CN105898873A - Data frame distribution method and device and data transmission method and device - Google Patents

Abstract

Embodiments of the present invention provide a method and device for allocating data frames and a method and device for data transmission. The method for allocating data frames includes: calculating the sensing frame, transmission frame, and backoff frame of the current frame period according to the previous frame period. Slot length, assign the sensing frame and transmission frame of the current frame period to the LTE user terminal within the coverage of the base station of the LTE system; when it is detected that the LTE user terminal has successfully completed data transmission, the backoff frame of the current frame period is allocated to the LTE user The terminal makes it back off the channel according to the backoff frame. The method and device for allocating data frames and the method and device for data transmission provided by the embodiments of the present invention add a backoff frame to the frame of the existing LTE system, and improve the performance of the WLAN system by reducing the channel occupancy rate of the LTE system. The channel occupancy and throughput enable the WLAN system and the LTE system to coexist well, and also improve the utilization of unlicensed frequency bands.

Description

Data frame allocation method and device, and data transmission method and device

technical field

The present invention relates to the technical field of wireless communication, in particular to a data frame allocation method and device, and a data transmission method and device.

Background technique

With the explosive development of mobile Internet and high-bandwidth data services, mobile data traffic, the number of mobile terminals, and the number of mechanical terminal connections have shown a blowout growth.

The prior art discloses a LAA (Licensed-Assisted Access) technology, which utilizes the LTE system to access unlicensed frequency bands in a WLAN (Wireless Local Area Networks, wireless local area network) system environment. Add more available spectrum to meet user needs.

The access process of the existing LTE (Long Term Evolution, long-term evolution technology) system unlicensed frequency band is mainly carried out through the way of listening first and speaking. Usually, the frame of the LTE system includes two parts: the sensing frame and the transmission frame. The sensing frame is used for Perceive whether the channel of the current unlicensed frequency band is in an idle state, and if it is in an idle state, the LTE system accesses the channel and transmits data through transmission frames.

However, since the WLAN system complies with the MAC (Media Access Control, Media Access Control) layer protocol, it occupies the channel in a contention manner with conflict avoidance, while the LTE system does not have a conflict avoidance mechanism. When the WLAN system and the LTE system coexist, The WLAN system will frequently back off, while the LTE system will occupy the channel for a long time, resulting in a significant drop in the channel occupancy rate and throughput of the WLAN system, reducing the channel utilization of the unlicensed frequency band.

Contents of the invention

The purpose of the embodiments of the present invention is to provide a method and device for allocating data frames and a method and device for data transmission, so as to solve the coexistence problem of WLAN system and LTE system and improve the utilization rate of unlicensed frequency bands.

In order to achieve the above object, an embodiment of the present invention provides a method for allocating data frames, which is applied to a controller in a base station of an LTE system, and the method includes:

According to the time slot lengths of the sensing frame, transmission frame and backoff frame of the current frame period calculated in the previous frame period, the sensing frame and transmission frame of the current frame period are allocated to the LTE users within the coverage of the LTE system base station Terminal; wherein, the perception frame is used by the LTE user terminal to detect whether the channel is idle at the current moment; the transmission frame is used by the LTE user terminal to perform data transmission;

When it is detected that the LTE user terminal successfully completes the data transmission, the back-off frame of the current frame period is allocated to the LTE user terminal, so that it backs off from the channel according to the back-off frame.

Preferably, the time slot lengths of the perception frame, transmission frame and backoff frame of the current frame period are calculated by the following steps:

Calculate the time slot lengths of the sensing frame, the transmission frame and the backoff frame of the current frame period according to the channel occupancy information of the unlicensed frequency band collected in the first predetermined time before the current moment and the channel occupancy information stored in history.

Preferably, the channel occupancy information includes: the number of attempts to access the LTE system, the number of successful accesses to the LTE system, the number of contention points in the WLAN system, and the throughput of the contention points in the WLAN system;

The calculation of the time slot length of the backoff frame of the current frame period according to the channel occupancy information of the unlicensed frequency band collected within the first predetermined time before the current moment and the historically stored channel occupancy information includes:

Calculate the probability of successful access according to the number of attempted access times of the LTE system and the number of times of successful access to the LTE system in the unlicensed frequency band within the first predetermined time period collected before the current moment;

Searching for the number of WLAN system contention points matching the successful access probability in the historically stored channel occupancy information according to the successful access probability;

Find the throughput of WLAN system contention points with the same number as the number of WLAN system contention points according to the number of WLAN system contention points, and the throughput of the number of WLAN system contention points plus one The throughput of WLAN system contention points under the same number;

According to the formula calculating the slot length of the backoff frame;

Wherein, T is the time slot length of the frame period, P _suc is the successful access probability, n is the number of WLAN system contention points matching the successful access probability P _suc , and n+1 is the The number of WLAN system contention points matched by the successful access probability P _suc plus one, S _n is the throughput of the WLAN system contention points under the same number as the number n of the WLAN system contention points, S _n+1 is the throughput of the WLAN system contention points under the same number n+1 as the number n+1 of the WLAN system contention points matching the successful access probability P _suc .

Preferably, the number of WLAN system contention points and the throughput of the WLAN system contention points are information received in real time from a WLAN system base station.

Preferably, the calculation of the time slot length of the sensing frame of the current frame period according to the channel occupancy information of the unlicensed frequency band collected within the first predetermined time before the current moment and the channel occupancy information stored in history includes:

Establish a binary hypothesis model for the situation that the channel in the unlicensed frequency band is in the idle state and the non-idle state;

Calculate the detection probability and the false alarm probability of the LTE user terminal according to the binary hypothesis model;

Calculate the average throughput of the LTE system when the channel is in an idle state and the average throughput of the LTE system when the channel is in a non-idle state according to the detection probability and the false alarm probability;

According to the formula and calculating the time slot length T _sense of the sensing frame through a traversal algorithm;

Wherein, T _back is the time slot length of the backoff frame of the current frame period, T is the time slot length of the frame period, R ₀ is the average throughput of the LTE system when the channel is in an idle state, and R ₁ is all The average throughput of the LTE system when the channel is in a non-idle state, _Pd is the detection probability, is the detection probability threshold.

Preferably, the calculation of the time slot length of the transmission frame of the current frame period according to the channel occupancy information of the unlicensed frequency band collected within the first predetermined time before the current moment and the historically stored channel occupancy information includes:

Calculate the time slot length T _trans of the transmission frame according to the formula T _trans =TT _back -T _sense ;

Wherein, T _sense is the time slot length of the sensing frame of the current frame period, T _back is the time slot length of the backoff frame of the current frame period, and T is the time slot length of the frame period.

