Digital-analog hybrid AGC control method and AGC control system in TDMA mode

Abstract

The embodiment of the invention provides a digital-analog hybrid AGC (Automatic Gain Control) control method and an AGC control system in a TDMA (Time Division Multiple Access) mode, and relates to the technical field of power control in a wireless communication system, the method comprises the following steps: in a receiving time slot of a wireless user, configuring the decibel of a digital control attenuator of the wireless user, calculating a signal power estimation value after ADC sampling after the start of the receiving time slot; setting a dynamic range of the ADC, and determining an expected signal power threshold based on the dynamic range of the ADC; and performing AGC control based on the signal power estimation value, the dynamic range of the ADC and the expected signal power threshold, and adjusting the decibel of the numerical control attenuator. According to the technical scheme, feedforward control and feedback control are combined in the TDMA mode, and the dual advantages of fast response and large dynamic are achieved.

Description

Technical Field

[0001] The present application relates to the technical field of power control in a wireless communication system, and in particular to a digital-analog hybrid AGC control method and an AGC control system in a TDMA mode. Background Art

[0002] In wireless communication, the Time Division Multiple Access (TDMA) mode divides time resources into time slots, and stipulates that each user in the network occupies the entire bandwidth for transmission in a specific time slot and receives in other time slots. Therefore, multiple users can share a carrier frequency, the RF channel is relatively simple, the network construction is relatively easy, and the system stability is high. This advantage makes the TDMA mode occupy an important position in the field of civil or military communications that pursue high stability.

[0003] In TDMA mode, the distances between multiple users in the network may vary greatly, and the channel environments of different users are also different, resulting in a large dynamic range of power when the signals sent by different users reach a specific user. Too large a signal may saturate the analog-digital converter (ADC), and too small a signal may be submerged in noise and cannot be effectively collected by the ADC. Therefore, AGC control of the signal power is necessary.

[0004] Under current technical conditions, power AGC control is mainly divided into closed-loop control and open-loop control. Open-loop control is generally divided into feedforward control and feedback control. Feedforward control mainly estimates the power of the digital signal after ADC sampling, then compares the estimated signal power with the expected power value, uses a certain algorithm to obtain the gain value to be controlled, and finally controls the power of the digital signal after ADC sampling, which belongs to the digital domain. The advantage of the feedforward control method is that the processing rate is fast and the changes in signal power can be tracked in time. The disadvantage is that the dynamic range is small and it can only work normally within the dynamic range of the ADC.

[0005] The main difference between feedback control and feedforward control is that after obtaining the gain value to be controlled, feedback control uses the signal power before ADC sampling to control, which belongs to the analog domain. Therefore, feedback control has the disadvantages of slow processing rate and untimely response, but it has a large dynamic range of adaptability. The range of power control mainly depends on the size of the front-end variable gain amplifier or attenuator.

[0006] Combining feedforward control and feedback control can achieve the dual advantages of large dynamics and timely response. However, how the two can cooperate in power control is a difficulty in the current TDMA communication mode. Summary of the invention

[0007] The embodiments of the present application provide a digital-analog hybrid AGC control method and an AGC control system in a TDMA mode to solve the problem that fast response and large dynamics are difficult to meet simultaneously in the TDMA mode.

[0008] Other features and advantages of the present application will become apparent from the following detailed description, or may be learned in part by the practice of the present application.

[0009] According to a first aspect of an embodiment of the present application, a digital-analog hybrid AGC control method in a TDMA mode is provided, which is implemented by an AGC control system and includes:

[0010] In a receiving time slot of a wireless user, configuring the decibel of a digitally controlled attenuator of the wireless user, and calculating an estimated value of signal power after ADC sampling after the start of the receiving time slot;

[0011] Setting a dynamic range of the ADC, and determining a desired signal power threshold based on the dynamic range of the ADC;

[0012] AGC control is performed based on the signal power estimation value, the dynamic range of the ADC and the expected signal power threshold, and the decibel of the digitally controlled attenuator is adjusted.

