KR101355573B1 - Receive apparatus and transmission apparatus for data unit aggregation transmission system - Google Patents

Abstract

In the data unit combined transmission scheme, the present invention provides data transmission by optimally determining / modifying transmission parameters of the PHY layer and optimizing the length of the A-MSDU of the MAC layer so as to guarantee QoS corresponding to an application in use. A method of operating a receiver and a receiver of a data unit combined transmission system, and a transmitter and a transmitter of a data unit combined transmission system, which can maximize the efficiency and at the same time guarantee the packet loss probability of an application being used to ensure the quality of data communication. A method of operating a device is disclosed. In a data unit combined transmission service for transmitting a data frame including combined data in which data units are combined, a receiving apparatus of the present invention calculates signal-to-noise ratio information of the wireless channel using information of a wireless channel, and calculates the signal-to-noise ratio. Error probability is calculated for each candidate transmission parameter based on the information, and a candidate combined data size that satisfies a specific packet damage probability corresponding to a specific application is calculated for each error probability according to each candidate transmission parameter, thereby calculating the candidate probability. And selecting at least one of a specific transmission parameter having a maximum transmission efficiency and a specific combined data size among the transmission parameters and the respective candidate combined data sizes.

Description

RECEIVING AND TRANSMITTING DEVICE OF DATA UNIT TRANSMISSION TRANSFER SYSTEM {RECEIVE APPARATUS AND TRANSMISSION APPARATUS FOR DATA UNIT AGGREGATION TRANSMISSION SYSTEM}

The present invention relates to a receiving device and a transmitting device of a data unit combined transmission system, and more particularly, in a data unit combined transmission method for transmitting combined data combining a plurality of data units, guaranteeing QoS corresponding to an application in use. By optimally determining / modifying the transmission parameters of the PHY layer and optimizing the length of the A-MSDU of the MAC layer, it maximizes the data transmission efficiency and guarantees the packet loss probability of the application in use while also ensuring the quality of data communication. The present invention relates to a method of operating a receiver and a receiver of a data unit coupled transmission system, and a method of operating a transmitter and a transmitter of a data unit coupled transmission system.

According to IEEE 802.11n, an international standard of WLAN, an Aggregate-MAC Service Data Unit (A-MSDU) is adopted as a technology for improving the efficiency of the MAC layer for the data rate of the PHY layer.

The A-MSDU can reduce the overhead of the MAC-PHY layer by aggregating multiple MSDUs into one MSDU. Each MSDU constituting the A-MSDU has three field values: a destination address (DA), a sender address (SA), and a length. Each MSDU also has the same destination and TID (Traffic Identifier). However, in a poor radio channel environment, as the number of aggregated frames increases, the probability of packet corruption increases and the performance of A-MSDU decreases.

Therefore, an algorithm for determining a frame aggregation level in consideration of a radio channel situation should be considered. There are two conventional algorithms for this purpose.

First, the Optimal Frame Aggregation (OFA) algorithm is an aggregation method that maximizes this by using the saturated throughput model of DCF considering both packet loss due to collision and packet damage due to radio channel. Second, Frame-Aggregated Link Adaptation (FALA) algorithm uses the saturated throughput model of DCF in the same way as OFA method, but selects optimal transmission parameter considering AMC (Adaptive Modulation and Coding) at the same time, and the transmission parameter is given SINR and preset look-up This is determined by a table.

On the other hand, most applications have a Quality of Service (QoS) condition that must be satisfied.

However, the above-described OFA or FALA algorithm, which determines the frame aggregation level using the saturation throughput model of the DCF, has an advantage of maximizing transmission efficiency, but has a disadvantage in that the probability of resulting packet corruption is considerably high. The high probability of packet corruption has the problem of lowering the reception rate or increasing the probability of retransmission. That is, the A-MSDU scheme according to IEEE 802.11n has a problem in that its effectiveness is lost due to packet corruption in a wireless channel environment.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a data unit combined transmission service for transmitting a data frame including combined data in which data units are combined. The signal-to-noise ratio information of the wireless channel is calculated, an error probability is calculated for each candidate transmission parameter based on the signal-to-noise ratio information, and the candidate combined data size satisfying a specific packet damage probability corresponding to a specific application is calculated. A data unit combined transmission service for calculating at least one of the candidate transmission parameters and the respective candidate combined data sizes and selecting at least one of a specific transmission parameter having a maximum transmission efficiency and a specific combined data size among the candidate transmission parameters and the respective candidate combined data sizes. Receivers and receivers By providing a method of operation, to optimally determine / change the transmission parameters of the PHY layer and to optimize the length of the A-MSDU of the MAC layer to ensure the QoS corresponding to the application in use.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a specific transmission parameter selected by a receiving apparatus in a data unit combined transmission service for transmitting a data frame including combined data combining data units. And obtaining at least one of a specific combined data size and combining the two or more data units based on the specific combined data size to generate the combined data. In order to guarantee the QoS corresponding to the application in use, the transmission parameters of the PHY layer are optimally determined / modified and the length of the A-MSDU of the MAC layer is optimized.

A receiving apparatus of a data unit combined transmission system according to a first aspect of the present invention for achieving the above object is a data unit combined transmission system for transmitting a data frame including combined data combined data unit, the information of the radio channel A signal-to-noise ratio calculation unit configured to calculate signal-to-noise ratio information of the wireless channel by using a signal; An error probability calculator for calculating an error probability corresponding to each candidate transmission parameter based on the signal-to-noise ratio information; A size calculator for calculating candidate combined data sizes satisfying a specific packet damage probability corresponding to a specific application for each error probability according to each candidate transmission parameter; And an optimum information selection unit for selecting at least one of a specific transmission parameter having a maximum transmission efficiency and a specific combined data size among each candidate transmission parameter and each candidate combined data size.

Preferably, the size calculator is a combined data frame size calculator for calculating a candidate combined data frame size satisfying the specific packet damage probability for each error probability according to each candidate transmission parameter, and calculated for each error probability From each of the candidate combined data frame sizes, at least one of a data size per symbol and an overhead size according to each candidate transmission parameter corresponding to each error probability is removed, and each error probability according to each candidate transmission parameter is eliminated. A combined data size calculation unit for calculating the candidate combined data size may be included.

Preferably, the optimal information selecting unit transmits the candidate information based on at least one of the candidate combined data size, the number of spatial streams, and the transmission time required to transmit the data frame, calculated for each candidate transmission parameter. By calculating the efficiency, at least one of the candidate transmission parameter and the candidate combined data size corresponding to the maximum transmission efficiency among the calculated transmission efficiency may be selected.

Preferably, the method may further include an information storage unit that stores a predetermined packet damage probability corresponding to at least one application type.

Preferably, the apparatus may further include an information providing unit providing at least one of the selected specific transmission parameter and the specific combined data size to the transmission device.

A transmission apparatus of a data unit combined transmission system according to a second aspect of the present invention for achieving the above object is a data unit combined transmission system for transmitting a data frame including combined data combined data unit selected from the receiving apparatus An information acquisition unit for obtaining at least one of a specific transmission parameter and a specific combined data size; And a combined data generation unit for generating the combined data by combining two or more data units based on the specific combined data size.

Preferably, the data frame generation unit for generating a data frame including the combined data; And a data transmitter configured to perform at least one of channel encoding and modulation based on at least one of a code rate and a modulation degree included in the specific transmission parameter in response to the data frame.

Preferably, the data transmitter may transmit the data frame to the receiver through an antenna selected based on the number of spatial streams included in the specific transmission parameter.

