KR100946910B1 - Apparatus and method for transmitting/receiving a common control information in a wireless communication system - Google Patents

Abstract

The present invention relates to a wireless communication system having a plurality of subscriber stations in a base station area, wherein the common control information is transmitted to all of the plurality of subscriber stations and according to channel conditions of the subscriber stations. After generating the second information to be transmitted respectively, the first order of the modulation and coding scheme (MCS: Level of Modulation and Coding Scheme (MCS) levels that can provide the first information in the base station, and the coding method of the minimum coding rate) Transmit by applying the MCS level having a second, and the second information is applied by transmitting the MCS levels adjusted by a predetermined level than the MCS levels corresponding to the channel state of each of the subscriber station to maximize the efficiency of radio resources Let's do it.

Common Control Information, AMC Method, MCS Level, DL_MAP Message, UL_MAP Message

Description

Apparatus and method for transmitting and receiving common control information in a wireless communication system {APPARATUS AND METHOD FOR TRANSMITTING / RECEIVING A COMMON CONTROL INFORMATION IN A WIRELESS COMMUNICATION SYSTEM}

1 is a view schematically showing the structure of a general IEEE 802.16a communication system

2 is a diagram schematically showing the application of the AMC scheme of a general IEEE 802.16a communication system

3 is a diagram schematically showing the application of the AMC scheme of the IEEE 802.16a communication system according to a first embodiment of the present invention

4 is a diagram schematically illustrating a transmitter structure of an IEEE 802.16a communication system for performing functions in the first and second embodiments of the present invention.

5 is a diagram schematically showing a receiver structure of an IEEE 802.16a communication system for performing functions in the first and second embodiments of the present invention.

6 is a flowchart illustrating a process of transmitting common control information in the IEEE 802.16a communication system according to the first and second embodiments of the present invention.

7 is a flowchart illustrating a process of receiving common control information in the IEEE 802.16a communication system according to the first and second embodiments of the present invention.

8 illustrates a frame structure of an IEEE 802.16a communication system according to a first embodiment of the present invention.

9 is a diagram schematically showing the application of the AMC scheme of the IEEE 802.16a communication system according to a second embodiment of the present invention

The present invention relates to a wireless communication system, and more particularly, to an apparatus and method for transmitting and receiving common control information commonly applied to subscriber stations.

In the 4th generation (4G), the next generation communication system, a variety of quality of service (QoS: hereinafter referred to as 'QoS') having a transmission rate of about 100 Mbps is used. Active research is being conducted to provide services to users. Currently, 3G (3G) communication systems generally support a transmission rate of about 384 Kbps in an outdoor channel environment having a relatively poor channel environment, and an indoor channel having a relatively good channel environment. It supports up to 2Mbps transmission speed even in the environment.

Meanwhile, a wireless local area network (LAN) communication system and a wireless metropolitan area network (MAN) communication system are generally used. It supports transmission speed of 20Mbps ~ 50Mbps. Therefore, in the current 4G communication system, a high-speed service intended to be provided by the 4G communication system by developing a new communication system in the form of ensuring mobility and QoS in a wireless LAN communication system and a wireless MAN communication system that guarantee a relatively high transmission speed. There is a lot of research going on to support this.

The wireless MAN system is a broadband wireless access (BWA) communication system, which has a wider service area and supports higher transmission speed than the wireless LAN system. Orthogonal Frequency Division Multiplexing (OFDM) scheme and Orthogonal Frequency Division Multiple Access (OFDM) for supporting a broadband transmission network in a physical channel of the wireless MAN system (OFDMA: Orthogonal Frequency Division Multiplexing Access, hereinafter referred to as 'OFDMA') is a system applying the IEEE (Institute of Electrical and Electronics Engineers) 802.16a communication system. The IEEE 802.16a communication system is a broadband wireless access communication system using an OFDM / OFDMA scheme, and the structure of the IEEE 802.16a communication system will be described with reference to FIG. 1.

1 is a diagram schematically illustrating a structure of a general IEEE 802.16a communication system.                         

Referring to FIG. 1, the IEEE 802.16a communication system has a single cell structure, and a base station (BS) 100 and a plurality of subscriber stations (SSs) managed by the base station 100. Subscriber Stations, that is, a first subscriber terminal 110, a second subscriber terminal 120, a third subscriber terminal 130, a fourth subscriber terminal 140, and a fifth subscriber terminal 150. do. Signal transmission and reception between the base station 100 and the subscriber stations (110, 120, 130, 140, 150) is performed using the OFDM / OFDMA method.

As shown in FIG. 1, the subscriber stations 110, 120, 130, 140, and 150 have different distances from the base station 100, and are generally spaced apart from the base station 100. Accordingly, the propagation environment, that is, the channel state of the subscriber stations 110, 120, 130, 140, and 150 is different. That is, the channel state of the first subscriber station 110 that is closest to the base station 100 is the best, and the channel state of the fifth subscriber station 150 that is farthest from the base station 100 is the worst. Do.

In FIG. 1, the channel state is divided into five states, namely, 'best' state, 'good' state, 'normal' state, 'poor' state, and 'poorest' state. The criterion for dividing the five channel states is based on a threshold for dividing the channel states provided by the IEEE 802.16a communication system, and the operation for dividing the channel states according to the threshold values is not directly related. The description will be omitted. In addition, the channel state between the base station 100 and the subscriber stations (110, 120, 130, 140, 150) is not only the distance that the environment is spaced apart, but also the base station 100 and the subscriber stations (110, Although it is also affected by radio interference due to obstacles or other signals existing between 120, 130, 140, and 150, in FIG. 1, only a distance spaced apart from the base station 100 is considered.

Meanwhile, in the current wireless communication system, that is, the IEEE 802.16a communication system, a burst characteristic of the packet data is used in allocating a radio resource for packet data transmission. Here, an IEEE 802.16a communication system will be described as an example of the wireless communication system. In general, when transmitting circuit data in the IEEE 802.16a communication system, a dedicated channel is allocated to an SS (subscriber station) to transmit the circuit data, and the allocated channel is allocated. The circuit data targeting the arbitrary subscriber station is transmitted through a dedicated channel. That is, when transmitting circuit data in the IEEE 802.16a communication system, radio resources are allocated exclusively to subscriber stations and the circuit data are transmitted through the dedicated radio resources.

However, in transmitting the packet data, the packet data is transmitted by allocating a shared resource, that is, a shared channel, in consideration of the efficiency of radio resources rather than the dedicated resource allocation. Thus, the base station performs a scheduling operation to dynamically allocate downlink and uplink resources for each of the subscriber stations served by the base station itself, and the base station performs the scheduling operations. Information on downlink and uplink resources allocated for each frame is provided in the form of common control information (CCI) every frame.

In addition, in the IEEE 802.16a communication system, a modulation and coding scheme (MCS: Modulation and Coding Scheme (MCS)) suitable for a radio wave environment, that is, a channel environment, of a subscriber station to receive a transmission signal is transmitted to an arbitrary subscriber station. Modulating and coding). Here, the MCS will be described.

As described above, the channel environment between the base station and the subscriber station is changed due to various factors, and thus a method of transmitting a signal by variously applying the MCS according to the channel state between the base station and the subscriber station. Adaptive Modulation and Coding (AMC) will be referred to as "AMC". That is, the AMC scheme refers to a signal transmission scheme that determines different channel modulation schemes and coding schemes according to channel states between a cell, that is, a base station and subscriber stations, thereby improving efficiency of the entire cell.

