WO2016008159A1

WO2016008159A1 - Communication device and system, and method for processing signal

Info

Publication number: WO2016008159A1
Application number: PCT/CN2014/082525
Authority: WO
Inventors: 陈微; 满江伟; 曾理
Original assignee: 华为技术有限公司
Priority date: 2014-07-18
Filing date: 2014-07-18
Publication date: 2016-01-21
Also published as: CN106664109A; CN106664109B

Abstract

Provided are a communication device and system, and a method for processing a signal. A fixed reflection delay in a communication link and a corresponding reflection coefficient are used to eliminate reflection crosstalk caused by a reflection signal, and improve communication quality.

Description

Communication device, system and method for processing signal

The present invention relates to the field of communications technologies, and in particular, to a communication device, a system, and a method for processing a signal. Background technique

As communication rates continue to increase, optical communications are becoming more popular.

In optical communication, a signal is transmitted over a wavelength of light. The optical signal is reflected in the transmission medium or at the intermediate node of the transmission during transmission. The reflected signal produced by this reflection phenomenon is a kind of crosstalk for the normal signal, which will affect the system performance.

In fact, optical signals may experience multiple reflections in the transmission medium or at the intermediate nodes of the transmission. The reflected signal generated by the multiple reflections eventually enters the optical receiver together with the normal optical signal, thereby seriously affecting system performance. When the transmission intermediate node is damaged, or the number of intermediate nodes is large, the optical signal may be sharply deteriorated due to the crosstalk of the reflected signal. At the same time, the communication rate is continuously increased, and the modulation order of the optical signal is also getting higher and higher. As the modulation order of the optical signal increases, the influence of the reflected signal becomes more apparent.

Therefore, how to eliminate the crosstalk of the reflected signal has become an urgent problem to be solved. Summary of the invention

In view of this, embodiments of the present invention provide a communication apparatus, a system, and a method of processing a signal. In a first aspect, an embodiment of the present invention provides a communication apparatus, where the communication apparatus includes: a receiving port, configured to receive a signal from a communication link; and a processing component, configured to perform a reflection delay in the communication link according to the signal And a reflection coefficient corresponding to the reflection delay canceling crosstalk in the signal from the communication link, the reflection delay being a delay between the reflected signal and the unreflected signal, The reflection coefficient is the ratio between the amplitude of the reflected signal and the amplitude of the unreflected signal.

In a second aspect, an embodiment of the present invention provides a communication system including the communication device provided by the first aspect.

In a third aspect, an embodiment of the present invention provides a method for processing a signal, which may be applied to the first Aspect, the communication device or communication system provided by the second aspect. The method includes: receiving a signal from a communication link; eliminating crosstalk in the signal from the communication link based on a reflection delay of the signal in the communication link and a reflection coefficient corresponding to the reflection delay, The reflection delay is a delay between a reflected signal and a non-reflected signal, the reflection coefficient being a ratio between an amplitude of the reflected signal and an amplitude of the unreflected signal.

In a static communication link, the parameters related to the reflected signals from the transmitting end to the receiving end are also fixed as long as the attributes of the corresponding physical components are not changed. For example, the electro-optical conversion efficiency of the transmitter at the transmitting end, the attenuation of the optical fiber in the transmission path, the reflectivity of the transmission intermediate node, and the photoelectric conversion efficiency of the receiver are all fixed. In the embodiment of the present invention, according to the fixed reflection delay of the signal in the communication link and the corresponding reflection coefficient, the reflected crosstalk caused by the reflected signal is eliminated, and the quality of the communication is improved. DRAWINGS

The drawings used in the embodiments or the description of the prior art are briefly described. It is obvious that the drawings in the following description are some embodiments of the present invention, and are not creative to those skilled in the art. Other drawings can also be obtained from these drawings on the premise of labor.

FIG. 1 is a schematic structural diagram of a system according to an embodiment of the present disclosure;

2 is a structural diagram of a communication device according to an embodiment of the present invention;

3 is a schematic diagram of a reflection coefficient analysis result according to an embodiment of the present invention;

4 is a structural diagram of a processing component according to an embodiment of the present invention;

FIG. 5 is a structural diagram of a beat frequency item processing unit in a processing component according to an embodiment of the present invention. detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is a partial embodiment of the invention, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention. The communication device, the communication system and the method for processing the signal are provided by the embodiments of the present invention. The technical means mentioned in the embodiments are interoperable, can be combined with each other, and can learn from each other.

