Digital pre-distortion processing method and system based on lookup table

Abstract

The invention discloses a digital pre-distortion processing method based on a lookup table. The method comprises the following steps: acquiring a first component and a second component of baseband input so as to obtain an original digital baseband signal amplitude value according to the first component and the second component; when judging that the amplitude value of the original digital baseband signal is greater than a first preset threshold value, determining a corresponding lookup table index according to the amplitude value of the original digital baseband signal to obtain a first component increment and a second component increment so as to carry out digital pre-distortion compensation; wherein the first component increment and the second component increment are determined through an AM-AM curve and an AM-PM curve, the AM-AM curve is used for determining the amplitude of the power amplifier to be mapped, and the AM-PM curve is used for determining the phase delay of the power amplifier to be mapped. The I component increment and the Q component increment can be accurately determined through the AM-AM curve and the AM-PM curve, so that the precision of digital pre-distortion compensation is improved. And the judgment on the DPD compensation effectiveness can prevent the compensated value from overflowing the bit width, so that the compensation accuracy is improved.

Description

Technical Field

[0001] The present invention belongs to the field of signal processing, and in particular relates to a digital predistortion processing method and system based on a lookup table. Background Art

[0002] In current non-constant envelope modulation communication systems, modulation techniques that utilize high-bandwidth bandwidths, such as orthogonal frequency division multiplexing (OFDM) and quadrature amplitude modulation (QAM), are the most widely used. These modulation techniques have been extensively researched and applied in recent years because they effectively improve channel communication capacity. While QAM and OFDM offer high spectrum efficiency, they also have inherent drawbacks. Because the signal envelopes of these modulation techniques vary over time, these signals exhibit high peak-to-average radio (PAR) ratios, significantly impacting the power amplifier (PA) at the RF end. When the modulated signal passes through the PA, intermodulation distortion (IMD) is generated due to the PA's inherent nonlinearity. This spectral regrowth caused by the PA's nonlinearity reduces the adjacent channel power ratio (ACPR), resulting in severe adjacent channel interference (ACI). Furthermore, in-band distortion significantly increases the receiver's bit error rate (BER), severely impacting signal transmission. To suppress spectral regrowth, the classic approach is to operate the power amplifier in its linear region, using power back-off technology. However, this results in a significant waste of amplifier resources, significantly reducing amplifier efficiency and increasing system costs. Driven by the need to improve amplifier efficiency while maintaining high linearity, power amplifier linearization technology has become a research hotspot both domestically and internationally.

[0003] Currently, there are two main popular digital baseband pre-distortion methods: the first is a polynomial-based digital baseband pre-distortion method, and the second is a lookup table-based pre-distortion method. The first method uses indirect learning to form the characteristic curve of the RF power amplifier and approximate the output of the actual power amplifier with a finite-order polynomial. After obtaining the approximate polynomial model of the power amplifier, a polynomial model with opposite characteristics is used at the front end to pre-distort the signal. The advantage of the polynomial method is its convenience. It is easy to implement for low-order approximation models and does not require additional memory. However, its disadvantage is also obvious: if the order is too low, the approximation accuracy is insufficient, while if the order is too high, the processing speed cannot keep up. The second method, using a lookup table, can improve processing efficiency to a certain extent. However, the currently common lookup table pre-distortion methods cannot strike a balance between distortion distribution, distortion size, and cost, resulting in low overall accuracy. Summary of the Invention

[0004] In order to solve the above problems existing in the prior art, the present invention provides a digital predistortion processing method and system based on a lookup table. The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0005] A digital predistortion processing method based on a lookup table, comprising:

[0006] Acquire a first component and a second component of a baseband input to obtain an original digital baseband signal amplitude value according to the first component and the second component;

[0007] When it is determined that the amplitude value of the original digital baseband signal is greater than a first preset threshold, determining a corresponding lookup table index according to the original digital baseband amplitude value to obtain a first component increment and a second component increment for digital predistortion compensation;

[0008] The first component increment and the second component increment are determined by an AM-AM curve and an AM-PM curve, the AM-AM curve is used to determine the amplitude of the power amplifier to be mapped, and the AM-PM curve is used to determine the phase delay of the power amplifier to be mapped.