According to a third aspect of the present invention, there is provided a method of operating a data unit combined transmission service according to a third aspect of the present invention. A signal-to-noise ratio calculation step of calculating signal-to-noise ratio information of the wireless channel using channel information; An error probability calculation step of calculating an error probability corresponding to each candidate transmission parameter based on the signal-to-noise ratio information; A size calculation step of calculating a candidate combined data size satisfying a specific packet damage probability corresponding to a specific application for each error probability according to each candidate transmission parameter; And an optimal information selection step of selecting at least one of a specific transmission parameter having a maximum transmission efficiency and a specific combined data size among each candidate transmission parameter and each candidate combined data size.

Preferably, the step of calculating the size, the combined data frame size calculation step of calculating the candidate combined data frame size that satisfies the specific packet damage probability for each error probability according to each candidate transmission parameter, and for each error probability From each of the calculated candidate combined data frame sizes, at least one of a data size and an overhead size per symbol according to each candidate transmission parameter corresponding to each error probability is removed, and the error probability according to each candidate transmission parameter is determined. A combined data size calculation step of calculating each candidate combined data size may be included.

Preferably, the selecting of the optimal information comprises: selecting at least one of the candidate combined data size, the number of spatial streams, and the transmission time required for transmitting the data frame, calculated for each candidate transmission parameter. By calculating the transmission efficiency, at least one of the candidate transmission parameter and the candidate combined data size corresponding to the maximum transmission efficiency among the calculated transmission efficiency may be selected.

Preferably, the method may further include storing a predetermined packet damage probability corresponding to each of the at least one application type.

Preferably, the method may further include providing at least one of the selected specific transmission parameter and the specific combined data size to the transmission apparatus.

According to a fourth aspect of the present invention, there is provided a method of operating a transmission unit for a data unit combined transmission service, comprising: a data unit combined transmission service for transmitting a data frame including combined data combined with a data unit; An information acquiring step of acquiring at least one of a specific transmission parameter and a specific combined data size selected by the apparatus; And a combined data step of generating the combined data by combining two or more data units based on the specific combined data size.

Preferably, the data frame generation step of generating a data frame including the combined data; And a data transmission step of performing at least one of channel encoding and modulation based on at least one of a code rate and a modulation degree included in the specific transmission parameter corresponding to the data frame.

Preferably, in the data transmission step, the data frame may be transmitted to the receiving apparatus through an antenna selected based on the number of spatial streams included in the specific transmission parameter.

Accordingly, according to the receiver and the transmitter and the operation method of each device of the data unit combined transmission system of the present invention, the error probability FEP corresponding to each candidate transmission parameter is calculated based on the signal-to-noise ratio (SINR) for the wireless channel. Optimal transmission parameter and combined data size that maximizes transmission efficiency among candidate transmission parameter and candidate combined data size by calculating link state and calculating candidate combined data size to guarantee specific packet damage probability corresponding to specific application in use In this case, the combined data unit (A-MSDU) combining the data units is generated on the basis of the optimal combined data size determined as described above, and the data frame including the combined data can be transmitted according to the optimal transmission parameter.

Therefore, according to the receiving device and the transmitting device of the data unit combined transmission system of the present invention and the operation method of each device, the transmission parameters of the PHY layer are optimally determined / modified and MAC can be guaranteed to ensure QoS corresponding to the application in use. By optimizing the length of the A-MSDU of the layer, it is possible to maximize the data transmission efficiency and ensure the packet loss probability of the application in use, thereby ensuring the quality of data communication.

1 is a block diagram showing a data unit combined transmission system according to a preferred embodiment of the present invention.
2 is a block diagram of a receiving apparatus according to a preferred embodiment of the present invention.
3 is a block diagram of a transmission apparatus according to a preferred embodiment of the present invention.
4 is a flowchart illustrating a control flow of a data unit combined transmission service according to a preferred embodiment of the present invention.
5 is a flowchart illustrating a method of operating a receiving apparatus according to a preferred embodiment of the present invention.
6 is a flowchart illustrating a method of operating a transmission apparatus according to a preferred embodiment of the present invention.
7 is an exemplary diagram illustrating a data frame structure including combined data (A-MSDU) to which the present invention is applied.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a data unit combined transmission system according to a preferred embodiment of the present invention, which includes a transmitting device 200 on a transmitting side for transmitting data and a receiving device 100 on a receiving side for receiving data.

Such a data unit combined transmission system preferably includes a wireless data communication system, in particular a wireless LAN system.

Thus, for example, the receiving apparatus 100 and the transmitting apparatus 200 of the data unit combined transmission system of the present invention are techniques for improving the efficiency of the MAC layer with respect to the data rate of the PHY layer, the data unit (MAC Service Data Unit) ) May be used to generate combined data, that is, Aggregate-MAC Service Data Unit (A-MSDU).

Thus, as shown in FIG. 7, the transmitter 200 aggregates a plurality of data units (MSDU) as each subframe to generate combined data (A-MSDU), and includes a combined data frame. It will be transmitted to the receiving apparatus 100.

At this time, each data unit has three field values: DA (Destination Address), SA (Sender Address), and Length. Each data unit also has the same destination and TID (Traffic Identifier).

The transmission device 200 may request optimal information from the reception device 100 to obtain an optimal combined data size and transmission parameter capable of guaranteeing a packet loss probability in a WLAN environment.

In this case, the optimal information request of the transmitter 200 may be transmitted to the receiver 100 through RTS or BlockAckReq using a High Throughput Control (HTC) field in the control wrapper frame.

Accordingly, the reception apparatus 100 having received the optimal information calculates signal-to-noise ratio information of the wireless channel using the information of the wireless channel.

Preferably, the reception apparatus 100 may calculate signal-to-interference plus noise ratio (SINR) of the radio channel, in particular, signal-to-interference plus noise ratio, using information on the radio channel such as an equivalent channel component and a transmission symbol. .

Then, the reception apparatus 100 calculates an error probability corresponding to each candidate transmission parameter based on the calculated signal-to-noise ratio information.

에 대응하여 오류확률 구체적으로는 FEP(First-event Error Probability)을 계산할 수 있다.That is, the reception apparatus 100, based on the calculated signal-to-noise ratio information, each candidate transmission parameter, specifically, each candidate AMCS parameter

In response to the error probability, specifically, first-event error probability (FEP) may be calculated.

Then, the reception apparatus 100 calculates a candidate combined data size that satisfies a specific packet damage probability corresponding to a specific application for each error probability according to each candidate transmission parameter.

That is, the reception device 100 preferably stores a specific packet damage probability that is preset in correspondence with at least one application type.

Accordingly, the reception apparatus 100 may recognize a specific application according to data communication with the transmission apparatus 200 and check a specific packet damage probability corresponding to the specific application.

Then, the reception apparatus 100 calculates the candidate combined data size satisfying the identified specific packet damage probability for each error probability according to each candidate transmission parameter.

Accordingly, the reception apparatus 100 obtains each candidate transmission parameter and each candidate combined data size calculated corresponding to each candidate transmission parameter.

Thereafter, the reception apparatus 100 selects at least one of the specific transmission parameter having the maximum transmission efficiency and the specific combined data size among the candidate transmission parameters and the candidate combined data sizes as the optimal information.

In addition, the reception apparatus 100 may provide the transmission apparatus 200 with the selected specific transmission parameter and the specific combined data size, that is, the optimal information. Here, the method of providing the optimal information by the reception apparatus 100 may be transmitted through the CTS or the BlockAck using the HTC field in the control wrapper frame as a reverse process for the optimal information request.

