KR20110041376A - Apparatus and moethod for transmitting/receiving system information in broadband wireless communication system - Google Patents

Abstract

PURPOSE: A system information transmitting/receiving apparatus and method thereof are provided to inform system information which is updated through an IE(Information Element). CONSTITUTION: A system information decider(502) sets up a configuration switching flag as a first value. The system information decider sets up the configuration transition flag as a second value. An RF transmitter(510) transmits a P-SFH(Primary-Super Frame Header) including the fixed configuration switching flag to the first value or the second value.

Description

Apparatus and method for transmitting and receiving system information in broadband wireless communication system {APPARATUS AND MOETHOD FOR TRANSMITTING / RECEIVING SYSTEM INFORMATION IN BROADBAND WIRELESS COMMUNICATION SYSTEM}

The present invention relates to a broadband wireless communication system, and more particularly, to an apparatus and method for transmitting and receiving system information in a broadband wireless communication system.

Currently, the mobile communication system has been developed in the form of providing various services such as broadcasting, multimedia video, and multimedia messages, based on the existing voice communication. These next-generation communication systems include the Institute of Electrical and Electronics Engineers (IEEE) 802.16e system, 3GPP Long Term Evolution (LTE), IEEE 802.20 Ultra Mobile Broadband (UMB), and IEEE 802.16m system. .

In order to support a high data rate in the mobile communication system, various transmission schemes such as a multiple antenna system, a hybrid auto repeat request (HARQ), and an adaptive modulation and coding (AMC) are introduced. In order for these transmission schemes to operate, the base station must transmit a lot of system information to multiple user terminals. The system information includes network and cell common information that a user terminal needs to know in order to perform mobile communication in a cell, for example, cell bandwidth information, physical channel configuration information, and higher layers. Information such as a parameter of a layer, information of various transmission schemes supported by a cell, for example, the number of transmit antennas, information of multiple antennas, HARQ-related information, modulation scheme information, and the like.

According to the Institute of Electrical and Electronics Engineers (IEEE) 802.16m, one of the wireless communication standards, system information is transmitted in the form of a primary-super frame header (P-SFH) and a secondary-super frame header (S-SFH). . The S-SFH is divided into SP1 (SubPacket1), SP2, and SP3, and the transmission periods of the SP1, the SP2, and the SP3 may be different from each other. The P-SFH includes information indicating whether the S-SFH is transmitted in the same frame, which SP is transmitted, and how large is the size. In addition, the P-SFH indicates a change in system information by using an S-SFH change count and an S-SFH SP change bitmap, and an S-SFH scheduling information bitmap. Use to inform what the SP is transmitted in the same frame.

 The S-SFH change count is mapped with the transmitted SPs. For example, if the S-SFH change count is N, SP1, SP2 and SP3 transmitted include system parameters of 'S-SFH Change Count = N' status. Therefore, the change count is changed, at least one of the SPs of the S-SFH has been updated. The S-SFH SP change bitmap indicates which SP has changed. In addition, each SPx includes a 2-bit offset parameter indicating a superframe offset at which the use of the changed SP starts, and the offset parameter indicates when the changed new configuration is applied. Therefore, after receiving the new SPx, the terminal applies new parameters in the super frame indicated by the offset parameter in the SPx.

The change count and change bitmap included in the P-SFH indicate that the system information has been updated and which SP has been updated. However, even if the UE recognizes the updated SP and the updated SP by receiving the P-SFH, when the terminal does not receive the updated SPx due to an operation state such as channel degradation or sleep mode, the updated SPx is updated. It is impossible to know when SPx is applied and communication should be stopped. Accordingly, the terminal cannot perform communication until the corresponding SPx is successfully decoded. Therefore, even if the updated SPx is not received, an alternative for enabling the terminal to perform communication before the application of the updated system information by recognizing the application time of the updated SPx is needed.

Accordingly, an object of the present invention is to provide an apparatus and method for notifying the application time of updated system information in a broadband wireless communication system.

Another object of the present invention is to provide an apparatus and method for notifying application time of updated system information through an information element (IE) transmitted in every super frame in a broadband wireless communication system.

Another object of the present invention is to provide an apparatus and method for updating SPs (SubPackets) of a plurality of system information at the same time in a broadband wireless communication system.

According to the first aspect of the present invention for achieving the above object, the operation method of the base station in a broadband wireless communication system, the system configuration corresponding to the previous value of the change count (change count) changed in accordance with the update of the system information is applied. Determining whether or not to perform the operation, when applying a system configuration corresponding to the previous value of the change count, setting a configuration transition flag to a first value, and corresponding to the current value of the change count. In the case of applying a system configuration to be applied, the P-SFH (Primary-Super) includes setting the configuration switching flag to a second value, and including the change count and the configuration switching flag set to the first value or the second value. Frame header).

According to a second aspect of the present invention for achieving the above object, a method of operating a terminal in a broadband wireless communication system is to update the system information and the value of the configuration switching flag included in the P-SFH received through the super frame header. Checking a value of the change count changed according to the change, if the value of the configuration change flag is a first value, performing communication by applying a system configuration corresponding to a previous value of the change count, and performing the configuration change flag If the value is a second value, the step of performing a communication by applying a system configuration corresponding to the current value of the change count.

