KR20060038305A - Apparatus and method for transmitting/receiving an uplink/downlink channel information in a broadband wireless access communication system - Google Patents

Abstract

In a broadband wireless access communication system having a base station and a plurality of subscriber stations present in a service area serviced by the base station, the base station transmits channel information to the subscriber stations. Generating K first TLV-encoded channel information by encoding a plurality of pieces of channel information using a preset type, length, and value (TLV) encoding method, and encoding the K first TLVs. After generating the channel information, the type information indicating that the corresponding TLV encoding channel information is the second TLV encoding channel information generated by encoding the preset second type TLV encoding scheme, and the K pieces of information in the second TLV encoding channel information. Length information indicating the length of the channel information and each of the K channel information in the second TLV encoded channel information And that the process, the first channel 2 TLV encoded information to generate the second channel 2 TLV encoded information including the K Value information, characterized in that it comprises the step of transmitting to the subscriber terminal.

TLV encoding, single TLV encoding, uplink channel information, downlink channel information, flag bitmap with TLV index, flag bitmap size with TLV index

Description

Apparatus and method for transmitting / receiving uplink / downlink channel information in a broadband wireless access communication system TECHNICAL FIELD             

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

2 is a diagram schematically showing a frame structure of a general IEEE 802.16d communication system

3 is a diagram schematically illustrating channel information transmission and reception in an IEEE 802.16e communication system according to a first embodiment of the present invention.

4 is a diagram schematically illustrating channel information transmission and reception in an IEEE 802.16e communication system according to a second embodiment of the present invention.

The present invention relates to a broadband wireless access (BWA) communication system, and more particularly, to an apparatus and a method for transmitting and receiving uplink and downlink channel information.

In the 4th generation (4G), a next generation communication system (hereinafter, referred to as '4G') communication system, it has various quality of service (QoS: quality of service, hereinafter referred to as 'QoS') with a high transmission speed. Active research is being conducted to provide services to users.

Meanwhile, a wireless local area network (LAN) communication system and a wireless metropolitan area network (MAN) communication system are generally used. However, the wireless MAN communication system is suitable for supporting high speed communication service because of its wide coverage and high speed transmission rate. (SS: Subscriber Station, hereinafter referred to as 'SS') because the system does not consider the mobility of the handover (handover) due to the high-speed movement of the SS is also not considered significantly.

Therefore, in the current 4G communication system, a new communication system is developed in a form of guaranteeing mobility and QoS in a wireless LAN communication system and a wireless MAN communication system which guarantee a relatively high transmission speed, and provide a high speed to be provided in the 4G communication system. Research to support the service is actively being conducted.

Orthogonal Frequency Division Multiplexing (OFDM) and Orthogonal Frequency Division Multiplexing (OFDM) for supporting a broadband transmission network on a physical channel of the wireless MAN communication system A system employing an access (OFDMA: Orthogonal Frequency Division Multiple Access (OFDMA)) scheme is an Institute of Electrical and Electronics Engineers (IEEE) 802.16 communication system. Since the IEEE 802.16 communication system applies OFDM / OFDMA scheme to the wireless MAN system, high-speed data transmission is possible by transmitting a physical channel signal using a plurality of sub-carriers, and thus, the IEEE 802.16 communication system Is a broadband wireless access communication system using the OFDM / OFDMA scheme.

In particular, the IEEE 802.16a communication system is a system capable of high-speed data transmission by transmitting a physical channel signal using a plurality of subcarriers because the OFDM / OFDMA scheme is applied to the wireless MAN communication system. A communication system for providing a wireless broadband Internet service to the SS. The IEEE 802.16a communication system and the IEEE 802.16d communication system currently consider only a fixed cell state, that is, a state in which the mobility of the SS is not considered at all and a single cell structure. In contrast, the IEEE 802.16e communication system is defined as a system considering SS mobility in the IEEE 802.16a communication system and the IEEE 802.16d communication system. Thus, the IEEE 802.16e system is an SS in a multi-cell environment. Consideration should be given to mobility. In order to provide SS mobility in a multi-cell environment, a change in the operation of the SS and the base station (BS) is essential. Therefore, in order to support mobility of the SS, the SS handover considering the multi-cell structure is required. The research is being actively conducted. Here, the SS having the mobility will be referred to as a mobile SS (MSS: Mobile Subscriber Station, hereinafter referred to as 'MSS'). That is, the IEEE 802.16e system has almost the same structure as the IEEE 802.16a communication system and the IEEE 802.16d communication system, but differs only in the structure of mobility support such as handover due to the movement of MSS.

