Signal modulation method, decision feedback equalizer and storage medium

Abstract

The invention provides a signal modulation method, a decision feedback equalizer and a storage medium. The method comprises the following steps: performing amplitude estimation on a modulation signal x (t) to obtain an amplitude estimation value a (t) of a current period; the amplitude estimation values a (t-1), a (t-2),..., a (t-M + 1) and the amplitude estimation value a (t) in the past M-1 periods are balanced, an amplitude balance result z (t) is obtained, and M is an integer larger than 1; the differential phase p (t-i) of the modulation signal x (t) is determined, the differential phase p (t-i) is a differential phase result of x (t) and x (t-i), and i is an integer larger than 0; balancing the differential phases p (t-1), p (t-2),..., p (t-N + 1) in the past N-1 periods to obtain an actual differential phase w (t), N being an integer greater than 1; recovering the actual differential phase w (t) to a normal signal phase v (t); and demodulating to obtain a modulation result y (t) corresponding to the modulation signal x (t) according to the amplitude equalization result z (t) and the signal phase v (t). According to the signal modulation method provided by the invention, the equalization performance of the decision feedback equalizer can be improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of wireless communication, and particularly relates to a signal modulation method, a decision feedback equalizer and a storage medium. BACKGROUND

[0002] In wireless communication, an equalizer is used to eliminate the inter-symbol interference of a signal and the distortion of a channel response. A decision feedback equalizer (hereinafter referred to as DFE) as shown in FIG. 1 can include a feedforward filter, a decision device and a feedback filter, and is one of the most commonly used time-domain equalizers in the field. The DFE equalization calculation process is as follows: a signal sample x(t) at time t is filtered by a feedforward filter to obtain x'(t), and is added to the output y'(t-1) of a feedback filter at time t-1 to obtain w(t), and after being judged by a modulation signal decision device, a decision result y(t) is obtained, and y(t) is input into a feedback filter for filtering, which is used for equalization calculation of the next signal sample. Figure 1

[0003] However, the equalization performance of the current decision feedback equalizer is poor, and the performance is not good in a fast fluctuating channel environment, and is greatly affected by the past decision results, and an error decision will cause error propagation, which directly affects the subsequent equalization result.

[0004] Therefore, how to improve the equalization performance of the decision feedback equalizer is a problem to be solved. SUMMARY

[0005] In view of the problems existing in the prior art, a signal modulation method, a decision feedback equalizer and a storage medium are provided, and the equalization performance of the decision feedback equalizer can be improved by using the method, the decision feedback equalizer and the storage medium.

[0006] The application provides the following solutions.

[0007] In a first aspect, the application provides a signal modulation method, which is applied to a decision feedback equalizer, and the method comprises the following steps.

[0008] Performing amplitude estimation on the modulation signal x(t) to obtain an amplitude estimation value a(t) of a current period;

[0009] Equalizing the amplitude estimation values a(t-1), a(t-2), …, a(t-M+1) of the past M-1 periods and the amplitude estimation value a(t) to obtain an amplitude equalization result z(t), M is an integer greater than 1;

[0010] Determining a differential phase p(t-i) of the modulation signal x(t), the differential phase p(t-i) being a differential phase result of x(t) and x(t-i), i being an integer greater than 0.​

[0011] equalizing the differential phases p(t-1), p(t-2), …, p(t-N+1) of the past N-1 periods to obtain an actual differential phase w(t), N being an integer greater than 1;

[0012] restoring the actual differential phase w(t) into a normal signal phase v(t);

[0013] demodulating to obtain a modulation result y(t) corresponding to the modulation signal x(t) according to the amplitude equalization result z(t) and the signal phase v(t).

[0014] In some possible embodiments, the amplitude equalization result z(t) is obtained by equalizing the amplitude estimation value a(t) and the amplitude estimation values a(t-1), a(t-2), …, a(t-M+1) of the past M-1 periods, including:

[0015] equalizing the amplitude estimation value a(t) and the amplitude estimation values a(t-1), a(t-2), …, a(t-M+1) of the past M-1 periods according to the amplitude reliabilities f(t-1), f(t-2), …, f(t-M+1) to obtain the amplitude equalization result z(t);

[0016] wherein the amplitude reliability f(t-M+1) is used to indicate a reliability degree of the amplitude estimation value a(t-M+1), and the amplitude reliability f(t-M+1) is determined according to the modulation result y(t-M+1) and the amplitude equalization result z(t-M+1) of the past M-1 period.

