CN115913841B - Data equalization method for equivalent time sampling signal - Google Patents
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Abstract
The invention belongs to the technical field of data equalization methods, and particularly relates to a data equalization method for equivalent time sampling signals, which comprises the following steps: establishing a target continuous time equalizer and processing continuous signals; equivalent time sampling is carried out on the input and output signals of the continuous time equalizer; establishing an equivalent time equalizer and calculating a parameter matrix of the equivalent time equalizer; and processing the equivalent time sampling signal by using the equalizer and the calculated corresponding parameter matrix. The invention adopts a recursion method to establish an equivalent sampling equalizer and calculates a parameter matrix thereof to generate an equivalent sampling equalizer corresponding to the function of the continuous time sampling equalizer and the corresponding relation of parameters between the two equalizers. The invention solves the problem that the equivalent time sampling data cannot be subjected to signal equalization, and can be used for signal equalization processing of equipment such as sampling oscilloscopes and the like.
Description
Technical Field
The invention belongs to the technical field of data equalization methods, and particularly relates to a data equalization method for equivalent time sampling signals.
Background
When the rate of the digital signal is relatively high and the transmission distance is relatively long, the loss of the transmission channel for different frequency components is different, and especially for high frequency components, the loss is relatively large, which can seriously distort the signal. In order to increase the data rate without significantly increasing the cost of the transmission channel design, some signal conditioning techniques are selectively used at the transmitting and receiving ends to compensate for the effect of high frequency component loss on the signal shape. The technique used at the transmitting end is commonly referred to as pre-emphasis or De-emphasis (De-Emphasis), while the technique used at the receiving end is equalization (Equalization).
The conventional equalizer generally has CTLE (continuous TIME LINEAR equalization), FFE (feed forward equalization), DFE (decision feedback equalization) or the like based on the filter principle. These equalizers either require that the processed signal be a continuous sampling result or use a pattern lock mode, which is not possible with equivalent time sampled signals.
Disclosure of Invention
Aiming at the technical problems that the equalizer requires the processed signals to be obtained by continuous sampling or uses a code pattern locking mode, and the equivalent time sampling signals cannot be processed, the invention provides a data equalization method for the equivalent time sampling signals, which can be applied to high-frequency waveform compensation, waveform/eye diagram quality improvement of equipment such as sampling oscilloscopes and the like.
In order to solve the technical problems, the invention adopts the following technical scheme:
a data equalization method for an equivalent time sampled signal, comprising the steps of:
S1, establishing a target continuous time equalizer, setting related parameters of the continuous time equalizer, and processing continuous signals;
S2, performing equivalent time sampling on input and output signals of the continuous time equalizer in the S1;
s3, establishing an equivalent time equalizer, and calculating a parameter matrix of the equivalent time equalizer by using the data acquired in the S2 as input and input values of the equivalent time equalizer;
S4, processing the equivalent time sampling signal by utilizing the equalizer established in the S3 and the corresponding parameter matrix obtained through calculation.
The relevant parameters of the continuous time equalizer in S1 include channel rate, loss and frequency domain response.
The continuous time equalizer in S1 is a continuous time linear equalizer, a forward feedback equalizer or a decision feedback equalizer.
The method for processing the continuous signal in the S1 comprises the following steps: the signals NRZ and PAM4 are continuously sampled to obtain u (t) and are subjected to equalization processing, and a result y (t) is output.
The sampling mode of the equivalent time sampling in S2 is sequential sampling or random sampling.
The method for calculating the parameter matrix in the step S3 is as follows: iterating the equivalent time equalizer node matrix x n by using the data acquired in S2 as an input value u (t n) of the equivalent time equalizer:
xn(t)＝αfNL[Axn(t-1)+Bu(t-1)]+(1-α)xn(t-1)
The f NL is a nonlinear function, the t is acquisition point time, the alpha is an iteration proportion, and the A, B respectively represents the input value and the connection weights among the intermediate nodes;
The formula y is established (t n)＝Wxn and solved to obtain the parameter matrix W.
