WO2014082504A1

WO2014082504A1 - Automatic gain control method and device in td-lte

Info

Publication number: WO2014082504A1
Application number: PCT/CN2013/085335
Authority: WO
Inventors: 唐凯; 谢一宁; 李焱
Original assignee: 中兴通讯股份有限公司
Priority date: 2012-11-27
Filing date: 2013-10-16
Publication date: 2014-06-05
Also published as: CN103841633B; CN103841633A

Abstract

Disclosed is an automatic gain control method in TD-LTE. The method comprises: respectively calculating average power of corresponding symbols in all TD-LTE frames in stages of frequency point scanning and primary synchronization symbol (SS) detection in the unit of a frame length, in stages of secondary synchronization symbol (SSS) detection and PBCH reading in the unit of a half frame length, and in a stage of downlink traffic channel receiving in the unit of a subframe length; and respectively obtaining a most reasonable power gain control value of each stage by comparing the average power with an upper power limit and/or a lower power limit, a first target power value, and a second target power value. Further disclosed is an automatic gain control device in TD-LTE. According to the present invention, environmental characteristics of tree stages are differentiated, and the flexibly of power control is improved.

Description

TD-LTE automatic gain control method and device

The present invention relates to a Long Term Evolution (LTE) wireless communication technology, and specifically relates to a Time Division Long Term Evolution (AGC) automatic gain control (AGC) method and apparatus. Background technique

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

Currently, the LTE system includes TD-LTE and Frequency Division Duplexing Long Term Evolution (FDD-LTE), because TD-LTE can use the same frequency point for data transmission in the uplink and downlink. It saves bandwidth resources and is more favored by researchers.

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

In the prior art, the TD-LTE downlink signal processing process includes the following three phases: a frequency point scanning and a primary synchronization symbol (PSS) detection phase, and a secondary synchronization symbol (SSS, Secondary Synchronization Signal) detection. And a physical broadcast channel (PBCH, Physical Broadcasting Channel) reading phase and a downlink traffic channel receiving phase; wherein, the frequency point scanning is mainly used for the signal power average value and power in the main diversity antenna The large value and the minimum power are scanned and the interference signal is checked. By troubleshooting the interference signal, the PSS detection determines the position of the PSS symbol in the TD-LTE field length, and the UE can know the 5 ms synchronization information; the SSS detection is used to determine The position of the SSS symbol in the frame length, the UE can know the 10ms synchronization information, and the PBCH can read and retrieve the TD-LTE frame number synchronization information; the 5ms synchronization information, the 10ms synchronization information, and the frame number synchronization information set become the TD. - LTE downlink synchronization information, the frame synchronization information enables the user equipment (UE, User Equipment) to smoothly receive the signal sent by the base station through the downlink traffic channel.

In the above three phases, when the signal sent by the base station is processed through layer processing, interference is unavoidable, which weakens the strength of the signal. In order to ensure that the signal sent by the base station can reach the UE smoothly, the three phases are introduced. A certain power control method. In the prior art, the conventional method is to introduce the same power control method into each stage to ensure signal strength stability, but ignores the characteristics of the environment in which the signals of the three stages are located, then, the same power control method Applying to these three different stages becomes inflexible, so there is an urgent need for a power control method that can be flexibly applied to these three stages.

Summary of the invention

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

To achieve the above objective, the technical solution of the embodiment of the present invention is implemented as follows:

An embodiment of the present invention provides a TD-LTE automatic gain control method, where the method includes: respectively, in a frequency point scanning and a primary synchronization symbol PSS detection phase, a frame length unit, a secondary synchronization symbol SSS detection, and a physical broadcast channel PBCH read. The taking phase is in units of a field length, and the downlink traffic channel receiving phase is in units of subframe lengths, and the average power of the corresponding symbols in each TD-LTE frame is compared with the power value of the second target, and each phase is obtained. The most reasonable power gain control value. In the foregoing solution, in the frequency scanning and PSS detection phase, the method includes: calculating, according to a frame length of 10 ms, an average power value of each symbol of a current TD-LTE frame, and determining, according to the comparison result, outputting a current TD-LTE frame. At this stage, the power gain control value is to the SSS detection and PBCH reading stage, or the processing of the next TD-LTE frame is performed.

In the foregoing solution, in the SSS detection and PBCH reading phase, the method includes: receiving a power gain control value outputted by the frequency point scanning and the PSS detection phase, and calculating the current half by using a 5 ms field length of the TD-LTE frame. Frame PSS symbol, SSS symbol average power value, compare the calculated current field PSS symbol, SSS symbol average power value with the first target power value, update and output the current field power gain control value of the current field according to the comparison result The processing of the next half frame or the processing of the next half frame is performed simultaneously to the downlink traffic channel receiving phase.

In the above solution, in the downlink traffic channel receiving phase, the method includes: receiving a power gain control value outputted by the SSS detection and the PBCH reading phase, and calculating a current sub-unit in units of a 1 ms subframe length of the TD-LTE frame. The frame reference signal RS symbol average power value, and compares the calculated current subframe RS symbol average power value with the second target power value, and updates the current subframe power gain control value of the current subframe according to the comparison result and notifies the current user The device UE, or performs processing of the next subframe.

In the above solution, the method includes:

Receiving a power gain range indicated by the radio frequency chip, and dividing the power gain range into a plurality of sub-sections to obtain an average power gain variation;

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

Updating the first frame initial power gain value as the second frame initial power gain value when the first frame maximum average power value is greater than the power upper limit; Updating the first frame initial power gain value as the second frame initial power gain value when the first frame maximum average power value is less than the power upper limit and less than the power lower limit;

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

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

Using the average power calculation method, the average power value of each symbol in the second frame length is calculated, and the maximum average power value is compared and found as the maximum average power value of the second frame.