Figure 1 shows a communication system including a communication device, a digital to analog converter, a transmitter, a circulator, an optical transmission path, and a transmission intermediate node. In Figure 1, the optical transmission path is mainly between the two circulators, of course, from the transmitter to the circulator, and from the circulator to the receiver is also part of the optical transmission path. In Figure 1, the transmission intermediate nodes are schematically represented by short vertical bars. The intermediate node of the transmission may be a connecting device or an optical amplifying device or the like, which is not limited in the embodiment of the present invention. For convenience of explanation, in the embodiment of the present invention, the left part of the optical transmission path between the two circulators is referred to as a local, and the right part of the optical transmission path is referred to as a opposite end. The communication subsystems of the opposite end are not all drawn. For the specific structure, refer to the structure on the left side of Fig. 1. Wherein, the communication device is configured to receive, process, and transmit an electrical signal; the digital to analog converter is configured to convert the digital electrical signal from the communication device into an analog electrical signal; and the transmitter is configured to modulate the analog electrical signal from the digital to analog converter to the optical Forming an optical signal and transmitting the optical signal to the circulator; the circulator is configured to send the optical signal from the local transmitter to the opposite end, and send the optical signal from the opposite end to the local receiver.

The communication system in FIG. 1 may be a single-fiber bidirectional intensity modulation-direct detection (IM-DD) communication system, or may be a similar other communication system, which is not limited in the embodiment of the present invention. IM-DD refers to the intensity of the modulated optical carrier at the transmitting end. The receiver performs envelope detection on the optical carrier to determine the signal to be carried. The signal can be transmitted by the presence or absence of light or the intensity of light. In the communication system, the uplink signal and the downlink signal may be carried in the same wavelength, and may be carried in different wavelengths, which is not limited in the embodiment of the present invention.

It can be seen from FIG. 1 that in the optical transmission path, due to light scattering, reflection, etc., an optical signal partially opposite to the normal optical signal transmission direction is generated. This part of the signal is referred to as a reflected signal in the embodiment of the present invention, or Reflect crosstalk signals, or reflected crosstalk, or crosstalk signals, or crosstalk.

Such a reflected crosstalk signal may be caused by an even number of reflections or scattering of the optical signal transmitted by the opposite end in the optical transmission path, which is denoted as _ri (t) in the embodiment of the present invention. _Ri (t) in Figure 1 is only illustrative, in fact _ri (t) may include one or more reflection crosstalk.

Each reflected crosstalk has its own transmission path and the delay corresponding to its transmission path. The delay here, also called the reflection delay, refers to the time delay between the reflected signal and the unreflected signal. Because the reflected signal is transmitted a distance more than the unreflected signal, there is a certain delay between the reflected signal and the unreflected signal. The value of this delay should This is equal to the distance of the multi-transmission divided by the quotient of the speed of the light in the corresponding transmission medium. For example, if a crosstalk signal transmits a distance of L in the optical transmission path due to reflection, and the speed of the optical signal in the optical transmission path is c, the reflection delay corresponding to the crosstalk signal should be equal to L/C.

At the same time, each reflection crosstalk has its own reflection coefficient. The reflection coefficient of the embodiment of the present invention refers to the ratio between the amplitude of the reflected signal and the amplitude of the unreflected signal. The amplitude of the signal here refers to the amplitude of the electrical signal after the photoelectric conversion of the optical signal. Of course, it is well known in the art that during electro-optical conversion, the amplitude of the electrical signal is proportional to the intensity of the optical signal. Therefore, for 0, the reflection coefficient of the embodiment of the present invention may also be the ratio between the intensity of the reflected optical signal and the intensity of the unreflected optical signal. This reflection coefficient is closely related to the reflectance of each reflection of the reflected crosstalk. When the reflectance of each reflection is small, the reflection coefficient can be approximated as the product of the reflectances of all the reflections.

In addition, the reflected crosstalk may also be caused by an odd number of reflections or scattering of the locally transmitted optical signal in the optical transmission path, which is referred to as r ₂ (t) in the embodiment of the present invention. Similarly, r ₂ (t) may also include multiple reflection crosstalks, each of which corresponds to a corresponding reflection delay, and each reflection crosstalk also corresponds to a corresponding reflection coefficient. The reflection coefficient here also refers to the ratio between the amplitude of the reflected signal and the amplitude of the unreflected signal. It is worth noting that for r ₂ (t), the unreflected signal can be directly represented by the locally transmitted electrical signal. Therefore, when determining the reflection coefficient of the reflected crosstalk signal in r ₂ (t), the electrical signal d ₂ ( t ) is first converted into the optical signal 3⁄4 ( t ), and then s ₂ ( t ) is detected in the optical transmission path. Reflecting the crosstalk signal, converting the reflected crosstalk signal into an electrical signal d ₂ ( t+T ₂ ), where T ₂ represents a corresponding reflection delay, then the reflection coefficient of the reflected crosstalk signal is d ₂ ( t+T ₂ ) The ratio of the magnitude to the magnitude of d ₂ ( t ).

