WO2009082184A2

WO2009082184A2 - Method for determining spurious and wireless communication system applying that method

Info

Publication number: WO2009082184A2
Application number: PCT/KR2008/007723
Authority: WO
Inventors: Hyung Joon Jeon; Jae Hyeong Kim; Dong Kwan Lee
Original assignee: Posdata Co., Ltd.
Priority date: 2007-12-26
Filing date: 2008-12-26
Publication date: 2009-07-02
Also published as: WO2009082184A3

Abstract

A method for determining a spurious emission and a wireless communication system applying that method is disclosed, which is capable of determining whether or not there is the spurious emission in each base station by determining whether or not there is a signal in a zone allocated to a predetermined region of an uplink transmission period of each base station frame, the method comprising requesting an allocation of a first zone in an uplink transmission period in a frame of each BS, wherein data bursts are not allocated into the first zone; receiving a first N level measured in the first zone from each BS; and determining whether or not there is the spurious emission in each BS using the first N level.

Description

METHOD FOR DETERMINING SPURIOUS AND WIRELESS COMMUNICATION SYSTEM APPLYING

THAT METHOD

Technical Field

[1] The present invention relates to a wireless communication system, and more particularly, to a method and apparatus for determining a spurious emission in a base station of a wireless communication system.

[2]

Background Art

[3] As shown in FIG. 1, general third and fourth generation wireless communication systems are based on a multi-cell structure, wherein each cell is managed by a base station located therein.

[4] In the wireless communication system based on the multi-cell structure, there is interference among the neighboring base stations. As a distance between the base stations becomes shorter, the interference therebetween becomes more severe. For example, in case of the base station "C", the interference with the base station "A" is more severe than the interference with the base station "B".

[5] In the meantime, each base station can be affected by the interference from other apparatus included in other kinds of wireless communication system, or other apparatus located adjacent to the base station, for example, streetlamps. At this time, an interference signal generated from any other apparatus except for the base station is not a frequency required for the wireless communication system, whereby the interference signal is referred to as a spurious emission.

[6] However, the spurious emission generated by the other apparatus except for the base station is different from the interference signal between the base stations in that the spurious emission is generated irrelevantly to a service provision of the wireless communication system. Thus, the spurious emission has to be removed.

[7] Accordingly, it is necessary for each base station to determine whether or not there is the spurious emission. However, since the spurious emission is received together with the interference signal between the base stations, it is difficult to differentiate the spurious emission, generated from the other apparatus except for the base station, from the interference signals received in each base station. There is an increasing re- quirement for a method to differentiate the spurious emission from the interference signals received in each base station, that is, to determine the spurious emission.

[8]

Disclosure of Invention Technical Problem

[9] Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a method for determining a spurious emission and a wireless communication system applying that method, which is capable of preventing one or more problems of the related art.

[10] An object of the present invention is to provide a method for determining a spurious emission and a wireless communication system applying that method, which is capable of determining whether or not there is the spurious emission in each base station by determining whether or not there is a signal in a zone allocated to a predetermined region of an uplink transmission period of each base station frame.

[11] Another object of the present invention is to provide a method for determining a spurious emission and a wireless communication system applying that method, which is capable of determining whether or not there is the spurious emission in each base station by determining whether or not there is a signal in a transmit/receive transition gap of a neighboring base station frame in the specific base station.

[12]

Technical Solution

[13] To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a method for determining a spurious emission in a wireless communication system comprises requesting an allocation of a first zone in an uplink transmission period in a frame of each BS, wherein data bursts are not allocated into the first zone; receiving a first N level measured in the first zone from each BS; and determining whether or not there is the spurious emission in each BS using the first N level.

[14] At this time, it is determined that there is the spurious emission in the predetermined

BS when the first N level measured in the predetermined BS is more than a first reference value, the first N level measured in the predetermined BS is different from a prior first N level received from the predetermined BS, or a difference between the first N level measured in the predetermined BS and an average of N levels received from the other BSs excluding the predetermined BS is more than a second reference value in the step of determining whether or not there is the spurious emission.

[15] Also, a second N level measured in the remaining region excluding the first zone in the uplink transmission period of each BS is received with the first N level from each BS in the step of receiving the first N level, and wherein it is determined that the spurious emission is received in the predetermined BS when a difference between the first N level and the second N level received from the predetermined BS is less than a reference value in the step of determining whether or not there is the spurious emission.

[16] Furthermore, the method comprises synchronizing the BSs before requesting the allocation of the first zone in the uplink transmission period in the frame of each BS.

[17] At this time, the first zone is allocated to a region including the final symbol duration of the uplink transmission period for each BS, and a location and size of the first zone are identically set in all BSs.

[18] In addition, the method further comprises requesting a change in ratio of downlink transmission period to uplink transmission period in each BS so that the uplink transmission period of each BS is relatively increased more than a normal uplink transmission period by a predetermined value before requesting the allocation of the first zone in the uplink transmission period in the frame of each BS.

[19] At this time, the first zone is allocated as a sounding zone in the step of requesting the allocation of the first zone in the uplink transmission period in the frame of each BS.

[20] Also, sounding command Es for the sounding zone are not generated.

[21] The wireless communication system is based on at least one of EEE 802.16d/e standard, Wibro, and WiMax.

[22] In another aspect of the present invention, a method for determining a spurious emission in a wireless communication system comprises allocating a first zone to determine whether or not there is the spurious emission in an uplink transmission period; generating a BS frame, wherein uplink data bursts are allocated in a data region excluding the first zone in the uplink transmission period of the BS frame; and measuring an N level in the first zone to determine whether or not there is the spurious emission.

[23] In another aspect of the present invention, a method for determining a spurious emission in a wireless communication system comprises adjusting a ratio of downlink transmission period to uplink transmission period in a first BS frame so as to be included a TTG of a second BS frame of a neighbor second BS in the uplink transmission period of the first BS frame when a first BS receives a command to determine whether or not there is the spurious emission; and determining whether or not there is the spurious emission in the first BS using an N level of the first BS, wherein the N level of the first BS is measured in the uplink transmission period of the first BS frame.

[24] In another aspect of the present invention, a method for determining a spurious emission in a wireless communication system comprises changing a ratio of άλvnlink transmission period to uplink transmission period so as to adjust a location of a TTG in a BS frame, wherein the BS frame includes the uplink transmission period, the TTG, and the άλvnlink transmission period; and measuring an N level in the uplink transmission period of the BS frame so as to determine whether or not there is the spurious emission.