Next, the structure of the IEEE 802.16e communication system will be described with reference to FIG. 1.

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

Referring to FIG. 1, the IEEE 802.16e communication system has a multi-cell structure, that is, a cell 100 and a cell 150, and the base station 110 managing the cell 100 and the cell ( The base station 140 manages 150 and a plurality of MSSs 111, 113, 130, 151, and 153. In addition, signal transmission and reception between the base stations 110 and 140 and the MSSs 111, 113, 130, 151, and 153 is performed using the OFDM / OFDMA scheme. However, among the MSSs 111, 113, 130, 151, and 153, the MSS 130 is located in a boundary area of the cell 100 and the cell 150, that is, in a handover area. It is present, and therefore, it is possible to support mobility for the MSS 130 only by supporting handover for the MSS 130.

Meanwhile, the IEEE 802.16 communication system is a communication system using a time division duplexing (TDD) method, and with reference to FIG. 2, the IEEE 802.16 communication system. As an example, a frame structure of the IEEE 802.16d communication system will be described.

2 is a diagram schematically illustrating a frame structure of a general IEEE 802.16d communication system.

Referring to FIG. 2, the horizontal axis 245 represents an OFDMA symbol number, and the vertical axis 247 represents a sub-channel number. As shown in FIG. 2, one OFDMA frame includes a plurality of OFDMA symbols, for example, 12 OFDMA symbols. In addition, the one OFDMA symbol is composed of a plurality, for example, L subchannels. The IEEE 802.16d communication system is a communication system which aims to obtain frequency diversity gain by distributing all subcarriers, in particular, data subcarriers used in the IEEE 802.16d communication system, in all frequency bands. to be.

In addition, the IEEE 802.16d communication system performs a ranging operation to adjust a time offset and a frequency offset in a transmission and reception period, and to adjust a transmit power. In the IEEE 802.16d communication system, the downlink to uplink conversion is performed during a transmit / receive transition gap (TTG) (251). In addition, the uplink to downlink conversion process is also performed during the uplink to downlink conversion (Receive / transmit transition gap (RTG)). . Meanwhile, after the TTG 251 and the RTG 255, separate preamble areas 211, 231, 233, and 235 are allocated to obtain synchronization in a transmission / reception period.

In the frame structure of the IEEE 802.16d communication system, the downlink frame 249 includes a preamble area 211, a downlink frame prefix area 213, and a downlink MAP (DL-MAP). -MAP ') region 215, uplink MAP (UL-MAP, hereinafter referred to as' UL-MAP') region 217, downlink channel descriptor (DCD: Downlink Channel Descriptor, Region 218, an uplink channel descriptor (UCD) region 219, and a plurality of downlink bursts (DL bursts). (Hereinafter, referred to as 'DL burst') regions, that is, DL burst # 1 region 223, DL burst # 2 region 225, DL burst # 3 region 221, and DL burst # 4 region ( 227 and a DL burst # 5 area 229.

The preamble area 211 is an area for transmitting a synchronization signal for synchronizing transmission and reception, that is, a preamble sequence. In addition, the downlink frame prefix region 213 carries basic information on subchannels, ranging, modulation schemes, and the like. The DL_MAP area 215 is an area where the DL_MAP message is transmitted, the UL_MAP area 217 is an area where the UL_MAP message is transmitted, the DCD area 218 is an area where the DCD message is transmitted, and the UCD area 119 is a UCD. The area where messages are sent. Information elements included in the DCD message (IE) (hereinafter, referred to as 'IE') are shown in Table 1 below.                         

As shown in Table 1, the DCD message includes a plurality of IEs, that is, a management message type indicating a type of a transmitted message, a downlink channel ID indicating a downlink channel ID used, and a downlink. A configuration change count indicating a count corresponding to a configuration change of channel information, and channel TLV encoding information indicating TLV (Type, Length, Value) encoding information for downlink channels, that is, TLV encoded information for the overall channel and PHY ( PHYsical) specification.