The method for processing the equivalent time sampling signal in the S4 is as follows: establishing an equivalent time equalizer by using the equalizer established in the S3 and the corresponding parameter matrix W obtained by calculation, and obtaining an equivalent time sampling signal processing result y out
yout＝Wx。
Compared with the prior art, the invention has the beneficial effects that:
The invention adopts a recursion method to establish an equivalent sampling equalizer and calculates a parameter matrix thereof to generate an equivalent sampling equalizer corresponding to the function of the continuous time sampling equalizer and the corresponding relation of parameters between the two equalizers. The invention solves the problem that the equivalent time sampling data cannot be subjected to signal equalization, and can be used for signal equalization processing of equipment such as sampling oscilloscopes and the like.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It will be apparent to those skilled in the art from this disclosure that the drawings described below are merely exemplary and that other embodiments may be derived from the drawings provided without undue effort.
The structures, proportions, sizes, etc. shown in the present specification are shown only for the purposes of illustration and description, and are not intended to limit the scope of the invention, which is defined by the claims, so that any structural modifications, changes in proportions, or adjustments of sizes, which do not affect the efficacy or the achievement of the present invention, should fall within the scope of the invention.
FIG. 1 is a diagram of an equivalent time sampling and eye diagram formation process according to the present invention;
FIG. 2 is a flow chart of the steps of the present invention;
FIG. 3 is a graph of the continuous and equivalent time equalizer input signals of the present invention;
fig. 4 is a graph of the output results of the continuous and equivalent time equalizer of the present invention.
Detailed Description
For the purposes of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions in the embodiments of the present application will be clearly and completely described below, and it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments, and these descriptions are only for further illustrating the features and advantages of the present application, not limiting the claims of the present application; all other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.
The following describes in further detail the embodiments of the present invention with reference to the drawings and examples. The following examples are illustrative of the invention and are not intended to limit the scope of the invention.
In this embodiment, as shown in fig. 1, sampling is performed in different bit periods of an input digital signal, sampling time points thereof are sequentially increased by a delay of a certain time, and for a communication signal, there is a certain randomness, such as Pseudo-random-Random Binary Sequence (PRBS), and an eye pattern is formed by the acquisition result. The data of the eye patterns obtained by equivalent time sampling has discontinuous ordinate between two adjacent time points, and each eye pattern is directly irrelevant, so that the data processing methods such as average, filtering, equalization and the like depending on the front and rear time points cannot be performed. The continuous time acquisition forms an eye pattern by overlapping every 3 bits of data, the data points are still continuous, and the processing methods such as average, filtering, equalization and the like are still effective. In order to solve the problem of processing equivalent time sampling data, the present embodiment provides a constant equivalent time equalizer, which can be used for equalizing digital signals in optical and electrical communications, and the specific steps thereof are as shown in fig. 2, and include the following steps:
step 1: and establishing a target continuous time equalizer, setting related parameters including channel rate, loss, frequency domain response and the like, continuously sampling signals (such as NRZ and PAM 4) to obtain u (t), carrying out equalization processing, and outputting a result y (t).
Step 2: and (3) performing equivalent time sampling on the input and output signals of the continuous time equalizer in the step (1) to obtain u (t n)、y(tn).
Step 3: creating an equivalent time equalizer: iterating the equivalent time equalizer node matrix x n by using the data acquired in the step 2 as an input value u (t n) of the equivalent time equalizer:
xn(t)＝αfNL[Axn(t-1)+Bu(t-1)]+(1-α)xn(t-1)
Wherein f NL is a nonlinear function, t is acquisition point time, alpha is iteration proportion, and A, B respectively represents the input value and the connection weights between the intermediate node and the intermediate node. Establishing a formula y (t n)＝Wxn and solving to obtain a parameter matrix W
Step 4: using an equivalent time equalizer: and (3) establishing an equivalent time equalizer by using the equalizer established in the step (3) and the corresponding parameter matrix W obtained by calculation, and obtaining an equivalent time sampling signal processing result y out.
yout＝Wx
Because of the influence of signal rate, channel loss and the like, the quality of the input signal eye diagram of the continuous time equalizer is poor, which is characterized by low line contact ratio and small eye opening, and reflects poor communication quality. The input signal to the equivalent time equalizer is distributed at different phase points of each successive time equalizer input eye pattern as shown in fig. 3.