The AMC scheme has a plurality of modulation schemes and a plurality of coding schemes, and modulates and codes a channel signal by combining the modulation schemes and coding schemes. Typically, each combination of the modulation schemes and coding schemes is referred to as the MCS, and a plurality of MCSs can be defined from level 1 to level N according to the number of MCSs. That is, the AMC scheme is to improve the overall system efficiency of the base station by adaptively determining the level of the MCS according to the channel state between the base station and the subscriber station.

As described above, the IEEE 802.16a communication system transmits and receives a signal between a base station and a subscriber station according to a channel state of each subscriber station using the AMC scheme. However, since common control information such as system information (SI) and resource allocation information is information that all subscriber stations serving the base station must receive in common, the subscriber station in the worst channel state among the subscriber stations. The most robust MCS level must be applied for transmission.

For example, it is assumed that the MCS levels provided by the IEEE 802.16a communication system are shown in Table 1 below.

MCS level index Robust Resource use efficiency (information bits / transmission bits) 0 Very strong Lowest One Strong lowness 2 usually usually 3 weakness height 4 Very weak Highest

As shown in Table 1, there are five MCS levels provided by the IEEE 802.16a communication system, from level 0 to level 4, and MCS when the channel condition is good as the index of the MCS level increases. On the contrary, as the index of the MCS level decreases, the channel condition is poor. That is, when the MCS level is level 0, the lowest order modulation method and the coding method having the minimum coding rate are applied, so resource efficiency is minimal, and conversely, when the MCS level is level 4 Resource efficiency is maximized because the highest order modulation scheme and coding scheme with the highest coding rate are applied.

In addition, MCS parameters according to each of the MCS levels are included in a Downlink Channel Descript (DCD) message in case of downlink, and uplink channel in case of uplink. It is included in a Uplink Channel Descript (UCD) message. In the IEEE 802.16a communication system, the MCS level index is used as Downlink Interval Usage Code (DIUC) and Uplink Interval Usage Code (UIUC) according to downlink and uplink. In addition, when the channel state is poor, an additional bit is required to increase the reception probability of the signal. When the number of additionally inserted bits increases, the reception probability increases, but the resource efficiency (efficiency = information bits / transmission bits) ) Is lowered. In the IEEE 802.16a communication system, the number of bits to be additionally inserted according to the channel state is predetermined in order to ensure a preset reception probability.

Here, a process of transmitting a signal to the subscriber stations 110, 120, 130, 140, and 150 in the IEEE 802.16a communication system as shown in FIG. 1 will be described.

First, since the first subscriber station 110 has the best channel state, even if the base station 100 selects any MCS level among the five MCS levels and transmits the signal, the first subscriber station 110. ) May receive a signal transmitted from the base station 100 without error. However, in consideration of resource efficiency, the base station 100 selects MCS level 4 among the five MCS levels and transmits a signal to the first subscriber station 110. On the contrary, since the fifth subscriber station 150 has the worst channel state, the base station 100 should select MCS level 0, which is the strongest MCS level, and transmit a signal to the fifth subscriber station 150. The fifth subscriber station 150 can normally receive the signal.

In addition, in order to perform communication between the base station and the subscriber station, the base station and the subscriber station must transmit and receive signals using the same MCS level. If the MCS level used by the base station and the MCS level used by the subscriber station are different, signals transmitted and received between the base station and the subscriber station cannot be normally transmitted and received. Here, since a process of transmitting and receiving information on the MCS level determined between the base station and the subscriber station is not directly related, a detailed description thereof will be omitted.

Meanwhile, as described above, the common control information is information that should be received in common by all the subscriber stations served by the base station 100, that is, the first subscriber station 110 to the fifth subscriber station 150. MCS level 0, which is the strongest MCS level, is applied so that the first subscriber station 110 to the fifth subscriber station 150 can receive the subscriber station in the worst channel state, that is, the fifth subscriber station 150 normally. Must be sent.                         

Next, the common control information will be described.

Before describing the common control information, the DL (DownLink) _MAP message and UL (UpLink) _MAP message of the IEEE 802.16a communication system will be described as an example of the common control information. Information elements included in the DL_MAP message (IE) are shown in Table 2 below.

Syntax Size  Management Message Type = 2  8 bits  PHY Synchronization Field  PHY dependent  DCD Count  16 bits  Base Station ID  48 bits  Number of DL-MAP Information Elements n  Variable  for (i = 1; i <= n; i ++) {     DIUC  4 bits     Location Infomation  PHY dependent  }

As shown in Table 2, the DL_MAP message corresponds to a plurality of IEs, that is, a Management Message Type indicating a type of a transmitted message, and a modulation scheme and a demodulation scheme applied to a physical channel to acquire synchronization. A DCD count indicating a count corresponding to a configuration change of a downlink channel descriptive message including a PHY (PHYsical) synchronization, a downlink burst profile, and a base station identifier ( A base station ID indicating a base station identifier, a number of DL_MAP elements n indicating a number of elements existing after the base station ID, an MCS level index for an allocated radio resource block, that is, a DIUC and the Location information of the radio resource block is included.

In addition, IEs included in the UL_MAP message are shown in Table 3 below.

Syntax Size   Management Message Type = 3  8 bits   Uplink Channel ID  16 bits   UCD Count  16 bits   Number of UL-MAP Elements n  Variable   Allocation Start Time  32 bits   for (i = 1; i <= n; i ++) {       CID  16 bits       UIUC  4 bits       Location Info.  PHY dependent   }

As shown in Table 3, the UL_MAP message includes a plurality of IEs, that is, a management message type indicating a type of a transmitted message, an uplink channel ID indicating an uplink channel ID used, and an uplink burst. A UCD count indicating a count corresponding to a configuration change of an uplink channel descriptive message including a profile, a Number of UL_MAP Elements n indicating a number of elements existing after the UCD count, and uplink resource allocation start information. Allocation Start Time indicating, MCS level index for the allocated radio resource block, that is, UIUC and location information of the radio resource block, and connection identifier (CID) of the subscriber station to use the allocated radio resource block. : Connection ID).

Since the DL_MAP message and the UL_MAP message are common control information, the base station 100 is the MCS level 4 which is the strongest MCS level so that both the first subscriber station 110 to the fifth subscriber station 150 can receive normally. Send using. However, the common control information, that is, the DL_MAP message and the UL_MAP message are allocated by the base station 100 as well as information that all of the first subscriber station 110 to the fifth subscriber station 150 must receive in common. An MCS level index for a radio resource block and location information of the radio resource block are included.

That is, in the case of the DL_MAP message, PHY Synchronization, Downlink Channel Descriptive Information, DCD Count, Base Station ID, and Number of UL_MAP Elements n are both the first subscriber station 110 to the fifth subscriber station 150. Is the information that should be received in common, DIUC and Location Information is not the information that all of the first subscriber terminal 110 to the fifth subscriber terminal 150 should receive in common, but information that only the corresponding subscriber terminal should be received. In addition, in case of the UL_MAP message, an uplink channel ID, a UCD count, a number of UL_MAP elements n, and an Allocation Start Time must be commonly received by all of the first subscriber station 110 to the fifth subscriber station 150. Although the information is CID, UIUC, and Location Information, the first subscriber station 110 to the fifth subscriber station 150 are not the information that must be received in common, but only the subscriber station.

Next, a process of applying the AMC scheme in the IEEE 802.16a communication system will be described with reference to FIG. 2.                         

2 is a diagram schematically illustrating the application of the AMC scheme of a general IEEE 802.16a communication system.