Herein, the size of the PHY specification part has a size as shown in Equation 1 below.

On the other hand, the parameters constituting the TLV Encoded information for the overall channel are set differently according to a physical interface (PHY Scope) between the base station and the SS. That is, the TLV Encoded information for each channel depends on whether the physical interface between the base station and the SS is a single carrier (SC) system, a single carrier (SCa) system, an OFDM system, or an OFDMA system. The parameters constituting the overall channel will be different. Since the operation of generating the types of parameters constituting the TLV Encoded information for the overall channel and the parameters constituting the TLV Encoded information for the overall channel are not directly related, detailed description thereof will be omitted herein.

Here, the parameters constituting the TLV encoded information for the overall channel when the physical interface between the base station and the SS is the SC scheme are shown in Table 2 below.

In addition, the parameters configuring the TLV Encoded information for the overall channel when the physical interface between the base station and the SS is the OFDMA scheme are shown in Tables 3a and 3b.

As shown in Table 2 and Tables 3a and 3b, the TLV Encoded information for the overall channel has a TLV encoding form in which a type and a length are inserted in a substantial value, thereby causing a base station. And may be selectively included in the DCD message and transmitted according to a physical interface used in the SS or according to parameters required by one physical interface.

Next, the format of the downlink burst profile will be described with reference to Table 4.                         

As shown in Table 4, the downlink burst profile includes a Type indicating a type, a Length indicating a length of the downlink burst profile, a reserved reserved reserved for future use, and a downlink burst currently transmitted. Downlink Interval Usage Code (DIUC), which indicates which profile is modulated and transmitted in what manner, and TLV encoding information. The downlink burst profile as described in Table 4 is included in the PHY specification of the DCD message by the number of the downlink burst profiles.

The parameters constituting the TLV encoding information of the downlink burst profile are configured differently according to the physical interface between the base station and the SS as described above. That is, as described above, the parameters constituting the TLV encoding information of the downlink burst profile differ depending on whether the physical interface between the base station and the SS is SC, SCa, OFDM, or OFDMA. It is done. Since the type of parameters constituting the TLV encoding information of the downlink burst profile and the generation of the parameters constituting the TLV encoding information of the downlink burst profile are not directly related, a detailed description thereof will be omitted.

Here, the parameters constituting the TLV encoding information of the downlink burst profile when the physical interface between the base station and the SS is the SC scheme are as shown in Tables 5a and 5b.                         

In addition, the parameters constituting the TLV encoding information of the downlink burst profile when the physical interface between the base station and the SS is the OFDMA scheme are shown in Table 6 below.                         

As shown in Tables 5a, 5b, and 6, the TLV encoding information of the downlink burst profile has a TLV encoding form in which a type and a length are inserted into a substantial value. Depending on the physical interface used in the base station and SS, or according to the parameters required in one physical interface may be selectively included in the DCD message and transmitted.

Meanwhile, IEs included in the UCD message are as shown in Table 7 below.

As shown in Table 7, the UCD message includes a management message type indicating a plurality of IEs, that is, a type of a message to be transmitted, a configuration change count counted by a base station, and a backoff using initial ranging. Ranging Backoff Start, which indicates the starting point of the backoff, that is, the size of the initial backoff window using initial ranging, and end point of the backoff using the initial ranging, that is, the final backoff window. backoff window) Ranging Backoff End, which indicates the size, Request Backoff Start, which indicates the start of the backoff for contention data and requests; I.e., the Request Backoff End, which indicates the final backoff window size, and a channel that consists of the TLV encoding parameters. Coding information (TLV Encoded information for the overall channel) and a PHY name detail. Here, the size of the PHY specification unit of the UCD message has the size of the following equation (2).

Meanwhile, the channel encoding information of the UCD message, that is, the parameters constituting the TLV Encoded information for the overall channel, are also set differently according to the physical interface between the base station and the SS. That is, the parameters constituting the TLV Encoded information for the overall channel for each channel are different depending on whether the physical interface between the base station and the SS is SC, SCa, OFDM, or OFDMA. . Since the operation of generating the types of parameters constituting the TLV Encoded information for the overall channel and the parameters constituting the TLV Encoded information for the overall channel are not directly related, detailed description thereof will be omitted herein.

