CN103841633B - A kind of TD LTE auto gain control methods and equipment - Google Patents

Abstract

The present invention provides a TD-LTE automatic gain control method, which takes the frame length as the unit in the frequency point scanning and the primary synchronization symbol SS detection stage, the secondary synchronization symbol SSS detection and the PBCH reading stage in the half frame length as the unit, the downlink In the receiving stage of the traffic channel, the average power of the corresponding symbols in each TD‑LTE frame is calculated in units of subframe length; the average power and the power upper limit and/or power lower limit, the first target power value, and the second target power are respectively passed. The comparison of power value, draws the most reasonable power gain control value of each stage; The present invention also provides a kind of TD-LTE automatic gain control equipment; The present invention distinguishes the environmental characteristics of three stages, has improved the flexibility of power control sex.

Description

A TD-LTE automatic gain control method and device

technical field

The present invention relates to long term evolution (LTE, Long Term evolution) wireless communication technology, in particular to a time division long term evolution (TD-LTE, Time Division Long Term Evolution) automatic gain control (AGC, Automatic Gain Control) method and equipment.

Background technique

LTE is the evolution of the third generation (3G, Third Generation) mobile communication system, due to the use of Orthogonal Frequency Division Multiplexing (OFDM, Orthogonal Frequency Division Multiplexing) technology and Multiple-Input Multiple-Output (MIMO, Multiple-Input Multiple-Out-put ) technology and other core technologies can be regarded as quasi-4G technologies. The LTE system can provide a peak rate of 100Mbps downlink and 50Mbps uplink under a 20MHz spectrum bandwidth, which can improve the performance of cell edge users and increase cell capacity.

At present, the LTE system includes TD-LTE and Frequency Division Duplexing Long Term Evolution (FDD-LTE, Frequency Division Duplexing Long Term evolution), because TD-LTE can use the same frequency point for data transmission in the uplink and downlink, which can save the frequency band resources, and are more favored by researchers.

In the TD-LTE system, a TD-LTE frame is 10ms, which can be divided into two half-frames of 5ms, and each half-frame of 5ms can be composed of five subframes of 1ms, and each subframe of 1ms has a unique identifier the frame number.

In the prior art, the TD-LTE downlink signal processing process includes the following three stages: frequency point scanning and primary synchronization symbol (PSS, Primary Synchronization Signal) detection stage, secondary synchronization symbol (SSS, Secondary Synchronization Signal) detection and Physical Broadcasting Channel (PBCH, Physical Broadcasting Channel) reading stage, downlink traffic channel receiving stage; among them, frequency point scanning is mainly used to scan and check the average value, maximum power value and minimum value of signal power in the main diversity antenna Interference signal, through the investigation of the interference signal, PSS detection determines the position of the PSS symbol in the TD-LTE half-frame length, and the UE can know the 5ms synchronization information at this time; SSS detection is used to determine the position of the SSS symbol in the frame length. At the same time, the UE can know the 10ms synchronization information, and at the same time, the PBCH can read the TD-LTE frame number synchronization information; the 5ms synchronization information, 10ms synchronization information and frame number synchronization information are aggregated into TD-LTE downlink synchronization information, frame synchronization The information enables the user equipment (UE, UserEquipment) to smoothly receive the signal sent by the base station through the downlink traffic channel.

In the above three stages, the signal sent by the base station will inevitably add interference when it is processed layer by layer, thereby weakening the signal strength. In order to ensure that the signal sent by the base station can reach the UE smoothly, all three stages will introduce A certain power control method. In the prior art, the usual method is to introduce the same power control method into each stage to ensure the stability of signal strength, but ignores the characteristics of the environment in which the signals in these three stages are located, then the same power control method It would be inflexible to apply to these three different stages, so there is an urgent need for a power control method that can be flexibly applied to these three stages.

Contents of the invention

In view of this, the main purpose of the present invention is to provide a TD-LTE automatic gain control method and equipment, which can solve the problem of inflexibility of power control methods in the prior art.

In order to achieve the above object, technical solution of the present invention is achieved in that way:

The present invention provides a kind of TD-LTE automatic gain control method, described method comprises:

In the frequency point scanning and primary synchronization symbol PSS detection phase, the frame length is used as the unit, the secondary synchronization symbol SSS detection and the physical broadcast channel PBCH reading phase are in the half frame length, and the downlink traffic channel receiving phase is in the subframe length. Calculate the average power of the corresponding symbols in each TD-LTE frame; respectively, by comparing the average power with the power upper limit and/or power lower limit, the first target power value, and the second target power value, the power of each stage is obtained. The most reasonable power gain control value.

In the above scheme, in the frequency point scanning and PSS detection stages, the method includes:

Calculate the average power value of each symbol of the current TD-LTE frame in units of 10ms frame length and determine the maximum average power value, compare the maximum average power value with the power upper limit and/or power lower limit, and output the current TD-LTE based on the comparison result From the power gain control value of the frame to the SSS detection and PBCH reading stage at this stage, or the processing of the next TD-LTE frame.

In the above scheme, in the SSS detection and PBCH reading stages, the method includes:

Receive power gain control value, calculate the average power value of the current half-frame PSS symbol and SSS symbol with the 5ms half-frame length of the TD-LTE frame as the unit, and compare the calculated current half-frame PSS symbol and SSS symbol average power value with the first target Compare the power values, update and output the power gain control value of the current half frame at this stage to the receiving stage of the downlink traffic channel according to the comparison result, and process the next half frame at the same time, or perform the processing of the next half frame.

In the above scheme, in the receiving phase of the downlink traffic channel, the method includes:

The receiving power gain control value, taking the 1ms subframe length of the TD-LTE frame as the unit, will calculate the average power value of the RS symbol of the current subframe, and compare the calculated average power value of the RS symbol of the current subframe with the second target power value Comparing, updating the power gain control value of the current subframe at this stage according to the comparison result and notifying the current user equipment UE, or performing the processing of the next subframe.

In the above scheme, the method includes:

Receive the power gain range indicated by the radio frequency chip, and divide the power gain range into multiple sub-sections to obtain the average power gain variation;

Update the initial power gain value of the first frame received by the current UE to the value of the minimum gain value, use the average power calculation method to calculate the average power value of each symbol within the length of the first frame, compare and find the maximum average power value , as the maximum average power value of the first frame;

When the maximum average power value of the first frame is greater than the power upper limit, update the initial power gain value of the first frame as the initial power gain value of the second frame;

When the maximum average power value of the first frame is less than the power upper limit and less than the power lower limit, the initial power gain value of the first frame is updated as the initial power gain value of the second frame;

When the maximum average power value of the first frame is less than the upper power limit and greater than the lower power limit, update the initial power gain value of the first frame as the initial power gain value of the second frame;

Outputting the maximum average power value of the first frame as the second frame power gain control value to the PSS detection and PBCH reading stages;

Using the average power calculation method, calculate the average power value of each symbol in the second frame length, compare and find the maximum average power value, as the maximum average power value of the second frame,

When the maximum average power value of the second frame is greater than the power upper limit, update the initial power gain value of the second frame as the initial power gain value of the third frame;

When the maximum average power value of the second frame is less than the power upper limit and less than the power lower limit, update the initial power gain value of the second frame as the initial power gain value of the third frame;

When the maximum average power value of the second frame is less than the upper power limit and greater than the lower power limit, update the initial power gain value of the second frame as the initial power gain value of the third frame;

Outputting the maximum average power value of the second frame as the second frame power gain control value to the PSS detection and PBCH reading stages;

By analogy, until all frames received by the UE are completed.

