KR20130096607A - Base station and method for providing a threshold value of adaptive modulation and coding to device, and the device - Google Patents

Abstract

A base station apparatus and method for transmitting an AMC threshold to a plurality of terminals, and a terminal are provided. More specifically, a stream receiving a stream of each of a plurality of layers encoded from broadcast video data by scalable video coding (SVC) is received, and from each stream of the plurality of layers based on a spring code encoding. Generate a spring code packet of each of the plurality of layers, determine an adaptive modulation and coding (AMC) threshold corresponding to each of the plurality of layers based on the generated spring code packet, and determine the determined adaptive modulation coding threshold. A base station apparatus and method for transmitting an AMC threshold for transmitting a plurality of terminals to a plurality of terminals, and a terminal are provided.

Description

A base station apparatus and method for providing an adaptive modulation encoding threshold to a terminal, and a terminal TECHNICAL FIELD

The present invention relates to a base station control apparatus and method for providing a threshold value to a terminal and a terminal, and more particularly, to a base station apparatus and method for calculating and providing an adaptive modulation coding threshold value of each of a plurality of layers, and a terminal.

Recently, with the high speed of the wireless network (4G) and the Internet, multimedia content services based on video in a broadcasting convergence environment such as video streaming, mobile broadcasting, and IPTV are becoming common. Along with the generalization of video services, N-Screen services that can use streaming services seamlessly in various devices having different resolutions such as smart phones, tablet PCs, PCs, and TVs are required.

Scalable Video Coding (SVC) is a video coding scheme designed to be able to adapt in real time according to a resolution that can be supported by various terminals. Video coding required to satisfy the requirements of the N-Screen service is possible. That's the way.

On the other hand, quality degradation caused by packet loss on wired and wireless networks is one of the main obstacles to providing IPTV services over a wide range of areas. However, by introducing a solution to cope with packet loss, it is possible to improve the IPTV service quality based on the IP network. In particular, Fountain Codes can be a means to overcome packet loss on the network.

The multicast transmission method can provide a broadcast service in a wireless system with limited bandwidth, and can increase the efficiency of the service by receiving content by sharing a radio resource with a plurality of mobile terminals. Since a plurality of terminals are provided with a service using the same radio resources, the resources required compared to the unicast transmission method, a method of allocating radio resources to each terminal to provide a service even if the number of terminals accessing the broadcast service increases. The amount of can be kept constant. However, even in multicast transmission, there is a limitation that sufficient quality service may not be provided to a terminal user far from a base station or particularly at a cell boundary. The reason is that the signal-to-noise ratio (SNR) decreases as the distance between the base station and the terminal increases, and as a result, the low data rate degrades the quality of service.

In addition, the transmission rate of the multicast is greatly affected by the channel conditions. In the multicast system, since the service is provided based on the lowest SINR measured between the base station and each terminal, the transmission rate is limited. Therefore, multicast transmission is a useful technique for transmitting data to many users at the same time by using system resources efficiently, but it is difficult to guarantee stable service quality with sufficient transmission rate for all users.

The present invention provides a plurality of broadcasts of a plurality of scalable layered images in a plurality of layers through scalable video coding (SVC) for video images of various resolutions according to the terminal screen size of viewers in a wireless communication system. When providing multicast broadcasting service allocated to each channel, AMC and spring code are used for each layer and AMC threshold is designed to maximize bandwidth efficiency in meeting the frame error rate.

In addition, as a terminal provided with an AMC threshold, in order to prevent unnecessary waste of resources, the terminal receives a stream of layers having a threshold lower than its SNR value, and requests transmission stop when all necessary packets are received.

Also, in order to prevent unnecessary waste of resources, the terminal receives image quality information of all layers and decodes only the stream of the layer that the terminal can support.

As a technical means for achieving the above technical problem, an embodiment of the present invention provides a frame input unit for receiving a frame of each of a plurality of layers encoded from broadcast video data by scalable video coding (SVC) AMC threshold determining unit for determining an adaptive modulation and coding (AMC) threshold corresponding to each frame of the plurality of layers, AMC threshold transmission for transmitting the determined adaptive modulation coding threshold to the terminal It provides a base station apparatus comprising a unit.

In addition, according to another embodiment of the present invention, the terminal further comprises a target frame error probability input unit for receiving a maximum value of the frame error probability indicating the probability of not successfully receiving the frame from the base station apparatus, the AMC The threshold determination unit may provide the base station apparatus to determine the adaptive modulation encoding threshold based on the input maximum value.