Preferably, the method also includes:

When it is detected that the LTE user terminal has not successfully completed the data transmission, the sensing frame and the transmission frame of the next frame period are allocated to the LTE user terminal.

The embodiment of the present invention also provides a data transmission method, which is applied to an LTE user terminal, and the method includes:

Obtain the sensing frame and transmission frame allocated by the controller in the LTE system base station; the sensing frame and transmission frame are when the controller calculates the time slot length of the sensing frame, transmission frame and backoff frame of the current frame period, assigned to LTE user terminals;

Detect whether the channel is in an idle state according to the perception frame;

When detecting that the channel is in an idle state according to the perception frame allocated by the controller in the LTE system base station, access the channel, and perform data transmission according to the transmission frame allocated by the controller;

After the data transmission is successfully completed, a backoff frame assigned by the controller is received, and the channel is backed off according to the backoff frame.

The embodiment of the present invention also provides a device for distributing data frames, which is applied to a controller in a base station of an LTE system, and the device includes:

The first perception frame and transmission frame allocation module is used to allocate the perception frame and transmission frame of the current frame period according to the time slot lengths of the perception frame, transmission frame and backoff frame of the current frame period calculated in the previous frame period To the LTE user terminal within the coverage of the LTE system base station; wherein, the sensing frame is used by the LTE user terminal to detect whether the channel is in an idle state at the current moment; the transmission frame is used for the LTE user terminal to perform data transmission;

The backoff frame allocation module is configured to allocate a backoff frame of the current frame period to the LTE user terminal after detecting that the LTE user terminal successfully completes data transmission, so that it backs off from the channel according to the backoff frame.

The embodiment of the present invention also provides a data transmission device, which is applied to an LTE user terminal, and the device includes:

The perception frame and transmission frame acquisition module are used to obtain the perception frame and transmission frame allocated by the controller in the base station of the LTE system; the perception frame and transmission frame are the perception frame and transmission frame calculated by the controller in the current frame period When the time slot length of the frame and backoff frame is allocated to the LTE user terminal;

A channel detection module, configured to detect whether the channel is in an idle state according to the perception frame;

The data transmission module is used to access the channel when detecting that the channel is in an idle state according to the sensing frame allocated by the controller in the LTE system base station, and perform data transmission according to the transmission frame allocated by the controller;

The channel back-off module is configured to receive a back-off frame assigned by the controller after successfully completing the data transmission, and back off the channel according to the back-off frame.

The method and device for allocating data frames and the method and device for data transmission provided by the embodiments of the present invention add a backoff frame to the frame of the existing LTE system, and improve WLAN by reducing the channel occupancy rate of the LTE system. The channel occupancy and throughput of the system enable the WLAN system and the LTE system to coexist well, and also improve the utilization rate of the unlicensed frequency band. Of course, implementing any product or method of the present invention does not necessarily need to achieve all the above-mentioned advantages at the same time.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is the first flow chart of the data frame distribution method provided by the embodiment of the present invention;

FIG. 2 is a schematic diagram of a coexistence time frame between a WLAN system and an LTE system provided by an embodiment of the present invention;

Fig. 3 is the second flow chart of the data frame allocation method provided by the embodiment of the present invention;

FIG. 4 is a flowchart of a method for calculating a time slot length of a backoff frame in a method for allocating data frames provided by an embodiment of the present invention;

FIG. 5 is a flowchart of a method for calculating a time slot length of a perception frame in a data frame allocation method provided by an embodiment of the present invention;

FIG. 6 is a flowchart of a data transmission method provided by an embodiment of the present invention;

FIG. 7 is a first structural schematic diagram of a device for distributing data frames provided by an embodiment of the present invention;

FIG. 8 is a second structural schematic diagram of a data frame distribution device provided by an embodiment of the present invention;

FIG. 9 is a schematic structural diagram of a backoff frame time slot length calculation unit in a data frame allocation device provided by an embodiment of the present invention;

FIG. 10 is a schematic structural diagram of a perceptual frame time slot length calculation unit in a data frame allocation device provided by an embodiment of the present invention;

FIG. 11 is a schematic structural diagram of a data transmission device provided by an embodiment of the present invention.

detailed description

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Embodiment one

As shown in Figure 1, it is the first flow chart of the data frame allocation method provided by the embodiment of the present invention. This method is applied to the controller in the base station of the LTE system, and its principle is: through the frame of the existing LTE system A back-off frame is added so that when it coexists with the WLAN system, it backs off the channel after completing a data transmission, so as to increase the chance of the WLAN system occupying the channel for data transmission, and improve the utilization rate of the channel as a whole. The allocation methods for this data frame include:

S110. According to the time slot lengths of the sensing frame, transmission frame and backoff frame of the current frame period calculated in the previous frame period, allocate the sensing frame and transmission frame of the current frame period to the LTE system base station within the coverage An LTE user terminal; wherein, the perception frame is used by the LTE user terminal to detect whether the channel is in an idle state at the current moment; the transmission frame is used by the LTE user terminal to perform data transmission.

Specifically, the frame period of the LTE system is the time slot length (indicated by T) of a complete frame, and the time slot length T of the frame period can be set according to different protocol versions (such as the MAC layer protocol), or it can be set by itself , such as 20 ms. The frame cycle of the LTE system is divided into three parts: sensing frame, transmission frame and backoff frame in turn. Among them, the sensing frame is used by the LTE user terminal to detect whether the current unlicensed frequency band channel is idle, and the transmission frame is used by the LTE user terminal to transmit data. , the backoff frame is used for the LTE user terminal to back off the channel. The time slot lengths of the sensing frame, transmission frame and backoff frame (defining the time slot length of the sensing frame as T _sense , the time slot length of the transmission frame as T _trans and the time slot length of the backoff frame as T _back ) can be fixedly set, or can be set according to Different situations are specifically set by calculation. For example, the time slot length T _sense of the sense frame is 1 millisecond, the time slot length T _trans of the transmission frame is 10 milliseconds, and the time slot length T _back of the backoff frame is 9 milliseconds. Preferably, before allocating the sensing frame, transmission frame and backoff frame in the current frame period, the controller in the base station of the LTE system has already calculated the specific lengths of these three frames, and each frame period needs to be calculated, so the current The calculation process of the frame period needs to be completed within the previous frame period.

Further, when the LTE user terminal enters the coverage area of the LTE system base station, the LTE system base station will allocate the sensing frame and the transmission frame in the frame period of the LTE user terminal, and the LTE user terminal detects whether the channel of the current unlicensed frequency band is In the idle state, if the current channel is in the idle state, the LTE user terminal accesses the channel and performs data transmission; if it detects that the current channel is in a non-idle state, the LTE user terminal does not transmit data on the transmission frame.

