JP2010258514A - Indoor mobile communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an indoor mobile communication system which can make radio wave intensity equal to or lower than a reference value of a radio wave protection guide, while suppressing the number of antennas necessary for forming a communication area, when a radio base station is to be installed indoors. <P>SOLUTION: A free-access floor 30 is prepared indoors in a boundary of a sitting room 10, which forms an under floor space S isolated from the sitting room 10, and a floor unit with a slit 310 is prepared, through which radio waves are radiated from monopole antennas 221 to 224 prepared in an air gap formed in the free access floor 30. The free-access floor 30 is constituted of a material which reflects the radio waves. The monopole antennas 221 to 224 are installed in the under floor space S so that the free-access floor 30 is located between the antennas and the sitting room 10. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an indoor mobile communication system that uses a radio base station including an antenna unit and uses a predetermined indoor area as a communication area.

  In a mobile communication system such as a cellular phone system, a method of installing a radio base station under a free access floor or behind a ceiling is widely used to enable indoor communication such as in a building.

  In this way, when installing the radio base station indoors, in order to facilitate the installation work of the antenna unit composed of the radio base station and one or more antennas, the radio base station is placed on the back side (under the floor) of the floor panel. A method is known in which a station is attached and a planar antenna is attached to the surface side (floor upper side) of the floor panel (for example, Patent Document 1).

Japanese Patent Laying-Open No. 2005-27213 (page 3-4, FIG. 1-2)

  By the way, regarding the protection of human bodies in the use of radio waves, radio frequency protection guidelines have been provided by the Administration (Telecom Technical Council Advisory No. 38 “Human Protection Guidelines in the Use of Radio Waves” (consultation on June 27, 1988)) ).

  However, in the above-described conventional method, the “radio wave” distance between the antenna and the human body, that is, the coupling loss between the antenna and the human body is small and may exceed the reference value of the radio wave protection guidelines.

  In order to solve such a problem, it is necessary to reduce the effective radiation power of the radio wave radiated from the antenna. For this reason, in order to form a communication area having the same size as before the reduction of the effective radiation power, it is necessary to increase the number of antennas.

  Therefore, the present invention has been made in view of such circumstances, and in the case of installing a wireless base station indoors, the number of antennas necessary for forming a communication area is suppressed, and the intensity of the radio wave is protected. It is an object of the present invention to provide an indoor mobile communication system that can be reduced to a reference value or less of a guideline.

  In order to solve the problems described above, the present invention has the following features. First, the first feature of the present invention is that a wireless base station (wireless base station 200) including an antenna unit (monopole antennas 221 to 224) is used, and indoor movement is performed using a predetermined indoor area (room 10) as a communication area. In the communication system, a separation part (free access floor 30) that forms another space (underfloor space S) isolated from the communication area is provided at a boundary of the communication area in the indoor part. A radio wave transmission part (for example, a floor part 310 with a slit) that is provided in the formed gap and transmits radio waves (radio wave W) radiated from the antenna part is provided, and the separation part is made of a material that reflects the radio waves. At least the antenna unit is installed in the separate space, and the antenna unit is installed so that the separation unit is located between the communication area and the antenna unit. To.

  According to such an indoor mobile communication system, the separation part made of a material that reflects radio waves is located between the antenna part and the communication area. For this reason, the radio wave radiated from the antenna unit is blocked by the separation unit and propagates to the communication area via the radio wave transmission unit provided in the gap formed in the separation unit.

  In addition, by adjusting the shape and arrangement of the radio wave transmission part, the electric field strength in the communication area can be averaged, and the average electric field intensity required for communication can be averaged. The coupling loss with the human body can be increased.

  That is, according to such an indoor mobile communication system, when a wireless base station is installed indoors, the number of antennas necessary for forming a communication area is suppressed, and the intensity of radio waves radiated from the antenna is determined as a wave protection guideline. Can be below the standard value.

  The second feature of the present invention relates to the first feature of the present invention, and is summarized in that a slit (for example, a slit 311) is formed in the radio wave transmitting portion.

  A third feature of the present invention is related to the first feature of the present invention, and is characterized in that it includes a fading generation unit that generates fading in the radio wave.

  A fourth feature of the present invention relates to the first feature of the present invention, and is provided with a first radio wave reflector (for example, a metal reflector 211) made of a material that reflects the radio wave, and the first radio wave reflector. The gist is that the portion is provided between the separation portion and the antenna portion. In the fourth feature of the present invention, a material that reflects radio waves to the end (upper end 221te) and the end (lower end 221be) side (for example, the floor) of the antenna unit on the side of the separation portion is used. A configured radio wave reflector (metal reflector 240) may be provided, and the antenna unit may be sandwiched between the radio wave reflector and the first radio wave reflector.

  A fifth feature of the present invention relates to the first feature of the present invention, and comprises at least a pair of second radio wave reflectors (metal reflectors 215, 230) made of a material that reflects the radio wave, The second radio wave reflection part is provided so as to face each other in the separate space, and the antenna part is provided between the pair of second radio wave reflection parts.

  A sixth feature of the present invention is related to the first feature of the present invention, and is summarized in that the radio wave transmitting portion is made of a material that transmits the radio wave.

  A seventh feature of the present invention relates to the first feature of the present invention, and is summarized in that the separation portion is made of metal.

  An eighth feature of the present invention relates to the second feature of the present invention, and is summarized in that the slit has a length corresponding to the wavelength of the radio wave.

