second frequency domain sequence;

a threshold calculation unit, configured to calculate a decision threshold according to the second signal power and the signal to noise ratio;

And a digital information recovery unit, configured to recover the digital information after determining the first signal power according to the decision threshold.

In conjunction with the fifth possible implementation of the second aspect, in a sixth possible implementation, the threshold calculation unit is configured to calculate the decision threshold according to a formula Ρ _ώ = k ² * (P ₂ - M *, Where k is the ratio of the maximum amplitude of the carrier signal to the maximum amplitude of the second pilot signal, which is a decision threshold, ^P 2 is the second signal power, and ^N 2 is the second pilot signal Noise power, M is a constant, 0 < M <1;

The digital information recovery unit is configured to: if the first signal power Ρ, > Ρ, the first letter - The decision of the power corresponding bit is 1 and if P^, the decision is 0.

A third aspect of the embodiments of the present invention provides a method for modulating a signal, including:

Loading the digital information onto the carrier signal to generate a first pilot signal, the carrier signal having a frequency of

Generating a second pilot signal without loading digital information, the frequency of the second pilot signal being f ₂ , f ₂ working 1,

Adding the first pilot signal and the second pilot signal to generate a total pilot signal;

The total pilot signal is modulated into a signal to be loaded with a pilot to obtain a pilot-loaded signal. With reference to the third aspect, in the first possible implementation, before the step of loading the digital information into the carrier signal to generate the first pilot signal, the method further includes:

The sum and the 4 are respectively assigned to the carrier signal and the second pilot signal from a preset pilot frequency allocation table.

In conjunction with the third aspect or the first possible implementation, in a second possible implementation, the maximum amplitude of the carrier signal is equal or proportional to the maximum amplitude of the second pilot signal.

A fourth aspect of the present invention provides a method for recovering digital information, including:

Filtering the signal loaded with the pilot to obtain a first pilot signal, where the first pilot signal is generated by loading digital information onto the carrier signal, and the frequency of the carrier signal is

Performing filtering processing on the pilot-loaded signal to obtain a second pilot signal, where the second pilot signal does not carry digital information, and the frequency of the second pilot signal is f ₂ , f ₂ ≠ f _{1 ;}

Performing analog-to-digital conversion on the first pilot signal to obtain first digital information;

Performing analog-to-digital conversion on the second pilot signal to obtain second digital information;

Determining a decision threshold based on the second digital information, and recovering the digital information from the first digital information by using the decision threshold.

With reference to the fourth aspect, in a first possible implementation, the pilot-loaded signal is an electrical signal loaded with a pilot, and the pilot-loaded signal is filtered to obtain a first pilot signal. Before the steps, it also includes:

The pilot-loaded optical signal is converted to the pilot-loaded electrical signal.

In conjunction with the fourth aspect or the first possible implementation, in a second possible implementation, the maximum amplitude of the carrier signal is equal or proportional to the maximum amplitude of the second pilot signal.

Combining any of the fourth aspect to the second possible implementation, in a third possible implementation In the mode, the step of converting the second pilot signal into the second digital information comprises: performing undersampling processing on the second pilot signal to obtain second digital information, where the sampling frequency is less than

2 f ₂ .

With reference to the third possible implementation of the fourth aspect, in a fourth possible implementation, the digital information is a binary sequence, and the determining a threshold is calculated according to the second digital information, and using the The step of recovering the digital information from the first digital information by the threshold includes:

Performing fast Fourier transform FFT processing on the first digital information to obtain a first frequency domain sequence; performing FFT processing on the second digital information to obtain a second frequency domain sequence;

Calculating a first signal power corresponding to the frequency in the first frequency domain sequence;

Calculating a second signal power and a signal to noise ratio corresponding to the frequency f ₂ in the second frequency domain sequence; calculating a decision threshold according to the second signal power and the signal to noise ratio;

And determining the digital signal according to the decision threshold to recover the digital information. With reference to the fourth possible implementation manner of the fourth aspect, in a fifth possible implementation, the determining, by using the second signal power and the signal to noise ratio, a decision threshold; The step of recovering the digital information after the first signal power is determined includes:

Calculating the decision threshold according to the formula P _fh = k ² * (P ₇ - M * ), where k is the carrier

² N ₂

The ratio of the maximum amplitude of the signal to the maximum amplitude of the second pilot signal is a decision threshold, which is the second signal power, ^Ν 2 is the noise power of the second pilot signal, Μ is a constant, 0 < Μ <1;

If the first signal power >, the bit corresponding to the first signal power is determined as

1 , If , the verdict is 0.

A fifth aspect of the embodiments of the present invention provides a communication device, including a processor and a memory, where the memory stores a set of program codes, and the processor calls the program code stored in the memory to perform the following operations:

Adding the first pilot signal and the second pilot signal to generate a total pilot signal; - - modulating the total pilot signal into a signal to be loaded with a pilot to obtain a pilot-loaded signal. With reference to the fifth aspect, in a first possible implementation manner, the processor is further configured to: select, according to a preset pilot frequency allocation table, the sum and the respectively allocated to the carrier signal, and Second pilot signal.

In conjunction with the fifth aspect or the first possible implementation, in a second possible implementation, the maximum amplitude of the carrier signal is equal or proportional to the maximum amplitude of the second pilot signal.