Before describing FIG. 2, it is assumed that the structure of the general IEEE 802.16a communication system is the same as that of the IEEE 802.16a communication system described with reference to FIG. 1. As shown in FIG. 2, the base station 100 transmits the common control information 211 by applying the MCS level 0, and includes a first wireless resource including data targeted to the fourth subscriber station 140. 213 transmits by applying MCS level 1, and transmits a second wireless resource 215 including data targeting the first subscriber station 110 by applying MCS level 4, and transmits to third subscriber station 130. The third wireless resource 217 including the data targeting the Mx level 2 is transmitted by applying the MCS level 2, and the fourth wireless resource 219 including the data targeting the second subscriber station 120 is the MCS. Send with Level 3 applied. The common control information 211, that is, the DL_MAP message and the UL_MAP message, includes information on allocated radio resources, that is, allocation information on the first wireless resource 213 to the fourth wireless resource 219. The allocation information for the first radio resource 213 to the fourth radio resource 219 actually needs to be received only from corresponding subscriber stations, but is included in the common control information 211 so that the base station is the most powerful MCS level MCS. By applying level 0, allocation information for the first wireless resource 213 to the fourth wireless resource 219 is transmitted.

For example, as described with reference to FIG. 2, the base station 100 may provide information about a downlink radio resource block targeting only the first subscriber station 110 among the common control information, that is, the DL_MAP message and the UL_MAP message. DIUC, Location Information) and information on uplink radio resource block (CID, UIUC, Location Information) may be transmitted using MCS level 4, but the downlink radio resource block targeting only the first subscriber station 110 is used. Information about the information (DIUC, Location Information) and information about the uplink radio resource block (CID, UIUC, Location Information) is also included in the common control information and transmitted using MCS level 0.

As a result, the information on the downlink radio resource block (DIUC) and the information on the uplink radio resource block (CID, UIUC, Location Information) targeting only the first subscriber station 110 are unnecessarily strong. Modulation and coding is applied, which results in signaling overhead. Herein, a case in which only the first subscriber terminal 110 is targeted is described as an example. However, the second subscriber terminal 120 to the fourth subscriber terminal 120 may also be targeted. In the same way as targeting only), signaling overhead occurs. As described above, the transmission of the common control information by applying the strongest MCS level has a problem in that resource efficiency is lowered.

Accordingly, an object of the present invention is to provide an apparatus and method for transmitting and receiving common control information in a wireless communication system.

Another object of the present invention is to provide an apparatus and method for transmitting / receiving common control information in a wireless communication system by applying an AMC scheme corresponding to its characteristics.                         

Another object of the present invention is to provide an apparatus and method for transmitting and receiving common control information for maximizing resource efficiency in a wireless communication system.

The device proposed in the present invention; An apparatus for transmitting common control information from the base station to the plurality of subscriber stations in a wireless communication system having a plurality of subscriber stations in a base station area, comprising: a first transmission of the common control information to all of the plurality of subscriber stations; After generating the common control information to include information and second information transmitted to the subscriber stations according to channel states of the subscriber stations, the modulation and coding scheme (MCS) to be applied to the first information. and Coding Scheme) is determined as a MCS level having a minimum order modulation scheme and a minimum coding rate coding scheme among all MCS levels provided by the base station, and the MCS levels to be applied to the second information. MCS level adjusted by a preset level than the MCS levels corresponding to the respective channel states A controller for determining the control unit, an encoder for coding the first information and the second information with coding schemes corresponding to the MCS levels determined by the controller when the common control information is input, and the first information coded by the encoder. And a modulator for modulating second information in modulation schemes corresponding to MCS levels determined by the controller, and a transmitter for radio frequency processing and transmitting a signal output from the modulator.

Another apparatus proposed by the present invention; An apparatus for transmitting common control information from the base station to the plurality of subscriber stations in a wireless communication system having a plurality of subscriber stations in a base station area, the first control unit transmitting the common control information to all of the plurality of subscriber stations. After generating the common control information to include information and second information transmitted to the subscriber stations according to channel states of the subscriber stations, the modulation and coding scheme (MCS) to be applied to the first information. and Coding Scheme) is determined as the MCS level corresponding to the channel state of the subscriber station having the worst channel state among the plurality of subscriber stations, and the MCS levels to be applied to the second information channel of each of the subscriber stations. A controller for determining MCS levels corresponding to states and the common control information is input; An encoder for coding the first information and the second information with coding schemes corresponding to the MCS levels determined by the controller, and the first information and the second information coded by the encoder to the MCS levels determined by the controller. And a transmitter for modulating and transmitting a signal output from the modulator and a modulator for modulating with corresponding modulation schemes.

Another device proposed by the present invention; An apparatus for receiving common control information transmitted from the base station to the plurality of subscriber stations in a wireless communication system having a plurality of subscriber stations in a base station area, wherein all of the plurality of subscriber stations receive by demultiplexing a received signal. A receiver for detecting the common control information comprising first information, second information received by each of the subscriber stations according to channel states of the subscriber stations, and the common information in the base station; A demodulator corresponding to a modulation scheme corresponding to a modulation and coding scheme (MCS) level applied to the demodulation scheme and demodulating correspondingly to modulation schemes corresponding to MCS levels applied to the second information; The demodulated common control information corresponds to the MCS level applied to the first information by the base station. And a decoder to decode according to the coding scheme and to decode corresponding to the decoding schemes corresponding to the MCS levels applied to the second information.

The method proposed in the present invention; A method of transmitting common control information from the base station to the plurality of subscriber stations in a wireless communication system having a plurality of subscriber stations in a base station area, the first control information being transmitted to all of the plurality of subscriber stations. Generating the common control information to include information and second information respectively transmitted to the subscriber stations according to channel states of the subscriber stations, wherein the first information includes all modulations provided by the base station. And information transmitted by applying an MCS level having a minimum order modulation scheme and a minimum coding rate coding scheme among modulation and coding scheme (MCS) levels, wherein the second information is a channel of each of the subscriber stations. MCS level adjusted by a preset level than MCS levels corresponding to states By applying the features a deulim information to be transmitted.

Another method proposed by the present invention; A method of transmitting common control information from the base station to the plurality of subscriber stations in a wireless communication system having a plurality of subscriber stations in a base station area, the first control information being transmitted to all of the plurality of subscriber stations. Generating the common control information to include information and second information respectively transmitted to the subscriber stations according to channel states of the subscriber stations, wherein the first information is selected from among the plurality of subscriber stations. Information transmitted by applying a modulation and coding scheme (MCS) level corresponding to a channel state of a subscriber station having the worst channel state, and the second information corresponds to a channel state of each of the subscriber stations. The information is transmitted by applying one MCS level.

Another method proposed by the present invention is; A method of receiving common control information transmitted from the base station to the plurality of subscriber stations in a wireless communication system having a plurality of subscriber stations in a base station area, wherein all of the plurality of subscriber stations are received by demultiplexing a received signal. Detecting the common control information comprising first information and second information received by each of the subscriber stations according to channel conditions of the subscriber stations; and transmitting the common control information to the base station by the first information. Decoding the first information by demodulating and decoding corresponding to a modulation and coding scheme (MCS) level applied to the modulation and coding scheme (MCS) level, and after decoding the first information, Modulation scheme corresponding to MCS levels in which common control information is applied to the second information by the base station In correspondence to the coding scheme and the demodulation and decoding it is characterized in that it comprises the step of decoding the second information.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that in the following description, only parts necessary for understanding the operation according to the present invention will be described, and descriptions of other parts will be omitted so as not to distract from the gist of the present invention.