  A ninth feature of the present invention relates to the eighth feature of the present invention, and is summarized in that a length along the longitudinal direction of the slit (slit length L) is substantially half of the wavelength.

  A tenth feature of the present invention relates to the eighth feature or the ninth feature of the present invention, wherein the radio wave transmitting portion has a first slit (for example, a slit 311) and substantially the same as the first slit. The gist is that a vertical second slit (slit 312) is formed.

  An eleventh feature of the present invention relates to the eighth or ninth feature of the present invention, wherein the radio wave transmitting portion is formed with a slit group (for example, a slit group 319A) constituted by a plurality of the slits. The gist is that the slits constituting the slit group are formed at equal intervals.

  A twelfth feature of the present invention is according to the eleventh feature of the present invention, wherein the radio wave transmitting portion is formed with a plurality of slit groups, and constitutes one of the slit groups (for example, the slit group 319A). The gist of the present invention is that the position of the slit to be different from the position of the slit constituting the adjacent slit group (slit group 319B).

  A thirteenth feature of the present invention is according to the eighth feature of the present invention, wherein the radio wave transmitting portion has movable parts (movable panel 320b, rotating panel 320c) movable in a predetermined direction, and the slit is The gist is that it is formed on the movable part.

  A fourteenth feature of the present invention relates to the third feature of the present invention, wherein the fading generation unit is interposed between the antenna unit and the radio base station, and the signal output from the radio base station is included. The gist is that it is configured by a fading simulator (for example, fading simulator 202A) that artificially generates fading.

  A fifteenth feature of the present invention is according to the third feature of the present invention, wherein the antenna unit includes a directional antenna having a directivity (horn-type antenna unit 252), and the fading generation unit includes the directivity. The gist of the present invention is that the antenna rotation mechanism (motor 251) rotates the antenna.

  A sixteenth feature of the present invention relates to the third feature of the present invention, wherein the fading generation unit is installed in the separate space, and a radio wave that rotates a radio wave scatterer (radio wave scatterer 261) that scatters the radio wave. It is constituted by a scatterer rotating mechanism (motor 262), and the radio wave scatterer rotating mechanism is arranged in the vicinity of the antenna unit.

  A seventeenth feature of the present invention is according to the third feature of the present invention, wherein the second radio wave reflecting portion is installed so as to face a radio wave radiated from the antenna portion, and reciprocates the antenna portion in a predetermined section. The gist is to provide an antenna moving mechanism (drive device 271) to be operated.

  An eighteenth feature of the present invention is according to the third feature of the present invention, wherein the second radio wave reflecting portion is disposed so as to face the radio wave radiated from the antenna portion, and the second radio wave reflecting portion is set to be predetermined. The gist is to include a reflection unit moving mechanism (drive device 281) that reciprocates in the section.

  A nineteenth feature of the present invention relates to the first feature of the present invention, wherein the antenna section includes a transmitting antenna (transmitting monopole antenna 221V) and a receiving antenna (receiving planar antenna 290), and the receiving antenna Is provided on the surface of the separation portion on the communication area side.

  According to the features of the present invention, when a radio base station is installed indoors, an indoor mobile communication system capable of reducing the intensity of radio waves below the reference value of the radio wave protection guideline while suppressing the number of antennas necessary for forming a communication area. Can be provided.

It is the whole indoor schematic block diagram in which the mobile communication system which concerns on embodiment of this invention is installed. It is a top view of the building floor part which shows the installation state of the mobile communication system installed in the underfloor space which concerns on embodiment of this invention. FIG. 3 is a side view of the underfloor space along the line F3-F3 shown in FIG. It is a figure which shows the structural example of the floor part with a slit of the basic type which concerns on embodiment of this invention. It is a figure which shows the structural example of the floor part with a slit of a multiband corresponding | compatible type which concerns on embodiment of this invention. It is a figure which shows the structural example of the floor part with a level stable type slit with which it concerns on embodiment of this invention. It is a figure which shows the structural example of the floor part with a level adjustment type | mold slit which concerns on embodiment of this invention. It is a top view of the building floor part in which the directional antenna which concerns on embodiment of this invention is installed. It is a side view of a part of the underfloor space in which the directional antenna according to the embodiment of the present invention is installed. It is a side view of a part of the underfloor space in which the radio wave scattering device according to the embodiment of the present invention is installed. It is a side view of a part of the underfloor space in which the directional antenna and the metal reflector according to the embodiment of the present invention are installed. It is a figure which shows the structural example of the transmitting antenna which concerns on the example of a change of this invention, and a receiving antenna.

  Next, an embodiment of the present invention will be described. Specifically, (1) the overall schematic configuration of the mobile communication system, (2) the structure of the radio wave transmission section (floor section with slits), and (3) the configuration example of the fading generation section will be described.

  In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and ratios of dimensions are different from actual ones.

  Accordingly, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

(1) Overall Schematic Configuration of Mobile Communication System First, an overall schematic configuration of the mobile communication system according to the present embodiment will be described with reference to FIGS.

(1.1) Indoor configuration where mobile communication system is installed FIG. 1 is an overall schematic configuration diagram of an indoor where a mobile communication system according to the present embodiment is installed. The mobile communication system according to the present embodiment, specifically, the radio base station 200 uses a room 10 such as an office, that is, a predetermined indoor area as a communication area. In this embodiment, the radio base station 200 performs radio communication with the radio communication terminals 100A and 100B in accordance with the third generation mobile phone system using the CDMA method.