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

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

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

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

In the above solution, the method includes:

Receiving a power output control value output by the current frame of the frequency point scanning and PSS detection stage, and serving as a first power frame initial power gain value of the current frame;

According to the average power calculation method, the average power of the PSS symbol and the SSS symbol in the frequency domain in the first field is calculated, and filtered by the loop filter circuit, where the average power value is used as the average power value of the first frame of the current frame;

Determining whether the first half frame average power value is equal to the first target power value, and when the first field average power value is equal to the first target power value, entering the second frame processing of the current frame; When the half frame average power value is not equal to the first target power value, the first field average power gain value is updated as the current field power gain control value, and is output to the downlink traffic channel receiving phase, and simultaneously enters the current frame. Two fields are processed;

The entry processes the second field of the current frame as:

According to the average power calculation method, the average power of the PSS symbol and the SSS symbol in the frequency domain in the second field is calculated, and filtered by the loop filter circuit, where the average power value is used as the average power value of the second half frame;

Determining whether the average power value of the second field is equal to the first target power value, and when the average power value of the second field is equal to the first target power value, entering the third field processing of the current frame; When the power value is not equal to the first target power value, updating the second field average power gain value as the current field power gain control value, outputting to the downlink traffic channel receiving phase, and simultaneously entering the third frame of the current frame Process

And so on, until all the fields received by the UE are completed.

In the above solution, the method includes:

The downlink traffic channel receiving phase receives the current field power gain control value outputted by the PSS detection and PBCH reading phases, and performs variable bandwidth processing on the current field power gain control value, and the processed current field power is processed. The gain control value is used as the first subframe initial power gain value of the current field;

According to the average power calculation method, the average power of the first subframe RS symbol in the frequency domain is calculated, and after filtering by the loop filter circuit, 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 and the second target power value are equal, when the first subframe average power value is equal to the second target power value, entering the second subframe processing of the current field; when the first subframe When the average power value is not equal to the second target power value, the first subframe average power gain value is updated as the current subframe power gain control value, and notified to the current UE; Half frame second subframe processing;

The entry is processed for the second subframe of the current field as:

According to the average power calculation method, the average power of the RS symbol of the second subframe in the frequency domain is calculated, and after filtering by the loop filter circuit, the average power value is the average power value of the second subframe of the current field;

Comparing whether the second subframe average power value is equal to the second target power value, when the second subframe average power value is equal to the second target power value, entering the third subframe processing of the current field; when the second subframe When the average power value is not equal to the second target power value, updating the second subframe average power gain value as the current subframe power gain control value, and notifying the current UE; meanwhile, entering the third subframe processing of the current field;

And so on, until all the subframes received by the current UE are completed.

The embodiment of the invention further provides a TD-LTE automatic gain control device, the device comprising: 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 ; among them,

The first stage power gain control module is configured to calculate, according to a frame length of 10 ms, an average power value of each symbol of the current TD-LTE frame and determine a maximum average power value, and a maximum average power value and a power upper limit and/or a power lower limit. For comparison, the most reasonable power gain control value for the frequency sweep and the primary sync symbol PSS detection phase is obtained;

The second stage power gain control module is configured to calculate an average power value of the current field PSS symbol and the SSS symbol in units of 5 ms field length of the TD-LTE frame, and calculate the current field PSS symbol, Comparing the average power value of the SSS symbol with the first target power value, and obtaining the most reasonable power gain control value of the secondary synchronization symbol SSS detection and the physical broadcast channel PBCH reading phase;

The third stage power gain control module is configured to calculate an average power value of the current subframe RS symbol by using a 1 ms subframe length of the TD-LTE frame, and calculate the calculated current subframe reference. Comparing the average power value of the signal RS symbol with the second target power value to obtain the most reasonable power gain control value in the downlink traffic channel receiving phase;

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

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

The first processing sub-module is configured to calculate an average power value of each symbol of the current TD-LTE frame in units of a frame length of 10 ms, and compare the average power value of each symbol of the current TD-LTE frame to determine a maximum average power of the current frame. a value that compares the current frame maximum average power value with a power upper limit and/or a lower power limit;

The first update output submodule is configured to update the current TD-LTE frame power gain control value as a next frame initial power gain value and send it to the first processing submodule, or output the current TD- according to the comparison result. LTE frame power gain control value to the second stage power gain control module as a 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 the next frame after receiving the next frame initial power gain value from the first update output sub-module.

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 configured to calculate a PSS symbol and an SSS symbol average power value of the current field in units of 5 ms frame length; and compare the calculated current field PSS symbol, the SSS symbol average power value, and the first target. Power value

The second update output submodule is configured to update the current field power gain value according to the comparison result and output the result to the third stage power gain control module, and notify the second processing submodule to perform the next half frame processing, Or notifying the second processing sub-module to perform the next half of the frame processing; The second processing submodule is further configured to, after receiving the notification sent by the second update output submodule, start processing the lower half of the frame.

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

The third processing sub-module is configured to calculate a current sub-frame reference signal RS symbol average power value, and compare the calculated current sub-frame RS symbol average power value and a second target power value; the third update output And the module is configured to update the current subframe power gain control value according to the comparison result, and notify the current UE, and notify the third processing sub-module to perform the next subframe processing, or notify the third processing sub-module to perform the next One subframe processing;

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

The TD-LTE automatic gain control method and device provided by the embodiments of the present invention are directed to the three-stage environmental characteristics of the TD-LTE downlink signal processing process, which are respectively in the frame length, the half frame length, and the subframe length. Calculating the average power of the corresponding symbols in each TD-LTE frame, and comparing the two target power values to obtain the most reasonable power gain control value for each phase; the embodiment of the present invention distinguishes the TD-LTE downlink signal The environmental characteristics of the three phases included in the process increase the flexibility of power control.

