JP5794995B2 - Apparatus and method for transmitting / receiving system information in a broadband wireless communication system - Google Patents

Description

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

  The current mobile communication system has been developed from a form mainly of existing sound communication to a form providing various services such as broadcast multimedia video and multimedia message. Such next-generation communication systems include the Institute of Electrical and Electronics Engineers (IEEE) 802.16e system and the 3GPP LTE (Long Term Evolution) IEEE 802.20 UMB (Ultra Bra) There is an IEEE 802.16m system.

  In order to support a high data transmission rate in the mobile communication system, various transfer techniques such as a multi-antenna system, HARQ (Hybrid Auto Repeat reQuest), and adaptive modulation coding (AMC) are introduced. In order for this transfer technique to operate, the base station must transmit a large amount of system information to a plurality of user terminals. The system information includes common information of the network and the cell that must be known in order for the user terminal to perform mobile communication in the cell. For example, the information includes cell bandwidth information, physical channel configuration information, higher layer parameters, and information on various transfer techniques supported by the cell, for example, the number of transfer antennas. , Multiple antenna information, HARQ related information, modulation scheme information, and the like.

  According to the IEEE (Institute of Electrical and Electronics Engineers) 802.16m standard, which is one of the wireless communication standards, the system information is P-SFC (Primary-Super Frame Header) and S-SFH (Secondary Sensor-Header). Sent in the form of The S-SFH is divided into SP1 (SubPacket1), SP2 and SP3, and the transfer periods of the SP1, SP2 and 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. The P-SFH indicates system information change using an S-SFH change count and an S-SFH SP change bitmap, and an S-SFH scheduling information bitmap. Is used to inform which SP is transmitted in the same frame.

  The S-SFH change count is mapped to the transmitted SP. For example, if the S-SFH change count is N, the transmitted SP1, SP2, and SP3 include system parameters in the “S-SFH Change Count = N” state. Therefore, changing the change count means that at least one of the SPs of the S-SFH has been updated. The S-SFH SP change bitmap indicates which SP has been changed. Each SPx also includes a 2-bit offset parameter that indicates the superframe offset at which use of the modified SP is started, and indicates when the modified new configuration is applied via the offset parameter. . Thus, after receiving the new SPx, the terminal applies the new parameter in the superframe indicated by the offset parameter in the SPx.

  The change count and change bitmap included in the P-SFH informs which SP has been updated by updating the system information. However, even if the terminal receives the P-SFH and recognizes the update of the system information and the updated SP, the terminal cannot receive the updated SPx due to the operation state such as channel degradation and slip mode. Then, communication cannot be stopped without knowing the application point (a time point of application) of the updated SPx. Accordingly, the terminal cannot communicate until the corresponding SPx is successfully decoded. Therefore, even if the updated SPx cannot be received, it is necessary to have a counter measure for recognizing the application point of the updated SPx so that the terminal can communicate before the application of the updated system information. is there.

  The object of the present invention is to solve the above-mentioned problems and disadvantages, and provides at least one of the following advantages. Accordingly, an object of the present invention is to provide an apparatus and method for notifying an application viewpoint of updated system information in a broadband wireless communication system.

  Another object of the present invention is to provide an apparatus and a method for notifying an application viewpoint of updated system information through an IE (Information Element) transmitted every superframe in a broadband wireless communication system. is there.

  It is another object of the present invention to provide an apparatus and method for updating SP (SubPacket) of a plurality of system information simultaneously in a broadband wireless communication system.

  The above object can be achieved by providing an apparatus and method for transmitting and receiving system information in a broadband wireless communication system.

  In order to achieve the above object, according to a first aspect of the present invention, a method of operating a base station in a broadband wireless communication system is provided. The method includes determining whether to apply a system configuration corresponding to a previous value of a change count that is changed according to an update of system information, and a previous value of the change count. In the case of applying a system configuration corresponding to the above, the process of setting a parameter indicating the applied system configuration as a first value, and in the case of applying the system configuration corresponding to the current value of the change count, A process of setting as a value, and a process of transmitting a primary-super frame header (P-SFH) including the change count and the parameter set as the first value or the second value.

  In order to achieve the above object, according to a second aspect of the present invention, a method of operating a terminal in a broadband wireless communication system is provided. The method includes checking a value of a parameter indicating an applied system configuration included in a P-SFH received via a superframe header and a value of a change count changed by updating system information; When the parameter value is the first value, the process of performing communication by applying the system configuration corresponding to the previous value of the change count, and when the parameter value is the second value, the current value of the change count And performing communication by applying a system configuration corresponding to the value.

  In order to achieve the above object, according to a third aspect of the present invention, a method of operating a terminal in a broadband wireless communication system is provided. The method includes a step of confirming a change count that is changed by updating system information included in a P-SFH received via a superframe header, and if the value of the change count is increased, the P-SFH Identifying an updated at least one SP among S-SFH SPs using a change bitmap included in the S-SFH; determining a transmission viewpoint of the at least one updated SP; and A process of determining a superframe to which a system configuration corresponding to the current value of the change count is applied using a transmission viewpoint, and a system configuration corresponding to the current value of the change count when the superframe arrives. And applying and communicating.