  The living room 10 has a double floor structure and is provided with a free access floor 30. Specifically, the free access floor 30 is provided above the building floor 20 that is a floor of a building such as a building (not shown). In the present embodiment, the building floor 20 is formed of a building structural material including concrete.

  By providing the free access floor 30, an underfloor space S (separate space) isolated from the communication area is formed in the living room 10 (indoor). In the present embodiment, the free access floor 30 constitutes a separation portion provided at the boundary of the communication area.

  In the underfloor space S, a radio base station 200 is installed. The radio base station 200 includes monopole antennas 221 to 224 (antenna units), and the monopole antennas 221 to 224 (antenna units) are also installed in the underfloor space S. The monopole antennas 221 to 224 are installed such that the free access floor 30 is located between the living room 10 (communication area).

  The free access floor 30 is made of a material that reflects the radio wave W (not shown in FIG. 1, see FIG. 3) radiated from the monopole antennas 221 to 224. Specifically, the free access floor 30 is made of a plate material of a predetermined size made of metal (steel).

  In the present embodiment, a metal reflector 211 is provided between the monopole antenna 221 and the free access floor 30. The metal reflector 211 is made of a material that reflects the radio wave W. Similarly, a metal reflector 214 is provided between the monopole antenna 224 and the free access floor 30. In the present embodiment, the metal reflectors 211 and 214 constitute a first radio wave reflector.

  The metal reflector 211 (214) is provided immediately above the monopole antenna 221 (224). Further, the metal reflector 211 prevents the radio wave W radiated from the monopole antenna 221 from propagating directly to the living room 10 through the free access floor 30. In the present embodiment, since the free access floor 30 is made of a material (metal) that reflects radio waves, the metal reflector 211 (214) is not necessarily provided. The metal reflectors 211 and 214 are preferably provided immediately above the monopole antenna 221 (224) when the free access floor 30 is made of a material that transmits radio waves (such as synthetic resin).

  A space (not shown) is formed in the free access floor 30, and floor portions 310, 330, and 350 with slits are provided in the space. Slits 311 and 312 (not shown in FIG. 1, refer to FIG. 2) are formed in the floor portion 310 with slits. The floor portions 330 and 350 with slits also have the same structure as the floor portion 310 with slits.

  The floor portions 310, 330, and 350 with slits are provided so as to avoid directly above the monopole antennas 221 to 224. Thereby, it is possible to prevent the intensity of the radio wave W from becoming too high immediately above the monopole antennas 221 to 224.

  Similarly to the free access floor 30, the floor portions 310, 330 and 350 with slits are made of a plate material of a predetermined size made of metal (steel). Since slits 311 and 312 are formed in floor portion 310 (330, 350) with slits, radio wave W radiated from the antenna portion passes through slits 311 and 312. In the present embodiment, the floor portion 310 (330, 350) with slits constitutes a radio wave transmitting portion that transmits the radio wave W.

(1.2) Installation State of Mobile Communication System FIG. 2 is a plan view of the building floor 20 showing the installation state of the mobile communication system installed in the underfloor space S. FIG. 3 is a side view of the underfloor space S along the line F3-F3 shown in FIG. In this embodiment, the indoor mobile communication system includes a radio base station 200, metal reflectors 211 and 214, and floor portions 310, 330, and 350 with slits.

  The radio base station 200 includes a base station main body 201, fading simulators 202A to 202C, and monopole antennas 221 to 224.

  The base station main body 201 is configured by an RF block that executes processing in a radio frequency band, a digital modulation / demodulation block, a baseband signal processing block, and the like. Base station body 201 is connected to fading simulators 202A to 202C.

  The fading simulators 202A to 202C are installed in the underfloor space S. Fading simulators 202A to 202C cause fading in radio wave W (see FIG. 3). In the present embodiment, the fading simulators 202A to 202C constitute a fading generation unit.

  Fading simulator 202A and monopole antenna 221 are connected by a feeder line 221a. Similarly, fading simulator 202A and monopole antenna 223 are connected by feeder line 223a.

  Further, fading simulator 202B and monopole antenna 222 are connected by a feeder line 222a. Fading simulator 202C and monopole antenna 224 are connected by a feeder line 224a.

  Fading simulator 202A is interposed between monopole antennas 221 and 222 and base station body 201. The fading simulator 202A generates pseudo-fading, that is, a radio wave W whose amplitude fluctuates with time in a signal output from the base station main body 201.

  In this embodiment, since three fading simulators, specifically, fading simulators 202A to 202C emit radio waves W with non-constant amplitudes, they are reflected by radio waves W and structures emitted from the respective antennas. By combining the received radio wave W, a state is produced in which the radio wave W varies in amplitude and polarization with time in a certain place. The fading simulators 202B and 202C also have the same function as the fading simulator 202A.

  More specifically, the radio wave W radiated from the monopole antennas 221 to 224 to the underfloor space S is formed by a building floor 20 formed by a structural material for building including concrete and a metal plate. Reflection with the free access floor 30 is repeated. When reflection is repeated between the building floor 20 and the free access floor 30, the radio wave W becomes a standing wave and exists in the underfloor space S.

  The radio wave W radiated from the monopole antennas 221 to 224 passes through the slits 311 and 312 formed in the floor portion 310 with the slit and propagates to the living room 10. Similarly, the radio wave W propagates to the living room 10 through slits (not shown) formed in the floor portions 330 and 330 with slits (see arrows in FIG. 3).

