Dual-mode wireless communication two-stage feedback type automatic gain control method and system

Abstract

The invention discloses a dual-mode wireless communication two-stage feedback type automatic gain control method and system, and the method comprises the steps: carrying out the amplitude adjustment and modulus adjustment of an analog baseband signal through an analog gain, obtaining a digital baseband signal, comparing the average power of the digital baseband signal with the target power of the analog gain, and calculating an analog gain coarse adjustment value; performing fine adjustment on the analog gain coarse adjustment value through the analog gain adjustment value increment factor, and calculating an analog gain fine adjustment value; performing amplitude adjustment on the analog baseband signal by using the analog gain value to realize first-stage feedback type analog automatic gain control; useful signal detection and abnormal point detection elimination processing are carried out on the digital baseband signal after analog gain amplitude adjustment; calculating the average power of the digital baseband signal after the abnormal points are eliminated according to the period, and calculating a digital gain adjustment value after the abnormal points are eliminated; and performing amplitude adjustment on the digital baseband signal based on the digital gain value to realize second-stage digital automatic gain control.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technology, and more particularly, to a two-mode wireless communication two-stage feedback automatic gain control method and system. Background Art

[0002] As an essential function in a communication system, automatic gain control has been widely applied in receivers of communication systems such as optical fiber communication, satellite communication, and radar communication. Automatic gain control is used to accurately control the amplitude of the input signal of the receiver when the received signal power varies within a large range, and to ensure that the output signal amplitude remains stable by adjusting the gain, thereby increasing the dynamic range of the receiver. That is, when a weak signal is input, the receiver increases the gain through automatic gain control to amplify the received signal; when the input signal reaches a certain intensity, the receiver controls the gain to decrease, so as to reduce the amplitude of the output signal and avoid amplitude saturation.

[0003] Traditional automatic gain control methods mainly adopt a feed-forward structure. The automatic gain control loop is located in an analog radio frequency receiver, and the analog gain of a variable gain amplifier is controlled and adjusted by the analog loop. Although the loop structure of the feed-forward automatic gain control method is simple, it has high requirements for hardware design and a slow gain adjustment speed. In addition, the gain control signal generated by the analog loop will introduce noise, resulting in jitter of the analog gain and affecting the stability of the output signal. Summary of the Invention

[0004] According to the present invention, there is provided a two-mode wireless communication two-stage feedback automatic gain control method and system to solve the technical problems that traditional automatic gain control methods mainly adopt a feed-forward structure, the automatic gain control loop is located in an analog radio frequency receiver, and the analog gain of a variable gain amplifier is controlled and adjusted by the analog loop. Although the loop structure of the feed-forward automatic gain control method is simple, it has high requirements for hardware design and a slow gain adjustment speed. In addition, the gain control signal generated by the analog loop will introduce noise, resulting in jitter of the analog gain and affecting the stability of the output signal.

[0005] According to the first aspect of the present invention, there is provided a two-mode wireless communication two-stage feedback automatic gain control method, including:

[0006] Receiving a radio frequency signal and performing frequency conversion to obtain an analog baseband signal, adjusting the amplitude of the analog baseband signal through analog gain and performing analog-to-digital conversion to obtain a digital baseband signal, calculating the average power of the digital baseband signal according to a period, comparing the average power with the analog gain target power, and calculating a rough analog gain adjustment value;

[0007] Evaluate the amplitude saturation degree of the digital baseband signal based on the average power of the digital baseband signal. According to the amplitude saturation degree of the digital baseband signal, finely adjust the rough adjustment value of the analog gain through the analog gain adjustment value increment factor, and calculate the fine adjustment value of the analog gain;

[0008] Feed back the fine adjustment value of the analog gain to the analog radio frequency receiver. The analog radio frequency receiver adjusts the analog gain of the down-converted analog baseband signal periodically based on the fine adjustment value of the analog gain, and uses the analog gain value to adjust the amplitude of the analog baseband signal to obtain the analog baseband signal after analog gain adjustment amplitude, realizing the first-level feedback analog automatic gain control;

[0009] Perform useful signal detection and abnormal point detection and elimination processing on the digital baseband signal after analog gain adjustment amplitude to obtain the digital baseband signal sampling points after abnormal point elimination;

[0010] According to the digital baseband signal sampling points after abnormal point elimination, calculate the average power of the digital baseband signal after abnormal point elimination periodically, and calculate the digital gain adjustment value after abnormal point elimination based on the average power and the digital gain target power;

[0011] Adjust the digital gain of the digital baseband signal after abnormal point elimination periodically, and adjust the amplitude of the digital baseband signal based on the digital gain value to realize the second-level digital automatic gain control.

[0012] Optionally, receive the radio frequency signal, perform frequency conversion to obtain the analog baseband signal, pass the analog baseband signal through analog gain adjustment amplitude and analog-to-digital conversion to obtain the digital baseband signal, calculate the average power of the digital baseband signal periodically, compare the average power with the analog gain target power, and calculate the rough adjustment value of the analog gain, including:

[0013] Assume that the analog baseband signal is r(t), and the analog baseband signal after analog gain adjustment amplitude is The digital baseband signal is y(k), then the analog baseband signal r n (t) within the analog gain adjustment cycle time is expressed as:

[0014] r n (t) = r(t + nT A ), 0 ≤ t < T A , n = 0, 1, 2, …, N A -1

[0015] Among them, T A is the analog gain adjustment cycle time, and N A is the number of analog gain adjustment cycles. Then the digital baseband signal within the analog gain adjustment cycle length is expressed as:

[0016]

[0017] Among them, W A = F s ·T A is the length of the analog gain adjustment period, and F s is the sampling rate. Then The average power is expressed as:

[0018]

[0019] Among them, L A is the length of the analog gain calculation window, and L A < W A , |·| is the modulus of a complex number. By comparing the average power with the analog gain target power calculate the rough analog gain adjustment value which is expressed as:

[0020]

[0021] Optionally, based on the average power of the digital baseband signal, evaluate the amplitude saturation degree of the digital baseband signal, including:

[0022] Assume that the three-level power saturation thresholds are P1, P2, and P3 respectively, and satisfy the condition

[0023] When the average power A within the analog gain adjustment period length W is greater than the analog gain target power that is the rough analog gain adjustment value At this time, by comparing with P1, P2, and P3, judge the amplitude saturation degree of the digital baseband signal y(k):

[0024] If is greater than or equal to P1, that is then it is determined that the amplitude saturation degree of y(k) is high;

[0025] If is greater than or equal to P2 and less than P1, that is then it is determined that the amplitude saturation degree of y(k) is medium;

[0026] If is greater than or equal to P3 and less than P2, that is then it is determined that the amplitude saturation degree of y(k) is low;

[0027] If is less than P3, that is It is determined that the amplitude of y(k) is not saturated;

[0028] When the length W of the analog gain adjustment period A The average power within Is less than or equal to the analog gain target power That is At this time, the analog gain coarse adjustment value At this time, no comparison is made With the magnitudes of P1, P2, and P3, it is determined that the amplitude of the digital baseband signal y(k) is not saturated.

[0029] Optionally, based on the average power of the digital baseband signal, evaluate the amplitude saturation degree of the digital baseband signal. According to the amplitude saturation degree of the digital baseband signal, fine-tune the analog gain coarse adjustment value through the analog gain adjustment value increment factor, and calculate the analog gain fine adjustment value, including:

[0030] Assume that the analog gain adjustment value increment factors are G1, G2, and G3, and satisfy the condition G1 > G2 > G3 > 0. According to the amplitude saturation degree of the digital baseband signal y(k), calculate the length W of the analog gain adjustment period A The analog gain fine adjustment value within

[0031] If the amplitude saturation degree of the digital baseband signal y(k) is high, then use the analog gain adjustment value increment factor G1 to Fine-tune the analog gain coarse adjustment value and calculate the analog gain fine adjustment value Expressed as:

[0032]

[0033] If the amplitude saturation degree of the digital baseband signal y(k) is medium, then use the analog gain adjustment value increment factor G2 to Fine-tune the analog gain coarse adjustment value and calculate the analog gain fine adjustment value Expressed as:

[0034]

[0035] If the amplitude saturation degree of the digital baseband signal y(k) is low, then use the analog gain adjustment value increment factor G3 to Fine-tune the analog gain coarse adjustment value and calculate the analog gain fine adjustment value Expressed as:

[0036]

[0037] If the amplitude of the digital baseband signal y(k) is not saturated, then do not Fine-tune the analog gain coarse adjustment value, and the analog gain fine adjustment value Expressed as:

