Abstract:
An apparatus for wireless relaying comprises: a transmission unit for generating a wireless signal; an amplification unit for amplifying and outputting the wireless signal; a conversion unit for converting the wireless signal into a digital signal; and an adjustment unit for adjusting the amplification ratio of the amplifying unit so that the difference between an output level value of the digital signal and a predetermined target power is lower than a predetermined numerical value.

Description:
RELATED APPLICATIONS 
       [0001]    This is a national stage application of PCT/KR2011/0077196 filed on Oct. 19, 2011 which claims priority from Korean Patent Application No. 10-2011-0033790, filed on Apr. 12, 2012, in the Korean Intellectual Property Office, the disclosures of which are hereby incorporated herein in their entirety by reference. 
     
    
     BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The present invention relates to an apparatus for wireless relaying (access point) that provides a near field communication service. 
         [0004]    2. Description of the Related Art 
         [0005]    With the popularity of mobile communication devices, such as smartphones, notebook computers, etc., apparatuses for wireless relaying have been increasingly installed at more locations than ever in order to provide near field communication services. There can be a plural number of apparatuses for wireless relaying installed and operated in an arbitrary area, and a user terminal can select one of the plural apparatuses for wireless relaying to use a near field communication service. 
         [0006]    However, when there are plural apparatuses for wireless relaying within a particular area, interference may occur in a wireless signal transmitted by each apparatus for wireless relaying. Accordingly, the apparatuses for wireless relaying should be installed at respective locations for which the coverage area of each apparatus for wireless relaying is considered. However, since the coverage area of the common apparatus for wireless relaying is inconsistent, there may be areas where a service by the apparatus for wireless relaying is available, or the coverage areas may be excessively overlapped to cause interferences, or some particular area may need to have an excessive number of apparatuses for wireless relaying installed therein. 
       SUMMARY 
       [0007]    The present invention provides an apparatus for wireless relaying that can stabilize a current corresponding to a wireless signal. 
         [0008]    An aspect of the present invention features an apparatus for wireless relaying, including: a transmission unit configured to generate a wireless signal; an amplification unit configured to amplify and output the wireless signal; a conversion unit configured to convert the wireless signal to a digital signal; and an adjustment unit configured to adjust an amplification ratio of the amplification unit so that a difference between an output level value of the digital signal and a predetermined target power becomes smaller than a predetermined numerical value. 
         [0009]    Another aspect of the present invention features an apparatus for wireless relaying, including: a transmission unit configured to generate a wireless signal; an amplification unit configured to amplify and output the wireless signal; a conversion unit configured to convert the wireless signal to a digital signal; and an adjustment unit configured to adjust an amplification ratio of the amplification unit, if an average of an output level value of the digital signal and a predetermined target power is not equal to the target power, until the average becomes equal to the target power. 
         [0010]    Yet another aspect of the present invention features a method for an apparatus for wireless relaying to relay a user terminal by use of a wireless signal, including: generating a wireless signal; amplifying and outputting the wireless signal; converting the wireless signal to a digital signal; and adjusting an amplification ratio so that a difference between an output level value of the digital signal and a predetermined target power becomes smaller than a predetermined numerical value. 
         [0011]    Still another aspect of the present invention features a method for an apparatus for wireless relaying to relay a user terminal by use of a wireless signal, comprising: generating a wireless signal; amplifying and outputting the wireless signal; converting the wireless signal to a digital signal; and adjusting an amplification ratio, if an average of an output level value of the digital signal and a predetermined target power is not equal to the target power, until the average becomes equal to the target power. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a block diagram briefly illustrating an apparatus for wireless relaying. 
           [0013]      FIG. 2  is a flow diagram illustrating the operations for adjusting an output level of a wireless signal by an apparatus for wireless relaying in accordance with a first exemplary embodiment. 
           [0014]      FIG. 3  is a flow diagram illustrating the operations for adjusting an output level of a wireless signal by an apparatus for wireless relaying in accordance with a second exemplary embodiment. 
           [0015]      FIG. 4  shows an example of coverage of a wireless signal provided by the apparatus for wireless relaying. 
       
    
    
     DETAILED DESCRIPTION 
       [0016]    Since there can be a variety of permutations and embodiments of the present invention, certain embodiments will be illustrated and described with reference to the accompanying drawings. This, however, is by no means to restrict the present invention to certain embodiments, and shall be construed as including all permutations, equivalents and substitutes covered by the ideas and scope of the present invention. 