The output of the result is shown in fig. 4 after the equivalent and continuous time equalizer operation, and it can be seen that the repeatability of the output trace of the continuous time equalizer and the eye opening degree are both obviously improved, which indicates that the communication quality is improved. On the other hand, the output value of the equivalent time equalizer basically coincides with the output of the continuous time equalizer, which indicates that the equivalent time equalizer can be used for equalizing the equivalent time sampling signals, the action effect is equivalent to that of the continuous time equalizer, and the problem that the equivalent time sampling signals cannot be equalized is solved.
Taking CTLE equalizer as an example, the implementation method of the invention is described
1. Establishing a transmit signal
Setting signal data type to prbs, bit number to 2 10 -1, amplitude range to + -0.5
2. Establishing a channel
Channel loss 10dB, dc gain, peak gain, etc. are set.
3. Sampling (including continuous time, equivalent time)
Continuous sampling: each bit is used for collecting 1000 sampling points; equivalent collection: each bit delays 1/100bit acquisition as shown in figure 3.
4. Establishing CTLE equalizer and processing continuously collected signals
And inputting impulse response and spectrum response of the system to generate signal eye diagrams before and after processing.
5. Establishing an equivalent sampling equalizer and solving the correlation coefficient
And selecting equivalent time of the CTLE equalizer to acquire corresponding input and output data, and calculating equivalent equalizer parameters.
6. The equivalent time acquisition data is processed using an equivalent equalizer, the results of which are shown in fig. 4.
The preferred embodiments of the present invention have been described in detail, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the spirit of the present invention, and the various changes are included in the scope of the present invention.
Claims (4)
1. A data equalization method for equivalent time sampled signals, characterized by: comprises the following steps:
S1, establishing a target continuous time equalizer, setting related parameters of the continuous time equalizer, and processing continuous signals; the method for processing the continuous signal in the S1 comprises the following steps: continuously sampling signals NRZ and PAM4 to obtain u (t) and carrying out equalization processing, and outputting a result y (t);
S2, performing equivalent time sampling on input and output signals of the continuous time equalizer in the S1;
s3, establishing an equivalent time equalizer, and calculating a parameter matrix of the equivalent time equalizer by using the data acquired in the S2 as input and input values of the equivalent time equalizer;
The method for calculating the parameter matrix in the step S3 is as follows: iterating the equivalent time equalizer node matrix x n by using the data acquired in S2 as an input value u (t n) of the equivalent time equalizer:
xn(t)＝αfNL[Axn(t-1)+Bu(t-1)]+(1-α)xn(t-1)
The f NL is a nonlinear function, the t is acquisition point time, the alpha is an iteration proportion, and the A, B respectively represents the input value and the connection weights among the intermediate nodes;
Establishing a formula y (t n)＝Wxn and solving to obtain a parameter matrix W;
s4, processing the equivalent time sampling signal by utilizing the equalizer established in the S3 and the corresponding parameter matrix obtained by calculation;
The method for processing the equivalent time sampling signal in the S4 is as follows: establishing an equivalent time equalizer by using the equalizer established in the S3 and the corresponding parameter matrix W obtained by calculation, and obtaining an equivalent time sampling signal processing result y out
yout＝Wx。
2. A method of data equalisation for equivalent time sampled signals according to claim 1, wherein: the relevant parameters of the continuous time equalizer in S1 include channel rate, loss and frequency domain response.
3. A method of data equalisation for equivalent time sampled signals according to claim 1, wherein: the continuous time equalizer in S1 is a continuous time linear equalizer, a forward feedback equalizer or a decision feedback equalizer.
4. A method of data equalisation for equivalent time sampled signals according to claim 1, wherein: the sampling mode of the equivalent time sampling in S2 is sequential sampling or random sampling.
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