Next, the format of the uplink burst profile will be described with reference to Table 8 below.

As shown in Table 8, the uplink burst profile includes a Type indicating a type, a Length indicating a length of the uplink burst profile, a reserved reserved reserved for future use, and an uplink usage interval code. Uplink interval usage code (UIUC: [(] Uplink Interval Usage Code [;], hereinafter referred to as 'UIUC') and TLV encoding information are included.) Uplink burst profile as described in Table 8 above. The number of the uplink burst profiles is included in the PHY specification of the UCD message.

The parameters constituting the TLV encoding information of the uplink burst profile are configured differently according to the physical interface between the base station and the SS as described above. That is, as described above, the parameters constituting the TLV encoding information of the uplink burst profile differ according to whether the physical interface between the base station and the SS is SC, SCa, OFDM, or OFDMA. It is done. Since the operation of generating the parameters constituting the TLV encoding information of the uplink burst profile and the parameters constituting the TLV encoding information of the uplink burst profile is not directly related, a detailed description thereof will be omitted.

Meanwhile, in the frame structure of the IEEE 802.16d communication system of FIG. 2, an uplink frame 253 includes a ranging subchannel region 243, a plurality of preamble regions 231, 233, and 235, and a plurality of uplink bursts ( UL burst, hereinafter referred to as 'UL burst') regions, that is, the UL burst # 1 region 237, the UL burst # 2 region 239, and the UL burst # 3 region 241. The ranging subchannel region 243 is a region in which ranging subchannels for ranging are transmitted, and the preamble regions 231, 233, and 235 are regions in which a synchronization signal for synchronizing transmission / reception periods, ie, a preamble sequence, is transmitted.

As described above, in the IEEE 802.16d communication system, a base station must inform all MSSs in a service area served by the base station itself of channel information allocated in a downlink frame and an uplink frame. And access to the uplink frame.

That is, the base station informs downlink and uplink channel information by periodically broadcasting the DCD message and the UCD message to all MSSs in the service area serviced by the base station itself, and the channel of the DCD message and the UCD message. The size of the information and burst profile increases greatly as the number of TLV encoding parameters included in the DCD message and the UCD message increases, thus reducing transmission efficiency. In the worst case, the DCD message and the UCD message cannot be delivered in one frame. It can also happen.                         

That is, as described above, in order to transmit the actual parameter from the base station to the MSS, a TLV encoding scheme using a type or length field added to each parameter is used. As an example, in order to transmit the actual value of a parameter of 1 byte, an overhead called a type field of 1 byte and a length field of 1 byte must be attached to all parameters. This provides an advantage of flexibility in selectively including the parameters to be transmitted in the DCD message and the UCD message, but the length of the message is significantly longer depending on the number of parameters included due to the TLV encoding scheme. Has its drawbacks. The significant increase in the message length results in a decrease in transmission efficiency, and in the worst case, even when a message that must be broadcast periodically every one frame cannot be transmitted in one frame.

Accordingly, an object of the present invention is to provide an apparatus and method for transmitting and receiving uplink / downlink channel information in a broadband wireless access communication system.

It is another object of the present invention to provide an apparatus and method for encoding uplink / downlink channel information with minimal overhead in a broadband wireless access communication system.

The method of the present invention for achieving the above objects; In a broadband wireless access communication system having a base station and a plurality of subscriber stations present in a service area serviced by the base station, the base station transmits channel information to the subscriber stations, wherein the K channels of the base station are provided. Generating the K first TLV-encoded channel information by encoding the information by using a preset type, length, value (TLV) encoding method, and the K first TLV-encoded channel information. Type information indicating that the TLV encoding channel information is second TLV encoding channel information generated by encoding the preset second type TLV encoding scheme, and the K channel information in the second TLV encoding channel information. Length information indicating a length of a field and an image representing each of the K channel information in the second TLV encoded channel information. Characterized in that the process and, wherein the 2 TLV encoded channel information for generating the second channel 2 TLV encoded information including the K Value information comprising the step of transmitting to the subscriber terminal.

