Abstract:
The present invention relates to a method for performing an interference management based on received interference signal strength, the interference management apparatus comprises a parameter setting unit configured to set up a permissible interference reference I A  of an allowable band and a percentage reference Q of an interference region, a communicating unit configured to receive information related to the received interference signal strength which is measured by at least a terminal from at least a terminal or a base station, and a comparing and determining unit configured to determine that interference excess is generated, in case that the received interference signal strength i A  of an allowable band exceeds the permissible interference reference I A . According to the present invention, it is available to figure out an interference effect which a victim receiver undergoes within a permitted region accurately.

Description:
[0001]    Priority to Korean patent application number 10-2014-0021559 filed on Feb. 24, 2014, the entire disclosure of which is incorporated by reference herein, is claimed. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to wireless communications and more particularly to a method and apparatus of radio interference estimation based on received signal strength in wireless communication systems. 
         [0004]    2. Discussion of the Related Art 
         [0005]    Currently, as the use of wireless communication services increases, so relatively does the number of wireless communication systems that are operating proximal to one another in frequency, space and time, thereby a problem of radio interference has been raised. 
         [0006]    In conventional radio interference management systems, the radio interference has been managed based on the transmission power of a transmitter.  FIG. 1  illustrates permissible standards according to an embodiment of conventional radio interference management measures. In the conventional systems, as shown in  FIG. 1 , the transmission power of a transmitter and permissible standards for respective frequency bands are compared by enacting permissible standards P A  and P B  for each frequency band. Since such a way in which a measuring equipment is directly connected to an output terminal of a transmitter, it is easy to determine whether to exceed the permissible level. Even if the signal is transmitted with the same output, the interference amount that neighboring band users are received can be changeable according to a variety of factors such as a height of a transmission radio station, characteristics of a transmission antenna, a density of a transmission radio station and so on. However, in the conventional management systems, there was a difficulty to accurately determine the degree of interference that actually influences on radio stations of the adjacent band as there was no consideration of the above factors but solely considering the output of a transmitter for each band. 
       SUMMARY OF THE INVENTION 
       [0007]    It is a principal object of the present invention is to provide a method and apparatus of radio interference estimation based on received signal strength in wireless communication systems. 
         [0008]    It is another object of the present invention is to provide a method and apparatus of interference limitation based on received interference signal strength. 
         [0009]    It is further object of the present invention is to detect an interference region and interference time based on received interference signal strength. 
         [0010]    It is still further object of the present invention is to detect a percentage of an interference region and interference time based on received interference signal strength measured from multiple mobile terminals. 
         [0011]    According to an aspect of the present invention, an interference management apparatus which performs interference management based on received interference signal strength is provided. The interference management apparatus includes a parameter setting unit configured to set up a permissible interference reference I A  of an allowable band and a percentage reference Q of an interference region, a communicating unit configured to receive information related to the received interference signal strength which is measured by at least a terminal from at least a terminal or a base station, and a comparing and determining unit configured to determine that interference excess is generated, in case that the received interference signal strength i A  of an allowable band exceeds the permissible interference reference I A . 
         [0012]    According to an aspect of the present invention, a method for managing interference performed based on received interference signal strength is provided. The method for managing interference includes setting up a permissible interference reference I A  of an allowable band and a percentage reference Q of an interference region, receiving information related to the received interference signal strength which is measured by at least a terminal from at least a terminal or a base station, and determining that interference excess is generated, in case that the received interference signal strength i A  of an allowable band for respective terminals exceeds the permissible interference reference I A . 
         [0013]    According to yet another aspect of the present invention, an interference management systems based on received interference signal strength is provided. The interference management system includes at least a terminal configured to measure at least one of the received interference signal strength i A  of an allowable band and the received interference signal strength i B  of a non-allowable band, at least a base station configured to receive at least one of the i A  and i B  from at least one of the terminals; and a interference management apparatus configured to receive at least one of the i A  and i B  from at least one of the base stations, and to compare the i A  or is with the permissible interference reference I A  of the allowable band or the permissible interference reference I B  of the non-allowable band, and to determine whether interference excess is generated for each terminal. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  illustrates permissible standards according to an embodiment of the existing radio interference management measures. 
           [0015]      FIG. 2  illustrates permissible standards according to an embodiment of radio interference management measures based on the signal strength measured by the receiving unit which the present invention is applied to. 