According to a third aspect of the present invention for achieving the above object, in a broadband wireless communication system, after determining whether to apply a system configuration corresponding to a previous value of a change count changed according to updating of system information, When a system configuration corresponding to a previous value of the change count is applied, a configuration switch flag is set to a first value, and when a system configuration corresponding to the current value of the change count is applied, the configuration switch flag is set as a second value. And a transmitter for transmitting the P-SFH including the change count and the configuration change flag set to the first value or the second value.

According to a fourth aspect of the present invention for achieving the above object, in a broadband wireless communication system, a terminal device is changed according to an update of system configuration information and system information included in a P-SFH received through a super frame header. And a manager for confirming a value of the change count, which is configured to perform communication by applying a system configuration corresponding to a previous value of the change count when the value of the configuration change flag is the first value, and the value of the configuration change flag is set to zero. And a controller configured to perform communication by applying a system configuration corresponding to the current value of the change count when the value is 2.

By notifying the terminal of the application time of the updated system information in the broadband wireless communication system, it is possible to minimize the inoperable state due to the non-receipt of the system information.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

Hereinafter, a description will be given of a technique for notifying application time of updated system information in a broadband wireless communication system. Hereinafter, the present invention will be described using an Orthogonal Frequency Division Multiplexing (OFDM) / Orthogonal Frequency Division Multiple Access (OFDMA) scheme as an example. The same applies to other wireless communication systems.

1 illustrates an example of a frame structure in a broadband wireless communication system according to the present invention.

Referring to FIG. 1, the super frame 100 is divided into a plurality of frames 110, and the frame 110 is divided into subframes 120 composed of a plurality of OFDM symbols 130. Within the super frame 100, the first subframe of the first frame includes a super-frame header 140, and the super frame header 140 includes a synchronization channel and a common control channel. Include. The super frame header 140 is an area for transmitting the system information necessary for the terminal to communicate with the corresponding base station. The system information is divided into Primary-Super Frame Header (P-SFH) and Secondary-Super Frame Header (S-SFH), and the S-SFH is divided into SubPacke (SP) 1, SP2, and SP3. For convenience of the following description, the present invention collectively referred to as SPx, SP2 and SP3.

The P-SFH is always included in the super frame header 140, and the SPx is optionally included. For example, each SPx is transmitted according to its period. When the SPx is included, the SPx is mapped to a resource located consecutively to the resource occupied by the P-SFH. Accordingly, the terminal may extract the SPx in the frame by using the size information of the SPx included in the P-SFH. The P-SFH and each SPx are distinguished according to the types of parameters included, and the configuration of specific parameters of each Information Element (IE) may vary according to the intention of the inventor of the present invention. For example, the parameters included in the P-SFH and each SPx are shown in Tables 1 to 4 below. Table 1 shows the parameters included in the P-SFH, Table 2 shows the parameters included in the SP1, Table 3 shows the parameters included in the SP2, Table 4 Examples of the parameters included in the SP3 are shown.

parameter Explanation LSB of Superframe
number Part of superframe number S-SFH change count Describes the S-SFH SPx IE that apply to this superframe. S-SFH Size The units of LRU S-SFH Transmission
Format Indicate the transmission format (repetition) used for S-SFH S-SFH Scheduling
information bitmap 0b000: no S-SFH
If 1stbit = 1, S-SFH includes SP1 otherwise no SP1
If 2ndbit = 1, S-SFH includes SP2 otherwise no SP2
If 3rdbit = 1, S-SFH includes SP3 otherwise no SP3
Indicate the change of S-SFH SPxIE. The bit # 0 to bit # 2 is
mapped to S-SFH SP1 IE to S-SFH SP3 IE, respectively. S-SFH SP change bitmap Indicate which SPx is IE is updated.

parameter Explanation MSB of superframe number Remaining bit of SFN except LSB of SFN in P-SFH LSB of ABS ID Specifies the 24 least bit of ABS ID Periodicity of A-MAP 0b0: every subframe
0b1: every 2 subframes A-MAP transmission format 0b0: 1/2 or 1/4 code rate for assignment A-MAP
0b1: 1/2 or 1/8 code rate for assignment A-MAP DL permutation configuration
(CRU, DRU partitioning and
signaling related to that) DL_CAS_SB0 (4), DL_CAS_MB0 (6), DL CAS_SBi (4x3) (Up to 22bits, Need the decision from DL physical structure section) UL permutation configuration
(CRU, DRU partitioning and
signaling related to that) UL_CAS_SB0 (4), UL_CAS_MB0 (6), UL CAS_SBi (4x3) (Up to 22bits, Need the decision from DL physical structure section) Initial ranging channel
information (initial ranging
region location) (Need the decision from UL Ctrl section) RNG codes information Parameters for determining the root sequences and their cyclic shifts in the preamble set for the cell (Up to 12 bits, Need the decision from UL Ctrl section) HO ranging codes 64 RNG codes (Need the decision form UL Ctrl section) HO Ranging backoff start Initial backoff window size for HO ranging contention,
expressed as a power of 2. Values of n range 0-15 (the highest order bits shall be unused and set to 0) (Need the decision from UL Ctrl or MAC operation section) HO Ranging backoff end Final backoff window size for HO ranging contention, expressed as a power of 2. Values of n range 0-15 (the highest order bits shall be unused and set to 0) (Need the decision from UL Ctrl or MAC operation section) ABS EIRP Signed in units of 1 dBm Cell bar information If Cell Bar bit = 1, this cell is not allowed for any initial entry