  In order to achieve the above object, according to a fourth aspect of the present invention, a base station apparatus in a broadband wireless communication system is provided. When the apparatus determines whether to apply a system configuration corresponding to the previous value of the change count changed by updating the system information, and then applies the system configuration corresponding to the previous value of the change count Determining a parameter indicating a system configuration to be applied as a first value, and applying a system configuration corresponding to the current value of the change count, a determinator for setting the parameter as a second value; and the change count And a transmitter for transmitting P-SFH including the parameter set as the first value or the second value.

  In order to achieve the above object, according to a fifth aspect of the present invention, a terminal apparatus in a broadband wireless communication system is provided. The apparatus includes a management unit that checks a value of a parameter indicating a system configuration to be applied included in a P-SFH received via a superframe header and a value of a change count that is changed by updating system information; When the parameter value is the first value, communication is performed by applying a system configuration corresponding to the previous value of the change count, and when the parameter value is the second value, the current value of the change count And a controller that performs communication by applying a system configuration corresponding to the value.

  In order to achieve the above object, according to a sixth aspect of the present invention, a terminal apparatus in a broadband wireless communication system is provided. The apparatus checks a change count that is changed by updating system information included in the P-SFH received via the superframe header, and if the change count value is increased, the change count is included in the P-SFH. The updated bit map is used to identify at least one updated SP among S-SFH SPs, determine a transmission viewpoint of the updated at least one SP, and then use the transmission viewpoint of the SP A management unit that determines a superframe to which a system configuration corresponding to the current value of the change count is applied, and a system configuration corresponding to the current value of the change count when the superframe arrives. And a controller for performing communication.

  Other aspects, benefits, and key features of the present invention should be clearly recognized by those skilled in the art from the following detailed description taken in conjunction with the accompanying examples and drawings.

  The above aspects and other aspects, features, and benefits of the present invention according to embodiments of the present invention should be readily apparent from the detailed description set forth below when taken in conjunction with the drawings in which:

FIG. 3 is a diagram illustrating an example of a frame structure in a broadband wireless communication system according to an embodiment of the present invention. It is a figure which shows the transmission time of the system information in the broadband wireless communication system by the Example of this invention. It is a figure which shows the transmission time of the system information in the broadband wireless communication system by the Example of this invention. It is a figure which shows the transmission time of the system information in the broadband wireless communication system by the Example of this invention. It is a figure which shows the procedure of the system information transmission of the base station in the broadband wireless communication system by the Example of this invention. It is a figure which shows the procedure of the system information acquisition of the terminal in the broadband wireless communication system by the Example of this invention. It is a figure which shows the block configuration of the base station in the broadband wireless communication system by the Example of this invention. FIG. 2 is a diagram illustrating a block configuration of a terminal in a broadband wireless communication system according to an embodiment of the present invention.

In the drawings, the same reference numerals are used to describe the same or similar elements, features, and structures.

  The following description with reference to the drawings is provided to assist in a comprehensive understanding of embodiments of the present invention as defined by the claims and their equivalents. The following description includes various specific details to aid understanding, but is merely taken as an example. Therefore, it goes without saying that various variations and modifications of the embodiments are possible without departing from the spirit and scope of the present invention. Also, descriptions of well-known functions and structures are omitted for clarity.

  Hereinafter, the present invention will be described with respect to a technique for notifying the application point of system information updated in a broadband wireless communication system. Hereinafter, the present invention is a frequency division multiplexing (hereinafter referred to as “OFDM”) / orthogonal frequency division multiple access (hereinafter referred to as “OFDMA” communication system). However, the present invention can also be applied to other types of wireless communication systems.

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

  As shown in FIG. 1, the super frame 100 is divided into a plurality of frames 110, and the frame 110 is divided into subframes 120 including a plurality of OFDM symbols 130. The first subframe of the first frame in the superframe 100 includes a super-frame header 140, and the superframe header 140 includes a synchronization channel and a common control channel. The super frame header 140 is an area for transmitting system information necessary for a terminal to communicate with the corresponding base station. The system information is divided into P-SFH (Primary-Super Frame Header) and S-SFH (Secondary-Super Frame Header), and the S-SFH is divided into SP (SubPacket) 1, SP2, and SP3. Hereinafter, for convenience of explanation, the present invention is referred to as SP1, SP2, and SP3.

  The P-SFH is always included in the superframe header 140, and the SPx is selectively included. For example, each SPx is transmitted in a corresponding cycle. If the SPx is included, the SPx is mapped to a resource located adjacent to the resource occupied by the P-SFH. Therefore, the terminal can extract the SPx in the frame using the SPx size information included in the P-SFH. The P-SFH and each SPx are distinguished according to the types of parameters included, and the specific parameter configuration of each IE (Information Element) may vary depending on the intention of the practitioner of the present invention. For example, the parameters included in the P-SFH and each SPx are the same as those in <Table 1> to <Table 4> below. Table 1 below is a parameter included in the P-SFH, Table 2 is a parameter included in the SP1, Table 3 is a parameter included in the SP2, and Table 4 is a parameter included in the SP3. An example of included parameters is shown.

