JP2012165057A - Mimo radio system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a MIMO radio system which realizes a uniform communication speed over the whole region of a communication area.SOLUTION: A MIMO radio system 10 receives and transmits data by using multiple antennas 12 connecting with a radio body 11. In the MIMO radio system 10, the multiple antennas 12 includes one or more leakage coaxial cables 13 and a normal antenna 14 that is the antenna 12 excluding the leakage coaxial cables 13. The leakage coaxial cable 13 is disposed so as to enclose the normal antenna 14.

Description

  The present invention relates to a MIMO wireless system that transmits and receives data using a plurality of antennas connected to a wireless device body.

  In recent years, MIMO (Multiple Multiplex) has been developed to combine multiple antennas to increase the capacity of data transmission and reception for further speedup of wireless communication such as wireless LAN (Local Area Network), WiMAX (Worldwide Interoperability for Microwave Access), and cellular. (Multiple Output) is used.

  MIMO is a wireless communication technique for expanding communication capacity by simultaneously transmitting different data using a plurality of antennas and combining them at the time of reception. For example, if the number of antennas is two, the communication capacity can be expanded so that the number is two times and the number of antennas is three times.

  In the conventional MIMO wireless system, as shown in FIG. 4A, a wireless device 40 in which a plurality of antennas 41 are directly installed on the wireless device main body 42 is used. It is arranged in the center so that MIMO communication can be performed.

JP 2010-239544 A JP 2008-236552 A JP 2006-295433 A JP 2007-318278 A JP 2004-343402 A

  However, in the conventional MIMO radio system, as shown in FIG. 4B, there is a problem that the communication speed decreases as the terminal is farther from the radio 40 (antenna 41) even in the communication area A.

  Therefore, an object of the present invention is to provide a MIMO radio system capable of realizing a uniform communication speed over the entire communication area.

  The present invention devised to achieve this object is a MIMO wireless system that transmits and receives data using a plurality of antennas connected to a radio main body. The MIMO wireless system includes a coaxial cable and a normal antenna that is an antenna other than the leaky coaxial cable, and the leaky coaxial cable is disposed so as to surround the normal antenna.

  The normal antenna may be disposed at the center of the communication area, and the leaky coaxial cable may be disposed along the outer peripheral edge of the communication area.

  Two or more of the plurality of antennas may be constituted by leaky coaxial cables, and each of the leaky coaxial cables may be arranged so as to surround the normal antenna with different diameters.

  The wireless device main body and the plurality of antennas may be connected using a cable, and the arrangement of the wireless device main body and the arrangement of the plurality of antennas may be determined independently.

  According to the present invention, it is possible to provide a MIMO radio system capable of realizing a uniform communication speed over the entire communication area.

It is a figure which shows the MIMO radio system which concerns on the 1st Embodiment of this invention, (a) is a block diagram of a MIMO radio system, (b) is the communication speed distribution map in the horizontal surface of a MIMO radio system. It is a figure which shows the MIMO radio system which concerns on the 2nd Embodiment of this invention, (a) is a block diagram of a MIMO radio system, (b) is a communication speed distribution map in the horizontal surface of a MIMO radio system. It is a figure which shows the MIMO radio system which concerns on the 3rd Embodiment of this invention, (a) is a block diagram of a MIMO radio system, (b) is the communication speed distribution map in the horizontal surface of a MIMO radio system. It is a figure explaining the conventional MIMO radio system, (a) is a perspective view of the radio | wireless machine in a MIMO radio system, (b) is a communication speed distribution map in the horizontal surface of a MIMO radio system.

  Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a diagram illustrating a MIMO radio system according to a first preferred embodiment of the present invention, where (a) is a configuration diagram of the MIMO radio system, and (b) is a communication speed distribution in the horizontal plane of the MIMO radio system. FIG.