[0009] In a specific embodiment, the first component increment is determined by the following formula:

[0010]

[0011] Wherein, Δi represents the increment of the first component, x2 represents the amplitude of the power amplifier to be mapped, x1 represents the amplitude value of the original digital baseband signal, and phi2 is the phase delay of the power amplifier to be mapped;

[0012] The second component increment is determined by the following formula:

[0013]

[0014] Wherein, Δq represents the second component increment, x2 represents the amplitude of the power amplifier to be mapped, x1 represents the amplitude value of the original digital baseband signal, and phi2 is the phase delay of the power amplifier to be mapped.

[0015] In a specific embodiment, the amplitude of the power amplifier to be mapped and the phase delay of the power amplifier to be mapped are obtained by interpolating and fitting the AM-AM curve and the AM-PM curve;

[0016] The formula for interpolation fitting of the amplitude of the power amplifier to be mapped is:

[0017]

[0018] Wherein, x2 represents the amplitude of the power amplifier to be mapped, y2 is the output amplitude, y2a and y2b are the output amplitude coordinate points adjacent to y2 on the AM-AM curve, and x2a and x2b are the input amplitude coordinate points adjacent to x2 on the AM-AM curve.

[0019] The formula for interpolating and fitting the phase delay of the power amplifier to be mapped is:

[0020]

[0021] Wherein, phi2 represents the phase delay of the power amplifier to be mapped, y2 is the output amplitude, y2a and y2b are the output amplitude coordinate points adjacent to y2 and on the AM-PM curve, and phi2a and phi2b are the phase delay coordinate points adjacent to phi2 and on the AM-PM curve.

[0022] In a specific embodiment, when it is determined that the amplitude value of the original digital baseband signal is less than or equal to a second preset threshold, digital pre-distortion compensation is performed; when it is determined that the amplitude value of the original digital baseband signal is greater than the second preset threshold, digital pre-distortion compensation is not performed; wherein, the first preset threshold is 1024 and the second preset threshold is 1440.

[0023] In a specific embodiment, when it is determined that the bit width of the compensated first component or the compensated second component exceeds a preset bit width, the compensated first component and the compensated second component are rolled back, wherein the preset bit width is 12 bits.

[0024] In a specific embodiment, a limit range of the digital baseband gain is preset so that the amplitude value of the original digital baseband signal does not exceed a second preset threshold.

[0025] The present invention also provides a digital predistortion processing system based on a lookup table, comprising:

[0026] a data input module, configured to obtain a first component and a second component of a baseband input to obtain an amplitude value of an original digital baseband signal according to the first component and the second component;

[0027] a predistortion compensation module, configured to, when determining that the amplitude value of the original digital baseband signal is greater than a first preset threshold, determine a corresponding lookup table index according to the original digital baseband amplitude value to obtain a first component increment and a second component increment for performing digital predistortion compensation;

[0028] The first component increment and the second component increment are determined by an AM-AM curve and an AM-PM curve, the AM-AM curve is used to determine the amplitude of the power amplifier to be mapped, and the AM-PM curve is used to determine the phase delay of the power amplifier to be mapped.

[0029] In a specific embodiment, the first component increment is determined by the following formula:

[0030]

[0031] Wherein, Δi represents the increment of the first component, x2 represents the amplitude of the power amplifier to be mapped, x1 represents the amplitude value of the original digital baseband signal, and phi2 is the phase delay of the power amplifier to be mapped;

[0032] The second component increment is determined by the following formula:

[0033]

[0034] Wherein, Δq represents the second component increment, x2 represents the amplitude of the power amplifier to be mapped, x1 represents the amplitude value of the original digital baseband signal, and phi2 is the phase delay of the power amplifier to be mapped.

[0035] In a specific embodiment, the amplitude of the power amplifier to be mapped and the phase delay of the power amplifier to be mapped are obtained by interpolating and fitting the AM-AM curve and the AM-PM curve;

[0036] The formula for interpolation fitting of the amplitude of the power amplifier to be mapped is:

[0037]

[0038] Wherein, x2 represents the amplitude of the power amplifier to be mapped, y2 is the output amplitude, y2a and y2b are the output amplitude coordinate points adjacent to y2 on the AM-AM curve, and x2a and x2b are the input amplitude coordinate points adjacent to x2 on the AM-AM curve.