In addition, another embodiment of the present invention is a step of receiving a frame of each of a plurality of layers, encoded from the broadcast video data by scalable video coding (SVC), corresponding to each frame of the plurality of layers The present invention provides a method of transmitting an adaptive modulation encoding threshold, comprising determining an adaptive modulation coding (AMC) threshold, and transmitting the determined adaptive modulation encoding threshold to the terminal.

In addition, another embodiment of the present invention is an AMC threshold input unit for receiving an adaptive modulation encoding threshold value corresponding to each frame of a plurality of layers determined from the base station apparatus, encoded packets and encoding of a plurality of layers from the base station apparatus Provided is a terminal including a packet input unit for receiving a predetermined spring code packet, a decoding unit for decoding the received encoded packet and an encoded spring code packet, and a display unit for displaying a frame including the decoded packet.

In the present invention, by independently transmitting a plurality of SVC layers, by designing the appropriate AMC threshold for each layer, while meeting the target frame error probability, it is possible to maximize the bandwidth efficiency. In addition, as a terminal receiving an AMC threshold, the terminal receives streams of layers having an AMC threshold lower than its SNR value, requests transmission stop when all necessary packets are received, and receives the terminal from image quality information of the received streams. Only packets of this supportable layer can be decoded to avoid unnecessary waste of resources.

1 is a block diagram of a multimedia providing system according to an embodiment of the present invention.
2 is a configuration diagram of the base station apparatus 100 shown in FIG.
3 is a block diagram of a base station apparatus 100 according to another embodiment of the present invention.
4 is a diagram illustrating a frame transmission process of an n th layer according to an embodiment of the present invention.
FIG. 5 illustrates an example of a process of determining an adaptive modulation encoding threshold for each layer in the AMC threshold determination unit 120 according to an embodiment of the present invention.
6 is a flowchart illustrating an AMC threshold transmission method according to an embodiment of the present invention.
7 is a configuration diagram of the terminal 200 shown in FIG. 1.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is referred to as being "connected" to another part, it includes not only "directly connected" but also "electrically connected" with another part in between . Also, when an element is referred to as "comprising ", it means that it can include other elements as well, without departing from the other elements unless specifically stated otherwise.

1 is a block diagram of a multimedia providing system according to an embodiment of the present invention. Referring to FIG. 1, a multimedia providing system includes a multimedia server 300, a base station apparatus 100, and a plurality of terminals 201 to 203. However, since the multimedia providing system of FIG. 1 is only an embodiment of the present invention, the present invention is not limitedly interpreted through FIG. 1.

Each component of FIG. 1 constituting the multimedia providing system is generally connected through a network. The network refers to a connection structure capable of exchanging information between nodes such as terminals and servers. An example of such a network is the Internet, a LAN (Local Area Network), a Wireless LAN Local Area Network (WAN), Wide Area Network (WAN), Personal Area Network (PAN), and the like.

The multimedia providing server 300 provides a multimedia frame to the base station apparatus 100. In this case, the multimedia frame refers to a plurality of layered frames through scalable video coding (SVC).

According to an embodiment of the present invention, the plurality of layers layered by scalable video coding includes a base layer and at least one enhancement layer. In general, the base layer includes information necessary for minimum image reproduction, and the other enhancement layers include additional information for improving image quality.

In general, scalable video coding (SVC) is a video coding scheme designed to be adapted in real time according to a resolution that can be supported by various terminals, and is required to satisfy the requirements of the N-Screen service. Video encoding method.

In other words, through scalable video coding, a format suitable for a variable environment such as various resolutions and network conditions required by a terminal can be supported in real time. At this time, the video data is divided into one base layer and a plurality of enhanced layers. The receiving end can decode even if only the base layer data is received. However, the receiver can further enhance the resolution of the video by receiving enhancement layers. Data encoded through scalable video coding is transmitted to a downlink channel through multicast transmission in a cellular environment, and a user can be provided with a broadcast service using various terminals, so that users can obtain an image having a resolution suitable for their device. The service may be provided through scalable video coding.

The base station apparatus 100 determines an adaptive modulation encoding threshold corresponding to each frame of a plurality of layers provided from the multimedia server 300, and generates a spring code packet based on the packet included in the frame. The base station apparatus 100 transmits the encoded packet and the encoded spring code packet to each of the terminals 201 to 203 based on the determined adaptive modulation encoding threshold and the adaptive modulation encoding mode.