A sixth aspect of the embodiments of the present invention provides a communication device, including a processor and a memory, where the memory stores a set of program codes, and the processor calls the program code stored in the memory to perform the following operations:

With reference to the sixth aspect, in a first possible implementation, the pilot-loaded signal is an electrical signal carrying a pilot, and the processor is further configured to:

In conjunction with the sixth aspect or the first possible implementation, in a second possible implementation, the maximum amplitude of the carrier signal is equal or proportional to the maximum amplitude of the second pilot signal.

With reference to any one of the sixth aspect to the second possible implementation manner, in a third possible implementation manner, the processor performs the analog-to-digital conversion on the second pilot signal to obtain a second The steps of digital information include:

Performing under-sampling processing on the second pilot signal to obtain the second digital information, the sampling frequency is less than 2 f ₂ .

With reference to the third possible implementation manner of the sixth aspect, in a fourth possible implementation, the digital information is a binary sequence, and the processor performs the calculating a threshold according to the second digital information, And recovering the digital information from the first digital information by using the threshold The steps include:

And determining the digital signal according to the decision threshold to recover the digital information. With reference to the fourth possible implementation manner of the sixth aspect, in a fifth possible implementation, the processor is further configured to perform the calculating a threshold according to the second signal power and the signal to noise ratio And the step of restoring the digital information after determining the first signal power according to the determining threshold includes:

Calculating the decision threshold according to the formula P _th = k ² * (P ₂ - M * ^), where k is the carrier

N ₂

If the first signal power is > p _th , the bit corresponding to the first signal power is judged to be 1, if the decision is 0.

A seventh aspect of the embodiments of the present invention provides a communication system, including any one of the foregoing communication devices.

Embodiments of the present invention have the following beneficial effects:

Generating, at the transmitting end, the first pilot signal by digitally modulating the carrier signal with digital information, and generating an unmodulated second pilot signal, modulating the first pilot signal and the second pilot signal onto the input signal The receiving end can calculate the decision threshold according to the second pilot signal in real time, and recover the digital information modulated in the first pilot signal by using the decision threshold, thereby solving the problem that the calculation threshold threshold waiting time is long and the efficiency is not high. DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings to be used in the embodiments will be briefly described below. Obviously, the drawings in the following description are merely - Some embodiments of the present invention, other drawings may be obtained from those of ordinary skill in the art without departing from the drawings.

1 is a schematic structural diagram of a communication device according to a first embodiment of the present invention;

2 is a schematic diagram of frequency distribution in the pilot frequency allocation table of FIG. 1;

3 is another schematic structural diagram of a communication device according to a second embodiment of the present invention;

4 is a schematic structural diagram of a communication device according to a third embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a communication device according to a fourth embodiment of the present invention; FIG.

6 is a schematic structural diagram of the digital information recovery module of FIG. 5;

FIG. 7 is a schematic structural diagram of a communication device according to a fifth embodiment of the present invention; FIG.

FIG. 8 is a schematic flowchart diagram of a signal modulation method according to an embodiment of the present invention; FIG.

FIG. 9 is a schematic flowchart diagram of a method for restoring digital information according to an embodiment of the present invention; FIG. 10 is a schematic flowchart of a specific process of S205 in FIG. detailed description

BRIEF DESCRIPTION OF THE DRAWINGS The technical solutions in the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative work are within the scope of the present invention.

1 is a schematic structural diagram of a communication device according to a first embodiment of the present invention. In this embodiment, the communication device includes: a first pilot generation module 10, a second pilot generation module 11, and an addition. 12 and modulator 13.

The first pilot generating module 10 is configured to load digital information onto the carrier signal to generate a first pilot signal, where the frequency of the carrier signal is .

Specifically, the digital information is a binary sequence, and the first pilot signal is generated by performing 2ASK modulation on the carrier signal by using digital information, and the carrier signal is a sinusoidal signal or a cosine signal, and its frequency.

For example, suppose the carrier signal is A*cos(2 r * ft), A is the maximum amplitude of the carrier signal, and the binary sequence s(t) = J _n g(t - nT _s ), where T _s is in the digital information The symbol duration, where n is the length of the binary sequence, and a _n is the level of the nth symbol, 0 or 1, then the first pilot signal e _2ASK = A* cos(2 r * nT _s ). - a second pilot generating module 11 for generating a second pilot signal without digital information, the frequency of the second pilot signal being f ₂ , f ₂ ≠ _fl .

Specifically, the continual pilot generation module 11 generates an unmodulated second pilot signal having a frequency of f ₂ , and the second pilot signal is preferably a sinusoidal signal or a cosine signal. For example, the second pilot signal is B*. Cos(2^* f ₂ *t), B is the maximum amplitude of the second pilot signal.

The maximum amplitude of the first pilot signal is equal or proportional to the maximum amplitude of the second pilot signal, the maximum amplitude of which is specified by the communication protocol common to both the transmitting end and the receiving end.

For example, the carrier signal A*cos(2r*ft) and the second pilot signal B*cos(2r*f ₂ *t) , =8 or eight=1^*:8, Κ are constants greater than zero.

The adder 12 is configured to add the first pilot signal and the second pilot signal to generate a total pilot signal.