[25] In another aspect of the present invention, a wireless communication system comprises a BS including a means for allocating a zone and a means for measuring an N level; and an NMS configured to determine whether or not there is the spurious emission in the BS using the N level transmitted from the BS, wherein the means for allocating the zone allocates a first zone into which uplink data-bursts are not allocated to an uplink transmission period of a BS frame so as to determine whether or not there is the spurious emission is when receiving a command to determine whether or not there is the spurious emission, and the means for measuring the N level measures the N level in the first zone to transmit the measured N level to the NMS.

[26] In another aspect of the present invention, a wireless communication system comprises a BS including a means for adjusting a ratio of άλvnlink transmission period to uplink transmission period and a means for measuring an N level; and an NMS configured to determine whether or not there is the spurious emission in the BS using the N level transmitted from the BS, wherein the means for adjusting the ratio of downlink transmission period to uplink transmission period adjusts the ratio of downlink transmission period to uplink transmission period so as to include a TTG of a neighboring BS frame in the uplink transmission period of the BS when receiving a command to determine whether or not there is the spurious emission, and the means for measuring the N level measures the N level in the uplink transmission period to transmit the measured N level to the NMS.

[27]

Advantageous Effects

[28] According to the present invention, the spurious emission can be determined in the corresponding base station by allocating the zone, into which data bursts are not allocated, to the predetermined region of the uplink transmission period of each BS, and determining whether or not there is a signal in the corresponding zone; or the spurious emission can be determined in the corresponding base station by determining whether or not there is the signal in the TTG of the neighboring BS frame in the specific BS, whereby it is possible to reduce a cost for determining whether or not there is the spurious emission.

[29] Since whether or not there is the spurious emission can be determined by allocating the sounding zone to the uplink transmission period of the BS, it is possible to decrease the number of symbols used for determining whether or not there is the spurious emission in the uplink transmission period.

[30] Also, the TTG of the neighboring BS frame is included in the uplink transmission period of the specific BS frame by adjusting the ratio of cbwnlink transmission period to uplink transmission period in the specific BS frame, whereby it is possible to determine whether or not there is the signal in the specific BS in the TTG of the neighboring BS frame.

[31] The data bursts are not allocated to the first slot of the uplink transmission period or the final slot of the cbwnlink transmission period in the neighboring BSs. Thus, even though there is the propagation delay, it is possible to determine whether or not there is the spurious emission in the specific BS.

[32]

Brief Description of Drawings

[33] FIG. 1 illustrates a cell arrangement in a general wireless communication system.

[34] FIG. 2 is a block diagram schematically illustrating a wireless communication system according to the first embodiment of the present invention.

[35] FIG. 3 illustrates a frame structure in each base station according to the first embodiment of the present invention.

[36] FIG. 4 is a flow chart illustrating a method for determining whether or not there is a spurious emission according to the first embodiment of the present invention.

[37] FIG. 5 is a block diagram schematically illustrating a wireless communication system according to the second embodiment of the present invention.

[38] FIG. 6 illustrates one example showing a frame structure of a base station to be a target of determination whether or not there is a spurious emission, and other frame structures of neighboring base stations.

[39] FIG. 7 illustrates another example showing a frame structure of a base station to be a target of determination whether or not there is a spurious emission, and other frame structures of neighboring base stations.

[40] FIG. 8 illustrates a frame structure of each base station when a propagation delay is generated.

[41] FIG. 9 illustrates another example showing a frame structure of a base station to be a target of determination whether or not there is a spurious emission, and other frame structures of neighboring base station in the wireless communication system according to the second embodiment of the present invention.

[42] FIG. 10 a flow chart illustrating a method for determining whether or not there is a spurious emission in the wireless communication system according to the second embodiment of the present invention.

[43]

Best Mode for Carrying out the Invention

[44] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

[45] For convenience of explanation, it is assumed that a wireless communication system according to the present invention corresponds to a wireless communication system based on EEE 802.16d/e, Wibro, or WiMax, especially, wireless communication system based on a time division duplex (hereinafter, referred to as "TTD") where an amount of unlink data transmitted from a mobile station to a base station and an amount of downlink data transmitted from the base station to the mobile station are asymmetric. However, it is not limited to this. Furthermore, the present invention can be applicable to various types of wireless communication system. That is, the present invention can be applied to a wireless communication system based on a frequency division duplex (hereinafter, referred to as "FDD") as well as the wireless communication system based on the TDD.

[46] In the meantime, supposing that all base stations comprised in the wireless communication system according to the present invention are synchronized to the time.

[47] [First Embodiment]

[48] FIG. 2 is a block diagram schematically illustrating a wireless communication system according to the first embodiment of the present invention, which is capable of determining whether or not there is a spurious emission.

[49] As shown in FIG. 2, the wireless communication system according to the first embodiment of the present invention includes a base station 100 (hereinafter, referred to as "BS"), an element management server 110 (hereinafter, referred to as "EMS"), and a network management server 120 (hereinafter, referred to as "NMS").

[50] The BS 100 functions as an intermediate means for transmitting and receiving data so as to transmit the data to a mobile station (not shown) with high efficiency. The BS 100 includes various elements for performing the intermediate function related with the data receiving and transmission.

[51] Herein, for convenience of explanation, only elements for determining whether or not there is the spurious emission will be explained as follows.

[52] As shown in the figure 2, the BS 100 to be a target for determination whether or not there is the spurious emission may includes a spurious-emission determining scheduler 102; a zone allocating means 104; a symbol-ratio changing means 105; a data-burst allocating means 106; and an N-level measuring means 108.

[53] First, the spurious -emission determining scheduler 102 receives a command to determine whether or not there is the spurious emission received from the EMS 110 or NMS 120, and determines a timing for determining whether or not there is the spurious emission according to the received command.

[54] In one embodiment of the present invention, the command may be provided to the spurious-emission determining scheduler 102 while being included in a configuration file provided by the EMS 110; or may be provided to the spurious-emission determining scheduler 102 from the NMS 120 through the EMS 110 when the command is input to the NMS 120 by a network manager.

[55] The zone allocating means 104 allocates a zone for determining whether or not there is the spurious emission in an uplink transmission period using zone switch in an uplink transmission period when the command is received through the spurious- emission determining scheduler 102. In this case, the zone for determining whether or not there is the spurious emission (hereinafter, referred to as "first zone") indicates a region in which is not allocated with uplink data bursts (hereinafter, referred to as "data burst") by the data-burst allocating means 106.