In general, when a code rate of error correction coding is expressed as (amount of existing information) / (amount of encoded data), the amount of coded data is not known in advance, so it is also called 'Rateless code'. Such a spring code has the advantage of allowing perfect reception without errors (only one-way transmission) even when there is a lack of information on successful reception at the receiving end or a large number of receiving parties. Have. Thus, well water is known to be useful when providing multicast services within a computer network.

If a large amount of data must be delivered to multiple receivers over an IP network, the unicast protocol sends feedback to the transmitter, requesting retransmission of packets that it did not receive. Resend the packets. However, in a multi-user communication environment, a large number of retransmission requests are generated at each receiving end, so the amount of feedback increases exponentially, and the load on the network is increased due to the retransmission request and the retransmitted packets.

Therefore, in order to eliminate the retransmission request that causes network overload for the multicast service and to enable the asynchronous reception of the receiver, the following communication scheme can be considered. First, the transmitting end continuously generates an infinite amount of encoded packets using the data to be transmitted. If so, each receiving end can decode the packet if it receives only enough packets to decode it. The spring code is based on this approach.

The reason why such a channel coding technique for transmission is called a spring water code is because the transmission method is similar to obtaining water from a fountain. The fountain always pumps out an almost infinite amount of water, and a cup can be placed anywhere near it to fill the desired amount of water. In the spring water code, the transmitting end is named similarly to a fraction because the transmitting end encodes and transmits a fixed amount of information almost infinitely and the receiving end gets the information regardless of which of the receiving end.

The coding technique of the spring code generates an infinitely large amount of encoding symbols with given K source symbols. Here, the source symbol and the encoding symbol may be 1 bit, but may be a vector representing a packet of several bits. It is assumed that the receiver knows all of the encoding process. It is also assumed that the receiver knows how each of the received encoded symbols is generated. Such information can be implemented in such a way that each encoding symbol includes its generation information.

The random spring code is made up of an XOR sum by randomly selecting source symbols to generate respective encoding symbols. The probability that each source symbol is selected is 1/2.

This coding scheme is similar to the random block coding scheme, and this process can be simply expressed as a generation matrix. Since the random spring code generates an infinite number of encoding symbols, the generation matrix is represented by a matrix having K rows and an infinite number of columns. Each column and the corresponding encoding symbol use a column vector randomly selected from 0 or 1 to determine the portion of the source symbol to use as the XOR sum. This probability distribution allows a total of 2K possible column vectors to be selected with the same probability. That is, it means that the probability in all cases of selecting a part of the source symbol to generate one encoding symbol is the same.

The decoding process of the random spring code assumes that all of the encoding symbols are the result of XOR sum using the source symbols of K, as in the basic assumption of the spring code described above. Accordingly, the receiver may receive the remaining encoded symbols partially erased by the channel and obtain a new generation matrix G consisting of only the column vectors of the corresponding generation matrices. Since the receiving end knows the generation matrix G 'corresponding to the received encoding symbol without being erased, the receiving end performs ML decoding using this.

The multicast transmission scheme may be used to provide a broadcast type service in a wireless system with limited bandwidth. Since a plurality of terminals are provided with a service using the same radio resources, the resources required compared to the unicast transmission method, a method of allocating radio resources to each terminal to provide a service even if the number of terminals accessing the broadcast service increases. The amount of can be kept constant. However, even in multicast transmission, there is a limitation that sufficient quality service may not be provided to a terminal user far from a base station or particularly at a cell boundary. The reason is that the signal-to-noise ratio (SNR) decreases as the distance between the base station and the terminal increases, and as a result, the low data rate degrades the quality of service. In addition, the transmission rate of the multicast is greatly affected by the channel state. In the multicast system, since the service is provided based on the lowest SINR measured between the base station and each terminal, the transmission rate is limited.

Therefore, although the multicast transmission scheme is a useful technique for transmitting data to many users at the same time by using system resources efficiently, it is difficult to guarantee stable service quality at a sufficient transmission rate for all users. To this end, as shown in Figure 1, the terminals located in the cell edge region can reduce the bandwidth efficiency, and can improve the bandwidth efficiency only for the terminals located in the cell center.

Accordingly, the base station can use various modes of adaptive modulation and coding (AMC) for multicast data transmission. Each AMC mode has a threshold for proper operation and occupies the OFDMA region for the same amount of data transmission. The amount of resource zones is different. When the OFDMA system wants to provide IPTV service through multicast, it is necessary to select an AMC mode with a low SNR threshold so that all possible terminals can be provided with the service. You may need to select AMC mode. In other words, it can be seen that there is a beneficial relationship between service coverage and resource efficiency.