Specifically, the adder 12 adds the first pilot signal generated by the first pilot generating module 10 and the second pilot signal generated by the continuous pilot signal generating module 11 to obtain a total pilot signal, and the adder can be a digital addition method. Or analog adder. Taking the first pilot signal and the second pilot signal generated as an example, the total pilot signal e = A*cos(2r* f G

- nT _s ) + B*cos(2r* f ₂ *t). The modulator 13 is configured to load the pilot signal into the signal of the pilot signal to obtain a pilot-loaded signal.

Specifically, the modulator modulates the total pilot signal into the signal to be loaded with the pilot to obtain a signal that matches the characteristics of the current channel. For example, in the optical communication system, the total pilot signal is loaded into the optical signal to obtain a suitable signal. A signal transmitted in an optical fiber; in a wireless communication system, a total pilot signal is loaded onto a high frequency carrier to obtain a signal suitable for transmission in a wireless channel.

Preferably, in the optical communication system, the mode of the optical modulation may use any one of direct modulation, intra-cavity modulation and extra-cavity modulation to modulate the total pilot signal into the optical signal, and generate the pilot-loaded optical signal. The communication device of this embodiment further includes a frequency allocation module 14.

The frequency allocation module 14 is configured to select two unused frequencies from the preset pilot frequency allocation table to be respectively allocated to the carrier signal and the second pilot signal.

Specifically, the frequency stored in the preset pilot frequency allocation table is divided into two pilot bands, which are a first pilot band and a second pilot band, respectively, and the first pilot band and the second pilot band do not overlap. The first pilot band is distributed with a plurality of frequencies to be allocated to the carrier signal, and the second pilot band is distributed with a plurality of frequencies to be allocated to the second pilot signal, and the frequency assigned to the carrier signal and the second pilot are allocated. The frequency of the signal is not - - Equal, the frequencies in the first pilot band and the second pilot band carry identification information indicating their usage status.

For example, a schematic diagram of the frequency distribution in the pilot frequency allocation table shown in FIG. 2, the frequency dividing the first pilot band a and the second pilot band b, the frequency in the first pilot band a is assigned to the carrier signal, and the second pilot band b The frequency in the second pilot signal is allocated to the second pilot signal. The first pilot frequency band a is composed of N frequencies, respectively f _al , f _a2 , f _a3 ... f _aN , and the second pilot frequency band b is composed of N frequencies, respectively Is f _bl , f _b2 , f _b3 〜 f _bN , where N is a positive integer. The frequency of the first pilot band a may be lower than the frequency in the second pilot band b or higher than the frequency in the second pilot band b. The frequency interval of the first pilot band a is df _a , and the frequency interval of the second pilot band b is df _b , preferably, df _a > df _b .

Optionally, the usage status of the frequency in the pilot frequency allocation table may be represented by a Bitmap, for example, 1 indicates that the frequency has been used, and 0 indicates that the frequency is not used. The frequency allocation module 14 selects an unused frequency from the first pilot band as the frequency of the carrier signal, and selects the unused frequency f ₂ as the frequency of the second pilot signal from the second pilot band.

Implementing an embodiment of the present invention, generating a first pilot signal by loading digital information onto a carrier signal at a transmitting end, and generating a second pilot signal without loading digital information, the first pilot signal and the second pilot The signal is added to generate a total pilot signal, and the total pilot signal is modulated onto the signal to be loaded with the pilot, so that the receiving end calculates the decision threshold according to the second pilot signal in real time, and the first pilot is recovered by using the threshold. The digital information modulated in the signal solves the problem that the prior art calculation threshold threshold waiting time is long and the efficiency is not high.

3 is a schematic structural diagram of a communication device according to a second embodiment of the present invention. The following device is referred to as communication 1. The communication device 1 includes a processor 61, a memory 62, an input device 63, and an output device 64, which are in the communication device 1. The number of processors 61 may be one or more, and FIG. 3 takes a processor as an example. In some embodiments of the present invention, the processor 61, the memory 62, the input device 63, and the output device 64 may be connected by a bus or other means, and the bus connection is exemplified in FIG.

The memory 62 stores a set of program codes, and the processor 61 is configured to call the program code stored in the memory 62 for performing the following operations:

Adding the first pilot signal and the second pilot signal to generate a total pilot signal; - - modulating the total pilot signal into a signal to be loaded with a pilot to obtain a pilot-loaded signal. In some embodiments of the present invention, the carrier signal is a sinusoidal signal or a cosine signal, the digital information loaded on the carrier signal is a binary sequence, and the processor 61 performs the loading of the digital information onto the carrier signal. The steps of generating the first pilot signal include:

Binary amplitude keying of the sinusoidal or cosine signal using the binary sequence

The 2ASK modulation generates the first pilot signal.

In some embodiments of the present invention, the processor 61 is further configured to:

And selecting the sum and the respectively assigned to the carrier signal and the second pilot signal from a preset pilot frequency allocation table.

In some embodiments of the invention, the maximum amplitude of the carrier signal is equal or proportional to the maximum amplitude of the second pilot signal.

In some embodiments of the invention, the processor 61 executes

The step of modulating the total pilot signal into a signal to be loaded with a pilot to obtain a pilot-loaded signal includes:

The total pilot signal is modulated into the optical signal to obtain a pilot-loaded optical signal; wherein the modulation method includes any one of direct modulation, intracavity modulation, and extracavity modulation.