It is worth noting that when the LTE user terminal detects the channel state according to the sensing frame, there is a certain false alarm probability, that is, whether the detection result of the LTE user terminal is correct. For example, if the LTE user terminal detects that the current channel is in an idle state, but the channel is actually in a non-idle state, the detection result this time is an error result, and the LTE user terminal will not perform data transmission on the transmission frame. In this embodiment, the false alarm probability is negatively correlated with the time slot length of the sensing frame, and the longer the time slot length of the sensing frame, the smaller the false alarm probability.

S120. After detecting that the LTE user terminal successfully completes the data transmission, assign the backoff frame of the current frame period to the LTE user terminal, so that it backoffs from the channel according to the backoff frame.

Specifically, the successful completion of data transmission above means that the LTE user terminal has successfully completed the data transmission of the time slot length of the transmission frame. When the LTE user terminal perceives that the current channel is not idle or perceives that the current channel is idle When in a non-idle state (that is, a false alarm), data transmission cannot be successfully completed.

When the controller in the base station of the LTE system detects that the LTE user terminal has successfully completed data transmission, it allocates a backoff frame in the current frame period of the LTE user terminal, and the LTE user terminal backs off from the channel according to the backoff frame, while the WLAN user terminal can Detection and data transmission are performed within the time slot length of the backoff frame, which increases the chance of the WLAN system occupying a channel, and enables the WLAN system and the LTE system to coexist well.

As shown in FIG. 2 , it is a schematic diagram of a coexistence time frame between a WLAN system and an LTE system provided by an embodiment of the present invention. Among them, the upper figure shows the frame structure of the WLAN system, and the lower figure shows the frame structure of the LTE system, and the horizontal axis is time. According to the success of the user terminal channel state detection, the base station of the LTE system perceives different ways to allocate the sensing frame (the time slot length is T _sense ) and the transmission frame (the time slot length is T ) to the user terminal in the frame period (the time slot length is T sense ). slot length T _trans ) and a backoff frame (slot length T _back ).

When the LTE user terminal detects that the current channel is idle through the sensing frame, it accesses the channel and performs data transmission through the transmission frame. After the transmission frame ends, the LTE user terminal backs off the channel according to the backoff frame (this is a successful detection). During the backoff time, the WLAN user terminal can perform normal detection and data transmission. When the LTE system backoff frame time ends and the user terminal performs the next frame period detection, if it detects that the current channel is not idle (WLAN user terminal access channel) or If a false alarm is detected, the LTE user terminal cannot perform data transmission until the end of the transmission frame and enters another frame period (this is a detection failure).

The data frame allocation method provided by the embodiment of the present invention adds a backoff frame to the frame of the existing LTE system, and improves the channel occupancy rate and throughput of the WLAN system by reducing the channel occupancy rate of the LTE system, so that The WLAN system and the LTE system can coexist well, and at the same time, the channel utilization rate of the unlicensed frequency band channel is improved.

Embodiment two

As shown in Figure 3, the second flow chart of the data frame allocation method provided by the embodiment of the present invention can be regarded as an expansion of the method shown in Figure 1 above, and the method includes:

S310. Calculate the time slot lengths of the sensing frame, transmission frame and backoff frame of the current frame period according to the channel occupancy information of the unlicensed frequency band collected in the first predetermined time before the current moment and the channel occupancy information stored in history.

Specifically, the first predetermined duration is a preset time interval for collecting channel occupancy information of the unlicensed frequency band, which can be set freely. For example, a slot length of ten frame periods or a slot length of twenty frame periods, etc.

In this embodiment, the channel occupancy information includes the number of attempts to access the LTE system, the number of successful accesses to the LTE system, the number of contention points in the WLAN system, the throughput of the contention points in the WLAN system, and the like.

Among them, the number of LTE system access attempts is the number of times the LTE user terminal detects the channel, which includes the total number of times the LTE user terminal detects that the current channel is idle and non-idle; the number of successful accesses to the LTE system is the number of times the LTE user terminal detects the current channel The number of successful data transmissions after accessing the channel in an idle state; the number of WLAN system contention points is the number of WLAN user terminals within the coverage of the LTE system base station within the first predetermined period of time, that is, the number of WLAN user terminals competing for channels with LIT user terminals The number of WLAN user terminals; the throughput of the contention point of the WLAN system is the throughput of the WLAN user terminals within the coverage of the base station of the LTE system within the first predetermined period of time.

It is worth noting that, since there may be WLAN user terminals entering and exiting the coverage area of the base station of the LTE system within the first predetermined period of time, which may also cause changes in throughput, the number of WLAN system contention points and The throughput of the contention points of the WLAN system is actually two average values to represent the average change of the number of contention points of the WLAN system and the throughput information of the contention points of the LAN system within the first predetermined time period.

Further, the number of WLAN system contention points and the throughput of the WLAN system contention points are information received in real time from the base station of the WLAN system. Since the controller in the LTE system base station cannot directly collect data information in the WLAN system, the controller in the LTE system base station needs to send instructions to the controller in the WLAN system base station to collect these data, and the controller in the WLAN system base station The number of WLAN system contention points and the throughput of the WLAN system contention points are sent to the controller in the LTE system base station in real time through the WLAN system base station, so as to meet the requirements of the controller in the LTE system base station.

Specifically, the historically stored channel occupancy information is the channel occupancy information stored in the controller in the base station of the LTE system (the number of attempted accesses to the LTE system, the number of successful accesses to the LTE system, the number of WLAN system contention points, and the number of WLAN system contention points). The throughput of grabbing points), the storage method can be fixed storage, such as storing the channel occupancy information of a certain two months; Access times and LTE system successful access times, the number of WLAN system contention points and the throughput of WLAN system contention points received by the controller in the LTE system base station in real time from the WLAN system base station.

In this embodiment, this step is a step of calculating the time slot lengths of the sensing frame, transmission frame and backoff frame of the current frame period in S110 above.

Specifically, the current moment is defined as the moment used to calculate the current frame period. According to the deduction of time, the current moment must be a certain moment in the previous frame period. In this embodiment, the collected channel occupancy information within the first predetermined period of time before the current moment can be compared with the historically stored channel occupancy information, and statistical methods of big data (such as neural network algorithms, linear regression, etc.) Algorithm or clustering algorithm, etc.), judge the state of the current channel, calculate the time slot length of the perception frame, transmission frame and backoff frame of the new frame period, and use the new frame period as the current period.

S320. According to the time slot lengths of the sensing frame, transmission frame and backoff frame of the current frame period calculated in the previous frame period, allocate the sensing frame and transmission frame of the current frame period to the LTE system base station coverage An LTE user terminal; wherein, the perception frame is used by the LTE user terminal to detect whether the channel is in an idle state at the current moment; the transmission frame is used by the LTE user terminal to perform data transmission.