[0038]

[0039] Optionally, the analog gain fine-tuning value is fed back to the analog RF receiver, and the analog RF receiver adjusts the analog gain of the down-converted analog baseband signal periodically based on the analog gain fine-tuning value, and uses the analog gain value to adjust the amplitude of the analog baseband signal to obtain the analog baseband signal after the analog gain adjustment amplitude, realizing the first-stage feedback analog automatic gain control, including:

[0040] The amplitude adjustment process includes an analog gain adjustment stage and an analog gain locking stage. Within the analog gain adjustment cycle length W A the analog gain is adjusted with the analog gain fine-tuning value and the analog gain value is calculated and expressed as:

[0041]

[0042] where is the initial analog gain value. In the analog gain adjustment stage, the analog baseband signal r A within the analog gain adjustment cycle length W is amplitude-adjusted with the analog gain value A calculated within the analog gain adjustment cycle time T n (t). In the analog gain locking stage, the analog gain value is locked to the analog gain value A calculated within the last analog gain adjustment cycle length W to amplitude-adjust the analog baseband signal r(t), N A T A ≤t<T to obtain the analog baseband signal after the analog gain adjustment amplitude expressed as:

[0043]

[0044] where T is the duration of the analog baseband signal, T≥N A T A ;

[0045] Optionally, the useful signal detection and abnormal point detection and elimination processing are performed on the digital baseband signal after the analog gain adjustment amplitude, including:

[0046] The useful signal is detected by comparing the average power change of the digital baseband signal within two consecutive digital gain adjustment cycles after the analog gain adjustment amplitude, and the average power of the digital baseband signal is calculated according to the digital gain adjustment cycle. The digital baseband signal within the digital gain adjustment cycle length Expressed as:

[0047]

[0048] Wherein, W D is the digital gain adjustment period length, and N D is the number of digital gain adjustment periods, then The average power of is expressed as:

[0049]

[0050] Wherein, L D is the digital gain calculation window length, and L D < W D ;

[0051] Useful signal detection is performed by comparing the average power change of the digital baseband signal within two consecutive digital gain adjustment periods, including:

[0052] (1) Calculate the ratio R D of the average power and of the digital baseband signal within two consecutive digital gain adjustment periods of length W n , expressed as:

[0053]

[0054] (2) Compare the ratio R with and the useful signal detection threshold R: n a) If R

[0055] is greater than or equal to R, i.e., R n ≥ R, then it is determined that a useful signal is detected, and the useful signal detection ends; n b) If R

[0056] is less than R, i.e., R n < R, then it is determined that no useful signal is detected, n = n + 1. If n ≤ N n - 1, then return to step (1) to restart the useful signal detection; if n > N D - 1, end the useful signal detection. D Optionally, useful signal detection and abnormal point detection and elimination processing are performed on the digital baseband signal after the analog gain adjustment amplitude to obtain the sampled points of the digital baseband signal after elimination, including:

[0057]

[0058] ​During the digital gain adjustment period when a useful signal is detected, anomaly detection and elimination processing are performed by comparing the power of the sampling points and the average power. Assume that the useful signal is detected in the i-th (i = 1, 2, …, N D -1) digital gain adjustment period, then the length W of the i-th digital gain adjustment period D of the digital baseband signal average power is expressed as:

[0059]

[0060] During the digital gain adjustment period when a useful signal is detected, anomaly detection and elimination processing are performed by comparing the power of the sampling points and the average power. Specifically, it includes:

[0061] (1) Within the length W of the i-th digital gain adjustment period D , calculate the power P of the sampling points of the digital baseband signal , expressed as: m

[0062]

[0063] (2) Calculate the ratio I of the sampling point power P m and the average power , expressed as: m

[0064]

[0065] (3) Compare the ratio I of the sampling point power P m and the average power m with the anomaly detection threshold I:

[0066] a) If I m is greater than or equal to I, that is, I m ≥I, then it is determined that the sampling point of the digital baseband signal is an anomaly point, and the anomaly point elimination factor K is used to perform anomaly point elimination processing on to obtain the sampling point of the digital baseband signal after elimination , expressed as:

[0067]

[0068] b) If I m is less than I, that is, I m <I, then it is determined that the sampling point of the digital baseband signal m is a normal point, and no processing is performed on​​​​ Perform outlier elimination processing.

[0069] Optionally, according to the sampling points of the digital baseband signal after outlier elimination, calculate the average power of the digital baseband signal after outlier elimination in cycles, and calculate the digital gain adjustment value after outlier elimination based on the average power and the digital gain target power, including:

[0070] Calculate the average power of the digital baseband signal after outlier elimination and the digital gain adjustment value in the digital gain adjustment cycle. Within the digital gain adjustment cycle length W D Calculate the average power of the digital baseband signal after outlier elimination Expressed as:

[0071]

[0072] Based on the average power And the digital gain target power Calculate the digital gain adjustment value Expressed as:

[0073]

[0074] Optionally, adjust the digital gain of the digital baseband signal after outlier elimination in cycles, and perform amplitude adjustment on the digital baseband signal based on the digital gain value to achieve the second-level digital automatic gain control, including:

[0075] The amplitude adjustment process includes a digital gain adjustment stage and a digital gain locking stage. Within the digital gain adjustment cycle length W D Adjust the digital gain with the digital gain adjustment value To obtain the digital gain value Expressed as:

[0076]

[0077] In the digital gain adjustment stage, use the digital gain value To perform amplitude adjustment on the digital baseband signal In the digital gain locking stage, lock the digital gain value to the digital gain value calculated within the last digital gain adjustment cycle length W D Perform amplitude adjustment on the digital baseband signal y(k), k = N W D W D , N D W D + 1, …, F s ·T - 1 to perform amplitude adjustment to obtain the digital baseband signal after digital gain adjustment amplitude Expressed as:

[0078]

[0079] According to another aspect of the present invention, there is also provided a two-mode wireless communication two-stage feedback automatic gain control system, comprising:

[0080] A module for calculating the coarse adjustment value of the analog gain, configured to receive a radio frequency signal, perform frequency conversion to obtain an analog baseband signal, obtain a digital baseband signal by adjusting the amplitude and performing analog-to-digital conversion on the analog baseband signal, calculate the average power of the digital baseband signal periodically, compare the average power with the analog gain target power, and calculate the coarse adjustment value of the analog gain;

[0081] A module for calculating the fine adjustment value of the analog gain, configured to evaluate the amplitude saturation degree of the digital baseband signal based on the average power of the digital baseband signal, and according to the amplitude saturation degree of the digital baseband signal, finely adjust the coarse adjustment value of the analog gain through an analog gain adjustment value increment factor, and calculate the fine adjustment value of the analog gain;

[0082] The first feedback automatic gain control module is configured to feedback the fine adjustment value of the analog gain to the analog radio frequency receiver. The analog radio frequency receiver adjusts the analog gain of the down-converted analog baseband signal periodically based on the fine adjustment value of the analog gain, and uses the analog gain value to adjust the amplitude of the analog baseband signal to obtain the analog baseband signal after the analog gain adjustment amplitude, so as to implement the first-stage feedback analog automatic gain control;

[0083] A module for detecting the digital baseband signal is configured to perform useful signal detection and abnormal point detection and elimination processing on the digital baseband signal after the analog gain adjustment amplitude, and obtain the digital baseband signal sampling points after the abnormal points are eliminated;

[0084] A module for calculating the digital gain adjustment value is configured to calculate the average power of the digital baseband signal after the abnormal points are eliminated periodically according to the digital baseband signal sampling points after the abnormal points are eliminated, and calculate the digital gain adjustment value of the digital baseband signal after the abnormal points are eliminated based on the average power and the digital gain target power;

[0085] The second feedback automatic gain control module is configured to adjust the digital gain of the digital baseband signal after the abnormal points are eliminated periodically, and adjust the amplitude of the digital baseband signal based on the digital gain value to implement the second-stage digital automatic gain control.

[0086] Thus, the automatic gain control loop is placed between the analog radio frequency receiver and the digital baseband receiver. The analog radio frequency receiver uses a digital circuit to calculate the feedback gain control codeword and controls and adjusts the variable gain amplifier to implement automatic gain control, which can effectively reduce the hardware design requirements, improve the stability of the output signal, and save the receiver cost.