[0017] In some possible embodiments, the amplitude reliability f(t-M+1) is calculated by the following formula:

[0018] f(t-M+1) = ha*z(t-M+1)

[0019]

[0020] wherein ha is a weighting coefficient, and when a>thd1, ha is set as 0 or a weight greater than 0 and less than q, otherwise ha is set as 1 or a weight greater than q, q being greater than 0, and thd1 being a preset coefficient.

[0021] In some possible embodiments, the amplitude equalization result z(t) is calculated by the following formula:

[0022]

[0023] In some possible embodiments, the actual differential phase w(t) is obtained by equalizing the differential phases p(t-1), p(t-2), …, p(t-N+1) of the past N-1 periods, including:

[0024] The actual differential phase w(t) is obtained by equalizing the differential phases p(t-1), p(t-2), …, p(t-N+1) of the past N-1 periods according to the differential phase reliabilities e(t-1), e(t-2), …, e(t-N+1).

[0025] The differential phase reliability e(t-N+1) is used to indicate the reliability degree of the differential phase p(t-N+1), and the differential phase reliability e(t-N+1) is determined according to the modulation result y(t-N+1) of the past N-1 period, the actual differential phase w(t-N+1), and the signal phase v(t-N+1).

[0026] In some possible embodiments, the differential phase reliability e(t-N+1) is calculated by the following formula:

[0027] e(t-N+1) = hp*w(t-N+1)

[0028] θ = angle(y(t) * conj(v(t)))

[0029] wherein, when θ>thd2, hp is 0 or greater than 0 and less than w, otherwise hp is 1 or greater than w, w is greater than 0, and thd2 is a preset coefficient.

[0030] In some possible embodiments, the actual differential phase w(t) is calculated by the following formula:

[0031]

[0032] In some possible embodiments, the amplitude estimation value a(t) of the current period is obtained by performing amplitude estimation on the modulation signal x(t), including:

[0033] The gain value g of the current signal amplitude is obtained according to the channel estimation result.

[0034] The amplitude estimation value a(t) is calculated by the following formula:

[0035]

[0036] In some possible embodiments, the differential phase p(t-i) of the modulation signal x(t) can be calculated by the following formula:

[0037] β = angle(x(t) * conj(x(t-i)))

[0038] p(t-i) = e -iβ

[0039] The signal phase v(t) can be calculated by the following formula:

[0040] v(t) = angle(x(t-1)) + angle(w(t))

[0041] In some possible embodiments, the modulation signal x(t) is a QAM modulation complex signal received at time t, and the modulation result y(t) is a complex symbol on a quadrature amplitude modulation (QAM) constellation diagram.

[0042] In a second aspect, the present application provides a decision feedback equalizer, comprising:

[0043] An amplitude estimator configured to perform amplitude estimation on the modulation signal x(t) to obtain an amplitude estimation value a(t) of a current period;

[0044] An amplitude equalizer configured to equalize the amplitude estimation values a(t-1), a(t-2), …, a(t-M+1) of the past M-1 periods and the amplitude estimation value a(t) to obtain an amplitude equalization result z(t), M being an integer greater than 1;

[0045] A phase differentiator configured to determine a differential phase p(t-i) of the modulation signal x(t), the differential phase p(t-i) being a differential phase result of x(t) and x(t-i), i being an integer greater than 0;

[0046] A differential phase equalizer configured to equalize the differential phases p(t-1), p(t-2), …, p(t-N+1) of the past N-1 periods to obtain an actual differential phase w(t), N being an integer greater than 1;

[0047] A phase restorer configured to restore the actual differential phase w(t) into a normal signal phase v(t);

[0048] A demodulator configured to demodulate the modulation result y(t) corresponding to the modulation signal x(t) according to the amplitude equalization result z(t) and the signal phase v(t).

[0049] In some possible embodiments, the decision feedback equalizer further comprises:

[0050] An amplitude reliability estimator configured to determine an amplitude reliability f(t-M+1) according to the modulation result y(t-M+1) of the past M-1 period and the amplitude equalization result z(t-M+1);

[0051] An amplitude equalizer is configured to equalize the amplitude estimation values a(t-1), a(t-2),..., a(t-M+1) of the past M-1 periods and the amplitude estimation value a(t) according to the amplitude reliabilities f(t-1), f(t-2),..., f(t-M+1) to obtain an amplitude equalization result z(t).