In this embodiment, this step S320 is the same as the above S110.

S330. After detecting that the LTE user terminal successfully completes the data transmission, allocate the backoff frame of the current frame period to the LTE user terminal, so that it backoffs from the channel according to the backoff frame.

In this embodiment, this step S330 is the same as the above S120.

S340. After detecting that the LTE user terminal has not successfully completed data transmission, allocate a sensing frame and a transmission frame for the LTE user terminal in a next frame period.

As shown in Figure 2, if the controller in the base station of the LTE system detects that the LTE user terminal has not successfully completed data transmission, it will not allocate the backoff frame of the current frame period to the LTE user terminal, but directly allocate it to the next frame of the LTE user terminal. The perception frame and the transmission frame of the frame period, so that the LTE user terminal can directly enter the next frame period after the transmission frame of the current frame period ends, which can save the channel corresponding to the time slot length of the backoff frame.

The data frame allocation method provided by the embodiment of the present invention compares the collected channel occupancy information within the first predetermined time before the calculation time of the current frame period with the historically stored channel occupancy information, and calculates the current frame period. The perception frame, transmission frame and backoff frame solve the coexistence problem of the WLAN system and the LTE system, and at the same time adapt to the real-time changing channel state, further improving the utilization rate of the channel.

Embodiment three

As shown in Figure 4, it is a flow chart of the calculation method of the backoff frame time slot length in the data frame allocation method provided by the embodiment of the present invention, and this method can be regarded as a specific implementation of the backoff frame calculation method in S310 above method, which includes:

S410. Calculate the probability of successful access according to the collected number of LTE system access attempts and the number of LTE system successful access times in the unlicensed frequency band within the first predetermined time period before the current moment.

Specifically, let the number of LTE system access attempts in the unlicensed frequency band within the first predetermined time before the current moment be N _attempt , and the number of successful LTE system accesses be N _suc , then the successful access probability The calculation formula is

For example, if the number of attempts to access the LTE system N _attempt =10, and the number of successful accesses to the LTE system N _suc =8, the probability of successful access

S420. Search for the number of WLAN system contention points matching the successful access probability in the historically stored channel occupancy information according to the successful access probability.

In this embodiment, due to the huge amount of data in the historically stored channel occupancy information, the number of contention points in different WLAN systems will correspond to a certain probability of successful access, and the probability of successful access will fluctuate within a certain data range. The successful access probability can be regarded as the average value of the data range. For example, assuming that the number n of contention points in the WLAN system is 9, the successful access probability Between 79% and 81%, it can be regarded as Similarly, assuming the successful access probability Find the and The number n of matching WLAN system contention points is 9. The matching method may be a clustering algorithm, a neural network algorithm, or a linear regression algorithm in statistics.

In this embodiment, if the number of attempted accesses to the LTE system N _attempt =5 and the number of successful accesses to the LTE system N _suc =4, the successful access probability Then the number n of contention points in the WLAN system is also 9.

S430. Find the throughput of WLAN system contention points with the same number as the number of WLAN system contention points according to the number of WLAN system contention points, and increase the throughput with the number of WLAN system contention points. The throughput of the contention points of the WLAN system under the same number of ones.

Specifically, since the number of contention points of the WLAN system within the coverage of the base station of the LTE system changes with time, the throughput of the contention points of the WLAN system will also change continuously. The number of contention points of a certain fixed WLAN system, They all correspond to the throughput of a WLAN system contention point, and the throughput of the WLAN system contention point will fluctuate within a certain range.

In this embodiment, the throughput S _n of the WLAN system contention points matching the number n of WLAN system contention points is searched in the historically stored channel occupancy information, and the number of WLAN system contention points plus one The throughput S _{n+1 of WLAN system contention points under the same number of n+1} . Normally, as the number of contention points in the WLAN system increases, the throughput of the contention points in the WLAN system will decrease, that is, S _n+1 <S _n .

S440, according to the formula The time slot length T _back of the backoff frame is calculated.

Specifically, assume that the probability of a successful access transmission is Then the probability of a failed access attempt is And the duration of a failed access attempt is TT _back . In a successful access attempt, assuming that the time slot length of the perception frame is much smaller than the time slot length of the transmission frame and the backoff frame, the time slot length of the transmission frame The length T _trans ≈TT _back . The channel occupancy rate of the LTE system in the unlicensed band can be calculated as:

$\mathrm{<span\; class="notranslate">\; \&Phi;</span>}<span\; class="notranslate">\; =</span>\frac{{\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; P</span>}}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; u</span>}\mathrm{<span\; class="notranslate">\; c</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; )</span>}{{\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; P</span>}}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; u</span>}\mathrm{<span\; class="notranslate">\; c</span>}}\mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; P</span>}}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; u</span>}\mathrm{<span\; class="notranslate">\; c</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; .</span>$

In this embodiment, in order to ensure that the channel occupancy rate of the WLAN system cannot be too low, the channel occupancy rate of the LTE system needs to have an upper limit, and is selected according to the following formula:

$\mathrm{<span\; class="notranslate">\; \&Phi;</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>\frac{{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}}{\mathrm{<span\; class="notranslate">\; no</span>}}<span\; class="notranslate">\; \&le;</span>\frac{{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}}{\mathrm{<span\; class="notranslate">\; no</span>}}<span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}}{\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}$

The left side of the above formula Indicates the reduction in the average throughput of the original n WLAN competing nodes after the LTE user terminal enters the coverage of the LTE system base station; the right side of the formula Indicates that after adding one WLAN contending node, the throughput of the original n WLAN contending nodes is reduced. This formula means that adding an LTE user terminal to the original n WLAN contending nodes will result in a lower decrease in average throughput than adding a WLAN contending node.

According to the above two formulas, we get

Wherein, T is the time slot length of the frame period, P _suc is the successful access probability, n is the number of WLAN system contention points matching the successful access probability P _suc , and n+1 is the The number of WLAN system contention points matched by the successful access probability P _suc plus one, S _n is the throughput of the WLAN system contention points under the same number as the number n of the WLAN system contention points, S _n+1 is the throughput of the WLAN system contention points under the same number n+1 as the number n+1 of the WLAN system contention points matching the successful access probability P _suc .

The time slot length calculation method of the backoff frame in the data frame allocation method provided by the embodiment of the present invention, according to the successful access probability within the first predetermined time length, searches for the number of WLAN system contention points in the historically stored channel occupancy information information, and then search for the throughput of WLAN system contention points under the same number as the number of WLAN system contention points, and the throughput under the same number as the number of WLAN system contention points plus one The WLAN system competes for the throughput of the point, and calculates the time slot length of the backoff frame of the current frame period according to the information, thereby improving the channel occupancy rate of the WLAN system and improving the channel utilization rate.