[0087] Under the premise of meeting the requirements of low power consumption and low latency and without increasing the circuit complexity, the present invention designs a two-stage automatic gain control method. The first stage is an analog automatic gain control with a feedback structure to accelerate the convergence speed of analog gain adjustment. The second stage is a digital automatic gain control introduced to improve the stability of the digital baseband signal amplitude and the accuracy of system frame synchronization, and to minimize the receiver cost, which is of great significance for improving the receiving performance of wireless communication systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0088] The exemplary embodiments of the present invention can be more fully understood by referring to the following drawings:

[0089] Figure 1 It is a schematic diagram of a two-mode wireless communication two-stage feedback automatic gain control method described in this embodiment;

[0090] Figure 2 It is a schematic diagram of the two-stage feedback automatic gain control method described in this embodiment;

[0091] Figure 3 It is a schematic diagram of the calculation flow of the two-stage feedback automatic gain control method described in this embodiment;

[0092] Figure 4 It is a schematic diagram of a two-mode wireless communication two-stage feedback automatic gain control system described in this embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0093] Now, the exemplary embodiments of the present invention will be introduced with reference to the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely, and to fully convey the scope of the present invention to those skilled in the art. The terms in the exemplary embodiments shown in the drawings are not intended to limit the present invention. In the drawings, the same units / components are denoted by the same reference numerals.

[0094] Unless otherwise specified, the terms (including scientific and technical terms) used herein have the ordinary meaning understood by those skilled in the art. In addition, it can be understood that the terms defined in the commonly used dictionary should be understood to have a meaning consistent with the context of their related fields, and should not be understood as idealized or overly formal meanings.

[0095] According to the first aspect of the present invention, a two-mode wireless communication two-stage feedback automatic gain control method 100 is provided. Referring to Figure 1 as shown, the method 100 includes:

[0096] S101: Receive a radio frequency signal, perform frequency conversion to obtain an analog baseband signal, adjust the amplitude of the analog baseband signal through analog gain and perform analog-to-digital conversion to obtain a digital baseband signal, calculate the average power of the digital baseband signal at intervals, compare the average power with the analog gain target power, and calculate the rough analog gain adjustment value;

[0097] S102: Based on the average power of the digital baseband signal, evaluate the amplitude saturation degree of the digital baseband signal. According to the amplitude saturation degree of the digital baseband signal, fine-tune the rough analog gain adjustment value through the analog gain adjustment value increment factor, and calculate the fine analog gain adjustment value;

[0098] S103: Feed back the fine analog gain adjustment value to the analog radio frequency receiver. The analog radio frequency receiver adjusts the analog gain of the down-converted analog baseband signal at intervals based on the fine analog gain adjustment value, and uses the analog gain value to adjust the amplitude of the analog baseband signal to obtain an analog baseband signal with adjusted amplitude through analog gain, thereby realizing the first-stage feedback analog automatic gain control;

[0099] S104: Perform useful signal detection and abnormal point detection and elimination processing on the digital baseband signal with adjusted amplitude through analog gain to obtain the sampled points of the digital baseband signal after abnormal point elimination;

[0100] S105: According to the sampled points of the digital baseband signal after abnormal point elimination, calculate the average power of the digital baseband signal after abnormal point elimination at intervals. Based on the average power and the digital gain target power, calculate the digital gain adjustment value after abnormal point elimination;

[0101] S106: Adjust the digital gain of the digital baseband signal after abnormal point elimination at intervals, and adjust the amplitude of the digital baseband signal based on the digital gain value to realize the second-stage digital automatic gain control.

[0102] Specifically, for the two-stage feedback automatic gain control method of the present invention, its overall process is as Figure 2 shown.

[0103] Step 1: The digital baseband receiver receives the digital baseband signal, calculates the average power of the digital baseband signal at intervals, compares the average power with the analog gain target power, and calculates the rough analog gain adjustment value. The digital baseband signal is obtained by adjusting the amplitude of the analog baseband signal through analog gain and performing analog-to-digital conversion. The analog baseband signal is obtained by down-converting the radio frequency signal received by the antenna. Calculate the average power of the digital baseband signal and the rough analog gain adjustment value at intervals according to the analog gain adjustment period. Assume the analog baseband signal is r(t), and the analog baseband signal after adjusting the amplitude through analog gain is The digital baseband signal is y(k), then the analog baseband signal r n (t) within the analog gain adjustment period is expressed as:

[0104] r n r(t) = r(t + nT A ), 0 ≤ t < T A , n = 0, 1, 2, …, N A -1

[0105] wherein, T A is the analog gain adjustment cycle time, and N A is the number of analog gain adjustment cycles. Then, the digital baseband signal within the analog gain adjustment cycle length is expressed as:

[0106]

[0107] wherein, W A = F s ·T A is the analog gain adjustment cycle length, and F s is the sampling rate. Then the average power of is expressed as:

[0108]

[0109] wherein, L A is the analog gain calculation window length, L A < W A , |·| is the modulus of a complex number. Comparing the average power with the analog gain target power to calculate the coarse adjustment value of the analog gain is expressed as:

[0110]

[0111] Step 2: Fine-tune the coarse adjustment value of the analog gain according to the amplitude saturation degree of the digital baseband signal, and calculate the fine adjustment value of the analog gain. The amplitude saturation degree of the digital baseband signal is determined by the magnitude relationship between the average power within the analog gain adjustment cycle length and the power saturation threshold, and the power saturation threshold includes three levels of power saturation thresholds. The following method is used to evaluate the amplitude saturation degree of the digital baseband signal, including the following steps:

[0112] Assume that the three-level power saturation thresholds are P1, P2, and P3, and satisfy the condition

[0113] (1) When the average power A within the analog gain adjustment cycle length W is greater than the analog gain target power i.e., then, the coarse adjustment value of the analog gain At this time, by comparing with P1, P2, and P3, the amplitude saturation degree of the digital baseband signal y(k) is judged:

[0114] a) If is greater than or equal to P1, that is then it is determined that the amplitude saturation degree of y(k) is high;

[0115] b) If is greater than or equal to P2 and less than P1, that is then it is determined that the amplitude saturation degree of y(k) is medium;

[0116] c) If is greater than or equal to P3 and less than P2, that is then it is determined that the amplitude saturation degree of y(k) is low;

[0117] d) If is less than P3, that is then it is determined that the amplitude of y(k) is not saturated.

[0118] (2) When the average power A within the analog gain adjustment period length W is less than or equal to the analog gain target power that is at this time, the analog gain coarse adjustment value At this time, it is not compared with P1, P2, and P3, and it is determined that the amplitude of the digital baseband signal y(k) is not saturated.

[0119] According to the amplitude saturation degree of the digital baseband signal, the analog gain coarse adjustment value is finely adjusted by using the analog gain adjustment value increment factor, and the analog gain fine adjustment value is calculated to accelerate the convergence speed of the analog gain adjustment. Assume that the analog gain adjustment value increment factors are G1, G2, and G3, and satisfy the condition G1 > G2 > G3 > 0. According to the amplitude saturation degree of the digital baseband signal y(k), calculate the analog gain fine adjustment value A within the analog gain adjustment period length W

[0120] a) If the amplitude saturation degree of the digital baseband signal y(k) is high, then the analog gain coarse adjustment value is finely adjusted by using the analog gain adjustment value increment factor G1, and the analog gain fine adjustment value is expressed as:

[0121]

[0122] b) If the amplitude saturation degree of the digital baseband signal y(k) is medium, then the analog gain coarse adjustment value Fine-tuning, calculating the fine-tuning value of the analog gain It is expressed as:

[0123]

[0124] c) If the amplitude saturation degree of the digital baseband signal y(k) is low, then use the analog gain adjustment value increment factor G3 to fine-tune the rough analog gain adjustment value Fine-tuning, calculating the fine-tuning value of the analog gain It is expressed as:

[0125]

[0126] d) If the amplitude of the digital baseband signal y(k) is not saturated, then do not fine-tune the rough analog gain adjustment value Fine-tuning, the fine-tuning value of the analog gain It is expressed as:

[0127]

[0128] Step 3: Feed back the fine-tuning value of the analog gain to the analog RF receiver, adjust the analog gain of the down-converted analog baseband signal periodically, and use the analog gain value to adjust the amplitude of the analog baseband signal to achieve the first-stage feedback analog automatic gain control. The digital baseband receiver feeds back the fine-tuning value of the analog gain to the analog RF receiver, and the analog RF receiver uses the fine-tuning value of the analog gain to adjust the analog gain of the analog baseband signal according to the analog gain adjustment period. The amplitude adjustment process includes an analog gain adjustment stage and an analog gain locking stage. Within the analog gain adjustment cycle length W A Use the fine-tuning value of the analog gain To adjust the analog gain, calculate the analog gain value It is expressed as:

[0129]

[0130] Where, Is the initial analog gain value. In the analog gain adjustment stage, use the analog gain value A Calculated within to adjust the amplitude of the analog baseband signal r Within the analog gain adjustment cycle time T A (t). In the analog gain locking stage, lock the analog gain value as the analog gain value n Calculated within the last analog gain adjustment cycle length W A To adjust the amplitude of the analog baseband signal r(t), N T A T A ≤t<T to adjust the amplitude, and obtain the analog baseband signal after the analog gain adjustment amplitude Expressed as:

[0131]

[0132] Wherein, T is the duration of the analog baseband signal, T≥N A T A .