In the above scheme, the method includes:

Receive the power output control value sent by the current frame in the frequency point scanning and PSS detection phase, and use it as the initial power gain value of the first half frame of the current frame;

Calculate the average power of the first half-frame PSS symbol and SSS symbol in the frequency domain according to the average power calculation method, and filter through the loop filter circuit. At this time, the average power value is used as the first half-frame average power value of the current frame;

Judging whether the average power value of the first half frame is equal to the first target power value, when the average power value of the first half frame is equal to the first target power value, enter the second half frame processing of the current frame; when the average power value of the first half frame When the power value is not equal to the first target power value, update the average power gain value of the first half frame as the power gain control value of the current half frame, output to the receiving stage of the downlink traffic channel, and enter the second half frame of the current frame at the same time process;

Said entry processes the second half frame of the current frame as follows:

Calculate the average power of the second half-frame PSS symbol and SSS symbol in the frequency domain according to the average power calculation method, and filter through the loop filter circuit, and the average power value is now used as the second half-frame average power value;

Judging whether the average power value of the second half frame is equal to the first target power value, when the average power value of the second half frame is equal to the first target power value, enter the processing of the third half frame of the current frame; when the average power value of the second half frame When the power value is not equal to the first target power value, update the average power gain value of the second half frame as the power gain control value of the current half frame, output to the receiving stage of the downlink traffic channel, and enter the third half frame of the current frame at the same time process;

By analogy, until all half frames received by the UE are completed.

In the above scheme, the method includes:

The downlink traffic channel receiving stage receives the current half-frame power gain control value sent by the PSS detection and PBCH reading stage, and performs bandwidth-variable processing on the current half-frame power gain control value, and converts the processed current half-frame power The gain control value is used as the initial power gain value of the first subframe of the current half frame;

Calculate the average power of the first subframe RS symbol in the frequency domain according to the average power calculation method, and after filtering by the loop filter circuit, the average power value at this time is the average power value of the first subframe of the current half frame;

Compare whether the first subframe average power value is equal to the second target power value, and when the first subframe average power value is equal to the second target power value, enter the second subframe processing of the current half frame; when the first subframe When the average power value is not equal to the second target power value, update the average power gain value of the first subframe, and notify the current UE as the power gain control value of the current subframe; at the same time, enter the second subframe processing of the current half frame;

The entry processing of the second subframe of the current half frame is as follows:

Calculate the average power of the second subframe RS symbol in the frequency domain according to the average power calculation method, and after filtering by the loop filter circuit, the average power value at this time is the average power value of the second subframe of the current half frame;

Compare whether the average power value of the second subframe is equal to the second target power value, and when the average power value of the second subframe is equal to the second target power value, enter the third subframe processing of the current half frame; when the second subframe When the average power value is not equal to the second target power value, update the average power gain value of the second subframe, and notify the current UE as the power gain control value of the current subframe; at the same time, enter the third subframe processing of the current half frame;

By analogy, until all subframes received by the current UE are completed.

The present invention also provides a TD-LTE automatic gain control device, which includes: a first-stage power gain control module, a second-stage power gain control module, a third-stage power gain control module and a loop filter circuit; wherein ,

The first-stage power gain control module is used to calculate the average power value of each symbol in the current TD-LTE frame and determine the maximum average power value in units of 10ms frame length, and combine the maximum average power value with the power upper limit and/or power lower limit Compare and obtain the most reasonable power gain control value at this stage;

The second-stage power gain control module is used to calculate the average power value of the current half-frame PSS symbol and SSS symbol with the 5ms half-frame length of the TD-LTE frame as a unit, and calculate the current half-frame PSS symbol, The average power value of the SSS symbol is compared with the first target power value to obtain the most reasonable power gain control value at this stage;

The third-stage power gain control module is used to calculate the average power value of the RS symbol of the current subframe with the 1ms subframe length of the TD-LTE frame as the unit, and calculate the average power value of the RS symbol of the current subframe Compared with the second target power value, the most reasonable power gain control value at this stage is obtained;

The loop filter circuit is used to filter the average power value calculated by the power gain control module of the second stage and the power gain control module of the third stage.

In the above solution, the first stage power gain control module includes: a first processing submodule and a first update output submodule; wherein,

The first processing submodule is used to calculate the average power value of each symbol in the current TD-LTE frame with a frame length of 10 ms as a unit, and compare the average power value of each symbol in the current TD-LTE frame to determine the maximum average power of the current frame value, compare the maximum average power value of the current frame with the power upper limit and/or power lower limit;

The first update output submodule is used to update the current TD-LTE frame power gain control value as the initial power gain value of the next frame and send it to the first processing submodule, or output the current TD-LTE frame power gain control value according to the comparison result. The LTE frame power gain control value is sent to the second stage power gain control module as the power gain control value of the current frame in the first stage power gain control module;

The first processing submodule is further configured to start processing the next frame after receiving the initial power gain value of the next frame from the first update output submodule.

In the above solution, the second stage power gain control module includes: a second processing submodule and a second update output submodule;

The second processing submodule is used to calculate the average power value of the current half-frame PSS symbol and SSS symbol in units of 5ms frame length; and compare the calculated current half-frame PSS symbol and SSS symbol average power value with the first target Power value size;

The second update output submodule is used to update the power gain value of the current half frame and output it to the power gain control module of the third stage according to the comparison result, and at the same time notify the second processing submodule to process the next half frame, Or notify the second processing submodule to process the next field;

The second processing submodule is further configured to start processing the next half frame after receiving the notification sent by the second update output submodule.

In the above solution, the third stage power gain control module includes: a third processing submodule and a third update output submodule; wherein,

The third processing submodule is used to calculate the average power value of the reference signal RS symbol of the current subframe, and compare the calculated average power value of the RS symbol of the current subframe with the second target power value;

The third update output submodule is used to update the power gain control value of the current subframe according to the comparison result, and notify the current UE, and at the same time notify the third processing submodule to process the next subframe, or notify the The third processing submodule performs next subframe processing;

The third processing submodule is further configured to start processing the next subframe after receiving the notification sent by the third update output submodule.

The TD-LTE automatic gain control method and equipment provided by the present invention are aimed at the environmental characteristics of the three stages included in the TD-LTE downlink signal processing process, taking frame length, half frame length, and subframe length as units respectively, for Calculate the average power of the corresponding symbols in each TD-LTE frame, and compare the average power with the power upper limit and/or power lower limit, the first target power value, and the second target power value to obtain the The most reasonable power gain control value; the invention distinguishes the environmental characteristics of the three stages included in the TD-LTE downlink signal processing process, and increases the flexibility of power control.

Description of drawings

Fig. 1 is the realization flow diagram of TD-LTE automatic gain control method of the present invention;

Fig. 2 is the realization flow diagram of TD-LTE automatic gain control method of the present invention in frequency scanning and PSS detection stage;

Fig. 3 is the realization flow diagram of TD-LTE automatic gain control method of the present invention in SSS detection and PBCH reading stage;

Fig. 4 realizes the schematic flow chart of the TD-LTE automatic gain control method of the present invention in the downlink traffic channel receiving stage;

FIG. 5 is a schematic diagram of the composition and structure of a TD-LTE automatic gain control device according to the present invention.

detailed description

TD-LTE automatic gain control method provided by the present invention, described method comprises:

In the frequency point scanning and PSS detection stage, the frame length is used as the unit, the SSS detection and PBCH reading stage is used as the half frame length, and the downlink service channel receiving stage is subframe length, and the corresponding symbol in each TD-LTE frame is The average power is calculated; the most reasonable power gain control value for each stage is obtained by comparing the average power with the power upper limit and/or power lower limit, the first target power value, and the second target power value respectively.