Accordingly, when the transmitter 200 obtains the optimal information requested from the receiver 100, that is, the specific transmission parameter and the specific combined data size, the transmitter 200 may select a plurality of data units MSDU as described above based on the obtained optimal information. Aggregation is performed as each subframe to generate combined data (A-MSDU), and a series of procedures for transmitting the data frame including the combined data to the receiving apparatus 100 are performed.

In other words, the transmission device 200 generates combined data by combining two or more data units based on the acquired optimal information, that is, a specific combined data size.

The transmitter 200 generates a data frame including the combined data, and encodes the channel based on at least one of code rate and modulation degree included in the optimal information acquired corresponding to the data frame, that is, the specific transmission parameter. And performing at least one of modulation and transmitting the data frame to the receiving apparatus 100 through an antenna selected based on the number of spatial streams included in a specific transmission parameter.

Hereinafter, the configuration of the receiver according to the present invention will be described in detail with reference to FIG. 2.

Receiving apparatus 100 according to the present invention, the signal-to-noise ratio calculation unit 110 for calculating the signal-to-noise ratio information of the radio channel using the information of the radio channel, and corresponding to each candidate transmission parameter based on the signal-to-noise ratio information An error probability calculator 120 for calculating an error probability and a candidate combined data size that satisfies a specific packet damage probability corresponding to a specific application for each error probability according to each candidate transmission parameter. And an optimal information selecting unit 160 for selecting at least one of a specific transmission parameter having a maximum transmission efficiency and a specific combined data size among each candidate transmission parameter and each candidate combined data size.

In addition, the reception apparatus 100 according to the present invention may further include an information storage unit 150 and an information providing unit 170.

The signal-to-noise ratio calculator 110 calculates signal-to-noise ratio information of the wireless channel using the information of the wireless channel. That is, the signal-to-noise ratio calculation unit 110 may calculate signal-to-interference plus noise ratio (SINR) of the radio channel signal-to-noise ratio information using information on the radio channel such as an equivalent channel component and a transmission symbol. .

For example, the signal-to-noise ratio calculation unit 110, after passing through a linear detector such as Zero-Forcing (ZF) or Minimum Mean-Squared Error (MMSE) applied to remove the interference of the MIMO channel, that is, Calculate the SINR.

)가 수신한 후처리 신호는, i번째 공간적 스트림(

) 그리고 n번째 subcarrier(

)에 대하여 수학식 1과 같이 주어진다.First, the j-th receiver 100 in I-BSS (Infrastructure Basic Service Set)

The post-processing signal received by) is the i-th spatial stream (

) And the nth subcarrier (

) Is given by Equation 1.

Equation 1

]ZF:

]

MMSE:

는 선형 검출기를 통과한 후의 등가 채널 성분을 나타내며,

는 전송 심볼을 나타내고 그 평균 파워는

이다. 여기서

는

의 심볼 에너지로서 i와 n에 상관없이 동일한 크기를 가지며

는 j번째 수신장치의 스트림 수를 나타낸다. 그리고

는 선형 검출기 이후의 간섭 및 잡음 성분을 나타낸다. 상기 수학식 1에 ZF과 MMSE 선형 검출기를 통과한 후의

에 대한 확률 분포가 주어져 있다. 여기서

는 선형 검출기 필터 행렬의 k번째 행을 나타내며,

은 선형 검출기 통과 전의 수신 잡음 성분에 대한 분산값을 나타낸다. here,

Represents the equivalent channel component after passing through the linear detector,

Represents the transmission symbol and its average power is

to be. here

The

Is the symbol energy of and has the same magnitude regardless of i and n

Denotes the number of streams of the j-th receiver. And

Denotes the interference and noise components after the linear detector. Equation 1 after passing through the ZF and MMSE linear detector

The probability distribution for is given. here

Represents the kth row of the linear detector filter matrix,

Denotes the variance of the received noise component before passing through the linear detector.

Accordingly, the signal-to-noise ratio calculation unit 110 of the j-th receiver 100 may calculate the post-processing SINR for the j-th receiver 100 through Equation 2 below for each spatial stream and frequency carrier (subcarrier). Can be.

(2)

에 대응하여 오류확률 구체적으로는 FEP(First-event Error Probability)을 계산할 수 있다.The error probability calculator 120 calculates an error probability corresponding to each candidate transmission parameter based on the calculated signal-to-noise ratio information. That is, the error probability calculator 120 calculates each candidate transmission parameter, specifically, each candidate AMCS parameter based on the calculated signal-to-noise ratio information.

In response to the error probability, specifically, first-event error probability (FEP) may be calculated.

에 대하여 아래 수학식3과 같은 상계를 갖는다For example, when the convolutional encoder adopted by the WLAN system is applied, the error probability FEP (First-event Error Probability) used when analyzing the code performance is represented by modulation rate (M), code rate (Rc), And a transmission parameter representing the number of spatial streams Ns, that is, an AMCS parameter.

With respect to Eq. (3)

Equation 3.

는 Hamming 거리,

는 자유 거리를 나타낸다.

는 전달 함수

에 대한 계수들이며 부호율 1/2 코드를 천공하여 얻은 부호율

에 따라 달라진다. 그리고

는 부호화열의 PEP(Pairwise Error Probability)를 나타내며 순시적인 SINR을 이용하여 아래와 같은 수학식4를 통해 계산될 수 있다.here

Hamming Street,

Represents the free distance.

Is a transfer function

Code rates obtained by puncturing the code rate 1/2 code

Depends on. And

Denotes PEP (Pairwise Error Probability) of the coded sequence and may be calculated using Equation 4 below using instantaneous SINR.

Equation 4.

In Equation 4, the PEP of the coded sequence uses Table 1 under the assumption that any symbol in the high signal-to-noise ratio region contains only one bit of error, and calculates a sample average of SINRs for each spatial stream and frequency carrier. Is calculated through. Table 1 shows the frequency probabilities corresponding to the squared Euclidean distance with one bit error at various modulation rates.

Basically, PEP is calculated in units of one OFDM symbol and can be represented as an average value of several OFDM symbols according to a period for measuring FER. For example, if FER is measured in 50 OFDM symbol periods and SINR information is given every 10 OFDM symbols, 5 PEPs are calculated and an average thereof is used. Note that the PEP measuring method of the present invention does not require statistical information about a channel, and can be used for all general channels.

M

BPSK {4} {One} QPSK {2} {One} 16-QAM {0.4, 3.6} {3/4, 1/4} 64-QAM {0.0952, 0.8571, 2.3810, 4.6667} {7/12, 1/4, 1/12, 1/12}

를 이용하여 수학식3을 통해, 각 후보 AMCS 파라미터

에 대응하여 오류확률 FEP을 계산할 수 있다.Therefore, the error probability calculation unit 120 is a PEP obtained by using Equation 4

By using Equation 3, each candidate AMCS parameter

The error probability FEP can be calculated accordingly.

On the other hand, it is possible to calculate the packet damage probability, PER (Packet Error Rate) for the convolutional encoder from the FEP obtained in Equation 3.

로 표시된 데이터 부분의 패킷 손상을 포함하며, 필요에 의하여 ACK와 같은 control 프레임에 대한 손상 확률도 포함될 수 있다, 하지만 데이터 부분과 비교하여 ACK의 길이는 매우 짧고 보다 낮은 변조도와 부호율이 사용되므로 패킷손상확률이 매우 낮아 무시될 수 있다. 따라서, 패킷손상확률은, 아래 수학식 5와 같이 계산될 수 있다.Here, the PER only considers packet damage due to the radio channel and does not include packet loss due to collision. More specifically, the packet damage probability is shown in FIG.