  As shown in FIG. 1A, a MIMO radio system 10 according to the first embodiment is a system that transmits and receives data using a plurality of antennas 12 connected to a radio main body 11. The antenna 12 includes at least one leaky coaxial cable (open coaxial cable; LCX) 13 and a normal antenna 14 that is an antenna 12 other than the leaky coaxial cable 13. The antenna is arranged so as to surround the antenna.

  The MIMO wireless system 10 is installed on the ceiling 16 of the building 15 and forms a communication area A in the building 15.

  A plurality of antennas 12 for transmitting and receiving data are connected to the wireless device main body 11. The number of antennas 12 is not particularly limited, but a plurality of antennas 12 are required to obtain a MIMO effect.

  In the present embodiment, two antennas 12 are connected to the radio device main body 11, one of them is configured by a leaky coaxial cable 13, and the other is a normal antenna (for example, a dipole installed directly on the radio device main body 11). Antenna element) 14. As the normal antenna 14, various antennas such as a slot antenna and a patch antenna can be applied.

  The radio device body 11 and the leaky coaxial cable 13 are connected using a coaxial cable 17. As a result, the arrangement of the wireless device main body 11 (normal antenna 14) and the arrangement of the leaky coaxial cable 13 are independently determined. The leaky coaxial cable 13 is configured to leak radio waves having a predetermined intensity or more over the entire length thereof.

  The leaky coaxial cable 13 and the normal antenna 14 are arranged so as to eliminate an area where the communication speed of the communication area A is low, that is, an area where the electric field strength does not reach a predetermined value. Specifically, the normal antenna 14 is disposed at the center of the communication area A to be constructed together with the wireless device main body 11, and the leaky coaxial cable 13 is disposed along the outer peripheral edge of the communication area A to be constructed. As a result, communication can be performed stably over almost the entire communication area A.

  In the MIMO wireless system 10, as shown in FIG. 1B, the radio wave from the leaky coaxial cable 13 arrives at a position far from the normal antenna 14 and the communication speed is maintained, and the normal antenna 14 and the leaky coaxial cable are maintained. In the intermediate region with 13, the MIMO effect works and the communication speed is maintained.

  As a result, although the upper limit of the communication speed is somewhat lower than that of the conventional MIMO wireless system, a substantially uniform communication speed can be realized over the entire communication area A.

  Next, a second embodiment will be described.

  As shown in FIG. 2A, in the MIMO radio system 20 according to the second embodiment, two or more of the plurality of antennas 12 are configured by the leaky coaxial cable 13 and each of the leaky coaxial cables 13 is It is characterized by being arranged so as to surround the normal antenna 14 with different diameters.

  In the present embodiment, four antennas 12 are connected to the radio device main body 11, two of which are configured by leaky coaxial cables 13a and 13b, and the other two are ordinary antennas (for example, the radio device main body 11). The dipole antenna element 14 installed directly on the

  Among these, two normal antennas 14 are arranged in the center of the communication area A to be constructed together with the radio device body 11, and one leaky coaxial cable 13a is arranged along the outer peripheral edge of the communication area A to be constructed. Further, the other leaky coaxial cable 13b is arranged between the radio device main body 11 (two normal antennas 14) and one leaky coaxial cable 13a.

  In the MIMO wireless system 20, as shown in FIG. 2B, at a position far from the normal antenna 14, radio waves from the leaky coaxial cable 13a reach and the communication speed is maintained.

  Further, in the intermediate region between the normal antenna 14 and the leaky coaxial cable 13a, the MIMO effect between the normal antenna 14 and the leaky coaxial cable 13b or the MIMO effect between the leaky coaxial cable 13a and the leaky coaxial cable 13b works to increase the communication speed. Kept.

  As a result, although the upper limit of the communication speed is somewhat lower than that of the conventional MIMO wireless system, a substantially uniform communication speed can be realized over the entire communication area A. In addition, the communication area A can be constructed in a wider range than the MIMO radio system 10 according to the first embodiment.