DRAWINGS

1 is a schematic flowchart of an implementation of a TD-LTE automatic gain control method according to an embodiment of the present invention; FIG. 2 is a schematic flowchart of an implementation process of a TD-LTE automatic gain control method in a frequency point scanning and PSS detection phase according to an embodiment of the present invention;

3 is a schematic flowchart of an implementation process of a TD-LTE automatic gain control method in an SSS detection and a PBCH reading phase according to an embodiment of the present invention; 4 is a schematic flowchart of an implementation process of a TD-LTE automatic gain control method in a downlink traffic channel receiving phase according to an embodiment of the present invention;

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

detailed description

The TD-LTE automatic gain control method provided by the embodiment of the present invention includes: a frame length unit, an SSS detection, and a PBCH reading phase in units of a half frame length and a downlink service in a frequency sweep and a PSS detection phase, respectively. The channel receiving phase calculates the average power of the corresponding symbols in each TD-LTE frame in units of subframe lengths; respectively, the average power and the preset power upper limit and/or the power lower limit, the first target power value, and the first The comparison of the two target power values yields the most reasonable power gain control value for each phase.

Here, the frequency sweep and PSS detection phases calculate the average power of each symbol of each TD-LTE frame; the SSS detection and PBCH read phases calculate the PSS symbols and SSS symbols in each TD-LTE field. Average power; The downlink traffic channel reception phase calculates the average power of the reference signal (RS, Reference Signal) symbols in each TD-LTE subframe.

The power upper limit, the power lower limit, the first target power value, and the second target power value may be flexibly set according to actual conditions.

As shown in FIG. 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 10 ms frame length and determine the maximum average power value, and compare the calculated maximum average power value with the power upper limit and/or the power lower limit, according to comparison As a result, the current TD-LTE frame is outputted at this stage of the power gain control value to the SSS detection and PBCH reading stage, or the next TD-LTE frame processing is performed.

Here, the environment characteristics of the frequency point scanning and PSS detection stages are in units of 10 ms frame length; specifically, since the current UE has not acquired any synchronization information for the frequency point scanning and PSS detection stages, therefore, in one TD- The LTE frame length is 10 ms, in the entire cell. Both the uplink and downlink signals are likely to be used by the current UE as an average power estimate. Then, for the environmental characteristics of this stage, a statistical AGC method can be used to obtain better power gain control.

The current UE receives the RF circuit signal, and the RF circuit includes a power amplifier, an analog-to-digital converter (ADC), an RF chip, and the like; wherein, the RF chip manufacturer has indicated the RF chip when the RF chip is shipped from 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 depending on the type of the RF chip, and also varies from manufacturer to manufacturer.

As shown in FIG. 2, the specific processing procedure of step 10 may be:

The power gain range M indicated by the radio frequency chip is equally divided into N sub-segments, and the average power gain of each sub-segment is M/N (db), and M/N (db) is taken as the average power gain variation, where N is positive Integer

Here, it is assumed that the number of all TD-LTE frames received by the current UE is i, and i is a positive integer, then all received TD-LTE frames may be arranged into a first frame, a second frame, an ith frame. First processing the first frame, updating the initial power gain value A_G (1) of the first frame as 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, and calculating the average power value of each symbol in the first frame length;

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

Comparing 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 , updating 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, enters processing for the second frame; when the maximum average power value of the first frame is less than the power upper limit P _maxlim , compares the maximum average power value and the power lower limit P _{minlim of the} first frame the size of; When the first frame maximum average power value is less than the power lower limit P _MINLIM , the first frame initial power gain value _{A_G} ( 2 ) =AG ( 1 ) -M/N is updated as the second frame initial power gain value, and the pair is entered. Second frame processing; when the first frame maximum average power value is greater than the power lower limit P _MINLIM , output the first frame initial power gain value _{A_G} (1) to the SSS detection and PBCH reading phase, as the first frame at the frequency point Power gain control value resultl output during scanning and PSS detection phase;

The entering the second frame processing 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, and calculating an average power value of each symbol in the second frame length;

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

Comparing the maximum average power value of the second frame with 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 , updating the second frame initial power gain value A_G ( 3 ) = A_G ( 2 ) +M/N, as the initial power gain value of the third frame, enters processing for the third frame; when the maximum average power value of the second frame is less than the upper power limit P _MAXLIM , compares the maximum average power value of the second frame with the lower power limit P _MINLIM the size of;

When the second frame maximum average power value is less than the power lower limit P _MINLIM , the second frame initial power gain value A_G ( 3 ) = A_G ( 2 ) -M/N is updated, as the third frame initial power gain value, entering the third Frame processing; when the maximum average power value of the second frame is greater than the power lower limit P _MINLIM , outputting the second frame initial power gain value _{A_G} ( 2 ) as the power gain control of the second frame in the frequency sweep and PSS detection phases Value resultl;

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

In the step 10, the power upper limit P _MAXLIM and the power lower limit P _{MINLIM are} preset; for different frames, the power upper limit P _MAXLIM and the power lower limit P _{MINLIM may} take the same value or different values; Wherein, the upper limit of the power limit is lOloglO ( 2 ^m ) +15 (db), and the lower limit of power Pminiim ranges from lOloglO ( 2 ^m ) -15 (db), m is the bit width of the ADC device; ADC The device's bit width is already specified in the bit width range when the ADC device is shipped from the factory.

In addition, the value of the parameter N ranges from 3 to 6, which can be flexibly adjusted according to the actual environment (such as the external field test). When the actual environment requires fast convergence and the range of the gain accuracy is not high, N can be taken as a smaller value; On the contrary, N may be a relatively large value; since this stage is processing the frame, in this stage, after calculating the average power value of each symbol within each frame length, it is not necessary to perform filtering processing through the loop filter circuit.

As described above, after the end of the frequency sweep and PSS detection phase, 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 has already known the 5 ms synchronization information at this time. In the SSS detection and PBCH reading phases, the 5ms synchronization information is fully utilized for SSS detection and automatic gain control during the PBCH reading phase.

Step 20: Receive a power gain control value, and calculate an average power value of the current field PSS symbol and the SSS symbol in units of 5 ms field length of the TD-LTE frame, and calculate the current field frame PSS symbol and the SSS symbol average power value. Comparing the first target power values, updating and outputting the current field according to the comparison result, performing the processing of the next half frame or the processing of the lower half frame in the phase of the power gain control value to the downlink traffic channel receiving phase;

Here, the environment characteristics of the PSS detection and PBCH reading phases are in units of 5 ms field length of the TD-LTE frame;

As can be seen from the above scheme, the frequency sweep and PSS detection phases are for 10ms.