This includes packet corruption of the data portion denoted by, and may also include the probability of corruption for control frames, such as ACK, if necessary, but compared to the data portion, the length of the ACK is very short, and because the lower modulation and code rates are used, The probability of damage is very low and can be ignored. Therefore, the packet damage probability may be calculated as in Equation 5 below.

Equation 5.

The size calculator 140 calculates the candidate combined data size that satisfies the specific packet damage probability corresponding to the specific application for each error probability according to each candidate transmission parameter.

To this end, the information storage unit 150 stores a specific packet damage probability preset in correspondence with at least one application type.

That is, the information storage unit 150 may preset and store a specific packet damage probability to be guaranteed in response to various application types, for example, application types according to traffic types used, such as video traffic and real-time traffic.

Accordingly, the size calculator 140 may recognize the specific application according to data communication with the transmission apparatus 200 in the reception apparatus 100, and check the specific packet damage probability corresponding to the specific application.

에 따른 오류확률 FEP 별로 계산한다.Then, the size calculating unit 140 sets the candidate combined data size that satisfies the identified specific packet damage probability, that is, each candidate transmission parameter, that is, each candidate AMCS parameter.

Calculate the error probability according to FEP.

Specifically, the size calculating unit 140 calculates the combined data frame size calculating unit 130 that satisfies the candidate combined data frame size satisfying the specific packet damage probability for each error probability according to each candidate transmission parameter. And removing at least one of a data size per symbol and an overhead size according to each candidate transmission parameter corresponding to each error probability, from each candidate combined data frame size calculated for each error probability. A combined data size calculation unit 135 for calculating each candidate combined data size for each error probability according to the transmission parameter may be included.

Equation 6 associated with packet damage probability and error probability FEP can be obtained from Equation 5 described above.

Equation 6.

는 특정 어플리케이션에 대응하는 특정 패킷손상확률을 나타내며, 이는 상기 특정 어플리케이션이 요구하는 QoS의 척도가 될 수 있다.here

Denotes a probability of a specific packet corruption corresponding to a specific application, which may be a measure of QoS required by the specific application.

)을 만족시키는 후보 결합데이터프레임사이즈(

)를 상기 각 후보 전송파라미터(

)에 따른 각 오류확률

별로 계산한다.Therefore, the size calculating unit 140, in particular, the combined data frame size calculating unit 130, the specific packet damage probability (

Candidate combined data frame size satisfying

) For each of the candidate transmission parameters (

Error probability according to

Calculate poorly.

는 j번째 수신장치(100)에 해당되는 결합데이터프레임사이즈를 나타낸다(도 1 참조). here,

Denotes a combined data frame size corresponding to the j-th receiver 100 (see FIG. 1).

별로 계산된 각각의 후보 결합데이터프레임사이즈(

)로부터, 각 오류확률

에 대응되는 각 후보 전송파라미터(

)에 따른 심볼 당 데이터 사이즈 및 오버헤드 사이즈 중 적어도 하나를 제거하여, 아래의 수학식 7과 같이, 상기 각 후보 전송파라미터(

)에 따른 오류확률

별로 각 후보 결합데이터사이즈를 계산할 수 있다.Thereafter, the combined data size calculating unit 135 calculates the probability of each error.

Candidate combined data frame sizes

), Each error probability

Each candidate transmission parameter corresponding to

By removing at least one of the data size and the overhead size per symbol according to the following equation, each candidate transmission parameter (

Error probability according to)

For each candidate combined data size can be calculated for each.

Equation 7.

은 선택된 후보 전송파라미터(

)에 따른 OFDM 심볼 당 데이터 사이즈(혹은, 비트 수)를 나타내며,

는 도 1에 명시된 바와 같이 Service, MAC header, FCS, 그리고 Tail의 사이즈(혹은, 비트 수)의 합을 나타내는, 즉 오버헤드사이즈를 의미한다. 또한 IEEE 802.11n에 따르면, A-MSDU의 최대 길이

는 30712 bits(3839 bytes) 나 63480 bits (7935 bytes)로 제한되며, 이는 전송장치(200) 상의 버퍼 크기나, 구현 상 고려사항에 따라 선택될 수 있다. here,

Is the selected candidate transmission parameter (

) Represents the data size (or number of bits) per OFDM symbol,

As shown in FIG. 1, denotes the sum of the size (or number of bits) of the Service, MAC header, FCS, and Tail, that is, the overhead size. Also according to IEEE 802.11n, the maximum length of A-MSDU

Is limited to 30712 bits (3839 bytes) or 63480 bits (7935 bytes), which may be selected according to the buffer size on the transmitter 200 or implementation considerations.

에 대응되는 각 후보 전송파라미터(

) 별 각 후보 결합데이터사이즈(

)를 계산할 수 있다.Thus, the combined data size calculating unit 135, the probability of each error through the equation (7)

Each candidate transmission parameter corresponding to

Each candidate combined data size

) Can be calculated.

) 및 상기 각 후보 결합데이터사이즈(

) 중, 최대 전송효율을 갖는 특정 전송파라미터 및 특정 결합데이터사이즈 중 적어도 어느 하나를 선택한다.The optimal information selecting unit 160 stores each of the candidate transmission parameters (

) And each candidate combined data size (

), At least one of a specific transmission parameter having a maximum transmission efficiency and a specific combined data size is selected.

)에 대응하여 계산된 상기 각 후보 결합데이터사이즈(

), 공간 스트림 수(Ns), 상기 데이터프레임을 전송하는데 소요되는 전송시간 중 적어도 어느 하나를 기초로 상기 전송효율을 계산하여, 계산된 전송효율 중 최대 전송효율 계산 시 이용된 후보 전송파라미터 및 후보 결합데이터사이즈를 상기 특정 전송파라미터 및 상기 특정 데이터유닛사이즈로서 선택할 수 있다.That is, the optimum information selection unit 160 stores each candidate transmission parameter (

The candidate combined data size calculated according to

The candidate transmission parameters and candidates used for calculating the maximum transmission efficiency among the calculated transmission efficiencies by calculating the transmission efficiency based on at least one of the number of spatial streams (Ns) and the transmission time for transmitting the data frame. The combined data size can be selected as the specific transmission parameter and the specific data unit size.

For example, the optimal information selecting unit 160 may calculate the MAC throughput through Equation 8 below.

Equation 8.

와

에 의하여 결정된다. DCF 동작 시간은 DCF동작에 있어서의 전송성공, 전송실패, 그리고 Backoff 시간이 모두 고려될 수도 있으며, 편리에 의해 전송성공시간만을 고려할 수도 있다. 따라서, 수학식 8로부터 아래에 수학식 9에서 전송성공시간만을 고려할 경우의 MAC 처리량을 최대화하는 파라미터 선택 기준이 제시된다.Here, both data transfer amount and DCF operation time

Wow

. The DCF operation time may consider all of the transmission success, transmission failure, and backoff time in the DCF operation, and may only consider the transmission success time for convenience. Therefore, from Equation 8 below, parameter selection criteria for maximizing the MAC throughput when only the transmission success time is considered in Equation 9 are presented.

Equation 9.

는 PHY header의 전송 시간을 나타내며,

는

의 전송시간을 나타낸다. 결국 수학식 9를 통하여 도 1에서 A-MSDU가 포함된 MPDU의 전송효율을 최대화 하는 A-MSDU 길이 즉 최적의 결합데이터사이즈(

) 및 전송파라미터 즉 AMCS 파라미터 (

)가 선택됨을 의미한다.here

Indicates the transmission time of the PHY header,

The

Indicates the transmission time of. As a result, the length of the A-MSDU that maximizes the transmission efficiency of the MPDU including the A-MSDU in FIG.