4 is a schematic structural diagram of a communication device according to a third embodiment of the present invention. In this embodiment, the recovery device includes a first filtering module 20, a second filtering module 21, and a first analog-to-digital conversion module 22. The second analog to digital conversion module 23 and the digital information recovery module 24.

The first filtering module 20 is configured to perform filtering processing on the signal loaded with the pilot to obtain a first pilot signal, where the first pilot signal is generated by loading digital information onto the carrier signal, and the frequency of the carrier signal is .

Specifically, the first filtering module 20 can be implemented by using a center frequency as a band pass filter, and the signal loaded with the pilot is filtered by the first filtering module 20, and the first pilot signal is obtained after suppressing out-of-band noise of the first pilot signal. .

a second filtering module 21, configured to perform filtering processing on the pilot-loaded signal to obtain the second pilot signal, where the second pilot signal does not carry digital information, and the second pilot signal frequency

^ ^ is f 2, f 2 ^ f 1.

Specifically, the second filtering module 21 can be implemented by a band pass filter having a center frequency of f ₂ , and the signal loaded with the pilot is filtered by the second filtering module 21 to suppress out-of-band noise of the second pilot signal. - - After getting the second pilot signal.

The first analog-to-digital conversion module 22 is configured to perform analog-to-digital conversion on the first pilot signal to obtain a first pilot sequence.

Specifically, the first analog-to-digital conversion module 22 performs time domain sampling on the first pilot signal to obtain a first pilot sequence, and the sampling frequency of the first analog-to-digital conversion module 22 is greater than the Nyquist sampling frequency, that is, the sampling frequency is greater than ^f. i, the length of each sample is the symbol duration of a digital information, for example, the symbol duration is T _s , the subsequent examples are all for the decision method of the bit duration of one symbol, other bits The decision method of the bit is adopted by this method.

The second analog-to-digital conversion module 23 is configured to perform analog-to-digital conversion on the second pilot signal to obtain a second pilot sequence.

Specifically, the second analog-to-digital conversion module 23 performs time domain sampling on the second pilot signal to obtain a second pilot sequence. Since the second pilot signal is an unmodulated single frequency signal, the sampling frequency offset is smaller than the Nyquist. The sampling frequency can also recover the second pilot signal without distortion, that is, undersampling the second pilot signal to obtain a second pilot sequence, the sampling frequency is less than 2 f ₂ , and the length of each sampling is not limited, and can also be T _s , this can effectively reduce the amount of calculation.

The digital information recovery module 24 is configured to calculate a decision threshold according to the second pilot sequence, and recover the digital information from the first pilot sequence by using the threshold.

Specifically, the digital information recovery module 24 performs discrete Fourier transform DFT processing on the first pilot sequence to obtain a corresponding first frequency domain sequence, and calculates a corresponding signal power on the frequency from the first frequency domain sequence, and the signal power is obtained. As the data to be judged.

Optionally, the first analog-to-digital conversion module 22 and the second analog-to-digital conversion module 23 can be implemented by an ADC (Analog to Digital Converter), and the first pilot signal is respectively used by the two sampling channels of the ADC. The sampling with the second pilot signal can also be implemented by two ADCs, which is not limited in the present invention.

The digital information recovery module 24 performs a discrete Fourier transform DFT on the second frequency domain sequence to obtain a second frequency domain sequence, and calculates corresponding signal power and noise power at each frequency point from the second frequency domain sequence, according to the transmitting end and The communication protocol at the receiving end acquires the relationship between the maximum amplitude of the carrier signal and the maximum amplitude of the second pilot signal, calculates a decision threshold according to the maximum amplitude relationship between the signal power and the noise power meter, and uses the decision threshold to determine the decision data, if the data to be determined is to be determined If it is greater than the decision threshold, the judgment is 1 and the judgment is 0. This determines the frequency domain sequence of each sample and restores the second guide. - - Digital information modulated in the frequency signal.

In an embodiment of the present invention, the receiving end can calculate the decision threshold according to the second pilot signal in real time, and recover the digital information modulated in the first pilot signal by using the threshold, thereby solving the long waiting time for calculating the decision threshold, and the efficiency is not High deficiency.

5 and FIG. 6 is a schematic structural diagram of a communication device according to a fourth embodiment of the present invention. In this embodiment, the communication device includes a first filtering module 20 and a second filtering module 21, In addition to the first analog to digital conversion module 22, the second analog to digital conversion module 23, and the digital information recovery module 24, a photoelectric conversion module 25 and an amplification module 26 are further included.

The photoelectric conversion module 25 is configured to convert the pilot-loaded optical signal into a pilot-loaded electrical signal.

Specifically, the photoelectric conversion module 20 converts the input pilot-loaded optical signal into an electrical signal, and the photoelectric conversion module 25 can realize photoelectric conversion by the photodetector. The pilot light signal is pre-modulated at the transmitting end with a total pilot signal generated by adding the first pilot signal and the second pilot signal, and the first pilot signal is digitally modulated by the digital information to the carrier signal of the frequency The second pilot signal is generated as an unmodulated single frequency signal having a frequency f ₂ , and the maximum amplitude of the carrier signal and the maximum amplitude of the second pilot signal are equal or fixed proportional relationship.

The amplifying module 26 is configured to perform an isolated DC and amplitude amplification process on the pilot-loaded electrical signal, and then input to the first filtering module and the second filter module.