Embodiment Four

As shown in FIG. 5 , it is a flow chart of the calculation method of the time slot length of the perceptual frame in the data frame allocation method provided by the embodiment of the present invention. This method can be regarded as a specific implementation of the perceptual frame calculation method in S310 above. method, which includes:

S510. Establish a binary hypothesis model for the situation that the channel in the unlicensed frequency band is in an idle state and a non-idle state.

Specifically, it is assumed that s(n) and u(n) represent WLAN system signal and additive white Gaussian noise respectively. When a WLAN system signal uses the channel for data transmission, it is detected by the LTE user terminal and is sampled at the sampling frequency f _s , so within the time slot length T _sense of the sensing frame, the number of samples sampled is T _sense f _s .

For the LTE user terminal in the sensing frame, its received signal y(n) obeys a binary hypothesis testing model (this is the prior art), as follows:

$\mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; u</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; :</span>{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}\\ \mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; u</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; :</span>{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\end{array}\right.$

Among them, H ₀ means that the WLAN system is in an idle state, and H ₁ means that the WLAN system is in a non-idle state. Assume that u(n) is an independent and identically distributed Gaussian random variable with a mean of 0 and a variance of obey the distribution same assumption And independent of u(n).

S520. Calculate the detection probability and false alarm probability of the LTE user terminal according to the binary hypothesis model.

Specifically, the meaning of the detection probability is to judge whether the LTE user terminal performs detection. Because the channel WLAN system is in an idle state or a non-idle state (in this embodiment only the WLAN system and the LTE system are considered, so here the WLAN system is in an idle state or a non-idle state means that the channel is in an idle state or a non-idle state), LTE All user terminals can perform channel detection, so when the WLAN system is in an idle state, LTE user terminals have a certain probability to perform channel detection.

In this embodiment, according to the formula of the above-mentioned binary hypothesis testing model, the detection probability of the LTE user terminal can be calculated when the WLAN system is in a non-idle state and the threshold value is greater than ε (this is the prior art)

${\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; PR</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ></span>\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}<span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; Q</span>}<span\; class="notranslate">\; (</span><span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}{{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; u</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; \&gamma;</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; \&gamma;</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}\sqrt{\frac{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; e</span>}\mathrm{<span\; class="notranslate">\; no</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; e</span>}}{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ;</span>$

Among them, Q(x) is the Q function, ε is the threshold value, and γ is the signal-to-noise ratio.

At the same time, when the WLAN system is in an idle state and the threshold is greater than ε, the false alarm probability of the LTE user terminal (this is the prior art)

${\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; f</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; PR</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; T</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ></span>\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}<span\; class="notranslate">\; |</span>{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; Q</span>}<span\; class="notranslate">\; (</span><span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}{{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; u</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>\sqrt{\frac{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; e</span>}\mathrm{<span\; class="notranslate">\; no</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; e</span>}}{\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; .</span>$

S530. Calculate the average throughput of the LTE system when the channel is in an idle state and the average throughput of the LTE system when the channel is in a non-idle state according to the detection probability and the false alarm probability.

Specifically, it is assumed that C ₀ is the throughput of the LTE system when the channel is in an idle state, and its occurrence probability is (1-P _f )P(H ₀ ). C ₁ is the throughput of the LTE system when the channel is not idle, and its occurrence probability is (1-P _d )P(H ₁ ); among them, P(H ₀ ) and P(H ₁ ) can be obtained by the following formula ( This is prior art)

in, is the transmission probability of each station in a time slot, p is the collision probability, W is the minimum contention window of the WLAN system, n is the number of contention points in the WLAN system, and m is the maximum backoff order.

Finally, the average throughput of the LTE system R ₀ =C ₀ (1-PfPH0 when the channel is in an idle state is calculated, and the average throughput of the LTE system R1=C11-PdPH1 when the WLAN system is in a non-idle state.

S540, according to the formula And calculate the time slot length T _sense of the sensing frame through a traversal algorithm.

In this embodiment, from the average throughput of the LTE system R ₁ =C ₁ (1-P _d )P(H ₁ ) when the channel is in a non-idle state, it can be known that when the detection probability P _d is too small, the average throughput of the LTE system The amount R ₁ will become larger. In order to avoid the throughput of the LTE system from being too large, the detection probability P _d needs to be greater than a certain detection probability threshold which is

At the same time, in order to ensure that the LTE user terminal achieves a small false alarm probability when detecting the channel, it is necessary to increase the time slot length T _sense of the sensing frame as much as possible. Therefore, the calculation formula for the average sensing throughput of the objective function LTE system The value of T _sense in should reach the maximum as far as possible.

It can be seen from the above formula that the objective function is a convex function relative to T _sense , and there is at least one maximum value on the objective function curve, and the maximum value can be calculated by traversal algorithm within the range of T _sense , and it can be used as the optimal T _sense ;

Wherein, T _back is the time slot length of the backoff frame of the current frame period (which can be solved according to the above-mentioned embodiment ₎ , T is the time slot length of the frame period, and R is the LTE system when the channel is in an idle state The average throughput of , R ₁ is the average throughput of the LTE system when the channel is in a non-idle state, P _d is the detection probability, is the detection probability threshold.

The time slot length calculation method of the perception frame in the data frame allocation method provided by the embodiment of the present invention establishes a binary hypothesis model for the channel state in the idle state or in the non-idle state, and calculates the detection probability, false alarm probability, The average throughput of the LTE system when the channel is in an idle state and the average throughput of the LTE system when the channel is in a non-idle state, and determine the objective function of the average perceived throughput of the LTE system, according to the lower limit of the predefined detection probability, use the ergodic method Compute the slot length of the optimal perceptual frame in the objective function. On the premise of ensuring the detection probability of the LTE user terminal, the method searches for the optimal time slot length of the sensing frame and reduces the false alarm probability.

Further, the calculation of the time slot length of the transmission frame of the current frame period according to the channel occupancy information of the unlicensed frequency band collected in the first predetermined time before the current moment and the historically stored channel occupancy information includes:

Calculate the time slot length T _trans of the transmission frame according to the formula T _trans =TT _back -T _sense ;

Wherein, T _sensr is the time slot length of the sensing frame of the current frame period, T _back is the time slot length of the backoff frame of the current frame period, and T is the time slot length of the frame period.

In this embodiment, since the time slot length of the frame period is a fixed value, and the frame period is divided into sensing frame, transmission frame and backoff frame in sequence, the time slot length of the sensing frame and the backoff frame The time slot length can determine the time slot length of the transmission frame.