[0013] In some embodiments of the present application, based on the above scheme, the step of calculating the estimated signal power value after ADC sampling after the start of the receiving time slot includes:

[0014] Get the absolute value of the real part and the absolute value of the imaginary part of the ADC sampling value;

[0015] Calculating the signal power estimation value based on formula (1);

[0016]

[0017] In formula (1), P cal Represents the signal power estimation value, N represents the number of sampling points, |RE i | represents the absolute value of the real part of the i-th ADC sampling value, |IM i | represents the absolute value of the imaginary part of the i-th ADC sampling value.

[0018] In some embodiments of the present application, based on the above solution, determining the expected signal power threshold based on the dynamic range of the ADC includes:

[0019] Based on the dynamic range of the ADC, the lower limit of the desired signal power threshold is determined using formula (2);

[0020] P′ low =0.5×[P low+P high ]-10; (2)

[0021] In formula (2), P′ low Represents the lower limit of the desired signal power threshold, P low Represents the dynamic lower limit of the ADC, P high Indicates the dynamic upper limit value of the ADC;

[0022] Based on the dynamic range of the ADC, the upper limit value of the desired signal power threshold is determined using formula (3);

[0023] P′ high =0.5×[P low +P high ]+10; (3)

[0024] In formula (3), P′ high represents the upper limit of the desired signal power threshold, Pl ow Represents the dynamic lower limit of the ADC, P high Indicates the dynamic upper limit value of the ADC.

[0025] In some embodiments of the present application, based on the above scheme, performing AGC control based on the signal power estimation value, the dynamic range of the ADC and the expected signal power threshold, and adjusting the decibel of the digitally controlled attenuator includes:

[0026] If P cal >P high -T, then the feedback gain control function is activated to increase the decibel of the digitally controlled attenuator;

[0027] If P cal <P low +T, the feedback gain control function is activated to reduce the decibel of the digitally controlled attenuator;

[0028] If P′ high <P cal ≤P high -T or P′ low >P cal ≥P low +T, the feedforward gain control function is started, the decibel of the digitally controlled attenuator is not adjusted, and power control is performed according to the relationship between the desired signal power threshold and the signal power estimation value;

[0029] Among them, P cal Represents the signal power estimate, P high Indicates the dynamic upper limit of ADC, P low represents the dynamic lower limit of ADC, T represents the signal power protection value, P′high Represents the upper limit of the desired signal power threshold, P′ low Indicates the lower limit of the expected signal power threshold.

[0030] In some embodiments of the present application, based on the aforementioned solution, the signal power protection value is 6 decibels.

[0031] In some embodiments of the present application, based on the above solution, the difference between the upper limit value of the expected signal power threshold and the lower limit value of the expected signal power threshold is 20 decibels.

[0032] In some embodiments of the present application, based on the above solution, the power control is performed according to the relationship between the expected signal power threshold and the signal power estimation value, including:

[0033] If P cal >P′ high , then the signal power estimation value after ADC sampling is reduced, and the reduced value is P cal -P′ high ;

[0034] If P cal <P′ low , then the signal power estimation value after ADC sampling is increased, and the increased value is P′ low -P cal ;

[0035] If P′ low ≤P cal ≤P′ high , the signal power estimation value after ADC sampling remains unchanged.

[0036] According to a second aspect of an embodiment of the present application, an AGC control system is provided, comprising: a digitally controlled attenuator, an ADC, a power detection and controller, and a digital gain generator connected in sequence;

[0037] Wherein, the power detection and controller is also connected to the digitally controlled attenuator to realize feedback power control;

[0038] The power detection and controller is also connected to the digital gain generator to implement feedforward power control.

[0039] The advantages of the technical solution of this application compared with the prior art are as follows:

[0040] (1) Compared with the traditional adaptive power control method, the present invention has the advantages of short response time and large dynamic range. The response time can be shortened to hundreds of nanoseconds, and the dynamic range can be extended by more than 20 decibels on the ADC dynamic range. At the same time, setting the high and low thresholds of the desired signal power can take into account both the response time and the power stability.