[0052] In some possible embodiments, the decision feedback equalizer further includes:

[0053] A differential phase reliability estimator is configured to determine a differential phase reliability e(t-N+1) according to the modulation result y(t-N+1) of the past N-1 period, the actual differential phase w(t-N+1) and the signal phase v(t-N+1).

[0054] A differential phase equalizer is configured to equalize the differential phases p(t-1), p(t-2),..., p(t-N+1) of the past N-1 periods according to the differential phase reliabilities e(t-1), e(t-2),..., e(t-N+1) to obtain the actual differential phase w(t).

[0055] In a third aspect, the present application provides a computer readable storage medium, which stores a program, and when the program is executed by a multi-core processor, the multi-core processor performs the signal modulation method described above.

[0056] The embodiments of the present application can estimate and overcome the channel environment changes caused by multipath, frequency offset jitter and the like by respectively equalizing the amplitude and phase of the modulation signal and using the equalization estimation output results of multiple time intervals, and can improve the equalization performance of the equalizer, especially in a fast fluctuating channel environment, and the past decision results have less influence, and the error propagation caused by the past erroneous decisions is less.

[0057] Other advantages of the present application will be described in more detail in conjunction with the following description and drawings.

[0058] It should be understood that the above description is only a summary of the technical solutions of the present application, so as to enable a clearer understanding of the technical means of the present application, and thus the content of the description can be implemented. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the following specific embodiments of the present application are described by way of example. BRIEF DESCRIPTION OF DRAWINGS

[0059] The advantages and benefits described herein, as well as other advantages and benefits, will be apparent to those of ordinary skill in the art upon reading the following detailed description of exemplary embodiments. The drawings are for purposes of illustrating exemplary embodiments only and are not to be construed as limiting the present application. In the drawings:

[0060] Figure 1A schematic diagram of a signal adjustment method provided for an embodiment of the present application;

[0061] Figure 2 A flowchart of a signal modulation method provided for an embodiment of the present application;

[0062] Figure 3 A schematic diagram of another signal modulation method provided for an embodiment of the present application;

[0063] Figure 4 A schematic diagram of a decision feedback equalizer provided for an embodiment of the present application.

[0064] In the drawings, identical or similar reference signs indicate identical or similar parts. DETAILED DESCRIPTION

[0065] Exemplary embodiments of the present application will be described in detail with reference to the drawings. Although exemplary embodiments of the present application are shown in the drawings, it should be understood that the present application can be embodied in various forms without being limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present application will be thorough and complete, and will fully convey the scope of the present application to those skilled in the art.

[0066] In the description of embodiments of the present application, it should be understood that terms such as "include" or "have" are intended to indicate that there can be additional features, numbers, steps, actions, components, parts, or combinations thereof, in addition to those disclosed in the specification, and do not exclude the presence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0067] Unless otherwise specified, " / " means or, for example, A / B can mean A or B; "and / or" herein is only a description of the association relationship of the associated objects, and means that there can be three relationships, for example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone.

[0068] The terms "first", "second", and the like are used only to distinguish the same or similar technical features, and cannot be understood as indicating or implying relative importance or quantity of the technical features. Therefore, the technical features defined by "first", "second", and the like can explicitly or implicitly include one or more of the technical features. In the description of embodiments of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more than two.

[0069] In addition, it should be further noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0070] A decision feedback equalizer (DFE) as shown in Figure 1 may include a feedforward filter, a decision device and a feedback filter, and is one of the most commonly used time domain equalizers in the art. The DFE equalization calculation process is as follows: the signal sample x(t) at time t is filtered by the feedforward filter to obtain x'(t), which is added to the feedback filter output y'(t-1) at the previous time t-1 to obtain w(t), and after modulation signal decision, the decision result y(t) is obtained. y(t) is input into the feedback filter for filtering, which is used for equalization calculation of the next signal sample. However, the current DFE has the disadvantage that the equalization performance for quadrature amplitude modulation (QAM) signals is poor, the performance is not good in a fast fluctuating channel environment, and is greatly affected by the past decision results. False decisions will cause error propagation, which will directly affect the subsequent equalization results.

[0071] To solve the above technical problems, the present application provides a signal modulation method, a decision feedback equalizer and a storage medium. By using the method, device and computer readable storage medium, the equalization performance of the decision feedback equalizer can be improved.

[0072] The present application will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0073] As shown in Figure 2 , the present application provides a signal modulation method, which is applied to a decision feedback equalizer, comprising:

[0074] S201: amplitude estimation is performed on the modulation signal to obtain an amplitude estimation value of the current period.