  The floor portions 310, 330, and 350 with slits are used to adjust the electric field strength in the living room 10 to be substantially constant. Specifically, a floor portion with slits in which slits 311 and 312 are formed like a floor portion with slit 310 is combined with an ordinary free access floor portion (a metal plate of a predetermined size) in which no slit is formed. Thus, the electric field intensity in the living room 10 is adjusted to be substantially constant. In the living room 10, a lot of floor portions with slits are arranged in places where the electric field intensity due to the radio wave W is weak.

  In addition, as shown in FIG. 3, the metal reflector 215 and the metal reflector 230 may be installed in the underfloor space S. The metal reflector 215 and the metal reflector 230 are plates that are made of a material that reflects radio waves, specifically, metal (for example, steel). In the present embodiment, the metal reflector 215 and the metal reflector 230 constitute a pair of second radio wave reflectors.

  The metal reflector 215 and the metal reflector 230 are provided to face each other in the underfloor space S. The monopole antennas 221 and 223 are provided between the metal reflector 215 and the metal reflector 230. The metal reflector 215 and the metal reflector 230 are provided along the longitudinal direction of the monopole antennas 221 and 223, that is, in a state of standing in the vertical direction.

  The metal reflector 215 and the metal reflector 230 promote the reflection of the radio wave W and generate a strong resonance space in the underfloor space S. Further, the reflection of the radio wave W is promoted by the metal reflector 215 and the metal reflector 230, thereby suppressing the leaked radio wave W from the underfloor space S to the outside of the room 10 (building). Radio wave W (standing wave) with fading can be generated stably.

  The metal reflector 240 is provided on the building floor 20 (floor surface). The metal reflector 240 is made of a material (such as metal) that reflects radio waves, and suppresses the radio wave W from being absorbed by the building floor 20. The metal reflector 240 is used in pairs with the metal reflector 211. The metal reflector 211 is provided on the end (upper end 221te) side of the monopole antenna 221 on the free access floor 30 side, and the metal reflector 240 is on the end (lower end 221be) side (floor) opposite to the upper end 221te. Surface). That is, the metal reflector 211 and the metal reflector 240 are arranged so as to sandwich the monopole antenna 221.

  The metal reflector 211 and the metal reflector 240 promote the reflection of the radio wave W and generate a strong resonance space in the underfloor space S. In addition, as for the metal reflecting plate 240, you may want to form an unevenness | corrugation in the surface. In this case, the metal reflection plate 240 also has a function of a diffusion plate that diffuses radio waves.

(2) Structure of radio wave transmission part (floor part with slit) Next, with reference to FIG. 4A to FIG. 7B, the floor part 310 with a slit and other components constituting the radio wave transmission part in this embodiment An example of the structure of the floor portion with slits will be described. Specifically, the structure of the floor portion with slits of (1) basic type, (2) multiband compatible type, (3) level stable type, and (4) level adjustable type will be described.

(2.1) Structural example 1 (basic type)
4 (a) to 4 (c) show examples of the structure of the basic floor portion with slits. Fig.4 (a) is a top view of the floor part 310 with a slit shown in FIGS. 1-3. As shown to Fig.4 (a), the slit 311 and the slit 312 are formed in the floor part 310 with a slit. The slit 311 and the slit 312 are formed along the outer edge of the floor portion 310 with the slit. In the present embodiment, a member made of a material that transmits radio waves, specifically, a resin (synthetic resin) member is fitted into the slit 311 and the slit 312. The resin member does not necessarily have to be fitted, and the slit 311 and the slit 312 may be covered with a carpet or the like.

  The slit 311 and the slit 312 have a length corresponding to the wavelength λ of the radio wave W. Specifically, the slit length L, which is the length along the longitudinal direction of the slit 311 and the slit 312, is approximately half of the wavelength λ. Further, the wavelength λ varies depending on the dielectric constant of the material of the slit 311 and the slit 312.

  The slit 312 is formed so as to be substantially perpendicular to the slit 311. In the present embodiment, the slit 311 constitutes a first slit. Further, the slit 312 constitutes a second slit.

  FIG. 4B is a plan view of the floor portion 310 </ b> A having a slit, where the slit is formed at a position different from the floor portion 310 with the slit. As shown in FIG.4 (b), the slit 313 and the slit 314 are formed in the floor part 310A with a slit. The slit 313 is formed along a diagonal line (not shown) of the floor portion 310 </ b> A with a slit that is rectangular in plan view. The slit 314 is formed so as to be substantially perpendicular to the slit 313. The slit 313 constitutes a first slit. Further, the slit 314 constitutes a second slit.

  A resin member is fitted into the slit 313 and the slit 314. Further, the slit lengths of the slit 313 and the slit 314 are approximately half of the wavelength λ of the radio wave W.

  FIG.4 (c) is a top view of the floor part 310B with a slit from which the shape of a slit differs from the floor parts 310 and 310A with a slit. As shown in FIG.4 (c), the cross-shaped slit 315 is formed in the floor part 310B with a slit. The slit length of the slit 315 is substantially half of the wavelength λ of the radio wave W.

  In the present embodiment, the electric field strength in the living room 10 is adjusted to be substantially constant using the floor portion with slit 310, the floor portion with slit 310A or the floor portion with slit 310B.