[0041] (2) This application is particularly suitable for short-time slot, multi-user networking communication scenarios under TDMA mode. It can solve problems such as far-near effect, individual power difference, channel difference, etc. among multiple users, and ensure that users can switch smoothly between large dynamic signal powers.

[0042] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The drawings herein are incorporated into the specification and constitute a part of the specification, showing embodiments consistent with the present application, and together with the specification, are used to explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0044] Figure 1 A block diagram of an AGC control system according to an embodiment of the present application is shown;

[0045] Figure 2 A schematic flow chart of a digital-analog hybrid AGC control method in TDMA mode according to an embodiment of the present application is shown;

[0046] Figure 3 A schematic diagram of an automatic gain control strategy according to an embodiment of the present application is shown;

[0047] Figure 4 A flowchart of an implementation according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0048] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this application will be more comprehensive and complete and fully convey the concept of the example embodiments to those skilled in the art.

[0049] In addition, described feature, structure or characteristic can be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present application. However, those skilled in the art will appreciate that the technical scheme of the present application can be put into practice without one or more of the specific details, or other methods, components, devices, steps, etc. can be adopted. In other cases, known methods, devices, realizations or operations are not shown or described in detail to avoid blurring the various aspects of the application.

[0050] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities may be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0051] The flowcharts shown in the accompanying drawings are only exemplary and do not necessarily include all the contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps can be decomposed, and some operations / steps can be combined or partially combined, so the actual execution order may change according to actual conditions.

[0052] It should be noted that the "multiple" mentioned in this article refers to two or more. "And / or" describes the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0053] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, not all the embodiments. Based on the embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] Some embodiments of the present application will be described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments may be combined with each other.

[0055] In order to solve the problem that fast response and large dynamics are difficult to meet simultaneously in TDMA mode, the present application proposes a digital-analog hybrid AGC control method in TDMA mode. The method adopts an open-loop method, combines feedforward control with feedback control, and quickly adjusts the power to a reasonable range when the signal arrives, thereby ensuring the detection probability of the signal. At the same time, it combines the RF attenuation and the dynamics of ADC to increase the dynamic range of the system. It is particularly suitable for multi-user, short time slot, and large dynamic communication systems.

[0056] It should be noted that the digital-analog hybrid AGC control method in TDMA mode provided in the embodiment of the present application needs to be implemented through an AGC control system.

[0057] See also Figure 1 , shows a block diagram of an AGC control system according to an embodiment of the present application.

[0058] like Figure 1 As shown, an AGC control system includes: a digitally controlled attenuator, an ADC, a power detection and controller, and a digital gain generator connected in sequence;

[0059] Wherein, the power detection and controller is connected to the digitally controlled attenuator to realize feedback power control;

[0060] The power detection and controller is connected to the digital gain generator to implement feedforward power control.

[0061] It should be noted that the digitally controlled attenuator is used for feedback power control, the digital gain generator is used for feedforward power control, and the power detection and controller completes the estimation of the signal power after ADC sampling and the generation of feedback and feedforward power control strategies.

[0062] In TDMA mode, the received signal passes through the antenna and analog front end in turn and then enters the automatic gain control system composed of a digitally controlled attenuator, ADC, power detection and controller, and digital gain generator.

[0063] The digital controlled attenuator is combined with the power detection and controller to complete the feedback power control, and the power detection and controller is combined with the digital gain generator to complete the feedforward power control. The power detection and controller is the core of the whole system and is responsible for the scheduling of the system strategy.

[0064] It should be noted that, throughout this application, ADC refers to an analog-to-digital converter.

[0065] See also Figure 2 , shows a flow chart of a digital-analog hybrid AGC control method in TDMA mode according to an embodiment of the present application.

[0066] like Figure 2 As shown, a digital-analog hybrid AGC control method in TDMA mode is shown. The method is implemented by an AGC control system provided by the above embodiment. The method specifically includes steps S100 to S300.