According to various embodiments of the present invention, each of the plurality of terminals 21 to 23 is various types of terminals. For example, the terminal may be a TV device, a computer, or a portable terminal capable of connecting to a remote server via a network. Here, an example of the TV apparatus includes a smart TV, an IPTV set-top box, and the like. Examples of the computer include a notebook computer, a desktop computer, a laptop computer, One example of the terminal includes a Personal Communication System (PCS), a Global System for Mobile Communications (GSM), a Personal Digital Cellular (PDC), a Personal Handyphone System (PHS) Assistant, IMT (International Mobile Telecommunication) -2000, Code Division Multiple Access (CDMA) -2000, W-Code Division Multiple Access (W-CDMA), Wibro (Wireless Broadband Internet) terminals, smart phones, And the like may be included in the present invention.

Hereinafter, the operation of the base station apparatus 100 of FIG. 1 will be described in more detail.

2 is a configuration diagram of the base station apparatus 100 shown in FIG. 2, the base station apparatus 100 includes a frame input unit 110, an AMC threshold determination unit 120, an AMC threshold transmission unit 130, and a database 199. However, the base station apparatus 100 shown in FIG. 2 is just one implementation example of the present invention, and various modifications are possible based on the components shown in FIG. 2. For example, the base station apparatus 100 may further include a manager interface for receiving a certain command or information from the manager. In this case, the manager interface may be an input device such as a keyboard, a mouse, or the like, but may be a graphical user interface (GUI) represented on a video display device.

The frame input unit 110 receives frames of a plurality of layers from the multimedia server 300. In this case, the frames of the plurality of layers refer to frames of the plurality of layers encoded from broadcast video data by scalable video coding (SVC).

The AMC threshold determiner 120 determines an adaptive modulation encoding threshold for each layer of a plurality of layers of frames received from the frame input unit 110. The determined adaptive modulation encoding threshold is stored in the database 199.

The AMC threshold transmitter 130 transmits the adaptive modulation encoding threshold determined by the AMC threshold determiner 120 to the terminal 200.

Database 199 stores data. In this case, the data includes data input and output between the components of the base station apparatus 100, and data input and output between the base station apparatus 100 and components outside the base station apparatus 100. do. For example, the database 199 may store the adaptive modulation encoding threshold transmitted from the AMC threshold determiner 120 to the AMC threshold transmitter 130. An example of such a database 199 includes a hard disk drive, a read only memory (ROM), a random access memory (RAM), a flash memory, a memory card, and the like existing inside or outside the base station apparatus 100.

Hereinafter, another embodiment of the operation of the base station apparatus 100 of FIG. 1 will be described in detail.

3 is a block diagram of a base station apparatus 100 according to another embodiment of the present invention. Referring to FIG. 3, the base station apparatus 100 includes a frame input unit 110, an AMC threshold determination unit 120, an AMC threshold transmission unit 130, a target frame error probability input unit 140, and a spring code packet generation unit. 150, an adaptive modulation encoder 160, a packet transmitter 170, an image quality information transmitter 180, a transmission stop signal input unit 190, and a database 199. However, the base station apparatus 100 shown in FIG. 3 is only one implementation example of the present invention, and various modifications are possible based on the components shown in FIG. 3. For example, as described above with reference to FIG. 2, the base station apparatus 100 may further include a manager interface for receiving a certain command or information from the manager.

The frame input unit 110 receives streams of a layer from the multimedia server 300.

According to an embodiment of the present invention, the plurality of layers may include a base layer and at least one enhancement layer. At this time, the base layer is a layer capable of restoring a basic broadcast video using only data of the base layer, and the enhancement layer is a layer capable of restoring a better quality enhancement broadcast video than the base broadcast video using the base layer and the data of the enhancement layer. Can be.

The AMC threshold determiner 120 determines an adaptive modulation encoding threshold for each layer of a plurality of hierarchical frames input from the frame input unit 110. The frame error probability received from the target frame error probability input unit 140 is determined. An adaptive modulation encoding threshold corresponding to each of the plurality of layers may be determined based on the maximum value of. The frame error probability refers to a probability that the terminal does not successfully receive a frame from the base station apparatus.

According to an embodiment of the present invention, the AMC threshold determination unit 120 determines the adaptive modulation encoding threshold based on the number of K packets included in the frame received from the frame input unit 110.