[56] In the present invention, the zone is allocated to a predetermined region of the uplink transmission period in a BS frame, and the data burst is not allocated into the corresponding zone, whereby no signal is received in the BS of the corresponding zone. If a signal is detected in the corresponding zone, it is determined that there is the spurious emission in the BS.

[57] At this time, both a symbol offset of the first zone and the number of symbols comprised in the first zone are identically set in the uplink transmission period for all BSs. Also, the symbol offset of the first zone and the number of symbols comprised in the first zone may be included in the command to determine whether or not there is the spurious emission.

[58] In one embodiment of the present invention, the zone allocating means 104 may allocate the first zone to a region including a final symbol-duration of the uplink transmission period. For example, in case of the general Wibro or WiMax system, data is allocated by each unit of three symbols in the uplink transmission period. Thus, the zone allocating means 104 can allocate the first zone to the final three symbol durations of the uplink transmission period.

[59] A method for allocating the first zone to the uplink transmission period by the zone allocating means 104 will be explained with reference to FIG. 3. As shown in the drawing, the first zone for determining whether or not there is the spurious emission is allocated to the region including the final symbol duration in the uplink transmission periods of the BSs of A, B, and C. Also, since both the symbol offset of the first zone and the number of symbols comprised in the first zone are identically set in the uplink transmission period for all BSs, the location and size of the first zone are identical in all BSs.

[60] The aforementioned embodiment of the present invention discloses that the zone allocating means 104 to determine whether or not there is the spurious emission allocates the first zone to the region including the final symbol duration of the uplink transmission period. As mentioned above, in case of the normal uplink transmission period, the first zone is allocated to the three symbol durations. Thus, a modified embodiment of the present invention may use a sounding zone to decrease the number of symbols used to determine whether or not there is the spurious emission.

[61] The sounding zone is a region defined with one or more symbol durations, wherein the sounding zone indicates an allocated region to which a sounding signal is transmitted by the mobile station. In this case, the BS determines a channel state between the BS and the mobile station through the use of sounding signal.

[62] For this, the BS 100 according to one embodiment of the present invention may further include the symbol-ratio changing means 105.

[63] The symbol-ratio changing means 105 increases the number of symbols for the uplink transmission period by changing a symbol ratio of downlink transmission period to uplink transmission period in the BS frame, whereby the sounding zone for determining whether or not there is the spurious emission can be allocated to the uplink transmission period without a waste of symbol.

[64] For example, if one symbol is required for allocation of the sounding zone, the symbol ratio to άλvnlink transmission period to uplink transmission period in the normal BS frame is 27:15. When the symbol-ratio changing means 106 receives the command to determine whether or not there is the spurious emission, the symbol-ratio changing means 106 can increase the number of symbols for the uplink transmission period by one symbol through a transitory change in symbol ratio of downlink transmission period to uplink transmission period, that is, from 27:15 to 26:16.

[65] Thereafter, the zone allocating means 104 allocates the sounding zone, which is provided to determine whether or not there is the spurious emission, to one symbol- duration of the uplink transmission period. At this time, since the zone allocated to determine whether or not there is the spurious emission has no data received therein, sounding command information elements (hereinafter, referred to as "sounding command E") for the corresponding sounding zone are not generated so that the mobile station does not transmit the sounding signal.

[66] In one embodiment of the present invention, whether or not there is the spurious emission through the allocation of sounding zone may be included in the command to determine whether or not there is the spurious emission and may be transmitted to the BS. In this case, the command to determine whether or not there is the spurious emission may include information related with whether or not the sounding zone is allocated, the symbol offset of the sounding zone, and the number of symbols comprised in the sounding zone.

[67] As mentioned above, both the symbol offset of the zone to be allocated to determine whether or not there is the spurious emission and the number of symbols comprised in the corresponding zone should be identically set in all BSs. In this respect, the symbol ratio of άλvnlink transmission period to uplink transmission period should be identically changed in all BSs.

[68] The data-burst allocating means 106 allocates the data bursts into the uplink transmission period. As mentioned above, the data-burst allocating means 106 does not allocate the data bursts into the first zone, whereby no data is received in the first zone.

[69] The N level measuring means 108 measures the N level in the first zone in the uplink transmission period of the BS 100, and transmits the measured N level to the NMS 120. At this time, the measured N level may be transmitted to the NMS 120 through the EMS 110.

[70] At this time, the N level indicates an estimated value of average interference and noise power per carrier measured in the BS, wherein a unit of the N level is decibel(dB).

[71] The N level of the first zone (hereinafter, referred to as "first N level") measured by the N level measuring means 108 is used to determine whether there is the spurious emission in the BS 100 by the NMS 120.

[72] In one embodiment of the present invention, the N level measuring means 108 can measure the N level in the other regions excluding the first zone, as well as the first zone in the uplink transmission period of the BS, and transmit the measured N levels to the NMS 120. Hereinafter, the N level measured in the other regions excluding the first zone will be referred to as a second N level.

[73] The EMS 110 operates together with the BS 100 and the NMS 120 for management of the BS 100. In the first embodiment of the present invention, the EMS 110 generates the configuration file including the information related with the timing for determining whether or not there is the spurious emission, and then transmits the generated configuration file to the BS 100; or transmits the commands to determine whether or not there is the spurious emission to the BS 100. In this case, as mentioned above, the command to determine whether or not there is the spurious emission includes the symbol offset of the first zone and the number of symbols comprised in the first zone.

[74] Also, the EMS 110 transmits the first and second N levels measured by the respective BSs to the NMS 120.

[75] The NMS 120 manages the whole network applied with the wireless communication system according to the present invention. In the first embodiment of the present invention, the NMS 120 generates the command to determine whether or not there is the spurious emission, and transmits the generated command to the BS 100 through the EMS 110; or the NSM 120 determines whether or not there is the spurious emission in the BS 100 through the use of first and second N levels transmitted from the BS 100.

[76] In one embodiment of the present invention, if the first N level measured in the first zone in the uplink transmission period of the BS is transmitted from the N level measuring means 108, the NMS 120 determines whether or not the received first N level is more than a first reference value. If the first N level is more than the first reference value, it is determined that there is the spurious emission in the BS 100.

[77] In a modified embodiment of the present invention, if the first N level measured in the first zone in the uplink transmission period of the BS is transmitted from the N level measuring means 108, the NMS 120 may determine whether or not there is the spurious emission in BS 100 by comparing the first N level transmitted from the BS 100 with the first N levels transmitted from the other BSs.