[0039] The formula for interpolating and fitting the phase delay of the power amplifier to be mapped is:

[0040]

[0041] Wherein, phi2 represents the phase delay of the power amplifier to be mapped, y2 is the output amplitude, y2a and y2b are the output amplitude coordinate points adjacent to y2 and on the AM-PM curve, and phi2a and phi2b are the phase delay coordinate points adjacent to phi2 and on the AM-PM curve.

[0042] In a specific embodiment, when it is determined that the amplitude value of the original digital baseband signal is less than or equal to a second preset threshold, digital pre-distortion compensation is performed; when it is determined that the amplitude value of the original digital baseband signal is greater than the second preset threshold, digital pre-distortion compensation is not performed; wherein, the first preset threshold is 1024 and the second preset threshold is 1440.

[0043] In a specific embodiment, when it is determined that the bit width of the compensated first component or the compensated second component exceeds a preset bit width, the compensated first component and the compensated second component are rolled back, wherein the preset bit width is 12 bits.

[0044] Beneficial effects of the present invention:

[0045] A lookup table-based digital predistortion processing method according to the present invention includes: obtaining a first component and a second component of a baseband input to obtain an original digital baseband signal amplitude value based on the first and second components; when determining that the original digital baseband signal amplitude value is greater than a first preset threshold, determining a corresponding lookup table index based on the original digital baseband amplitude value to obtain a first component increment and a second component increment for digital predistortion compensation; wherein the first component increment and the second component increment are determined using an AM-AM curve and an AM-PM curve, the AM-AM curve being used to determine the amplitude of a power amplifier to be mapped, and the AM-PM curve being used to determine the phase delay of the power amplifier to be mapped. Thus, the AM-AM curve and the AM-PM curve can accurately determine the I component increment and the Q component increment, thereby improving the accuracy of digital predistortion compensation.

[0046] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is a flow chart of a digital predistortion processing method based on a lookup table provided by an embodiment of the present invention;

[0048] Figure 2 2 is a schematic diagram of interpolation calculation of x2 and phi2 provided in an embodiment of the present invention;

[0049] Figure 3a This is a schematic diagram of the I+1j*Q range where the original amplitude does not exceed 1024 and DPD compensation is not required, provided by an embodiment of the present invention;

[0050] Figure 3b This is a schematic diagram of the I+1j*Q range where the original amplitude exceeds 1024 but overflows the bit width after DPD compensation, provided by an embodiment of the present invention;

[0051] Figure 3cAn embodiment of the present invention provides an I+1j*Q range in which the original amplitude exceeds 1024 and does not overflow the bit width after DPD compensation.

[0052] Figure 4a Another embodiment of the present invention provides an I+1j*Q range where the original amplitude does not exceed 1024 and DPD compensation is not required.

[0053] Figure 4b Another embodiment of the present invention provides that the original amplitude exceeds 1024 but does not exceed 1440, and DPD compensation can be performed directly without overflowing the bit width I+1j*Q range;

[0054] Figure 5 This is a block diagram of a digital predistortion processing system module based on a lookup table provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0055] The present invention will be further described in detail below with reference to specific examples, but the embodiments of the present invention are not limited thereto.

[0056] Example 1

[0057] See Figure 1 , Figure 1 1 is a flow chart of a digital predistortion processing method based on a lookup table provided by an embodiment of the present invention, comprising:

[0058] Acquire a first component and a second component of a baseband input to obtain an original digital baseband signal amplitude value according to the first component and the second component;

[0059] In this embodiment, the first component is, for example, the i component, and the second component is, for example, the q component. The DPD uses a portion of the square value of the digital baseband signal amplitude as an index to search for the corresponding i and q increments, thereby calculating the compensated I and Q values and sending them to the DA. The lookup table storage structure is shown in Table 1.

[0060] Among them, the digital baseband signal amplitude is expressed as The square value of the digital baseband signal amplitude is represented by a; the square value of the digital baseband signal amplitude is right-shifted by 14 bits and represented by A as the search index.