         [0017]    When one element is described to “transmit” or “send” a signal to another element, it shall be construed as transmitting or sending the signal to the other element by being directly connected to the other element but also as possibly transmitting or sending the signal by way of another element in between, unless disclosed otherwise. 
         [0018]      FIG. 1  is a block diagram briefly illustrating an apparatus for wireless relaying. 
         [0019]    Referring to  FIG. 1 , the apparatus of wireless relaying includes a communication controller  110 , a wireless transmitter  120 , an amplifier  130 , a coupler  140 , a converter  150  and an adjuster  160 . 
         [0020]    The communication controller  110  relays data transmission between each user terminal connected to the apparatus for wireless relaying and devices connected to the apparatus for wireless relaying. For example, the communication controller  110  can transmit data received through a communication network connected with the apparatus for wireless relaying to the wireless transmitter  120  to have the data transmitted to a user terminal through a wireless signal. 
         [0021]    The wireless transmitter  120  generates a wireless signal including the data received from the communication controller  110 . The wireless transmitter  120  transmits the generated wireless signal to the amplifier  130 . 
         [0022]    The amplifier  130  amplifies the wireless signal and outputs the amplified wireless signal through an antenna. The amplifier  130  can adjust the power corresponding to the wireless signal by adjusting a gain. Here, the gain of the amplifier  130  can be adjusted by the adjuster  160 , and the amplifier  130  varies the amplification ratio according to the adjusted gain and outputs the amplified wireless signal according to the adjusted amplification ratio. 
         [0023]    The coupler  140  detects the wireless signal outputted from the amplifier  130  and transmits the wireless signal to the converter  150 . 
         [0024]    The converter  150  converts the wireless signal, which is an analog signal, to a digital signal. The converter  150  transmits the digital signal to the adjuster  160 . 
         [0025]    The adjuster  160  computes a gain based on an output level value of the digital signal. For instance, the adjuster  160  computes the gain according to a difference between the output level value of the digital signal (hence referred to as “measured power” hereinafter) and an output level value of the wireless signal to be finally outputted by the apparatus for wireless relaying (hence referred to as “target power” hereinafter). The steps for computing the gain by the adjuster  160  will be described later in detail with reference to  FIGS. 2 and 3 . The adjuster  160  adjusts the amplification ratio of the amplifier  130  based on the computed gain. 
         [0026]      FIG. 2  is a flow diagram illustrating the steps for adjusting an output level of a wireless signal by the apparatus for wireless relaying in accordance with a first embodiment of the present invention. 
         [0027]    In step  210 , the adjuster  160  receives the digital signal from the converter  150  and computes the measured power, which is the output level value of the digital signal. 
         [0028]    In step  220 , the adjuster  160  computes an offset, which is a value having the measured power deducted from the target power. 
         [0029]    In step  230 , the adjuster  160  determines whether an absolute value of the offset is smaller than a predetermined numerical value. 
         [0030]    In step  230 , if the absolute value of the offset is smaller than or equal to the predetermined numerical value, the adjuster  160  terminates the adjusting of the output level of the wireless signal. 
         [0031]    If the absolute value of the offset is greater than the predetermined numerical value in step  230 , the adjuster  160  determines, in step  240 , whether the offset is 0 or greater. 
         [0032]    If the offset is greater than or equal to 0 in step  240 , the adjuster  160  computes, in step  250 , an adjusted power by reducing the measured power by the predetermined numerical value. 
         [0033]    If the offset is smaller than  0  in step  240 , the adjuster  160  computes, in step  260 , the adjusted power by increasing the measured power by the predetermined numerical value. 
         [0034]    In step  270 , the adjuster  160  determines whether a difference between the target power and the adjusted power is smaller than or equal to a predetermined numerical value. 
         [0035]    If the difference between the target power and the adjusted power is greater than the predetermined numerical value in step  270 , the adjuster  160  sets the offset according to the target power and the adjusted power, and repeats the steps, from step  240 . 
         [0036]    If the difference between the target power and the adjusted power is smaller than or equal to the predetermined numerical value in step  270 , the adjuster  160  computes a gain corresponding to the adjusted power, controls the amplifier  130  according to the computed gain, and adjusts the output level of the wireless signal in step  280 . 