After the processing of the TD-LTE frame, after the frequency point scanning and the PSS detection phase are finished, the current UE already knows the 5 ms synchronization information, that is, the field synchronization information, and determines the signal time window of the PSS symbol; then, in the SSS detection, it can be determined. Signal time window of the SSS symbol;

Here, the signal time window of the PSS symbol and the SSS symbol can be regarded as two points on the time axis, that is, the position of the PSS symbol and the SSS symbol in the TD-LTE field length has been determined. The PSS symbol and the sss symbol in the half frame length are extracted; it can be seen that this stage is mainly processed for the TD-LTE field length; here, the current 1 Oms TD-LTE frame is divided into the first half. The frame and the second field, the first field and the second field are both 5 ms frame length.

As shown in FIG. 3, the specific processing procedure of step 20 may be:

The resultl outputted in the receiving frequency point scanning and PSS detection stage is used as the initial power gain value of this stage;

For the TD-LTE system, the resultl is used as the initial power gain value of the first subframe in this stage. After extracting the PSS symbol and the SSS symbol of the first field of the current 10ms TD-LTE frame, the first half is calculated by using the prior art. Frame PSS symbol, the average power of the SSS symbol in the frequency domain, and performing multiple accumulation and averaging, and then filtering by the loop filter circuit to filter out noise, and the result is the first field average power value pi;

Determining whether the first field average power value pi is equal to the first target power value Target. When pi is equal to Target, using resultl as the second field initial power gain value, entering the second field of the current 10 ms TD-LTE frame. Processing; when pi is not equal to Target, updating the power gain control value result2 = resultl + (Target-pl ) of the first field at this stage, and outputting result2 to the downlink traffic channel receiving phase, with result2 as the second field The initial power gain value enters the processing of the second half of the current 10 ms TD-LTE frame;

The processing of entering the second field of the current 10 ms TD-LTE frame is specifically: extracting the PSS symbol and the SSS symbol of the second field of the current 10 ms TD-LTE frame, and calculating the second field average by using the prior art. The power value p2; then, determining whether the second field average power value p2 is equal to the target power value Target, and when p2 is equal to Target, entering the first field of the next TD-LTE frame; when p2 is not equal to Target, updating The second field is at this stage power gain control value result 2 = p_old + (Target- p2 ) and outputs result 2 to the downlink traffic channel reception phase;

Here, when the condition from "pi is not equal to Target" is established until this time, p_old= result2 is taken; when the condition from "p1 is equal to Target" is established until this time, p_old= Result 1; And so on, until all the fields received by the current UE are processed.

Here, the value of the first target power value Target is designed according to the bit width m of the actually selected ADC device in the TD-LTE system, and the risk of saturation under a large noise/interference condition, usually taking Target=2 ^m ₀

At the same time, since the phase is processed for the TD-LTE field, the half frame time is short. In the loop filter circuit, a relatively large loop filter coefficient needs to be set in advance to ensure fast convergence of the field symbol.

In this description, when the technical solution of the embodiment of the present invention is described, the loop filter coefficients of the loop filter coefficients are all in the range of 0.04 to 0.5.

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

Step 30: Receive a power gain control value, calculate an average power value of the current subframe RS symbol by using a lms subframe length of the TD-LTE frame, and calculate the calculated current subframe RS symbol average power value and the second target power value. Comparing, updating the power gain control value of the current subframe in the current stage according to the comparison result, and notifying the current UE, or performing the next subframe processing;

Here, the environment characteristic of the downlink traffic channel receiving phase is in units of the lms subframe length of the TD-LTE frame;

For the downlink traffic channel reception phase, 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, the current UE can determine each 1 ms through downlink synchronization. The position of the reference signal (RS, Referenc Signal) in the sub-frame is in the respective sub-frames. Then, the RS in each sub-frame can be extracted. It can be seen that this stage is mainly for each of TD-LTE. The lms subframe is processed; here, the current 5 ms TD-LTE field is divided into a first subframe, a second subframe, and a third The subframe, the fourth subframe, and the fifth subframe, each subframe is lms long.

Because the SSS detection and PBCH reading phase are different from the bandwidth in this phase, this phase takes the 20M bandwidth TD-LTE system as an example, because the power and bandwidth are proportional, that is, as the bandwidth increases, the power also Correspondingly enhanced. In order to achieve better connection between the SSS detection and the PBCH read phase and this phase, the power gain control value result2 sent in the SSS detection and PBCH read phases needs to be subjected to variable bandwidth processing first.

As shown in FIG. 4, the specific processing procedure of step 30 may be:

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

Result2_new = result2 - 10*logl0(B _new IB _old ) ( 1 )

Among them, the variable B. _Ld is the bandwidth of the TD-LTE system used in the SSS detection and PBCH reading phase; B _{new is} the bandwidth of the TD-LTE system used in this phase.

Reading result2_new is the initial power gain value of the first subframe of this stage;

After extracting the first subframe RS symbol of the current 5 ms TD-LTE field, the average power of the first subframe RS symbol in the current field is calculated by using the prior art, and the loop filtering circuit is used for loop filtering. In order to filter out noise, the result is the first sub-frame average power value M_pl; determine whether the first sub-frame average power value M_pl is equal to the second target power value Tar, and when M_pl is equal to Tar, result2_new is used as the second sub- Frame initial power gain value, processing the second subframe; when M_pl is not equal to Tar, updating the power gain control value result3 = result2_new+ ( Tar- M_pl ) of the first subframe at this stage, and notifying the current value of result3 The UE processes the second subframe by using the result 3 as the initial power gain value of the second subframe;

The processing of the second subframe may be: extracting the second subframe RS symbol of the current 5 ms TD-LTE field, and calculating the average power of the second subframe RS symbol in the frequency domain by using the prior art. , using a loop filter circuit for loop filtering to filter out noise, the result is the second sub-frame average power value M_p2; Determining whether the second sub-frame average power value M_p2 is equal to the second target power value Tar. When M_p2 is equal to Tar, the result of the second sub-frame is processed by the result of the second sub-frame initial power gain value; when the M_p2 is not When it is equal to Tar, the second sub-frame is updated at this stage of the power gain control value result3 = Y+ ( Tar- M_p2 ), and the value of result3 is notified to the current UE, and result3 is the initial power gain value of the third subframe, for the third sub-frame. Frame processing;

Here, when the condition from "M_pl equals Tar" is established to this time, Y = result2 - new; when the condition from "M_pl is not equal to Tar" is established until this time, Y = result3;

And so on, 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, and usually takes Target=2 ^m , and the bit width m of the ADC device is marked with the bit width at the factory. .