[0061] Table 1 Digital predistortion lookup table storage structure

[0062]

[0063] When it is determined that the amplitude value of the original digital baseband signal is greater than a first preset threshold, determining a corresponding lookup table index according to the original digital baseband amplitude value to obtain a first component increment and a second component increment for digital predistortion compensation;

[0064] That is, when When the value is small (for example ), the transmission link works in the linear region, and the corresponding input i and q do not need to use DPD to obtain better transmission performance, so there is no need to look up the table; when When the value is large (for example ), the transmission link works in the nonlinear region, and the corresponding inputs i and q need to use DPD to obtain better transmission performance, so a table lookup is required.

[0065] In Table 1, A = a[22:14], a = q^2 + i^2, Δq represents the increment relative to q, and Δi represents the increment relative to i; based on this, it can be calculated that Q = Δi*q + i*Δq, and I = Δi*iq*Δq.

[0066] The first component increment and the second component increment are determined using an AM-AM curve and an AM-PM curve. The AM-AM curve is used to determine the amplitude of the power amplifier to be mapped, and the AM-PM curve is used to determine the phase delay of the power amplifier to be mapped. For example, the amplitude and phase delay of sine waves of different amplitudes after passing through the PA can be measured using two loops, RFLOOPB and BBLOOPB.

[0067] In a specific embodiment, the first component increment is determined by the following formula:

[0068]

[0069] Wherein, Δi represents the increment of the first component, x2 represents the amplitude of the power amplifier to be mapped, x1 represents the amplitude value of the original digital baseband signal, and phi2 is the phase delay of the power amplifier to be mapped.

[0070] In a specific embodiment, the second component increment is determined by the following formula:

[0071]

[0072] Wherein, Δq represents the second component increment, x2 represents the amplitude of the power amplifier to be mapped, x1 represents the amplitude value of the original digital baseband signal, and phi2 is the phase delay of the power amplifier to be mapped.

[0073] The specific derivation process is as follows:

[0074] The process of obtaining x2 from x1, that is, the input amplitude of DPD For example, it needs to be mapped to the PA input amplitude x2. At the same time, the PA phase delay phi2 at the mapped amplitude x2 needs to be supplemented. That is, for the DPD input data i+1j·q, it needs to be mapped to the PA input data

[0075] In one specific embodiment, the amplitude and phase delay of the power amplifier to be mapped are obtained by interpolating and fitting the AM-AM curve and the AM-PM curve. It should be noted that since the collected AM-AM data and AM-PM data are finite and discrete, the point (x2, y2) is likely not included in the existing AM-AM data, and the point (x2, phi2) is likely not included in the existing AM-PM data, so interpolation and fitting are required.

[0076] See Figure 2 , Figure 2 Schematic diagram of interpolation calculation of x2 and phi2. In a specific implementation manner, the formula for interpolation fitting of the amplitude of the power amplifier to be mapped is:

[0077]

[0078] Wherein, x2 represents the amplitude of the power amplifier to be mapped, and y2 is the output amplitude. In this embodiment, y2=x1·10 25 / 20 / 10, y2a and y2b are the output amplitude coordinate points adjacent to y2 and on the AM-AM curve, and x2a and x2b are the input amplitude coordinate points adjacent to x2 and on the AM-AM curve.

[0079] In a specific implementation, the formula for interpolating and fitting the phase delay of the power amplifier to be mapped is:

[0080]

[0081] Wherein, phi2 represents the phase delay of the power amplifier to be mapped, y2 is the output amplitude, y2a and y2b are the output amplitude coordinate points adjacent to y2 and on the AM-PM curve, and phi2a and phi2b are the phase delay coordinate points adjacent to phi2 and on the AM-PM curve.

[0082] In a specific implementation, when it is determined that the amplitude value of the original digital baseband signal is less than or equal to a second preset threshold, digital predistortion compensation is performed; when it is determined that the amplitude value of the original digital baseband signal is greater than the second preset threshold, digital predistortion compensation is not performed.

[0083] In a specific implementation, the first preset threshold is 1024, and the second preset threshold is 1440.

[0084] In an embodiment, for example, a limit range of the digital baseband gain can be pre-set so that the amplitude value of the original digital baseband signal does not exceed the second preset threshold value, thereby eliminating the need for the aforementioned judgment logic, thereby improving compensation efficiency. In addition, pre-setting the limit range of the digital baseband gain can enable the amplitude value of the original digital baseband signal to obtain uniform gain amplification after passing through DPD, thereby minimizing signal distortion.