Specifically, the amplification module 26 suppresses the DC component in the electrical signal, and simultaneously amplifies the AC component therein and inputs the first filtering module 21 and the second filtering module 22.

The optical power calculation module 26 is configured to calculate optical power of the dimmed signal according to the second frequency domain sequence.

Optionally, the digital information recovery module 24 includes a first FFT unit 241, a second FFT unit 242, a first power calculation unit 243, a second power calculation unit 244, a threshold calculation unit 245, and a digital information recovery unit 246.

The first FFT unit 241 is configured to perform fast Fourier transform FFT processing on the first pilot sequence to obtain a first frequency domain sequence.

The second FFT unit 242 is configured to perform FFT processing on the second pilot sequence to obtain a second frequency domain sequence.

a first power calculation unit 243, configured to calculate a frequency f in the first frequency domain sequence, corresponding to the first - - Signal power.

a second power calculation unit 244, configured to calculate a second signal power and a signal to noise ratio corresponding to the frequency f ₂ in the second frequency domain sequence;

The threshold calculation unit 245 is configured to calculate a decision threshold according to the second signal power and the signal to noise ratio.

The digital information restoring unit 246 is configured to recover the digital information after determining the first signal power according to the decision threshold.

Optionally, the threshold calculation unit 245 is configured to calculate the method according to the formula P _fh = k ² * (P ₇ - M * )

N ₂

a decision threshold, where k is a ratio of a maximum amplitude of the carrier signal to a maximum amplitude of the second pilot signal, and is a decision threshold, which is the second signal power, where ^N2 is the second pilot signal Noise power, M is a constant, 0 < M < 1, preferably, M = 0.5.

The digital information restoring unit 246 is configured to: if the first signal power > Ρ _ώ , the bit corresponding to the first signal power has a decision of 1, and if Pth, the decision is 0.

7 is a schematic structural diagram of a communication device according to a fifth embodiment of the present invention. The following device is referred to as a communication device 2. The communication device 2 includes a processor 71, a memory 72, an input device 73, and an output 7 64. The recovery device 2 The number of processors 61 in the process may be one or more, and FIG. 7 takes a processor as an example. In some embodiments of the present invention, the processor 71, the memory 72, the input device 73, and the output device 74 may be connected by a bus or other means, and the bus connection is taken as an example in FIG.

The memory 72 stores a set of program codes, and the processor 71 is configured to call the program code stored in the memory 72 for performing the following operations:

Performing a filtering process on the pilot-loaded signal to obtain the second pilot signal, where the second pilot signal does not carry digital information, and the frequency of the second pilot signal is f ₂ , f ₂ ≠ f _x ;

Performing analog-to-digital conversion on the first pilot signal to obtain a first pilot sequence;

Performing analog-to-digital conversion on the second pilot signal to obtain a second pilot sequence;

Determining a decision threshold based on the second pilot sequence and recovering the digital information from the first pilot sequence using the decision threshold.

In some embodiments of the invention, the pilot loaded signal is an electrical signal loaded with a pilot. - The processor 71 is also used to execute:

In some embodiments of the invention, the processor 71 is further configured to:

Performing a tens of thousands of direct current and amplitude amplification processing on the pilot-loaded electrical signal.

In some embodiments of the present invention, the step of the processor 71 performing the analog-to-digital conversion on the second pilot signal to obtain a second pilot sequence includes:

Performing under-sampling on the second pilot signal to obtain a second pilot sequence having a sampling frequency less than 2 f ₂ .

In some embodiments of the present invention, the processor 71 performs the calculating a threshold according to the second pilot sequence, and recovering the digital information from the first pilot sequence by using the threshold. The steps include:

Performing fast Fourier transform FFT processing on the first pilot sequence to obtain a first frequency domain sequence; performing FFT processing on the second pilot sequence to obtain a second frequency domain sequence;

And determining the digital signal according to the decision threshold to recover the digital information. In some embodiments of the present invention, the processor 71 performs the determining a threshold according to the second signal power and the signal to noise ratio; and determining the first signal power according to the threshold The steps of recovering the digital information include:

² N ₂

If the first signal power is > p _th , the bit corresponding to the first signal power is determined as

1 , If , the verdict is 0.

Referring to FIG. 8, a schematic flowchart of a signal modulation method according to an embodiment of the present invention is shown in FIG. - In the example, the modulation method comprises:

5101. Load digital information onto a carrier signal to generate a first pilot signal.

Specifically, the digital information is a binary sequence, and the frequency of the carrier signal is: the first pilot signal is generated by 2ASK modulation of the carrier signal by using digital information, and the carrier signal is a sinusoidal signal or a cosine signal, and its frequency.

For example, suppose the carrier signal is cos(2 r * ft) and the digital information s(t) = J a _n g(t - nT _s ), where T _s is the symbol duration in the digital information, and n is the digital information The length of ^{n n} _n is the value of the nth symbol, 0 or 1, then the first pilot signal 6 ₂ = ((^2 ^

- nT _s

5102. Generate a second pilot signal that does not load digital information. ⁿ

Specifically, an unmodulated second pilot signal having a frequency of f _{2 is} generated, and the second pilot signal is preferably a sinusoidal signal or a cosine signal. For example, the second pilot signal is cos(2 r * f ₂ * t

The maximum amplitude of the second pilot signal is equal to or in a fixed proportional relationship with the maximum amplitude of the second pilot signal, and the maximum amplitude of the two is specified by a communication protocol common to both the transmitting end and the receiving end.