Another method of the present invention for achieving the above objects is; In a broadband wireless access communication system having a base station and a plurality of subscriber stations present in a service area serviced by the base station, the base station transmits channel information to the subscriber stations, wherein the K channel information of the base station is provided. Generating the K first TLV encoded channel information by encoding the first TLV encoding channel information by using a preset type, length, value (TLV) encoding scheme, and generating the K first TLV encoded channel information. After generating, the type information indicating that the TLV encoding channel information is second TLV encoding channel information generated by encoding the preset second type TLV encoding scheme, and the K channel information in the second TLV encoding channel information. Length information indicating the length of the selected M channel information, and the M channels in the second TLV encoded channel information. Generating the second TLV encoded channel information including the M value information representing each piece of information; and transmitting the second TLV encoded channel information to the subscriber stations.

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.

The present invention proposes a method for transmitting and receiving downlink and uplink channel information in an Institute of Electrical and Electronics Engineers (IEEE) 802.16e communication system, which is a broadband wireless access (BWA) communication system. . In particular, the present invention proposes a method of transmitting and receiving the downlink and uplink channel information by using a channel encoding scheme capable of minimizing the overhead of transmitting and receiving downlink and uplink channel information in an IEEE 802.16e communication system. do. The IEEE 802.16e communication system has a broadband over a physical channel of a Metropolitan Area Network (MAN) communication system as described in the prior art section of the present invention. Orthogonal Frequency Division Multiplexing (OFDM) and Orthogonal Frequency Division Multiple Access (OFDMA) to support transport networks In the present invention, the IEEE 802.16de communication system is described as an example for convenience of description, but the downlink and uplink channel information transmission / reception scheme proposed by the present invention is not the IEEE 802.16e communication system. Of course, it can be used in other broadband wireless access communication systems.

<First Embodiment of the Present Invention>

In the first embodiment of the present invention, downlink channel information and uplink channel information as described in Tables 1 to 8 of the prior art portion of the present invention, that is, a downlink channel descriptor (DCD) is hereinafter referred to as 'DCD'. Downlink channel information and uplink channel information such as uplink channel descriptor (UCD) message and uplink channel information (UCD) message, and the like (TLV: Type). Instead of encoding in an encoding scheme (hereinafter, referred to as an existing TLV encoding scheme), a method of encoding and transmitting in a single encoding TLV scheme is proposed. Here, the downlink channel information refers to all information related to a downlink channel in the IEEE 802.16e communication system, and the uplink channel information refers to all information related to an uplink channel in the IEEE 802.16e communication system. Indicates.

Next, a channel information transmission / reception scheme according to the first embodiment of the present invention will be described with reference to FIG. 3.

3 is a diagram schematically illustrating channel information transmission and reception in the IEEE 802.16e communication system according to the first embodiment of the present invention.

Before describing FIG. 3, a base station (BS) of the IEEE 802.16e communication system is used to perform downlink and uplink channel information transmission and reception according to a single TLV encoding scheme according to the first embodiment of the present invention. And a mobile subscriber station (hereinafter referred to as MSS) must satisfy three conditions of the following first to third conditions.

<First condition>

When the base station and the MSS encode downlink channel information and uplink channel information using the existing TLV encoding scheme instead of the single TLV encoding scheme, the channel information encoded by the existing TLV encoding scheme (hereinafter, referred to as 'previous TLV encoded channel information'). TLV indices assigned to the C) must be mutually defined in advance. That is, TLV index mapping relations sequentially allocated from 1 to n in a predetermined order regardless of the type of the existing TLV encoding scheme that differ according to the physical interface (PHY Scope) scheme between the base station and the SS The base station and the MSS must be in agreement with each other in advance. Here, the physical interface scheme between the base station and the MSS includes a single carrier (SC) scheme, a single carrier a (SCa) scheme, an OFDM scheme, and an OFDMA scheme. For example, as described in Tables 3a and 3b of the prior art portion of the present invention, when the physical interface scheme between the base station and the MSS is the OFDMA scheme, the downlink channel information and uplink channel information are encoded by the existing TLV encoding scheme. The TLV index is mapped to existing TLV-encoded channel information as shown in Table 9 below.