[78] For example, if a difference between the first N level transmitted from the BS 100 and the average of the first N levels transmitted from the other BSs is more than a second reference value, it is determined that there is the spurious emission in the BS 100.

[79] In another embodiment of the present invention, if the first N level measured in the first zone in the uplink transmission period of the BS is transmitted from the N level measuring means 108, the NMS 120 may determine whether or not there is the spurious emission in BS 100 by comparing the received first N level with the prior first N level of the BS 100, wherein the prior first N level is stored in the NMS 120. If the received first N level is different from the prior first N level of the BS 100, the NMS 120 determines that there is the spurious emission in the BS 100. For this, whenever receiving the first N level from the BS 100, the NMS 120 stores the received first N level in a predetermined storing region (not shown).

[80] In another embodiment of the present invention, if the N level measuring means 108 transmits the first N level measured in the first zone in the uplink transmission period of the BS together with the second N level measured in the other regions excluding the first zone, the NMS 120 determines whether or not a difference between the first N level and the second N level is less than a third reference value. If the difference between the first N level and the second N level is less than the third reference value, the NMS 120 determines that there is the spurious emission in the BS 100.

[81] A method for determining whether or not there is the spurious emission in the wireless communication system according to the present invention will be explained with reference to FIG. 4.

[82] First, the BS receives the command to determine whether or not there is the spurious emission from the NSM or EMS in step of S400. At this time, as mentioned above, the command may be transmitted while being included in the configuration file provided by the EMS, or may be directly transmitted from the NMS through the EMS. The command may include the symbol offset of the zone to be allocated to determine whether or not there is the spurious emission, and the number of symbols comprised in the corresponding zone.

[83] Then, the BS generates a schedule for determining whether or not there is the spurious emission according to the command in step of S410.

[84] On reaching the timing for determining whether or not there is the spurious emission according to the generated schedule, the BS allocates the first zone for determining whether or not there is the spurious emission to the predetermined region of the uplink transmission period using information included in the command in step of S420. As mentioned above, the first zone is allocated to the region including the final symbol duration in the uplink transmission period, preferably.

[85] Thereafter, the BS generates the BS frame so as to allocate the data bursts to the other data regions excluding the first zone in the uplink transmission period in step of S425.

[86] Next, the BS measures the first N level in the first zone in the uplink transmission period of the BS frame in step of S430. In one embodiment of the present invention, the N level can be measured in the other regions excluding the first zone, as well as in the first zone in the uplink transmission period.

[87] Hereinafter, for convenience of explanation, the N level measured in the other regions excluding the first zone in the uplink transmission period of the BS frame will be referred to as the second N level.

[88] When the BS transmits the measured first and/or second N level to the NMS through the EMS in step of S440, the NMS determines whether or not there is the spurious emission in the BS through the use of first and/or second N level in step of S450.

[89] In one embodiment of the present invention, if the first N level is transmitted from the BS, the NMS can determine whether or not there is the spurious emission in the BS by determining whether or not the received first N level is more than the first referen ce value, whether or not the difference between the first N level transmitted from the BS and the average of the first N levels transmitted from the other BSs is more than the second reference value, or whether or not the received first N level is different from the priory-stored first N level of the BS, wherein the priory-stored first N level is stored in the NMS.

[90] In case the first and second N levels are transmitted together from the BS, the NMS can determine that there is the spurious emission in the BS when the difference between the first N level and the second N level is less than the third reference value.

[91] The aforementioned embodiment of the present invention discloses that the zone for determining whether or not there is the spurious emission is additionally allocated to the uplink transmission period, wherein the data bursts are not allocated into the additional zone so as to determine whether or not there is the spurious emission. However, the modified embodiment of the present invention can determine whether or not there is the spurious emission through the use of soundng zone.

[92] For this, the number of symbols comprised in the uplink transmission period is increased by changing the symbol ratio of άλvnlink transmission period to uplink transmission period of the BS. Then, the soundng zones are allocated to the regions correspondng to the increased number of symbols, whereby the soundng zones are used to determine whether or not there is the spurious emission.

[93] At this time, since the data should not be received in the zone for determining whether or not there is the spurious emission, the soundng command Es for the correspondng soundng zone are not generated so that the mobile station does not transmit the soundng signal for the correspondng zone.

[94] The aforementioned first embodment of the present invention assumes that the wireless communication system is a broadband wireless communication system.

[95] The method for determining whether or not there is the spurious emission accordng to the modfied embodment of the present invention can be applicable to any system which satisfies the following condtions; all BS frames are synchronized the resource allocation is performed by the BS, and the data-receiving region is timely dvided into the plurality of regions.

[96] [Second Embodment]

[97] FIG. 5 is a block dagram schematically illustrating a wireless communication system accordng to the second embodment of the present invention, which is capable of determining whether or not there is the spurious emission.

[98] Like the wireless communication system accordng to the first embodment of the present invention, the wireless communication system accordng to the second embodment of the present invention includes a BS 500, an EMS 510, and an NMS 520.

[99] The BS 500 functions as an intermedate means for transmitting and receiving data so as to transmit the data to a mobile station (not shown) with high efficiency. The BS 500 includes various elements for performing the intermedate function related with the data receiving and transmission.

[100] Like the first embodment of the present invention, only elements to determine whether or not there is the spurious emission will be explained as follows.

[101] As shown in the figure 5, the BS 500 to be a target for determination whether or not there is the spurious emission may include a spurious -emission determining scheduler 502, an uplinkΛ±wnlink transmission period adjusting means 504, and an N-level measuring means 506. [102] First, a function of the spurious-emission determining scheduler 502 in the wireless communication system according to the second embodiment of the present invention is identical to that of the spurious-emission determining scheduler 102 in the wireless communication system according to the first embodiment of the present invention, whereby a detailed explanation for the function of the spurious-emission determining scheduler 502 according to the second embodiment of the present invention will be omitted.

[103] On reaching a timing for determining whether or not there is the spurious emission, the timing determined by the spurious-emission determining scheduler 502, the uplink/ dawnlink transmission period adjusting means 504 adjusts a ratio of a άλvnlink transmission period to an uplink transmission period, such that a Transmit/Receive Transition Gap (hereinafter, referred to as "TTG" of frames of neighboring BSs is included in the uplink transmission period of the BS 500.

[104] At this time, the TTG is a protection-region positioned between the downlink transmission period and the uplink transmission period in one frame. Since all BSs included in the wireless communication system are synchronized to the time, all BSs do not receive and transmit the data for the TTG.