Here, the frequency point scanning and PSS detection stages calculate the average power of each symbol in each TD-LTE frame; the SSS detection and PBCH reading stages calculate the PSS symbols and SSS symbols in each TD-LTE half frame. Average power: The average power of RS symbols in each TD-LTE subframe is calculated in the receiving phase of downlink traffic channels.

As shown in Figure 1, the method specifically includes step 10, step 20 and step 30:

Step 10: Calculate the average power value of each symbol of the current TD-LTE frame in units of 10ms frame length and determine the maximum average power value, and compare the calculated maximum average power value with the power upper limit and/or power lower limit, based on the comparison The result outputs the power gain control value of the current TD-LTE frame at this stage to the SSS detection and PBCH reading stage, or proceeds to the next TD-LTE frame processing;

Here, for the environmental characteristics of the frequency point scanning and PSS detection stages, the unit of frame length is 10ms;

Specifically, since the current UE has not obtained any synchronization information for the frequency point scanning and PSS detection phases, within a TD-LTE frame length of 10ms, the uplink and downlink signals in the entire cell may be blocked The current UE is used as an average power estimate. Then, according to the environmental characteristics of this stage, a statistical AGC method can be used to obtain better power gain control.

Currently, the UE receives radio frequency circuit signals, and the radio frequency circuit includes a power amplifier, an analog-to-digital converter (ADC, Analog Digital Conversion), a radio frequency chip, etc.; wherein, the radio frequency chip manufacturer has marked the radio frequency chip when the radio frequency chip leaves the factory Applicable power gain range: from the minimum gain value G_min to the maximum gain value G_max; the power gain range varies with different models of radio frequency chips, and also varies with different manufacturers.

As shown in Figure 2, the specific process of step 10 can be:

Divide the power gain range M indicated by the radio frequency chip into N subsections on average, and the average power gain of each subsection is M/N(db), and M/N(db) is used as the average power gain variation, where N is a positive integer;

Here, assuming that the number of all TD-LTE frames received by the current UE is i, and i is a positive integer, then all the received TD-LTE frames can be arranged as the first frame, the second frame ... the first frame i frame;

The first frame is processed first, and the initial power gain value A_G(1) of the first frame is updated to be the value of the minimum gain value G_min;

Substituting the first frame power gain initial value A_G(1) into the average power value calculation method in the prior art to calculate the average power value of each symbol in the first frame length;

Comparing the average power value of each symbol within the length of the first frame, and finding the maximum average power value as the maximum average power value of the first frame;

Compare the maximum average power value of the first frame with the power upper limit P _maxlim , when the maximum average power value of the first frame is greater than the power upper limit P _maxlim , update the initial power gain value of the first frame A_G(2)=A_G(1)+M /N, as the initial power gain value of the second frame, enter the second frame processing; when the maximum average power value of the first frame is less than the power upper limit P _maxlim , then compare the maximum average power value of the first frame with the power lower limit P _minlim ;

When the first frame maximum average power value is less than the power lower limit _Pminlim , update the first frame initial power gain value A_G(2)=A_G(1)-M/N, as the second frame initial power gain value, enter the second Frame processing; when the maximum average power value of the first frame is greater than the power lower limit P _minlim , output the initial power gain value A_G(1) of the first frame to the SSS detection and PBCH reading stages, as the first frame in frequency point scanning and PSS detection The power gain control value result1 of stage output;

The entry into the processing of the second frame may specifically be:

Substituting the second frame power gain initial value A_G(2) into the average power value calculation method in the prior art to calculate the average power value of each symbol in the second frame length;

Comparing the average power value of each symbol within the length of the second frame and finding the maximum average power value as the maximum average power value of the second frame;

Compare the maximum average power value of the second frame with the size of the power upper limit P _maxlim , when the maximum average power value of the second frame is greater than the power upper limit P _maxlim , update the initial power gain value of the second frame A_G(3)=A_G(2)+M /N, as the initial power gain value of the third frame, enter the processing of the third frame; when the maximum average power value of the second frame is less than the power upper limit P _maxlim , then compare the second frame maximum average power value with the power lower limit P _minlim ;

When the second frame maximum average power value is less than the power lower limit _Pminlim , update the second frame initial power gain value A_G(3)=A_G(2)-M/N, as the third frame initial power gain value, enter the third frame Frame processing; when the second frame maximum average power value is greater than the power lower limit _Pminlim , output the second frame initial power gain value A_G(2), as the power gain control value result1 of the second frame output in the frequency point scanning and PSS detection stages ;

The specific process of processing the third frame by the entry is similar to the implementation process of processing the second frame by the entry, and so on until all frames received by the current UE are processed.

In step 10, the power upper limit P _maxlim and the power lower limit P _minlim are pre-set; for different frames, the power upper limit P _maxlim and the power lower limit P _minlim can take the same value or different values;

Among them, the value range of the power upper limit P _maxlim is 10log10(2 ^m )+15(db), the value range of the power lower limit P _minlim is 10log10(2 ^m )-15(db), m is the bit width of the ADC device; ADC The bit width of the device has been marked with the bit width range when the ADC device leaves the factory.

In addition, the parameter N ranges from 3 to 6, which can be flexibly adjusted according to the actual environment (such as field testing); when the actual environment requires faster convergence and the gain accuracy range is not high, N can be taken as a smaller value; Conversely, N can be taken as a relatively large value; since this stage is processing the frame, after calculating the average power value of each symbol in each frame length, there is no need to go through the loop filter circuit for filtering processing at this stage.

It has been explained above that after the frequency point scanning and PSS detection phase is over, the position of the PSS symbol in the TD-LTE half-frame length can be determined, that is, the half-frame synchronization is determined, that is, the current UE already knows the 5ms synchronization information at this time, During the SSS detection and PBCH reading phase, the 5ms synchronization information will be fully utilized for automatic gain control during the SSS detection and PBCH reading phase.

Step 20: Receive the power gain control value, calculate the current half-frame PSS symbol and SSS symbol average power value in units of 5 ms half-frame length of the TD-LTE frame, and calculate the current half-frame PSS symbol and SSS symbol average power value with Comparing the first target power value, updating and outputting the power gain control value of the current half frame at this stage to the receiving stage of the downlink traffic channel according to the comparison result, and performing the processing of the next half frame at the same time, or performing the processing of the next half frame;

Here, for the environmental characteristics of the PSS detection and PBCH reading phases, the 5ms half-frame length of the TD-LTE frame is used as the unit;

It can be seen from the above scheme that the frequency point scanning and PSS detection phases are processed for a TD-LTE frame of 10 ms. After the frequency point scanning and PSS detection phases are completed, the current UE already knows 5 ms synchronization information, that is, half-frame synchronization information , the signal time window of the PSS symbol is determined; then, in the SSS detection, the signal time window of the SSS symbol can be determined;

Here, the signal time windows of PSS symbols and SSS symbols can be regarded as two points on the time coordinate axis, that is, the positions of PSS symbols and SSS symbols in the TD-LTE half-frame length have been determined, and the half-frame length can be PSS symbols and SSS symbols are extracted; it can be seen that this stage is mainly for TD-LTE half-frame length processing; here, the current 10ms TD-LTE frame is divided into the first half-frame and the second half-frame, Both the first half frame and the second half frame have a frame length of 5 ms.