<Second condition>

The DCD message and the UCD message transmitted and received between the base station and the MSS must include all channel information encoded in the existing TLV encoding scheme, that is, all existing TLV encoded channel information. That is, in the first embodiment of the present invention, even if the single TLV encoded channel information is actually used, at least the DCD message and the UCD message must include the existing TLV encoded channel information.

<Third condition>

Value information in the single TLV-encoded channel information included in the DCD message and the UCD message transmitted and received between the base station and the MSS must be known in advance. That is, when using the existing TLV encoding scheme, it is possible to detect the length of the Value information in the existing TLV encoded channel information by using Length information of the existing TLV encoded channel information transmitted by the base station, but according to the first embodiment of the present invention In the above, the length of the value information in each existing TLV encoding channel information corresponding to the TLV index must be previously regulated between the base station and the MSS.

Referring to FIG. 3, a base station broadcasts the DCD message to all MSSs within a service area served by the base station itself to recognize downlink channel information. Conventionally, the downlink channel information is encoded by the existing TLV encoding. In the first embodiment of the present invention, single TLV-encoded channel information is generated by detecting only Value, which is actual downlink channel information. Here, the Type 313 of the single TLV-encoded channel information is allocated to a new value which is not currently used in the corresponding TLV-encoded channel information group, and Length is the length of the actual channel information Value of the single TLV-encoded channel information. Indicates.

As described in the first embodiment of the present invention, by using the single TLV encoding scheme, type information and length information included in each of the plurality of pieces of existing TLV encoding channel information 309 encoded by the existing TLV encoding scheme are deleted. It is possible to minimize the length of the DCD message itself as a result, which may result in a gain in transmission efficiency. As such, the single TLV encoding channel information generated by encoding the single TLV encoding scheme includes a Type 313, a Length 315, and a plurality of Values 317.

When encoding downlink channel information and uplink channel information using the single TLV encoding method, the UCD message and the DCD message format currently used in the IEEE 802.16e system may be used as they are. Have efficiency. However, it should be used exclusively with other TLV encodings of the corresponding TLV encoding group.

Downlink burst profiles (305,306) in the DCD message may also be generated as single TLV encoded channel information using the single TLV encoding scheme, and the single TLV encoded channel information may also be Type 319 and Length (321). ) And a plurality of values 323.

Meanwhile, when the base station transmits single TLV encoded channel information generated by using the single TLV encoding scheme according to the first embodiment of the present invention to the MSSs, the MSSs receive Type information indicating the single TLV encoded channel information. When receiving a single TLV-encoded channel information, the branch must be interpreted by dividing by the length of the single TLV-encoded channel information previously prescribed with the base station. Then, the MSSs can normally detect values that are actual channel information in the single TLV encoded channel information.

<Second embodiment of the present invention>

The second embodiment of the present invention uses an encoding scheme in which the single TLV encoding scheme described in the first embodiment of the present invention is modified. That is, although the first embodiment of the present invention generates single TLV encoded channel information in consideration of all existing TLV encoded channel information, in the second embodiment of the present invention, all existing TLV encoded channel information are selected according to the situation. Generate TLV encoded channel information into single TLV encoded channel information. In this case, since it is necessary to know the selected existing TLV encoding channel information, the following parameters to distinguish the selected and included existing TLV encoding channel information, that is, a flag bitmap including a TLV index (Inclusion flag-bitmap) for TLV Index and Size of Inclusion flag-bitmap for TLV Index should be included in Value information of the single TLV encoded channel information. Here, the TLV index-containing flag bitmap will be described below.

First, each bit is mapped to a corresponding TLV index, and only if the bit value is '1', actual channel information of existing TLV encoding channel information indicated by the corresponding TLV index, that is, Value information is encoded in the single TLV index. It is included in the value information of the channel information. Most Significant Bits (MSBs) of the flag bitmap including the TLV index are mapped from the TLV index.

Next, the TLV index-containing flag bitmap size will be described.

The TLV index-containing flag bitmap size indicates the size of the TLV index-containing flag bitmap and may be expressed in byte units. Of course, the TLV index-containing flag bitmap size may be expressed in units of bits, for example, and for convenience of description, the byte unit is used in the second embodiment of the present invention.