(2.2) Structure example 2 (Multi-band compatible type)
FIG. 5 shows an example of the structure of a multiband-compatible floor with a slit. Specifically, FIG. 5 is a plan view of a floor portion 310 </ b> C with slits that supports multiband. A slit group 316 and a slit group 317 are formed on the floor portion 310C with slits.

  The slit group 316 includes slits 316a to 316c. The slit 316a has the shortest slit length among the slits constituting the slit group 316, and corresponds to the high frequency band. The slit 316c has the longest slit length among the slits constituting the slit group 316, and corresponds to the low frequency band. The slit 316b has an intermediate slit length between the slit 316a and the slit 316c, and corresponds to a frequency band corresponding to the slit 316a and an intermediate frequency band corresponding to the slit 316c.

  The slit group 317 includes slits 317a to 317c. The slits 317a to 317c have the same shape as the slits 316a to 316c. The slits 317a to 317c are formed so as to be substantially perpendicular to the slits 316a to 316c. Resin members are fitted into the slits 316a to 316c and the slits 317a to 317c. The slit lengths of the slits 316a to 316c and the slits 317a to 317c are substantially half of the wavelength λ of the radio wave W.

(2.3) Structure example 3 (level stable type)
FIG. 6 shows a structural example of a level stable type floor portion with slits. Specifically, FIG. 6 is a plan view of a level-stabilized floor portion 310D with slits. A large number of slits 318 are formed in the floor portion 310D with slits. A resin member is fitted into the slit 318. Further, the slit length of the slit 318 is substantially half of the wavelength λ of the radio wave W.

  Specifically, a slit group 319A configured by a plurality of slits 318 is formed on the floor portion 310D with slits. Similarly, a slit group 319 </ b> B, a slit group 319 </ b> C, and the like configured by a plurality of slits 318 are formed on the floor portion 310 </ b> D with slits.

  The four slits 318 constituting the slit group 319A are formed at equal intervals (1/4 to 1/8 of the wavelength is a guide). The slits 318 constituting the slit group 319B and the slit group 319C are also formed at equal intervals.

  By forming the slits 318 at equal intervals, it is possible to increase the possibility that the position of any slit 318 constituting the slit group overlaps with the abdomen of the standing wave. For this reason, the electric field intensity in the living room 10 can be stabilized by the radio wave W radiated to the living room 10 through the slit 318.

  Further, the positions of the slits 318 constituting the slit group 319A are different from the positions of the slits 318 constituting the adjacent slit group 319B. Furthermore, the slits 318 constituting the slit group 319A are formed so as to be substantially perpendicular to the slits 318 constituting the slit group 319C. For this reason, since the possibility that the position of any of the slits 318 formed in the floor portion 310D with slits overlaps with the position of the abdominal portion of the standing wave, the electric field strength in the living room 10 can be stabilized. it can.

(2.4) Structure example 4 (level adjustment type)
FIGS. 7A and 7B show examples of the structure of a level-adjustable floor with slits. Specifically, FIG. 7A is a plan view of a level-adjustable floor portion 310E with slits. FIG.7 (b) is sectional drawing of the floor part 310E with a slit along the F7b-F7b line | wire shown to Fig.7 (a).

  As shown in FIGS. 7A and 7B, the floor portion 310 E with slits is attached to a gap (not shown) formed in the free access floor 30. The floor portion 310E with a slit is constituted by a resin cover 320a, a moving panel 320b, and a rotating panel 320c.

  The resin cover 320a is fitted into a gap formed in the free access floor 30. The resin cover covers the upper surface of the movable panel 320b.

  The movable panel 320b is movably held by the free access floor 30. For example, by forming a hook-like portion (not shown) that engages with an engaging groove (not shown) formed on the free access floor 30, the moving panel 320 b can be moved by the free access floor 30. Hold.

  The rotating panel 320c is held by the moving panel 320b. The rotating panel 320c can rotate on the moving panel 320b. In the present embodiment, the moving panel 320b and the rotating panel 320c constitute a movable part that can move in a predetermined direction.

  A slit 320d is formed in the rotary panel 320c. The slit length of the slit 320d is substantially half of the wavelength λ of the radio wave W.

  The moving panel 320b and the rotating panel 320c are moved or rotated manually, but may be driven using a driving device (not shown) configured by a motor, a gear, or the like. An electric field sensor may be provided in the resin cover 320a.

  Further, when the movable panel 320b and the rotating panel 320c are driven using the driving device, the driving panel 320b and the rotating panel 320c can be driven according to a predetermined algorithm. For example, the rotating panel 320c is driven in a time zone with low communication traffic, such as at night. Specifically, the slit 320d formed in the rotating panel 320c is rotated, and the electric field intensity measured using the electric field sensor is maximized. The position of the panel 320c (or the moving panel 320b) can be detected. The operation is preferably executed once a day or at an arbitrary timing.

  Further, the slit 320d may be rotated in a time zone with a small amount of communication traffic such as at night, and the relationship between the rotation angle of the rotary panel 320c and the electric field strength may be stored in the memory. In an operation time zone such as daytime, based on the relationship stored in the memory, the rotary panel 320c is positioned so that the electric field intensity of the living room 10 due to the radio wave W radiated through the slit 320d is constant.

  Furthermore, a driving device that drives the moving panel 320b and the rotating panel 320c may be linked to the radio base station 200. Specifically, from the wireless communication terminal to the wireless base station that the electric field intensity of the radio wave W measured in a specific wireless communication terminal (for example, the wireless communication terminal 100A, see FIG. 1) has reached the set maximum value. 200, the radio base station 200 transmits an instruction to move the position of the slit 320d to the driving device that drives the moving panel 320b and the rotating panel 320c. Based on the instruction, the driving device moves the position of the slit 320d to reduce the electric field strength of the living room 10.