  The base station according to the embodiment of the present invention includes a configuration transition flag (CTF) in the P-SFH. The configuration change flag is a parameter indicating whether the system configuration corresponding to the current value of the change count (S-SFH change count) is applicable, and is defined as shown in Table 5 below. The configuration change flag may be referred to as another name according to a specific embodiment. For example, the configuration change flag may be referred to as an S-SFH application hold indicator.

  When the current value of the change count is “N” and the configuration change flag is “0”, the terminal configures the system configuration corresponding to the change count “N”, that is, the system configuration based on the currently transmitted system information. Apply. On the other hand, when the current value of the change count is “N” and the configuration change flag is “1”, the terminal has a system configuration corresponding to the change count “N−1”, that is, the change count is “N−”. The system configuration based on the system information transmitted when “1” is applied.

  When the P-SFH includes the configuration change flag, system information is transmitted and received as follows.

  2 to 4 illustrate transmission points of system information in a broadband wireless communication system according to an embodiment of the present invention. FIG. 2 illustrates the case where an updated SPx is transmitted as the change counter increases.

  As shown in FIG. 2, the change count is “N” and the change bitmap is “0b000” in the first section 211. At this time, since the configuration change flag is “0”, the system configuration based on SPx corresponding to the current value of the change count is applied. Therefore, a terminal that newly enters the base station receives the SPx that is currently transmitted, and applies the system configuration based on the received SPx.

  By updating SP2 in the second section 212, the change count becomes “N + 1”, and the change bitmap becomes “0b010”. Here, the fact that the second bit of the changed bitmap is changed to “1” due to the update of SP2 is a result in accordance with a rule informing the update of SPx. 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 been increased, the terminal recognizes that the system information has been updated, and determines that SP2 has been updated via the change bitmap. Also, since the SP2 is transmitted through the frame at the time when the change count is increased, the terminal obtains updated system information by decoding the SP2 and saves it. However, since the configuration change flag is “1”, the currently applied system configuration follows the system information when the change count is “N”. Accordingly, the terminal does not apply the saved SP2, and reflects the SP2 received in the first section 211 in the system configuration.

  The system information is not updated in the third section 213, 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 second section 212 is applied, and applies the SP2 received and saved in the second section 212. As shown in FIG. 2, the configuration change flag is changed to “0” in the third section 213, but the changed bitmap continues to maintain “0b010”. However, according to another embodiment of the present invention, the change bitmap may be initialized to “0b000” while the configuration change flag is changed to “0”.

  As shown in FIG. 2, the system configuration corresponding to the current value of the change count in the embodiment is applied when the configuration change flag is changed to “0”. However, according to another embodiment of the present invention, the system configuration corresponding to the current value of the change count may be, for example, after a certain number of superframes from the time when the configuration change flag is changed to “0”. It can be applied from the next superframe.

  FIG. 3 illustrates the case where an updated SPx is transmitted after the change counter is incremented. As shown in FIG. 3, the change count is “N” and the change bitmap is “0b000” in the first interval 221. At this time, since the configuration change flag is “0”, the system configuration based on SPx corresponding to the current value of the change count is applied. Therefore, the terminal newly entering the base station receives the SPx that is currently transmitted, and applies the system configuration based on the received SPx.

  In the second section 222, the change count becomes “N + 1” by updating SP2, and the change bitmap becomes “0b010”. The fact that the second bit of the changed bitmap is changed to “1” in accordance with the update of SP2 is a result in accordance with a rule that notifies the update of SPx. 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 SP2 has been updated via the change bitmap. However, unlike the case of FIG. 2, the SP2 updated through the frame at the time when the change count is increased is not transmitted. However, since the configuration change flag is “1”, the currently applied system configuration is applied based on the system information when the change count is “N”. Therefore, the terminal reflects the SP2 received in the first section 221 in the system configuration regardless of whether the SP2 can be received. After the change count and the change bitmap are changed and several superframes have elapsed, the SP2 is transmitted. Accordingly, the terminal obtains updated system information by decoding the SP2, and saves it. At this time, since the configuration change flag is maintained at “1”, the terminal applies the SP2 received in the first interval 221 without applying the saved SP2.

  In the third section 223, the system information is not updated, but the configuration change flag is changed to “0”. Accordingly, the terminal recognizes that the system configuration based on the system information changed in the second section 222 is applied, and applies the SP2 received and saved in the second section 222. As shown in FIG. 3, the configuration change flag is changed to “0” in the third section 223, but the changed bitmap continues to maintain “0b010”. However, according to another embodiment of the present invention, the change bitmap may be initialized to “0b000” while the configuration change flag is changed to “0”.

  As shown in FIG. 3, the system configuration corresponding to the current value of the change count in the embodiment is applied when the configuration change flag is changed to “0”. However, according to another embodiment of the present invention, the system configuration corresponding to the current value of the change count may be, for example, after a certain number of superframes from the time when the configuration change flag is changed to “0”. It can be applied from the next superframe.