5103. Add the first pilot signal and the second pilot signal to generate a total pilot signal. S104. Modulate the total pilot signal into a signal to be loaded with a pilot to obtain a pilot-loaded signal.

Specifically, the total pilot signal is modulated into a signal to be loaded with a pilot to obtain a signal matching the current channel characteristic. For example, in an optical communication system, the total pilot signal is loaded into the optical signal to obtain a suitable optical fiber. The signal transmitted in the wireless communication system, the total pilot signal is loaded onto the high frequency carrier to obtain a signal suitable for transmission in the wireless channel.

Preferably, in the optical communication system, the mode of the optical modulation may use any one of direct modulation, intra-cavity modulation and extra-cavity modulation to modulate the total pilot signal into the optical signal, and generate the pilot-loaded optical signal. In this embodiment, before S101, the method further includes the step of selecting, from the preset pilot frequency allocation table, two unused frequencies to be allocated to the carrier signal and the second pilot signal.

Specifically, the frequency stored in the preset pilot frequency allocation table is divided into two pilot bands, which are a first pilot band and a second pilot band, respectively, and the first pilot band and the second pilot band do not overlap. The first pilot band is distributed with a plurality of frequencies to be allocated to the carrier signal, and the second pilot band is distributed with a plurality of frequencies to be allocated to the second pilot signal, and the frequency assigned to the carrier signal and the second pilot are allocated. The frequencies of the signals are not equal, and the frequencies in the first pilot band and the second pilot band carry identification information indicating their use status. - - For example, a schematic diagram of the distribution of frequencies in the pilot frequency allocation table shown in FIG. 2, the frequency dividing the first pilot band a and the second pilot band b, the frequency in the first pilot band a being assigned to the carrier signal, the second guide The frequency in the frequency band b is allocated to the second pilot signal, and the first pilot frequency band a is composed of N frequencies, respectively f _al , f _a2 , f _a3 ... f _aN , and the second pilot frequency band b is composed of N frequencies , respectively, f _bl , f _b2 , f _b3 〜 f _bN , where N is an integer. The frequency of the first pilot band a may be lower than the frequency in the second pilot band b or higher than the frequency in the second pilot band b. The frequency interval of the first pilot band a is df _a , and the frequency interval of the second pilot band b is df _b , preferably, df _a > df _b .

Optionally, the usage status of the frequency in the pilot frequency allocation table may be represented by a Bitmap, for example, 1 indicates that the frequency has been used, and 0 indicates that the frequency is not used. The unused frequency fl is selected as the frequency of the carrier signal from the first pilot band, and the unused frequency f2 is selected as the frequency of the second pilot signal from the second pilot band.

FIG. 9 is a schematic flowchart of a method for restoring digital information according to an embodiment of the present invention. In this embodiment, the recovery method includes:

5201. Perform filtering processing on the signal loaded with the pilot to obtain a first pilot signal, where the first pilot signal is generated by loading digital information onto the carrier signal.

5202. Perform filtering processing on the pilot-loaded signal to obtain a second pilot signal, where the second pilot signal does not carry digital information.

S203. Perform analog-to-digital conversion on the first pilot signal to obtain a first pilot sequence.

S204. Perform analog-to-digital conversion on the second pilot signal to obtain a second pilot sequence.

S205. Calculate a decision threshold according to the second pilot sequence, and recover the digital information from the first pilot sequence by using the decision threshold.

Further, referring to FIG. 10, which is a schematic flowchart of S205 in FIG. 9, S205 specifically includes: S2051: performing fast Fourier transform FFT processing on the first pilot sequence to obtain a first frequency domain sequence.

S2052: Perform FFT processing on the second pilot sequence to obtain a second frequency domain sequence.

52053. Calculate a first signal power corresponding to a frequency in the first frequency domain sequence.

52054. Calculate a second signal power and a signal to noise ratio corresponding to the frequency f ₂ in the second frequency domain sequence.

52055. Calculate a decision threshold according to the second signal power and the signal to noise ratio.

52056. Retrieve the digital information after determining the first signal power according to the decision threshold. - - Optionally, the decision threshold is calculated according to the formula P _fh = k ² * (P ₇ - M * ^), where k is

N ₂

The ratio of the maximum amplitude of the carrier signal to the maximum amplitude of the second pilot signal is a decision threshold, which is the second signal power, ^N 2 is the noise power of the second pilot signal, and M is a constant , 0<M<1;

If the first signal power > Ρ _ώ , the bit bit of the symbol duration is judged to be 1, if

The judgment is 0.

The embodiment and the second embodiment of the device are in the same concept, and the technical effects are also the same. For the specific process, refer to the description of the second embodiment of the device, and details are not described herein again.

A person skilled in the art can understand that all or part of the steps of implementing the above method embodiments may be completed by using hardware related to the program instructions. The foregoing program may be stored in a computer readable storage medium, and the program is executed when executed. The foregoing steps include the steps of the foregoing method embodiments; and the foregoing storage medium includes: a medium that can store program codes, such as a ROM, a RAM, a magnetic disk, or an optical disk.

The method, device and system provided by the embodiments of the present invention are described in detail above, and are used herein to help understand the method and core idea of the present invention. Meanwhile, for those skilled in the art, according to the idea of the present invention, The details of the present invention and the scope of the application are subject to change. The contents of the present specification are not to be construed as limiting the invention.