According to another embodiment of the present invention, the AMC threshold determination unit 120 is a maximum value of the frame error probability received from the target frame error probability input unit 140, the packet included in the frame received from the frame input unit 110; The adaptive modulation encoding threshold value is determined based on at least one of the number and the number of the spring code packets generated based on the spring code encoding from the packets included in the frames received by the frame input unit 110.

According to another embodiment of the present invention, the AMC threshold determination unit 120 determines the adaptive modulation encoding threshold based on the target packet error rate of any one of the packet included in the frame and the spring code packet. Here, the target packet error rate refers to an allowable target value of a packet loss rate at which the terminal 200 does not receive the packet when the packet transmitter 170 transmits the packet to the terminal 200. The target packet error rate is determined based on at least one of the maximum value of the frame error probability, the number of packets included in the frame, and the number of spring code packets.

The AMC threshold transmitter 130 transmits the adaptive modulation encoding threshold determined by the AMC threshold determiner 120 to the plurality of terminals 200.

The target frame error probability input unit 140 receives a maximum value of the frame error probability indicating the probability that the terminal 200 does not successfully receive a frame from the base station apparatus 100.

The spring code packet generation unit 150 generates the spring code packet based on the spring code encoding of the packets included in the frames from the frames of the plurality of layers received by the frame input unit 110.

According to an embodiment of the present invention, the spring code packet generation unit 150 is a spring code based on the spring code encoding from at least one packet included in any one frame among a plurality of layers received by the frame input unit 110. You can create a packet.

The adaptive modulation encoding unit 160 may encode the packet received by the spring code packet generation unit 150 and the spring code packet generated based on the sample based on the adaptive modulation encoding mode.

According to another embodiment of the present invention, the adaptive modulation encoding unit 160 generates an error correction encoding packet based on the error input encoding packet and the generated spring code packet inputted from the spring code packet generation unit 120, The generated error correction encoded packet may be generated based on the adaptive modulated encoding.

The packet transmitter 170 transmits the packet encoded by the adaptive modulation encoder 160 and the encoded spring code packet to the terminal 200.

According to another embodiment of the present invention, the packet transmitter 170 may provide a packet received from the frame input unit 110 or a packet and a spring code packet received from the frame input unit 110 to the terminal 200. In addition, the error correction coded packet may be transmitted to the terminal 200.

According to another exemplary embodiment of the present invention, the packet transmitter 170 receives a transmission stop signal of the encoded spring code packet of any one of a plurality of layers from the terminal 200 by the transmission stop signal input unit 190. At this time, the transmission of the encoded spring code packet transmitted to the plurality of terminals 200 may be stopped. In this case, the spring code packet may be an encoded packet or may include both an encoded packet and an encoded spring code packet.

The image quality information transmitter 180 transmits the image quality information supported by the frames of the plurality of layers received by the frame input unit 110 to the terminal 200. In this case, the image quality information may be received from the multimedia server 300 or analyzed by the base station apparatus 100.

The transmission stop signal input unit 190 receives a transmission stop signal of an encoded spring code packet of any one of a plurality of layers from the terminal 200.

Database 199 stores data. In this case, the data includes data input and output between the components of the base station apparatus 100, and data input and output between the base station apparatus 100 and components outside the base station apparatus 100. do. For example, the database 199 may store an adaptive modulation encoding threshold, the number of packets included in a frame, the number of spring code packets, a target frame error probability, a target packet error rate, and image quality information.

The terminal 200 is based on at least one layer of a plurality of layers transmitted to the terminal 200 based on the adaptive modulation coding threshold of each of the plurality of layers transmitted from the AMC threshold value transmitter 130 to the terminal 200. Receive packets selectively.

According to an embodiment of the present invention, the terminal 200 determines a signal-to-noise ratio (SNR) of the terminal 200, and in the determined signal and noise ratio and the AMC threshold transmitter 130. By comparing the adaptive modulation encoding thresholds of the plurality of layers transmitted to the terminal 200, packets of at least one layer among the plurality of layers transmitted to the terminal 200 may be selectively received.

The matters not described above with respect to the stream input unit 110, the AMC threshold determination unit 120, the AMC threshold transmission unit 130, and the database 199 are the same as those described above with reference to FIG. 2. Or, it will be easily inferred by those skilled in the art from the contents described, so description is omitted.