According to the present invention, common control information (CCI) that all subscriber stations (SS) must receive in common in a wireless communication system is adaptively adapted to correspond to the characteristics of the common control information and the channel state of the subscriber stations. The present invention proposes an apparatus and method for increasing resource efficiency by transmitting a modulation and coding (AMC) scheme. Orthogonal frequency division multiplexing (OFDM) to a wireless metropolitan area network (MAN) communication system, which is a broadband wireless access (BWA) communication system, in the following description of the present invention. IEEE (Institute of Electrical and Electronics) applying Orthogonal Frequency Division Multiplexing (OFDM) method and Orthogonal Frequency Division Multiplexing Access (OFDMA) method Engineers) The 802.16a communication system will be described as an example of the wireless communication system.

Here, the AMC method will be described once again.

The AMC scheme is a scheme for transmitting signals by variously applying a modulation and coding scheme (MCS) according to channel conditions between a base station and subscriber stations. That is, the AMC scheme refers to a signal transmission scheme that determines different channel modulation schemes and coding schemes according to channel states between a cell, that is, a base station and subscriber stations, thereby improving efficiency of the entire cell. The AMC scheme has a plurality of modulation schemes and a plurality of coding schemes, and modulates and codes a channel signal by combining the modulation schemes and coding schemes. Typically, each combination of the modulation schemes and coding schemes is referred to as the MCS, and a plurality of MCSs can be defined from level 1 to level N according to the number of MCSs. That is, the AMC scheme is to adaptively determine the level of the MCS according to the channel state between the base station and the subscriber station to improve the overall system efficiency of the base station.

Next, a process of applying the AMC scheme according to the first embodiment of the present invention in the IEEE 802.16a communication system will be described with reference to FIG. 3.

3 is a diagram schematically illustrating the application of the AMC scheme of the IEEE 802.16a communication system according to the first embodiment of the present invention.

Before describing FIG. 3, it is assumed that the IEEE 802.16a communication system has the same structure as that of the IEEE 802.16a communication system of FIG. 1 described in the prior art, and only one subscriber station, that is, the sixth subscriber. It is assumed that only the point that the terminal (not shown) exists at the same position as the subscriber terminal 130 is different. As described with reference to FIG. 1, the channel state of the first subscriber station 110 closest to the base station (BS) 100 is the best, and the fifth subscriber is farthest from the base station 100. The channel state of the terminal 150 is the worst.

In addition, as described with reference to FIG. 1, the channel state is divided into five states, that is, a 'good' state, a 'good' state, a 'normal' state, a 'poor' state, and a 'poor' state. Let's do it. In addition, it is assumed that the IEEE 802.16a communication system has five MCS levels from MCS level 0 to MCS level 4 as described in Table 1 of the prior art.

The common control information may be a DL (DownLink) _MAP message and a UL (UpLink) _MAP message as described in Tables 2 and 3 of the prior art part, and Hybrid Automatic Retransmission Request (HARQ). Or hereinafter referred to as 'HARQ') _ MAP message. Here, the HARQ_MAP message includes a compact DL_MAP message and a compact UL_MAP message including some of information elements (IE) hereinafter included in the DL_MAP message and the UL_MAP message. It includes. IEs included in the compact DL_MAP message and the compact UL_MAP message are not directly related to the present invention, and thus a detailed description thereof will be omitted. As described in the prior art, the DL_MAP message has a PHY (PHYsical) synchronization and a downlink channel decode (PHY) set corresponding to a modulation scheme and a demodulation scheme applied to a physical channel to obtain synchronization. DCD: a DCD Count indicating a count corresponding to a configuration change of a DCD message including a Downlink Channel Descript (hereinafter referred to as a 'DCD') information and a downlink burst profile; The base station ID indicating the base station identifier and the number of UL_MAP elements n indicating the number of elements existing after the base station ID should be commonly received by all subscriber stations serving by the base station 100. Information, but the MCS level index for the allocated radio resource block, that is, downlink I nterval usage code) and location information of the radio resource block are not information that all the subscriber stations should receive in common, but information that only the corresponding subscriber station should receive.

In addition, the UL_MAP message includes an Uplink Channel ID indicating an Uplink Channel ID and an Uplink Channel Descript (UCD) including an uplink burst profile. The UCD count indicating the count corresponding to the configuration change of the message, the Number of UL_MAP Elements n indicating the number of elements existing after the UCD count, and the Allocation Start Time indicating the uplink resource allocation start information are described above. Information that all subscriber stations must receive in common, but MCS level index for the allocated radio resource block, that is, Uplink Interval Usage Code (UIUC), location information of the radio resource block, Location Information and the allocated radio resource Connection ID (CID: Connection ID) of the subscriber station to use the block Be) is a need to receive only the information as the information that must be received by all the subscriber stations in common the subscriber station. In addition, the HARQ_MAP message is not information that all subscriber stations must receive in common, but information that only subscriber stations having the same channel state should receive.

Referring to FIG. 3, as shown in FIG. 3, the base station 100 transmits common control information 311 so that the information that all the subscriber stations served by the base station 100 must receive is the most robust. MCS level 0, which is an MCS level, is applied and transmitted, and information that should be received only by the corresponding subscriber station is transmitted by applying the MCS level according to the channel state of the corresponding subscriber station. Since the MCS level allocation for the information that only the corresponding subscriber station of the common control information 311 should receive will be described below, its detailed description will be omitted.

The base station 100 transmits the first wireless resource 313 including data targeted to the fourth subscriber station 140 by applying MCS level 1, and targets the first subscriber station 110. The second wireless resource 315 including the transmits by applying the MCS level 4. In addition, the base station 100 transmits the third wireless resource 317 including data targeting the third subscriber station 130 and the sixth subscriber terminal by applying MCS level 2, and the second subscriber station ( The fourth radio resource 319 including data targeted to 120 is transmitted by applying MCS level 3. Here, some of the third wireless resources 317 are allocated to the third subscriber station 130 and others are allocated to the sixth subscriber terminal, so that a connection identifier (CID) is used to distinguish data from each other. Include and send.

Meanwhile, as described above, the MCS level of the information applied for each subscriber station except for the information that all subscriber stations need to be received in the common control information 311 will be described as follows.

First, information received only by the corresponding subscriber station from the common control information 311 may determine the MCS level according to the corresponding subscriber station channel state. However, even though only the corresponding subscriber station information should be received, high reliability must be ensured compared to general data that is not control information. Therefore, the present invention applies a level one level lower than the MCS level corresponding to the channel state of the corresponding subscriber station. To transmit. Of course, it is also possible to transmit by applying the MCS level corresponding to the channel state of the subscriber station, but only in terms of reliability is lower than when applying the low level of the first level.

Since the base station 100 needs to receive the first wireless resource allocation information 321 only by the fourth subscriber station 140, the base station 100 transmits MCS level 0 by applying the second wireless resource allocation information 323 to the first subscriber station. Since only need to be received by 110, apply by applying the MCS level 3, and the third radio resource allocation information 325 is transmitted only by the third subscriber station 130 and the sixth subscriber terminal, so that the transmission by applying MCS level 1 Since the fourth radio resource allocation information 327 only needs to be received by the second subscriber station 120, the fourth radio resource allocation information 327 is transmitted by applying the MCS level 2.

That is, the present invention classifies the characteristics according to whether all the subscriber stations should receive the common control information 311 or only the corresponding subscriber stations, so that the information that all the subscriber stations must receive is the strongest MCS level, that is, the MCS. Transmitting by applying the level 0, and the information that should be received only by the subscriber station is transmitted by applying a level that is set in advance than the MCS level corresponding to the channel state of the subscriber station, for example, one level lower than that of the subscriber station. Will be increased.