           [0016]      FIG. 3  illustrates an embodiment of interference management based on received interference signal strength which the present invention is applied to. 
           [0017]      FIG. 4  illustrates an interference information measuring method according to an embodiment of the present invention. 
           [0018]      FIG. 5  illustrates an embodiment of the interference percentage calculating method based on the interference management apparatus according to the present invention. 
           [0019]      FIG. 6  is a block diagram schematically illustrating the interference management apparatus according to the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0020]    The present invention suggests a radio interference management system based on received signal strength, not a radio interference management system based on the existing transmission power. The present invention is to detect an interference region and interference time that exceed permissible interference standards within a permitted region where is, operated in wireless communication systems based on the information of received signal strength which is measured from a terminal, a receiving unit, and suggests a method of calculating percentages for this. 
         [0021]    The preferred embodiment of the present invention now will be described in detail by reference to the accompanying exemplary drawings in this specification. In attaching reference numerals to elements in each drawing, it should be understood that the same reference numeral is used for the same element even if the element is shown in different drawings. In addition, in case that the detailed description for the related known elements and functions is determined to obscure the inventive concept in this specification, the redundant description for the same element will be omitted. 
         [0022]      FIG. 2  illustrates permissible standards according to an embodiment of radio interference management measures based on the signal strength measured by the receiving unit which the present invention is applied to. 
         [0023]    Referring to  FIG. 2 , a permissible interference reference for each of the bands may be determined by classifying permissible interference levels into an allowable band  200  and non-allowable band when a licensee performs communication. For example, in case of an allowable band  200 , the permissible interference reference value associated with the received interference signal strength may be determined as to I A  and in case of a non-allowable band  210 , the permissible interference reference value associated with the received interference signal strength may be determined as to I B . In this case, I A  may be a smaller value than I B . That is, the permissible interference reference value of the allowable band  200  can be set up lower than that of the non-allowable band  210 . 
         [0024]      FIG. 3  illustrates an embodiment of the interference management based on received interference signal strength which the present invention is applied to. 
         [0025]    Referring to  FIG. 3 , an interference region  310  can be detected, where the received interference signal strength i A  and i B  exceed permissible interference references I A  and I B  in comparison with a predetermined region  300 , and the percentage q of the interference region  310  against the predetermined region  300  can be calculated. Herein, the i A  is referred to as received interference signal strength of an allowable band, i B  is referred to as received interference signal strength of a non-allowable band, I A  is referred to as a permissible interference reference of an allowable band, and I B  is referred to as a permissible interference reference of a non-allowable band. Additionally, the predetermined region  300  may be represented as the whole region for which a licensee gets permission, or represented as an arbitrary predetermined region. The predetermined region  300 , for example, can be divided into m*n regions. 
         [0026]    Also, an interference time t A  can be detected, when the received interference signal strength exceeds the permissible interference references within a predetermined time T  320  in the interference region  310 , and the percentage r of the interference time t A  against the predetermined time T  320  can be calculated. 
         [0027]    If the percentage q of the interference region and the percentage r of the interference time that are calculated based on the received interference signal within the permitted region do not exceed specific references, for example, Q and R, a licensee is supposed to permit it. That is, no objection is allowed. According to the method described above, a licensee considers the received interference signal which is going to receive in the real environment and is able to perform the interference management more accurately and reasonably in the radio interference management. 
         [0028]    Most of all, in order to apply the method described above, the wireless communication systems must be enabled to make an accurate determination of the percentage q of the interference region and the percentage of the interference time r. For example, at a specific time of permitting a license, the percentage q of the interference region and the percentage of r of the interference time are calculated by using a radio signal calculation tool so as to determine whether to satisfy the specific references such as Q and R theoretically. However, in real environment, the radio signal has characteristics of changeable in real time. Therefore, the percentage q of the interference region and the percentage r of the interference time r can be calculated considering the characteristic of the radio signal above described, and determined whether the result satisfy specific references. 
         [0029]    In mobile communication systems, the percentage q of the interference region and the percentage r of the interference time r can be calculated by using the result that a terminal measures the received interference signal strength. In the mobile communication systems, it may be assumed that terminals are evenly distributed within a predetermined region as user equipments move with mobility. Otherwise it may be assumed that more terminals are positioned in a certain location with weighting. Herein, the terminal is referred to as another terms such as a user equipment UE, a mobile station MS, a user terminal UT, a subscriber station ST, a wireless device, a personal digital assistant PDA, a wireless modem, a handheld device and so on. 