parameter Explanation Duplexing mode Sub-frame configuration
(DL / UL ratio, duplexing mode) If (Duplexing mode == FDD) {
UL carrier frequency
UL bandwidth
} MSB bytes of BSID Specifies the Operator ID FFR partitioning info for DL
region DL_SAC (4), DL_FPSC (3), DL_FPC (4) (Up to 11 bits, Need the decision from DL Physical structure section) FFR partitioning info
for UL region UL_SAC (4), UL_FPSC (3), UL_FPC (4) (Up to 11 bits, Need the decision from UL Physical structure section) Initial ranging codes 64RNG codes (Need the decision from UL Ctrl section) Initial ranging
backoff start Initial backoff window size for initial ranging contention, expressed as a power of 2. Values of n range 0-15 (Need the decision from UL Ctrl or MAC operation section) Bandwidth request backoff start Initial backoff window size for contention BRs, expressed as a power of 2. Values of n range 0-15 (the highest order bits shall be unused and set to 0) (Need the decision from UL Ctrl or MAC operation section) Bandwidth request
backoff end Final backoff window size for contention BRs, expressed as a power of 2. Values of n range) -15 (Need the decision from UL Ctrl or MAC operation section) NSP ID Network service provider ID Additional broadcast
information indicator (ABI) AMS Transmit Power Limitation
Level Unsigned 8-bit integer. Specifies the maximum allowed AMS transmit power. Values indicate power levels in 1 dB steps starting from 0 dBm Minimum level of power offset adjustment Maximum level of power offset adjustment

parameter Explanation Rate of change of SP (1-3) info SA-sequence soft partitioning
information FFR partition resource metrics MIMO rank 1 OL region signaling MIMO rank 1 OL region NI information
for UL power control Periodic ranging channel
information (periodic ranging
region location) Need the decision from UL Ctrl section Periodic ranging codes 64RNG codes
(Need the decision from UL Ctrl section) Periodic ranging backoff start Initial backoff window size for periodic ranging contention, expressed as a power of 2. Values of n range 0-15 (Need the decision from UL Ctrl or MAC operation section) Periodic ranging backoff end Final backoff window size for periodic ranging contention, expressed as a power of 2. Values of n range 0-15 (Need the decision from UL Ctrl or MAC operation section) UL FB Size Specifies the size of UL feedback channel per a UL subframe (Need the decision from UL Ctrl section) #Tx antenna 0b00: 2 antennas
0b01: 4 antennas
0b10: 8 antennas
0b11: reserved Default RSSI and CINR
averaging paramter Bits 0-3: Default averaging paramter αavg for physical CINR measurements, in multiple of 1/16
Bits 4-7: Default averaging paramter αavg for RSSI
measurements, in multiple of 1/16 Tx Power report SP scheduling periodicity
information

A base station according to an embodiment of the present invention includes a configuration transition flag (CTF) in the P-SFH. The configuration change flag is a parameter indicating whether to apply a system configuration corresponding to a current value of an S-SFH change count, and is defined as shown in Table 5 below.

Syntax Size
(bit) Notes Configuration Transition Flag One 0: Apply system configuration corresponding to the current value of the change count
1: Apply the system configuration corresponding to the previous value of the change count

When the current value of the change count is 'N' and the configuration change flag is '0', the terminal applies a system configuration corresponding to the change count 'N', that is, a system configuration according to the system information currently being transmitted. . On the other hand, if the current value of the change count is 'N' and the configuration change flag is '1', the terminal is the system information corresponding to the change count 'N-1', that is, the change count is 'N-1'. Apply the system configuration according to the system information that was sent.

As the P-SFH includes the configuration change flag, transmission and reception of system information is performed as follows.

2A to 2C illustrate a transmission time of system information in a broadband wireless communication system according to an exemplary embodiment of the present invention.

2A shows the case where the updated SPx is transmitted with the increase of the change counter. Referring to FIG. 2A, in the interval 1211, the change count is 'N', and the change bitmap is '0b000'. At this time, since the configuration change flag is '0', the system configuration according to the SPx corresponding to the current value of the change count is applied. Therefore, a new terminal entering the base station (entry) receives the currently transmitted SPx, and applies the system configuration according to the received SPx.

In interval 2 (212), due to the update of SP2, the change count becomes 'N + 1' and the change bitmap becomes '0b010'. Here, the second bit of the change bitmap is changed to '1' according to the update of the SP2 as a result of a rule for notifying update of the SPx. In this case, the rule is one of toggling the bit corresponding to the updated SPx and setting the value of the bit corresponding to the updated SPx to '1'. Since the change count has increased, the UE recognizes that the system information has been updated, and determines that SP2 has been updated through the change bitmap. In addition, since the SP2 is transmitted through a frame at which the change count is increased, the terminal obtains updated system information by decoding the SP2 and stores the updated system information. At this time, since the configuration change flag is '1', the currently applied system configuration depends on the system information when the change count is 'N'. Accordingly, the terminal does not apply the stored SP2, and reflects the SP2 received in the section 1 211 to the system configuration.