As shown in Figure 3, the concrete processing procedure of step 20 can be:

Receive the result1 output from the frequency point scanning and PSS detection stages as the initial power gain value of this stage;

For the TD-LTE system, first use result1 as the initial power gain value of the first subframe at this stage, and after extracting the PSS symbols and SSS symbols of the first half frame of the current 10ms TD-LTE frame, use the existing technology to calculate the first half The average power of the frame PSS symbol and SSS symbol in the frequency domain is accumulated and averaged multiple times, and then filtered by the loop filter circuit to filter out noise, and the obtained result is the average power value p1 of the first half frame;

Judging whether the average power value p1 of the first half frame is equal to the first target power value Target, when p1 is equal to Target, use result1 as the initial power gain value of the second half frame, and enter the second half frame of the TD-LTE frame for the current t0ms processing; when p1 is not equal to Target, update the power gain control value result2=result1+(Target-p1) of the first half frame at this stage, and output result2 to the downlink traffic channel receiving stage, with result2 as the second half frame initial The power gain value enters the processing of the second half frame of the current 10ms TD-LTE frame;

The processing of entering the second half frame of the TD-LTE frame of the current 10 ms is specifically: extracting the PSS symbol and the SSS symbol of the second half frame of the TD-LTE frame of the current 10 ms, and calculating the average value of the second half frame using the prior art Power value p2; Then, judge whether the average power value p2 of the second half frame is equal to the target power value Target, when p2 is equal to Target, enter the first half frame of the next TD-LTE frame; when p2 is not equal to Target, update In the second half frame, the power gain control value result 2=p_old+(Target-p2) at this stage and output result 2 to the downlink traffic channel receiving stage;

Here, when the condition "p1 is not equal to Target" is established until now, p_old=result2 is taken; when the condition "p1 is equal to Target" is established until now, p_old=result1 is taken;

By analogy, until all half-frames received by the current UE are processed.

Here, the value of the first target power value Target should be designed according to the bit width m of the ADC device actually selected in the TD-LTE system, and the risk of saturation in the case of large noise/interference, usually Target=2 ^m .

At the same time, since this stage is for TD-LTE half-frame processing, the half-frame time is relatively short, and in the loop filter circuit, a relatively large loop filter coefficient needs to be set in advance to ensure fast convergence of half-frame symbols.

Under this description, when describing the technical solution of the present invention, whenever the loop filter coefficient is involved, the value range of the loop filter coefficient is 0.04-0.5.

In addition, when describing step 20, the TD-LTE system with 1.4M bandwidth is mainly used as an example. The technical solution of the present invention includes but is not limited to the TD-LTE system with 1.4M bandwidth, and can also be applied to TD-LTE with other bandwidths Systems, such as TD-LTE systems with 10M, 15M, and 20M bandwidth.

Step 30: receive the power gain control value, calculate the average power value of the RS symbol of the current subframe in units of 1 ms subframe length of the TD-LTE frame, and compare the calculated average power value of the RS symbol of the current subframe with the second target power value Make a comparison, update the power gain control value of the current subframe at this stage according to the comparison result, and notify the current UE, or perform the next subframe processing;

Here, for the environmental characteristics of the downlink traffic channel receiving stage, the unit of 1ms subframe length of the TD-LTE frame is used;

For the downlink service channel receiving stage, the current UE already knows the TD-LTE downlink synchronization information such as 5ms synchronization information, 10ms synchronization information and frame number synchronization information, that is, the current UE can determine each 1ms sub-frame through downlink synchronization. The position of the reference signal (RS, Referenc Signal) symbol in the frame in each subframe, then the RS in each subframe can be extracted; it can be seen that this stage is mainly for each 1ms of TD-LTE Subframe processing;

Here, the current 5 ms TD-LTE half frame is divided into a first subframe, a second subframe, a third subframe, a fourth subframe, and a fifth subframe, and each subframe is 1 ms long.

Due to the difference in bandwidth between the SSS detection and PBCH reading stage and this stage, this stage takes the TD-LTE system with 20M bandwidth as an example, because the power and bandwidth are proportional, that is, as the bandwidth increases, the power also increases. Enhanced accordingly. In order to achieve a better connection between the SSS detection and PBCH reading stages and this stage, here, the power gain control value result2 sent in the SSS detection and PBCH reading stages needs to be processed with variable bandwidth first.

As shown in Figure 4, the concrete processing procedure of step 30 can be:

The power gain control value result2 sent during the SSS detection and PBCH reading phases is subjected to variable bandwidth processing as shown in formula (1):

result2_new=result2-10*log10(B _new /B _old )(1)

Among them, the variable B _old is the TD-LTE system bandwidth used in the SSS detection and PBCH reading stages; B _new is the TD-LTE system bandwidth used in this stage.

Read result2_new as the initial power gain value of the first subframe in this stage;

After extracting the RS symbol of the first subframe of the TD-LTE half frame of the current 5 ms, the average power of the RS symbol of the first subframe of the current half frame in the frequency domain is calculated by using the existing technology, and the loop filter is performed by using the loop filter circuit, In order to filter out noise, the obtained result is the average power value M_p1 of the first subframe;

Judging whether the first subframe average power value M_p1 is equal to the second target power value Tar, when M_p1 is equal to Tar, use result2_new as the initial power gain value of the second subframe, and process the second subframe; when M_p1 is not equal to Tar , update the power gain control value result3=result2_new+(Tar-M_p1) of the first subframe at this stage, and notify the current UE of the value of result3, take result3 as the initial power gain value of the second subframe, and use result3 for the second subframe process;

Wherein, the processing of the second subframe may specifically be: extracting the RS symbol of the second subframe of the TD-LTE half frame of the current 5 ms, and calculating the average power of the RS symbol of the second subframe in the frequency domain by using the existing technology , using a loop filter circuit to perform loop filtering in order to filter out noise, and the obtained result is the second subframe average power value M_p2;

Judging whether the second subframe average power value M_p2 is equal to the second target power value Tar, when M_p2 is equal to Tar, use result2_new as the initial power gain value of the second subframe, and process the third subframe; when M_p2 is not equal to Tar , update the power gain control value result3=Y+(Tar-M_p2) of the second subframe at this stage, and notify the current UE of the value of result3, and use result3 as the initial power gain value of the third subframe to perform deal with;

Here, Y=result2_new when the condition “M_p1 is equal to Tar” is established until now; when the condition “M_p1 is not equal to Tar” is established and executed, Y=result3;

By analogy, until each subframe received by the current UE is processed.

In step 30, the second target power value Tar is designed according to the bit width m of the ADC device actually selected in the TD-LTE system, usually Target=2m, and the bit width m of the ADC device has been marked at the factory.

Considering the high control frequency required at this stage, in the loop filter circuit, it is necessary to select a smaller loop filter coefficient to ensure the stability of the downlink.