  Conversely, when the electric field strength of the radio wave W measured in a specific wireless communication terminal (for example, the wireless communication terminal 100A) is lower than a predetermined value, the wireless base station 200 moves the moving panel 320b and the rotating panel 320c. An instruction to move the position of the slit 320d is transmitted to the driving device to be driven. Based on the instruction, the driving device moves the position of the slit 320d to increase the electric field strength of the living room 10.

(3) Configuration Example of Fading Generation Unit Next, a configuration example of the fading generation unit will be described with reference to FIGS. As described above, in this embodiment, fading is generated in the radio wave W using the fading simulators 202A to 202C.

  Here, another configuration example that can be used in place of fading simulators 202A to 202C and that can cause fading of radio wave W will be described. Specifically, a configuration example using (1) a directional antenna with a rotation function, (2) a radio wave scattering device, (3) a directional antenna or a metal reflector is described.

(3.1) Directional Antenna with Rotation Function FIG. 8 is a plan view of the building floor 20 on which the horn antenna 250 is installed. FIG. 9 is a side view of a part of the underfloor space S in which the horn antenna 250 is installed.

  Horn antenna 250 is connected to base station body 201 through feeder line 256. The horn antenna 250 has directivity.

  The horn antenna 250 includes a motor 251, a horn type antenna unit 252, an RF branching unit 253, waveguides 254 a and 254 b, and a radio wave radiating element 255. In the present embodiment, the horn type antenna unit 252 constitutes a directional antenna.

  The motor 251 rotates the horn antenna 250, specifically, the horn type antenna unit 252 and the RF branching device 253. In the present embodiment, the motor 251 constitutes an antenna rotation mechanism.

  The horn type antenna unit 252 is formed by two horn type antenna elements. An RF branching device 253 is connected to the horn type antenna unit 252. The radio wave W radiated from the horn type antenna unit 252 rotated by the motor 251 changes in intensity in proportion to the rotation of the horn type antenna unit 252 with respect to a certain direction. The radio wave W radiated from the horn type antenna unit 252 interferes with the radio wave W reflected by a structure such as the metal reflector 215 and the metal reflector 230, and the amplitude of the radio wave W fluctuates in a short time at a certain place. Fading is performed. The radio wave W passes through the slit formed in the floor portion 310 (330, 350) with the slit and propagates to the living room 10.

  The RF branching device 253 branches the radio wave transmitted from the base station main body 201 to the waveguide space by the waveguides 254 a and 254 b via the radio wave radiating element 255 to the horn constituting the horn type antenna unit 252.

  The waveguide 254a and the waveguide 254b are circular waveguides. In this embodiment, in order to avoid physical distortion between the rotating horn type antenna unit 252 and the fixed radio wave radiation element 255 or lower, a double structure is formed by the waveguide 254a and the waveguide 254b, and the waveguide is guided. The tube 254b is fixed, and the waveguide 254a is rotated by the motor 251 together with the horn type antenna unit 252 and the RF branching device 253.

  The radio wave radiating element 255 is connected to the feeder line 256 and transmits a signal in the radio frequency band transmitted from the base station main body 201 to the waveguide 254a and the waveguide 254b.

  The normal horn type antenna is provided with a radio wave radiating element in the horn. However, in the horn antenna 250, the radio wave radiating element 255 is provided near the base station main body 201 outside the horn, and the horn has a radio wave radiating element. The radiating element 255 is not provided.

(3.2) Radio Scattering Device FIG. 10 is a side view of a part of the underfloor space S in which the radio wave scattering device 260 is installed. The radio wave scattering device 260 includes a radio wave scatterer 261 and a motor 262.

  The radio wave scatterer 261 is configured by a metal plate-like member, and scatters the radio wave W radiated from the monopole antenna 221.

  The motor 262 rotates the radio wave scatterer 261. In the present embodiment, the motor 262 constitutes a radio wave scatterer rotating mechanism. The motor 262 is disposed in the vicinity of the monopole antenna 221.

  The radio wave W scattered by the radio wave scatterer 261, the radio wave W emitted from the monopole antenna 221, and the radio wave reflected by a structure such as the metal reflector 215 and the metal reflector 230 interfere with each other. In a certain place, a fading state occurs in which the amplitude of the radio wave W fluctuates in a short time. Further, the radio wave W propagates to the living room 10 through the slit formed in the floor portion 310 (330, 350) with the slit.

(3.3) Reciprocating Motion of Directional Antenna or Metal Reflector FIG. 11 is a side view of a part of the underfloor space S where the antenna 270 and the metal reflector 280 are installed.

  The antenna 270 radiates the radio wave W in a predetermined direction, specifically, in the direction of the metal reflector 280.

  The metal reflector 280 (second radio wave reflector) is installed so as to face the radio wave W radiated from the antenna 270. Specifically, a front portion (not shown) of the metal reflector 280 is installed so as to face the radio wave W.

  A driving device 281 is attached to the metal reflector 280. The drive device 281 reciprocates the metal reflector 280 in a predetermined section (see the arrow in the drawing). Specifically, the metal reflector 280 reciprocates in a section of about ¼λm when the radio wave W is a wavelength λ. In the present embodiment, the driving device 281 constitutes a reflection unit moving mechanism.