The specific principles of the embodiments of the present invention will be explained below. As shown in FIG. 1 , the reflected crosstalk mainly includes two parts, and a part of the signal sent by the opposite end is formed by multiple reflections in the communication link, and the part of the reflected crosstalk signal is recorded as _ri (t), and the other part is locally transmitted. The signal is formed by one or more reflections in the communication link, and this partially reflected crosstalk signal is denoted as r ₂ (t). At the same time, the unreflected signal transmitted by the opposite end is recorded as s(t), and s(t) is the normal signal required by the local. The purpose of eliminating the crosstalk is mainly to eliminate the s(t) except Other signals.

Record the total reflected crosstalk as r(t), where r(t) = _ri (t) + r ₂ (t), then the electrical signal that is ultimately produced in the receiver can be expressed as: l(t) = A\s(t) + r(tf =

= I, + I ₂ + I _{3 in the} above formula, l _{l =}

, is the required signal term; Ι ₂ = 2Α · + Α φ)) ² , is the beat frequency term of the signal and reflection, the frequency difference between the signal and the reflection, ^Δ ^ is the phase difference between the signal and the reflection; / ₃ = 4^ ) | ² , is the reflection term. Where Α is the electro-optic conversion coefficient of the optical signal s(t)+r(t) converted into the optical signal I(t), which is a constant for a given receiver. For signal I, both 1 ₂ and 1 ₃ are crosstalk terms. It is worth noting that when the main reflected crosstalk in the communication system is "^", and r ₂ (t) is relatively weak, only the crosstalk caused by (t) can be eliminated, and r ₂ (t) is ignored. Crosstalk, that is, let r(t) = (t); Similarly, when the main reflected crosstalk in the communication system is r ₂ (t), and "^" is relatively weak, it can only eliminate r ₂ (t) The crosstalk caused, and the crosstalk of (t) is ignored, that is, let r(t) = r ₂ (t); of course, the crosstalk of "^) and r ₂ (t) can be eliminated at the same time. In addition, only the reflection term can be eliminated. Crosstalk ignores the crosstalk of the beat frequency term, or only eliminates the beat frequency term and ignores the crosstalk of the reflection term. In the above several ways, the crosstalk of the reflection can be eliminated to some extent, and the communication quality is improved. As shown in FIG. 2, the embodiment of the present invention Providing a communication device, the communication device comprising: a receiving port for receiving a signal from a communication link; and processing means for reflecting a reflection delay and the reflection delay in the communication link according to the signal Corresponding reflection coefficients cancel crosstalk in the signal from the communication link, the reflection After the delay between when the reflected signal and the signal has not been reflected through the reflection coefficient of the amplitude of the signal reflected by the ratio between the amplitude of the reflected signal has not elapsed.

The processing component is specifically configured to: use the reflection delay as a filtering delay of the filtering process, and use a negative value of the reflection coefficient corresponding to the reflection delay as a filter coefficient of the filtering process, according to the filtering delay And a filter coefficient filtering the signal from the communication link to eliminate crosstalk in the signal from the communication link.

Because each reflected crosstalk has a fixed reflection delay and reflection coefficient, these reflection delays and reflection coefficients are measurable. The processing component can eliminate the corresponding reflected crosstalk based on known reflection delays and reflection coefficients.

For example, for the crosstalk of the reflection term caused by the signal sent by the peer, the processing component can be configured. In order to filter according to the reflection delay Ί\ and the reflection coefficient to eliminate (^(t+T † crosstalk signal Rj · d!(t), where (!^+^ is t+T engraved received from The unfiltered signal of the communication link is a signal received from the communication link and filtered by the wave at time t, and the reflection delay Ί\ is sent by the opposite end of the communication link. The delay between the reflected signal and the unreflected signal transmitted by the opposite end of the communication link, the reflection coefficient being the amplitude and the amplitude of the reflected signal transmitted by the opposite end of the communication link The ratio between the amplitudes of the unreflected signals transmitted by the opposite end of the communication link.