[0085] In a specific embodiment, when it is determined that the bit width of the compensated first component or the compensated second component exceeds a preset bit width, the compensated first component and the compensated second component are rolled back. Preferably, the preset bit width is 12 bits.

[0086] Specifically, for DPD compensation, in one embodiment, since there is no limit on the amplitude after compensation, the maximum value can reach 2896. At this time, the problem of I+1j*Q overflowing the bit width after compensation may occur. Through Monte Carlo simulation, I and Q are both 12-bit numbers uniformly distributed in [-2047, +-2047]. 500,000 such I+1j*Q samples are randomly generated and classified according to the results after DPD compensation. Figure 3a Indicates the I+1j*Q range where the original amplitude does not exceed 1024 and DPD compensation is not required; Figure 3b Indicates that the original amplitude exceeds 1024 but overflows the bit width I+1j*Q range after DPD compensation; Figure 3c Indicates that the original amplitude exceeds 1024 and does not overflow the I+1j*Q range of the bit width after DPD compensation. This embodiment needs to identify Figure 3b In this case, the compensated I+1j*Q must be rolled back to restore the original I+1j*Q. This determination scheme requires determining whether the I and Q values after each DPD compensation overflow the bit width.

[0087] In another embodiment, DPD compensation is performed for I+1j*Q whose original amplitude does not exceed 2047 / 1.42118=1440, and DPD compensation is not performed for I+1j*Q whose original amplitude exceeds 2047 / 1.42118=1440. This parallel solution does not require the determination of whether the I and Q after DPD compensation overflow the bit width. Accordingly, Figure 4a Indicates the I+1j*Q range where the original amplitude does not exceed 1024 and DPD compensation is not required; Figure 4b This means that if the original amplitude exceeds 1024 but does not exceed 1440, DPD compensation can be performed directly without overflowing the bit width I+1j*Q range.

[0088] Therefore, by judging the effectiveness of DPD compensation, it is possible to avoid the compensated value from overflowing the bit width, thereby improving the compensation accuracy. In addition, for different usage scenarios, it is possible to determine whether to perform compensation or fallback by judging the original amplitude value before compensation or the bit width after compensation, which facilitates operation.

[0089] A lookup table-based digital predistortion processing method according to this embodiment includes: obtaining a first component and a second component of a baseband input to obtain an original digital baseband signal amplitude value based on the first component and the second component; when determining that the original digital baseband signal amplitude value is greater than a first preset threshold, determining a corresponding lookup table index based on the original digital baseband amplitude value to obtain a first component increment and a second component increment for digital predistortion compensation; wherein the first component increment and the second component increment are determined using an AM-AM curve and an AM-PM curve, the AM-AM curve being used to determine the amplitude of a power amplifier to be mapped, and the AM-PM curve being used to determine the phase delay of the power amplifier to be mapped. Thus, the AM-AM curve and the AM-PM curve can accurately determine the I component increment and the Q component increment, thereby improving the accuracy of digital predistortion compensation.

[0090] See Figure 5 , Figure 5 This is a block diagram of a digital predistortion processing system module based on a lookup table provided by an embodiment of the present invention, including:

[0091] a data input module, configured to obtain a first component and a second component of a baseband input to obtain an amplitude value of an original digital baseband signal according to the first component and the second component;

[0092] a predistortion compensation module, configured to, when determining that the amplitude value of the original digital baseband signal is greater than a first preset threshold, determine a corresponding lookup table index according to the original digital baseband amplitude value to obtain a first component increment and a second component increment for performing digital predistortion compensation;

[0093] The first component increment and the second component increment are determined by an AM-AM curve and an AM-PM curve, the AM-AM curve is used to determine the amplitude of the power amplifier to be mapped, and the AM-PM curve is used to determine the phase delay of the power amplifier to be mapped.