[0133] Step 4: Perform useful signal detection and abnormal point detection and elimination processing on the digital baseband signal after the analog gain adjustment amplitude. The useful signal detection is achieved by comparing the average power change of the digital baseband signal within two consecutive digital gain adjustment periods after the analog gain adjustment amplitude. The abnormal point detection and elimination are processed within the digital gain adjustment period when the useful signal is detected. Calculate the average power of the digital baseband signal according to the digital gain adjustment period. The digital baseband signal within the digital gain adjustment period length Expressed as:

[0134]

[0135] Wherein, W D is the digital gain adjustment period length, and N D is the number of digital gain adjustment periods. Then The average power of Expressed as:

[0136]

[0137] Wherein, L D is the digital gain calculation window length, L D <W D . The following method is adopted to perform useful signal detection by comparing the average power change of the digital baseband signal within two consecutive digital gain adjustment periods, including the following steps:

[0138] (1) Calculate the ratio R D of the average power and of the digital baseband signal within two consecutive digital gain adjustment periods of length W n , expressed as:

[0139]

[0140] (2) Compare with for the ratio R n and the useful signal detection threshold R:

[0141] a) If R n is greater than or equal to R, that is, R nIf R ≥ R, it is determined that a useful signal is detected, and the detection of the useful signal ends.

[0142] b) If R n is less than R, that is, R n <R, it is determined that no useful signal is detected, and n = n + 1. If n ≤ N D - 1, return to step (1) to restart the detection of the useful signal; if n > N D - 1, end the detection of the useful signal.

[0143] During the digital gain adjustment period when a useful signal is detected, anomaly detection and elimination processing are performed by comparing the power of the sampling points and the average power, reducing the impact of anomalies on the system frame synchronization and improving the accuracy of frame synchronization. Assume that a useful signal is detected in the i-th (i = 1, 2,..., N D - 1) digital gain adjustment period, then the length W D of the i-th digital gain adjustment period and the digital baseband signal average power is expressed as:

[0144]

[0145] During the digital gain adjustment period when a useful signal is detected, the following method is used to perform anomaly detection and elimination processing by comparing the power of the sampling points and the average power, including the following steps:

[0146] (1) Within the length W D of the i-th digital gain adjustment period, calculate the power P of the sampling points of the digital baseband signal, expressed as: m

[0147]

[0148] (2) Calculate the ratio I m of the sampling point power P and the average power m , expressed as:

[0149]

[0150] (3) Compare the ratio I m of the sampling point power P and the average power m with the anomaly detection threshold I:

[0151] a) If I m is greater than or equal to I, that is, I m ≥ I, it is determined that the sampling points of the digital baseband signal ​ is an abnormal point. Using the abnormal point elimination factor K for carry out abnormal point elimination processing to obtain the sampled points of the digital baseband signal after elimination It is expressed as:

[0152]

[0153] b) If I m is less than I, that is, I m <I, then it is determined that the sampled points of the digital baseband signal are normal points and no abnormal point elimination processing is carried out.

[0154] Step Five, calculate the average power of the digital baseband signal after abnormal point elimination according to the period, compare the average power with the digital gain target power, and calculate the digital gain adjustment value. Calculate the average power of the digital baseband signal after abnormal point elimination and the digital gain adjustment value according to the digital gain adjustment period. Within the digital gain adjustment period length W D calculate the average power of the digital baseband signal after abnormal point elimination It is expressed as:

[0155]

[0156] Compare the average power with the digital gain target power calculate the digital gain adjustment value It is expressed as:

[0157]

[0158] Step Six, adjust the digital gain of the digital baseband signal after abnormal point elimination according to the period, use the digital gain value to adjust the amplitude of the digital baseband signal, and realize the second-level digital automatic gain control. The digital baseband receiver adjusts the digital gain of the digital baseband signal according to the digital gain adjustment value according to the digital gain adjustment period to improve the stability of the amplitude of the digital baseband signal. The amplitude adjustment process includes a digital gain adjustment stage and a digital gain locking stage. Within the digital gain adjustment period length W D adjust the digital gain with the digital gain adjustment value to obtain the digital gain value It is expressed as:

[0159]

[0160] In the digital gain adjustment stage, use the digital gain value to adjust the digital baseband signal Perform amplitude adjustment. During the digital gain locking phase, lock the digital gain value to the digital gain value calculated within the length W of the last digital gain adjustment period. D The digital gain value calculated within For the digital baseband signal y(k), k = N D W D , N D W D +1, …, F s ·T - 1 to perform amplitude adjustment, and obtain the digital baseband signal after digital gain adjustment amplitude. It is expressed as:

[0161]

[0162] So far, two - stage feedback automatic gain control has been realized. For a wireless communication system, the automatic gain control method of the present invention is simple to implement, has low circuit complexity, can accelerate the convergence speed of analog gain adjustment on the basis of meeting the requirements of low power consumption and low latency, improve the stability of the amplitude of the digital baseband signal and the accuracy of frame synchronization of the digital baseband receiver, and effectively save the cost of the receiver.

[0163] The technical solution provided by the present invention uses a feedback structure to implement the first - stage analog automatic gain control. Since the gain control signal generated by the traditional feed - forward automatic gain control loop will introduce noise when controlling the variable gain amplifier, resulting in jitter of the analog gain. Therefore, the automatic gain control method using a feedback structure places the automatic gain control loop between the analog RF receiver and the digital baseband receiver. The gain control circuit in the digital baseband receiver calculates the analog gain adjustment value, maps the analog gain adjustment value to discrete analog gain control codewords and feeds them back to the analog RF receiver, and realizes accurate analog gain adjustment by configuring the parameters of the variable gain amplifier.

[0164] In step two of this embodiment, the analog gain coarse adjustment value is finely adjusted according to the amplitude saturation degree of the digital baseband signal, and the analog gain fine adjustment value is calculated. Since there are limitations in calculating the analog gain adjustment value in digital circuits, when the analog baseband signal is very strong, the digital baseband signal after analog - to - digital conversion will have clipping distortion (amplitude saturation). The average power of the digital baseband signal after clipping distortion is lower than the average power of the analog baseband signal, resulting in a smaller calculated analog gain adjustment value and a longer analog gain locking time. Therefore, by evaluating the amplitude saturation degree of the digital baseband signal, the analog gain coarse adjustment value is finely adjusted to improve the convergence speed of analog gain adjustment.

[0165] In step three of this embodiment, the analog gain fine adjustment value is fed back to the analog RF receiver, and the analog gain of the down-converted analog baseband signal is adjusted periodically. The analog baseband signal is amplitude-adjusted using the analog gain value to achieve the first-stage feedback analog automatic gain control. Since there is a response delay in the feedback loop of the feedback automatic gain control, the analog gain fine adjustment value calculated within the current digital baseband signal analog gain adjustment period is used to adjust the analog gain of the next analog gain adjustment period. In addition, during the analog gain adjustment stage, the amplitude of the analog baseband signal changes as the analog gain adjustment converges; when the analog gain adjustment converges and stabilizes, the amplitude adjustment process enters the gain locking stage, and the analog gain is locked to the analog gain calculated in the last analog gain adjustment period, and the amplitude of the analog baseband signal remains stable and unchanged.

[0166] In step four of this embodiment, the useful signal detection and abnormal point detection and elimination processing are performed on the digital baseband signal after the amplitude adjustment by the analog gain. The digital baseband signal is amplitude-adjusted using the analog gain value and the digital gain value respectively. Since there will be a situation where the two adjustment periods are misaligned when the lengths of the analog gain adjustment period and the digital gain adjustment period are not equal, at this time, at the position where the average power of the digital baseband signal suddenly changes, that is, at the starting position of the useful signal, there may be abnormal points with strong power, resulting in system frame synchronization misalignment. Therefore, the useful signal detection and abnormal point detection and elimination processing are adopted to reduce the influence of the abnormal points on the frame synchronization and improve the system frame synchronization accuracy.