[0067] Step S100, in a receiving time slot of a wireless user, configuring the decibel of a digitally controlled attenuator of the wireless user, and calculating an estimated value of signal power after ADC sampling after the start of the receiving time slot.

[0068] It should be noted that there are multiple wireless users, for example, there are four invalid users A, B, C, and D. Each user is equipped with a wireless communication transceiver, which can realize data communication between each other, and a digitally controlled attenuator is configured in the RF receiving channel of each user. Any user sends a signal in a specified time slot, and receives signals in other time slots.

[0069] In some feasible embodiments, based on the above scheme, the step of calculating the estimated signal power value after ADC sampling after the start of the receiving time slot includes:

[0070] Get the absolute value of the real part and the absolute value of the imaginary part of the ADC sampling value;

[0071] Calculating the signal power estimation value based on formula (1);

[0072]

[0073] In formula (1), P cal represents the signal power estimation value, N represents the number of sampling points, |RE i | represents the absolute value of the real part of the i-th ADC sampling value, |IM i | represents the absolute value of the imaginary part of the i-th ADC sampling value.

[0074] It can be understood that in this embodiment, the signal power estimation value is obtained through the power approximation estimation algorithm. This calculation method reduces the calculation complexity while obtaining the signal power approximation value, and the calculation can be completed with only N additions and one division.

[0075] Exemplarily, taking user A as an example, assuming that the current time slot is the transmission time slot of user A, the automatic gain control function of user A is turned off.

[0076] Assuming that the current time slot is the receiving time slot of user A, the digital controlled attenuator of A is configured to RX decibel, and the signal power value after ADC sampling is counted after the time slot starts.

[0077] The sampling rate is K times the symbol rate, and the K value needs to be greater than 4 to ensure that the sampling points can fully reflect the signal amplitude. The number of statistical samples is N, and this value needs to be appropriate. Too large will result in a long response time, and too small will result in signal power jitter. It can generally be set to 8K~32K, that is, the number of statistical samples is 8~32 symbols.

[0078] Then, the signal power estimation value is calculated using the above formula (1).

[0079] It should be noted that, for the signal power estimation value, the mapping from the dimensionless calculated value to the signal power needs to be based on the ADC value-power mapping table, and the difference between the two is ignored here.

[0080] Continue to refer Figure 2 , step S200, setting the dynamic range of the ADC, and determining the desired signal power threshold based on the dynamic range of the ADC.

[0081] In some feasible embodiments, based on the above solution, determining the expected signal power threshold based on the dynamic range of the ADC includes:

[0082] Based on the dynamic range of the ADC, the lower limit of the desired signal power threshold is determined using formula (2);

[0083] P′ low =0.5×[P low +P high ]-10; (2)

[0084] In formula (2), P′ low represents the lower limit of the desired signal power threshold, Pl ow Represents the dynamic lower limit of the ADC, P high Indicates the dynamic upper limit value of the ADC;

[0085] Based on the dynamic range of the ADC, the upper limit value of the desired signal power threshold is determined using formula (3);

[0086] P′ high =0.5×[P low +P high ]+10; (3)

[0087] In formula (3), P′ high represents the upper limit of the desired signal power threshold, Pl ow Represents the dynamic lower limit of the ADC, P high Indicates the dynamic upper limit value of the ADC.

[0088] For example, assuming that the dynamic range of the ADC is [P low P high ], where P low is the lower limit of ADC dynamics, P high is the upper limit of ADC dynamics. The desired signal power threshold is [P′ low P′ high ], where P′ low is the lower limit of the desired signal power threshold, P′ high is the upper limit of the desired signal power threshold. In general, design P′ low 0.5×[P low +P high ]-10, P′ high 0.5×[P low +P high ]+10.

[0089] Continue to refer Figure 2, step S300, performing AGC control based on the signal power estimation value, the dynamic range of the ADC and the expected signal power threshold, and adjusting the decibel of the digitally controlled attenuator.