Based on the above TD-LTE automatic gain control method. The present invention also provides a TD-LTE automatic gain control device, as shown in Figure 5, the device includes: a first-stage power gain control module 50, a second-stage power gain control module 51, a third-stage power gain control module Module 52 and loop filter circuit 53; Wherein,

The first-stage power gain control module 50 is used to calculate the average power value of each symbol in the current TD-LTE frame and determine the maximum average power value in units of 10ms frame length, and combine the maximum average power value with the power upper limit and/or power The lower limit is compared to obtain the most reasonable power gain control value at this stage;

The second-stage power gain control module 51 is used to calculate the average power value of the current half-frame PSS symbol and SSS symbol with the 5ms half-frame length of the TD-LTE frame as a unit, and calculate the current half-frame PSS symbol , The average power value of the SSS symbol is compared with the first target power value to obtain the most reasonable power gain control value at this stage;

The third stage power gain control module 52 is used to calculate the average power value of the RS symbol of the current subframe with the 1ms subframe length of the TD-LTE frame as the unit, and calculate the average power value of the RS symbol of the current subframe Value is compared with the second target power value to obtain the most reasonable power gain control value at this stage;

The loop filter circuit 53 is configured to filter the average power value calculated by the power gain control module 51 of the second stage and the power gain control module 52 of the third stage.

Here, the first stage is the frequency point scanning and PSS detection stage, the second stage is the SSS detection and PBCH reading stage, and the third stage is the downlink traffic channel receiving stage.

Specifically, the first-stage power gain control module 50 receives the power gain range M indicated by the radio frequency chip, and divides M into N subsections on average, and uses M/N (db) as the average power gain variation; then update The initial power gain value of the first frame currently received by the UE is the value of the minimum gain value. Using the average power calculation method in the prior art, calculate the average power value of each symbol in the first frame length, compare and find the maximum The average power value of is used as the maximum average power value of the first frame;

When the maximum average power value of the first frame is greater than the power upper limit, the initial power gain value of the first frame is updated as the initial power gain value of the second frame;

When the maximum average power value of the first frame is less than the power upper limit and less than the power lower limit, the initial power gain value of the first frame is updated as the initial power gain value of the second frame;

When the maximum average power value of the first frame is less than the power upper limit and greater than the power lower limit, update the initial power gain value of the first frame as the initial power gain value of the second frame; at the same time, the initial power gain value of the first frame is used as the current frame power gain control value output to the second stage power gain control module 51;

According to the above technical solution, the first-stage power gain control module 50 processes the second frame received by the current UE until all received frames are completed.

Here, the power gain range and the minimum gain value have been marked values when the radio frequency chip leaves the factory.

The second stage power gain control module 51 receives the current frame power output control value sent by the first stage power gain control module 50 as the initial power gain value of the first half frame of the current frame;

According to the average power calculation method in the prior art, the second-stage power gain control module 51 can calculate the average power of the first half-frame PSS symbol and SSS symbol of the current frame in the frequency domain, and then the second-stage power gain control module 51 sends the calculated average power to the loop filter circuit 53, after filtering by the loop filter circuit 53, it returns to the second stage power gain control module 51, and the average power value returned at this time is the first Half frame average power value;

The second-stage power gain control module 51 receives and judges whether the first half-frame average power value is equal to the first target power value;

When the first half-frame average power value is equal to the first target power value, the second power gain control module 51 uses the current frame power output control value sent by the first-stage power gain control module 50 as the second half The frame initial power gain value starts to process the second half frame of the current frame according to the above technical solution;

When the first half-frame average power value is not equal to the first target power value, the second-stage power gain control module 51 updates the first half-frame average power gain value as the current half-frame power gain control value and outputs it to all The third stage power control module 52; at the same time, use the updated average power gain value of the first half frame as the initial power gain value of the second half frame, and start processing the second half frame of the current frame according to the above technical solution;

According to the above technical solution, the second stage power gain control module 51 processes the second half frame of the current frame until all half frames received by the current UE are processed.

The third-stage power gain control module 52 receives the current half-frame power gain control value sent by the second-stage power gain control module 51, and uses formula (1) to change the bandwidth of the current half-frame power gain control value Processing, using the processed power gain control value of the current half frame as the initial power gain value of the first subframe of the current half frame;

According to the average power calculation method in the prior art, the third-stage power gain control module 52 calculates the average power of the first subframe RS symbol in the frequency domain, and sends the calculated average power to the loop filter circuit 53, by After the loop filtering circuit 53 performs filtering, it returns to the third-stage power gain control module 52, and the average power value returned at this time is the average power value of the first subframe;

comparing whether the first subframe average power value is equal to the second target power value;

When the average power value of the first subframe is equal to the second target power value, the initial power gain value of the first subframe is used as the initial power gain value of the second frame, and the power gain control module 52 of the third stage starts according to the above technical solution Processing the second subframe of the current half frame;

When the first subframe average power value is not equal to the second target power value, the third stage power gain control module 52 updates the first subframe average power gain value as the current subframe power gain control value and notifies the current UE; at the same time, use the updated average power gain value of the first subframe as the initial power gain value of the second frame, and start processing the second subframe of the current half frame according to the above technical solution;

According to the above technical solution, the third stage power gain control module 52 processes the second subframe of the current half frame until all subframes received by the current UE are processed.

The first stage power gain control module 50 further includes a first processing submodule 500 and a first update output submodule 501; wherein,

The first processing submodule 500 is used to calculate the average power value of each symbol in the current TD-LTE frame with a frame length of 10 ms as a unit, and compare the average power value of each symbol in the current TD-LTE frame to determine the maximum average power value of the current frame. Power value, compare the maximum average power value of the current frame with the power upper limit and/or power lower limit;

The first update output submodule 501 is used to update the current TD-LTE frame power gain control value according to the comparison result, as the initial power gain value of the next frame and send it to the first processing submodule 500, or output the current The TD-LTE frame initial power gain value is sent to the second stage power gain control module 51 as the current TD-LTE power gain control value;

The first processing submodule 500 is further configured to start processing the next frame after receiving the initial power gain value of the next frame from the first update output submodule 501;

The second stage power gain control module 51 further includes a second processing submodule 510 and a second update output submodule 511;

The second processing submodule 510 is used to calculate the average power value of the current half-frame PSS symbol and SSS symbol with a frame length of 5 ms; and compare the calculated current half-frame PSS symbol and SSS symbol average power value with the first target power value;

The second update output submodule 511 is configured to update and output the current half-frame power gain value to the third-stage power gain control module 52 according to the comparison result, and at the same time notify the second processing submodule 510 to proceed to the next half frame Frame processing; or only notify the second processing submodule 510 to process the next half frame;

The second processing submodule 510 is further configured to start processing the next field after receiving the notification sent by the second update output submodule 511 .

The third stage power gain control module 52 further includes a third processing submodule 520 and a third update output submodule 521; wherein,

The third processing submodule 520 is used to calculate the average power value of the RS symbol of the current subframe after calculating the variable bandwidth, and compare the calculated average power value of the RS symbol of the current subframe with the second target power value;

The third update output submodule 521 is used to update the power gain control value of the current subframe according to the comparison result, and notify the current UE, and at the same time notify the third processing submodule 520 to process the next subframe; or only notify The third processing submodule 520 performs next subframe processing;

The third processing submodule 520 is further configured to start processing the next subframe after receiving the notification sent by the third update output submodule 521 .