  Further, instead of reciprocating the metal reflector 280 using the driving device 281, the antenna 270 may be reciprocated in a predetermined section. In this case, a driving device 271 that reciprocates the antenna 270 is used. In the present embodiment, the driving device 271 constitutes an antenna moving mechanism.

  Due to the interference between the radio wave W radiated from the antenna 270 and the radio wave W reflected by the metal reflector 280, a specific region having a high electric field strength can be formed in the underfloor space S. Moreover, the slit formed in the floor part 310 (330, 350) with a slit is provided in the said specific area | region. Such a configuration is particularly effective when there are many obstacles that hinder the propagation of the radio wave W in the underfloor space S and it is difficult to form a standing wave with high electric field strength. In the case of this configuration example, the fading simulators 202A to 202C are not necessarily provided.

(Action / Effect)
According to the indoor mobile communication system described above, a material (metal) that reflects the radio wave W is provided between the antenna unit (for example, the monopole antennas 221 to 224) of the radio base station 200 and the living room 10 (communication area). The configured free access floor 30 is located. For this reason, the radio wave radiated from the antenna unit is blocked by the free access floor 30, and floor portions with slits (for example, floor portions 310, 330, and 350 with slits) provided in gaps formed in the free access floor 30. It propagates to the living room 10 through slits (for example, slits 311, 312) formed in.

  For this reason, the electric field strength of the living room 10 is averaged, and the coupling loss between the antenna unit and the human body can be increased. In addition, since the electric field strength of the living room 10 is averaged and the coupling loss between the antenna unit and the human body is increased, the transmission power from the antenna constituting the antenna unit can be increased.

  That is, according to such an indoor mobile communication system, when the radio base station 200 is installed indoors such as the living room 10, the number of antennas necessary for forming the communication area is suppressed, and the reference value of the radio wave protection guideline is not exceeded. The intensity of the averaged radio wave W can be formed in the living room 10.

  According to the indoor mobile communication system described above, the radio wave W radiated from the antenna unit propagates to the living room 10 through the slit formed in the floor portion with the slit, so that the radio wave W radiated from the antenna unit is Leakage in the direction of other radio base stations installed outside 10 is small, and interference given to other radio base stations can be reduced. In particular, when the antenna unit of the radio base station 200 is installed in the vicinity of the window 40 (see FIG. 1) provided in the living room 10, the antenna unit can be seen from the outside of the living room 10 and is installed outside the living room 10. It is easy to give strong interference to other radio base stations. The indoor mobile communication system described above contributes greatly to reducing such interference.

  According to the indoor mobile communication system described above, by preparing a plate for the free access floor 30 to which antennas (for example, monopole antennas 221 to 224) are attached, compared with the case where it is installed on the ceiling or the like, The number of man-hours required for installing the indoor mobile communication system can be greatly reduced. Furthermore, since an antenna etc. are not exposed to the living room 10, the beauty of the living room 10 is not spoiled. For this reason, it is easy to obtain the consent of the owner who provides the living room 10 for the installation of the indoor mobile communication system.

  According to the indoor mobile communication system described above, when the layout of the living room 10 is changed, the change is made by changing the position of the floor with slits without moving the plate for the free access floor 30 to which the antenna is attached. A communication area suitable for the layout of the subsequent room 10 can be easily and quickly formed. For this reason, it is possible to omit applications and tests to the Administration that has jurisdiction over the construction and telecommunications associated with the antenna relocation.

  According to the indoor mobile communication system described above, fading is generated in the radio wave W in the underfloor space S. When fading is generated in the radio wave W, the radio wave W is not generated in a certain place, and a state in which the intensity and direction fluctuate with time is created. For this reason, even when any object (for example, a communication-related device or a cable) is added to the underfloor space S, it is not necessary to adjust the position (direction) of the slit formed in the floor portion with the slit. Further, it is possible to stabilize the radio wave W propagating to the living room 10 through the slit formed in the floor portion with the slit.

  According to the indoor mobile communication system described above, the metal reflector 211 (214) is provided between the free access floor 30 and the monopole antenna 221 (224). For this reason, it can prevent more reliably that the electromagnetic wave radiated | emitted from the monopole antenna 221 propagates directly to the living room 10.

  Furthermore, according to the indoor mobile communication system described above, the metal reflectors 215 and 230 promote the reflection of the radio wave W and generate a strong resonance space in the underfloor space S. Further, the reflection of the radio wave W is promoted by the metal reflector 215 and the metal reflector 230, thereby suppressing the leaked radio wave W from the underfloor space S to the outside of the room 10 (building). Radio wave W (standing wave) with fading can be generated stably.

  Further, according to the indoor mobile communication system described above, the metal reflector 211 and the metal reflector 240 sandwich the monopole antenna 221 at both the upper end 221te and the lower end 221be of the monopole antenna 221 on the free access floor 30 side. Placed in. For this reason, the metal reflector 211 and the metal reflector 240 can promote the reflection of the radio wave W and generate a strong resonance space in the underfloor space S.

(Other embodiments)
As described above, the content of the present invention has been disclosed through one embodiment of the present invention. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments will be apparent to those skilled in the art.

  For example, in the above-described embodiment of the present invention, the monopole antennas 221 to 224 are used as the transmission antenna and the reception antenna, but the transmission antenna and the reception antenna may be independent.