[0167] In step five of this embodiment, the average power of the digital baseband signal after the abnormal point elimination is calculated periodically, the average power is compared with the digital gain target power, and the digital gain adjustment value is calculated. Since there is a convergence process in the analog gain adjustment, when the input signal of the receiver is very strong, the analog RF receiver needs several analog gain adjustment periods to adjust the average power of the analog baseband signal to the analog gain target power by adjusting the analog gain, which will cause the amplitude of the digital baseband signal to jitter, thereby reducing the system frame synchronization performance. Therefore, the second-stage digital automatic gain control is introduced to improve the stability of the digital baseband signal amplitude and the system frame synchronization performance by utilizing the characteristic that the digital gain adjustment does not require convergence.

[0168] In step six of this embodiment, the digital gain of the digital baseband signal after the abnormal point elimination is adjusted periodically, and the digital baseband signal is amplitude-adjusted using the digital gain value to achieve the second-stage digital automatic gain control. Since the digital automatic gain control adopts a feed-forward structure and the digital gain adjustment has a fast response speed, the digital gain adjustment value calculated within the current digital baseband signal digital gain adjustment period is used to adjust the digital gain of the current digital gain adjustment period.

[0169] The following is combined with Figure 3, the method is applied to a specific example to illustrate the effectiveness of the method of the present invention. The method is applied to the wireless physical layer of the dual-mode communication protocol of the power user electricity consumption information acquisition system. The system architecture used refers to the wireless physical layer part of the "Dual-Mode Communication Interconnection Technology Specification Part 4-1: Physical Layer Communication Protocol" released by the State Grid. The communication mode used by the system is Option1, the radio frequency antenna communication frequency point is 471 MHz, the number of bits of the receiver analog-to-digital converter is 12 bits, and the sampling rate is F s = 2.083 MHz, and the length of the analog gain adjustment period is W A = 100, and the analog gain adjustment period time is T A = 0.048 μs, and the length of the analog gain calculation window is L A = 30, and the analog gain target power The saturation threshold P1 = 140629044, the saturation threshold P2 = 134692684, the saturation threshold P3 = 108608174, the analog gain adjustment value increment factor G1 = 9 dB, the analog gain adjustment value increment factor G2 = 6 dB, the analog gain adjustment value increment factor G3 = 3 dB, and the initial analog gain value The digital gain adjustment period length W D = 39, and the digital gain calculation window length L D = 30, the useful signal detection threshold R = 4, the abnormal point detection threshold I = 16, the abnormal point elimination factor K = 4, and the digital gain target power The duration of the analog baseband signal is T, the number of analog gain adjustment periods N A and the number of digital gain adjustment periods N A are determined by the locking times of the analog gain and the digital gain. The locking moments of the analog gain and the digital gain are the end moments of the system frame synchronization. The method mainly includes: calculating the rough adjustment value of the analog gain, calculating the fine adjustment value of the analog gain, adjusting the analog gain, detecting and eliminating the useful signal and the abnormal point, calculating the digital gain adjustment value, and adjusting the digital gain. The specific steps are as follows:

[0170] 1. Calculating the rough adjustment value of the analog gain

[0171] The digital baseband receiver receives the digital baseband signal y(k), divides the period of y(k) according to the length of the analog gain adjustment period W A to calculate the average power of the digital baseband signal within the nth (n = 0, 1,..., N A - 1) analog gain adjustment period Compare with the analog gain target power to calculate the rough adjustment value of the analog gain

[0172] ​2. Calculation of Analog Gain Fine Adjustment Value

[0173] Compare the average power of the digital baseband signal within the nth analog gain adjustment period with the power saturation thresholds P1, P2, and P3 to evaluate the amplitude saturation degree of y(k). According to the amplitude saturation degree of y(k), use the analog gain adjustment value increment factors G1, G2, and G3 to finely adjust the analog gain coarse adjustment value Calculate the analog gain fine adjustment value

[0174] 3. Adjust the analog gain

[0175] The digital baseband receiver feeds back the analog gain fine adjustment value to the analog RF receiver, and the analog RF receiver uses the analog gain fine adjustment value to adjust the analog gain of the analog baseband signal according to the analog gain adjustment period Use the analog gain to perform amplitude adjustment on the analog baseband signal r n (t), nT A ≤t < (n + 1)T A A After the analog gain is locked, use the analog gain value calculated within the length W of the last analog gain adjustment period A to perform amplitude adjustment on the analog baseband signal r(t), N T A ≤t < T to obtain the analog baseband signal after amplitude adjustment by the analog gain

[0176] 4. Detection of useful signals and elimination of abnormal points

[0177] Calculate the average power of the digital baseband signal within the continuous two digital gain adjustment periods of length W after the analog gain adjustment and D the ratio R and of n , compare R n with the useful signal detection threshold R for useful signal detection. In the i (i = 1, 2,..., N D -1)th digital gain adjustment period of length W D when a useful signal is detected, calculate the average power of the digital baseband signal and the power P of the sampling point m 1, calculate the ratio I m of P and m , compare Im and the size of the anomaly detection threshold I. After detecting an anomaly point, use the anomaly elimination factor K to perform anomaly elimination processing to obtain the sampled points of the digital baseband signal after anomaly elimination

[0178] 5. Calculation of digital gain adjustment value

[0179] According to the digital gain adjustment cycle length W D divide the digital baseband signal y(k) after anomaly elimination into cycles, and calculate the digital baseband signal within the nth (n = 0, 1,..., N D - 1) digital gain adjustment cycle average power Compare with the digital gain target power Calculate the digital gain adjustment value

[0180] 6. Adjust the digital gain

[0181] The digital baseband receiver uses the digital gain adjustment value to adjust the digital gain of the digital baseband signal according to the digital gain adjustment cycle Use the digital gain to perform amplitude adjustment on the digital baseband signal. After the digital gain is locked, use the digital gain value calculated within the last digital gain adjustment cycle length W D to perform amplitude adjustment on the digital baseband signal y(k), k = N D W D , N D W D + 1,..., F s ·T - 1 to obtain the digital baseband signal after amplitude adjustment by digital gain

[0182] The present invention finds that the traditional automatic gain control method has high hardware design requirements, slow gain adjustment speed, and unstable output signal amplitude of the analog radio frequency receiver. Therefore, the present invention adopts a two-stage feedback automatic gain control structure. By comparing the average power of the digital baseband signal and the analog gain target power, the rough adjustment value of the analog gain is calculated. By evaluating the amplitude saturation degree of the digital baseband signal, the fine adjustment value of the analog gain is calculated, which speeds up the convergence speed of the analog gain adjustment. By feeding back the fine adjustment value of the analog gain to the analog radio frequency receiver for analog gain adjustment, the analog gain jitter is reduced, and the first-stage feedback analog automatic gain control is realized. By detecting and eliminating abnormal points of the useful signal, the accuracy of the system frame synchronization is improved. By comparing the average power of the digital baseband signal and the digital gain target power, the digital gain adjustment value is calculated. By adjusting the amplitude of the digital baseband signal with the digital gain value, the stability of the digital baseband signal amplitude is improved, and the second-stage digital automatic gain control is realized. Finally, fast and stable two-stage automatic gain control is realized, which can effectively improve the receiving performance of the wireless communication system, reduce the device power consumption, and save the receiver cost.

[0183] Optionally, the received radio frequency signal is frequency-converted to obtain an analog baseband signal. The analog baseband signal is amplitude-adjusted and analog-to-digital converted through analog gain to obtain a digital baseband signal. The average power of the digital baseband signal is calculated periodically. The average power is compared with the analog gain target power, and the rough adjustment value of the analog gain is calculated, including:

[0184] Assume that the analog baseband signal is r(t), and the analog baseband signal after amplitude adjustment through analog gain is The digital baseband signal is y(k), then the analog baseband signal r n (t) within the analog gain adjustment period is expressed as:

[0185] r n (t) = r(t + nT A ), 0 ≤ t < T A , n = 0, 1, 2, …, N A -1

[0186] where, T A is the analog gain adjustment period time, and N A is the number of analog gain adjustment periods. Then the digital baseband signal within the analog gain adjustment period length is expressed as:

[0187]

[0188] where, W A = F s ·T A is the analog gain adjustment period length, F s is the sampling rate, then The average power It is expressed as:

[0189]

[0190] Among them, L A Calculate the window length for the analog gain, L A <W A , |·| is the complex modulus, compare the average power Target power with analog gain Calculate the analog gain coarse adjustment value It is expressed as:

[0191]

[0192] Optionally, based on the average power of the digital baseband signal, evaluating the amplitude saturation degree of the digital baseband signal includes:

[0193] Assume that the three power saturation thresholds are P1, P2 and P3 respectively, and the conditions are met

[0194] When the analog gain adjusts the cycle length W A The average power within Greater than analog gain target power Right now When the analog gain coarse adjustment value is At this time, by comparing The amplitude saturation degree of the digital baseband signal y(k) is determined by the size of P1, P2 and P3:

[0195] like Greater than or equal to P1, that is Then it is determined that the amplitude saturation of y(k) is high;

[0196] like Greater than or equal to P2 and less than P1, that is Then it is judged that the amplitude saturation of y(k) is moderate;

[0197] like Greater than or equal to P3 and less than P2, that is Then it is determined that the amplitude saturation of y(k) is low;

[0198] like Less than P3, that is Then it is determined that the amplitude of y(k) is not saturated;

[0199] When the analog gain adjusts the cycle length W A The average power within Less than or equal to the analog gain target power Right now When, the rough adjustment value of the analog gain Do not compare at this time With the magnitudes of P1, P2, and P3, it is determined that the magnitude of the digital baseband signal y(k) is not saturated.