In the section 3 213, the system information is not updated, but the configuration change flag is changed to '0'. Accordingly, the terminal recognizes that the system configuration according to the system information changed in the section 2 (212) is applied, and applies the SP2 received and stored in the section 2 (212).

2B shows a case where the updated SPx is transmitted after the change counter is incremented. Referring to FIG. 2B, in interval 1 221, the change count is 'N', and the change bitmap is '0b000'. At this time, since the configuration change flag is '0', the system configuration according to the SPx corresponding to the current value of the change count is applied. Therefore, a new terminal entering the base station receives the currently transmitted SPx, and applies the system configuration according to the received SPx.

In interval 2 222, due to the update of SP2, the change count becomes 'N + 1' and the change bitmap becomes '0b010'. Here, the second bit of the change bitmap is changed to '1' according to the update of the SP2 as a result of a rule for notifying update of the SPx. In this case, the rule is one of toggling the bit corresponding to the updated SPx and setting the value of the bit corresponding to the updated SPx to '1'. Since the change count has increased, the UE recognizes that the system information has been updated, and determines that SP2 has been updated through the change bitmap. However, unlike the case of FIG. 2A, the updated SP2 is not transmitted through the frame at the time when the change count is increased. However, since the configuration change flag is '1', the currently applied system configuration is applied according to the system information when the change count is 'N'. Therefore, regardless of whether the terminal receives the SP2, the terminal reflects the SP2 received in the section 1 (221) to the system configuration. After the change count and the change bitmap are changed and several super frames have elapsed, the SP2 is transmitted. Accordingly, the terminal obtains the updated system information by decoding the SP2 and stores it. In this case, since the configuration change flag is maintained as '1', the terminal does not apply the stored SP2, but applies the SP2 received in the interval 1 221.

In interval 3 (223), the system information is not updated, but the configuration change flag is changed to '0'. Accordingly, the terminal recognizes that the system configuration according to the system information updated in the section 2 (222) is applied, and applies the SP2 received and stored in the section 2 (222).

2C illustrates a case where updated SPxes are transmitted after the change counter is incremented. Referring to FIG. 2C, in the interval 1 231, the change count is 'N' and the change bitmap is '0b000'. At this time, since the configuration change flag is '0', the system configuration according to the SPx corresponding to the current value of the change count is applied. Therefore, a new terminal entering the base station receives the currently transmitted SPx, and applies the system configuration according to the received SPx.

In interval 2 (232), due to the change of SP1, SP2, and SP3, the change count becomes 'N + 1', and the change bitmap becomes '0b111'. Here, the first, second, and third bits of the changed bitmap are changed to '1' according to the update of the P1, the SP2, and the SP3, as a result of a rule for notifying the update of the SPx. In this case, the rule is one of toggling the bit corresponding to the updated SPx and setting the value of the bit corresponding to the updated SPx to '1'. Since the change count has increased, the terminal recognizes that the system information has been updated, and determines that the SP1, the SP2, and the SP3 have been updated through the change bitmap. At this time, only the SP1 is transmitted through the frame at which the change count is increased, and the SP2 and the SP3 are not transmitted. However, since the configuration change flag is '1', the currently applied system configuration is applied according to the system information when the change count is 'N'. Accordingly, the terminal decodes and stores the SP1 and reflects the SPx received in the section 1 231 to the system configuration regardless of whether the SP2 and the SP3 are received. After the change count and the change bitmap are changed and several super frames have elapsed, the SP2 and the SP3 are transmitted sequentially. Accordingly, the terminal obtains the updated system information by decoding the SP2 and the SP3, and stores it. In this case, since the configuration change flag is maintained as '1', the terminal does not apply the stored SPx, but applies the SPx received in the interval 1 231.

In interval 3 (233), the system information is not updated, but the configuration change flag is changed to '0'. Accordingly, the terminal recognizes that the system configuration according to the system information updated in the section 2 (232) is applied, and applies the SPx received and stored in the section 2 (232).

In the procedure described with reference to FIGS. 2A to 2C, the base station determines to apply a system configuration corresponding to the previous value of the change count for a predetermined period. Here, the criterion for determining whether to apply the system configuration corresponding to the previous value of the change count may vary according to the intention of the implementer of the present invention.

For example, whether to apply a system configuration corresponding to a previous value of the change count may be determined based on whether all terminals connected to the base station have received the updated SPx. In this case, the base station uses a distribution of listening intervals of sleep mode or idle mode terminals and a system configuration corresponding to the previous value of the change count by using a transmission time of the updated SPx. The application can be judged. Therefore, if all terminals have a listening period at least one of the transmission time points of the updated SPx, the base station determines to apply a system configuration corresponding to the current value of the change count.

As another example, when at least one updated SPx is not transmitted through the superframe header in which the change count and the change bitmap are changed, whether to apply a system configuration corresponding to a previous value of the change count is determined by the base station. It may be determined according to whether transmission of the at least one updated SPx is completed. In this case, after the transmission of the at least one updated SPx is completed, the base station determines to apply a system configuration corresponding to the current value of the change count.