         [0030]      FIG. 4  illustrates an interference information measuring method according to an embodiment of the present invention.  FIG. 4  depicts that an interference management apparatus is distinguished from a base station, but it is only for an example and the interference management apparatus may be included in a part of the base station. 
         [0031]    Referring to  FIG. 4 , the terminals  400  which are located within a permitted region forward the interference information i A  and i B  which are obtained in an allowable band and non-allowable band respectively to the interference management apparatus  440  through the base station  420 . The terminal  400  measures the interference strength i A  of the allowable band and the interference strength i B  of the non-allowable band respectively, and forwards the i A  and i B  to the base station  420  through a wireless link. 
         [0032]    The base station  420  forwards the i A  and i B  of the terminals  400  within the region where the base station itself manages to the interference management apparatus  440 . The base station  420 , in this case, may forward the location information of the terminals  400  further more to the interference management apparatus  440 . 
         [0033]    The interference management apparatus  440  collects the information of the interference strength i A  of the allowable band and the interference strength i B  of the non-allowable band which are forwarded by multiple base stations  420  connected to wireless networks and by the terminal  400  connected to each of the base stations, and calculates the interference percentage based on the information above. 
         [0034]      FIG. 5  illustrates an embodiment of the interference percentage calculating method based on the interference management apparatus according to the present invention. 
         [0035]    Referring to  FIG. 5 , the interference management apparatus sets up a permissible interference reference I A  of an allowable band, a permissible interference reference I B  of a non-allowable band, a percentage reference Q of an interference region, and a percentage reference R of interference time (step, S 500 ). 
         [0036]    The interference management apparatus receives the information related to the received interference signal strength which is measured by terminals from at least one base station (step, S 510 ). Herein, the information related to the received interference signal strength includes the received interference signal strength i A  of an allowable band and where the received interference signal strength i B  of a non-allowable band for each of the terminals. In addition, the information related to the received interference signal strength may further include the location information of the corresponding terminals. 
         [0037]    The interference management apparatus determines whether to exceed the permissible interference reference (step, S 520 ). The interference management apparatus may compare between I A , I B , i A  and i B , and in case of i A &gt;I A  or i B &gt;I B , may determine that the i A  and i B  exceed the permissible interference reference. 
         [0038]    If the received interference signal strength exceeds the permissible interference reference in step, S 520 , the interference management apparatus calculates the percentage q of an interference region (step, S 530 ). As an example, assuming that locations of the terminals are uniformly distributed, the interference management apparatus may directly calculate the percentage of the interference region based on the ratio of the number of terminals of which the received interference signal strength exceed the permissible interference reference against all terminals. As another example, the interference management apparatus may detect the location of terminals that exceed the permissible interference reference within a predetermined region (for example, a permitted region or service region) in further considering the location information of the terminals, and calculate the percentage of the interference region based on it. 
         [0039]    The interference management apparatus compares the percentage q of the interference region calculated above and the percentage reference Q of an interference region which is set up beforehand, and determines whether the percentage q of the interference region exceeds the reference value Q (step, S 540 ). 
         [0040]    Further, if the received interference signal strength exceeds the permissible interference reference in step, S 520 , the interference management apparatus detects an interference time t A  (step, S 550 ). The interference management apparatus may detect the interference time t A  when the received interference signal strength exceeds the permissible interference reference for a predetermined time T. 
         [0041]    The interference management apparatus calculates the interference time percentage r based on the interference time t A  detected above (step, S 550 ). For example, the interference management apparatus may detect t A  for the respective terminals which exceed the permissible interference reference, and based on this, calculate the percentage of the interference time for the respective terminals this and collect the result so as to calculate the percentage of the interference time. As another example, the interference management apparatus may detect the interference time t A  when the received interference signal strength exceeds the permissible interference reference for a predetermined time. T, and based on this, may calculate the percentage of the interference time for the respective interference regions. 
         [0042]    The interference management apparatus compares the percentage r of the interference time calculated above and the percentage reference R of the interference time which is set up beforehand, and determines whether the percentage r of the interference time exceeds the reference value R (step, S 570 ). 