Embodiment five

As shown in FIG. 6, it is a flowchart of a data transmission method provided by an embodiment of the present invention. The method is applied to an LTE user terminal, which includes:

S610, acquire the sensing frame and transmission frame assigned by the controller in the base station of the LTE system; the sensing frame and transmission frame are the time slot lengths of the sensing frame, transmission frame and backoff frame calculated by the controller in the current frame period , allocated to LTE user terminals.

Specifically, when an LTE user terminal enters the coverage area of an LTE system base station, the controller in the LTE system base station will calculate the time slot lengths of sensing frames, transmission frames, and backoff frames in the frame period (each frame's The calculation method is the same as the above-mentioned embodiment, and will not be repeated here) and allocated to the sensing frame and transmission frame of the LTE user terminal.

S620. Detect whether the channel is in an idle state according to the perception frame.

Specifically, the LTE user terminal detects whether the channel is in an idle state according to the time slot length of the perception frame. In this embodiment, the longer the detection time of the LTE user terminal is, the lower the false alarm probability is.

S630. When it is detected that the channel is in an idle state according to the sensing frame allocated by the controller in the base station of the LTE system, access the channel, and perform data transmission according to the transmission frame allocated by the controller.

Specifically, if it is detected that the current channel is in an idle state, the LTE user terminal accesses the channel and performs data transmission according to the transmission frame; if it is detected that the current channel is in a non-idle state, the user terminal will not perform data transmission until the transmission Frame ends.

S640. After successfully completing the data transmission, receive a backoff frame assigned by the controller, and backoff from the channel according to the backoff frame.

Specifically, when the base station controller of the LTE system detects that the LTE user terminal has successfully completed data transmission, it will allocate a backoff frame for the current frame period to the LTE user terminal, and the LTE user terminal will back off from the channel according to the backoff frame until the backoff frame ends and enter the next channel. One frame period, and the WLAN user terminal can perform normal detection and data transmission within the time slot length of the backoff frame of the LTE system. Therefore, the backoff frame of the LTE system provides a chance for the WLAN user terminal to occupy the channel.

Further, if the base station controller of the LTE system detects that the LTE user terminal has not successfully completed data transmission, after the transmission frame of the current frame period ends, the backoff frame of the current frame period of the LTE user terminal is not allocated, but is directly allocated to the LTE user terminal The perception frame and transmission frame of the next frame period.

In the data transmission method provided by the embodiment of the present invention, the LTE user terminal will actively retreat out of the channel after the data transmission is completed, and the time slot length of the backoff frame is vacated for the WLAN user terminal to perform detection and data transmission, which increases the channel occupancy of the WLAN system The rate solves the coexistence problem of the WLAN system and the LTE system, and also improves the channel utilization rate of the unlicensed frequency band.

Embodiment six

As shown in FIG. 7, it is a schematic diagram of the first structure of the data frame allocation device provided by the embodiment of the present invention. The device is applied to the controller in the base station of the LTE system, and is used to execute the above-mentioned method shown in FIG. 1, which includes The first perception frame and transmission frame allocation module 7100 and the backoff frame allocation module 7200 .

The first perceptual frame and transmission frame allocation module 7100 is configured to allocate the perceptual frame and transmission frame of the current frame period according to the time slot lengths of the perceptual frame, transmission frame and backoff frame of the current frame period calculated in the previous frame period Assigned to LTE user terminals within the coverage of the LTE system base station; wherein, the sensing frame is used by the LTE user terminal to detect whether the channel is idle at the current moment; the transmission frame is used by the LTE user terminal for data transmission.

The back-off frame allocation module 7200 is configured to allocate a back-off frame of the current frame period to the LTE user terminal after detecting that the LTE user terminal successfully completes data transmission, so that it backs off from the channel according to the back-off frame.

The device for distributing data frames provided by the embodiments of the present invention adds a backoff frame to the frame of the existing LTE system, and improves the channel occupancy and throughput of the WLAN system by reducing the channel occupancy rate of the LTE system, so that The WLAN system and the LTE system can coexist well, and at the same time, the channel utilization rate of the unlicensed frequency band channel is improved.

Embodiment seven

As shown in FIG. 8 , it is a second structural schematic diagram of a device for allocating data frames provided by an embodiment of the present invention. The device is used to execute the method shown in FIG. 3 above, which includes a first perception frame and transmission frame allocation module 7100 , a backoff frame allocation module 7200, a time slot length calculation module 7300, and a second perception frame and transmission frame allocation module 7400.

The time slot length calculation module 7300, configured to calculate the sensing frame, transmission frame and backoff of the current frame period according to the channel occupancy information of the unlicensed frequency band collected within the first predetermined time before the current moment and the channel occupancy information stored in history The slot length of the frame.

Specifically, the channel occupancy information includes: the number of attempted accesses to the LTE system, the number of successful accesses to the LTE system, the number of contention points in the WLAN system, and the throughput of the contention points in the WLAN system. Wherein, the number of WLAN system contention points and the throughput of the WLAN system contention points are information received in real time from a WLAN system base station.

The first perceptual frame and transmission frame allocation module 7100 is configured to allocate the perceptual frame and transmission frame of the current frame period according to the time slot lengths of the perceptual frame, transmission frame and backoff frame of the current frame period calculated in the previous frame period Assigned to LTE user terminals within the coverage of the LTE system base station; wherein, the sensing frame is used by the LTE user terminal to detect whether the channel is idle at the current moment; the transmission frame is used by the LTE user terminal for data transmission.

The back-off frame allocation module 7200 is configured to allocate a back-off frame of the current frame period to the LTE user terminal after detecting that the LTE user terminal successfully completes data transmission, so that it backs off from the channel according to the back-off frame.

The second sensing frame and transmission frame allocation module 7400 is configured to allocate the sensing frame and transmission frame of the next frame period to the LTE user terminal after detecting that the LTE user terminal has not successfully completed data transmission.

Specifically, the time slot length calculation module 7300 includes: a perception frame time slot length calculation unit 7310 , a transmission frame time slot length calculation unit 7320 and a backoff frame time slot length calculation unit 7330 .

The perceptual frame time slot length calculation unit 7310 is configured to calculate the perceptual frame of the current frame period according to the channel occupancy information of the unlicensed frequency band collected within the first predetermined time before the current time and the historically stored channel occupancy information. slot length.

The transmission frame time slot length calculation unit 7320 is configured to calculate the length of the transmission frame of the current frame period according to the channel occupancy information of the unlicensed frequency band collected within the first predetermined time before the current moment and the channel occupancy information stored in history. slot length.