) And transmission parameters, i.e. AMCS parameters (

) Is selected.

)과 전송파라미터 즉 AMCS 파라미터 (

)를 선택할 수 있다.Accordingly, the optimal information selecting unit 160 uses the optimal combined data size (maximum given MAC throughput used in calculating transmission efficiency through Equation 9 above).

) And transmission parameters, i.e. AMCS parameters (

) Can be selected.

)과 전송파라미터 (

)를 전송장치(200)로 제공한다.Then, the information providing unit 170, the optimum combined data size (selected by the optimum information selection unit 160 (

) And transmission parameters (

) Is provided to the transmission device 200.

In addition, Equation 9 may simply select the optimal combined data size and transmission parameters in consideration of only the transmission success time, and may be applied regardless of whether the RTS / CTS is used or not.

In this way, the reception apparatus 100, according to a request from the transmission apparatus 200 for data communication through the wireless LAN system, an error probability FEP corresponding to each candidate transmission parameter based on a signal-to-noise ratio (SINR) for the wireless channel. To determine the link state by calculating the link state, and to calculate the candidate combined data size that guarantees the probability of a specific packet damage corresponding to the specific application in use, and to optimize the transmission efficiency among the candidate transmission parameters and the candidate combined data size. The combined data size is determined and provided to the transmission device 200.

Hereinafter, the configuration of the transmission apparatus according to the present invention will be described in detail with reference to FIG. 3.

The transmission device 200 according to the present invention includes an information acquisition unit 210 for acquiring at least one of a specific transmission parameter selected from the reception device 100 and a specific combined data size, and 2 based on the specific combined data size. And a combined data generation unit 220 for combining the data units to generate combined data.

In addition, the transmission apparatus 200 according to the present invention may further include a data frame generation unit 230 and a data transmission unit 240.

The information acquisition unit 210 acquires at least one of a specific transmission parameter and a specific combined data size selected by the reception apparatus 100.

That is, the information acquisition unit 210 may request the optimal information from the reception apparatus 100 to obtain an optimal combined data size and transmission parameter capable of guaranteeing a packet loss probability in a WLAN environment. The receiver 100 may receive / acquire optimal information including the specific transmission parameter and the specific combined data size selected as described above.

The combined data generation unit 220 generates combined data by combining two or more data units based on a specific combined data size.

)를 기반으로 결합한 데이터유닛(MSDU) 갯수를 결정하여 결합할 수 있다.That is, the combined data generation unit 220, for the two or more data units (MSDU) delivered from the upper layer (data connection layer), the data unit for aggregation (aggregation) by checking the destination address DA, traffic type, etc. In this case, as shown in FIG. 7, a plurality of data units classified and classified are classified as optimum data obtained from the receiving apparatus 100, that is, the combined data size (

Based on the number of combined data units (MSDU) can be determined by combining.

)를 기반으로, 아래의 수학식 10에 따라 집합화/결합된 결합데이터(A-MSDU)를 얻을 수 있다.For example, the combined data generation unit 20 may determine the optimal information acquired from the reception apparatus 100, that is, the combined data size (

), The combined data (A-MSDU) can be obtained according to Equation 10 below.

Equation 10.

는 도 1에 나타내어진 바와 같이 A-MSDU 서브프레임에 해당하는 데이터유닛(MSDU)사이즈를 나타낸다. IEEE 802.11n에 따르면

의 최대 길이는 18432 bits (2304 bytes)로 제한된다. 그리고

는 각 MSDU를 구성하는 DA, SA, Length의 길이를 포함한다. 데이터 연결 계층에서 내려오는 데이터유닛에 따라 결합데이터(A-MSDU)의 최적 사이즈(길이)인

을 구성하는 프레임 집합화가 수행될 수 있다. here

1 shows a data unit (MSDU) size corresponding to an A-MSDU subframe as shown in FIG. 1. According to IEEE 802.11n

The maximum length of is limited to 18432 bits (2304 bytes). And

Includes lengths of DA, SA, and Length constituting each MSDU. The optimal size (length) of the combined data (A-MSDU) depends on the data units coming down from the data link layer.

Frame aggregation may be performed.

The combined data generation unit 220 preferably belongs to the media access control layer, that is, the MAC layer, and the service, MAC header, FCS, and the combined data (A-MSDU) as shown in FIG. After generating the combined data frame by adding the tail and delivers to the data frame generation unit 230.

The data frame generation unit 230 generates a data frame including the combined data transferred from the combined data generation unit 220.

That is, the data frame generation unit 230 generates a data frame by adding a PHY header to the combined data frame, as shown in FIG. 1, more precisely than the combined data transmitted from the combined data generation unit 220.

)에 포함된 부호율 및 변조도 중 적어도 어느 하나를 기초로 채널 부호화 및 변조 중 적어도 어느 하나를 수행한다.In addition, the data transmitter 240 corresponds to the data frame generated by the data frame generator 230, so that the optimal information acquired from the receiver 100, that is, the transmission parameter (

At least one of channel encoding and modulation is performed based on at least one of a code rate and a modulation degree included in the Rx.

)에 포함된 공간 스트림 수를 기초로 선택된 안테나를 통해 상기 데이터프레임을 수신장치(100)로 전송한다.In addition, the data transmission unit 240, the optimum information obtained from the receiving apparatus 100, that is, the transmission parameter (

The data frame is transmitted to the receiving apparatus 100 through the antenna selected based on the number of spatial streams included in the "

는, 변조도(M), 부호율(Rc), 그리고 공간적 스트림 수(Ns)를 포함한다.In other words, transmission parameters, i.e. AMCS parameters

Includes a modulation degree (M), a code rate (Rc), and a spatial stream number (Ns).

)에 포함된 변조도(M), 부호율(Rc)을 이용하여 이를 기반으로 데이터프레임생성부(230)에서 생성된 데이터프레임에 대응하여 채널 부호화 및 변조를 수행한다.Accordingly, the data transmission unit 240 performs channel encoding and modulation on the data frame for stable data transmission and speed improvement, so that the optimal information obtained from the reception apparatus 100, that is, the transmission parameter (

Channel coding and modulation are performed corresponding to the data frame generated by the data frame generation unit 230 based on the modulation degree M and the code rate Rc included in the Rx.

)에 포함된 공간 스트림 수를 기초로 전송 시 이용하는 안테나를 선택하고, 선택된 안테나를 통해 상기 데이터프레임을 수신장치(100)로 전송하게 된다.In addition, the data transmitter 240 transmits the data frame to the receiver 100, so that the optimal information acquired from the receiver 100, that is, the transmission parameter (

An antenna to be used for transmission is selected based on the number of spatial streams included in the), and the data frame is transmitted to the receiving apparatus 100 through the selected antenna.

The data frame generation unit 230 and the data transmission unit 240 preferably belong to a physical layer, that is, the PHY layer 250.

)를 이용하여 데이터 전송을 위한 PHY 계층의 MIMO BIC-OFDM 신호를 생성하는 것이다.For example, according to IEEE 802.11n, the PHY layer employs a Multiple-Input Multiple-Output Bit-Interleaved Coded Orthogonal Frequency Division Multiplexing (MIMO BIC-OFDM) technology for stable data transmission and speed improvement. Therefore, the data transmission unit 240 is optimized information, that is, the transmission parameter (

) To generate the MIMO BIC-OFDM signal of the PHY layer for data transmission.