[0200] Optionally, based on the average power of the digital baseband signal, evaluate the magnitude saturation degree of the digital baseband signal. According to the magnitude saturation degree of the digital baseband signal, fine-tune the rough adjustment value of the analog gain through the analog gain adjustment value increment factor, and calculate the fine adjustment value of the analog gain, including:

[0201] Assume that the analog gain adjustment value increment factors are G1, G2, and G3, and satisfy the condition G1 > G2 > G3 > 0. Calculate the analog gain adjustment cycle length W according to the magnitude saturation degree of the digital baseband signal y(k) A The fine adjustment value of the analog gain within

[0202] If the magnitude saturation degree of the digital baseband signal y(k) is high, then use the analog gain adjustment value increment factor G1 to Fine-tune the rough adjustment value of the analog gain and calculate the fine adjustment value of the analog gain Expressed as:

[0203]

[0204] If the magnitude saturation degree of the digital baseband signal y(k) is medium, then use the analog gain adjustment value increment factor G2 to Fine-tune the rough adjustment value of the analog gain and calculate the fine adjustment value of the analog gain Expressed as:

[0205]

[0206] If the magnitude saturation degree of the digital baseband signal y(k) is low, then use the analog gain adjustment value increment factor G3 to Fine-tune the rough adjustment value of the analog gain and calculate the fine adjustment value of the analog gain Expressed as:

[0207]

[0208] If the magnitude of the digital baseband signal y(k) is not saturated, then do not Fine-tune the rough adjustment value of the analog gain, and the fine adjustment value of the analog gain Expressed as:

[0209]

[0210] Optionally, the analog gain fine adjustment value is fed back to the analog RF receiver. The analog RF receiver adjusts the analog gain of the down-converted analog baseband signal periodically based on the analog gain fine adjustment value, and uses the analog gain value to adjust the amplitude of the analog baseband signal, obtaining the analog baseband signal after analog gain adjustment amplitude, realizing the first-stage feedback analog automatic gain control, including:

[0211] The amplitude adjustment process includes an analog gain adjustment stage and an analog gain locking stage. Within the analog gain adjustment cycle length W A the analog gain is adjusted with the analog gain fine adjustment value and the analog gain value is calculated which is expressed as:

[0212]

[0213] wherein, is the initial analog gain value. In the analog gain adjustment stage, the analog baseband signal r A within the analog gain adjustment cycle length W is amplitude-adjusted with the calculated analog gain value A for the analog baseband signal r n (t) within the analog gain adjustment cycle time T A In the analog gain locking stage, the analog gain value is locked to the analog gain value calculated within the last analog gain adjustment cycle length W to amplitude-adjust the analog baseband signal r(t), N A T A ≤t<T, obtaining the analog baseband signal after analog gain adjustment amplitude which is expressed as:

[0214]

[0215] wherein, T is the duration of the analog baseband signal, T≥N A T A ;

[0216] Optionally, the digital baseband signal after analog gain adjustment amplitude is subjected to useful signal detection and abnormal point detection and elimination processing, including:

[0217] Useful signal detection is performed by comparing the average power change of the digital baseband signal within two consecutive digital gain adjustment cycles after analog gain adjustment amplitude. The average power of the digital baseband signal is calculated according to the digital gain adjustment cycle, and the digital baseband signal within the digital gain adjustment cycle length is expressed as:

[0218]

[0219] Among them, W D is the length of the digital gain adjustment period, and N D is the number of digital gain adjustment periods. Then The average power of is expressed as:

[0220]

[0221] Among them, L D is the length of the digital gain calculation window, and L D <W D ;

[0222] Useful signal detection is performed by comparing the average power changes of the digital baseband signals within two consecutive digital gain adjustment periods, including:

[0223] (1) Calculate the ratio R D of the average power and of the digital baseband signal within two consecutive digital gain adjustment periods of length W n , which is expressed as:

[0224]

[0225] (2) Compare with for the ratio R n and the useful signal detection threshold R:

[0226] a) If R n is greater than or equal to R, that is, R n ≥R, then it is determined that a useful signal is detected, and the useful signal detection ends;

[0227] b) If R n is less than R, that is, R n <R, then it is determined that no useful signal is detected, n = n + 1. If n ≤ N D -1, then return to step (1) to restart the useful signal detection; if n > N D -1, end the useful signal detection.

[0228] Optionally, useful signal detection and abnormal point detection and elimination processing are performed on the digital baseband signal after the analog gain adjustment amplitude to obtain the sampled points of the digital baseband signal after elimination, including:

[0229] During the digital gain adjustment period when a useful signal is detected, abnormal point detection and elimination processing are performed by comparing the power of the sampled points and the average power. Assume that for the i-th (i = 1, 2,..., N DIf a useful signal is detected in the (i - 1)th digital gain adjustment period, then the length W of the ith digital gain adjustment period D of the digital baseband signal average power is expressed as:

[0230]

[0231] During the digital gain adjustment period when a useful signal is detected, abnormal point detection and elimination processing are performed by comparing the power of the sampling points and the average power. Specifically, it includes:

[0232] (1) Within the length W of the ith digital gain adjustment period D calculate the power P of the sampling points of the digital baseband signal , which is expressed as: m

[0233]

[0234] (2) Calculate the ratio I m of the sampling point power Pand the average power , which is expressed as: m

[0235]

[0236] (3) Compare the ratio I m of the sampling point power Pand the average power with the abnormal point detection threshold I: m

[0237] a) If I m is greater than or equal to I, that is, I m ≥I, then it is determined that the sampling point of the digital baseband signal is an abnormal point, and the abnormal point elimination factor K is used to perform abnormal point elimination processing on to obtain the sampling point of the digital baseband signal after elimination, which is expressed as:

[0238]

[0239] b) If I m is less than I, that is, I m <I, then it is determined that the sampling point of the digital baseband signal is a normal point, and no abnormal point elimination processing is performed on .

[0240] Optionally, according to the sampling points of the digital baseband signal after anomaly point elimination, calculate the average power of the digital baseband signal after anomaly point elimination at a period, and calculate the digital gain adjustment value after anomaly point elimination based on the average power and the digital gain target power, including:

[0241] Calculate the average power of the digital baseband signal after anomaly point elimination and the digital gain adjustment value at a digital gain adjustment period. Within the digital gain adjustment period length W D calculate the average power of the digital baseband signal after anomaly point elimination Expressed as:

[0242]

[0243] Based on the average power and the digital gain target power calculate the digital gain adjustment value Expressed as:

[0244]

[0245] Optionally, adjust the digital gain of the digital baseband signal after anomaly point elimination at a period, and perform amplitude adjustment on the digital baseband signal based on the digital gain value to achieve the second-level digital automatic gain control, including:

[0246] The amplitude adjustment process includes a digital gain adjustment stage and a digital gain locking stage. Within the digital gain adjustment period length W D use the digital gain adjustment value to adjust the digital gain to obtain the digital gain value Expressed as:

[0247]

[0248] In the digital gain adjustment stage, use the digital gain value to perform amplitude adjustment on the digital baseband signal at a digital gain adjustment period. In the digital gain locking stage, lock the digital gain value as the digital gain value calculated within the last digital gain adjustment period length W D to perform amplitude adjustment on the digital baseband signal y(k), k = N W D W D , N D W D +1, …, F s ·T - 1 to obtain the digital baseband signal after digital gain adjustment amplitude Expressed as:

[0249]

[0250] Therefore, by placing the automatic gain control loop between the analog RF receiver and the digital baseband receiver, the analog RF receiver calculates the feedback gain control codeword using digital circuits to control and adjust the variable gain amplifier, achieving automatic gain control. This can effectively reduce the hardware design requirements, improve the stability of the output signal, and save the receiver cost.