[0090] In some feasible embodiments, based on the above scheme, performing AGC control based on the signal power estimation value, the dynamic range of the ADC and the expected signal power threshold, and adjusting the decibel of the digitally controlled attenuator includes:

[0091] If P cal >P high -T, then the feedback gain control function is activated to increase the decibel of the digitally controlled attenuator;

[0092] If P cal <Pl ow +T, the feedback gain control function is activated to reduce the decibel of the digitally controlled attenuator;

[0093] If P′ high <P cal ≤P high -T or P′ low >P cal ≥P low +T, the feedforward gain control function is started, the decibel of the digitally controlled attenuator is not adjusted, and power control is performed according to the relationship between the desired signal power threshold and the signal power estimation value;

[0094] Among them, P cal Represents the signal power estimate, P high Indicates the dynamic upper limit of ADC, P low represents the dynamic lower limit of ADC, T represents the signal power protection value, P′ high Represents the upper limit of the desired signal power threshold, P′ low Indicates the lower limit of the expected signal power threshold.

[0095] It should be noted that, in this embodiment, the decibel value of the digitally controlled attenuator cannot be exceeded during the process of increasing the decibel value of the digitally controlled attenuator; and the decibel value of the digitally controlled attenuator can be reduced to a minimum of 0 decibel value.

[0096] For example, based on the above examples, see Figure 3 , the entire signal power interval is divided into a feedback power control interval, a feedforward power control interval and an unadjusted power interval.

[0097] If P cal >P high-6, the feedback gain control function is activated to increase the digital attenuator of user A from RX decibels to RX+10 decibels (if the maximum value of the digital attenuator is less than RX+10, the digital attenuator is increased to the maximum value);

[0098] If P cal <P low +6, the feedback gain control function is activated to reduce the digital attenuator of user A from RX dB to RX-10 dB (if RX-10 is less than 0, it is reduced to 0 dB);

[0099] If P′ high <P cal ≤P high -T or P′ low >P cal ≥P low +T, start the feedforward gain control function, keep the digital controlled attenuator of user A unchanged, and perform power control based on the relationship between the expected signal power threshold and the estimated value of the signal power.

[0100] It should be noted that, in this embodiment, the signal power protection value T is set to 6 decibels to prevent the delayed response of the feedback power control from causing the signal power to approach the ADC saturation or the lower limit of the ADC, thereby introducing a nonlinear error. That is, when the signal power estimation value is 6 decibels less than the upper limit of the ADC, or 6 decibels greater than the lower limit of the ADC, the feedback power control function is immediately started, so that the signal power entering the ADC can be ensured to be always in a more reasonable power range.

[0101] It should be noted that, in this embodiment, the upper limit value of the expected signal power threshold differs from the lower limit value of the expected signal power threshold by 20 decibels. Such a setting is mainly to prevent the power estimation value from fluctuating violently due to insufficient statistical time in the case of low signal-to-noise ratio, thereby affecting the signal quality. The value should not be set too large, as it will result in the inability to track the signal power in real time, lose the meaning of adaptive power control, and put forward greater requirements on the dynamics of the back-end signal processing. Generally speaking, a dynamic of 20 decibels is more suitable in the field of signal processing.

[0102] In some feasible embodiments, based on the above solution, performing power control according to the relationship between the expected signal power threshold and the signal power estimation value includes:

[0103] If P cal >P′ high , then the signal power estimation value after ADC sampling is reduced, and the reduced value is P cal -P′ high ;

[0104] If Pcal <P′ low , then the signal power estimation value after ADC sampling is increased, and the increased value is P′ low -P cal ;

[0105] If P′ low ≤P cal ≤P′ high , the signal power estimation value after ADC sampling remains unchanged.

[0106] It is understandable that when P cal >P′ high When P cal <P′ low When P′ low ≤P cal ≤P′ high When , it indicates that the signal power estimation value is in the expected signal power range. In order to prevent the signal from introducing nonlinear errors due to frequent power adjustments, it is necessary to keep the signal power unchanged after ADC sampling.