As another example, whether to apply a system configuration corresponding to a previous value of the change count may be determined according to whether a predetermined number of super frames have elapsed from the increase of the change count. In this case, if the predetermined number of super frames have not elapsed, the base station determines to apply a system configuration corresponding to the previous value of the change count.

As another example, a system configuration corresponding to the current value of the change count may be applied at the same time as the change count increases. In this case, the base station determines to apply a system configuration corresponding to the current value of the change count from the super frame in which the change count is increased, and accordingly, sets the configuration change flag to '0'.

Hereinafter, the operation and configuration of a base station and a terminal for transmitting and receiving system information as described above will be described in detail with reference to the accompanying drawings.

3 is a flowchart illustrating a system information transmission procedure of a base station in a broadband wireless communication system according to an exemplary embodiment of the present invention.

Referring to FIG. 3, the base station determines whether a start time of the super frame has arrived in step 301. In other words, the base station checks whether a time when a super frame header should be transmitted has arrived.

If the start time of the super frame has arrived, the base station proceeds to step 303 and checks whether the system information needs to be updated. Here, the system information includes a P-SFH and an S-SFH, and the S-SFH is divided into a plurality of SPx. For example, the updating of the system information is performed by changing system settings such as subchannelization, ranging, map version, and the like. That is, the base station determines whether the update of the SPx transmitted through the super frame header is necessary due to the change of the system setting.

If it is necessary to update the system information, the base station proceeds to step 305 to update the corresponding SPx. That is, the base station updates the SPx including parameters reflecting the changed system settings. At this time, one or more SPx may be updated.

After updating the SPx, the base station proceeds to step 307 to change the change count and change bitmap. The change count and the change bitmap are parameters included in the P-SFH. The change count indicates whether or not the SPx is updated, and the change bitmap indicates the updated SPx. The change count increases in accordance with the update of the SPx, and increases only by the update count, regardless of the number of SPx updated. The change bitmap is a bit string having a length equal to the number of SPx used in the system. When the SPx is updated, a value of a position corresponding to the updated SPx is changed.

After changing the change count and the change bitmap, the base station proceeds to step 309 and determines whether to apply a system configuration corresponding to the previous value of the change count. Here, the criterion for determining whether to apply the system configuration corresponding to the previous value of the change count may vary according to the intention of the implementer of the present invention. For example, if the terminals connected to the base station have received all of the updated SPx, and if the at least one updated SPx is not transmitted through the super frame header having the change count increased, the at least one updated SPx is included. It is determined whether to apply a system configuration corresponding to the previous value of the change count according to at least one of a condition that transmission is completed and a condition that a predetermined number of super frames have elapsed from the increase of the change count. That is, when at least one of the conditions is satisfied, the base station determines to apply a system configuration corresponding to the current value of the change count.

If the system configuration corresponding to the previous value of the change count is to be applied, the base station proceeds to step 311 and sets the configuration change flag to '1'. On the other hand, when the system configuration corresponding to the current value of the change count is to be applied, the base station proceeds to step 313 and sets the configuration change flag to '0'. The configuration change flag is a parameter indicating what system configuration is applied and is included in the P-SFH.

In step 315, the base station determines whether it is necessary to transmit the SPx. For example, each SPx may be transmitted according to a unique period. In this case, the base station checks the period of each SPx and determines whether the transmission period has arrived. As another example, when a specific SPx is updated, it may be transmitted simultaneously with the update, or may be transmitted after a certain frame has elapsed after the update. If multiple SPxes are changed at the same time, the multiple SPxs cannot be transmitted in one subframe, and thus are transmitted over multiple superframes. In this case, the base station determines that it is necessary to transmit SPx sequentially in every super frame.

If the transmission of the SPx is not necessary, the base station proceeds to step 317 and transmits the P-SFH through the super frame header. Here, the P-SFH includes the change count, the change bitmap, the configuration change flag, and a scheduling information bitmap. At this time, the scheduling information bitmap is set to a value indicating that SPx is not transmitted.

On the other hand, if the transmission of the SPx is necessary, the base station proceeds to step 319 to set the scheduling information bitmap. The scheduling information bitmap is a bit string having a length equal to the number of SPx used in the system. When the SPx is transmitted, a value of a position corresponding to the transmitted SPx is set to '1'. That is, the base station generates SPx transmission information and designation information of the corresponding SPx using the scheduling information bitmap so that the terminal can decode the SPx.

After setting the scheduling information bitmap, the base station proceeds to step 321 to transmit the SPx and P-SFH corresponding to the current value of the change count through the super frame header. Here, the P-SFH includes the change count, the change bitmap, the configuration change flag, and the scheduling information bitmap.

4 is a flowchart illustrating a system information acquisition procedure of a terminal in a broadband wireless communication system according to an exemplary embodiment of the present invention.

Referring to FIG. 4, the terminal checks whether a start time of the super frame has arrived in step 401. In other words, the terminal checks whether a time point for receiving the super frame header has arrived.