         [0037]      FIG. 3  is a flow diagram illustrating the steps for adjusting an output level of a wireless signal by the apparatus for wireless relaying in accordance with a second embodiment of the present invention. 
         [0038]    Referring to  FIG. 3 , in step  310 , the adjuster  160  receives a digital signal from the converter  150  and computes a measured power, which is an output level value of the digital signal. 
         [0039]    In step  320 , the adjuster  160  computes an average of a target power and the measured power. With respect to the description of the remaining operations in  FIG. 3 , the average of target power and the measured power will be referred to simply as the “average”. 
         [0040]    In step  330 , the adjuster  160  determines whether the average computed in step  320  is the same as the target power. 
         [0041]    In step  330 , if the average is the same as the target power, the adjuster  160  terminates the output level adjusting step of the wireless signal. 
         [0042]    In step  340 , if the average is different from the target power, the adjuster  160  determines whether the average is greater than the target power. 
         [0043]    If the average is greater than the target power in step  340 , the adjuster  160  controls, in step  350 , the amplifier  130  so that the gain is reduced by a predetermined numerical value until the average becomes equal to the target power. That is, after reducing the gain by the predetermined numerical value, the adjuster  160  repeats the step of reducing the gain by the predetermined numerical value if the average is not equal to the target power. When the average becomes equal to the target power after the gain is reduced by the predetermined numerical value, the adjuster  160  terminates the output level adjusting step of the wireless signal. 
         [0044]    If the average is smaller than the target power in step  340 , the adjuster  160  controls, in step  360 , the amplifier  130  so that the gain is increased by the predetermined numerical value until the average becomes equal to the target power. That is, after increasing the gain by the predetermined numerical value, the adjuster  160  repeats the step of increasing the gain by the predetermined numerical value if the average is not equal to the target power. When the average becomes equal to the target power after the gain is increased by the predetermined numerical value, the adjuster  160  terminates the output level adjusting step of the wireless signal. 
         [0045]    Hereinafter, an effect provided by outputting the wireless signal with certain coverage by the apparatus for wireless relaying will be described.  FIG. 4  shows an example of coverage of the wireless signal provided by the apparatus for wireless relaying. 
         [0046]    In case the coverage area of the apparatus for wireless relaying is inconsistent, the user terminal needs to attempt to access the apparatus for wireless relaying repeatedly, pursuant to variations of the coverage area. For instance, if it is assumed that coverage of an apparatus  405  for wireless relaying changes between first coverage  410  and second coverage  420 , a user terminal  430  can be disconnected from the apparatus  405  for wireless relaying when the coverage of the apparatus  405  for wireless relaying extends only to the edge of first coverage  410  and can be connected with the apparatus  405  for wireless relaying when the coverage of the apparatus  405  for wireless relaying is up to the second coverage  420 . When the coverage of the apparatus  405  for wireless relaying is inconsistent, as described above, the user terminal  430  that is located near boundaries of the coverage may continually disconnect and access the apparatus  405 , making it difficult to continuously provide a near field communication service. 
         [0047]    Moreover, since the coverage needs to be considered, the apparatus  405  for wireless relaying needs to be installed based on the first coverage  410 . Accordingly, the coverage of the apparatus  405  for wireless relaying overlaps with other areas because there are instances where the coverage actually changes to the second coverage  420 . 
         [0048]    Therefore, by making the coverage consistent, the apparatus for wireless relaying in accordance with the first embodiment and the second embodiment of the present invention can prevent the user terminal from repeatedly disconnecting from and accessing the apparatus for wireless relaying, and the locations for installing the apparatus for wireless relaying can be readily configured. 
         [0049]    Through the above-described steps, the apparatus for wireless relaying in accordance with the first and second embodiments of the present invention can provide a wireless signal having consistent coverage, preventing the user terminal from attempting to repeatedly access the apparatus for wireless relaying due to variations of the coverage. 
         [0050]    Hitherto, the present invention has been described in accordance with certain embodiments, but there are many other embodiments in the claims of the present invention in addition to the embodiments described above. Anyone having ordinary skill in the art to which the present invention pertains shall be able to understand that the present invention can be embodied in modified forms without departing from the essential features of the present invention. Accordingly, the disclosed embodiments shall be understood in illustrative views, not in restrictive views. The scope of the present invention shall be defined by the appended claims, not by the above description, and any and all differences within the equivalent scope shall be understood to be included in the present invention.