[0075] It should be noted that the modulation signal x(t) in the embodiments of the present application can be a QAM modulation complex signal received at time t, or other types of modulation signals, which are not limited in the embodiments of the present application.

[0076] As shown in Figure 3 , the step S201 in the embodiments of the present application can be implemented by Figure 3The amplitude estimator in this embodiment performs amplitude estimation on the modulated signal x(t) to obtain the amplitude estimate a(t) for the current period. Furthermore, the amplitude estimator in this embodiment can store the amplitude estimates a(t-1), a(t-2), ..., a(t-M+1) for the past M-1 periods and output these estimates to the amplitude equalizer. In this embodiment, M is an integer greater than 1, such as 2, 3, 4, etc. The specific value of M can be set according to the usage scenario and testing experience.

[0077] It should be noted that, in the embodiments of this application, the gain value g of the current signal amplitude can be obtained based on the channel estimation result, and the amplitude estimate a(t) can be calculated using the following formula:

[0078]

[0079] It should be noted that the amplitude estimate a(t) in the embodiments of this application can also be calculated in other ways, and the embodiments of this application do not limit it here.

[0080] S202: Equalize the amplitude estimates and amplitude estimates of the past M-1 periods to obtain the amplitude equalization result.

[0081] like Figure 3 As shown, step S202 in this embodiment can be performed by... Figure 3 The amplitude equalizer in this embodiment completes the process. The amplitude equalizer in this application can obtain the amplitude equalization result z(t) by equalizing the amplitude estimates a(t-1), a(t-2), ..., a(t-M+1) and the amplitude estimate a(t) of the past M-1 cycles.

[0082] As one possible implementation, this application can equalize the amplitude estimates a(t-1), a(t-2), ..., a(t-M+1) and the amplitude estimate a(t) over the past M-1 cycles based on the amplitude reliability f(t-1), f(t-2), ..., f(t-M+1), to obtain the amplitude equalization result z(t). Here, the amplitude reliability f(t-M+1) indicates the reliability of the amplitude estimate a(t-M+1), and the amplitude reliability f(t-M+1) is determined based on the modulation result y(t-M+1) and the amplitude equalization result z(t-M+1) over the past M-1 cycles.

[0083] like Figure 3 As shown, the amplitude reliability in the embodiments of this application can be achieved through... Figure 3The amplitude reliability estimator is used to calculate it. The amplitude reliability estimator can determine the amplitude reliability f(t-M+1) based on the modulation result y(t-M+1) and the amplitude equalization result z(t-M+1) of the past M-1 cycles, and store the amplitude reliability f(t-1), f(t-2), ..., f(t-M+1) of the past M-1 cycles, and output it to the amplitude equalizer.

[0084] As an example, the amplitude reliability estimator in this application embodiment can calculate the amplitude reliability f(t-M+1) through the following steps:

[0085] Step A: Calculate the amplitude m of the demodulation result y(t-M+1) = y(t-M+1).

[0086] Step B: Obtain the ratio α of m and z(t) using the following formula.

[0087]

[0088] Step C: Output f(t-M+1) = ha*z(t-M+1).

[0089] Where ha is the weighting coefficient, and when α>thd1, the z(t) estimate is considered unreliable. Let ha be 0 or greater than 0 and less than q. Otherwise, the z(t) estimate is considered reliable. Let ha be 1 or greater than q. q is greater than 0. thd1 is a preset coefficient that can be set according to the usage scenario and testing experience.

[0090] In this embodiment, the amplitude equalization result z(t) can be calculated using the following formula:

[0091]

[0092] It should be noted that the amplitude equalization result z(t) in the embodiments of this application can also be calculated in other ways, and the embodiments of this application do not limit it here.

[0093] S203: Determine the differential phase of the modulated signal.

[0094] like Figure 3 As shown, step S203 in this embodiment can be achieved through... Figure 3The phase differential in this embodiment determines the differential phase p(ti) of the modulated signal x(t), and then outputs the differential phases p(t-1), p(t-2), ..., p(t-N+1) of the past N-1 cycles to the differential phase equalizer. In this embodiment, the differential phase p(ti) is the differential phase result of x(t) and x(ti), where i is an integer greater than 0. N is an integer greater than 1, such as 2, 3, or 4. N can be set based on the channel impulse response (CIR) result estimated by the channel, or based on the usage scenario and testing experience.