Specifically, when the current UE is in the phase of frequency point scanning and PSS detection, first, the first processing submodule 500 receives the power gain range M marked by the radio frequency chip, and divides M into N subsections on average, then, M /N(db) is the average power gain of each sub-section;

Here, M/N (db) is used as the average power gain variation, where N is a positive integer; when the radio frequency chip leaves the factory, the minimum gain value G_min and the maximum gain value G_max are marked;

Arrange the numbers of all frames received by the current UE in order, which are the first frame, the second frame...the i-th frame, where i is a positive integer;

The first processing sub-module 500 first processes the first frame, and updates the initial power gain value A_G(1) of the first frame to the value of the minimum gain value G_min;

Using the average power calculation method in the prior art, the first processing submodule 500 calculates the average power value of each symbol in the first frame length; and compares the average power value of each symbol in the first frame length and finds out The maximum average power value, as the maximum average power value of the first frame;

When the maximum average power value of the first frame is greater than the power upper limit P _maxlim , the first update output submodule 501 updates the initial power gain value A_G(2)=A_G(1)+M/N of the first frame as the second frame Initial power gain value, the first update output submodule 501 outputs A_G(2) at this time to the first processing submodule 500;

When the maximum average power value of the first frame is less than the power upper limit P _maxlim , the first processing submodule 500 then compares the maximum average power value of the first frame with the power lower limit P _minlim ,

When the maximum average power value of the first frame is less than the lower power limit _Pminlim , the first update output submodule 501 updates the initial power gain value A_G(2)=A_G(1)-M/N of the first frame as the second frame Initial power gain value, the first update output submodule 501 outputs A_G(2) at this time to the first processing submodule 500;

When the maximum average power value of the first frame is greater than the power lower limit _Pminlim , the first update output submodule 501 outputs the A_G(1) value and sends it to the second stage power gain control module 51, specifically to the second The processing sub-module 510 is used as the power gain control value result1 output in the frequency point scanning and PSS detection stages of the first frame;

After the first processing submodule 500 receives A_G(2), using the average power calculation method in the prior art, the first processing submodule 500 calculates the average power value of each symbol within the second frame length; and Comparing the average power value of each symbol within the length of the second frame and finding the maximum average power value as the maximum average power value of the second frame;

When the second frame maximum average power value is greater than the power upper limit _Pmaxlim , the first update output submodule 501 updates the second frame initial power gain value A_G(3)=A_G(2)+M/N as the third frame Initial power gain value, the first update output submodule 501 outputs A_G(3) at this time to the first processing submodule 500;

When the maximum average power value of the second frame is less than the power upper limit P _maxlim , the first processing submodule 500 then compares the maximum average power value of the second frame with the power lower limit P _minlim ,

When the maximum average power value of the second frame is less than the power lower limit _Pminlim , the first update output submodule 501 updates the initial power gain value A_G(3)=A_G(2)-M/N of the second frame as the third frame Initial power gain value, the first update output submodule 501 outputs A_G(3) at this time to the first processing submodule 500;

When the maximum average power value of the first frame is greater than the power lower limit _Pminlim , the first update output submodule 501 outputs the A_G(2) value and sends it to the second stage power gain control module 51, specifically to the second The processing sub-module 510 is used as the power gain control value result1 output by the power gain control module 50 in the first stage in the second frame;

According to the above technical solution, after the first processing submodule 500 receives A_G(3), it combines with the first update output submodule 501 to complete the processing of the third frame, and so on until the current UE receives all frame processing.

Here, the power upper limit P _maxlim and the power lower limit P _minlim are preset in the first-stage power gain control module 50, specifically in the first processing sub-module 500; for different frames, The power upper limit P _maxlim and the power lower limit P _{minlim may} take the same value or different values;

Among them, the value range of the power upper limit P _maxlim is 10log10(2 ^m )+15(db), the value range of the power lower limit P _minlim is 10log10(2 ^m )-15(db), m is the bit of the ADC device in the radio frequency circuit wide; the signal sent by the radio frequency circuit is received by the current UE;

In addition, the value range of the parameter N is 3-6, which is preset in the power gain control module 50 of the first stage, specifically in the first processing sub-module 500; because this stage is for frame processing, so after the first processing submodule 500 calculates the average power value of each symbol in each frame length, it is not necessary to send the calculated average power value of each symbol to the loop filter circuit 53 for filtering deal with.

When the current UE is in the phase of PSS detection and PBCH reading, the second processing submodule 510 receives the result1 sent by the power gain control module 50 of the first phase as the initial power gain value;

At this stage, the current UE can know the synchronization information of 5 ms, so the power gain control module 51 in the second stage can determine the position of the PSS symbol and SSS symbol in each half frame, and then can extract and calculate the PSS symbol in each half frame symbol, SSS symbol average power value;

Taking a TD-LTE frame received by the current UE as an example, the TD-LTE frame can be divided into the first half frame and the second half frame;

The second processing sub-module 510 receives the result1 sent by the power gain control module 50 of the first stage as the initial power gain value of the first half frame, and calculates the first half frame by substituting result1 into the average power calculation method of the prior art. The average power of the frame PSS symbol and SSS symbol in the frequency domain, and then the second processing submodule 510 sends the calculated average power to the loop filter circuit 53, after filtering by the loop filter circuit 53, then return the average power to the second processing sub-module 510, and return the average power value at this time to the first half-frame average power value p1;

The second processing submodule 510 judges whether the first half-frame average power value p1 is equal to the first target power value Target,

When p1 is equal to Target, using result1 as the initial power gain value of the second half frame, the second processing submodule 510 starts processing the second half frame;

When p1 is not equal to Target, the second update output submodule 511 updates the first half-frame power gain control value result2, and outputs result2 to the third stage power control module 52, specifically to the third processing submodule 520: Using result2 as the initial power gain value of the second half frame, the second update output submodule 511 notifies the second processing submodule 510 to start processing the second half frame;

Among them, result2=result1+(Target-p1);

After the second processing sub-module 510 receives the notification (result2 is used as the initial power gain value of the second half frame) or recognizes (result1 is used as the initial power gain value of the second half frame) that the next half frame needs to be processed, it starts to process the The second half frame is processed: the second half frame initial power gain value is substituted into the average power calculation method of the prior art to calculate the second half frame PSS symbol, the average power of the SSS symbol in the frequency domain, and then the second processing sub Module 510 sends the calculated average power to the loop filter circuit 53, after filtering by the loop filter circuit 53, the average power is returned to the second processing sub-module 510, and the average power returned at this time is The second half-frame average power value p2;

The second processing submodule 510 judges whether the second half-frame average power value p1 is equal to the first target power value Target,

When p2 is equal to Target, the second half-frame initial power gain value is used as the third half-frame initial power gain value, and the second processing submodule 510 starts processing the third half-frame;

When p2 is not equal to Target, the second update output submodule 511 updates the first half-frame power gain control value result2, result2=p_old+(Target-p1), and outputs result2 to the third stage power gain control module 52, specifically output to the third processing sub-module 520; the second update output sub-module 511 notifies the second processing sub-module 510 to start processing the first field of the next frame;

Among them, when the condition of "p1 is not equal to Target" is established until now, p_old=result2 is taken; when the condition of "p1 is equal to Target" is established until now, p_old=result1 is taken;

According to the above technical solution, after the second processing sub-module 510 receives the notification or recognizes that the first half frame of the next frame needs to be performed, it combines with the second update output sub-module 511 to complete the first field of the next frame. The processing is performed on half a frame; until all half frames received by the current UE are processed.

Here, the first target power value Target is preset in the second stage power gain control module 51 , specifically in the second processing submodule 510 .