Next, a channel information transmission / reception scheme according to the second embodiment of the present invention will be described with reference to FIG. 4.

4 is a diagram schematically illustrating channel information transmission and reception in an IEEE 802.16e communication system according to a second embodiment of the present invention.

Referring to FIG. 4, a base station broadcasts the DCD message to all MSSs within a service area served by the base station itself to recognize downlink channel information. Conventionally, the downlink channel information is encoded by the existing TLV encoding. In the first embodiment of the present invention, only the value of the actual downlink channel information is detected, and only the selected downlink channel information value is detected. Generates single TLV encoded channel information.

In the second embodiment of the present invention, single DCV encoded channel information is generated by sequentially mapping only actual channel information of selected existing TLV encoded channel information among all existing TLV encoded channel information to Value information in the DCD message and the UCD message. (411, 413, 415). The Value information 415 to distinguish Value information 421 included in Value information 415 which is actual channel information included in the single TLV encoded channel information, that is, actual channel information of selected existing TLV encoded channel information. Includes the TLV index-containing flag bitmap 419 and the TLV index-containing flag bitmap size 417 described in the second embodiment of the present invention. The TLV index containing flag bit map 419 is mapped to each of the existing TLV encoded channel information 409 selectively included in the DCD and UCD messages, that is, a bit corresponding to the TLV index as shown in Table 9 above. Is set to '1'. The existing TLV encoded channel information 409 illustrated in FIG. 4 has a, n, and x as type information, and the TLV index 423 s mapped thereto becomes 1, 2, and 8. The first bit, the second bit, and the eighth bit of the corresponding TLV index containing bitmap map 419 are set to '1' (425, 427, 429), and thus the TLV index containing flag bitmap size 419. ) Size 417 is set to 1 (unit: byte).

The type information 411 of the single TLV encoded channel information is allocated to a new value not used in the corresponding TLV encoding group, and the length information 413 is the actual channel value (Value) 415 of the single TLV encoded channel information. ) Length.                     

As described in the second embodiment of the present invention, the single TLV-encoded channel information 411, 413, and 415 may also use the UCD message and the DCD message format currently used in the IEEE 802.16e system. In terms of efficiency, However, it should be used exclusively with other TLV encodings of the corresponding TLV encoding group.

As described above, by using the single TLV encoding scheme of the second embodiment of the present invention, type information and length information used for each of the existing TLV encoding channel information 409 can be deleted, resulting in the message lengths of the DCD and UCD. Since it is possible to reduce the gain in transmission efficiency, it is also applicable to the case of TLV encoding that is optionally included. By configuring the single TLV-encoded channel information 411, 413, and 415 in this way, the single TLV-encoded channel information 411 is simply added in terms of backward compatibility of changing the message format of UCD and DCD in the IEEE 802.16e communication system. , 413, 415), so no problem at all. The base station uses existing TLV encoded channel information 409 using the conventional TLV encoding scheme as it is, or provides single TLV encoded channel information 411, 413, which is proposed in the second embodiment of the present invention for more efficient transmission. 415) can be used.

The TLV encoding 407 constituting the downlink burst profiles 405 and 406 used in the DCD message 401 may also be implemented using a single TLV encoding scheme as described in the DCD message 401. Type information and length information used for existing TLV encoding channel information generated according to an existing TLV encoding scheme can be deleted, thereby significantly reducing the length of the DCD message. The burst profile information of the UCD message can also be processed in the same manner as the burst profile information of the DCD message, and the effects are the same.

Meanwhile, when the base station encodes and transmits downlink channel information and uplink channel information by using a single TLV encoding scheme according to the second embodiment of the present invention, MSSs are single TLVs having type information indicating that they are single TLV encoded channel information. Upon receiving the encoding channel information, the corresponding TLV index containing flag bit map may be extracted using the TLV index containing flag bit map size value. Accordingly, the MSSs should interpret the actual values of several TLV encoding parameters included in a single substantial value by the length of known values.