[0107] It should be noted that the above operations are performed cyclically in the entire receiving time slot with N sampling points as a period, so as to ensure that the signal power is always within the desired power range.

[0108] In summary, by using the AGC control method provided by the above embodiment, in TDMA mode, after the user has just received the signal, if the power exceeds the dynamic range of the ADC, the feedback power control function will be immediately started to adjust the signal power to the dynamic range of the ADC. During the feedback response time, the signal may be distorted, and this effect can be alleviated by setting a reasonable power statistics time. Generally, the synchronization head is at the beginning of the time slot, and slight distortion has little effect on synchronization detection. At other positions in the time slot, since the signal power has undergone a large dynamic adjustment at the starting position, the power fluctuation is relatively small. At this time, feedforward power control is used to track the change of signal power.

[0109] A specific implementation example is provided below.

[0110] See also Figure 4 , set the number of users to 4, the oversampling factor K to 4, the number of statistical samples N to 16, and select the dynamic range of the ADC [P low P high] is -60dBm~0dBm, and the dynamic range of the signal power received by user A from other users is -50dBm~30dBm. It can be seen that the actual signal power dynamic range exceeds the dynamic range of ADC by 20 decibels. Set the expected signal power threshold [P′ low P′ high ] is -40dBm~-20dBm. In the implementation process, considering that user A is in the state of receiving signals, without loss of generality, the process of users B, C, and D sending signals to user A in sequence is simulated by changing the output signal power of each time slot of user B. This method can simplify the synchronization control process in the implementation process and can fully simulate the communication process of four users using TDMA mode.

[0111] The specific implementation steps are as follows:

[0112] Step 1: User A is set to receive signal state, and the receiving attenuation RX is configured to 20 decibels;

[0113] Step 2: User B is set to send a signal so that the signal power is -50 dBm when it reaches user A. The power estimation value, gain control strategy, receiving attenuation value, and digital gain value of user A are recorded when the signal from user B just arrives and after it stabilizes.

[0114] Step 3: User B is set to send a signal so that the signal power is -20 dBm when it reaches user A. The power estimation value, gain control strategy, receiving attenuation value, and digital gain value of user A after the signal from user B reaches user A are recorded.

[0115] Step 4: User D is set to send a signal so that the signal power is 30 dBm when it reaches user A. The power estimation value, gain control strategy, receiving attenuation value, and digital gain value of user A after the signal from user B reaches user A are recorded.

[0116] Step 5: Analyze the relevant parameters recorded in the previous steps.

[0117] According to the method provided by the present application, when the B signal recorded in step 2 just arrives, the signal power estimation value should be around -50dBm (because the signal power is already lower than the lower limit of the ADC dynamics, so the detected signal power is mainly the ADC noise floor), the gain control strategy should be feedback power control, the receiving attenuation value should be 0 decibels, and the digital gain value should be 0 decibels; after the signal power stabilizes, the signal power estimation value should be around -50dBm, the gain control strategy should be feedforward power control, the receiving attenuation value should be 0 decibels, and the digital gain value should be around 10 decibels;

[0118] When the B signal recorded in step 3 just arrives, the signal power estimation value should be around -40dBm, the gain control strategy should be no control, the receiving attenuation value should be 20dB, and the digital gain value should be 0dB; after the signal power stabilizes, the signal power estimation value should be around -40dBm, the gain control strategy should be no control, the receiving attenuation value should be 20dB, and the digital gain value should be around 0dB;

[0119] When the B signal recorded in step 4 just arrives, the signal power estimation value should be around 0dBm (because the signal power is already higher than the upper limit of the ADC dynamics, the ADC is in a saturated state, and the detected signal power is the ADC dynamic upper limit power), the gain control strategy should be feedback power control, the receiving attenuation value should be 20 decibels, and the digital gain value should be 0 decibels; after the signal power stabilizes, the signal power estimation value should be around -10dBm, the gain control strategy should be feedforward power control, the receiving attenuation value should be 40 decibels, and the digital gain value should be around -10 decibels.