  FIG. 4 illustrates the case where an updated SPx is transmitted after the change counter is incremented. As shown in FIG. 4, the change count is “N” and the change bitmap is “0b000” in the first interval 231. At this time, since the configuration change flag is “0”, the system configuration based on SPx corresponding to the current value of the change count is applied. Therefore, the terminal newly entering the base station receives the SPx that is currently transmitted, and applies the system configuration based on the received SPx.

  By updating SP1, SP2 and SP3 in the second section 232, the change count becomes “N + 1” and the change bitmap becomes “0b111”. Here, the fact that the first, second, and third bits of the change bitmap are changed to “1” by updating the SP1, the SP2, and the SP3 is a result in accordance with a rule that notifies the update of the SPx. 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 the time when 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 based on the system information when the change count is “N”. Therefore, the terminal decodes and saves the SP1, and reflects the SPx received in the first section 231 in the system configuration regardless of whether the SP2 and the SP3 can be received. After the change count and the change bitmap are changed and several superframes have elapsed, the SP2 and the SP3 are sequentially transmitted. Accordingly, the terminal obtains updated system information by decoding the SP2 and the SP3, and saves the system information. At this time, since the configuration change flag is maintained at “1”, the terminal applies the SPx received in the first section 231 without applying the saved SPx.

  In the third section 233, the system information is not updated, but the configuration change flag is changed to “0”. Accordingly, the terminal recognizes that the system configuration based on the system information changed in the second section 232 is applied, and applies the SPx received and saved in the second section 232. As shown in FIG. 4, the configuration change flag is changed to “0” in the third section 233, but the changed bitmap continues to maintain “0b111”. However, according to another embodiment of the present invention, the change bitmap may be initialized to “0b000” while the configuration change flag is changed to “0”.

  As shown in FIG. 4, the system configuration corresponding to the current value of the change count in the embodiment is applied when the configuration change flag is changed to “0”. However, according to another embodiment of the present invention, the system configuration corresponding to the current value of the change count may be, for example, after a certain number of superframes from the time when the configuration change flag is changed to “0”. It can be applied from the next superframe.

  In the procedure described with reference to FIGS. 2 to 4, the base station determines to apply the system configuration corresponding to the pre-change count value for a certain period. Here, the criterion for determining whether to apply the system configuration corresponding to the previous value of the change count may vary depending on the intention of the practitioner of the present invention.

  For example, whether to apply the system configuration corresponding to the previous value of the change count may be determined based on whether all the updated SPx is received by the terminal connected to the base station. In this case, the base station responds to the previous value of the change count using the distribution of the listening period of the slip mode or idle mode terminal and the transmission point of the updated SPx. The applicability of the system configuration to be applied can be determined. Therefore, if at least one of the updated SPx transmission times has a listening interval, the base station applies a system configuration corresponding to the current value of the change count. decide.

  As another example, if at least one updated SPx is not transmitted from a superframe in which the change count and the change bitmap are changed, whether to apply a system configuration corresponding to the previous value of the change count Can 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. Specifically, the base station may apply a system configuration corresponding to the current value of the count changed from the next superframe after the updated SPx is transmitted once or twice. At this time, the base station may apply a different number of transmissions according to the type of SPx. For example, when SP1 or SP2 is changed, the base station may apply a system configuration corresponding to the current value of the changed count after the updated SP1 or SP2 completes two transmissions. When the SP3 is changed, the base station may apply a system configuration corresponding to the current value of the changed count after the updated SP3 is transmitted once. At this time, when a plurality of SPx are changed, the base station preferably applies a system configuration corresponding to the current value of the count changed at the most delayed application time among the application times by each SPx.

  As another example, whether to apply the system configuration corresponding to the previous value of the change count can be determined based on whether a predetermined number of superframes have elapsed since the increase of the change count. In this case, if the predetermined number of superframes has not elapsed, the base station decides to apply a system configuration corresponding to the previous value of the change count.

  As yet another example, a system configuration corresponding to the current value of the change count as the change count increases can be applied. At this time, the base station decides to apply the system configuration corresponding to the current value of the change count from the superframe in which the change count is increased, and thereby sets the configuration change flag to “0”. .

  As described above, the point in time when the system configuration corresponding to the changed current value of the count is applied may be determined by various methods. In the above-described embodiments, the terminal according to the updated SPx one-time or two-time transmission completion propriety, the method according to the passage of a predetermined number of superframes, the method applied with increase of the change count, etc. In some cases, it is possible to determine by itself when the system configuration corresponding to the current value of the change count is applied. In this case, the terminal may apply a system configuration corresponding to the current value of the change count at the time when it is determined by itself without referring to the configuration change flag.

  For example, the case of a method according to whether or not the updated SPx can be transmitted is described as follows. Since each SPx, that is, SP1, SP2, and SP3, is transmitted at a constant superframe interval according to each period, the terminal calculates a superframe in which the corresponding SPx is received using the superframe number and the transmission period of each SPx. Can do. Therefore, the terminal recognizes the updated SPx through the change bitmap, calculates the transmission time of the SPx, and then corresponds to the current value of the change count from the superframe next to the superframe in which the SPx is transmitted. Apply the system configuration. Specifically, when the change bitmap is “0b010”, the terminal determines that SP2 has been updated via the change bitmap. Then, the terminal calculates the next SP2 transmission time using the current superframe number and the transmission cycle of the SP2, and the updated SP2 starts from the superframe next to the superframe in which two transmissions are completed. A system configuration corresponding to the current value of the change count reflecting the updated SP2 is applied.