The backoff frame time slot length calculation unit 7330 is configured to calculate the backoff frame of the current frame period according to the channel occupancy information of the unlicensed frequency band collected within the first predetermined time before the current moment and the channel occupancy information stored in history slot length.

The data frame allocation device provided by the embodiment of the present invention compares the collected channel occupancy information within the first predetermined time period before the calculation time of the current frame period with the historically stored channel occupancy information, and calculates the current frame period. The perception frame, transmission frame and backoff frame solve the coexistence problem of the WLAN system and the LTE system, and at the same time adapt to the real-time changing channel state, further improving the utilization rate of the channel.

Embodiment eight

As shown in FIG. 9 , it is a schematic structural diagram of a backoff frame time slot length calculation unit in the data frame allocation device provided by the embodiment of the present invention, and the unit is used to execute the above-mentioned method shown in FIG. 4 .

The backoff frame time slot length calculation unit 7330 includes: a successful access probability generation subunit 7331, a WLAN system contention point number generation subunit 7332, a WLAN system contention point throughput generation subunit 7333, and a backoff frame time slot length Subunit 7334 is generated.

The successful access probability generation subunit 7331 is configured to calculate the successful access probability according to the collected LTE system access attempts and LTE system successful access times in the unlicensed frequency band within the first predetermined time before the current moment.

The subunit 7332 for generating the number of WLAN system contention points is configured to search for the number of WLAN system contention points matching the successful access probability in the historically stored channel occupancy information according to the successful access probability.

The WLAN system contention point throughput generation subunit 7333 is configured to search for the throughput of WLAN system contention points under the same number as the number of WLAN system contention points according to the number of WLAN system contention points, and Throughput of WLAN system contention points under the same number as the number of WLAN system contention points plus one.

Back off frame slot length generation subunit 7334, used for according to the formula Calculate the time slot length T _back of the backoff frame.

Wherein, T is the time slot length of the frame period, P _suc is the successful access probability, n is the number of WLAN system contention points matching the successful access probability P _suc , and n+1 is the The number of WLAN system contention points matched by the successful access probability P _suc plus one, S _n is the throughput of the WLAN system contention points under the same number as the number n of the WLAN system contention points, S _n+1 is the throughput of the WLAN system contention points under the same number n+1 as the number n+1 of the WLAN system contention points matching the successful access probability P _suc .

The backoff frame time slot length calculation unit in the data frame distribution device provided by the embodiment of the present invention searches for the information on the number of WLAN system contention points in the historically stored channel occupation information according to the successful access probability within the first predetermined time length , and further search for the throughput of WLAN system contention points under the same number as the number of WLAN system contention points, and the WLAN under the same number as the number of WLAN system contention points plus one The system competes for the throughput of the point, and calculates the time slot length of the backoff frame of the current frame period according to the information, thereby improving the channel occupancy rate of the WLAN system and improving the channel utilization rate.

Embodiment nine

As shown in FIG. 10 , it is a schematic structural diagram of the perceptual frame time slot length calculation unit in the data frame allocation device provided by the embodiment of the present invention, and the unit is used to execute the above-mentioned method shown in FIG. 5 .

The perceptual frame slot length calculation unit 7310 includes: binary hypothesis model generation subunit 7311, detection probability and false alarm probability generation subunit 7312, LTE system average throughput generation subunit 7313 and perceptual frame slot length generation subunit 7314.

The binary hypothesis model generation subunit 7311 is configured to establish a binary hypothesis model for the situation that the channel in the unlicensed frequency band is in an idle state and a non-idle state.

The detection probability and false alarm probability generating subunit 7312 is configured to calculate the detection probability and false alarm probability of the LTE user terminal according to the binary hypothesis model.

The LTE system average throughput generation subunit 7313 is used to calculate the average throughput of the LTE system when the channel is in an idle state and the average throughput of the LTE system when the channel is in a non-idle state according to the detection probability and the false alarm probability .

Perceptual frame time slot length generation subunit 7314, used for according to the formula And calculate the time slot length T _sense of the sensing frame through a traversal algorithm.

Wherein, T _back is the time slot length of the backoff frame of the current frame period, T is the time slot length of the frame period, R ₀ is the average throughput of the LTE system when the channel is in an idle state, and R ₁ is all The average throughput of the LTE system when the channel is in a non-idle state, _Pd is the detection probability, is the detection probability threshold.

The perceptual frame time slot length calculation unit in the data frame distribution device provided by the embodiment of the present invention establishes a binary hypothesis model for the channel state in the idle state or in the non-idle state, and calculates the detection probability, false alarm probability, channel The average throughput of the LTE system in the idle state and the average throughput of the LTE system in the non-idle state of the channel, and determine the objective function of the average perceived throughput of the LTE system, according to the lower limit of the predefined detection probability, use the ergodic method to calculate The slot length of the optimal perceptual frame in the objective function. On the premise of ensuring the detection probability of the LTE user terminal, the method searches for the optimal time slot length of the sensing frame and reduces the false alarm probability.

Embodiment ten

As shown in FIG. 11 , it is a schematic structural diagram of a data transmission device provided by an embodiment of the present invention. The device is applied to an LTE user terminal to execute the method shown in FIG. 6 above. The data transmission device includes: a perception frame and transmission frame acquisition module 1110 , a channel detection module 1120 , a data transmission module 1130 and a channel backoff module 1140 .

The perception frame and transmission frame acquisition module 1110 is used to obtain the perception frame and transmission frame allocated by the controller in the base station of the LTE system; the perception frame and transmission frame are the perception frame calculated by the controller in the current frame period, When the time slot length of the transmission frame and the backoff frame is allocated to the LTE user terminal;

A channel detection module 1120, configured to detect whether the channel is in an idle state according to the perception frame

The data transmission module 1130 is configured to access the channel when detecting that the channel is idle according to the sensing frame allocated by the controller in the base station of the LTE system, and perform data transmission according to the transmission frame allocated by the controller.

The channel back-off module 1140 is configured to receive a back-off frame assigned by the controller after successfully completing the data transmission, and back off the channel according to the back-off frame.

In the data transmission device provided by the embodiment of the present invention, the LTE user terminal will actively retreat out of the channel after the data transmission is completed, and the time slot length of the backoff frame is vacated for the WLAN user terminal to perform detection and data transmission, which increases the channel occupancy of the WLAN system The rate solves the coexistence problem of the WLAN system and the LTE system, and also improves the channel utilization rate of the unlicensed frequency band.

It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is a relationship between these entities or operations. There is no such actual relationship or order between them. Furthermore, the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus comprising a set of elements includes not only those elements, but also includes elements not expressly listed. other elements of or also include elements inherent in such a process, method, article, or device. Without further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article or apparatus comprising said element.