Third Embodiment of the Present Invention

The third embodiment of the present invention is a modification of the single TLV encoding scheme of the second embodiment of the present invention, and assumes default values for all TLV encoding parameters are predefined between all base stations and all MSSs. Let's do it. Here, the default value may be determined as a value previously set in the IEEE 802.16e communication system, and may be changed to any value only if a protocol is established between all base stations and all MSSs.

In this state, in applying the second embodiment of the present invention to UCD and DCD messages broadcasted by the base station to inform downlink channel information to all MSSs in the service area to which the base station itself provides services, It is proposed to be included only if the actual value of the TLV encoding is different from the default value. For example, when a base station using OFDMA as the physical interface transmits an uplink channel information message, among the parameters constituting TLV Encoded information for the overall channel of Table 3 or Table 9, 'H-ARQ' is used. If the ACK delay for DL burst 'is used in the IEEE802.16 communication system, the default value is' 1 = 1 frame offset'. Only the value of the H-ARQ ACK delay for DL burst is included by the condition included in the.

Meanwhile, since several default values may exist, an ID for distinguishing a group of default values may be included in a substantial value of the single TLV encoding. The ID used herein may include a standard organization identifier and a default group identifier presented by the standard organization.

The third embodiment is a form in which only the above-described parameters are added, and the applied rule follows the above description and the second embodiment, and thus further description thereof will be omitted.

Substantial values of the single TLV encoding described in the first, second, and third embodiments basically consist of substantial values of several TLV encodings in byte units, but have eliminated unnecessary bits in bits to improve transmission efficiency. It may also consist of substantial values of. Of course, as a prerequisite, the fact must be known between the base station and the subscriber in advance, and it must be specified in the specification, that is, the IEEE802.16d / e specification.                     

In addition, the single TLV encoding method described in the first, second, and third embodiments of the present invention may be equally applied to TLV encodings existing in all other MAC Management messages in addition to the UCD and DCD messages. For example, it may be applied to MOB_NBR-ADV message of IEEE 802.16e communication system.

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 has the advantage of minimizing the overhead of downlink channel information and uplink channel information transmitted and received between a base station and MSS in a broadband wireless access communication system. Minimizing the overhead of the downlink channel information and uplink channel information ultimately increases the efficiency of the resource, and minimizing the overhead makes it possible to use the resource for other purposes. In addition, the downlink channel information and uplink channel information transmission and reception proposed in the present invention has the advantage that it is possible to maintain compatibility with the transmission and reception of downlink channel information and uplink channel information in a general broadband wireless access communication system.

Claims (4)

In a broadband wireless access communication system having a base station and a plurality of subscriber stations present in a service area serviced by the base station, the base station transmits channel information to the subscriber terminals. Generating the K first TLV encoded channel information by encoding the K channel information of the base station by using a preset type, length, value (TLV) encoding scheme; After generating the first K TLV encoding channel information, Type information indicating that the corresponding TLV encoding channel information is second TLV encoding channel information generated by encoding the preset second type TLV encoding scheme, and the second TLV. The second TLV encoded channel information including Length information indicating the length of the K channel information in encoding channel information, and the K value information indicating each of the K channel information in the second TLV encoded channel information. Creating process, And transmitting the second TLV encoded channel information to the subscriber stations. In a broadband wireless access communication system having a base station and a plurality of subscriber stations present in a service area serviced by the base station, the base station transmits channel information to the subscriber terminals. Generating the K first TLV encoded channel information by encoding the K channel information of the base station by using a preset type, length, value (TLV) encoding scheme; After generating the first K TLV encoding channel information, Type information indicating that the corresponding TLV encoding channel information is second TLV encoding channel information generated by encoding the preset second type TLV encoding scheme, and the second TLV. The length information indicating the length of the selected M channel information among the K channel information in the encoding channel information, and the M value information indicating each of the M channel information in the second TLV encoded channel information. Generating second TLV encoded channel information; And transmitting the second TLV encoded channel information to the subscriber stations. The method of claim 2, The second TLV encoding channel information may further include selection information indicating the selected M first TLV encoding channel information among the K first TLV encoding channel information, and size information of the selection information. Way. The method of claim 3, Wherein the selection information is indices mapped to each of the selected M first TLV encoding channel information among indices mapped one-to-one to each of the K first TLV encoding channel information.

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