[105] For the TTG, each BS does not transmit any data. Accordingly, if a signal is detected for the TTG in the BS 500 to be the target for determination whether or not there is the spurious emission, this signal is determined as the spurious emission.

[106] In case of the BS 500 to be the target for determination whether or not there is the spurious emission, the BS 500 includes the TTG of neighboring BS frame in the uplink transmission period of the BS 500, whereby the BS 500 can determine whether or not there is the spurious emission in the TTG of the neighboring BS frame.

[107] In one embodiment of the present invention, the uplinkΛ±wnlink transmission period adjusting means 504 can adjust a ratio of the downlink transmission period to the uplink transmission period by adjusting a symbol ratio of the downlink transmission period to the uplink transmission period.

[108] In case of the normal broadband wireless communication system, one frame is comprised of 42 symbols, wherein 27 symbols are allocated to the downlink transmission period, and 15 symbols are allocated to the uplink transmission period. In the wireless communication system according to the present invention, the TTG of the neighboring BS frame may be included in the uplink transmission period of the BS by changing the number of symbols allocated to the downlink and uplink transmission periods. [109] FIG. 6 illustrates the exemplary frame wherein the number of symbols allocated to the cbwnlink and uplink transmission periods is adjusted so that the TTG of the neighboring BS frame is included in the uplink transmission period of the BS to be the target for determination whether or not there is the spurious emission.

[110] Based on the BS arrangement of FIG. 1, FIG. 6(a) illustrates a frame structure of the BS "A" which is received in the BS "C"; FIG. 6(b) illustrates a frame structure of the BS "B", which is received in the BS "C"; and FIG. 6(c) illustrates a frame structure of the BS "C" to be the target for determination whether or not there is the spurious emission.

[I l l] As shown in FIG. 6, according as the number of symbols allocated to the downlink transmission period in the frame of the BS "C" is decreased, and the number of symbols allocated to the uplink transmission period is increased; the uplink transmission period in the frame of the BS "C" is prior to the uplink transmission period in the frame of the BSs "A" and "B" Thus, the TTG 610 in the frame of the neighboring BSs "A" and "B" is included in the uplink transmission period 600 in the frame of the BS "C".

[112] Referring one again to FIG. 5, the N level measuring means 506 measures the N level in the uplink transmission period of the frame of the BS 500, and transmits the measured N level to the NMS 520.

[113] Except that the N level measuring means 506 transmits the N level, measured in the TTG 610 of the neighboring BS frame in the uplink transmission period 600 as shown in FIG. 6(c), to the NMS 520; or transmits the N levels, respectively measured in the TTG 610 of the neighboring BS frame or measured in the remaining region 620 excluding the TTG in the uplink transmission period 600, to the NMS 520, a function of the N level measuring means 506 according to the second embodiment of the present invention is identical to that of the N level measuring means 108 according to the first embodiment of the present invention, whereby a detail explanation for the function of the N level measuring means 506 will be omitted.

[114] The NMS 520 generally manages the whole network applied with the wireless communication system. In the second embodiment of the present invention, the NMS 520 may generate a command to determine whether or not there is the spurious emission, and may transmit the generated command to the BS 500 through the EMS 510; or may determine whether or not there is the spurious emission in the BS 500 through the use of N level transmitted from the BS 500.

[115] The NMS 520 in the wireless communication system according to the second embodiment of the present invention is similar to the NMS 120 in the wireless communication system according to the first embodiment of the present invention. The NMS 520 in the wireless communication system according to the second embodiment of the present invention can determine whether or not there is the spurious emission in the BS 500 by determining whether or not the N level measured in the TTG of the neighboring BS frame included in the uplink transmission period is more than a first reference value; determining whether or not a difference between an average of N levels transmitted from the other BSs and the N level measured in the TTG of the neighboring BS frame included in the uplink transmission period of the BS is more than a second reference value; comparing the transmitted N level measured in the TTG of the neighboring BS frame included in the uplink transmission period of the BS with a prior N level of the BS 500, the prior N level stored in the NMS 520; or determining whether or not a difference between the N level measured in the TTG of the neighboring BS frame included in the uplink transmission period of the BS and an N level measured in the remaining duration excluding the TTG is less than a third reference value.

[116] The aforementioned embodiment of the present invention discloses that the N level measuring means 506 measures the N level in the TTG of the neighboring BS frame included in the uplink transmission period. However, in order to measure a more precious N level, a modified embodiment of the present invention discloses the BS 500 including the zone allocating means 508, whereby a zone can be allocated to a slot duration including the TTG of the neighboring BS frame in the uplink transmission period.

[117] The TTG is not the symbol duration. According as the zone is allocated to the slot duration including the TTG, and the N level is measured in the corresponding zone, whereby it enables the more precious measurement of the N level.

[118] In more detail, as shown in FIG. 7, the zone allocating means508 allocates an additional zone 640 to the slot duration including the TTG 610 of the neighboring BS frame in the uplink transmission period 600 through the use of zone switch. In one embodiment of the present invention, the zone may be allocated to one slot duration. In a modified embodiment of the present invention, the zone may be allocated to one or more slot durations.

[119] For convenience of explanation, the zone allocated to the slot duration including the TTG 610 of the neighboring BS frame will be referred to as a first zone 640, and another zone which is differentiated from the first zone 640 will be referred to as a second zone 650.

[120] In this case, the N level measuring means 506 transmits an N level measured in the first zone 640 to the NMS 520. Then, the NMS 520 can determine whether or not there is the spurious emission in the BS 500 by determining whether or not the N level measured in the first zone 640 is more than the first reference value, determining whether or not the N level measured in the first zone 640 is different from the previously-measured N level, or determining whether or not a difference between the N level measured in the first zone 640 and an average of N levels measured in the other BSs is more than the second reference value.

[121] In the meantime, the N level measuring means 506 measures the respective N levels in the first and second zones 640 and 650, and then transmits the measured N levels to the NMS 520. Then, the NMS 520 can determine whether or not there is the spurious emission in the BS 500 by determining whether or not a difference between the N level measured in the first zone 640 and the N level measured in the second zone 650 is less than the third reference value.

[122] The aforementioned embodiment of the present invention assumed that the neighboring BS frames are received in the BS to be the target for determination whether or not there is the spurious emission without a propagation delay. However, as shown in FIG. 8, the virtual wireless communication system shows that the frames of the neighboring BSs "A" and "B" may be received in the BS "C" to be the target for determination whether or not there is the spurious emission with the propagation delay.