As described above, a receiver and a transmitter supporting a data unit combined transmission service for jointly transmitting a data unit through a wireless LAN system correspond to each candidate transmission parameter based on a signal-to-noise ratio (SINR) for a wireless channel. Calculate the error probability FEP to find the link status, and calculate the candidate combined data size that guarantees the specific packet damage probability corresponding to the specific application in use, thereby maximizing the transmission efficiency among candidate transmission parameters and candidate combined data sizes. Determine the transmission parameters and the combined data size of the data, and generate the combined data (A-MSDU) combining the data units on the transmitter side based on the determined optimal combined data size, and transmit the data frame including the combined data optimally. It can be transmitted according to the parameter.

Accordingly, a receiver and a transmitter supporting a data unit combined transmission service for jointly transmitting data units through a WLAN system may optimally determine / transmit the transmission parameters of the PHY layer so as to guarantee QoS corresponding to an application in use. By changing and optimizing the length of the A-MSDU of the MAC layer, it is possible to maximize the data transmission efficiency while ensuring the packet loss probability of the application in use, thereby ensuring the quality of data communication.

Hereinafter, a data unit combined transmission service according to a preferred embodiment of the present invention will be described with reference to FIGS. 4 to 6. Here, for convenience of description, the components shown in FIGS. 1 to 3 will be described with reference to corresponding reference numerals.

First, the control flow of the data unit combined transmission service according to the preferred embodiment of the present invention will be described with reference to FIG. 4.

The transmitter 200 may request optimal information from the receiver 100 in order to obtain an optimal combined data size and transmission parameter capable of guaranteeing a packet damage probability in a WLAN environment (S10).

In this case, the optimal information request of the transmitter 200 may be transmitted to the receiver 100 through RTS or BlockAckReq using a High Throughput Control (HTC) field in the control wrapper frame.

Accordingly, the reception apparatus 100 having received the optimal information calculates signal-to-noise ratio information of the wireless channel using the information of the wireless channel (S20).

Preferably, the reception apparatus 100 may calculate signal-to-interference plus noise ratio (SINR) of the radio channel, in particular, signal-to-interference plus noise ratio, using information on the radio channel such as an equivalent channel component and a transmission symbol. .

Then, the reception apparatus 100 calculates an error probability corresponding to each candidate transmission parameter based on the calculated signal to noise ratio information (S30).

에 대응하여 오류확률 구체적으로는 FEP(First-event Error Probability)을 계산할 수 있다.That is, the reception apparatus 100, based on the calculated signal-to-noise ratio information, each candidate transmission parameter, specifically, each candidate AMCS parameter

In response to the error probability, specifically, first-event error probability (FEP) may be calculated.

In operation S40, the reception apparatus 100 calculates candidate combined data sizes satisfying a specific packet damage probability corresponding to a specific application for each error probability according to each candidate transmission parameter.

That is, the reception device 100 preferably stores a specific packet damage probability that is preset in correspondence with at least one application type.

Accordingly, the reception apparatus 100 may recognize a specific application according to data communication with the transmission apparatus 200 and check a specific packet damage probability corresponding to the specific application.

Then, the reception apparatus 100 calculates the candidate combined data size satisfying the identified specific packet damage probability for each error probability according to each candidate transmission parameter.

Accordingly, the reception apparatus 100 obtains each candidate transmission parameter and each candidate combined data size calculated corresponding to each candidate transmission parameter.

Thereafter, the reception apparatus 100 selects at least one of the specific transmission parameter having the maximum transmission efficiency and the specific combined data size among the candidate transmission parameters and the candidate combined data sizes as the optimal information (S50). .

In addition, the reception apparatus 100 may provide the transmission apparatus 200 with the selected specific transmission parameter and the specific combined data size, that is, the optimal information (S60). Here, the method of providing the optimal information by the reception apparatus 100 may be transmitted through the CTS or the BlockAck using the HTC field in the control wrapper frame as a reverse process for the optimal information request.

Accordingly, when the transmitter 200 obtains the optimal information requested from the receiver 100, that is, the specific transmission parameter and the specific combined data size, the transmitter 200 may select a plurality of data units MSDU as described above based on the obtained optimal information. Aggregation is performed as each subframe to generate combined data (A-MSDU), and a series of procedures for transmitting the data frame including the combined data to the receiving apparatus 100 are performed.

In other words, the transmitter 200 generates combined data by combining two or more data units based on the acquired optimal information, that is, a specific combined data size (S70).

In addition, the transmission apparatus 200 generates a data frame including the combined data (S80), and based on at least one of the code rate and modulation degree included in the optimal information acquired corresponding to the data frame, that is, the specific transmission parameter. At least one of raw channel encoding and modulation is performed, and the data frame is transmitted to the receiving apparatus 100 through an antenna selected based on the number of spatial streams included in a specific transmission parameter (S90).

Hereinafter, a method of operating a receiver according to a preferred embodiment of the present invention will be described with reference to FIG. 5.

The operation method of the receiving apparatus 100 according to the present invention stores a predetermined packet damage probability corresponding to at least one application type (S110).

That is, the operation method of the reception apparatus 100 according to the present invention receives a predetermined packet damage probability to be guaranteed in response to various application types, for example, application types according to traffic types used, such as video traffic and real-time traffic. Can be stored.

The operation method of the reception apparatus 100 according to the present invention receives an optimal information request from the transmission apparatus 200 to obtain an optimal combined data size and transmission parameter capable of guaranteeing a packet damage probability in a wireless LAN environment. (S120).

Accordingly, in the operation method of the reception apparatus 100 according to the present invention, signal-to-noise ratio information of the wireless channel is calculated using the information of the wireless channel (S130). That is, in the method of operating the receiver 100 according to the present invention, signal-to-noise ratio information of a wireless channel is specifically SINR (Signal-to-Interference plus Noise Ratio) using information of a wireless channel such as an equivalent channel component and a transmission symbol. ) Can be calculated.

For example, the operation method of the receiver 100 according to the present invention passes through a linear detector such as zero-forcing (ZF) or minimum mean-squared error (MMSE) applied to remove interference of the MIMO channel. Calculate signal-to-noise ratio information, i.e., SINR.

More specifically, in the method of operating the reception apparatus 100 according to the present invention, the j-th reception is performed through the following Equation 2 for each spatial stream and the frequency carrier (subcarrier) through Equations 1 and 2 described above. The post-processing SINR for the device 100 can be calculated.

에 대응하여 오류확률 구체적으로는 FEP(First-event Error Probability)을 계산할 수 있다.The operation method of the reception apparatus 100 according to the present invention calculates an error probability corresponding to each candidate transmission parameter based on the calculated signal-to-noise ratio information (S140). That is, in the operation method of the reception apparatus 100 according to the present invention, each candidate transmission parameter, specifically, each candidate AMCS parameter is based on the calculated signal-to-noise ratio information.

In response to the error probability, specifically, first-event error probability (FEP) may be calculated.

를 이용하여 전술의 수학식3을 통해, 각 후보 AMCS 파라미터

에 대응하여 오류확률 FEP을 계산할 수 있다.More specifically, the operation method of the receiving apparatus 100 according to the present invention is a PEP obtained by using the above equation (4)

By using the above equation (3), each candidate AMCS parameter

The error probability FEP can be calculated accordingly.

In the operation method of the reception apparatus 100 according to the present invention, a candidate combined data size that satisfies a specific packet damage probability corresponding to a specific application is calculated for each error probability according to each candidate transmission parameter (S150 and S160).

In detail, in the method of operating the reception apparatus 100 according to the present invention, the reception apparatus 100 may recognize a specific application according to data communication with the transmission apparatus 200 and identify a specific packet damage probability corresponding to the specific application. have.

에 따른 오류확률 FEP 별로 계산한다.In addition, in the method of operating the reception apparatus 100 according to the present invention, the candidate combined data size that satisfies the identified specific packet damage probability is determined by each candidate transmission parameter, that is, each candidate AMCS parameter.