3 illustrates the application of the AMC scheme of the IEEE 802.16a communication system according to the first embodiment of the present invention. Next, the AMC of the IEEE 802.16a communication system according to the second embodiment of the present invention will be described with reference to FIG. The application of the method will be described.

9 is a diagram schematically showing the application of the AMC scheme of the IEEE 802.16a communication system according to a second embodiment of the present invention.

Before describing FIG. 9, it is assumed that the IEEE 802.16a communication system has the same structure as described with reference to FIG. That is, as described with reference to FIG. 3, the channel state of the first subscriber station 110 closest to the base station 100 is the best, and the fifth subscriber station 150 farthest from the base station 100 is present. The channel condition of is the worst. In addition, the sixth subscriber terminal is the same as that described in FIG. 3 that the third subscriber terminal 130 exists at the same position.

On the other hand, in the first embodiment of the present invention, there is no separate definition for the information that all the subscriber stations should receive in common among the common control information. However, in order for the subscriber stations to normally receive radio resource information, which is allocation information for radio resources allocated to each of the subscriber stations, decoding information for normally decoding the radio resource allocation information must be included in the common control information. That is, since each of the radio resource allocation information is encoded according to the MCS level applied according to the channel state of the corresponding subscriber station, the size and position occupied by each of the radio resource allocation information also differ. The size and location of the information must be informed via the common control information. Then, the subscriber station reads the decoding information and decodes the radio resource allocation information at a corresponding MCS level at a corresponding size of the position of the corresponding radio resource allocation information. Here, the decoding information for the radio resource allocation information indicates the location information and the size information of the radio resource allocation information corresponding to the MCS level and the MCS level.

Referring to FIG. 9, the second embodiment of the present invention applies the AMC method in substantially the same manner as in the first embodiment of the present invention, except that the common control information described in FIG. The only difference is that the decoding information 929 for the radio resource allocation information is added to 311). In addition, since the MCS level applied to the actual radio resource information is different as described above, unlike in FIG. 3, the first radio resource allocation information 321 to the fourth radio resource allocation information 327 They differ only in the size, ie, the positions are shown differently. Therefore, detailed description of the same parts as in FIG. 3 will be omitted.

Next, a transmitter structure of an IEEE 802.16a communication system for performing a function in an embodiment of the present invention will be described with reference to FIG. 4.

4 is a diagram schematically illustrating a transmitter structure of an IEEE 802.16a communication system for performing a function of an embodiment of the present invention.

Referring to FIG. 4, first, the transmitter, that is, the base station, includes a radio resource allocator 410, an encoder 411, an interleaver 413, and a symbol mapper 415. ), An AMC controller 417, a serial to parallel converter 419, a pilot symbol inserter 421, and an Inverse Fast Fourier Transform (IFFT). (Hereinafter, referred to as IFFT) 423, parallel to serial converter 425, guard interval inserter 427, and digital / analog converter (digital to analog converter) 429 and a radio frequency (RF) processor (431).

First, the radio resource allocator 410 allocates downlink and uplink resources to receivers, that is, subscriber stations, generates common control information corresponding to the allocated downlink and uplink resources, and generates the encoder ( 411). The process of allocating the downlink and uplink resources for the subscriber stations by the radio resource allocator 410 is not directly related to the present invention, and thus detailed description thereof will be omitted herein. The encoder 311 receives the common control information, codes the data in a coding scheme according to the control of the AMC controller 417, and outputs the coded information to the interleaver 313.

The AMC controller 417 decides to apply a coding scheme corresponding to the strongest MCS level to information that all subscriber stations of the common control information should receive, and information that only the corresponding subscriber station of the common control information should receive. For, it is determined to apply a coding scheme corresponding to the MCS level one level lower than the MCS level corresponding to the channel state of the subscriber station. Here, the coding scheme is assumed to be a coding rate as an example. The interleaver 413 interleaves the preset interleaving method and outputs the interleaver 413 to the symbol mapper 415. In this case, the interleaving scheme may be a random interleaving scheme.

The symbol mapper 415 modulates the coded bits output from the interleaver 413 in a modulation scheme according to the control of the AMC controller 417 to generate modulation symbols, and then converts the serial / parallel converter. Output to (419). Here, the modulation scheme may be a Quadrature Phase Shift Keying (QPSK) scheme or a Quadrature Amplitude Modulation (16QAM) scheme. The AMC controller 417 may provide information on information that all subscriber stations should receive from the common control information. It is decided to apply a modulation scheme corresponding to the strongest MCS level, and for information that only the corresponding subscriber station needs to receive among the common control information, it corresponds to an MCS level one level lower than the MCS level corresponding to the channel state of the corresponding subscriber station. Determine to apply the modulation scheme.

The serial / parallel converter 419 inputs and converts the parallel pair symbols output from the symbol mapper 415 to the pilot symbol inserter 421. The pilot symbol inserter 421 inserts pilot symbols into the parallel-converted modulated symbols output from the serial / parallel converter 419 and outputs the pilot symbols to the IFFT unit 423.

The IFFT unit 423 inputs the signal output from the pilot symbol inserter 421 to perform an N-point IFFT and then outputs it to the parallel / serial converter 425. The parallel / serial converter 425 inputs the signal output from the IFFT unit 423, serially converts the signal, and outputs the serial signal to the guard interval inserter 427. The guard interval inserter 427 inputs the signal output from the parallel / serial converter 425, inserts a guard interval signal, and outputs the guard interval signal to the digital / analog converter 429. In this case, the guard interval is inserted to remove interference between the OFDM symbols transmitted at the previous OFDM symbol time and the current OFDM symbols to be transmitted at the current OFDM symbol time when the OFDM symbol is transmitted. In addition, the guard interval is a 'Cyclic Prefix' method of copying the last constant samples of the OFDM symbols in the time domain and inserting them into a valid OFDM symbol, or the first constant samples of the OFDM symbols in the time domain. It can be used in a 'Cyclic Postfix' method of copying and inserting the valid OFDM symbol.

The digital-to-analog converter 429 inputs the signal output from the guard interval inserter 427, converts the analog signal, and outputs the analog signal to the RF processor 431. Here, the RF processor 431 includes components such as a filter and a front end unit, and transmits the signal output from the digital-to-analog converter 429 on actual air. After the RF process, the transmission is performed on the air through a Tx antenna.

4 illustrates a structure of a transmitter of an IEEE 802.16a communication system for performing a function in an embodiment of the present invention. Next, an IEEE 802.16a for performing a function in an embodiment of the present invention will be described with reference to FIG. The receiver structure of the communication system will be described.

5 is a diagram schematically illustrating a receiver structure of an IEEE 802.16a communication system for performing a function in an embodiment of the present invention.                     

Referring to FIG. 5, first, a receiver of the OFDM communication system, for example, a subscriber station includes an RF processor 511, an analog / digital converter 513, and a guard interval remover. 515, serial / parallel converter 517, Fast Fourier Transform (FFT), 519, equalizer 521, pilot A pilot symbol extractor 523, a channel estimator 525, a parallel / serial converter 527, a symbol demapper 529, and a deinterleaver 531, a decoder 533, and an AMC controller 535.

First, a signal transmitted from a transmitter, for example, a base station, of the IEEE 802.16a communication system as described with reference to FIG. 4 is received through a Rx antenna in the form of a multipath channel and noise added thereto. . The signal received through the receive antenna is input to the RF processor 511, and the RF processor 511 down converts the signal received through the receive antenna to an intermediate frequency (IF) band. And then output to the analog-to-digital converter 513. The analog / digital converter 513 digitally converts the analog signal output from the RF processor 511 and outputs the digital signal to the guard interval remover 515.