  Hereinafter, as described above, the present invention will be described in detail with reference to the drawings, the operation and configuration of a base station and a terminal that transmit and receive system information.

  FIG. 5 illustrates a procedure for transmitting base station system information in a broadband wireless communication system according to an embodiment of the present invention.

  As shown in FIG. 5, the base station checks in step 301 whether the start time of the superframe has arrived. In other words, the base station checks whether it is time to send a superframe header.

  When the start time of the superframe has arrived, the base station proceeds to step 303 and confirms whether the system information needs to be updated. Here, the system information includes P-SFH and S-SFH, and the S-SFH is divided into a plurality of SPx. For example, the update of the system information is configured by changing a system setting such as a subchannel definition method (subchannelization) range method, a map version, or the like. That is, the base station determines whether it is necessary to update SPx transmitted via the superframe header due to a change in system settings.

  If the system information needs to be updated, the base station proceeds to step 305 and updates the corresponding SPx. That is, the base station updates SPx including parameters that reflect the changed system settings. At this time, one or a plurality of SPx may be updated.

  After updating the SPx, the base station proceeds to step 307 to change the change count and the change bitmap. The change count and the change bitmap are parameters included in the P-SFH. The change count indicates whether or not SPx can be updated, and the change bitmap indicates the updated SPx. The value of the change count is increased by updating SPx, and is increased only by the number of updates regardless of the number of SPx to be updated. The change bitmap is a bit string having a length as long as the number of SPx used in the system, and the value of the position corresponding to the SPx updated at the time of SPx update is changed.

  After changing the change count and the change bitmap, the base station proceeds to step 309 and determines whether to apply the system configuration corresponding to the previous value of the change count. Here, a criterion for determining whether to apply a system configuration corresponding to the previous value of the change count may vary depending on a specific embodiment. For example, a condition that a terminal connected to the base station has received all updated SPx, a condition that at least one updated SPx has been transmitted N times or more after the change count has increased, and the change It is determined whether to apply the system configuration corresponding to the previous value of the change count according to at least one of the conditions that a predetermined number of superframes have elapsed since the count increase. That is, if 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 a system configuration corresponding to the previous value of the change count is to be applied, the base station proceeds to step 311 and indicates a parameter indicating the system configuration to be applied, for example, a configuration change flag or S-SFH application pending. Set the indicator 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 or the S-SFH application hold indicator is a parameter indicating which system configuration is applied, and is included in the P-SFH. Hereinafter, for convenience of explanation, the present invention refers to the parameter as a configuration change flag.

  Thereafter, the base station proceeds to step 315 and determines whether it is necessary to transmit SPx. For example, each SPx may be transmitted with a unique period. In this case, the base station confirms the period of each SPx and determines whether the transmission period has arrived. As another example, when the specific SPx is updated, it may be transmitted together with the update, or may be transmitted after a certain frame elapses after the update. If a plurality of SPx are changed at the same time, the plurality of SPx cannot be transmitted through one subframe, and thus transmitted over a plurality of superframes. In this case, the base station determines that it is necessary to sequentially transmit SPx for each superframe.

  If transmission of the SPx is not necessary, the base station proceeds to step 317 and transmits P-SFH via a superframe 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 as a value indicating that SPx is not transmitted.

  On the other hand, if transmission of the SPx is necessary, the base station proceeds to step 319 and sets the scheduling information bitmap. The scheduling information bitmap is a bit string having a length as long as the number of SPx used in the system, and the value of the position corresponding to the SPx transmitted when transmitting the SPx is set to “1”. The That is, the base station generates the SPx transmission information and the SPx designation information 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 and transmits SPx and P-SFH corresponding to the current value of the change count through the superframe header. Here, the P-SFH includes the change count, the change bitmap, the configuration change flag, and the scheduling information bitmap.

  FIG. 6 illustrates a procedure for acquiring system information of a terminal in a broadband wireless communication system according to an embodiment of the present invention.

  As shown in FIG. 6, the terminal checks in step 401 whether the start time of the superframe has arrived. In other words, the terminal confirms whether a time point for transmitting a superframe header has arrived.

  If the start time of the superframe arrives, the terminal proceeds to step 403 and decodes P-SFH. Since the P-SFH is coded using a predetermined coding scheme and is received via a predetermined position of the superframe header, the terminal can decode the P-SFH without additional allocation information. You can in. By decoding the P-SFH, the terminal obtains parameters indicating system information, change count, change bitmap, scheduling information bitmap, and applied system configuration. Here, the parameter indicating the applied system configuration may be referred to as a configuration change flag or an S-SFH application hold indicator. Hereinafter, for convenience of explanation, the present invention refers to the parameter as a configuration change flag.