Considering that the control frequency required in this stage is high, in the loop filter circuit, a smaller loop filter coefficient needs to be selected to ensure the stability of the downlink.

Based on the above TD-LTE automatic gain control method. The embodiment of the present invention further provides a TD-LTE automatic gain control device. As shown in FIG. 5, the device includes: a first stage power gain control module 50, a second stage power gain control module 51, and a third stage power. a gain control module 52 and a loop filter circuit 53; wherein

The first stage power gain control module 50 is configured to calculate, according to a frame length of 10 ms, an average power value of each symbol of the current TD-LTE frame and determine a maximum average power value, and a maximum average power value and a 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 configured to calculate an average power value of the current field PSS symbol and the SSS symbol in units of 5 ms field length of the TD-LTE frame, and calculate the current field PSS symbol. And comparing the average power value of the SSS symbol 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 configured to calculate an average power value of the current subframe RS symbol in units of 1 ms subframe length of the TD-LTE frame, and calculate the average power of the current subframe RS symbol. The 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 second stage power gain control module 51 and the third stage power gain control module 52.

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 the M average into N sub-segments, and takes M/N ( db ) as the average power gain change amount; The initial power gain value of the first frame received by the UE is the value of the minimum gain value. The average power value of each symbol in the length of the first frame is calculated by using the average power calculation method in the prior art, and the maximum value is compared and found. Average power value, as the maximum average power value of the first frame;

Updating the first frame initial power gain value as the second frame initial power gain value when the first frame maximum average power value is greater than the power upper limit;

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

When the maximum average power value of the first frame is less than the upper power limit and greater than the lower power limit, the initial power gain value of the first frame is updated as the initial power gain value of the second frame; and 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 the received frames are completed.

Here, the power gain range and the minimum gain value are indicated when the RF chip is shipped from the factory. Value.

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 frame of the current frame;

According to the prior art average power calculation method, the second stage power gain control module 51 may calculate the average power of the first field PSS symbol and the SSS symbol in the frequency domain of the current frame, and then the second stage power gain control module. 51, the calculated average power is sent to the loop filter circuit 53, filtered by the loop filter circuit 53, and then returned to the second stage power gain control module 51, where the average power value returned is Half frame average power value;

The second stage power gain control module 51 receives and determines whether the first field average power value is equal to the first target power value;

When the first field 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. a frame initial power gain value, according to the foregoing technical solution, starting to process the second field of the current frame;

When the first field average power value is not equal to the first target power value, the second stage power gain control module 51 updates the first field average power gain value as the current field power gain control value, and outputs the current The third stage power control module 52; at the same time, using the updated first field average power gain value as the second field initial power gain value, according to the above technical solution, starting to process the second field of the current frame;

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

The third stage power gain control module 52 receives the current field power gain control value sent by the second stage power gain control module 51, and uses the formula (1) to perform variable bandwidth on the current field power gain control value. Processing, taking the processed current field power gain control value as The initial power gain value of the first subframe of the current field;

According to the prior art average power calculation method, 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. After the loop filtering circuit 53 performs filtering, it returns to the third stage power gain control module 52, where the average power value returned is the first sub-frame average power value; the first sub-frame average power value is compared with the first Whether the two target power values are equal;

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

When the first sub-frame average power value is not equal to the second target power value, the third-stage power gain control module 52 updates the first sub-frame average power gain value as the current sub-frame power gain control value, and notifies the current At the same time, the updated first subframe average power gain value is used as the second frame initial power gain value, and the second subframe of the current field is processed according to the foregoing technical solution;

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

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

The first processing sub-module 500 is configured to calculate an average power value of each symbol in the current TD-LTE frame in units of 10 ms frame length, and compare the average power value of each symbol in the current TD-LTE frame to determine a maximum average value of the current frame. a power value that compares a current frame maximum average power value with a power upper limit and/or a power lower limit;

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

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

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

The second processing sub-module 510 is configured to calculate a current power value of the PSS symbol and the SSS symbol in the current field in units of 5 ms frame length; and compare the calculated current field PSS symbol and the SSS symbol average power value with the first Target power value size;

The second update output sub-module 511 is configured to update and output the current field power gain value to the third-stage power gain control module 52 according to the comparison result, and notify the second processing sub-module 510 to perform the lower half. Frame processing; or only the second processing sub-module 510 is notified to perform the next half of the frame processing;

The second processing sub-module 510 is further configured to receive the notification sent by the second update output sub-module 511 and begin processing the next half of the frame.

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

The third processing sub-module 520 is configured to calculate a variable power bandwidth, calculate an 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;

The third update output sub-module 521 is configured to update the current subframe power gain control value according to the comparison result, and notify the current UE, and notify the third processing sub-module 520 to perform the next subframe processing; or only notify The third processing sub-module 520 performs the next subframe processing;

The third processing sub-module 520 is further configured to begin processing the next subframe after receiving the notification issued by the third update output sub-module 521.