4 is a diagram illustrating a frame transmission process of an n th layer according to an embodiment of the present invention. The frames of each of the plurality of layers encoded by all scalable video coding undergo the same process. Referring to FIG. 4, a frame of an nth layer among a plurality of layers encoded by scalable video coding input from the frame input unit 110 is composed of K packets, and the spring code packet generation unit 150 includes K packets. Generate L spring code packets based on the packet.

The adaptive modulation encoding unit 160 generates K encoded packets and L encoded spring code packets from K packets and L spring code packets based on the adaptive modulation encoding.

The encoded K + L packets are transmitted to the packet input unit 220 of the terminal 200 through the packet transmitter 170. In this case, packet loss may occur during transmission of the encoded K + L packets over a wireless channel.

The packet input unit 220 of the terminal 200 transmits the encoded packet inputted after successful reception without packet loss to the decoding unit 230, and the decoding unit 230 is a packet of a frame of the n-th layer required for decoding. When K or more encoded packets are received, the frames are decoded by decoding the received packets.

Hereinafter, Table 1 shows the variables and variables used in the process of determining the adaptive modulation coding threshold for each layer by the AMC threshold determining unit 120 according to an embodiment of the present invention. Include each definition. FIG. 5 illustrates an example of a process of determining an adaptive modulation encoding threshold for each layer in the AMC threshold determination unit 120 according to an embodiment of the present invention.

[Table 1]

Referring to Table 1, an embodiment of the present invention is as follows.

Packet Error Rate Based on Adaptive Modulation Coding Threshold of Second Layer

Since the exact formula does not exist, it can be obtained when applying the Convolutional Turbo Code through simulation by Monte Carlo experiment. The secured packet error rate may be expressed as Equation 1 in the following simple form to facilitate analysis.

[Equation 1]

here

Is an index representing the hierarchy

),

,

And

Are the first to third parameters calculated through curve fitting to the results obtained through the simulation.

Also,

Quot;

Packet Error Rate Based on Adaptive Modulation Coding Threshold of Second Layer

Is the target packet error rate

Is the maximum value,

Adaptive Modulation Coding Threshold of the Second Layer

May be expressed as Equation 2 below based on Equation 1.

&Quot; (2) "

therefore,

Adaptive Modulation Coding Threshold of the Second Layer

Is the first to third parameters and a given target packet error rate

Can be obtained on the basis of At this time,

Packet error rate when

Is 1 (always failed to send), so we'll leave it out.

According to another embodiment of the present invention, a target packet error rate

The

The number of packets of packets in the frame of the first layer

,

Packet count of the spring code packet of the first layer

And target frame error probability received

It can be determined based on, as will be described below.

The packet transmitter 170 to the terminal 200

The transmission opportunity of one encoded packet

There is an opportunity to transmit one coded spring code packet.

Through one transmission opportunity

When the second transmission, the terminal 200

Probability of successfully receiving two packets is given by Equation 3.

&Quot; (3) "

Therefore, the terminal 200

Even after

Probability of not receiving any one of the? Encoded packets is equal to Equation 4, and the probability is a target frame error probability.

Should be less than or equal to, it can be expressed as Equation 5.

&Quot; (4) "

&Quot; (5) "

Therefore, target packet error rate

Can be obtained using equations (3) and (5).

Referring to FIG. 5, the AMC threshold determination unit 120

The number of packets of packets in the frame of the first layer

,

Packet count of the spring code packet of the first layer

And target frame error probability

Target packet error rate based on

.

Also, the AMC threshold determination unit 120 determines the determined target packet error rate.

And predetermined first to third parameters.

,

,

Based on

The adaptive modulation coding threshold of the second layer is determined.

At this time, for each layer

Value and

Value can be different,

Value and the first layer

The adaptive modulation coding threshold determined based on the value

, Second layer

Value and the second layer

The adaptive modulation coding threshold determined based on the value

, Like the Nth layer

Value and the Nth layer

The adaptive modulation coding threshold determined based on the value

.

6 is an operation flowchart illustrating a method of transmitting an adaptive modulation encoding threshold according to an embodiment of the present invention. The method of transmitting an adaptive modulation encoding threshold according to the embodiment shown in FIG. 6 includes steps processed in time series by the base station apparatus 100 according to the embodiment shown in FIG. 2. Therefore, although omitted below, the above description of the base station apparatus 100 of FIG. 2 is also applicable to the method of transmitting an adaptive modulation encoding threshold according to the embodiment shown in FIG. 6.