If the start time of the super frame has arrived, the terminal proceeds to step 403 to decode the P-SFH. Since the P-SFH is coded with a predetermined coding scheme and received through a predetermined position of the super frame header, the terminal can decode the P-SFH without additional allocation information. By decoding the P-SFH, the terminal obtains system information, change count, change bitmap, scheduling information bitmap, and configuration change flag.

After decoding the P-SFH, the terminal proceeds to step 405 and checks whether the change count has increased. That is, the terminal compares the change count included in the previously received P-SFH with the change count included in the currently received P-SFH, and checks whether the change count has increased. If the change count has not increased, the terminal proceeds to step 409.

On the other hand, if the change count is increased, the terminal proceeds to step 407 to identify at least one SPx updated through the change bitmap. That is, the increase in the change count means updating at least one SPx. Accordingly, the UE, which has recognized the update of the at least one SPx through the increased change count, checks the updated SPx through the change bitmap included in the P-SFH. In this case, the display of the updated SPx through the change bitmap is performed by turning a bit corresponding to the updated SPx or setting a value indicating the update. In the toggled manner, the terminal checks the position of the toggled bit relative to the changed bitmap included in the previously received P-SFH to confirm what is the updated SPx. On the other hand, in the case of setting the value, the terminal checks the position of the bit set to the corresponding value (for example, '1') to confirm what is the updated SPx.

After checking the updated at least one SPx, the terminal proceeds to step 409 to determine whether the SPx not stored is transmitted. Whether the SPx is transmitted is confirmed through the scheduling information bitmap. That is, the terminal determines whether the SPx is transmitted based on whether there is a bit set to '1' in the scheduling information bitmap, and when the SPx is transmitted, the terminal determines which of the bits is set to '1'. Determine if SPx is transmitted. The terminal then checks whether the transmitted SPx is decoded and stored in the state of the current value of the change count. If the unsaved SPx is not transmitted, the terminal proceeds to step 413.

On the other hand, if the unsaved SPx is transmitted, the terminal proceeds to step 411 to decode the SPx, and stores the system information included in the SPx. At this time, since the application of the updated SPx may be delayed, the terminal does not discard the SPx before the update. That is, the terminal classifies and stores SPx according to the value of the change count. Accordingly, the terminal stores at least two types of system information, that is, system information corresponding to the current value of the change count and system information corresponding to the previous value of the change count, respectively.

In step 413, the terminal determines whether the system configuration corresponding to the previous value of the change count is applied to the super frame. At this time, whether the system configuration corresponding to the previous value of the change count is applied is confirmed through the configuration change flag.

If the system configuration corresponding to the previous value of the change count is applied, the terminal proceeds to step 415 to perform communication by applying the system configuration corresponding to the previous value of the change count. In other words, the terminal performs communication according to the system configuration according to the received SPx before the change count is increased to the current value.

On the other hand, if the system configuration corresponding to the previous value of the change count is not applied, that is, if the system configuration corresponding to the current value of the change count is applied, the terminal proceeds to step 417 to the current value of the change count. Check if all corresponding SPx is saved.

If all of the SPx corresponding to the current value of the change count have been stored, the terminal proceeds to step 419 to perform communication by applying a system configuration corresponding to the current value of the change count.

On the other hand, if all the SPx corresponding to the current value of the change count has not been stored, the terminal proceeds to step 421 and waits for reception of the SPx corresponding to the current value of the change count. In other words, the terminal stops communication until all of the SPx corresponding to the current value of the change count is stored.

5 is a block diagram of a base station in a broadband wireless communication system according to an exemplary embodiment of the present invention.

Referring to FIG. 5, the base station includes a system information determiner 502, a P-SFH generator 504, an S-SFH generator 506, a subcarrier mapper 508, an OFDM modulator 510, and a radio frequency (RF). And a transmitter 512.

The system information determiner 502 determines system information to be provided to the terminals. That is, the system information determiner 502 determines the values of parameters included in the P-SFH and the S-SFH. The system information determiner 502 updates the system information to reflect the change in system settings, and provides the P-SFH generator 504 and the S-SFH generator 506 to update the system information.

In particular, the system information determiner 502 sets the change count and the change bitmap according to whether SPx is updated, and sets the scheduling information bitmap according to whether SPx is transmitted. In addition, the system information determiner 502 sets the configuration change flag according to whether a system configuration corresponding to the previous value of the change count is applied. Here, the criterion for determining whether to apply the system configuration corresponding to the previous value of the change count may vary according to the intention of the implementer of the present invention. For example, if the terminals connected to the base station have received all of the updated SPx, and if the at least one updated SPx is not transmitted through the super frame header having the change count increased, the at least one updated SPx is included. When at least one of the condition that the transmission is completed and the condition that a predetermined number of super frames have elapsed from the increase of the change count is satisfied, the system information determiner 502 is configured to correspond to the current value of the change count. Decide to apply

The P-SFH generator 504 generates a P-SFH including system information, change counts, change bitmaps, scheduling information bitmaps, and configuration switch flags. Since the P-SFH is transmitted through a super frame header, the P-SFH generator 504 generates the P-SFH at the start of the super frame. The S-SFH generator 506 generates SPx containing system information. Since the SPx are selectively transmitted according to each unique period or defined rule, the S-SFH generator 506 generates the SPx when the transmission time arrives.