When the current UE is in the receiving stage of the downlink traffic channel, the current UE can know 5ms synchronization information, 10ms synchronization information and frame number synchronization information, so the third stage power gain control module 52 can determine the RS symbol in each subframe Position, and then can extract and calculate the average power value of each subframe RS symbol;

Taking a TD-LTE half frame currently received by the UE as an example, the TD-LTE half frame can be divided into the first subframe, the second subframe, the third subframe, the fourth subframe, and the fifth subframe ;

Because the operating bandwidths of the second-stage power gain control module 51 and the third-stage power gain control module 52 are different, the third processing sub-module 520 receives the second-stage power gain After controlling the power gain control value result2 of the control module 51, first perform variable bandwidth processing according to formula (1), and then read result2_new after the variable bandwidth processing has been completed as the initial power gain value of the first subframe;

The third processing submodule 520 substitutes result2_new into the average power calculation method of the prior art to calculate the average power of the first subframe RS symbol in the frequency domain, and then the third processing submodule 520 sends the calculated average power to the loop filter circuit 53, after filtering by the loop filter circuit 53, return the average power to the third processing sub-module 520, and return the average power value at this time to the first subframe average power value M_p1 ;

Next, the third processing submodule 520 judges whether the first subframe average power value M_p1 is equal to the second target power value Tar,

When M_p1 is equal to Tar, take result2_new as the initial power gain value of the second subframe, and the third processing submodule 520 starts processing the second subframe;

When M_p1 is not equal to Tar, the third update output submodule 521 updates the first subframe power gain control value result3=result2_new+(Tar-M_p1), and notifies the current UE of result3; takes result3 as the second half frame initial For a power gain value, the third update output submodule 521 notifies the third processing submodule 520 to start processing the second subframe;

The third processing sub-module 520 receives the notification (use result3 as the initial power gain value of the second half frame) or recognizes itself (uses result2_new as the initial power gain value of the second half frame) that it needs to perform the next subframe processing , starting to process the second subframe in conjunction with the third update output submodule pair 521:

The third processing submodule 520 calculates the average power of the RS symbols in the frequency domain of the second subframe according to the average power calculation method in the prior art, and then the third processing submodule 520 sends the calculated average power to the The loop filter circuit 53, after filtering by the loop filter circuit 53, returns the average power to the third processing sub-module 520, and returns the average power value at this time to the second subframe average power value M_p1;

Next, the third processing submodule 520 judges whether the second subframe average power value M_p2 is equal to the second target power value Tar,

When M_p2 is equal to Tar, take result2_new as the initial power gain value of the third subframe, and the third processing submodule 520 starts to process the third subframe;

When M_p2 is not equal to Tar, the third update output submodule 521 updates the second subframe power gain control value result3=Y+(Tar-M_p2), and notifies the current UE of result3; the third update output submodule 521 Notify the third processing submodule 520 to start processing the third subframe;

Here, Y=result2_new when the condition “M_p1 is equal to Tar” is established and executed until now; when the condition “M_p1 is not equal to Tar” is established and executed until now 1, Y=result3;

According to the above technical solution, after receiving the notification, the third processing submodule 520 combines with the second update output submodule 521 to complete the processing of the next subframe; until all subframes received by the current UE are processed. frame.

Here, the second target power value Tar is preset in the power gain control module 52 of the third stage, specifically in the third processing sub-module 520;

At this stage, the current UE already knows TD-LTE downlink synchronization information such as 5ms synchronization information, 10ms synchronization information and frame number synchronization information, that is to say, through downlink synchronization, the third processing submodule 520 can determine each The position of the reference signal RS (Referenc Signal) symbol in the 1ms subframe in each subframe, then the RS in each subframe can be extracted.

The TD-LTE terminal automatic gain control method and equipment provided by the present invention are applicable to TD-LTE systems with bandwidths of 1.4M, 3M, 5M, 10M, 15M and 20M.

The TD-LTE automatic gain control method provided by the present invention, aiming at the environmental characteristics of the three stages, takes the frame length as the unit, the half-frame length as the unit, and the sub-frame length as the unit to calculate the average power of the corresponding symbol, by Comparing the maximum average power value of a frame-long symbol with the power upper limit and/or power lower limit, the most reasonable power gain control value in the frequency point scanning and PSS detection stages can be obtained; through half-frame length RSS symbol and SSS symbol average power value The comparison of the first target power value can obtain the most reasonable power gain control value in the SSS detection and PBCH reading stages; through the comparison of the subframe RS symbol average power value and the second target power value, the received The most reasonable power gain control value in each stage; the present invention distinguishes the environmental characteristics of the three stages, adopts different power gain control methods in each stage, and improves the flexibility of power control.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention.

Claims (11)

1. A TD-LTE automatic gain control method, the method comprising:

calculating the average power of corresponding symbols in each TD-LTE frame by taking the frame length as a unit in a frequency point scanning and primary synchronization symbol PSS detection stage, taking the half frame length as a unit in an auxiliary synchronization symbol SSS detection and physical broadcast channel PBCH reading stage and taking the subframe length as a unit in a downlink service channel receiving stage respectively; and respectively comparing the average power with the upper power limit and/or the lower power limit, the first target power value and the second target power value to obtain a power gain control value of each stage.

2. The TD-LTE automatic gain control method according to claim 1, wherein in the frequency point scanning and PSS detection stage, the method comprises:

calculating the average power value of each symbol of the current TD-LTE frame by taking the length of the 10ms frame as a unit, determining the maximum average power value, comparing the maximum average power value with the upper power limit and/or the lower power limit, and outputting the power gain control value of the current TD-LTE frame at the current stage to an SSS detection and PBCH reading stage or processing the next TD-LTE frame according to the comparison result.

3. The TD-LTE automatic gain control method according to claim 1, wherein during the SSS detection and PBCH reading phase, the method comprises:

receiving a power gain control value, calculating the average power values of a PSS symbol and a SSS symbol of the current half frame by taking the 5ms half frame length of the TD-LTE frame as a unit, comparing the calculated average power values of the PSS symbol and the SSS symbol of the current half frame with a first target power value, updating and outputting the power gain control value of the current half frame at the current stage to a downlink service channel receiving stage according to the comparison result, and simultaneously processing the next half frame or processing the next half frame.

4. The TD-LTE automatic gain control method according to claim 1, wherein in the downlink traffic channel receiving phase, the method comprises:

and receiving the power gain control value, calculating the RS symbol average power value of the current subframe by taking the 1ms subframe length of the TD-LTE frame as a unit, comparing the calculated RS symbol average power value of the current subframe with a second target power value, updating the power gain control value of the current subframe at the current stage according to the comparison result, and notifying the current User Equipment (UE) or processing the next subframe.