The guard interval remover 515 removes the guard interval signal by inputting the signal output from the analog / digital converter 513 and outputs the signal to the serial / parallel converter 517. The serial / parallel converter 517 inputs a serial signal output from the guard interval eliminator 515 to perform parallel conversion and outputs the serial signal to the FFT unit 519. The FFT unit 519 performs an N-point FFT on the signal output from the serial / parallel converter 517 and then outputs the signal to the equalizer 521 and the pilot symbol extractor 523. The equalizer 521 inputs a signal output from the FFT 519 and performs channel equalization and outputs the same to the parallel / serial converter 527. The parallel / serial converter 527 inputs a parallel signal output from the equalizer 521 to serially convert and output the serial signal to the symbol demapper 529.

On the other hand, the signal output from the FFT 519 is input to the pilot symbol extractor 523, the pilot symbol extractor 523 detects the pilot symbols from the signal output from the FFT 519, The detected pilot symbols are output to the channel estimator 525. The channel estimator 525 performs channel estimation using the pilot symbols output from the pilot symbol extractor 523 and outputs the channel estimation result to the equalizer 521. The receiver of the OFDM communication system generates a CQI corresponding to a channel estimation result of the channel estimator 525, and transmits the generated CQI to a transmitter of the OFDM communication system through a channel quality information transmitter (not shown). Send.

The symbol demapper 529 demodulates the signal output from the parallel / serial converter 527 to a demodulation method corresponding to a modulation method applied by a transmitter of the IEEE 802.16a communication system, and then decodes the signal to the deinterleaver 531. Output Here, the information on the modulation scheme applied by the transmitter of the IEEE 802.16a communication system is provided from the AMC controller 535, the AMC controller 535 is not shown in Figure 5, but the transmitter of the IEEE 802.16a communication system Receive information on a separate modulation scheme from the. The deinterleaver 531 deinterleaves the signal output from the symbol demapper 529 by a deinterleaving method corresponding to an interleaving method applied by a transmitter of the IEEE 802.16a communication system, and then the decoder 533. )

The decoder 533 decodes a signal output from the deinterleaver 531 by a decoding method corresponding to a coding method applied by a transmitter of the IEEE 802.16a communication system, and then outputs it as common control information transmitted from a transmitting side. Here, the information on the coding scheme applied by the transmitter of the IEEE 802.16a communication system is provided from the AMC controller 535, the AMC controller 535 is not shown in Figure 5, but separate from the transmitter of the OFDM communication system It is provided with information about the coding scheme of.

5 illustrates a receiver structure of an IEEE 802.16a communication system for performing a function of an embodiment of the present invention. Next, the IEEE 802.16a according to the first and second embodiments of the present invention will be described with reference to FIG. A common control information transmission process of the communication system will be described.

6 is a flowchart illustrating a process of transmitting common control information in the IEEE 802.16a communication system according to the first and second embodiments of the present invention.

Referring to FIG. 6, first, a transmitter, that is, a base station, of an IEEE 802.16a communication system allocates downlink and uplink resources to subscriber stations in step 611, and common to the allocated downlink and uplink resources. After the control information is generated, the process proceeds to step 613. In step 613, the base station determines the MCS level to be applied to the common control information and proceeds to step 615. As described above, the MCS level for the common control information is determined to be the strongest MCS level for information that all the subscriber stations of the common control information must receive, and only the corresponding subscriber station among the common control information should be received. Information to be determined is determined to be one level lower than the MCS level corresponding to the channel state of the subscriber station. Particularly, in the second embodiment of the present invention, the common control information includes information that only the corresponding subscriber terminal should receive, that is, decoding information for decoding the radio resource allocation information normally, and the reason for including the decoding information is described above. This is because each of the radio resource allocation information is encoded at a different MCS level as described.

In step 615, the base station modulates and codes the common control information according to the determined MCS level, and then proceeds to step 617. In step 617, the base station transmits the modulated and coded common control information to the subscriber stations through the downlink and ends.

6 illustrates a process of transmitting common control information of the IEEE 802.16a communication system according to the first and second embodiments of the present invention. Next, referring to FIG. 7, the first and second embodiments of the present invention will be described. A process of receiving common control information of the IEEE 802.16a communication system will be described.                     

7 is a flowchart illustrating a process of receiving common control information of the IEEE 802.16a communication system according to the first and second embodiments of the present invention.

Referring to FIG. 7, the receiver of the IEEE 802.16a communication system, that is, the subscriber station, receives the downlink signal in step 711 and proceeds to step 713. In step 713, the subscriber station detects common control information by multiplexing the received downlink signal and proceeds to step 715. In particular, in the second embodiment of the present invention, decoding information for decoding radio resource allocation information is included in the common control information. In step 715, the subscriber station demodulates and decodes the detected common control information corresponding to the MCS level applied by the base station. In particular, according to the second embodiment of the present invention, step 717 after demodulating and decoding corresponding to the MCS level applied by the base station by the corresponding size at the position of the radio resource allocation information that the subscriber station itself should decode corresponding to the decoding information. Proceed to In this case, the subscriber station can more reliably decode the radio resource allocation information. In step 717, the subscriber station determines whether decryption of the common control information is successful.

If the decryption of the common control information is successful, the subscriber station proceeds to step 719. In step 719, the subscriber station terminates after performing an operation corresponding to the common control information, that is, an operation such as receiving data through a radio resource area corresponding to radio resource information included in the common control information. If the decoding of the common control information is not successful in step 719, the subscriber station proceeds to step 721. In step 721, the subscriber station terminates after discarding the decrypted information.

Meanwhile, as described above, the IEEE 802.16a communication system is a communication system using the OFDM method or the OFDMA method, and the common control information transmission and reception in the IEEE 802.16a communication system when the OFDMA method is used will be described with reference to FIG. 8. Let's explain.

8 is a diagram illustrating a frame structure of an IEEE 802.16a communication system according to a first embodiment of the present invention.

Referring to FIG. 8, the horizontal axis illustrated first represents an OFDMA symbol number, and the vertical axis represents a sub-channel number. As illustrated in FIG. 8, one OFDMA frame includes a plurality of OFDMA symbols, for example, eight OFDMA symbols, and one OFDMA symbol includes a plurality of OFDM symbols, for example, N sub-carrier signals. It is composed. Here, the subchannel refers to a channel composed of a predetermined number of subcarriers. In addition, as described above, the common control information includes a DL_MAP message, an UL_MAP message, or an HARQ_MAP message. In FIG. 8, the case where the common control information includes the DL_MAP message and the UL_MAP message will be described as an example. .

In FIG. 8, the base station 100 transmits common control information and user data to the third subscriber station 130 having a 'normal' channel state, so that the third subscriber station 130 does this. In this case, the first subscriber station 110 transmits user data on the uplink by transmitting common control information to the first subscriber station 110 having a channel state of 'best'. will be.

First, the base station 100 connects with the user data 815-1 of the third subscriber station 130 including the connection identifier A using the same level of quality of service (QoS) and the same MCS level. User data 815-2 of the sixth subscriber terminal including the identifier B is allocated to a third downlink burst 815. In the same way, the base station 100 allocates the user data and the connection identifier of the subscriber station for each downlink burst required within one OFDMA frame within the MCS level supported by the IEEE 802.16a communication system.