Specifically, when the current UE is in the frequency scanning and PSS detection phase, first, the The first processing sub-module 500 receives the power gain range M indicated by the radio frequency chip, and divides the M average into N sub-segments, then M/N (db) is the average power gain of each sub-segment;

Here, M/N ( db ) is taken as the average power gain variation, where N is a positive integer; the RF chip is shipped with the minimum gain value G_min and the maximum gain value G_max;

The current UE is connected to all the frames in order, which is the first frame, the second frame, the i-th frame, and i is a positive integer;

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

Using the average power calculation method in the prior art, the first processing sub-module 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 The maximum average power value, as the maximum average power value of the first frame;

When the first frame maximum average power value is greater than the power upper limit P _maxlim , the first update output sub-module 501 updates the first frame initial power gain value _{A_G} ( 2 ) =AG ( 1 ) +M/N, as the first a second frame initial power gain value, the first update output sub-module 501 outputs A-G ( 2 ) at this time to the first processing sub-module 500;

When the first frame maximum average power value is less than the power upper limit P _maxlim , the first processing submodule 500 compares 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 P _minlim , the first update output sub-module 501 updates the first frame initial power gain value A_G ( 2 ) =A_G ( 1 ) -M/N as the second frame. The initial power gain value, the first update output sub-module 501 outputs A-G ( 2 ) at this time to the first processing sub-module 500;

When the first frame maximum average power value is greater than the power lower limit P _minlim , the first update output sub-module 501 outputs the _{A_G} ( 1 ) value to the second-stage power gain control module 51, and specifically sends the a second processing sub-module 510, which is a power gain control value resultl outputted in the frequency point scanning and PSS detection phase of the first frame; After the first processing sub-module 500 receives the A-G(2), using the average power calculation method in the prior art, the first processing sub-module 500 calculates the average power value of each symbol in the second frame length. And comparing the average power value of each symbol in 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 P _maxlim , the first update output sub-module 501 updates the second frame initial power gain value _{A_G} ( 3 ) =AG ( 2 ) +M/N, as the first a three-frame initial power gain value, the first update output sub-module 501 outputs A-G(3) at this time to the first processing sub-module 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 compares the maximum average power value of the second frame with the power lower limit P _minlim .

When the second frame maximum average power value is less than the power lower limit P _minlim , the first update output sub-module 501 updates the second frame initial power gain value A_G ( 3 ) =A_G ( 2 ) -M/N as the third frame. The initial power gain value, the first update output sub-module 501 outputs A-G(3) at this time to the first processing sub-module 500;

When the first frame maximum average power value is greater than the power lower limit P _minlim , the first update output sub-module 501 outputs the _{A_G} ( 2 ) value to the second-stage power gain control module 51, and specifically sends the The second processing sub-module 510, as the second frame, the power gain control value resultl outputted by the first stage power gain control module 50;

According to the above technical solution, after receiving the A_G(3), the first processing submodule 500 completes the processing of the third frame in conjunction with the first update output submodule 501, and so on, until the receiving of the current UE is completed. Processing to all frames.

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 set in the first processing submodule 500; for different frames, The power upper limit P _maxlim and the power lower limit P _{minlim may} take the same value or may take different values; Among them, the upper limit of the power limit is lOloglO ( 2 ^m ) +15 (db), and the lower limit of power Pminiim is lOloglO ( 2 ^m ) -15 (db), m is the position of the ADC device in the RF circuit. Wide; the signal sent by the radio frequency circuit is received by the current UE;

In addition, the value of the parameter N ranges from 3 to 6, which is preset in the first stage power gain control module 50, specifically, is set in the first processing submodule 500; The processing performed by the frame, so after the first processing sub-module 500 calculates the average power value of each symbol in the length of each frame, it is no longer 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 PSS detection and PBCH reading phase, the second processing submodule 510 receives the result1 sent by the first stage power gain control module 50 as an initial power gain value;

At this stage, the current UE can learn the synchronization information of 5 ms, so the second-stage power gain control module 51 can determine the PSS symbol and the SSS symbol position in each field, and can extract and calculate the PSS in each field. Symbol, SSS symbol average power value;

Taking a TD-LTE frame received by the current UE as an example, the one TD-LTE frame may be divided into a first field and a second field.

The second processing sub-module 510 receives the resultl sent by the first-stage power gain control module 50 as the initial power gain value of the first field, and calculates the first half according to the method for calculating the result of the average power into the prior art. Frame PSS symbol, average power of the SSS symbol in the frequency domain, then the second processing sub-module 510 sends the calculated average power to the loop filter circuit 53, after being filtered by the loop filter circuit 53, and then Returning the average power to the second processing sub-module 510, where the average power value returned is the first field average power value pi;

The second processing sub-module 510 determines whether the first field average power value p 1 is equal to the first target power value Target.

When pi is equal to Target, using resultl as the second field initial power gain value, the The second processing sub-module 510 starts processing the second field;

When the pi is not equal to the Target, the second update output sub-module 511 updates the first field power gain control value result2, and outputs the result2 to the third-stage power control module 52, and outputs the result to the third processing sub-module. 520; using result2 as the second field initial power gain value, the second update output sub-module 511 notifying the second processing sub-module 510 to enter the second field processing;

Where result2= result 1+ ( Target-pl );

After receiving the notification (result2 as the second field initial power gain value) or self-identification (resultl as the second field initial power gain value), the second processing sub-module 510 needs to perform the next half frame processing, and then starts to The second field is processed: the second field initial power gain value is substituted into the prior art average power calculation method to calculate the average power of the second field PSS symbol and the SSS symbol in the frequency domain, and then the second processor The module 510 sends the calculated average power to the loop filter circuit 53, and after filtering by the loop filter circuit 53, returns the average power to the second processing sub-module 510, and returns the average power value. The second half frame average power value p2;

The second processing sub-module 510 determines whether the second field average power value p 1 is equal to the first target power value Target.

When p2 is equal to Target, the second field initial power gain value is used as the third field initial power gain value, and the second processing sub-module 510 starts processing the third field;

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

Wherein, when the condition from "pi is not equal to Target" is established until this time, then p_old= Result2; when the condition from "pi equals Target" is established until this time, p_old = result 1 is taken; according to the above technical solution, the second processing sub-module 510 receives the notification or recognizes that it needs to be performed. After the first field of one frame, combined with the second update output sub-module 511, the processing of the first field of the next frame is completed; until all the fields received by the current UE are processed.