4 (0 is a filtered electrical signal, which can be approximated as an accurate signal. Alternatively, (0 can also be judged by the decision-processed signal, the signal processed by the decision is closer to the real signal.

The reflected crosstalk caused by the optical signal corresponding to (0) will be delayed by 4 (0 arrives at the processing unit, and the delayed time is the corresponding reflection delay Ί\. That is, the processing component is after 0\ The received signal c^t+TO is mixed with 4 (0) reflected crosstalk signal. This reflected crosstalk signal is filtered 4 (multiplied by the corresponding reflection coefficient. The specific method of eliminating crosstalk is Subtracting ·4 (0) from the c^t+T signal. The so-called subtraction of d!(t) can be achieved by configuring the filter coefficients in the processing unit. For example, the filter coefficient can be configured as a negative value of the reflection coefficient. You can do the following filtering processing at t+ T, let (1^+^)= d +T - · d!(t), or let d ₁ (t+T ₁ )= d^t+T · ( ΐ - Ri - d ty c^t+T ).

For the reflection term crosstalk caused by the locally transmitted signal, the processing component may be configured to perform filtering processing according to the reflection delay Τ ₂ and the reflection coefficient R ₂ to eliminate the crosstalk signal R ₂ in (1^+ T ₂ ). d ₂ (t), where (^(t+Ts) is the unfiltered signal received from the communication link received at time t+T ₂ , (1 ₂ (3⁄4 is locally sent to the communication link) a signal, the reflection delay being a delay between a locally transmitted reflected signal and a locally unreflected signal, the reflection coefficient R ₂ being the amplitude of the reflected signal transmitted locally and the local not The ratio between the amplitudes of the reflected signals. It is worth noting that d ₂ (t) is sent locally, so it can be copied directly locally, which should be theoretically accurate. The reflection delay T ₂ is the time difference between the locally obtained d ₂ (t) and the locally obtained d ₂ (t) reflected signal. The method of eliminating the crosstalk caused by the locally transmitted signal and the method of eliminating the transmission of the opposite end Reflection term crosstalk caused by signal A similar law, not repeat them here.

In the crosstalk of the reflection term caused by the signal transmitted locally, and the crosstalk of the reflection term caused by the signal transmitted by the opposite end, only one of them can be eliminated (if the other item is weak and negligible), Both can be eliminated at the same time, which can eliminate reflection crosstalk to a certain extent and improve communication quality. The method of eliminating both at the same time is similar, and it is possible to subtract the corresponding total reflected crosstalk signal from the unfiltered signal.

The above description refers to the method of eliminating a reflected crosstalk. In fact, there are multiple reflection crosstalks in the communication link, and each reflection crosstalk has its own reflection delay and reflection coefficient. Of course, the principle is the same, the only difference is that the crosstalk that needs to be subtracted during the filtering process is the sum of all the crosstalk. For example, when there are n reflection crosstalks, the reflection delays corresponding to the n reflection crosstalks are (Ί\ , Τ ₂ , ... Τ _η ), and the corresponding reflection coefficients are ( , R ₂ , ... R _n ), Then the corresponding filtering process should be d!(t)- R! · d _x (t- T - R ₂ · (t- T ₂ )... - R _n · d _x (t- T _n ). x is equal to 1 or 2. When x is equal to 1, it indicates that the signal is the filtered signal sent by the opposite end. When X is equal to 2, it indicates that the signal is a locally copied signal.

The method is to eliminate the above-described ₁₃ caused crosstalk reflection items. Further, optionally, the crosstalk caused by the beat frequency item can be eliminated, and the communication quality is further improved. For crosstalk of the beat frequency term, the processing component is configured to: obtain a reflected signal according to a reflection delay and a reflection coefficient corresponding to the reflection delay; perform a decision process on the filtered signal; The signal processed by the decision is multiplied, and the multiplied result is conjugated; the filter-processed signal and the conjugated signal are autocorrelation detected; and the autocorrelation detection result is subjected to fast Fourier transform FFT, Obtaining a frequency domain signal after the FFT; calculating a beat frequency crosstalk caused by the reflected signal according to a position of a peak point of the frequency domain signal and an intensity of a peak point, and eliminating a beat frequency in the filtered signal Item crosstalk.