Claims

Rights request

1. A communication device, characterized by including:

The first pilot generation module is used to load digital information onto the carrier signal to generate the first pilot signal. The frequency of the carrier signal is

The second pilot generation module is used to generate a second pilot signal that is not loaded with digital information, and the frequency of the second pilot signal is f ₂ , f ₂ ≠ f _x ;

An adder, used to add the first pilot signal and the second pilot signal to generate a total pilot signal;

A modulator, used to modulate the total pilot signal into a signal to be loaded with a pilot, to obtain a signal loaded with a pilot.

2. The communication device according to claim 1, further comprising:

A frequency allocation module, configured to select the f 2 and f ₂ from a preset pilot frequency allocation table and assign them to the carrier signal and the second pilot signal respectively.

3. The communication device according to claim 1 or 2, wherein the maximum amplitude of the carrier signal is equal to or proportional to the maximum amplitude of the second pilot signal.

4. A communication device, characterized by including:

The first filtering module is used to filter the pilot-loaded signal to obtain a first pilot signal. The first pilot signal is generated by loading digital information onto a carrier signal. The frequency of the carrier signal is f.

The second filtering module is used to filter the pilot-loaded signal to obtain a second pilot signal. The second pilot signal does not carry digital information, and the frequency of the second pilot signal is f. ₂ , i ₂ 1 ₁ ,

A first analog-to-digital conversion module, used to perform analog-to-digital conversion on the first pilot signal to obtain a first pilot sequence;

A second analog-to-digital conversion module is used to perform analog-to-digital conversion on the second pilot signal to obtain a second pilot sequence. Bad ¹ J ;

A digital information recovery module, configured to calculate a decision threshold based on the second pilot sequence, and use the decision threshold to recover the digital information from the first pilot sequence.

5. The communication device according to claim 4, wherein the pilot-loaded signal is an electrical signal loaded with a pilot, and the communication device further includes:

A photoelectric conversion module, configured to convert the pilot-loaded optical signal into the pilot-loaded electrical signal before filtering by the first filtering module and the second filtering module.

6. The communication device according to claim 5, further comprising:

An amplification module, configured to amplify the pilot-loaded electrical signal by 10,000 DC and amplitude, and then input it to the first filter module and the second filter module.

7. The communication device according to any one of claims 4 to 6, characterized in that the maximum amplitude of the carrier signal is equal to or proportional to the maximum amplitude of the second pilot signal.

8. The communication device according to claim 7, wherein the sampling frequency of the second analog-to-digital conversion module is less than 2 f ₂ .

9. The communication device according to any one of claims 4 to 8, characterized in that the digital information is a binary sequence, and the digital information recovery module includes:

The first FFT unit is used to perform Fast Fourier Transform FFT processing on the first pilot sequence to obtain the first frequency domain sequence;

The second FFT unit is used to perform FFT processing on the second pilot sequence to obtain a second frequency domain sequence;

A first power calculation unit, used to calculate the first signal power corresponding to frequency in the first frequency domain sequence;

A second power calculation unit, used to calculate the second signal power and signal-to-noise ratio corresponding to frequency 4 in the second frequency domain sequence;

a threshold calculation unit, configured to calculate a decision gate based on the second signal power and the signal-to-noise ratio limited;

A digital information recovery unit, configured to determine the first signal power according to the decision threshold and then recover the digital information.

10. The communication device according to claim 9, characterized in that,

The threshold calculation unit is used to calculate the decision gate according to the formula P _fh = k ² * (P _? - M)

N ₂

limit, where k is the ratio of the maximum amplitude of the carrier signal to the maximum amplitude of the second pilot signal, is the decision threshold, is the power of the second signal, ^N 2 is the power of the second pilot signal Noise power, M is a constant, 0 < M <1;

The digital information recovery unit is configured to determine the bit corresponding to the first signal power to be 1 if the first signal power > P _th , and to determine the bit to be 0 if P th .

11. A signal modulation method, characterized by including:

Load digital information onto a carrier signal to generate a first pilot signal. The frequency of the carrier signal is to generate a second pilot signal without digital information. The frequency of the second pilot signal is f ₂ . f ₂ will be The first pilot signal and the second pilot signal are added to generate a total pilot signal;

The total pilot signal is modulated into a signal to be loaded with a pilot, to obtain a signal loaded with a pilot.

12. The modulation method according to claim 11, characterized in that, before the step of loading digital information onto the carrier signal to generate the first pilot signal, it further includes:

The and are selected from a preset pilot frequency allocation table and allocated to the carrier signal and the second pilot signal respectively.

13. The modulation method according to claim 11 or 12, characterized in that the maximum amplitude of the carrier signal is equal to or proportional to the maximum amplitude of the second pilot signal.

14. A method for recovering digital information, characterized by including:

Filter the pilot-loaded signal to obtain a first pilot signal. The first pilot signal Generated by loading digital information onto a carrier signal whose frequency is

The pilot-loaded signal is filtered to obtain a second pilot signal. The second pilot signal does not carry digital information. The frequency of the second pilot signal is f ₂ , f ₂ ≠ f _{1 ;}

Perform analog-to-digital conversion on the first pilot signal to obtain a first pilot sequence;

Perform analog-to-digital conversion on the second pilot signal to obtain a second pilot sequence;

Calculate a decision threshold based on the second pilot sequence, and use the decision threshold to recover the digital information from the first pilot sequence.