[0095] In this embodiment of the application, the differential phase p(ti) of the modulation signal x(t) can be calculated using the following formula:

[0096] β=angle(x(t)*conj(x(ti)))

[0097] p(ti=e -iβ

[0098] It should be noted that the differential phase p(ti) in the embodiments of this application can also be calculated in other ways, and the embodiments of this application do not limit it here.

[0099] S204: Equalize the differential phase over the past N-1 cycles to obtain the actual differential phase.

[0100] like Figure 3 As shown, step S204 in this embodiment can be performed by... Figure 3 The differential phase equalizer in this embodiment can receive the differential phases p(t-1), p(t-2), ..., p(t-N+1) of the past N-1 periods sent by the phase differential, and equalize the differential phases p(t-1), p(t-2), ..., p(t-N+1) of the past N-1 periods to obtain the actual differential phase w(t).

[0101] As one possible implementation, embodiments of this application can equalize the differential phases p(t-1), p(t-2), ..., p(t-N+1) of the past N-1 cycles based on the differential phase reliability e(t-1), e(t-2), ..., e(t-N+1) to obtain the actual differential phase w(t). The differential phase reliability e(t-N+1) indicates the reliability of the differential phase p(t-N+1), and is determined based on the modulation result y(t-N+1) of the past N-1 cycles, the actual differential phase w(t-N+1), and the signal phase v(t-N+1).

[0102] As shown in Figure 3 , the differential phase reliability in the embodiment of the present application can be calculated by the differential phase reliability estimator in Figure 3 . The differential phase reliability estimator can make reliability estimation on the signal phase v(t-N+1) recovered by the phase restorer according to the modulation result y(t-N+1) of the past N-1 periods, make corresponding processing on the actual differential phase w(t-N+1) according to the estimation result, obtain the estimation result e(t), and store the past N-1 estimation results e(t-1), e(t-2), …, e(t-N+1) and output to the differential phase equalizer.

[0103] In the embodiment of the present application, e(t) is the complex result output after the differential phase reliability estimation on w(t), as an example, the differential phase reliability estimator in the embodiment of the present application can calculate the differential phase reliability e(t-N+1) by the following steps:

[0104] Step A, calculate the differential signal d=y(t-N+1)*conj(v(t-N+1)) of y(t-N+1) and w(t-N+1).

[0105] Step B, obtain the phase difference amount θ=angle(d).

[0106] Step C, output e(t-N+1)=hp*w(t-N+1), and hp is the weighting coefficient.

[0107] Wherein, when θ>thd2, hp is 0 or greater than 0 and less than the weight of w, otherwise hp is 1 or greater than the weight of w, w is greater than 0, and thd2 is a preset coefficient. The value range of thd2 and hp is an empirical value, which is set according to the use scene and test experience.

[0108] In the embodiment of the present application, the actual differential phase w(t) can be the equalized complex result of p(t), and the actual differential phase w(t) can be calculated by the following formula:

[0109]

[0110] It should be noted that the actual differential phase w(t) in the embodiment of the present application can also be calculated by other ways, which is not limited in the embodiment of the present application.

[0111] S205: restore the actual differential phase to the normal signal phase.

[0112] As shown in Figure 3 , step S205 in the embodiment of the present application can be calculated by the actual differential phase recovery unit in Figure 3The phase recovery is completed by the phase recovery device in the equalizer. v(t) is the actual phase obtained by differential phase recovery. As an example, the phase recovery device can recover the actual differential phase w(t) into the normal signal phase v(t) by the following formula:

[0113] v(t) = angle(x(t-1)) + angle(w(t))

[0114] It should be noted that the signal phase v(t) in the embodiments of the present application can also be calculated by other ways, which are not limited herein.

[0115] S206: demodulating the modulation result corresponding to the modulation signal according to the amplitude equalization result and the signal phase.

[0116] In the embodiments of the present application, when the modulation signal x(t) can be a QAM modulation complex signal received at time t, the modulation result y(t) can be a QAM complex signal demodulated at time t, i.e., a complex symbol on a QAM modulation constellation. In actual applications, the decision can adopt a simple hard decision manner, or a commonly used log-likelihood ratio estimation LLR (Log-Likelihood Ratio) manner, etc.