  After decoding the P-SFH, the terminal proceeds to step 405 to check 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 to check 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 has increased, the terminal proceeds to step 407 and confirms at least one SPx updated through the change bitmap. That is, an increase in the change count means an update of at least one SPx. Accordingly, the terminal, which has recognized the update of at least one SPx through the increased change count, checks which SPx has been updated through the change bitmap included in the P-SFH. At this time, the SPx updated via the changed bitmap is displayed by the bit corresponding to the updated SPx being toggled or set as a value indicating the update. In the case of the toggled scheme, the UE determines which SPx has been updated by checking the position of the bit that has been toggled against the modified bitmap included in the previously received P-SFH. . On the other hand, when the value is set, the terminal confirms which SPx has been updated by confirming the position of the bit set to the corresponding value (eg, “1”).

  After confirming the updated at least one SPx, the terminal proceeds to step 409 and confirms whether the SPx is transmitted unless it is saved. Whether or not the SPx can be transmitted is confirmed via the scheduling information bitmap. That is, if the terminal determines whether the SPx can be transmitted based on whether there is a bit set to “1” in the scheduling information bitmap and sets the SPx to “1”. It is determined which SPx is transmitted via the position of the designated bit. Then, the terminal confirms whether decoding and saving are possible with the SPx to be transmitted in the state of the current value of the change count. If SPx is not transmitted unless saved, the terminal proceeds to step 413.

  On the other hand, if SPx is transmitted unless it is saved, the terminal proceeds to step 411, decodes the SPx, and then saves system information included in the SPx. At this time, since the updated SPx may be applied later, the terminal does not discard the SPx before the update. That is, the terminal classifies and saves SPx according to the value of the change count. Therefore, the terminal saves at least two pieces 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.

  Subsequently, the terminal proceeds to step 413 to check whether the system configuration corresponding to the previous value of the change count is applied in this superframe. At this time, according to the embodiment of the present invention, whether the system configuration corresponding to the previous value of the change count is applicable is confirmed via the configuration change flag. Meanwhile, according to another embodiment of the present invention, the terminal may determine whether to apply the system configuration corresponding to the previous value of the change count according to a predetermined condition without using the configuration change flag. For example, when the condition that at least one update SPx is transmitted N times or more after the change count is increased, the system configuration corresponding to the current value of the change count is applied. In this case, after confirming at least one SPx updated in step 407, the terminal calculates a next transmission time of the updated at least one SPx. Then, the terminal determines to apply a system configuration corresponding to the previous value of the change count until a superframe in which the updated at least one SPx is transmitted N times. In this case, the N may be 2 for SP1 or SP2 and 1 for SP3.

  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 communicates with the system configuration according to the SPx received 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, in other words, if the system configuration corresponding to the current value of the change count is applied, the terminal proceeds to step 417 to change the count. Check whether all SPx corresponding to the current value have been saved.

  If all SPx corresponding to the current value of the change count are saved, the terminal proceeds to step 419 to perform communication by applying the 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 have not been saved, 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 suspends communication until the change count saves all SPx corresponding to the current value.

  FIG. 7 illustrates a block configuration of a base station in a broadband wireless communication system according to an embodiment of the present invention.

  As shown in FIG. 7, the base station includes a system information determiner 502, a P-SFH generator 504, an S-SFH generator 506, a subcarrier mapping machine 508, an OFDM modulator 510, and an RF (Radio Frequency) transmitter. 512 is comprised.

  The system information determiner 502 determines system information provided to the terminal. That is, the system information determiner 502 determines the parameter values included in the P-SFH and S-SFH. The system information determinator 502 updates the system information to reflect changes in system settings, and provides system information updates to the P-SFH generator 504 and the S-SFH generator 506.

  In particular, the system information determiner 502 sets the change count and the change bitmap according to whether SPx can be updated, and sets the scheduling information bitmap according to whether SPx can be transmitted. In addition, the system information determiner 502 sets the configuration change flag according to whether the system configuration corresponding to the previous value of the change count is applicable. Here, a criterion for determining whether to apply a system configuration corresponding to the previous value of the change count may vary depending on a specific embodiment. For example, a condition that a terminal connected to the base station has received all updated SPx, a condition that at least one update SPx has been transmitted N times or more after the change count has increased, and the change count If at least one of the conditions that a predetermined number of superframes has passed since the increase is satisfied, the system information determiner 502 determines to apply the system configuration corresponding to the current value of the change count.

  The P-SFH generator 504 generates a P-SFH including system information, a change count, a change bitmap, a scheduling information bitmap, and a configuration change flag. Since the P-SFH is transmitted via 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 including system information. Since the SPx is selectively transmitted according to each natural period or a predetermined rule, the S-SFH generator 506 generates the SPx when a transmission time point arrives.

  The subcarrier mapping unit 508 maps a transmission signal to a resource. In particular, the subcarrier mapping unit 508 maps the P-SFH provided from the P-SFH generator 504 and the SPx superframe header provided from the S-SFH 506. The OFDM modulator 510 converts a signal mapped in the frequency domain through an IFFT (Inverse Fast Fourier Transform) operation into a time domain signal, and generates an OFDM symbol by inserting a CP (Cyclic Prefix). The RF transmitter 512 uplink-converts the OFDM symbol with an RF band signal, amplifies the signal, and transmits the amplified signal through an antenna.