         [0043]    In the wireless communication system in which the radio signal is changeable in real time according to the method described above, it is available to calculate the percentage of the interference region and the percentage of the interference time, also to determine whether to exceed the reference value. On the basis of this, it is available to easily determine whether the received interference signal strength satisfies the interference reference which is represented as a percentage in wireless communication systems. 
         [0044]      FIG. 6  is a block diagram schematically illustrating the interference management apparatus according to the present invention. 
         [0045]    Referring to  FIG. 6 , the interference management apparatus  600  according to the present invention includes a communicating unit  610 , parameter setting unit  620 , a comparing and determining unit  630 , and a calculating unit  640 . 
         [0046]    The communicating unit  610  performs communications with a terminal or base station. As an example, an interference management apparatus  600  may be constructed in a base station, and in this case, it is enabled to communicate directly with a terminal. As another example, in case of an interference management apparatus being constructed in a separate device, the interference management apparatus may directly communicate with a terminal without passing through any base station. 
         [0047]    The communicating unit  610  receives the information of the received interference signal strength from at least a terminal or a base station. The received interference signal strength is measured by a terminal (terminals). The information of the received interference signal strength includes the received interference signal strength i A  of an allowable band and the received interference signal strength i B  of a non-allowable band for the respective terminals. Additionally, the information related to the received interference signal strength may further include the location information of the corresponding terminals. 
         [0048]    The parameter setting unit  620  sets up the permissible interference reference I A  of an allowable band, permissible interference reference I B  of a non-allowable band, percentage reference Q of the interference region, and percentage reference R of the interference time. 
         [0049]    The comparing and determining unit  630  determines whether to exceed the permissible interference reference based on the information related to the interference signal strength. The comparing and determining unit  630  compares between I A , I B , i A  and i B , and may determine that the i A  and i B  exceed the permissible interference reference in case of i A &gt;I A  or i B &gt;I B . 
         [0050]    Additionally, based on the location information of the corresponding terminal, the comparing and determining unit  630  may determine the interference region where a terminal is located, which exceeds the permissible interference reference. 
         [0051]    Furthermore, the comparing and determining unit  630  may detect the interference time t A  when the received interference signal strength exceeds the permissible reference within a predetermined time T. 
         [0052]    The calculating unit  640  calculates the percentage q of the interference region. As an example, assuming that locations of the terminals are uniformly distributed, the calculating unit  640  may directly calculate the percentage of the interference region based on the ratio of the number of terminals of which the received interference signal strength exceed the permissible interference reference against all terminals. As another example, the calculating unit  640  may detect the location of terminals that exceed the permissible interference reference within a predetermined region (for example, a permitted region or service region) in further considering the location information of the terminals, and calculate the percentage of the interference region based on it. 
         [0053]    In addition, the calculating unit  640  calculates the interference time percentage r based on the interference time t A  detected above. For example, the interference management apparatus may detect t A  for the respective terminals which exceed the permissible interference reference, and based on this, calculate the percentage of the interference time for the respective terminals this and collect the result so as to calculate the percentage of the interference time. As another example, the interference management apparatus may detect the interference time t A  when the received interference signal strength exceeds the permissible interference reference for a predetermined time T, and based on this, may calculate the percentage of the interference time for the respective interference regions. 
         [0054]    The comparing and determining unit  630  may compare the percentage q of the interference region calculated above and the percentage reference Q of an interference region which is set up beforehand, and determine whether the percentage q of the interference region exceeds the reference value Q. The comparing and determining unit  630  may compare the percentage r of the interference time calculated above and the percentage reference R of the interference time which is set up beforehand, and determine whether the percentage r of the interference time exceeds the reference value R. 
         [0055]    So far, the present invention has been described by reference to the drawings and the embodiments as an example, and it should be understood by those skilled in the art, however, that the present invention can be modified or changed, in various ways without departing from the technical principles and scope. Accordingly, the embodiment disclosed in the present invention is not intended to limit the scope of the inventive concept of the present invention, but to describe, and the scope of the inventive concept of the present invention is not limited to the embodiment. The scope of the present invention should be interpreted by the claims below, and it should be interpreted that all inventive concept within the equivalent scope is included in the scope of the present invention.