[0117] In summary, the embodiments of the present application estimate and overcome the channel environment changes caused by multipath, frequency offset jitter, etc. by respectively equalizing the amplitude and phase of the modulation signal, and using the equalization estimation output results of multiple time intervals, and the reliability estimation of the equalization estimation output results can avoid the error propagation caused by the error decision, and can improve the equalization performance of the equalizer, especially in the fast fluctuating channel environment, and the past decision results have less influence, and the past error decision will cause less error propagation.

[0118] In the description of the present specification, the description with reference to the terms "some possible embodiments", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiments or examples are contained in at least one embodiment or example of the present application, and the above terms do not necessarily represent the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the present specification and the features of the different embodiments or examples without contradiction.

[0119] With respect to the method flowcharts of the embodiments of the present application, certain operations are described as distinct steps performed in a certain order. Such flowcharts are illustrative and not limiting. Certain steps described herein can be grouped together and performed in a single operation, or certain steps can be split into multiple sub-steps, and certain steps can be performed in an order different from that shown herein. The individual steps shown in the flowcharts can be implemented in any manner by any circuitry structure and / or tangible mechanism (e.g., by software running on a computer device, hardware (e.g., a processor or a chip-implemented logic function), etc., and / or any combination thereof).

[0120] Those skilled in the art can understand that, in the method described in the foregoing specific embodiments, the writing order of the steps does not mean a strict execution order, and the specific execution order of the steps should be determined according to their functions and possible inherent logic.

[0121] According to the signal modulation method provided in the foregoing embodiments, the embodiments of the present application further provide a decision feedback equalizer.

[0122] As shown in Figure 4 The decision feedback equalizer provided by the embodiments of the present application includes:

[0123] An amplitude estimator 100 is configured to perform amplitude estimation on the modulation signal x(t) to obtain an amplitude estimation value a(t) of a current period;

[0124] An amplitude equalizer 200 is configured to perform equalization on the amplitude estimation values a(t-1), a(t-2), …, a(t-M+1) of the past M-1 periods and the amplitude estimation value a(t) to obtain an amplitude equalization result z(t), where M is an integer greater than 1.

[0125] A phase differentiator 300 is configured to determine a differential phase p(t-i) of the modulation signal x(t), where the differential phase p(t-i) is a differential phase result of x(t) and x(t-i), and i is an integer greater than 0.

[0126] A differential phase equalizer 400 is configured to perform equalization on the differential phases p(t-1), p(t-2), …, p(t-N+1) of the past N-1 periods to obtain an actual differential phase w(t), where N is an integer greater than 1.

[0127] A phase restorer 500 is configured to restore the actual differential phase w(t) into a normal signal phase v(t).

[0128] A demodulator 600 is configured to demodulate, according to the amplitude equalization result z(t) and the signal phase v(t), a modulation result y(t) corresponding to the modulation signal x(t).

[0129] As a possible implementation, the decision feedback equalizer in the embodiment of the present application further comprises: an amplitude reliability estimator configured to determine an amplitude reliability f(t-M+1) according to the modulation result y(t-M+1) and the amplitude equalization result z(t-M+1) of the past M-1 periods. An amplitude equalizer configured to equalize the amplitude estimation value a(t-1), a(t-2), …, a(t-M+1) of the past M-1 periods and the amplitude estimation value a(t) according to the amplitude reliabilities f(t-1), f(t-2), …, f(t-M+1), and obtain the amplitude equalization result z(t).

[0130] As a possible implementation, the amplitude reliability f(t-M+1) is calculated by the following formula:

[0131] f(t-M+1) = ha * z(t-M+1)

[0132]

[0133] where ha is a weighting coefficient, and when a>thd1, ha is set to 0 or a weight greater than 0 and less than q, otherwise ha is set to 1 or a weight greater than q, q is greater than 0, and thd1 is a preset coefficient.

[0134] As a possible implementation, the amplitude equalization result z(t) is calculated by the following formula:

[0135]

[0136] As a possible implementation, the decision feedback equalizer in the embodiment of the present application further comprises: a differential phase reliability estimator configured to determine a differential phase reliability e(t-N+1) according to the modulation result y(t-N+1), the actual differential phase w(t-N+1), and the signal phase v(t-N+1) of the past N-1 periods. A differential phase equalizer configured to equalize the differential phase p(t-1), p(t-2), …, p(t-N+1) of the past N-1 periods according to the differential phase reliabilities e(t-1), e(t-2), …, e(t-N+1), and obtain the actual differential phase w(t).