  FIG. 8 illustrates a block configuration of a terminal in a broadband wireless communication system according to an embodiment of the present invention.

  As shown in FIG. 8, the terminal includes an RF receiver 602, an OFDM demodulator 604, a subcarrier demapping machine 606, a P-SFH analyzer 608, an S-SFH analyzer 610, a system information manager 612, and a controller. 614.

  The RF receiver 602 amplifies an RF band signal received through an antenna and performs downlink conversion to a baseband signal. The OFDM modulator 604 divides the signal from the RF receiver 602 into OFDM symbol units, and restores the signal mapped in the frequency domain through FFT (Fast Fourier Transform) operation. The subcarrier demapping unit 606 classifies the signal mapped in the frequency domain into processing units. For example, the processing unit may include a traffic burst, a message, and the like.

  The P-SFH analyzer 608 acquires system information by demodulating and decoding the P-SFH received from the base station, and provides the acquired system information to the system information manager 612. The P-SFH analyzer 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. The S-SFH analyzer 610 acquires system information by demodulating and decoding the SPx received from the base station, and provides the acquired system information to the system information manager 612.

  The system information manager 612 saves system information provided from the P-SFH analyzer 608 and the S-SFH analyzer 610 and provides the system information to the controller 614 for operation of the terminal. To do. In particular, the system information manager 612 uses the change count, the change bitmap, the scheduling information bitmap, and the configuration change flag to save system information that reflects the system configuration currently applied in the system. I will provide a. The controller 614 controls functions for the operation of the terminal. In particular, the controller 614 controls to perform communication according to 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 SPx through the increase of the change count, and identifies the SPx updated through the change bitmap. When the updated SPx is identified, the system information manager 612 checks whether the SPx is transmitted unless it is saved via the scheduling information bitmap, and if the SPx is transmitted unless it is saved, the SPx is changed to the SPx. The S-SFH analyzer 610 is controlled to perform decoding. When the system information included in the updated SPx is provided from the S-SFH analyzer 610, the system information manager 612 saves the system information. At this time, since the updated SPx may be applied later, the terminal does not discard the SPx before the update. That is, the system information manager 612 saves and applies at least two pieces 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. The corresponding system information is provided to the controller 614. Specifically, the system information manager 612 is provided with a system configuration corresponding to the previous value of the change count using the configuration change flag provided from the P-SFH analyzer 608, or changed. It is determined whether or not system information corresponding to the current value of the count is applied, and system information based on the applied system configuration is provided to the controller 614. However, according to another embodiment of the present invention, the system information manager 612 determines whether to apply a system configuration corresponding to the previous value of the change count according to a predetermined condition without using the configuration change flag. May be. For example, when the condition that at least one update SPx is transmitted N times or more after the change count is increased, the system configuration corresponding to the current value of the change count is applied. In this case, the system information manager 612 checks the updated at least one SPx through the changed bitmap, and then calculates the next transmission time of the updated at least one SPx. Then, the system information manager 612 determines to apply the system configuration corresponding to the previous value of the change count up to the superframe in which the updated at least one SPx is transmitted N times. In this case, the N may be 2 for SP1 or SP2 and 1 for SP3.

  By notifying the terminal of the application time point of the system information updated in the broadband wireless communication system, it is possible to minimize the inoperable state due to the non-reception of the system information. In particular, in a terminal that has resumed communication after being interrupted for a while, such as idle mode or slip mode, the present invention recognizes the change of system information and applies the changed system information. It is an effective way to know.

  On the other hand, in the detailed description of the present invention, specific embodiments have been described, but it is needless to say that various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be determined only by the embodiments described, but should be determined not only by the claims described below, but also by the equivalents thereof.

100 Superframe 110 Frame 120 Subframe 130 OFDM symbol 140 Superframe header 602 RF receiver 604 OFDM demodulator 606 Subcarrier mapping machine 608 P-SFH analyzer 610 S-SFH analyzer 612 System information manager 614 Controller

Claims (24)