5. The TD-LTE automatic gain control method according to claim 2, wherein the method comprises:

receiving a power gain range indicated by a radio frequency chip, and averagely dividing the power gain range into a plurality of subsections to obtain an average power gain variation;

updating the initial power gain value of a first frame received by the current UE to be the value of the minimum gain value, calculating the average power value of each symbol within the length of the first frame by using an average power calculation method, comparing and finding out the maximum average power value as the maximum average power value of the first frame;

when the maximum average power value of the first frame is larger than the upper power limit, updating the initial power gain value of the first frame to be used as the initial power gain value of the second frame;

when the maximum average power value of the first frame is smaller than the upper power limit and smaller than the lower power limit, updating the initial power gain value of the first frame to be used as the initial power gain value of the second frame;

when the maximum average power value of the first frame is smaller than the upper power limit and simultaneously larger than the lower power limit, updating the initial power gain value of the first frame to be used as the initial power gain value of the second frame;

outputting the maximum average power value of the first frame as a power gain control value of a second frame to the PSS detection and PBCH reading stage;

calculating the average power value of each symbol within the length of the second frame by using an average power calculation method, comparing and finding out the maximum average power value as the maximum average power value of the second frame,

when the maximum average power value of the second frame is larger than the upper power limit, updating the initial power gain value of the second frame to be used as the initial power gain value of the third frame;

when the maximum average power value of the second frame is smaller than the upper power limit and smaller than the lower power limit, updating the initial power gain value of the second frame to be used as the initial power gain value of a third frame;

when the maximum average power value of the second frame is smaller than the upper power limit and simultaneously larger than the lower power limit, updating the initial power gain value of the second frame to be used as the initial power gain value of a third frame;

outputting the maximum average power value of the second frame as a power gain control value of the second frame to the PSS detection and PBCH reading stage;

and so on until all frames received by the UE are completed.

6. The TD-LTE automatic gain control method according to claim 3, wherein the method comprises:

receiving a power output control value sent by the current frame in the frequency point scanning and PSS detection stage, and taking the power output control value as a first half frame initial power gain value of the current frame;

calculating the average power of the PSS symbol and the SSS symbol of the first half frame in the frequency domain according to an average power calculation method, and filtering through a loop filter circuit, wherein the average power value is taken as the average power value of the first half frame of the current frame;

judging whether the first half frame average power value is equal to the first target power value or not, and entering the second half frame processing of the current frame when the first half frame average power value is equal to the first target power value; when the first half frame average power value is not equal to the first target power value, updating the first half frame average power gain value as a current half frame power gain control value, outputting the current half frame average power gain control value to the downlink service channel receiving stage, and simultaneously entering the step of processing a current frame second half frame;

the step of processing the second half frame of the current frame comprises the following steps:

calculating the average power of the PSS symbol and the SSS symbol of the second field in the frequency domain according to an average power calculation method, and filtering through a loop filter circuit, wherein the average power value is taken as the average power value of the second field;

judging whether the second field average power value is equal to the first target power value or not, and entering the third field processing of the current frame when the second field average power value is equal to the first target power value; when the average power value of the second half frame is not equal to the first target power value, updating the average power gain value of the second half frame as the power gain control value of the current half frame, outputting the value to the receiving stage of the downlink service channel, and simultaneously entering the third half frame of the current frame for processing;

and so on until all the half frames received by the UE are completed.

7. The TD-LTE automatic gain control method according to claim 4, wherein the method comprises:

the downlink service channel receiving stage receives the current half-frame power gain control value sent by the PSS detection and PBCH reading stage, performs variable bandwidth processing on the current half-frame power gain control value, and takes the processed current half-frame power gain control value as the initial power gain value of the first subframe of the current half-frame;

calculating the average power of the RS symbols of the first subframe in the frequency domain according to an average power calculation method, and filtering the RS symbols by a loop filter circuit, wherein the average power value is the average power value of the first subframe of the current field;

comparing whether the first subframe average power value is equal to the second target power value or not, and entering the second subframe processing of the current half frame when the first subframe average power value is equal to the second target power value; when the first subframe average power value is not equal to the second target power value, updating the first subframe average power gain value as a current subframe power gain control value and informing the current UE; meanwhile, processing a second subframe of the current field;

the entering process for the second subframe of the current half frame comprises the following steps:

calculating the average power of the RS symbol of the second subframe in the frequency domain according to the average power calculation method, and filtering the RS symbol by a loop filter circuit, wherein the average power value is the average power value of the second subframe of the current field;

comparing whether the average power value of the second subframe is equal to the second target power value or not, and entering the third subframe processing of the current half frame when the average power value of the second subframe is equal to the second target power value; when the second subframe average power value is not equal to the second target power value, updating the second subframe average power gain value as a current subframe power gain control value and informing the current UE; meanwhile, processing a third subframe of the current field;

and the rest is done until all the subframes received by the current UE are finished.

8. A TD-LTE automatic gain control device, the device comprising: the power gain control module comprises a first-stage power gain control module, a second-stage power gain control module, a third-stage power gain control module and a loop filter circuit; wherein,

the first-stage power gain control module is used for calculating the average power value of each symbol of the current TD-LTE frame and determining the maximum average power value by taking the length of the 10ms frame as a unit, and comparing the maximum average power value with the upper power limit and/or the lower power limit to obtain the power gain control value of the stage;

the second-stage power gain control module is used for calculating the average power values of the PSS symbol and the SSS symbol of the current half frame by taking the 5ms half frame length of the TD-LTE frame as a unit, and comparing the calculated average power values of the PSS symbol and the SSS symbol of the current half frame with the first target power value to obtain a power gain control value of the stage;

the third-stage power gain control module is used for calculating the average power value of the RS symbol of the current subframe by taking the 1ms subframe length of the TD-LTE frame as a unit, and comparing the calculated average power value of the RS symbol of the current subframe with a second target power value to obtain a power gain control value of the stage;

and the loop filter circuit is used for filtering the average power value calculated by the second-stage power gain control module and the third-stage power gain control module.

9. The TD-LTE automatic gain control device of claim 8, wherein the first stage power gain control module comprises: the first processing submodule and the first updating output submodule; wherein,

the first processing sub-module is used for calculating the average power value of each symbol of the current TD-LTE frame by taking the length of the 10ms frame as a unit, comparing the average power values of each symbol of the current TD-LTE frame, determining the maximum average power value of the current frame, and comparing the maximum average power value of the current frame with the upper power limit and/or the lower power limit;

the first update output sub-module is configured to update the power gain control value of the current TD-LTE frame according to the comparison result, and send the updated power gain control value to the first processing sub-module as the initial power gain value of the next frame, or output the power gain control value of the current TD-LTE frame to the second-stage power gain control module as the power gain control value of the current frame in the first-stage power gain control module;

the first processing sub-module is further configured to start processing a next frame after receiving the initial power gain value of the next frame from the first update output sub-module.

10. The TD-LTE automatic gain control device of claim 8, wherein the second stage power gain control module comprises: the second processing submodule and the second updating output submodule;

the second processing submodule is used for calculating the average power value of the PSS symbol and the SSS symbol of the current half frame by taking the frame length of 5ms as a unit; comparing the calculated average power values of the PSS symbol and the SSS symbol of the current half frame with the first target power value;

the second update output sub-module is configured to update the current half-frame power gain value according to the comparison result, output the current half-frame power gain value to the third-stage power gain control module, and simultaneously notify the second processing sub-module to perform next half-frame processing or notify the second processing sub-module to perform next half-frame processing;

and the second processing submodule is also used for starting to process the next half frame after receiving the notification sent by the second updating output submodule.

11. The TD-LTE automatic gain control device of claim 8, wherein the third stage power gain control module comprises: a third processing submodule and a third update output submodule; wherein,

the third processing sub-module is used for calculating the average power value of the RS symbol of the reference signal of the current subframe and comparing the calculated average power value of the RS symbol of the current subframe with a second target power value;

the third update output sub-module is configured to update the power gain control value of the current subframe according to the comparison result, notify the current UE of the update, and notify the third processing sub-module of next subframe processing or notify the third processing sub-module of next subframe processing;

and the third processing submodule is further configured to start processing a next subframe after receiving the notification sent by the third update output submodule.