In operation S61, the frame input unit 110 receives a frame of a plurality of layers encoded from broadcast video data by scalable video coding (SVC). In operation S62, the AMC threshold determination unit 120 determines an adaptive modulation encoding threshold corresponding to each of the plurality of layers. In step S63, the AMC threshold transmitter 130 transmits the determined adaptive modulation encoding threshold to the terminal.

The adaptive modulation encoding threshold transmission method according to the embodiment described with reference to FIG. 6 may also be implemented in the form of a recording medium including instructions executable by a computer, such as a program module executed by a computer. Computer readable media can be any available media that can be accessed by a computer and includes both volatile and nonvolatile media, removable and non-removable media. In addition, the computer-readable medium may include both computer storage media and communication media. Computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Communication media typically includes any information delivery media, including computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave, or other transport mechanism.

7 is a configuration diagram of a terminal 200 according to an embodiment of the present invention. 7, the terminal 200 transmits an AMC threshold value input unit 210, a packet input unit 220, a decoder 230, a display unit 240, an image quality information input unit 250, and a transmission stop signal transmitter. 260 and database 299. However, the terminal 200 shown in FIG. 7 is only one implementation example of the present invention, and various modifications are possible based on the components shown in FIG. 7. For example, the terminal 200 may further include a manager interface for receiving a certain command or information from the manager.

The AMC threshold input unit 210 receives an adaptive modulation encoding threshold corresponding to each of the plurality of layers determined by the base station apparatus 100.

The packet input unit 220 receives an encoded packet and an encoded spring code packet from the base station apparatus 100.

According to an embodiment of the present invention, the packet input unit 220 is configured between an adaptive modulation encoding threshold of each of the plurality of layers received from the AMC threshold input unit 210 and its signal and noise ratio (SNR) determined by the terminal 200. Depending on the comparison result, packets of at least one layer may be selectively received. For example, the packet input unit 220 may receive a packet of at least one layer having an adaptive modulation encoding threshold lower than the SNR value of the terminal 200.

The decoder 230 decodes streams of a plurality of layers based on the encoded packet and the encoded spring code packet received from the packet input unit 220.

According to an embodiment of the present invention, the decoding unit 230 receives the packet received based on at least one of the adaptive modulation encoding mode, the error correction encoding, and the spring code encoding according to the packet type received from the packet input unit 220. Can be decrypted

According to another embodiment of the present invention, the decoding unit 230 is a terminal of the plurality of layers received from the packet input unit 220 based on the image quality information supported by each of the plurality of layers input from the image quality information input unit 250. The encoded packet and the encoded spring code packet of at least one or more layers having the supported image quality may be decoded.

The display unit 240 displays the decoding result in the decoding unit 230.

The image quality information input unit 250 receives the image information of the frames of each of the plurality of layers that the base station apparatus 100 receives from the multimedia server 300 from the image quality information transmitter 160.

The transmission stop signal transmitter 260 transmits the number of packets required by the decoder 230 to decode any one of the plurality of layers from the packet input unit 220 to the base station apparatus 100. Send a stop signal.

Database 299 stores data. At this time, the data includes data input and output between the components of the terminal 200, and includes data input and output between the terminal 200 and the components outside the terminal 200. An example of such a database 299 includes a hard disk drive, a read only memory (ROM), a random access memory (RAM), a flash memory, a memory card, or the like existing inside or outside the terminal 200.

The description of the terminal 200 applies the description of the terminal 200 described above with reference to FIGS. 1, 2, and 3. Therefore, the matters that are not described below with respect to the terminal 200 are the same as the contents described above with reference to FIGS. 1, 2, and 3 or may be easily inferred by those skilled in the art from the contents described below.

The foregoing description of the present invention is intended for illustration, and it will be understood by those skilled in the art that the present invention may be easily modified in other specific forms without changing the technical spirit or essential features of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is shown by the following claims rather than the above description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention. do.