[123] In this case, the dawnlink data of the neighboring BSs can be detected in the TTG of the neighboring BS frames included in the uplink transmission period of the BS to be the target for determination whether or not there is the spurious emission.

[124] Accordingly, if the N level is measured in the entire TTG of the neighboring BS frame included in the uplink transmission period of the frame of the BS, the delayed downlink data of the neighboring BSs can be mistakenly determined as the spurious emission.

[125] In consideration for the propagation delay, the N level measuring means 506 can measure the N level in the late period of the TTG of the neighboring BS frame included in the uplink transmission period of the BS. This is because that there is no propagation delay of data in the late period of the TTG, even though the downlink data of the neighboring BSs is delayed due to the propagation delay. For example, supposing that the total TTG is 87.2μs. In this case, the N level is measured within a period starting from a point corresponding to 75% of the TTG to 87.2μs . [126] At this time, the N level measuring means 506 can determine an appropriate duration to determine the N level in the TTG of the frame of the neighboring BSs in consideration for the propagation delay among the BSs, as expressed in the following math-figure 1.

[127] [Equation 1]

[128]

Propagation Delay ₌ distance between B Ss ^m)

3Xl0^Sm/s

[129]

[130] In order to precisely determine whether or not there is the spurious emission even under the circumstance of propagation delay, dawnlink data bursts are not allocated to a region including the final slot duration in the dawnlink transmission period of the neighboring BSs.

[131] For this, the neighboring BSs allocate the zone to the region including the final slot duration in the dawnlink transmission period of the neighboring BS frame through the use of zone switch, and then do not allocate the downlink data bursts to the corresponding zone when allocating the άλvnlink data bursts. Preferably, the neighboring BSs allocate a dedicated pilot for the corresponding zone.

[132] This example will be explained with reference to FIG. 9. As shown in FIG. 9(a), the zone 910 is allocated to the region including the final slot duration in the άλvnlink transmission period 900 of the frame of the neighboring BS "A", and the dawnlink bursts are not allocated to the corresponding zone 910. Also, as shown in FIG. 9(b), the zone 930 is allocated to the region including the final slot duration in the downlink transmission period 920 of the frame of the neighboring BS "B", and the downlink data bursts are not allocated to the corresponding zone 930.

[133] Even though the frames of the neighboring BSs are delayed due to the propagation delay, the data is not received in the TTG of the neighboring BS frame included in the uplink transmission period of the targeted BS frame. Accordingly, it is possible to precisely determine whether or not there is the spurious emission in the targeted BS.

[134] Additionally, if the mobile stations located within a cell in which the neighboring BS is located transmit the uplink data prior to a preset time, the uplink data of the neighboring BSs can be detected within the TTG of the neighboring BS frame included in the uplink transmission period of the BS frame.

[135] As mentioned above, if the N level is measured within the entire TTG of the neighboring BS frame included in the uplink transmission period of the BS frame, the uplink data of the neighboring BSs which is transmitted prior to the preset time from the mobile station can be mistakenly determined as the spurious emission.

[136] For this, the neighboring BSs allocate the zone to the region including the first slot duration in the uplink transmission period of the neighboring BS frame through the use of zone switch, wherein the uplink bursts are not allocated into the corresponding zone when allocating the uplink bursts.

[137] If the BS 500 serves as the neighboring BS of the other BS, the zone may be allocated to the region including the final slot duration in the downlink frame by the zone allocating means 508 so as not to allocate the downlink data bursts into the corresponding zone; or the zone may be allocated to the region including the first slot duration in the uplink transmission period by the zone allocating means 508 so as not to allocate the uplink data bursts into the corresponding zone.

[138] Hereinafter, a method for determining whether or not there is the spurious emission according to the second embodiment of the present invention will be explained with reference to FIG. 10. FIG. 10 is a flow chart illustrating the method for determining whether or not there is the spurious emission according to the second embodiment of the present invention.

[139] First, the BS receives the command to determine whether or not there is the spurious emission received from the NMS or EMS in step of SlOOO. At this time, as mentioned above, the command can be transmitted while being included in the configuration file provided by the EMS, or can be directly transmitted from the NMS through the EMS.

[140] After that, the BS generates a schedule to determine whether or not there is the spurious emission according to the generated command in step of SlOlO.

[141] Next, on reaching a timing for determining whether or not there is the spurious emission according to the generated schedule, the BS adjusts the ratio of the dawnlink transmission period to the uplink transmission period so as to include the TTG of the neighboring BS frame in the uplink transmission period of the BS in step of S 1020. In one embodiment of the present invention, the ratio of the downlink transmission period to the uplink transmission period can be adjusted by the number of symbols allocated into the downlink transmission period and the number of symbols allocated into the uplink transmission period.

[142] Since the TTG is not defined based on the symbol duration, the BS can allocate the zone to the corresponding slot duration including the TTG of the neighboring BS frame in the uplink transmission period of the BS through the use of zone switch. For convenience of explanation, the zone allocated to the slot duration including the TTG is referred to as the first zone, and the zone allocated to the other slot durations excluding the slot duration including the TTG is referred to as the second zone.

[143] Next, the BS measures the N level within the uplink transmission period in the frame thereof in step of S 1030. Preferably, in consideration for the propagation delay of the neighboring BS frames, the BS measures the N level at the final point of the TTG in the frames of the neighboring BSs.

[144] In one embodiment of the present invention, when the BS measures the N level, the BS measures the N level within the TTG of the neighboring BS frame included in the uplink transmission period of the BS frame, or measures the respective N levels in the TTG of the neighboring BS frame included in the uplink transmission period and the remaining region excluding the TTG in the uplink transmission period.

[145] In the modified embodiment of the present invention, when allocating the zone to the slot duration including the TTG of the neighboring BS fame in the uplink transmission period of the BS frame, the BS can measure the N levels in the first and second zones, respectively.

[146] Thereafter, when the N level measured by the BS is transmitted to the NMS through the EMS in step of S 1040, the NMS determines whether or not there is the spurious emission in the BS through the use of N level transmitted from the BS in step of S 1050.

[147] In one embodiment of the present invention, when the BS transmits the N level measured in the TTG of the neighboring BS frame in the uplink transmission period of the BS frame, or the N level measured in the first zone to the NMS; the NMS can determine whether or not there is the spurious emission in the BS by determining whether or not the received N level is more than the first threshold value, whether or not the difference between the N level transmitted from the BS and the average of the N levels transmitted from the other BSs is more than the second reference value, and whether or not the received N level is different from the prior N level of the BS, the prior N level stored in the NMS.