Each embodiment in this specification is described in a related manner, the same and similar parts of each embodiment can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and for relevant parts, refer to part of the description of the method embodiment.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present invention are included in the protection scope of the present invention.

Claims (10)

1. A method for distributing data frames, characterized in that, being applied to a controller in an LTE system base station, the method comprises: According to the time slot lengths of the sensing frame, transmission frame and backoff frame of the current frame period calculated in the previous frame period, the sensing frame and transmission frame of the current frame period are allocated to the LTE users within the coverage of the LTE system base station Terminal; wherein, the perception frame is used by the LTE user terminal to detect whether the channel is idle at the current moment; the transmission frame is used by the LTE user terminal to perform data transmission; When it is detected that the LTE user terminal successfully completes the data transmission, the back-off frame of the current frame period is allocated to the LTE user terminal, so that it backs off from the channel according to the back-off frame. 2. The method according to claim 1, wherein the time slot length of the perception frame, the transmission frame and the backoff frame of the current frame period is calculated by the following steps: Calculate the time slot lengths of the sensing frame, the transmission frame and the backoff frame of the current frame period according to the channel occupancy information of the unlicensed frequency band collected in the first predetermined time before the current moment and the channel occupancy information stored in history. 3. The method according to claim 2, wherein the channel occupancy information includes: the number of attempted accesses to the LTE system, the number of successful accesses to the LTE system, the number of contention points in the WLAN system, and the number of contention points in the WLAN system. throughput; The calculation of the time slot length of the backoff frame of the current frame period according to the channel occupancy information of the unlicensed frequency band collected within the first predetermined time before the current moment and the historically stored channel occupancy information includes: Calculate the probability of successful access according to the number of attempted access times of the LTE system and the number of times of successful access to the LTE system in the unlicensed frequency band within the first predetermined time period collected before the current moment; Searching for the number of WLAN system contention points matching the successful access probability in the historically stored channel occupancy information according to the successful access probability; Find the throughput of WLAN system contention points with the same number as the number of WLAN system contention points according to the number of WLAN system contention points, and the throughput of the number of WLAN system contention points plus one The throughput of WLAN system contention points under the same number; According to the formula calculating the slot length of the backoff frame; Wherein, T is the time slot length of the frame period, P _suc is the successful access probability, n is the number of WLAN system contention points matching the successful access probability P _suc , and n+1 is the The number of WLAN system contention points matched by the successful access probability P _suc plus one, S _n is the throughput of the WLAN system contention points under the same number as the number n of the WLAN system contention points, S _n+1 is the throughput of the WLAN system contention points under the same number n+1 as the number n+1 of the WLAN system contention points matching the successful access probability P _suc . 4. The method according to claim 3, wherein the number of WLAN system contention points and the throughput of the WLAN system contention points are information received in real time from a WLAN system base station. 5. The method according to claim 3, wherein the current frame period is calculated according to the channel occupancy information of the unlicensed frequency band collected within the first predetermined time before the current moment and the channel occupancy information stored in history The slot length of the perception frame, including: Establish a binary hypothesis model for the situation that the channel in the unlicensed frequency band is in the idle state and the non-idle state; Calculate the detection probability and the false alarm probability of the LTE user terminal according to the binary hypothesis model; Calculate the average throughput of the LTE system when the channel is in an idle state and the average throughput of the LTE system when the channel is in a non-idle state according to the detection probability and the false alarm probability; According to the formula and calculating the time slot length T _sense of the sensing frame through a traversal algorithm; Wherein, T _back is the time slot length of the backoff frame of the current frame period, T is the time slot length of the frame period, R ₀ is the average throughput of the LTE system when the channel is in an idle state, and R ₁ is all The average throughput of the LTE system when the channel is in a non-idle state, _Pd is the detection probability, is the detection probability threshold. 6. The method according to claim 4, wherein the current frame period is calculated according to the channel occupancy information of the unlicensed frequency band collected within the first predetermined time before the current moment and the channel occupancy information stored in history The slot length of the transmission frame, including: Calculate the time slot length T _trans of the transmission frame according to the formula T _trans =TT _back -T _sense ; Wherein, T _sense is the time slot length of the sensing frame of the current frame period, T _back is the time slot length of the backoff frame of the current frame period, and T is the time slot length of the frame period. 7. The method according to any one of claims 1-6, wherein the method further comprises: When it is detected that the LTE user terminal has not successfully completed the data transmission, the sensing frame and the transmission frame of the next frame period are allocated to the LTE user terminal. 8. A data transmission method, characterized in that being applied to an LTE user terminal, the method comprising: Obtain the sensing frame and transmission frame allocated by the controller in the LTE system base station; the sensing frame and transmission frame are when the controller calculates the time slot length of the sensing frame, transmission frame and backoff frame of the current frame period, assigned to LTE user terminals; Detect whether the channel is in an idle state according to the perception frame; When detecting that the channel is in an idle state according to the perception frame allocated by the controller in the LTE system base station, access the channel, and perform data transmission according to the transmission frame allocated by the controller; After the data transmission is successfully completed, a backoff frame assigned by the controller is received, and the channel is backed off according to the backoff frame. 9. A distribution device for a data frame, characterized in that it is applied to a controller in an LTE system base station, and the device includes: The first perception frame and transmission frame allocation module is used to allocate the perception frame and transmission frame of the current frame period according to the time slot lengths of the perception frame, transmission frame and backoff frame of the current frame period calculated in the previous frame period To the LTE user terminal within the coverage of the LTE system base station; wherein, the sensing frame is used by the LTE user terminal to detect whether the channel is in an idle state at the current moment; the transmission frame is used for the LTE user terminal to perform data transmission; The backoff frame allocation module is configured to allocate a backoff frame of the current frame period to the LTE user terminal after detecting that the LTE user terminal successfully completes data transmission, so that it backs off from the channel according to the backoff frame. 10. A data transmission device, characterized in that it is applied to an LTE user terminal, the device comprising: The perception frame and transmission frame acquisition module are used to obtain the perception frame and transmission frame allocated by the controller in the base station of the LTE system; the perception frame and transmission frame are the perception frame and transmission frame calculated by the controller in the current frame period When the time slot length of the frame and backoff frame is allocated to the LTE user terminal; A channel detection module, configured to detect whether the channel is in an idle state according to the perception frame; The data transmission module is used to access the channel when detecting that the channel is in an idle state according to the sensing frame allocated by the controller in the LTE system base station, and perform data transmission according to the transmission frame allocated by the controller; The channel back-off module is configured to receive a back-off frame assigned by the controller after successfully completing the data transmission, and back off the channel according to the back-off frame.