According to the above description, the elimination of crosstalk requires obtaining two parameters of reflection delay and reflection coefficient. The two parameters may be locally configured, and may be determined when the system is initialized, and may be provided by the network management system, or may be periodically determined. The method for obtaining the two parameters is not limited in the embodiment of the present invention.

The following is an example of how to determine the reflection delay and reflection coefficient.

For the locally transmitted signal, the communication device further includes a sending port, the sending port is configured to send a first training sequence signal, and the receiving port is further configured to receive the first training sequence signal in the communications chain The signal reflected in the road; the processing component is further configured to: perform auto-correlation detection on the reflected signal of the first training sequence signal and the first training sequence signal to obtain a reflection delay and a reflection coefficient. The first training sequence signal may be interspersed in the service signal, or may be sent separately, or may be transmitted in a low-depth low-frequency dome in the service signal. Preferably, in the process of determining the reflection delay and the reflection coefficient, the transmitter of the opposite end does not transmit a signal. The processing component receives the reflected first training sequence signal, and performs autocorrelation detection on the locally copied first training sequence signal and the reflected signal of the first training sequence signal. Autocorrelation refers to the dependence of the instantaneous value of a signal at one moment with the instantaneous value of another moment, and is a time domain description of a random signal. For the transmitted training sequence, it can be regarded as a set of random numbers, each sequence is only related to itself, and there is no correlation between the sequences.

The specific method for obtaining the reflection delay and the reflection coefficient is as follows: performing an autocorrelation curve on the first training sequence signal and the reflected signal of the first training sequence signal, and performing an autocorrelation curve on the first training sequence signal and itself The autocorrelation gets an autocorrelation value. The autocorrelation curve is then divided by the resulting autocorrelation value. Specifically, the autocorrelation curve divided by the autocorrelation value can be expressed as:

c. Rre!ati. «Tr,, r( + Τ ) correlatio n, d(,, R ά(τ + Τ)) _ Rcotrektti. η(ά(τ ά(τ + Τ ) correlationid (τ), d (τ)) correlatio n{d (τ), d (τ)) correlation{d (τ), d (τ)) because of the reflected signal The same as when the signal is sent, but the time is different, so there is ά(τ + Τ) = ά(τ) ₀ so the above formula can be expressed as:

,d

It can be seen that the result of dividing the autocorrelation curve by the obtained autocorrelation value is the reflection coefficient R. The result of dividing the two is shown in Figure 3. In Fig. 3, Ί\, Τ ₂ , Τ ₃ and Τ _{4 are} the corresponding reflection delays, and the vertical axis corresponding to Ί\, τ ₂ , τ ₃ and τ ₄ is the reflection coefficient. After obtaining the corresponding reflection delay and reflection coefficient, the processing component can eliminate the reflected crosstalk in the manner described above.

For the reflection crosstalk caused by the signal transmitted by the opposite end, the reflection delay and the reflection coefficient are measured in a similar manner, that is, the processing component, and is also used to utilize the locally known second training sequence signal and the second transmission sent by the opposite end. The training sequence performs autocorrelation detection to obtain reflection delay and reflection coefficient. In one case, the second training sequence transmitted by the peer end is known locally or is a double-ended convention. In this case, the auto-correlation detection can be performed directly using the known training sequence. If the second training sequence number transmitted by the peer end is unknown to the local, the filtered and processed signal can be used as the known second training sequence, and the auto-correlation detection is performed with the training sequence that is taken over.

The processing component described above may include a processor and a memory, and corresponding instructions are stored in the memory Or a program for executing a program or program in a memory to implement a series of functions of the processing components described in the embodiments of the present invention. In addition, the function of the processing component can also be solidified in the corresponding hardware. For example, the processing component can be a Field Programmable Gate Array (FPGA), or can be embodied as a corresponding logic array, and can be a digital The signal processor (DSP) can also be an application specific integrated circuit (ASIC), etc., and the above is only an example, and what kind of device is used to implement the functions of the embodiments of the present invention. No restrictions.

The internal structure of the processing component can be as shown in Fig. 4. Of course, Fig. 4 is merely an example and is not intended to limit the internal structure of the processing component.

As shown in Fig. 4, the processing unit may internally include a transmission signal processing unit, a reflection item processing unit, a filtering unit, and a beat frequency item processing unit.