  Next, a third embodiment will be described.

  As shown in FIG. 3A, in the MIMO radio system 30 according to the third embodiment, the radio device main body 11 and a plurality of antennas 12 are connected using a coaxial cable 17, and the radio device main body 11 The arrangement and the arrangement of the plurality of antennas 12 are determined independently.

  In the present embodiment, two antennas 12 are connected to the radio device main body 11 using a coaxial cable 17, one of which is configured by a leaky coaxial cable 13, and the other is a normal antenna (for example, the radio device main body 11). And an omnidirectional antenna 14 installed via a coaxial cable 17.

  In this MIMO wireless system 30, as shown in FIG. 3B, the radio wave from the leaky coaxial cable 13 is transmitted at a position far from the normal antenna 14 as in the MIMO wireless system 10 according to the first embodiment. The transmission speed is maintained and the communication speed is maintained by the MIMO effect in the intermediate region between the normal antenna 14 and the leaky coaxial cable 13.

  As a result, although the upper limit of the communication speed is somewhat lower than that of the conventional MIMO wireless system, a substantially uniform communication speed can be realized over the entire communication area A.

  Further, since the two antennas 12 are connected to the radio device main body 11 using the coaxial cable 17 respectively, the arrangement thereof is independent of the arrangement of the radio device main body 11, and the leaky coaxial cable 13 and the normal antenna The arrangement of 14 does not depend on the arrangement of the radio main body 11.

  Therefore, the wireless device main body 11 can be arranged in a separate room or the like, and the degree of design freedom is improved when the system is constructed.

  In the above-described embodiment, an example in which the rectangular communication area A is formed is shown, but the shape of the communication area A is not particularly limited. Similarly in this case, the leaky coaxial cable 13 may be arranged along the outer peripheral edge of the communication area A.

  In the above-described third embodiment, the coaxial cable 17 is used as a cable for connecting the radio device body 11 and the plurality of antennas 12, but an optical fiber can be used. For example, when the cable length is long or the number of branches is large (when the antenna 12 is installed from one radio device body 11 to many rooms), the optical fiber is replaced with an optical fiber via a photoelectric conversion device. Even if an “optical RF” system capable of transmitting a high-frequency signal is used, the effect of the present invention remains unchanged. At this time, the optical fibers can be integrated into one by using the wavelength multiplexing technique.

  In addition, when the length of the leaky coaxial cable becomes long and a predetermined radio wave intensity cannot be obtained, even if a plurality of leaky coaxial cables are connected and used via a booster, the effect of the present invention is not changed. In this case, the booster has two systems of “up and down” at one place, and frequency is divided by a duplexer to separately amplify the upstream and downstream signals.

DESCRIPTION OF SYMBOLS 10 MIMO radio | wireless system 11 Radio | wireless machine main body 12 Multiple antennas 13 Leaky coaxial cable 14 Normal antenna 15 Building 16 Ceiling back 17 Coaxial cable A Communication area

Claims (4)

In a MIMO radio system that transmits and receives data using a plurality of antennas connected to the radio body,
The plurality of antennas includes one or more leaky coaxial cables and a normal antenna that is an antenna other than the leaky coaxial cables,
The MIMO wireless system, wherein the leaky coaxial cable is arranged so as to surround the normal antenna.   The MIMO radio system according to claim 1, wherein the normal antenna is disposed at a center portion of a communication area, and the leaky coaxial cable is disposed along an outer peripheral edge portion of the communication area.   3. The MIMO radio system according to claim 1, wherein two or more of the plurality of antennas are configured by leaky coaxial cables, and each of the leaky coaxial cables is disposed so as to surround the normal antenna with a different diameter. .   The wireless device main body and the plurality of antennas are connected using a cable, and the arrangement of the wireless device main body and the arrangement of the plurality of antennas are independently determined. The described MIMO radio system.