In addition, the base station 100 transmits a downlink burst, that is, a third downlink burst, transmitted to the third subscriber station 130 in the third downlink burst allocation information 813 in the DL_MAP message 811 which is common control information. MCS level and location information to be applied to 815, that is, offset information of a symbol unit and a subcarrier frequency allocation unit capable of distinguishing the downlink burst are mapped. Although not separately illustrated in FIG. 8, in the second embodiment of the present invention, decoding information for decoding radio resource allocation information in the common control information, that is, MCS level and radio resource allocation information corresponding to the MCS level It includes location information and size information. The base station 100 then codes and modulates the DL_MAP message 812 and downlink bursts to the corresponding MCS level and transmits them to subscriber stations.

In the above, the process of transmitting common control information and user data to the third subscriber station 130 by the base station 100 has been described. Next, the third subscriber station 130 transmits from the base station 100. A process of receiving common control information and user data will be described.                     

First, the third subscriber station 130 receives a downlink signal and detects common control information from the received downlink signal. That is, the third subscriber station 130 applies the strongest MCS level to the detected common control information, so that all the subscriber stations must first receive the DL_MAP message as described in Table 2, namely, Phy Synchronization, DCD Count, Base Station ID, and Number of DL_MAP Elements n are detected. Thereafter, the third subscriber station 130 has the detected common control information in order to obtain downlink burst allocation information for downlink bursts, which is greater than the MCS level corresponding to the channel state of the third subscriber station 130. Apply a lower MCS level to modulate and decode.

In detail, the third subscriber station 130 decodes the first downlink burst allocation information by applying an MCS level one level lower than the MCS level corresponding to the channel state of the third subscriber station 130. . However, since the MCS level applied to the first downlink burst allocation information is different, decoding fails and discards the allocation information. In this way, the third subscriber station 130 decodes the second downlink burst allocation information, the third downlink burst allocation information 813 and the fourth downlink burst allocation information. Since only the third downlink burst allocation information 813 is applied with the same MCS level, only the third downlink burst allocation information 813 is normally decoded. Accordingly, the third subscriber station 130 accesses the downlink burst according to the third downlink burst allocation information 813, that is, the third downlink burst 815, so that the third subscriber station 130 has its own channel. Demodulate user data at the MCS level equal to the MCS level corresponding to the state. In addition, although not separately illustrated in FIG. 8, in the second embodiment of the present invention, the third subscriber station 130 may include third downlink burst allocation information indicating the position of the third downlink burst 815. Decoded information for decoding 813 is detected from the common information to detect the location and size of downlink burst allocation information having the MCS level applied to the third subscriber station 130 itself. Accordingly, the third subscriber station 130 decodes the third downlink burst allocation information 813 reliably in correspondence with the decoding information. That is, when the third subscriber station 130 searches for the same MCS level as the MCS level of the third subscriber station 130 in the decoding information and decodes a corresponding position, the third downlink burst allocation information. 813 is normally decoded.

Here, in demodulating the user data, the third subscriber station 130 should refer to its own connection identifier, that is, connection identifier A.

The uplink burst allocation information can be detected in the same manner as in the downlink burst allocation information, which will be described in detail as follows.

First, the base station 100 allocates a first uplink burst 816 to the first subscriber terminal 110 to transmit user data on the uplink. That is, the base station 100 may distinguish MCS level information and location information of the first uplink burst 816, that is, the uplink burst, together with the connection identifier C of the first subscriber station 110 in the UL_MAP message. The offset information of the symbol unit and the subcarrier frequency allocation unit may be mapped. Then, the base station 100 codes and modulates the UL_MAP message 811 to the corresponding MCS level and transmits it to the subscriber stations.

Accordingly, the first subscriber station 110 receives a downlink signal and detects common control information from the received downlink signal. That is, the first subscriber station 110 applies the strongest MCS level to the detected common control information, so that all the subscriber stations must first receive the UL_MAP message as described in Table 3, that is, the Upink CHannel ID and the like. , UCD Count, Allocation Start Time, and Number of UL_MAP Elements n are detected. In addition, although not separately illustrated in FIG. 8, in the second embodiment of the present invention, the location information and the size of each of the decoding information, that is, MCS level and uplink burst allocation information corresponding to the MCS level, are included in the common information. Contains information. Thereafter, the first subscriber station 110 has a value of 1 than the MCS level corresponding to the channel state of the first subscriber station 110 in the detected common control information to obtain uplink burst allocation information for uplink bursts. Apply a lower MCS level to modulate and decode.

In detail, the first subscriber station 110 decodes the first uplink burst allocation information by applying an MCS level one level lower than the MCS level corresponding to the channel state of the first subscriber station 110. . Since the MCS level applied to the first uplink burst allocation information and the MCS level one level lower than the MCS level corresponding to the channel state of the first subscriber station 110 are the same, the first uplink burst allocation information Can be decrypted normally. Accordingly, the first subscriber station 110 can use the uplink burst according to the first uplink burst allocation information 814, that is, the first downlink burst 816.

In addition, although not separately illustrated in FIG. 8, in the second embodiment of the present invention, the first subscriber station 110 includes a first indicating the position of the first uplink burst 816 included in common information. When decoding information for decoding uplink burst allocation information 814 is detected, uplink burst allocation information having the MCS level to be received by the first subscriber station 110 itself corresponding to the decoding information, that is, the first Decode uplink burst allocation information 814.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims, but also by the equivalents of the claims.

 As described above, the present invention provides an MCS level in which a characteristic is classified and applied into common control information for all subscriber stations in general and information only for specific subscriber stations among all subscriber stations in a wireless communication system. Differentiated transmission has the advantage of maximizing the efficiency of radio resources. In this way, there is an advantage in that the system yield of the wireless communication system is increased by minimizing the amount of radio resources used for common control information transmission by using the spare radio resources for transmitting other data.

Claims (38)