The sending signal processing unit is configured to generate and encode the signal, and send the encoded data, and may also be used to receive the service signal, process and send the service signal, and may also be used to process the predetermined training sequence. The signals are interleaved into corresponding service signals and sent out. When measuring the reflection delay and the reflection coefficient, the transmission signal processing unit may be configured to send the transmitted training sequence signal to the reflection item processing unit for autocorrelation detection. When it is required to eliminate the reflected crosstalk caused by the locally transmitted signal, the transmission signal processing unit may be configured to send a copy of the transmitted service signal to the unit for filtering, and simultaneously copy a signal to the reflection item processing unit. It is used to generate a reflected signal when it is necessary to eliminate the crosstalk of the beat frequency term.

The reflection term processing unit is configured to receive a signal from the transmitting signal processing unit and/or from the receiving port for determining the reflection delay and the reflection coefficient, and performing autocorrelation detection. The reflection term processing unit is further configured to configure the filtering unit based on the reflection delay and the reflection coefficient. When it is desired to eliminate the beat frequency term crosstalk, the obtained reflection coefficient, and corresponding signals from the transmission signal processing unit and from the filtering unit are used to generate a reflected signal.

The filtering unit is configured to filter the received signal according to a reflection delay and a reflection coefficient configured by the reflection item processing unit. In FIG. 4, the signals fed back by the decision unit and the transmission signal processing unit are schematically filtered, and in fact the filtering process of the two may be separate. For the reflected crosstalk caused by the locally transmitted signal, the signal transmitted by the transmission signal processing unit and the reflection delay and reflection coefficient of the reflected signal corresponding to the signals are used for filtering processing. For the reflected crosstalk caused by the signal transmitted by the opposite end, the signal fed back by the decision unit is used, and The corresponding reflection delay and reflection coefficient are filtered. The filtering unit also provides a filtered signal and a decision processed signal to the beat frequency item processing unit. At the same time, the decision unit in the filtering unit also feeds back a signal to the reflection item processing unit for subsequent generation of the reflected signal.

The specific structure of the beat frequency item processing unit is as shown in FIG. 5. The mathematical operation unit multiplies the reflected signal by the signal subjected to the decision processing, and conjugates the result of the multiplication. The reflected signal is provided by the reflection item processing unit, and the reflection item processing unit multiplies the decision processed signal provided by the decision unit by the corresponding reflection coefficient to obtain a reflected signal _ri (t) caused by the signal transmitted by the opposite end, The signal provided by the transmitting signal processing unit is multiplied by the corresponding reflection coefficient to obtain the reflected signal r ₂ (t) caused by the locally transmitted signal, and the sum is added as the total reflected signal. The autocorrelation unit is configured to perform autocorrelation detection on the filtered signal and the conjugated signal. The Fourier transform unit is configured to perform a fast Fourier transform FFT on the result of the autocorrelation detection to obtain a frequency domain signal after the FFT. The parameter processing unit is configured to calculate a beat frequency term crosstalk caused by the reflected signal according to a position of a peak point of the frequency domain signal and an intensity of a peak point, and cancel a beat frequency term crosstalk in the filtered signal.

An embodiment of the present invention further provides a method for signal processing, the method comprising: receiving a signal from a communication link; and reflecting a reflection delay in the communication link according to the signal and corresponding to the reflection delay A reflection coefficient cancels crosstalk in the signal from the communication link, the reflection delay being a delay between the reflected signal and the unreflected signal, the reflection coefficient being the amplitude of the reflected signal The ratio between the amplitude of the unreflected signal.

Specifically, the canceling the crosstalk in the signal from the communication link according to a reflection delay of the signal in the communication link and a reflection coefficient corresponding to the reflection delay, including: extending the reflection As a filtering delay of the filtering process, a negative value of the reflection coefficient corresponding to the reflection delay is used as a filter coefficient of the filtering process, and the signal from the communication link is performed according to the filtering delay and the filter coefficient. Filtering is performed to eliminate crosstalk in the signal from the communication link.

Specifically, the removing the crosstalk in the signal from the communication link according to a reflection delay of the signal in the communication link and a reflection coefficient corresponding to the reflection delay, including:

Filtering is performed according to the reflection delay Ί\ and the reflection coefficient to eliminate the crosstalk signal d!(t) in d^t+T, where (!^+^ is the time from the communication link received at t+ time Filtered signal, 4 (0 is the signal received from the communication link and filtered by the wave at time t, the reflection delay Ί\ is the reflected by the opposite end of the communication link Delay between the signal and the unreflected signal transmitted by the opposite end of the communication link, the reflection coefficient a ratio between the amplitude of the reflected signal transmitted by the opposite end of the communication link and the amplitude of the unreflected signal transmitted by the opposite end of the communication link; and/or

Filtering is performed according to the reflection delay T ₂ and the reflection coefficient R ₂ to eliminate the crosstalk signal R ₂ . d ₂ (t) in (1^+ T ₂ ), where d^t+T is received at t+T ₂ And the unfiltered signal from the communication link, d ₂ (t) is a signal sent locally to the communication link, and the reflection delay T ₂ is a reflected signal transmitted locally and A delay between signals that are not locally reflected, the reflection coefficient R ₂ being the ratio between the amplitude of the locally transmitted reflected signal and the amplitude of the locally unreflected signal.