[148] If receiving the N levels measured in the TTG of the neighboring BS frame in the uplink transmission period of the BS frame, and measured in the remaining region excluding the TTG of the neighboring BS frame, the NMS determines whether or not the difference between the N level measured in the TTG of the neighboring BS frame in the uplink transmission period of the BS frame and the N level measured in the remaining region excluding the TTG of the neighboring BS frame is less than the third reference value. If the difference between the N level measured in the TTG of the neighboring BS frame in the uplink transmission period of the BS frame and the N level measured in the remaining region excluding the TTG of the neighboring BS frame is less than the third reference value, it is determined that the spurious emission is received in the BS.

[149] In order to precisely determine whether or not there is the spurious emission in the BS, as mentioned above, the neighboring BSs allocate the zone to the region including the final slot duration of the cbwnlink transmission period in the frame thereof, and the cbwnlink bursts are not allocated into the corresponding zone. Preferably, the dedicated pilot is allocated into the corresponding zone.

[150] Also, the neighboring BSs allocate the zone to the region including the first slot duration in the uplink transmission period, wherein the uplink bursts are not allocated into the corresponding zone.

[151] The second embodiment of the present invention assumed that the wireless communication system corresponds to the broadband wireless communication system. However, the method for determining whether or not there is the spurious emission according to the modified embodiment of the present invention can be applicable to any system which can adjust the ratio of data-transmitting duration to data-receiving duration, without regard to the kind.

[152] The aforementioned method for determining whether or not there is the spurious emission according to the first and second embodiments of the present invention can be performed through the use of various computer means. At this time, the program to perform the method for determining whether or not there is the spurious emission is recorded in a computer-readable recording medium, for example, hard disc, CD-ROM, DVD, ROM, RAM, or flash memory.

[153] It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions.

[154] Thus, it should be understood that the aforementioned embodiments of the present invention are for purpose of illustration, and are not to be constructed as limitations of the invention. It is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

[155]

Claims

[1] A method for determining a spurious emission in a wireless communication system comprising: requesting an allocation of a first zone in an uplink transmission period in a frame of each BS, wherein data bursts are not allocated into the first zone; receiving a first N level measured in the first zone from each BS; and determining whether or not there is the spurious emission (from other BSs) is spurious emission in each BS using the first N level.

[2] The method of claim 1, wherein it is determined that there is the spurious emission in the predetermined BS when the first N level measured in the predetermined BS is more than a first reference value, the first N level measured in the predetermined BS is different from a prior first N level received from the predetermined BS, or a difference between the first N level measured in the predetermined BS and an average of N levels received from the other BSs excluding the predetermined BS is more than a second reference value in the step of determining whether or not there is the spurious emission.

[3] The method of claim 1, wherein a second N level measured in the remaining region excluding the first zone in the uplink transmission period of each BS is received with the first N level from each BS in the step of receiving the first N level, and wherein it is determined that the spurious emission is received in the predetermined BS when a difference between the first N level and the second N level received from the predetermined BS is less than a reference value in the step of determining whether or not there is the spurious emission.

[4] The method of claim 1, further comprising synchronizing the BSs before requesting the allocation of the first zone in the uplink transmission period in the frame of each BS.

[5] The method of claim 1, wherein the first zone is allocated to a region including the final symbol duration of the uplink transmission period for each BS, and a location and size of the first zone are identically set in all BSs.

[6] The method of claim 1, further comprising requesting a change in ratio of downlink transmission period to uplink transmission period in each BS so that the uplink transmission period of each BS is relatively increased more than a normal uplink transmission period by a predetermined value before requesting the allocation of the first zone in the uplink transmission period in the frame of each BS.

[7] The method of claim 1, wherein the first zone is allocated as a sounding zone in the step of requesting the allocation of the first zone in the uplink transmission period in the frame of each BS.

[8] The method of claim 7, wherein sounding command Es for the sounding zone are not generated.

[9] The method of claim 1, wherein the wireless communication system is based on at least one of EEE 802.16d/e standard, Wibro, and WiMax.

[10] A method for determining a spurious emission in a wireless communication system comprising: allocating a first zone in an uplink transmission period to determine whether or not there is the spurious emission in an uplink transmission period; generating a BS frame, wherein uplink data bursts are allocated in a data region excluding the first zone in the uplink transmission period of the BS frame; and measuring an N level in the first zone to determine whether or not there is the spurious emission.

[11] The method of claim 10, further comprising changing a ratio of downlink transmission period to uplink transmission period in each BS so that the uplink transmission period of each BS is relatively increased more than a normal uplink transmission period by a predetermined value, before allocating the first zone.

[12] The method of claim 10, wherein the first zone is allocated as a sounding zone which has no sounding command Es therefor.

[13] A method for determining a spurious emission in a wireless communication system comprising: adjusting a ratio of dawnlink transmission period to uplink transmission period in a first BS frame so as to be included a TTG of a second BS frame of a neighbor second BS in the uplink transmission period of the first BS frame if a first BS receives a command to determine whether or not there is the spurious emission; and determining whether or not there is the spurious emission using an N level of uplink transmission period measured at the first base station.

[14] The method of claim 13, wherein it is determined that there is the spurious emission in the first BS when a first N level of the first BS measured in the TTG of the second BS frame included in the uplink transmission period of the first BS frame is more than a first reference value, the first N level is different from a prior N level of the first BS, a difference between the first N level and an average of N levels of the second BSs is more than a second reference value, or a difference between the first N level and a second N level of the first BS, the second N level measured in the remaining area excluding the TTG of the second BS in the uplink transmission period of the first BS, is less than a third reference value.

[15] The method of claim 13, wherein the N level is measured in a period after a predetermined point in the TTG of the second BS frame in the step of determining whether or not there is the spurious emission.

[16] The method of claim 13, wherein a first zone, into which cbwnlink data-bursts are not allocated, is allocated to one or more slot durations including the final slot in the cbwnlink transmission period of the second BS frame.

[17] The method of claim 16, wherein a pilot allocated for the first zone is a dedicated pilot.

[18] The method of claim 13, wherein a second zone, into which uplink data-bursts are not allocated, is allocated to one or more slot durations including the first slot in the uplink transmission period of the second BS frame.