[0094] In a specific embodiment, the first component increment is determined by the following formula:

[0095]

[0096] Wherein, Δi represents the increment of the first component, x2 represents the amplitude of the power amplifier to be mapped, x1 represents the amplitude value of the original digital baseband signal, and phi2 is the phase delay of the power amplifier to be mapped;

[0097] The second component increment is determined by the following formula:

[0098]

[0099] Wherein, Δq represents the second component increment, x2 represents the amplitude of the power amplifier to be mapped, x1 represents the amplitude value of the original digital baseband signal, and phi2 is the phase delay of the power amplifier to be mapped.

[0100] In a specific embodiment, the amplitude of the power amplifier to be mapped and the phase delay of the power amplifier to be mapped are obtained by interpolating and fitting the AM-AM curve and the AM-PM curve;

[0101] The formula for interpolation fitting of the amplitude of the power amplifier to be mapped is:

[0102]

[0103] Wherein, x2 represents the amplitude of the power amplifier to be mapped, y2 is the output amplitude, y2a and y2b are the output amplitude coordinate points adjacent to y2 on the AM-AM curve, and x2a and x2b are the input amplitude coordinate points adjacent to x2 on the AM-AM curve.

[0104] The formula for interpolating and fitting the phase delay of the power amplifier to be mapped is:

[0105]

[0106] Wherein, phi2 represents the phase delay of the power amplifier to be mapped, y2 is the output amplitude, y2a and y2b are the output amplitude coordinate points adjacent to y2 and on the AM-PM curve, and phi2a and phi2b are the phase delay coordinate points adjacent to phi2 and on the AM-PM curve.

[0107] In a specific embodiment, when it is determined that the amplitude value of the original digital baseband signal is less than or equal to a second preset threshold, digital pre-distortion compensation is performed; when it is determined that the amplitude value of the original digital baseband signal is greater than the second preset threshold, digital pre-distortion compensation is not performed; wherein, the first preset threshold is 1024 and the second preset threshold is 1440.

[0108] In a specific embodiment, when it is determined that the bit width of the compensated first component or the compensated second component exceeds a preset bit width, the compensated first component and the compensated second component are rolled back, wherein the preset bit width is 12 bits.

[0109] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0110] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to 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, those skilled in the art can combine and combine different embodiments or examples described in this specification.

[0111] Although the present application is described herein in conjunction with various embodiments, in the process of implementing the claimed application, those skilled in the art can understand and implement other changes to the disclosed embodiments by reviewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple situations. A single processor or other unit can implement several functions listed in the claims. Certain measures are recorded in different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0112] The above is a further detailed description of the present invention in conjunction with specific preferred embodiments, and the specific implementation of the present invention should not be considered to be limited to these descriptions. For those skilled in the art of the present invention, without departing from the concept of the present invention, several simple deductions or substitutions can be made, which should be considered to fall within the scope of protection of the present invention.

Claims

1. A digital predistortion processing method based on a lookup table, characterized in that: include: Acquire a first component and a second component of a baseband input to obtain an original digital baseband signal amplitude value according to the first component and the second component; When it is determined that the amplitude value of the original digital baseband signal is greater than a first preset threshold, determining a corresponding lookup table index according to the original digital baseband amplitude value to obtain a first component increment and a second component increment for digital predistortion compensation; The first component increment and the second component increment are determined by an AM-AM curve and an AM-PM curve, the AM-AM curve is used to determine the amplitude of the power amplifier to be mapped, and the AM-PM curve is used to determine the phase delay of the power amplifier to be mapped.

2. The digital predistortion processing method based on a lookup table according to claim 1, characterized in that: The first component increment is determined by the following formula: Wherein, Δi represents the increment of the first component, x2 represents the amplitude of the power amplifier to be mapped, x1 represents the amplitude value of the original digital baseband signal, and phi2 is the phase delay of the power amplifier to be mapped; The second component increment is determined by the following formula: Wherein, Δq represents the second component increment, x2 represents the amplitude of the power amplifier to be mapped, x1 represents the amplitude value of the original digital baseband signal, and phi2 is the phase delay of the power amplifier to be mapped.