The subcarrier mapper 508 maps the transmitted signal to a resource. In particular, the subcarrier mapper 508 maps the P-SFH provided from the P-SFH generator 504 and the SPx provided from the S-SFH 506 into a super frame header. The OFDM modulator 510 converts the signals mapped to the frequency domain into a time domain signal through an inverse fast fourier transform (IFFT) operation, and generates OFDM symbols by inserting a cyclic prefix (CP). The RF transmitter 512 up-converts the OFDM symbols into a signal of an RF band, amplifies the signal, and transmits the signal through an antenna.

6 is a block diagram of a terminal in a broadband wireless communication system according to an exemplary embodiment of the present invention.

Referring to FIG. 6, the terminal includes an RF receiver 602, an OFDM demodulator 604, a subcarrier mapper 606, a P-SFH interpreter 608, an S-SFH interpreter 610, and a system information manager. 612 and controller 614.

The RF receiver 602 amplifies an RF band signal received through the antenna and downconverts the baseband signal. The OFDM demodulator 604 divides the signal from the RF receiver 602 in OFDM symbol units and restores signals mapped in the frequency domain through a fast fourier transform (FFT) operation. The subcarrier demapper 606 classifies the signals mapped to the frequency domain into processing units. For example, the processing unit may be a traffic burst, a message, or the like.

The P-SFH interpreter 608 obtains system information by demodulating and decoding the P-SFH received from the base station, and provides the obtained system information to the system information manager 612. In addition, the P-SFH interpreter 608 obtains parameters such as a change count, a change bitmap, a scheduling information bitmap, and a configuration change flag from the P-SFH, and provides the parameters to the system information manager 612. do. The S-SFH analyzer 610 obtains system information by demodulating and decoding the SPx received from the base station, and provides the obtained system information to the system information manager 612.

The system information manager 612 stores system information provided from the P-SFH interpreter 608 and the S-SFH interpreter 610, and transmits the system information to the controller 614 for operation of the terminal. to provide. In particular, the system information manager 612 uses the change count, the change bitmap, the scheduling information bitmap, and the configuration change flag to provide the stored system information to reflect the system configuration currently being applied in the system. The controller 614 controls a function for the operation of the terminal. In particular, the controller 614 controls to perform communication according to the system information provided from the system information manager 612.

The operation of the system information manager 612 for managing the system information is as follows. The system information manager 612 confirms the update of the SPx through the increase of the change count, and identifies the updated SPx through the change bitmap. When the updated SPx is identified, the system information manager 612 checks whether the unsaved SPx is transmitted through the scheduling information bitmap, and if the unsaved SPx is transmitted, the system information manager 612 decodes the SPx. 610 is controlled. When the system information included in the updated SPx is provided from the S-SFH interpreter 610, the system information manager 612 stores the system information. At this time, since the application of the updated SPx may be delayed, the terminal does not discard the SPx before the update. That is, the system information manager 612 stores at least two types of system information, that is, system information corresponding to the current value of the change count and system information corresponding to the previous value of the change count, respectively. Accordingly, the corresponding system information is provided to the controller 614. Specifically, the system information manager 612 corresponds to whether the system configuration corresponding to the previous value of the change count is applied or corresponds to the current value of the change count using the configuration change flag provided from the P-SFH interpreter 608. It determines whether the system configuration is applied, and provides the system information according to the applied system configuration to the controller 614.

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 determined not only by the scope of the following claims, but also by the equivalents of the claims.

1 is a diagram illustrating an example of a frame structure in a broadband wireless communication system according to an embodiment of the present invention;

2A to 2C are diagrams illustrating a transmission time of system information in a broadband wireless communication system according to an embodiment of the present invention;

3 is a diagram illustrating a system information transmission procedure of a base station in a broadband wireless communication system according to an embodiment of the present invention;

4 is a diagram illustrating a system information acquisition procedure of a terminal in a broadband wireless communication system according to an embodiment of the present invention;

5 is a block diagram of a base station in a broadband wireless communication system according to an embodiment of the present invention;

6 is a block diagram of a terminal in a broadband wireless communication system according to an exemplary embodiment of the present invention.

Claims (22)