Calculate the error probability according to FEP.

Specifically, the operation method of the reception apparatus 100 according to the present invention calculates the candidate combined data frame size satisfying the specific packet damage probability for each error probability according to each candidate transmission parameter (S150). .

In addition, in the operation method of the reception apparatus 100 according to the present invention, from the candidate combined data frame size calculated for each error probability, the data size per symbol according to each candidate transmission parameter corresponding to each error probability And eliminating at least one of the overhead sizes, and calculating each candidate combined data size for each error probability according to each candidate transmission parameter (S160).

)을 만족시키는 후보 결합데이터프레임사이즈(

)를 상기 각 후보 전송파라미터(

)에 따른 각 오류확률

별로 계산한다.For example, the operation method of the receiving apparatus 100 according to the present invention, according to the above Equation 6, the probability of the specific packet damage (

Candidate combined data frame size satisfying

) For each of the candidate transmission parameters (

Error probability according to

Calculate poorly.

별로 계산된 각각의 후보 결합데이터프레임사이즈(

)로부터, 각 오류확률

에 대응되는 각 후보 전송파라미터(

)에 따른 심볼 당 데이터 사이즈 및 오버헤드 사이즈 중 적어도 하나를 제거하여, 전술의 수학식 7과 같이, 상기 각 후보 전송파라미터(

)에 따른 오류확률

별로 각 후보 결합데이터사이즈를 계산할 수 있다.Thereafter, the operation method of the receiving device 100 according to the present invention, each error probability

Candidate combined data frame sizes

), Each error probability

Each candidate transmission parameter corresponding to

By removing at least one of the data size and the overhead size per symbol according to), as shown in equation (7), each of the candidate transmission parameters (

Error probability according to)

For each candidate combined data size can be calculated for each.

에 대응되는 각 후보 전송파라미터(

) 별 각 후보 결합데이터사이즈(

)를 계산할 수 있다.Thus, in the operation method of the receiving apparatus 100 according to the present invention, each error probability through the equation (7)

Each candidate transmission parameter corresponding to

Each candidate combined data size

) Can be calculated.

) 및 상기 각 후보 결합데이터사이즈(

) 중, 최대 전송효율을 갖는 특정 전송파라미터 및 특정 결합데이터사이즈 중 적어도 어느 하나를 선택한다(S170).The operation method of the reception apparatus 100 according to the present invention includes the above candidate transmission parameters (

) And each candidate combined data size (

), At least one of a specific transmission parameter having a maximum transmission efficiency and a specific combined data size is selected (S170).

)에 대응하여 계산된 상기 각 후보 결합데이터사이즈(

), 공간 스트림 수(Ns), 상기 데이터프레임을 전송하는데 소요되는 전송시간 중 적어도 어느 하나를 기초로 상기 전송효율을 계산하여, 계산된 전송효율 중 최대 전송효율 계산 시 이용된 후보 전송파라미터 및 후보 결합데이터사이즈를 상기 특정 전송파라미터 및 상기 특정 데이터유닛사이즈로서 선택할 수 있다.That is, the operation method of the receiving apparatus 100 according to the present invention, the candidate transmission parameters (

The candidate combined data size calculated according to

The candidate transmission parameters and candidates used for calculating the maximum transmission efficiency among the calculated transmission efficiencies by calculating the transmission efficiency based on at least one of the number of spatial streams (Ns) and the transmission time for transmitting the data frame. The combined data size can be selected as the specific transmission parameter and the specific data unit size.

For example, in the method of operating the reception apparatus 100 according to the present invention, the MAC throughput may be calculated through Equation 8 described above.

The DCF operation time may consider all of the transmission success, transmission failure, and backoff time in the DCF operation, and may only consider the transmission success time for convenience. Accordingly, parameter selection criteria for maximizing the MAC throughput when only the transmission success time is considered in Equation 9 from Equation 8 are presented.

)과 전송파라미터 즉 AMCS 파라미터 (

)를 선택할 수 있다.Thus, the operation method of the receiving apparatus 100 according to the present invention, the optimal combined data size (maximum given MAC throughput used in calculating the transmission efficiency through the above equation (9) (

) And transmission parameters, i.e. AMCS parameters (

) Can be selected.

)과 전송파라미터 (

)를 전송장치(200)로 제공한다(S180).In addition, the operation method of the receiving apparatus 100 according to the present invention is selected optimal combined data size (

) And transmission parameters (

) Is provided to the transmitter 200 (S180).

Hereinafter, a method of operating the transmitter according to the present invention will be described in detail with reference to FIG. 6.

In the operation method of the transmitter 200 according to the present invention, at least one of a specific transmission parameter selected by the receiver 100 and a specific combined data size is acquired (S200).

That is, in the operating method of the transmission apparatus 200 according to the present invention, in order to obtain an optimal combined data size and transmission parameter that can guarantee the probability of packet loss in a wireless LAN environment, request optimal information from the reception apparatus 100. In response thereto, the receiver 100 may receive / acquire optimal information including the specific transmission parameter and the specific combined data size selected as described above.

In the operation method of the transmission device 200 according to the present invention, the combined data is generated by combining two or more data units based on a specific combined data size (S210).

)를 기반으로 결합한 데이터유닛(MSDU) 갯수를 결정하여 결합할 수 있다.That is, in the method of operating the transmitter 200 according to the present invention, two or more data units (MSDUs) transmitted from an upper layer (data connection layer) are aggregated through confirmation of a destination address DA and a traffic type. In order to classify and classify the data units for the plurality of data units as shown in FIG. 7 as each subframe, the optimal information obtained from the receiving apparatus 100, that is, the combined data size (

Based on the number of combined data units (MSDU) can be determined by combining.

)를 기반으로, 전술의 수학식 10에 따라 집합화/결합된 결합데이터(A-MSDU)를 얻을 수 있다.For example, the operation method of the transmission device 200 according to the present invention, the optimal information obtained from the reception device 100, that is, the combined data size (

), The combined data (A-MSDU) aggregated / combined can be obtained according to the above equation (10).

In addition, in the operating method of the transmission apparatus 200 according to the present invention, as shown in FIG. 1, the combined data frame by adding a Service, MAC header, FCS, and Tail to the combined / combined combined data (A-MSDU) Create

The operation method of the transmitter 200 according to the present invention generates a data frame including the combined data (S220).

That is, the operation method of the transmitter 200 according to the present invention generates a data frame by adding a PHY header to the combined data frame more precisely than the combined data generated in step S210 as shown in FIG. 1.

)에 포함된 부호율 및 변조도 중 적어도 어느 하나를 기초로 채널 부호화 및 변조 중 적어도 어느 하나를 수행하고, 또한 수신장치(100)로부터 획득한 최적 정보 즉 전송파라미터(

)에 포함된 공간 스트림 수를 기초로 안테나를 선택하고(S230), 선택된 안테나를 통해 상기 데이터프레임을 수신장치(100)로 전송한다(S240).In addition, in the operating method of the transmitter 200 according to the present invention, corresponding to the generated data frame, the optimum information obtained from the receiver 100, that is, the transmission parameter (

) Performs at least one of channel encoding and modulation based on at least one of a code rate and a modulation degree included in the C), and also obtains optimal information, that is, a transmission parameter

An antenna is selected based on the number of spatial streams included in S) (S230), and the data frame is transmitted to the receiving apparatus 100 through the selected antenna (S240).

는, 변조도(M), 부호율(Rc), 그리고 공간적 스트림 수(Ns)를 포함한다.In other words, transmission parameters, i.e. AMCS parameters

Includes a modulation degree (M), a code rate (Rc), and a spatial stream number (Ns).