[0137] As a possible implementation, the differential phase reliability e(t-N+1) is calculated by the following formula:

[0138] e(t-N+1) = hp * w(t-N+1)

[0139] θ = angle (y(t) * conj (v(t)))

[0140] wherein, when θ>thd2, hp is set as 0 or a weight greater than 0 and less than w, otherwise hp is set as 1 or a weight greater than w, w is greater than 0, and thd2 is a preset coefficient.

[0141] As a possible implementation, the actual differential phase w(t) is calculated by the following formula:

[0142]

[0143] As a possible implementation, the amplitude estimator is configured to obtain a gain value g of a current signal amplitude according to a channel estimation result, and to calculate an amplitude estimation value a(t) by the following formula:

[0144]

[0145] As a possible implementation, the differential phase p(t-i) of the modulation signal x(t) can be calculated by the following formula:

[0146] β=angle(x(t)*conj(x(t-i)))

[0147] p(t-i)=e -iβ

[0148] The signal phase v(t) can be calculated by the following formula:

[0149] v(t)=angle(x(t-1))+angle(w(t))

[0150] In the embodiments of the present application, the modulation signal x(t) can be a QAM modulation complex signal received at time t, and the modulation result y(t) can be a complex symbol on a quadrature amplitude modulation (QAM) constellation diagram.

[0151] It should be noted that the device in the embodiments of the present application can implement each process of the embodiments of the foregoing method, and achieve the same effects and functions, which will not be described here.

[0152] According to some embodiments of the present application, a non-volatile computer storage medium of a signal modulation method is provided, and computer executable instructions are stored on the non-volatile computer storage medium, the computer executable instructions are configured to execute the method described in the above embodiments when executed by a processor.

[0153] Computer-readable media includes permanent and non-permanent, movable and non-movable media that can implement information storage by any method or technology. The information can be computer-readable instructions, data structures, program modules or other data. Examples of computer-readable storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory, read-only memory, electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical storage, magnetic cassette, magnetic tape disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information accessible by a computing device. In addition, although the operations of the methods of the present application are described in a particular order in the accompanying drawings, this does not require or imply that the operations must be performed in that particular order, or that all of the shown operations must be performed to achieve the desired result. In addition, certain steps can be omitted, combined into one step, and / or divided into multiple sub-steps.

[0154] Although the spirit and principles of the present application have been described above with reference to several specific embodiments, it should be understood that the present application is not limited to the disclosed specific embodiments, and the division of aspects does not mean that the features in these aspects cannot be combined. The present application is intended to cover various modifications and equivalent arrangements included in the spirit and scope of the appended claims.

Claims

1. A method of modulating a signal, characterized by, The method is applied to a decision feedback equalizer, and the method comprises: performing amplitude estimation on a modulation signal x(t) to obtain an amplitude estimation value a(t) of a current period; equalizing the amplitude estimation value a(t) and amplitude estimation values a(t-1), a(t-2), …, a(t-M+1) of M-1 previous periods to obtain an amplitude equalization result z(t), M being an integer greater than 1; determining a differential phase p(t-i) of the modulation signal x(t), the differential phase p(t-i) being a differential phase result of x(t) and x(t-i), i being an integer greater than 0; equalizing differential phases p(t-1), p(t-2), …, p(t-N+1) of N-1 previous periods to obtain an actual differential phase w(t), N being an integer greater than 1; restoring the actual differential phase w(t) into a normal signal phase v(t); demodulating the modulation signal x(t) according to the amplitude equalization result z(t) and the signal phase v(t) to obtain a modulation result y(t) corresponding to the modulation signal x(t).

2. The method of claim 1, wherein, The equalizing the amplitude estimation value a(t) and amplitude estimation values a(t-1), a(t-2), …, a(t-M+1) of M-1 previous periods to obtain an amplitude equalization result z(t) comprises: equalizing the amplitude estimation value a(t) and amplitude estimation values a(t-1), a(t-2), …, a(t-M+1) of M-1 previous periods according to amplitude reliabilities f(t-1), f(t-2), …, f(t-M+1) to obtain an amplitude equalization result z(t); wherein the amplitude reliability f(t-M+1) is used to indicate a reliability degree of the amplitude estimation value a(t-M+1), and the amplitude reliability f(t-M+1) is determined according to a modulation result y(t-M+1) and an amplitude equalization result z(t-M+1) of the M-1th previous period.

3. The method of claim 2, wherein, The amplitude reliability f(t-M+1) is calculated by the following formula: f(t-M+1) = ha*z(t-M+1) wherein ha is a weighting coefficient, and when α>thd1, ha is set as 0 or a weight greater than 0 and less than q, otherwise ha is set as 1 or a weight greater than q, q being greater than 0, and thd1 being a preset coefficient.