Here, the first target power value Target is pre-set in the second-stage power gain control module 51, and is specifically disposed in the second processing sub-module 510.

When the current UE is in the downlink traffic channel receiving phase, the current UE can learn 5 ms synchronization information, 10 ms 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 in turn, can extract and calculate an average power value of RS symbols per subframe;

Taking a TD-LTE field received by the current UE as an example, the one TD-LTE field may be divided into a first subframe, a second subframe, a third subframe, a fourth subframe, and a fifth subframe. ;

Because the bandwidth 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 the power gain control value result2 of the control module 51, the variable bandwidth processing is performed according to the formula (1), and then the result2_new after the variable bandwidth processing is completed is used as the initial power gain value of the first subframe;

The third processing sub-module 520 substitutes result2_new into the prior art average power calculation method, calculates the average power of the first subframe RS symbol in the frequency domain, and then the third processing sub-module 520 sends the calculated The average power is sent to the loop filter circuit 53 and filtered by the loop filter circuit 53 to return the average power to the third processing sub-module 520. At this time, the average power value returned is the first sub-frame average power. Value ^ ^)1;

Next, the third processing sub-module 520 determines whether the first subframe average power value M_pl and the second target power value Tar are equal. When M_p 1 is equal to Tar, with result 2 — new as the second subframe initial power gain value, the third processing sub-module 520 starts processing the second subframe;

When M_pl is not equal to Tar, the third update output sub-module 521 updates the first subframe power gain control value result3= result2_new+ ( Tar-M_pl ), and notifies result 3 to the current UE; and results3 is used as the second field initial a power gain value, the third update output sub-module 521 notifying the third processing sub-module 520 to enter a second subframe processing;

The third processing sub-module 520 needs to perform the next subframe for receiving the notification (using result3 as the second field initial power gain value) or by itself (with result2_new as the second field initial power gain value) After processing, the second subframe is processed in conjunction with the third update output submodule pair 521:

The third processing sub-module 520 calculates the average power of the second subframe RS symbol in the frequency domain according to the prior art average power calculation method, and then the third processing sub-module 520 sends the calculated average power to the The loop filter circuit 53 is filtered by the loop filter circuit 53, and then returns the average power to the third processing sub-module 520. At this time, the average power value returned is the second sub-frame average power value M_pl;

Next, the third processing sub-module 520 determines 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, with result2_new as the third subframe initial power gain value, the third processing sub-module 520 starts processing the third subframe;

When M_p2 is not equal to Tar, the third update output sub-module 521 updates the second subframe power gain control value result3 = Y+ ( Tar- M_p2 ), and notifies the current UE to the result 3; the third update output sub-module 521, the third processing sub-module 520 is notified to enter a process of processing the third subframe;

Here, when the condition from "M_pl is equal to Tar" is established until this time, Y = result2 - new; when the condition from "M_pl is not equal to Tar" is established until this time, Y = result3; According to the foregoing technical solution, after receiving the notification, the third processing sub-module 520 combines with the second update output sub-module 521 to complete processing on the next subframe; until all the UEs received by the current UE are processed. frame.

Here, the second target power value Tar is preset in the third stage power gain control mode 52, and is specifically disposed in the third processing submodule 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, through downlink synchronization, the third processing sub-module 520 can determine each The position of the reference signal RS ( Referenc Signal ) symbol in the 1 ms subframe in the respective subframes, then the RS in each subframe can be extracted.

In a practical application, the first stage power gain control module 50, the second stage power gain control module 51, the third stage power gain control module 52, the loop filter circuit 53, the first processing submodule 500, the first update The output sub-module 501, the second processing sub-module 510, the second update output sub-module 511, the third processing sub-module 520, and the third update output sub-module 521 may each be a central processing unit (CPU), or a digital signal. Processing (DSP, Digital Signal Processor), or Field Programmable Gate Array (FPGA), etc.; the CPU, DSP, and FPGA can be built in the base station.

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

The TD-LTE automatic gain control method provided by the embodiment of the present invention calculates the average power of the corresponding symbol in units of frame length, in units of half frame length, and in units of subframe length, respectively, according to the environmental characteristics of the three stages. By comparing the maximum average power value of one frame long symbol with the upper power limit and/or the lower power limit, the most reasonable power gain control value in the frequency sweep and PSS detection phase can be obtained; the average power of the semi-frame long RSS symbol and the SSS symbol is obtained. Comparing the value with the first target power value, the most reasonable power gain control value in the SSS detection and PBCH reading stages can be obtained; the downlink service can be obtained by comparing the average power value of the subframe RS symbol with the second target power value. channel The most reasonable power gain control value in the receiving phase; the embodiment of the present invention distinguishes the environmental characteristics of the three phases, and adopts different power gain control methods in each phase to improve the flexibility of power control.

The above is only the preferred embodiment of the present invention and is not intended to limit the scope of the present invention.

Claims

claims

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

In the frequency scanning and primary synchronization symbol PSS detection stages, the unit is frame length, in the secondary synchronization symbol SSS detection and physical broadcast channel PBCH reading stages, the unit is half frame length, and in the downlink service channel reception stage, the unit is subframe length. The average power of the corresponding symbol in each TD-LTE frame is compared with the power value and the second target power value to obtain the most reasonable power gain control value for each stage.

2. The TD-LTE automatic gain control method according to claim 1, wherein in the frequency 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 based on the comparison results. Output the power gain control value of the current TD-LTE frame at this stage to the SSS detection and PBCH reading stage, or proceed to the next stage. Processing of TD-LTE frames.