)에 포함된 변조도(M), 부호율(Rc)을 이용하여 데이터프레임에 대응하여 채널 부호화 및 변조를 수행한다.Accordingly, in the method of operating the transmitter 200 according to the present invention, in performing channel encoding and modulation on a data frame for stable data transmission and speed improvement, optimal information acquired from the receiver 100, that is, a transmission parameter (

Channel coding and modulation are performed in correspondence to the data frame using the modulation degree M and the code rate Rc included in the "

)에 포함된 공간 스트림 수를 기초로 전송 시 이용하는 안테나를 선택하고, 선택된 안테나를 통해 상기 데이터프레임을 수신장치(100)로 전송하게 된다.In addition, in the method of operating the transmitter 200 according to the present invention, in transmitting a data frame to the receiver 100, the optimal information obtained from the receiver 100, that is, a transmission parameter (

An antenna to be used for transmission is selected based on the number of spatial streams included in the), and the data frame is transmitted to the receiving apparatus 100 through the selected antenna.

As described above, a method of operating a receiver and a method of operating a transmitter for supporting a data unit combined transmission service for jointly transmitting a data unit through a wireless LAN system are based on a signal-to-noise ratio (SINR) for a wireless channel. The error probability FEP corresponding to each candidate transmission parameter is calculated to determine the link status, and the candidate combined data size that guarantees the specific packet damage probability corresponding to the specific application in use is calculated and transmitted among the candidate transmission parameters and the candidate combined data size. Determining the optimal transmission parameter and combined data size that leads to maximum efficiency, and generating combined data (A-MSDU) combining data units at the transmitter side based on the determined optimal combined data size. Data frame can be transmitted according to the optimal transmission parameters .

Accordingly, a method of operating a receiver and a method of operating a transmitter for supporting a data unit combined transmission service for jointly transmitting a data unit through a wireless LAN system may include transmission of a PHY layer so as to guarantee QoS corresponding to an application in use. By optimally determining / changing parameters and optimizing the length of the A-MSDU of the MAC layer, it is possible to maximize the data transmission efficiency and ensure the packet loss probability of the application in use, thereby ensuring the quality of data communication.

Meanwhile, the steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of both. A software module may reside in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. Alternatively, the storage medium may be integrated into the processor. The processor and the storage medium may be included within an ASIC. The ASIC may be included in the user terminal device. In the alternative, the processor and the storage medium may be included as separate components within the user terminal device.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

In the data unit combined transmission scheme, the transmission parameters of the PHY layer are optimally determined and changed to optimize QoS for the application in use, and the length of the A-MSDU of the MAC layer is optimized, thereby maximizing data transmission efficiency. When applying the receiver and the transmitter of the data unit combined transmission system that guarantees the quality of data communication by guaranteeing the probability of packet damage of the application being used, the network throughput and operational efficiency, system quality and user satisfaction are very large. Advancements can be made and the possibilities for the commercial or commercial application of the applied radio relay and terminal equipment and system solutions are sufficient and can be carried out in a realistic manner.

100: receiver
200: transmission device

Claims (15)

In the transmission system,
A signal-to-noise ratio calculator for calculating signal-to-noise ratio information of the wireless channel using information of the wireless channel;
An error probability calculator for calculating an error probability corresponding to each candidate transmission parameter based on the signal-to-noise ratio information;
A size calculator for calculating candidate combined data sizes satisfying a specific packet damage probability corresponding to a specific application for each error probability according to each candidate transmission parameter; And
And an optimal information selection unit for selecting at least one of a specific transmission parameter having a maximum transmission efficiency and a specific combined data size among each candidate transmission parameter and each candidate combined data size. Receiver. The method of claim 1,
The size calculation unit,
A combined data frame size calculator for calculating a candidate combined data frame size satisfying the specific packet damage probability for each error probability according to each candidate transmission parameter;
From each candidate combined data frame size calculated for each error probability, at least one of a data size per symbol and an overhead size according to each candidate transmission parameter corresponding to each error probability is removed, thereby allowing each candidate transmission parameter. And a combined data size calculator for calculating each candidate combined data size for each probability of error. 3. The method of claim 2,
The optimum information selection unit,
Maximum transmission efficiency is calculated by calculating transmission efficiency based on at least one of the candidate combined data size, the number of spatial streams, and the transmission time required to transmit the data frame, calculated for each candidate transmission parameter. And at least one of a candidate transmission parameter and a candidate combined data size corresponding to the efficiency. The method of claim 1,
And a data storage unit for storing a predetermined packet damage probability corresponding to at least one application type. The method according to any one of claims 1 to 4,
And a data providing unit for providing at least one of the selected specific transmission parameter and a specific combined data size to a transmission device. In the transmission system,
An information acquisition unit for acquiring at least one of a specific transmission parameter and a specific combined data size selected by the receiver; And
And a combined data generation unit for generating combined data by combining two or more data units based on the specific combined data size. The method according to claim 6,
A data frame generation unit generating a data frame including the combined data; And
And a data transmitter for performing at least one of channel encoding and modulation based on at least one of a code rate and a modulation degree included in the specific transmission parameter in response to the data frame. Transmission system of the system. The method of claim 7, wherein
The data transmission unit,
And transmitting the data frame to the receiving apparatus through an antenna selected based on the number of spatial streams included in the specific transmission parameter. In the transmission service,
A signal-to-noise ratio calculation step of calculating signal-to-noise ratio information of the wireless channel using information of the wireless channel;
An error probability calculation step of calculating an error probability corresponding to each candidate transmission parameter based on the signal-to-noise ratio information;
A size calculation step of calculating a candidate combined data size satisfying a specific packet damage probability corresponding to a specific application for each error probability according to each candidate transmission parameter; And
And an optimal information selection step of selecting at least one of a specific transmission parameter having a maximum transmission efficiency and a specific combined data size among each candidate transmission parameter and each candidate combined data size. Method of operation of the receiving device. The method of claim 9,
The size calculation step,
A combined data frame size calculation step of calculating a candidate combined data frame size that satisfies the specific packet damage probability for each error probability according to each candidate transmission parameter;
From each candidate combined data frame size calculated for each error probability, at least one of a data size per symbol and an overhead size according to each candidate transmission parameter corresponding to each error probability is removed, thereby allowing each candidate transmission parameter. And a combined data size calculation step of calculating each candidate combined data size for each probability of error according to the error probability. 11. The method of claim 10,
The optimal information selection step,
Maximum transmission efficiency is calculated by calculating transmission efficiency based on at least one of the candidate combined data size, the number of spatial streams, and the transmission time required to transmit the data frame, calculated for each candidate transmission parameter. And selecting at least one of a candidate transmission parameter and a candidate combined data size corresponding to the efficiency. 12. The method according to any one of claims 9 to 11,
And providing at least one of the selected specific transmission parameter and a specific combined data size to a transmission device. In the transmission service,
An information acquiring step of acquiring at least one of a specific transmission parameter and a specific combined data size selected by the receiver; And
And a combined data step of generating combined data by combining two or more data units based on the specific combined data size. The method of claim 13,
A data frame generation step of generating a data frame including the combined data; And
And a data transmission step corresponding to the data frame, performing at least one of channel encoding and modulation based on at least one of a code rate and a modulation degree included in the specific transmission parameter. Method of operation of a transmitter of a combined transport service. 15. The method of claim 14,
The data transmission step,
And transmitting the data frame to the receiving apparatus through an antenna selected based on the number of spatial streams included in the specific transmission parameter.

Images