Further, the step of canceling the crosstalk in the signal from the communication link according to a reflection delay of the signal in the communication link and a reflection coefficient corresponding to the reflection delay further includes: according to a reflection delay Obtaining a reflected signal with a reflection coefficient corresponding to the reflection delay; performing a decision process on the filtered signal; multiplying the reflected signal by the signal subjected to the decision processing, and conjugate the result of the multiplication; Performing autocorrelation detection on the filtered signal and the conjugated signal; performing fast Fourier transform FFT on the result of the autocorrelation detection to obtain an FFT frequency domain signal; according to the peak point of the frequency domain signal The position and the intensity of the peak point calculate the beat frequency term crosstalk caused by the reflected signal, and cancel the beat frequency term crosstalk in the filtered signal.

Optionally, the method further includes: transmitting a first training sequence signal; receiving a signal that is reflected by the first training sequence signal in the communication link; and using the first training sequence signal and the first training The reflected signal of the sequence signal is subjected to autocorrelation detection to obtain a reflection delay and a reflection coefficient; and/or, the second training sequence signal sent by the opposite end is received; and the second known training sequence signal is locally transmitted with the peer The second training sequence performs autocorrelation detection to obtain reflection delay and reflection coefficient.

The communication device, the system and the method for processing the signal provided by the embodiments of the present invention use the fixed reflection delay and the corresponding reflection coefficient in the communication link to eliminate the reflection crosstalk caused by the reflected signal and improve the quality of the communication.

A person skilled in the art can understand that all or part of the steps of implementing the foregoing method embodiments may be performed by hardware related to program instructions, and the foregoing program may be stored in a computer readable storage medium, 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.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, and not The invention is described in detail with reference to the foregoing embodiments, and those of ordinary skill in the art should understand that the technical solutions described in the foregoing embodiments may be modified, or some or all of the technologies may be modified. The features are equivalent to those of the embodiments of the present invention.

Claims

Claim

A communication device, wherein the communication device comprises:

a receiving port for receiving a signal from a communication link;

Processing means for canceling crosstalk in the signal from the communication link based on a reflection delay of the signal in the communication link and a reflection coefficient corresponding to the reflection delay, the reflection delay being A delay between the reflected signal and the unreflected signal, the reflection coefficient being the ratio between the amplitude of the reflected signal and the amplitude of the unreflected signal.

2. The communication device according to claim 1, wherein the processing component is specifically configured to:

Using the reflection delay as a filtering delay of the filtering process, using a negative value of the reflection coefficient corresponding to the reflection delay as a filter coefficient of the filtering process, according to the filtering delay and the filter coefficient, the communication is from the communication The signal of the link is filtered to eliminate crosstalk in the signal from the communication link.

The communication device according to claim 1 or 2, wherein the processing component is specifically configured to:

Filtering processing according to the reflection delay Ί\ and the reflection coefficient to eliminate the crosstalk signal di(t) in d^t+T, where (!^+^ is received from the communication link at time t+T\ The unfiltered signal, the signal received from the communication link and filtered by the wave at time t, the reflection delay Ί\ is the reflected signal sent by the opposite end of the communication link a delay between the unreflected signal transmitted by the opposite end of the communication link, the reflection coefficient being the amplitude of the reflected signal transmitted by the opposite end of the communication link and by the communication link The ratio between the amplitudes of the unreflected signals sent by the peer; and/or,

Filtering is performed according to the reflection delay Τ ₂ and the reflection coefficient R ₂ to eliminate the crosstalk signal R ₂ . d ₂ (t) in (1^+ T ₂ ), where d^t+T is received at t+T ₂ And the unfiltered signal from the communication link, d ₂ (t) is a signal sent locally to the communication link, and the reflection delay T ₂ is a reflected signal transmitted locally and A delay between signals that are not locally reflected, the reflection coefficient R ₂ being the ratio between the amplitude of the locally transmitted reflected signal and the amplitude of the locally unreflected signal.