3. The digital predistortion processing method based on a lookup table according to claim 1, characterized in that: The amplitude of the power amplifier to be mapped and the phase delay of the power amplifier to be mapped are obtained by interpolating and fitting the AM-AM curve and the AM-PM curve; The formula for interpolation fitting of the amplitude of the power amplifier to be mapped is: Wherein, x2 represents the amplitude of the power amplifier to be mapped, y2 is the output amplitude, y2a and y2b are the output amplitude coordinate points adjacent to y2 on the AM-AM curve, and x2a and x2b are the input amplitude coordinate points adjacent to x2 on the AM-AM curve. The formula for interpolating and fitting the phase delay of the power amplifier to be mapped is: Wherein, phi2 represents the phase delay of the power amplifier to be mapped, y2 is the output amplitude, y2a and y2b are the output amplitude coordinate points adjacent to y2 and on the AM-PM curve, and phi2a and phi2b are the phase delay coordinate points adjacent to phi2 and on the AM-PM curve.

4. The digital predistortion processing method based on a lookup table according to claim 1, characterized in that: When it is determined that the amplitude value of the original digital baseband signal is less than or equal to a second preset threshold, digital predistortion compensation is performed; when it is determined that the amplitude value of the original digital baseband signal is greater than the second preset threshold, digital predistortion compensation is not performed; wherein the first preset threshold is 1024 and the second preset threshold is 1440.

5. The digital predistortion processing method based on a lookup table according to claim 1, characterized in that: When it is determined that the bit width of the compensated first component or the compensated second component exceeds a preset bit width, the compensated first component and the compensated second component are rolled back, wherein the preset bit width is 12 bits.

6. The digital predistortion processing method based on a lookup table according to claim 1, characterized in that: The limit range of the digital baseband gain is preset so that the amplitude value of the original digital baseband signal does not exceed the second preset threshold.

7. A digital predistortion processing system based on a lookup table, characterized in that: include: a data input module, configured to obtain a first component and a second component of a baseband input to obtain an amplitude value of an original digital baseband signal according to the first component and the second component; a predistortion compensation module, configured to, when determining that the amplitude value of the original digital baseband signal is greater than a first preset threshold, determine a corresponding lookup table index according to the original digital baseband amplitude value to obtain a first component increment and a second component increment for performing digital predistortion compensation; The first component increment and the second component increment are determined by an AM-AM curve and an AM-PM curve, the AM-AM curve is used to determine the amplitude of the power amplifier to be mapped, and the AM-PM curve is used to determine the phase delay of the power amplifier to be mapped.

8. The digital predistortion processing system based on a lookup table according to claim 7, characterized in that: The first component increment is determined by the following formula: Wherein, Δi represents the increment of the first component, x2 represents the amplitude of the power amplifier to be mapped, x1 represents the amplitude value of the original digital baseband signal, and phi2 is the phase delay of the power amplifier to be mapped; The second component increment is determined by the following formula: Wherein, Δq represents the second component increment, x2 represents the amplitude of the power amplifier to be mapped, x1 represents the amplitude value of the original digital baseband signal, and phi2 is the phase delay of the power amplifier to be mapped.

9. The digital predistortion processing system based on a lookup table according to claim 7, characterized in that: The amplitude of the power amplifier to be mapped and the phase delay of the power amplifier to be mapped are obtained by interpolating and fitting the AM-AM curve and the AM-PM curve; The formula for interpolation fitting of the amplitude of the power amplifier to be mapped is: Wherein, x2 represents the amplitude of the power amplifier to be mapped, y2 is the output amplitude, y2a and y2b are the output amplitude coordinate points adjacent to y2 on the AM-AM curve, and x2a and x2b are the input amplitude coordinate points adjacent to x2 on the AM-AM curve. The formula for interpolating and fitting the phase delay of the power amplifier to be mapped is: Wherein, phi2 represents the phase delay of the power amplifier to be mapped, y2 is the output amplitude, y2a and y2b are the output amplitude coordinate points adjacent to y2 and on the AM-PM curve, and phi2a and phi2b are the phase delay coordinate points adjacent to phi2 and on the AM-PM curve.

10. The digital predistortion processing system based on a lookup table according to claim 7, characterized in that: When it is determined that the amplitude value of the original digital baseband signal is less than or equal to a second preset threshold, digital predistortion compensation is performed; when it is determined that the amplitude value of the original digital baseband signal is greater than the second preset threshold, digital predistortion compensation is not performed; wherein the first preset threshold is 1024 and the second preset threshold is 1440.

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