A method of operating a base station in a broadband wireless communication system, Determining whether to apply a system configuration corresponding to a previous value of a change count changed according to updating of system information; Setting a configuration transition flag to a first value when applying a system configuration corresponding to a previous value of the change count; When applying a system configuration corresponding to the current value of the change count, setting the configuration change flag to a second value; And transmitting a primary-super frame header (P-SFH) including the change count and a configuration change flag set to the first value or the second value. The method of claim 1, Incrementing the change count when at least one of the SPs (SubPackets) of the Secondary-Super Frame Header (S-SFH) is updated, and Changing at least one bit corresponding to the updated at least one SP in a change bitmpa for identifying at least one updated SP; And transmitting a P-SFH including the change count and the change bitmap. The method of claim 2, And transmitting the updated at least one SP through a super frame header that transmitted the P-SFH including the change count and the change bitmap. The method of claim 2, Transmitting the updated at least one SP after transmitting the P-SFH including the change count and the change bitmap and after at least one super frame elapses. The method of claim 1, When the plurality of SPs of the SPs of the S-SFH are updated, increasing the change count; Changing a plurality of bits corresponding to the plurality of SPs in a change bitmap for identifying at least one updated SP; Transmitting a P-SFH including the change count and the change bitmap; Transmitting the plurality of SPs, one per super frame, over a plurality of super frames. The method of claim 5, After the transmission of the plurality of SPs is completed, setting the configuration switching flag to the second value; And transmitting the P-SFH including the configuration change flag set to the second value. The method of claim 1, The process of determining whether to apply a system configuration corresponding to the previous value of the change count, The condition that the terminals connected to the base station has received all the updated SPx, the transmission of the at least one updated SPx is completed when at least one updated SPx is not transmitted through the super frame header in which the change count is increased And determining to apply a system configuration corresponding to the current value of the change count when at least one of a condition and a condition that a predetermined number of super frames have elapsed from the increase of the change count is satisfied. How to. In the method of operating a terminal in a broadband wireless communication system, Checking a value of a configuration transition flag included in a primary-super frame header (P-SFH) received through a super frame header and a value of a change count changed according to an update of system information; When the value of the configuration change flag is a first value, performing communication by applying a system configuration corresponding to a previous value of the change count; And if the value of the configuration switch flag is a second value, performing communication by applying a system configuration corresponding to the current value of the change count. The method of claim 8, Decoding one of the SPs (SubPackets) of the secondary-super frame header (S-SFH); And classifying and storing the SP according to the value of the change count. 10. The method of claim 9, When the value of the change count included in the P-SFH is increased, identifying at least one updated SP among SPs of the S-SFH by using a change bitmap included in the P-SFH; , And confirming whether the updated at least one SP is transmitted through a scheduling information bitmap included in the P-SFH. The method of claim 8, If the value of the configuration change flag is a second value, checking whether all SPs corresponding to a current value of the change count are stored; If not storing all the SPs corresponding to the current value, stopping the communication until all of the SPs corresponding to the current value are stored. A base station apparatus in a broadband wireless communication system, After determining whether to apply the system configuration corresponding to the previous value of the change count changed according to the updating of the system information, and applying the system configuration corresponding to the previous value of the change count. a decision flag to set a transition flag) to a first value and to set the configuration transition flag to a second value when a system configuration corresponding to the current value of the change count is applied; And a transmitter for transmitting a Primary-Super Frame Header (P-SFH) including the change count and a configuration change flag set to the first value or the second value. The method of claim 12, The determiner is configured to increase the change count when at least one of the sub-packets (S-SFH) of the secondary super frame header (S-SFH) is updated, and to change the at least one updated SP (change bitmpa). Change at least one bit corresponding to the updated at least one SP, And the transmitter transmits a P-SFH comprising the change count and the change bitmap. The method of claim 13, And wherein the transmitter transmits the updated at least one SP through a super frame header that has transmitted a P-SFH including the change count and the change bitmap. The method of claim 13, And the transmitter transmits the updated at least one SP after transmitting a P-SFH including the change count and the change bitmap and after at least one super frame elapses. The method of claim 12, The determiner is configured to increase the change count when a plurality of SPs of S-SFH are updated, and to correspond to the plurality of SPs in a change bitmap for identifying at least one updated SP. Change them, And the transmitter transmits the plurality of SPs per super frame over a plurality of super frames after transmitting the P-SFH including the change count and the change bitmap. The method of claim 16, The determiner sets the configuration switch flag to the second value after transmission of the plurality of SPs is completed, And the transmitter transmits a P-SFH including a configuration change flag set to the second value. The method of claim 12, The determiner may be configured to receive all of the updated SPx by the terminals connected to the base station, and if at least one updated SPx is not transmitted through the super frame header having the change count increased, Determining that the system configuration corresponding to the current value of the change count is to be applied when at least one of a condition that transmission is completed and a condition that a predetermined number of super frames have elapsed from the increase of the change count is satisfied. Device. A terminal device in a broadband wireless communication system, An administrator for checking a value of a configuration transition flag included in a primary-super frame header (P-SFH) received through a super frame header and a value of a change count changed according to an update of system information; When the value of the configuration change flag is a first value, communication is performed by applying a system configuration corresponding to the previous value of the change count, and when the value of the configuration change flag is a second value, the communication value corresponds to a current value of the change count. Apparatus comprising a controller for performing communication by applying a system configuration. The method of claim 19, If one of the Sub-Packets (SP) of the Secondary-Super Frame Header (S-SFH) is received, further includes an S-SFH interpreter for decoding the SP, And the manager classifies and stores the SP according to the value of the change count. 21. The method of claim 20, The manager identifies at least one updated SP among SPs of the S-SFH by using a change bitmap included in the P-SFH when the value of the change count included in the P-SFH is increased. And checking whether the updated at least one SP is transmitted through a scheduling information bitmap included in the P-SFH. The method of claim 19, When the value of the configuration change flag is the second value, the manager determines whether all SPs corresponding to the current value of the change count are stored. If the controller does not store all the SPs corresponding to the current value, the controller stops communication until all of the SPs corresponding to the current value are stored.

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