3. The TD-LTE automatic gain control method according to claim 1, wherein in the SSS detection and PBCH reading stages, the method includes:

Receive the power gain control value output in the frequency scanning and PSS detection stages, calculate the average power value of the current half-frame PSS symbol and SSS symbol based on the 5ms half-frame length of the TD-LTE frame, and use the calculated current half-frame PSS symbol, The SSS symbol average power value is compared with the first target power value, and based on the comparison result, the power gain control value of the current half frame in this stage is updated and output to the downlink traffic channel reception stage, and the next half frame is processed at the same time, or the next half frame is processed. deal with.

4. The TD-LTE automatic gain control method according to claim 1, wherein in the downlink traffic channel reception stage, the method includes:

Receive the power gain control value output from the SSS detection and PBCH reading stages. Taking the 1ms subframe length of the TD-LTE frame as the unit, the average power value of the current subframe reference signal RS symbol will be calculated, and Compare the calculated average power value of RS symbols of the current subframe with the second target power value, update the power gain control value of the current subframe at this stage according to the comparison result and notify the current user equipment UE, or perform the next subframe deal with.

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

Receive the power gain range marked by the RF chip, and divide the power gain range into multiple sub-segments on average to obtain the average power gain change;

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, 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 less than the lower power 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, the initial power gain value of the first frame is updated as the initial power gain value of the second frame;

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

Using the average power calculation method, calculate the average power value of each symbol within 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 upper power limit, the initial power gain value of the second frame is updated 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 less than the lower power limit, the initial power gain value of the second frame is updated 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 The initial power gain value of the second frame is used as the initial power gain value of the third frame;

Output the second frame maximum average power value as the second frame power gain control value 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 includes:

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

According to the average power calculation method, the average power of the first half-frame PSS symbol and SSS symbol in the frequency domain is calculated, and filtered 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;

Determine 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 is equal to When the power value is not equal to the first target power value, the first half-frame average power gain value is updated as the current half-frame power gain control value, output to the downlink traffic channel reception stage, and at the same time enters the second half-frame of the current frame to process;

The process of entering the second half frame of the current frame is:

According to the average power calculation method, the average power of the second half-frame PSS symbol and SSS symbol in the frequency domain is calculated, and filtered through the loop filter circuit. At this time, the average power value is used as the second half-frame average power value;

Determine whether the second half-frame average power value is equal to the first target power value. When the second half-frame average power value is equal to the first target power value, enter the third half-frame processing of the current frame; when the second half-frame average When the power value is not equal to the first target power value, the second half-frame average power gain value is updated as the current half-frame power gain control value, output to the downlink traffic channel reception stage, and at the same time enters the third half-frame of the current frame to process; And so on, until all half frames received by the UE are completed.

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

The downlink traffic channel receiving stage receives the current half-frame power gain control value output by the PSS detection and PBCH reading stage, performs bandwidth variation 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;

According to the average power calculation method, the average power of the first subframe RS symbol in the frequency domain is calculated. 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. 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, the first subframe average power gain value is updated as the current subframe power gain control value and notified to the current UE; at the same time, the second subframe processing of the current half frame is entered;

The process of entering the second subframe of the current half frame is:

According to the average power calculation method, the average power of the second subframe RS symbol in the frequency domain is calculated. 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 second subframe average power value is equal to the second target power value. When the second subframe average power value 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, the second subframe average power gain value is updated as the current subframe power gain control value and notified to the current UE; at the same time, the third subframe processing of the current half frame is entered;

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

8. A TD-LTE automatic gain control device, the device 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 configured to 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 combine the maximum average power value with the preset power upper limit and/ Or the power lower limit is compared to obtain the most reasonable power gain control value in the frequency scanning and primary synchronization symbol PSS detection stages;

The second stage power gain control module is configured to calculate the average power value of the current half-frame PSS symbol and SSS symbol based on the 5ms half-frame length of the TD-LTE frame, and use the calculated current half-frame PSS symbol, The average power value of the SSS symbol is compared with the preset first target power value to obtain the most reasonable power gain control value in the secondary synchronization symbol SSS detection and physical broadcast channel PBCH reading stages;

The third stage power gain control module is configured to calculate the average power value of the current subframe reference signal RS symbol based on the 1ms subframe length of the TD-LTE frame, and use the calculated average power value of the current subframe RS symbol The power value is compared with the preset second target power value to obtain the most reasonable power gain control value in the downlink service channel reception stage;

The loop filter circuit is configured to filter 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 according to claim 8, wherein the first stage power gain control module includes: a first processing sub-module and a first update output sub-module; wherein,

The first processing sub-module is configured to calculate the average power value of each symbol of the current TD-LTE frame in units of 10ms frame length, and compare the average power value of each symbol of 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 upper power limit and/or the lower power limit; The first update output sub-module is configured to update the current TD-LTE frame power gain control value based on the comparison result as the initial power gain value of the next frame and send it to the first processing sub-module, or output the current TD-LTE frame power gain control value. 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 sub-module is also configured to receive the After the first update output sub-module initial power gain value of the next frame, processing of the next frame begins.

10. The TD-LTE automatic gain control device according to claim 8, wherein the second stage power gain control module includes: a second processing sub-module and a second update output sub-module; the second processing sub-module , configured to calculate the current half-frame PSS symbol and SSS symbol average power value 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;

The second update output sub-module is configured to update the current half-frame power gain value based on the comparison result and output it to the third-stage power gain control module, and at the same time notify the second processing sub-module to process the next half-frame. Or notify the second processing sub-module to process the next half-frame; the second processing sub-module is further configured to start processing the next half-frame after receiving the notification sent by the second update output sub-module.

11. The TD-LTE automatic gain control device according to claim 8, wherein the third stage power gain control module includes: a third processing sub-module and a third update output sub-module; wherein,

The third processing sub-module is configured to calculate the current subframe reference signal RS symbol average power value, and compare the calculated current subframe RS symbol average power value with the second target power value; the third update output sub-module Module configured to update the current subframe power gain control value based on the comparison result and notify the current UE, and simultaneously notify the third processing submodule to perform next subframe processing, or notify the third processing submodule to perform next subframe processing. One subframe processing;

The third processing sub-module is also configured to receive the information sent by the third update output sub-module. After the notification, start processing the next subframe,