The communication device according to claim 2 or 3, wherein the processing component is further configured to:

Obtaining a reflected signal according to a reflection delay and a reflection coefficient corresponding to the reflection delay; and performing a decision process on the filtered signal;

Multiplying the reflected signal and the signal subjected to the decision processing, and conjugate the result of the multiplication; performing autocorrelation detection on the filtered signal and the conjugated signal; performing the autocorrelation detection result Fast Fourier transform FFT, obtaining a frequency domain signal after FFT; calculating a beat frequency crosstalk caused by the reflected signal according to a position of a peak point of the frequency domain signal and an intensity of a peak point, and eliminating the filtered Crosstalk of the beat frequency in the processed signal.

5. A communication device according to any one of claims 1 to 4, characterized in that:

The communication device also includes a transmission port;

The sending port is configured to send a first training sequence signal;

The receiving port is further configured to receive a signal that is reflected by the first training sequence signal in the communication link;

The processing component is further configured to: perform auto-correlation detection on the reflected signals of the first training sequence signal and the first training sequence signal to obtain a reflection delay and a reflection coefficient.

6. A communication device according to any one of claims 1 to 4, characterized in that:

The receiving port is further configured to receive a second training sequence signal sent by the peer end;

The processing component is further configured to obtain a reflection delay and a reflection coefficient by performing autocorrelation detection on the locally known second training sequence signal and the second training sequence sent by the opposite end.

The communication device according to any one of claims 1 to 6, wherein the communication device is applied to a single-fiber bidirectional intensity modulation-direct detection communication system.

A communication system, characterized in that the communication system comprises the communication device according to any one of claims 1 to 7.

9. A method of processing a signal, the method comprising:

Receiving a signal from a communication link;

Resolving crosstalk in the signal from the communication link based on a reflection delay of the signal in the communication link and a reflection coefficient corresponding to the reflection delay, the reflection delay being a reflected signal and not The delay between the reflected signals is the ratio between the amplitude of the reflected signal and the amplitude of the unreflected signal.

10. The method according to claim 9, wherein said canceling said reflection delay in said communication link and a reflection coefficient corresponding to said reflection delay cancel said said communication link Crosstalk in the signal, including:

The method according to claim 9 or 10, wherein the removing the reflection delay in the communication link according to a signal and the reflection coefficient corresponding to the reflection delay eliminates the coming from the communication chain Crosstalk in the signal of the road, including:

Filtering is performed according to the reflection delay Ί\ and the reflection coefficient to eliminate the crosstalk signal d!(t) in d^t+T, where (!^+^ is the time from the communication link received at t+ time Filtered signal, (0 is the signal received from the communication link at time t and has been filtered, the reflection delay Ί\ is the reflected signal sent by the opposite end of the communication link a delay between the unreflected signal transmitted by the opposite end of the communication link, the reflection coefficient being the amplitude of the reflected signal transmitted by the opposite end of the communication link and by the communication link The ratio between the amplitudes of the unreflected signals sent by the peer; and/or,

Filtering is performed according to the reflection delay Τ ₂ and the reflection coefficient R ₂ to eliminate the crosstalk signal R ₂ . d ₂ (t) in (1^+ T ₂ ), where d^t+T is received at t+T ₂ And the unfiltered signal from the communication link, d ₂ (t) is a signal sent locally to the communication link, and the reflection delay T ₂ is a reflected signal transmitted locally and a delay between locally unreflected signals, the reflection coefficient R ₂ being the amplitude of the locally transmitted reflected signal and the local unreflected signal The ratio between the magnitudes of the numbers.

12. The method according to claim 10 or 11, wherein the removing the reflection delay in the communication link according to a signal and the reflection coefficient corresponding to the reflection delay eliminates the coming from the communication chain Crosstalk in the signal of the road also includes:

The method according to any one of claims 9 to 12, wherein the method further comprises:

Transmitting a first training sequence signal; receiving a signal reflected by the first training sequence signal in the communication link; performing autocorrelation detection on the reflected signal of the first training sequence signal and the first training sequence signal Reflection delay and reflection coefficient; and / or,

Receiving a second training sequence signal sent by the opposite end; performing a auto-correlation detection using the locally known second training sequence signal and the second training sequence sent by the opposite end to obtain a reflection delay and a reflection coefficient.

14. A method according to any one of claims 9 to 13 wherein:

The method is applied to a single fiber bidirectional intensity modulation-direct detection communication system.