[0120] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the embodiments disclosed herein. The present application is intended to cover any variations, uses or adaptations of the present application, which follow the general principles of the present application and include common knowledge or customary techniques in the art that are not disclosed in the present application. It should be understood that the present application is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A digital-analog hybrid AGC control method in TDMA mode, implemented by an AGC control system, characterized in that: include: In a receiving time slot of a wireless user, configuring the decibel of a digitally controlled attenuator of the wireless user, and calculating an estimated value of signal power after ADC sampling after the start of the receiving time slot; Setting a dynamic range of the ADC, and determining a desired signal power threshold based on the dynamic range of the ADC; AGC control is performed based on the signal power estimation value, the dynamic range of the ADC and the expected signal power threshold, and the decibel of the digitally controlled attenuator is adjusted.

2. The method according to claim 1, characterized in that The calculating of the signal power estimation value after ADC sampling after the receiving time slot starts includes: Get the absolute value of the real part and the absolute value of the imaginary part of the ADC sampling value; Calculating the signal power estimation value based on formula (1); In formula (1), P cal Represents the signal power estimation value, N represents the number of sampling points, |RE i | represents the absolute value of the real part of the i-th ADC sampling value, |IM i | represents the absolute value of the imaginary part of the i-th ADC sampling value.

3. The method according to claim 2, characterized in that The determining of the expected signal power threshold based on the dynamic range of the ADC includes: Based on the dynamic range of the ADC, the lower limit of the desired signal power threshold is determined using formula (2); P′ low =0.5×[P low +P high ]-10; (2) In formula (2), P′ low Represents the lower limit of the desired signal power threshold, P low Represents the dynamic lower limit of the ADC, P high Indicates the dynamic upper limit value of the ADC; Based on the dynamic range of the ADC, determine the upper limit of the desired signal power threshold using formula (3); P′ high =0.5×[P low +P high ]+10; (3) In formula (3), P′ high Indicates the upper limit of the desired signal power threshold, P low Represents the dynamic lower limit of the ADC, P high Indicates the dynamic upper limit value of the ADC.

4. The method according to claim 3, characterized in that The AGC control is performed based on the signal power estimation value, the dynamic range of the ADC and the expected signal power threshold, and the decibel of the digitally controlled attenuator is adjusted, including: If P cal >P high -T, then the feedback gain control function is activated to increase the decibel of the digitally controlled attenuator; If P cal <P low +T, the feedback gain control function is activated to reduce the decibel of the digitally controlled attenuator; If P′ high <P cal ≤P high -T or P′ low >P cal ≥P low +T, the feedforward gain control function is started, the decibel of the digitally controlled attenuator is not adjusted, and power control is performed according to the relationship between the desired signal power threshold and the signal power estimation value; Among them, P cal Represents the signal power estimate, P high Indicates the dynamic upper limit of ADC, P low represents the dynamic lower limit of ADC, T represents the signal power protection value, P′ high Represents the upper limit of the desired signal power threshold, P′ low Indicates the lower limit of the expected signal power threshold.

5. The method according to claim 4, characterized in that The signal power protection value is 6 decibels.

6. The method according to claim 4, characterized in that The difference between the upper limit value of the expected signal power threshold and the lower limit value of the expected signal power threshold is 20 decibels.

7. The method according to claim 4, characterized in that The performing power control according to the relationship between the expected signal power threshold and the signal power estimation value comprises: If P cal >P′ high , then the signal power estimation value after ADC sampling is reduced, and the reduced value is P cal -P′ high ; If P cal <P′ low , then the signal power estimation value after ADC sampling is increased, and the increased value is P′ low -P cal ; If P′ low ≤P cal ≤P′ high , the signal power estimation value after ADC sampling remains unchanged.

8. An AGC control system, characterized in that: include: A digitally controlled attenuator, an ADC, a power detection and controller, and a digital gain generator connected in sequence; Wherein, the power detection and controller is also connected to the digitally controlled attenuator to realize feedback power control; The power detection and controller is also connected to the digital gain generator to implement feedforward power control.

Images