In an operation method of a base station in a wireless communication system,
Generating system information including a first parameter set (set) and a second parameter set;
Transmitting the system information, and
The first parameter set includes an indicator, a change count , a change bitmap, and scheduling information .
The indicator instructs the to Rukoto apply the contents of the second parameter set corresponding to the second value of said change count (contents),
The second value is a previous value of the change count set to the current first value,
The method of claim 2, wherein the second value is different from the first value .   The method of claim 1, further comprising increasing the change count when the second parameter set is changed. The second parameter set is divided into a number of SPs (Sub Packets),
Changing at least one of the SPs;
A step of changing at least one bit is corresponding to at least one SP said changed bitmap or al the changes to identify a change in SP, further comprising a,
The method of claim 1, wherein the modified bitmap is transmitted via the first parameter set. Changing the second parameter set;
The method of claim 1, further comprising determining whether to apply the contents of the changed second parameter set. The second parameter set is divided into a number of SPs (Sub Packets),
The process of determining whether to apply the contents of the changed second parameter set includes:
After the SP has been changed, when a predetermined number of changed SP transmissions are completed,
5. The method of claim 4, further comprising determining to apply the contents of the modified second parameter set. The SP includes SP1, SP2, and SP3 having different transmission periods,
When the SP1 is changed, the contents of the changed SP1 are applied from the superframe next to the superframe in which the changed SP1 is transmitted twice;
When the SP2 is changed, the contents of the changed SP2 are applied from the superframe next to the superframe in which the changed SP1 is transmitted twice;
6. The method of claim 5, wherein when the SP3 is changed, the contents of the changed SP3 are applied from a superframe next to a superframe in which the changed SP1 is transmitted twice. . The second parameter set includes a number of SPs;
The method of claim 1, further comprising: transmitting the modified at least one SP when a transmission period of the modified at least one SP arrives. In an operation method of a terminal in a wireless communication system,
Receiving system information including a first parameter set and a second parameter set ;
The first parameter set includes an indicator, a change count, a change bitmap, and scheduling information.
The indicator instructs to apply contents of a second parameter set corresponding to a second value of the change count;
The method wherein the second value is different from the first value . The second parameter set is divided into a number of SPs (Sub Packets),
Further comprising the step of receiving the modified bitmap for identifying the modified SP,
The method of claim 8 , wherein the modified bitmap is included in the first parameter set. The method of claim 9 , further comprising determining whether to change system information included in the SP using the change count, the change bitmap, and the indicator. The process of determining whether to change the system information included in the SP using the change count, the change bitmap, and the indicator,
Comparing the previous change count value and the current change count value;
If the difference between the previous change count value and the current change count value is 0, discarding the SP received while the change count value is not changed;
If the difference between the previous change count value and the current change count value is 1, changing the content of the system information included in the SP corresponding to the bit whose value has been changed from the change bitmap;
11. The method according to claim 10 , further comprising: changing contents of system information included in all SPs if a difference between the previous change count value and the current change count value is 2 or more. 9. The method of claim 8 , wherein the change count is increased by changing the second parameter set. In a base station apparatus in a wireless communication system,
A generating unit for generating system information including a first parameter set (set) and a second parameter set;
A transmission unit for transmitting the system information,
The first parameter set includes an indicator, a change count, a change bitmap, and scheduling information.
The indicator instructs to apply contents of a second parameter set corresponding to a second value of the change count;
The second value is a previous value of the change count set to the current first value,
The apparatus wherein the second value is different from the first value . The apparatus of claim 13 , further comprising a determination unit that increases the change count when the second parameter set is changed. The second parameter set is divided into a number of SP (sub packet),
Change at least one of the SPs;
Further comprising the modified bitmap determining unit for changing at least one bit is corresponding to at least one SP is flop or al the changes for identifying the modified SP,
The apparatus of claim 13 , wherein the modified bitmap is included in the first parameter set. The apparatus of claim 13 , further comprising a determining unit that changes the second parameter set and determines whether to apply the contents of the changed second parameter set. The second parameter set is divided into a number of SPs (Sub Packets),
The determination unit determines to apply the contents of the changed second parameter set when the SP transmission is changed a predetermined number of times after the SP is changed. The apparatus according to claim 16 . The SP includes SP1, SP2, and SP3 having different transmission periods,
When the SP1 is changed, the contents of the changed SP1 are applied from the superframe next to the superframe in which the changed SP1 is transmitted twice;
When the SP2 is changed, the contents of the changed SP2 are applied from the superframe next to the superframe in which the changed SP1 is transmitted twice;
The apparatus of claim 17 , wherein when the SP3 is changed, the contents of the changed SP3 are applied from a superframe next to a superframe in which the changed SP1 is transmitted twice. . The second parameter set includes a number of SPs;
The apparatus of claim 13 , wherein the transmission unit transmits the changed at least one SP when a transmission period of the changed at least one SP arrives. In a terminal device in a wireless communication system,
A receiving unit for receiving system information including a first parameter set (set) and a second parameter set ;
The first parameter set includes an indicator, a change count, a change bitmap, and scheduling information.
The indicator instructs to apply contents of a second parameter set corresponding to a second value of the change count;
The second value is a previous value of the change count set to the current first value,
The apparatus wherein the second value is different from the first value . The second parameter set is divided into a number of SPs (Sub Packets),
The receiving unit receives the change bitmap for identifying the modified SP,
The apparatus of claim 20 , wherein the modified bitmap is included in the first parameter set. A control unit, said change count, said change bitmap apparatus of claim 21, wherein the determining whether to change the system information included in the SP using the indicator. The control unit compares the previous change count value and the current change count value, and if the difference between the previous change count value and the current change count value is 0, the change count value is not changed. If the difference between the previous change count value and the current change count value is 1, the SP corresponding to the bit whose value has been changed from the change bitmap is discarded. If the difference between the previous change count value and the current change count value is 2 or more, the content of the system information included in all SPs is changed. The apparatus of claim 22 . 21. The apparatus of claim 20 , wherein the change count is increased by changing the second parameter set.

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