  FIG. 12 shows a configuration example of the transmission antenna and the reception antenna when the transmission antenna and the reception antenna are made independent. Specifically, FIG. 12 is a side view of a part of the underfloor space S in which the transmission monopole antenna 221V and the reception planar antenna 290 are installed.

  Transmission monopole antenna 221V radiates radio wave W as a transmission antenna. Reception flat antenna 290 is provided on the surface of room 10 (communication area) of free access floor 30. Transmission monopole antenna 221V and reception planar antenna 290 are connected to base station body 201.

  The reception planar antenna 290 is a patch antenna having a free access floor 30 made of a metal plate material as a shield structure. The reception planar antenna 290 is preferably installed in the vicinity of the passage of the living room 10 in order to improve the reception sensitivity of the base station main body 201. If the reception sensitivity of the base station main body 201 is improved, the required transmission power of the radio communication terminals 100A and 100B is suppressed, and interference given to the radio base station outside the building (building) including the living room 10 can be reduced.

  In addition, when a radio base station (hereinafter, “existing radio base station”) is already installed on the ceiling of the living room 10, the antenna of the existing radio base station is used as a reception antenna instead of using the reception plane antenna 290. The transmission monopole antenna 221V installed in the underfloor space S may be used as the transmission antenna. According to such a configuration, interference from the radio base station 200 to the radio base station outside the building (building) including the living room 10 can be reduced.

  In the embodiment described above, the horn antenna 250 is used as the directional antenna, but another directional antenna may be used instead of the horn antenna 250.

  In the above-described embodiment, the metal reflector 211 (214) is provided between the monopole antenna 221 (224) and the free access floor 30, but the metal reflector 211 (214) is provided. It does not have to be.

  Furthermore, in the above-described embodiment, fading is generated in the radio wave W, but fading may not necessarily occur in the radio wave W. In this case, the intensity of the radio wave W in the living room 10 may be automatically adjusted to be increased by the antenna 270 and the metal reflector 280 (see FIG. 11) or the level-adjusted slit floor (see FIG. 7). . Moreover, you may adjust so that the intensity | strength of the electromagnetic wave W of the living room 10 may become strong by adjusting the position of the slit (refer FIG.4 and FIG.5) formed in the floor part with a slit manually.

  However, readjustment is required when the arrangement relationship of the structures in the underfloor space S is changed, such as when there are more structures in the underfloor space S. On the other hand, the advantage of the fading simulator is that there is no need to adjust the slit position. If the radio wave W intensity is weak at a specific location in the living room 10, the slit is increased, and if the radio wave W intensity is strong, the slit is decreased. The intensity of the radio wave W in the living room 10 can be adjusted more easily.

  In the embodiment described above, the underfloor space S is used. However, the mobile communication system described above may be configured using a space behind the ceiling.

  In the embodiment described above, the third generation mobile phone system using the CDMA system has been described as an example. However, the wireless communication system to which the present invention can be applied is not limited to the third generation mobile phone system.

  As described above, the present invention naturally includes various embodiments that are not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

DESCRIPTION OF SYMBOLS 10 ... Living room, 20 ... Building floor part, 30 ... Free access floor, 40 ... Window, 100A, 100B ... Wireless communication terminal, 200 ... Wireless base station, 201 ... Base station main part, 202A-202C ... Fading simulator, 211 , 214, 215 ... Metal reflector, 221-224 ... Monopole antenna, 221a-224a ... Feed line, 221V ... Transmission monopole antenna, 230, 240 ... Metal reflector, 250 ... Horn antenna, 251 ... Motor, 252 ... Horn type antenna unit, 253... RF splitter, 254a, 254b, waveguide, 255, radio wave radiating element, 256, feeding line, 260, radio wave scattering device, 261, radio wave scatterer, 262, motor, 270, directivity Antenna, 271 ... Drive device, 280 ... Metal reflector, 281 ... Drive device, 290 ... Receiving plane Antenna, 310, 310A to 310E, 330, 350 ... floor with slit, 311 to 315 ... slit, 316 ... slit group, 316a to 316c ... slit, 317 ... slit group, 317a to 317c, 318 ... slit, 319A to 319C ... slit group, 320a ... resin cover, 320b ... moving panel, 320c ... rotating panel, 320d ... slit, L ... slit length, S ... under-floor space, W ... radio wave

Claims (5)

An indoor mobile communication system using a wireless base station including an antenna unit and having a predetermined indoor area as a communication area,
In the indoor, a separation part that forms another space isolated from the communication area is provided at the boundary of the communication area,
A radio wave transmission part that is provided in a gap formed in the separation part and transmits radio waves radiated from the antenna part;
The separation portion is made of a material that reflects the radio waves,
At least the antenna unit is installed in the separate space,
The antenna unit is an indoor mobile communication system that is installed such that the separation unit is located between the antenna unit and the communication area.   The indoor mobile communication system according to claim 1, wherein a slit is formed in the radio wave transmitting portion.   The indoor mobile communication system according to claim 1, further comprising a fading generation unit that generates fading in the radio wave. Comprising a first radio wave reflecting portion made of a material that reflects the radio wave;
The indoor mobile communication system according to claim 1, wherein the first radio wave reflection unit is provided between the separation unit and the antenna unit. A second radio wave reflecting portion configured of a material that reflects the radio wave;
2. The indoor mobile communication system according to claim 1, wherein the second radio wave reflection unit is provided on a surface of the separate space where the separation unit is not formed.

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