4. The method of claim 3, wherein, The amplitude equalization result z(t) is calculated by the following formula:

5. The method of claim 1, wherein, The equalizing the differential phases p(t-1), p(t-2), …, p(t-N+1) of N-1 previous periods to obtain an actual differential phase w(t) comprises: equalizing the differential phases p(t-1), p(t-2), …, p(t-N+1) of N-1 previous periods according to differential phase reliabilities e(t-1), e(t-2), …, e(t-N+1) to obtain an actual differential phase w(t); The differential phase reliability e(t-N+1) is used to indicate the reliability of the differential phase p(t-N+1), and is determined according to the modulation result y(t-N+1) of the past N-1th period, the actual differential phase w(t-N+1) and the signal phase v(t-N+1).

6. The method of claim 5, wherein, The differential phase reliability e(t-N+1) is calculated by the following formula: e(t-N+1) = hp*w(t-N+1) θ = angle(y(t)*conj(v(t))) wherein, when θ>thd2, hp is 0 or greater than 0 and less than w, otherwise hp is 1 or greater than w, w is greater than 0, and thd2 is a preset coefficient.

7. The method of claim 6, wherein, The actual differential phase w(t) is calculated by the following formula:

8. The method of claim 1, wherein, The amplitude estimation of the modulation signal x(t) obtains the amplitude estimation value a(t) of the current period, including: According to the channel estimation result, the gain value g of the current signal amplitude is obtained; The amplitude estimation value a(t) is calculated by the following formula:

9. The method of claim 1, wherein, The differential phase p(t-i) of the modulation signal x(t) is calculated by the following formula: β = angle(x(t)*conj(x(t-i))) p(t-i) = e -iβ The signal phase v(t) can be calculated by the following formula: v(t) = angle(x(t-1))+angle(w(t)).

10. The method according to any one of claims 1 to 9, characterized in that, The modulation signal x(t) is a QAM modulation complex signal received at time t, and the modulation result y(t) is a complex symbol on a quadrature amplitude modulation (QAM) constellation diagram.

11. A decision feedback equalizer characterized by Including: An amplitude estimator for amplitude estimation of the modulation signal x(t) to obtain the amplitude estimation value a(t) of the current period; An amplitude equalizer for equalizing the amplitude estimation values a(t-1), a(t-2), …, a(t-M+1) of the past M-1 periods and the amplitude estimation value a(t) to obtain an amplitude equalization result z(t), M being an integer greater than 1; A phase differentiator for determining the differential phase p(t-i) of the modulation signal x(t), the differential phase p(t-i) being the differential phase result of x(t) and x(t-i), i being an integer greater than 0; A differential phase equalizer for equalizing the differential phases p(t-1), p(t-2), …, p(t-N+1) of the past N-1 periods to obtain an actual differential phase w(t), N being an integer greater than 1; A phase restorer for restoring the actual differential phase w(t) to a normal signal phase v(t); A demodulator for demodulating the modulation result y(t) corresponding to the modulation signal x(t) according to the amplitude equalization result z(t) and the signal phase v(t).

12. The decision feedback equalizer of claim 11, wherein, Further comprising: An amplitude reliability estimator for determining the amplitude reliability f(t-M+1) according to the modulation result y(t-M+1) of the past M-1th period and the amplitude equalization result z(t-M+1). The amplitude equalizer is configured to equalize the amplitude estimation value a(t-1), a(t-2), …, a(t-M+1) of the past M-1 periods and the amplitude estimation value a(t) according to the amplitude reliability f(t-1), f(t-2), …, f(t-M+1) to obtain an amplitude equalization result z(t).

13. The decision feedback equalizer of claim 11, wherein, Further comprising: A differential phase reliability estimator configured to determine a differential phase reliability e(t-N+1) according to the modulation result y(t-N+1) of the past N-1 periods, the actual differential phase w(t-N+1) and the signal phase v(t-N+1); The differential phase equalizer is configured to equalize the differential phase p(t-1), p(t-2), …, p(t-N+1) of the past N-1 periods according to the differential phase reliability e(t-1), e(t-2), …, e(t-N+1) to obtain the actual differential phase w(t).

14. A computer readable storage medium storing a program, when the program is executed by a multi-core processor, causes the multi-core processor to execute the method of any one of claims 1-10.

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