100: base station apparatus
110: frame input unit
120: AMC threshold determination unit
130: AMC threshold transmission unit
200: terminal
210: AMC threshold input unit
300: multimedia server

Claims (19)

A base station apparatus for transmitting an adaptive modulation encoding threshold to a terminal,
A frame input unit configured to receive a frame of each of a plurality of layers encoded from broadcast video data by scalable video coding (SVC);
An AMC threshold determining unit configured to determine an adaptive modulation and coding (AMC) threshold corresponding to each frame of the plurality of layers; And
And an AMC threshold transmitter for transmitting the determined adaptive modulation encoding threshold to the terminal. The method of claim 1,
And a target frame error probability input unit configured to receive a maximum value of a frame error probability indicating a probability that the terminal does not successfully receive the frame from the base station apparatus.
And the AMC threshold determining unit determines the adaptive modulation encoding threshold based on the input maximum value. The method of claim 1,
And the AMC threshold determination unit determines the adaptive modulation encoding threshold based on the number of packets included in the frame. 3. The method of claim 2,
The AMC threshold determination unit determines the adaptive modulation encoding threshold based on at least one of the input maximum value, the number of packets included in the frame, and the number of spring code packets.
And the spring code packet is generated from the packet based on spring code encoding. 5. The method of claim 4,
The AMC threshold determining unit determines a target packet error rate of any one of the packet and the spring code packet based on at least one of the input maximum value, the number of packets included in the frame, and the number of spring code packets. And determine the adaptive modulation encoding threshold based on the determined target packet error rate. The method of claim 1,
And a spring code packet generator for generating spring code packets from frames of each of the plurality of layers based on spring code encoding. The method according to claim 6,
The spring code packet generation unit receives at least one packet included in a frame of any one layer of the plurality of layers, and generates at least one spring code packet from the input packet based on the spring code encoding. Base station apparatus. The method according to claim 6,
An adaptive modulation encoder for encoding the packet and the spring code packet based on an adaptive modulation coding mode corresponding to each of the plurality of layers; And
And a packet transmitter for transmitting the encoded packet and the encoded spring code packet to the terminal. The method of claim 8,
And the terminal selectively receives a packet of at least one layer among a plurality of layers transmitted to the terminal based on the adaptive modulation encoding threshold of each of the plurality of transmitted layers. The method of claim 9,
The terminal determines a signal-to-noise ratio (SNR) of the terminal and is transmitted to the terminal according to a comparison result between the determined signal and noise ratio and the adaptive modulation coding threshold of each of the plurality of layers. A base station apparatus for selectively receiving packets of at least one layer among a plurality of layers. The method of claim 1,
The plurality of layers includes a base layer and at least one enhancement layer, wherein the base layer is a layer capable of restoring a basic broadcast image using only data of the base layer, and the enhancement layer is data of the base layer and the enhancement layer. The base station apparatus is a layer capable of restoring an improved broadcast image having a higher quality than the basic broadcast image. The method of claim 1,
And a video quality information transmitter for transmitting the video quality information supported by each frame of the plurality of layers to the terminal. The method of claim 8,
The apparatus further includes a transmission stop signal input unit configured to receive a transmission stop signal of an encoded spring code packet of one of the plurality of layers from the terminal.
And the packet transmitter stops the transmission of the coded spring code packet based on the received transmission stop signal. In the method for transmitting the adaptive modulation encoding threshold by the base station apparatus to the terminal,
Receiving a frame of each of a plurality of layers encoded from broadcast video data by scalable video coding (SVC); Adaptive Modulation (AMC) corresponding to each frame of the plurality of layers Coding) determining a threshold; And
And transmitting the determined adaptive modulation encoding threshold to the terminal. A terminal for receiving an adaptive modulation encoding threshold value from a base station apparatus,
An AMC threshold input unit for receiving an adaptive modulation encoding threshold value corresponding to each frame of the plurality of layers determined by the base station apparatus;
A packet input unit configured to receive encoded packets and encoded spring code packets of a plurality of layers from the base station apparatus;
A decoder which decodes the received encoded packet and the encoded spring code packet; And
And a display unit for displaying a frame including the decoded packet. The method of claim 15,
The decoding unit decodes the packet received from the packet input unit based on the spring code decoding or adaptive modulation decoding. The method of claim 15,
The packet input unit may include at least one layer based on a comparison result between an adaptive modulation encoding threshold of each of the plurality of layers received from the AMC threshold input unit and a signal-to-noise ratio (SNR) determined by the terminal. Terminal for receiving a packet selectively. The method of claim 15,
An image quality information input unit which receives image quality information supported by each frame of the plurality of layers;
The decoding unit decodes an encoded packet and an encoded spring code packet of at least one layer having an image quality supported by the terminal based on the received image quality information among a plurality of layers input from the packet input unit. . The method of claim 15,
If the number of packets of any one layer input from the packet input unit is the number of packets needed to decode the layer in the decoding unit further comprises a transmission stop signal transmission unit for transmitting the packet transmission stop signal of the layer to the base station apparatus, Terminal.

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