[0251] Without increasing the circuit complexity and meeting the requirements of low power consumption and low latency, the present invention designs a two-stage automatic gain control method. The first stage is an analog automatic gain control with a feedback structure to accelerate the convergence speed of analog gain adjustment. The second stage is a digital automatic gain control to improve the stability of the digital baseband signal amplitude and the accuracy of system frame synchronization, minimizing the receiver cost, which is of great significance for improving the receiving performance of wireless communication systems.

[0252] According to another aspect of the present invention, a two-mode wireless communication two-stage feedback automatic gain control system 400 is also provided. As shown in Figure 4 Figure [not shown], the system 400 includes:

[0253] An analog gain coarse adjustment value calculation module 410, configured to receive a radio frequency signal, perform frequency conversion to obtain an analog baseband signal, obtain a digital baseband signal by adjusting the amplitude of the analog baseband signal through analog gain and performing analog-to-digital conversion, calculate the average power of the digital baseband signal at regular intervals, compare the average power with the analog gain target power, and calculate the analog gain coarse adjustment value;

[0254] An analog gain fine adjustment value calculation module 420, configured to evaluate the amplitude saturation degree of the digital baseband signal based on the average power of the digital baseband signal, and fine-tune the analog gain coarse adjustment value according to the amplitude saturation degree of the digital baseband signal through an analog gain adjustment value increment factor to calculate the analog gain fine adjustment value;

[0255] A first feedback automatic gain control module 430, configured to feedback the analog gain fine adjustment value to the analog RF receiver. The analog RF receiver adjusts the analog gain of the down-converted analog baseband signal at regular intervals based on the analog gain fine adjustment value, and adjusts the amplitude of the analog baseband signal using the analog gain value to obtain an analog baseband signal after analog gain amplitude adjustment, implementing the first-stage feedback analog automatic gain control;

[0256] A digital baseband signal detection module 440, configured to perform useful signal detection and abnormal point detection and elimination processing on the digital baseband signal after analog gain amplitude adjustment to obtain digital baseband signal sampling points after abnormal point elimination;

[0257] The digital gain adjustment value calculation module 450 is configured to calculate the average power of the digital baseband signal after anomaly point elimination according to the sampling points of the digital baseband signal after anomaly point elimination in a cycle, and calculate the digital gain adjustment value after anomaly point elimination based on the average power and the digital gain target power;

[0258] The second feedback automatic gain control module 460 is configured to adjust the digital gain of the digital baseband signal after anomaly point elimination in a cycle, and perform amplitude adjustment on the digital baseband signal based on the digital gain value to implement the second-stage digital automatic gain control.

[0259] A two-mode wireless communication two-stage feedback automatic gain control system 400 according to an embodiment of the present invention corresponds to a two-mode wireless communication two-stage feedback automatic gain control method 100 according to another embodiment of the present invention, and will not be elaborated herein.

[0260] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of the present application can be implemented in various computer languages, for example, object-oriented programming languages such as Java and interpreted scripting languages such as JavaScript.

[0261] The present application is described with reference to the flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, as well as the combination of flows and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate for implementing in the process Figure 1 a process or multiple processes and / or blocks Figure 1 a block or multiple blocks to specify the function of the device.

[0262] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device, and the instruction device implements in the process Figure 1 a process or multiple processes and / or blocks Figure 1The functions specified in one or more boxes.

[0263] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process. Thus, the instructions executed on the computer or other programmable device provide for implementing the steps of the functions specified in one Figure 1 process or more processes and / or boxes Figure 1 or more boxes.

[0264] Although the preferred embodiments of the present application have been described, those skilled in the art can make additional changes and modifications once they learn the basic creative concepts. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications that fall within the scope of the present application.

[0265] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these modifications and variations.

Claims

1. A two - mode wireless communication two - stage feedback automatic gain control method, characterized in that Including: Receiving a radio frequency signal, performing frequency conversion to obtain an analog baseband signal, adjusting the amplitude of the analog baseband signal through analog gain and performing analog-to-digital conversion to obtain a digital baseband signal, calculating the average power of the digital baseband signal periodically, comparing the average power with the analog gain target power, and calculating the rough analog gain adjustment value; Based on the average power of the digital baseband signal, evaluating the amplitude saturation degree of the digital baseband signal, and according to the amplitude saturation degree of the digital baseband signal, finely adjusting the rough analog gain adjustment value through the analog gain adjustment value increment factor to calculate the fine analog gain adjustment value; Feeding back the fine analog gain adjustment value to the analog radio frequency receiver, the analog radio frequency receiver adjusting the analog gain of the down-converted analog baseband signal periodically based on the fine analog gain adjustment value, and using the analog gain value to adjust the amplitude of the analog baseband signal to obtain the analog baseband signal after analog gain amplitude adjustment, thereby implementing the first-level feedback analog automatic gain control; Performing useful signal detection and abnormal point detection and elimination processing on the digital baseband signal after analog gain amplitude adjustment to obtain the sampled points of the digital baseband signal after abnormal point elimination; According to the sampled points of the digital baseband signal after abnormal point elimination, calculating the average power of the digital baseband signal after abnormal point elimination periodically, and based on the average power and the digital gain target power, calculating the digital gain adjustment value after abnormal point elimination; Adjusting the digital gain of the digital baseband signal after abnormal point elimination periodically, and based on the digital gain value, adjusting the amplitude of the digital baseband signal to implement the second-level digital automatic gain control.

2. The method according to claim 1, wherein Receiving a radio frequency signal, performing frequency conversion to obtain an analog baseband signal, adjusting the amplitude of the analog baseband signal through analog gain and performing analog-to-digital conversion to obtain a digital baseband signal, calculating the average power of the digital baseband signal periodically, comparing the average power with the analog gain target power, and calculating the rough analog gain adjustment value, including: Assume that the analog baseband signal is r(t), and the analog baseband signal after adjusting the amplitude by analog gain is The digital baseband signal is y(k), then the analog baseband signal r n (t) during the analog gain adjustment period is expressed as: r n r(t) = r(t + nT A ), 0 ≤ t < T A , n = 0, 1, 2, …, N A -1 Among them, T A is the analog gain adjustment cycle time, and N A is the number of analog gain adjustment cycles. Then, the digital baseband signal within the length of the analog gain adjustment cycle is expressed as: Among them, W A = F s · T A is the length of the analog gain adjustment period, F s is the sampling rate, then The average power of is expressed as: Among them, L A is the length of the simulation gain calculation window, L A < W A , |·| is the modulus of a complex number, compare the average power with the simulation gain target power to calculate the rough adjustment value of the simulation gain which is expressed as:

3. The method according to claim 2, characterized in that, Based on the average power of the digital baseband signal, evaluating the amplitude saturation degree of the digital baseband signal, including: Assume that the three-level power saturation thresholds are P1, P2, and P3 respectively, and satisfy the condition When the average power within the analog gain adjustment cycle length W A is greater than the analog gain target power That is at this time, the analog gain coarse adjustment value At this time, by comparing with the magnitudes of P1, P2, and P3, the amplitude saturation degree of the digital baseband signal y(k) is judged:​ If is greater than or equal to P1, that is it is determined that the amplitude saturation degree of y(k) is high; If is greater than or equal to P2 and less than P1, that is then it is determined that the amplitude saturation degree of y(k) is medium; If is greater than or equal to P3 and less than P2, that is then it is determined that the amplitude saturation degree of y(k) is low; If less than P3, that is it is determined that the amplitude of y(k) is not saturated; When the average power within the analog gain adjustment cycle length W A is less than or equal to the analog gain target power that is when the rough adjustment value of the analog gain at this time, no comparison is made with the magnitudes of P1, P2, and P3, and it is determined that the amplitude of the digital baseband signal y(k) is not saturated.