[19] The method of claim 13, wherein the step of determining whether or not there is the spurious emission comprising: allocating a third zone to at least one slot duration including the TTG of the second BS frame in the uplink transmission period of the first BS frame, and allocating a fourth zone to the remaining slot durations; measuring N levels of the first BS in the third and fourth zones, respectively; and determining that there is the spurious emission in the first BS when a difference between the N levels of the first BS measured in the third and fourth zones is less than the third reference value.

[20] The method of claim 13, wherein the adjusting the ratio of cbwnlink transmission period to uplink transmission period is performed by adjusting a symbol ratio of cbwnlink transmission period to uplink transmission period.

[21] A method for determining a spurious emission in a wireless communication system comprising: changing a ratio of cbwnlink transmission period to uplink transmission period so as to adjust a location of a TTG in a BS frame, wherein the BS frame includes the uplink transmission period, the TTG, and the downlink transmission period; and measuring an N level in the uplink period of the BS frame so as to determine whether or not there is the spurious emission.

[22] A wireless communication system comprising: a BS including a means for allocating a zone and a means for measuring an N level; and an NMS configured to determine whether or not there is the spurious emission in the BS using the N level transmitted from the BS, wherein the means for allocating the zone allocates a first zone into which uplink data-bursts are not allocated to an uplink transmission period of a BS frame so as to determine whether or not there is the spurious emission when receiving a command to determine whether or not there is the spurious emission, and the means for measuring the N level measures the N level in the first zone to transmit the measured N level to the NMS.

[23] The wireless communication system of claim 22, wherein the BS further comprises a spurious-emission determining scheduler which determines a timing for determining whether or not there is the spurious emission in response to the command to determine whether or not there is the spurious emission, and wherein the means for allocating the zone allocates the first zone to the uplink transmission period on reaching the timing determined by the spurious- emission determining scheduler.

[24] The wireless communication system of claim 22, wherein the command to determine whether or not there is the spurious emission is received from the NMS through the EMS, or is received while being included in a configuration file provided by the EMS.

[25] The wireless communication system of claim 22, wherein the command to determine whether or not there is the spurious emission includes information related with a location and size of the first zone.

[26] The wireless communication system of claim 22, wherein the NMS determines that there is the spurious emission in the BS when the N level transmitted from the BS is more than a first reference value, the N level transmitted from the BS is different from a prior N level of the BS, or a difference between the N level transmitted from the BS and an average of N levels transmitted from the other BSs excluding the BS is more than a second reference value.

[27] The wireless communication system of claim 22, wherein the means for measuring the N level additionally measures N levels in the remaining zones excluding the first zone in the uplink transmission period to transmit the additionally measured N levels to the NMS; and the NMS determines that the spurious emission is received in the BS when a difference between the N level measured in the first zone and the N level measured in the remaining zones excluding the first zone is less than a third reference value.

[28] The wireless communication system of claim 22, wherein the means for allocating the zone allocates the first zone to a region including the final symbol duration of the uplink transmission period for each BS, wherein a location and size of the first zone are identically set in all BSs.

[29] The wireless communication system of claim 22, wherein the BS further comprises a means for changing a symbol ratio of downlink transmission period to uplink transmission period so that the number of symbols of the uplink transmission period for the BS is relatively more than the number of symbols of a normal uplink transmission period.

[30] The wireless communication system of claim 22, wherein the means for allocating the zone allocates the first zone as a sounding zone without sounding command Es.

[31] A wireless communication system comprising: a BS including a means for adjusting a ratio of downlink transmission period to uplink transmission period and a means for measuring an N level; and an NMS configured to determine whether or not there is the spurious emission in the BS using the N level transmitted from the BS, wherein the means for adjusting the ratio of downlink transmission period to uplink transmission period adjusts the ratio of downlink transmission period to uplink transmission period so as to include a TTG of a neighboring BS frame in the uplink transmission period of the BS when receiving a command to determine whether or not there is the spurious emission, and the means for measuring the N level measures the N level in the uplink transmission period to transmit the measured N level to the NMS.

[32] The wireless communication system of claim 31, further comprising a spurious- emission determining scheduler configured to determine timing for determining whether or not there is the spurious emission in response to the command to determine whether or not there is the spurious emission, wherein the means for adjusting the ratio of dawnlink transmission period to uplink transmission period adjusts the ratio of downlink transmission period to uplink transmission period on reaching the timing determined by the spurious- emission determining scheduler.

[33] The wireless communication system of claim 31, wherein the means for measuring the N level measures the N level in the TTG of the neighboring BS frame included in the uplink transmission period of the BS to transmit the measured N level to the NMS; and the NMS determines that the spurious emission is received in the BS when the N level is more than a first reference value, the N level transmitted from the BS is different from a prior N level of the BS, or a difference between the N level transmitted from the BS and an average of N levels transmitted from the other BSs excluding the BS is more than a second reference value.

[34] The wireless communication system of claim 31, wherein the means for measuring the N level measures the N level at the final point of the TTG of the neighboring BS frame included in the uplink transmission period of the BS.

[35] The wireless communication system of claim 31, wherein the means for measuring the N level respectively measures the N level in the TTG of the neighboring BS frame included in the uplink transmission period of the BS and the N level in the remaining regions excluding the TTG of the neighboring BS frame in the uplink transmission period of the BS to transmit the measured N levels to the NMS; and the NMS determines that the spurious emission is received in the BS when a difference between the N level measured in the TTG of the neighboring BS frame and the N level measured in the remaining regions excluding the TTG of the neighboring BS frame is less than a third reference value.

[36] The wireless communication system of claim 31, wherein the BS further comprises a means for allocating a zone configured to allocate a third zone to at least one slot including the TTG of the neighboring BS frame in the uplink transmission period of the BS, and to allocate a fourth zone to the remaining slots, wherein the means for measuring the N level respectively measures the N levels in the third and fourth zones to transmit the N levels measured in the third and fourth zones to the NMS, the NMS determines that the spurious emission is received when a difference between the N level measured in the third zone and the N level measured in the fourth zone is less than a third reference value. [37] The wireless communication system of claim 31, wherein a first zone into which downlink data-bursts are not allocated is allocated to one or more slot durations including the final slot in the άλvnlink transmission period of the neighboring

BS frame, wherein a pilot allocated for the first zone is dedicated pilot. [38] The wireless communication system of claim 31, wherein the means for adjusting the ratio of άλvnlink transmission period to uplink transmission period adjusts a symbol ratio of downlink transmission period to uplink transmission period.