15. The recovery method according to claim 14, wherein the pilot-loaded signal is a pilot-loaded electrical signal, and the pilot-loaded signal is filtered to obtain the first pilot. Before the signal step, it also includes:

The pilot-loaded optical signal is converted into the pilot-loaded electrical signal.

16. The recovery method according to claim 14 or 15, wherein the maximum amplitude of the carrier signal is equal to or proportional to the maximum amplitude of the second pilot signal.

17. The recovery method according to any one of claims 14 to 16, wherein the step of performing analog-to-digital conversion on the second pilot signal to obtain a second pilot sequence includes:

The second pilot signal is subjected to undersampling processing to obtain a second pilot sequence, the sampling frequency of which is less than 2 f ₂ .

18. The recovery method according to claim 17, wherein the digital information is a binary sequence, the decision threshold is calculated according to the second pilot sequence, and the decision threshold is used to obtain the result from the first The steps of recovering the digital information in the pilot sequence include:

Perform Fast Fourier Transform (FFT) processing on the first pilot sequence to obtain a first frequency domain sequence; Perform FFT processing on the second pilot sequence to obtain a second frequency domain sequence;

Calculate the first signal power corresponding to frequency in the first frequency domain sequence;

Calculate the second signal power and signal-to-noise ratio corresponding to frequency f ₂ in the second frequency domain sequence; calculate a decision threshold based on the second signal power and the signal-to-noise ratio;

The first signal power is determined according to the determination threshold and the digital information is restored.

19. The recovery method according to claim 18, wherein: a decision threshold is calculated based on the second signal power and the signal-to-noise ratio; and the first signal power is determined based on the decision threshold. The steps to recover the digital information include:

Calculate the decision threshold according to the formula P _fh = k ² * (P ₇ - M *), where k is the carrier

² N ₂

The ratio of the maximum amplitude of the signal to the maximum amplitude of the second pilot signal is the decision threshold, is the power of the second signal, ^N 2 is the noise power of the second pilot signal, M is a constant, 0 < Μ <1;

If the first signal power > p _th , then the bit corresponding to the first signal power is judged to be 1, and if so, the bit corresponding to the first signal power is judged to be 0.

20. A communication device, characterized in that it includes a processor and a memory. A set of program codes is stored in the memory. The processor calls the program code stored in the memory to perform the following operations:

Loading digital information onto a carrier signal to generate a first pilot signal, the frequency of the carrier signal is 1,

Generate a second pilot signal that is not loaded with digital information, and the frequency of the second pilot signal is f ₂ , f ₂ × 1,

Add the first pilot signal and the second pilot signal to generate a total pilot signal;

The total pilot signal is modulated into the signal to be loaded with pilot frequency, and a signal loaded with pilot frequency is obtained.

21. The communication device according to claim 20, characterized in that the processor is also used to execute:

22. The communication device according to claim 20 or 21, wherein the maximum amplitude of the carrier signal is equal to or proportional to the maximum amplitude of the second pilot signal.

23. A communication device, characterized in that it includes a processor and a memory, a set of program codes stored in the memory, and the processor calls the program codes stored in the memory to perform the following operations:

The pilot-loaded signal is filtered to obtain a first pilot signal. The first pilot signal is generated by loading digital information onto a carrier signal. The frequency of the carrier signal is;

24. The communication device according to claim 23, wherein the pilot-loaded signal is a pilot-loaded electrical signal, and the processor is further configured to execute:

25. The communication device according to claim 23 or 24, characterized in that,

The maximum amplitude of the carrier signal is equal to or proportional to the maximum amplitude of the second pilot signal.

26. The communication device according to any one of claims 23 to 25, wherein the processor performing the step of performing analog-to-digital conversion on the second pilot signal to obtain the second pilot sequence includes:

The second pilot signal is subjected to undersampling processing to obtain the second pilot sequence, the sampling frequency of which is less than 2 f ₂ .

27. The communication device according to claim 34, wherein the digital information is a binary sequence, the processor executes the calculation of the decision threshold based on the second pilot sequence, and uses the decision threshold The step of recovering the digital information from the first pilot sequence includes:

Perform fast Fourier transform FFT processing on the first pilot sequence to obtain a first frequency domain sequence; Perform FFT processing on the second pilot sequence to obtain a second frequency domain sequence;

The digital information is recovered after determining the first signal power according to the determination threshold.

28. The recovery device according to claim 27, wherein the processor is further configured to calculate a decision threshold based on the second signal power and the signal-to-noise ratio; The step of recovering the digital information after determining the first signal power includes:

Calculate the decision threshold according to the formula P _fh =k ² *(P ₇ - M*), where k is the carrier

² N ₂

The ratio of the maximum amplitude of the signal to the maximum amplitude of the second pilot signal is the decision threshold, is the power of the second signal, ^N 2 is the noise power of the second pilot signal, M is a constant, 0<Μ<1;

If the first signal power > p _th , the bit corresponding to the first signal power is judged to be 1, and if Pth, the bit corresponding to the first signal power is judged to be 0.

29. A communication system, characterized by comprising the communication device according to any one of claims 1 to 3 and 4 to 10 and the communication device according to any one of claims 20 to 22 and 23 to 28.