A method of transmitting common control information from the base station to the plurality of subscriber stations in a wireless communication system having a plurality of subscriber stations in a base station area, the method comprising: Generating the common control information such that the common control information includes first information transmitted to all of the plurality of subscriber stations and second information transmitted to the subscriber stations according to channel states of the subscriber stations. Process, The first information is information transmitted by applying an MCS level having a minimum order modulation scheme and a minimum coding rate coding scheme among all modulation and coding scheme (MCS) levels provided by the base station, The second information is information transmitted by applying MCS levels adjusted by a preset level rather than MCS levels corresponding to channel states of each of the subscriber stations. The method of claim 1, The first information includes MCS levels applied to the second information, and location and size information of information corresponding to each of the MCS levels. The method of claim 2, The MCS levels adjusted by a predetermined level than the MCS levels corresponding to the channel state of each of the subscriber stations are the same MCS levels as the MCS levels corresponding to the channel state of each of the subscriber stations or the subscriber stations. MCS levels corresponding to each channel state have modulation orders of lower order than respective modulation schemes, and the coding schemes of each of the set level adjusted MCS levels are MCS corresponding to the channel state of each of the specific subscriber stations. Said MCS levels having lower coding rates than the respective coding schemes. A method of transmitting common control information from the base station to the plurality of subscriber stations in a wireless communication system having a plurality of subscriber stations in a base station area, the method comprising: Generating the common control information such that the common control information includes first information transmitted to all of the plurality of subscriber stations and second information transmitted to the subscriber stations according to channel states of the subscriber stations. Process, The first information is information transmitted by applying a modulation and coding scheme (MCS) level corresponding to the channel state of the subscriber station having the worst channel state among the plurality of subscriber stations, The second information is information transmitted by applying MCS levels corresponding to channel states of each of the subscriber stations. The method of claim 4, wherein Wherein the first information includes MCS levels applied to the second information, and location and size information of information corresponding to each of the MCS levels. An apparatus for transmitting common control information from the base station to the plurality of subscriber stations in a wireless communication system having a plurality of subscriber stations in a base station area, the apparatus comprising: The common control information is generated such that the common control information includes first information transmitted to all of the plurality of subscriber stations and second information transmitted to the subscriber stations according to channel states of the subscriber stations. Thereafter, a modulation and coding scheme (MCS) level to be applied to the first information is changed to an MCS level having a minimum order modulation scheme and a minimum coding rate coding scheme among all MCS levels provided by the base station. A controller for determining the MCS levels to be applied to the second information as MCS levels adjusted by a predetermined level than MCS levels corresponding to channel states of each of the subscriber stations; An encoder for coding the first information and the second information in coding schemes corresponding to MCS levels determined by the controller when the common control information is input; A modulator for modulating the first information and the second information coded by the encoder with modulation schemes corresponding to MCS levels determined by the controller; And a transmitter for radio frequency processing and transmitting the signal output from the modulator. The method of claim 6, The first information may include MCS levels applied to the second information, and location and size information of information corresponding to each of the MCS levels. The method of claim 6, The MCS levels adjusted by a predetermined level than the MCS levels corresponding to the channel state of each of the subscriber stations are the same MCS levels as the MCS levels corresponding to the channel state of each of the subscriber stations or the subscriber stations. MCS levels corresponding to each channel state have modulation orders of lower order than respective modulation schemes, and the coding schemes of each of the set level adjusted MCS levels are MCS corresponding to the channel state of each of the specific subscriber stations. Said MCS levels having lower coding rates than the respective coding schemes. An apparatus for transmitting common control information from the base station to the plurality of subscriber stations in a wireless communication system having a plurality of subscriber stations in a base station area, the apparatus comprising: The common control information is generated such that the common control information includes first information transmitted to all of the plurality of subscriber stations and second information transmitted to the subscriber stations according to channel states of the subscriber stations. Subsequently, a modulation and coding scheme (MCS) level to be applied to the first information is determined as an MCS level corresponding to a channel state of a subscriber station having the worst channel state among the subscriber stations. A controller for determining MCS levels to be applied to 2 information as MCS levels corresponding to channel states of the subscriber stations; An encoder for coding the first information and the second information in coding schemes corresponding to MCS levels determined by the controller when the common control information is input; A modulator for modulating the first information and the second information coded by the encoder with modulation schemes corresponding to MCS levels determined by the controller; And a transmitter for radio frequency processing and transmitting the signal output from the modulator. The method of claim 9, The first information may include MCS levels applied to the second information, and location and size information of information corresponding to each of the MCS levels. A method of receiving common control information transmitted from the base station to the plurality of subscriber stations in a wireless communication system having a plurality of subscriber stations in a base station area, Demultiplexing a received signal to detect the common control information including first information received by all of the plurality of subscriber stations and second information received by each of the subscriber stations according to channel conditions of the subscriber stations; Process, Decoding the first information by demodulating and decoding the common control information corresponding to a modulation scheme and a coding scheme corresponding to a modulation and coding scheme (MCS) level applied to the first information by the base station; and, Decoding the first information, and then demodulating and decoding the common control information corresponding to a modulation scheme and a coding scheme corresponding to MCS levels applied by the base station to the second information to decode the second information. Said method comprising: a. The method of claim 11, The first information includes MCS levels applied to the second information, and location and size information of information corresponding to each of the MCS levels. The method of claim 12, The MCS level applied to the first information is characterized in that the MCS level corresponding to the channel state of the subscriber station having the worst channel state of the plurality of subscriber stations. The method of claim 11, The MCS level applied to the first information is characterized in that the MCS level having a minimum order modulation method and a coding method of the minimum coding rate of all MCS levels provided by the base station. The method of claim 14, The MCS levels applied to the second information are MCS levels adjusted by a predetermined level than MCS levels corresponding to channel states of each of the subscriber stations. The method of claim 14, The MCS levels applied to the second information are MCS levels corresponding to channel states of each of the subscriber stations. The method of claim 13, The MCS levels applied to the second information are MCS levels adjusted by a predetermined level than MCS levels corresponding to channel states of each of the subscriber stations. The method of claim 13, The MCS levels applied to the second information are MCS levels corresponding to channel states of each of the subscriber stations. The method of claim 15, MCS levels adjusted by a predetermined level than MCS levels corresponding to the channel state of each of the subscriber stations are of a lower order modulation scheme than the modulation schemes of each of the MCS levels corresponding to the channel state of each of the subscriber stations. And the coding schemes of each of the set level adjusted MCS levels are MCS levels having coding rates lower than those of each of the MCS levels corresponding to a channel state of each of the specific subscriber stations. Way. An apparatus for receiving common control information transmitted from the base station to the plurality of subscriber stations in a wireless communication system having a plurality of subscriber stations in a base station area, Demultiplexing a received signal to detect the common control information including first information received by all of the plurality of subscriber stations and second information received by each of the subscriber stations according to channel conditions of the subscriber stations; With receiver, Demodulating the common control information according to a modulation scheme corresponding to a modulation and coding scheme (MCS) level applied to the first information by the base station, and corresponding to MCS levels applied to the second information. A demodulator corresponding to demodulation schemes; A decoder that decodes the demodulated common control information corresponding to a coding scheme corresponding to the MCS level applied to the first information by the base station, and correspondingly to decoding methods corresponding to the MCS levels applied to the second information. The device characterized in that it comprises a. The method of claim 20, The first information may include MCS levels applied to the second information, and location and size information of information corresponding to each of the MCS levels. The method of claim 21, The MCS level applied to the first information is characterized in that the MCS level having a minimum order modulation method and a coding method of the minimum coding rate of all MCS levels provided by the base station. The method of claim 22, The MCS levels applied to the second information are MCS levels adjusted by a predetermined level than MCS levels corresponding to channel states of each of the subscriber stations. The method of claim 22, The MCS levels applied to the second information are MCS levels corresponding to channel states of each of the subscriber stations. The method of claim 21, The MCS level applied to the first information is characterized in that the MCS level corresponding to the channel state of the subscriber station having the worst channel state of the plurality of subscriber stations. The method of claim 25, The MCS levels applied to the second information are MCS levels adjusted by a predetermined level than MCS levels corresponding to channel states of each of the subscriber stations. The method of claim 25, The MCS levels applied to the second information are MCS levels corresponding to channel states of each of the subscriber stations. The method of claim 22, MCS levels adjusted by a predetermined level than MCS levels corresponding to the channel state of each of the subscriber stations are of a lower order modulation scheme than the modulation schemes of each of the MCS levels corresponding to the channel state of each of the subscriber stations. And the coding schemes of each of the set level adjusted MCS levels are MCS levels having coding rates lower than those of each of the MCS levels corresponding to a channel state of each of the specific subscriber stations. Device. delete delete delete delete delete delete delete delete A method of transmitting common control information from the base station to the plurality of subscriber stations in a wireless communication system having a plurality of subscriber stations in a base station area, the method comprising: Classifying the plurality of subscriber stations into a plurality of groups according to their channel conditions; Generating first common control information transmitted to all of the plurality of subscriber stations; Generating second common control information transmitted to each of the plurality of groups, The first common control information is located before other information, and a coding rate applied to the first common control information is lower than a coding rate applied to the other information, and the modulation scheme applied to the first common control information. The order is lower than the order of the modulation scheme applied to the other information, and the order and coding rate of the modulation scheme applied to each of the second common control information is different. The method of claim 37, Wherein the second common control information includes information indicating a location of a corresponding group and information indicating a modulation and coding scheme level.

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