4. The method according to claim 3, wherein Based on the average power of the digital baseband signal, evaluating the amplitude saturation degree of the digital baseband signal, and according to the amplitude saturation degree of the digital baseband signal, finely adjusting the rough analog gain adjustment value through the analog gain adjustment value increment factor to calculate the fine analog gain adjustment value, including: Assume that the analog gain adjustment value increment factors are G1, G2, and G3, and satisfy the condition G1 > G2 > G3 > 0. Calculate the analog gain fine adjustment value within the analog gain adjustment cycle length W according to the amplitude saturation degree of the digital baseband signal y(k). A The analog gain fine adjustment value within If the amplitude saturation degree of the digital baseband signal y(k) is high, then the analog gain coarse adjustment value is finely adjusted using the analog gain adjustment value increment factor G1, and the analog gain fine adjustment value is calculated and is expressed as: which is expressed as: If the saturation degree of the amplitude of the digital baseband signal y(k) is medium, then the analog gain coarse adjustment value is finely adjusted with the analog gain adjustment value increment factor G2, and the analog gain fine adjustment value is calculated which is expressed as: as follows: If the saturation degree of the amplitude of the digital baseband signal y(k) is low, the coarse adjustment value of the analog gain is finely adjusted with the analog gain adjustment value increment factor G3, and the fine adjustment value of the analog gain is calculated which is expressed as: which is expressed as: If the amplitude of the digital baseband signal y(k) is not saturated, the coarse adjustment value of the analog gain is not fine-tuned, and the fine adjustment value of the analog gain is expressed as:

5. The method according to claim 4, wherein Feeding back the fine analog gain adjustment value to the analog radio frequency receiver, the analog radio frequency receiver adjusting the analog gain of the down-converted analog baseband signal periodically based on the fine analog gain adjustment value, and using the analog gain value to adjust the amplitude of the analog baseband signal to obtain the analog baseband signal after analog gain amplitude adjustment, thereby implementing the first-level feedback analog automatic gain control, including: The amplitude adjustment process includes an analog gain adjustment phase and an analog gain locking phase. During the analog gain adjustment cycle length W A within, the analog gain is adjusted with the analog gain fine adjustment value and the analog gain value is calculated which is expressed as: Among them, is the initial analog gain value. During the analog gain adjustment phase, the analog gain value calculated within the analog gain adjustment period length W A is used to perform amplitude adjustment on the analog baseband signal r A (t) within the analog gain adjustment period time T n . During the analog gain locking phase, the analog gain value is locked to the analog gain value calculated within the last analog gain adjustment period length W A . Perform amplitude adjustment on the analog baseband signal r(t), N A T A ≤t<T to obtain the analog baseband signal after analog gain adjustment amplitude, which is expressed as: It is expressed as: where T is the duration of the analog baseband signal, and T ≥ N A T A .

6. The method according to claim 5, wherein Performing useful signal detection and abnormal point detection and elimination processing on the digital baseband signal after analog gain amplitude adjustment, including: Useful signal detection is performed by comparing the average power change of the digital baseband signal in two consecutive digital gain adjustment periods after the analog gain adjustment amplitude is passed. The average power of the digital baseband signal is calculated according to the digital gain adjustment period, and the digital baseband signal within the digital gain adjustment period length is expressed as: Where, W D is the digital gain adjustment cycle length, and N D is the number of digital gain adjustment cycles. Then the average power is expressed as: Among them, L D is the digital gain calculation window length, L D < W D ; Performing useful signal detection by comparing the change in the average power of the digital baseband signal in two consecutive digital gain adjustment periods, including: (1) Calculate the average power of the digital baseband signal within the length W of two consecutive digital gain adjustment periods D and the ratio R of is expressed as: n ​ (2) Comparison with to obtain the ratio R n and compare it with the useful signal detection threshold R: a) If R n is greater than or equal to R, i.e., R n ≥ R, it is determined that a useful signal is detected, and the detection of the useful signal ends; b) If R n is less than R, that is, R n <R, it is determined that no useful signal is detected, n = n + 1. If n ≤ N D - 1, return to step (1) to restart the detection of useful signals; if n > N D - 1, end the detection of useful signals.

7. The method according to claim 6, wherein Performing useful signal detection and abnormal point detection and elimination processing on the digital baseband signal after analog gain amplitude adjustment to obtain the sampled points of the digital baseband signal after elimination, including: During the digital gain adjustment period when a useful signal is detected, anomaly detection and elimination processing are performed by comparing the power of the sampling points and the average power. Assume that a useful signal is detected in the i-th (i = 1, 2, …, N D −1) digital gain adjustment period, then the length W of the i-th digital gain adjustment period D of the digital baseband signal average power is expressed as: During the digital gain adjustment period when a useful signal is detected, perform anomaly detection and elimination processing by comparing the power of sampling points and the average power. Specifically, it includes: (1) During the length W of the i-th digital gain adjustment period D calculate the sampling points of the digital baseband signal and the power P m which is expressed as: (2) Calculate the power P of the sampling point m and the average power ratio I m , expressed as: (3) Compare the power P of the sampling point m with the average power to obtain the ratio I m and compare it with the anomaly detection threshold I: a) If I m is greater than or equal to I, that is, I m ≥I, then it is determined that the sampling point of the digital baseband signal is an abnormal point, and the abnormal point elimination factor K is used to perform abnormal point elimination processing on it to obtain the sampling point of the digital baseband signal after elimination which is expressed as: b) If I m is less than I, that is, I m <I, then it is determined that the sampling points of the digital baseband signal are normal points and no abnormal point elimination processing is performed.

8. The system according to claim 7, wherein Based on the sampling points of the digital baseband signal after anomaly elimination, calculate the average power of the digital baseband signal after anomaly elimination at regular intervals. Based on the average power and the digital gain target power, calculate the digital gain adjustment value after anomaly elimination, including: Calculate the average power of the digital baseband signal after eliminating abnormal points and the digital gain adjustment value according to the digital gain adjustment period, within the digital gain adjustment period length W D Calculate the average power of the digital baseband signal after eliminating abnormal points It is expressed as: Based on the average power and the digital gain target power calculate the digital gain adjustment value which is expressed as:

9. The system according to claim 8, characterized in that, Adjust the digital gain of the digital baseband signal after anomaly elimination at regular intervals, and perform amplitude adjustment on the digital baseband signal based on the digital gain value to achieve the second-level digital automatic gain control, including: The amplitude adjustment process includes a digital gain adjustment stage and a digital gain locking stage. During the digital gain adjustment cycle length W D within, the digital gain is adjusted using the digital gain adjustment value to obtain the digital gain value which is expressed as: In the digital gain adjustment stage, the digital gain value is used to adjust the amplitude of the digital baseband signal according to the digital gain adjustment period In the digital gain locking stage, the digital gain value is locked to the digital gain value calculated within the length W of the last digital gain adjustment period D to adjust the amplitude of the digital baseband signal y(k), where k = N W D W D , N D W D +1, …, F s ·T - 1, and the digital baseband signal after the digital gain adjustment amplitude is obtained which is expressed as:

10. A two-mode wireless communication two-stage feedback automatic gain control system, characterized in that, It includes: A module for calculating the rough analog gain adjustment value, which is used to receive a radio frequency signal, perform frequency conversion to obtain an analog baseband signal, subject the analog baseband signal to analog gain adjustment amplitude and analog-to-digital conversion to obtain a digital baseband signal, calculate the average power of the digital baseband signal at regular intervals, compare the average power with the analog gain target power, and calculate the rough analog gain adjustment value; A module for calculating the fine analog gain adjustment value, which is used to evaluate the amplitude saturation degree of the digital baseband signal based on the average power of the digital baseband signal, and fine-tune the rough analog gain adjustment value according to the amplitude saturation degree of the digital baseband signal by means of the analog gain adjustment value increment factor to calculate the fine analog gain adjustment value; The first feedback automatic gain control module is used to feedback the fine analog gain adjustment value to the analog radio frequency receiver. The analog radio frequency receiver adjusts the analog gain of the down-converted analog baseband signal at regular intervals based on the fine analog gain adjustment value, and performs amplitude adjustment on the analog baseband signal using the analog gain value to obtain the analog baseband signal after analog gain adjustment amplitude, thereby achieving the first-level feedback analog automatic gain control; A module for detecting the digital baseband signal is used to perform useful signal detection and anomaly detection and elimination processing on the digital baseband signal after analog gain adjustment amplitude to obtain the sampling points of the digital baseband signal after anomaly elimination; A module for calculating the digital gain adjustment value is used to calculate the average power of the digital baseband signal after anomaly elimination at regular intervals based on the sampling points of the digital baseband signal after anomaly elimination, and calculate the digital gain adjustment value after anomaly elimination based on the average power and the digital gain target power; The second feedback automatic gain control module is used to adjust the digital gain of the digital baseband signal after anomaly elimination at regular intervals, and perform amplitude adjustment on the digital baseband signal based on the digital gain value to achieve the second-level digital automatic gain control.

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