JP2001077750A - Mobile communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To unnecessitate an omniazimuth channel by not only allowing an in-circle area base station to vary the transmitting direction of radio signals concerning a tracking channel but also allowing a mobile station to vary a receiving direction at the time of receiving the transmission radio signals, so as to implement a channel where both of the base station and the mobile station track each other. SOLUTION: All the base stations 102a to 102e transmit base station IDs for identifying the base stations 102a to 102e while scanning a narrow beam to be transmitted omnidirectionally while varying angles of elevation and azimuth through the use of a down tracking channel. Mobile stations 101a to 101g wait for a tracking channel including the base station ID from an in-circle area base station by varying the receiving direction for radio signals transmitted from the base stations. Then, the stations 101a to 101g receive the down tracking channel from an in-circle area base station to obtain the in-circle area base station ID, decide a transmitting direction and transmit the mobile station ID for identifying the mobile station and an in-circle area base station ID in the direction through an up tracking channel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to the use of a narrow beam.
In a mobile radio communication system having a tracking channel for a base station and a mobile station under the control of the base station to track each other, the mobile station and the base station (the area in which the mobile station moves are managed so The present invention relates to a tracking method in a base station) and a method for searching for an adjacent base station during communication between a mobile station and a serving area base station.

[0002]

2. Description of the Related Art FIG. 7 is a block diagram of a conventional "mobile radio communication system" disclosed in, for example, Japanese Patent Application Laid-Open No. 8-8814.
b, 1101c) is a mobile station, 1102 is a base station, 110
3 is a base station antenna.

Next, the operation will be described. In FIG. 7, channels having different frequencies are assigned to each mobile station. For example, mobile stations 1101a, 1101b,
1101c for information channels f1, f2, respectively.
f3 is assigned. The mobile radio communication system further includes a common frequency channel f0 in the base station for transmitting the beam direction information of the antenna directivity, and the base station 1102 outputs the azimuth θ in the horizontal direction as shown in FIG.
Is controlled in all directions while shifting θ1, θ2, θ3, θ4, and at the same time, the azimuth φ in the angular direction is also shifted to φ1, φ2, φ3, φ4 in the angular direction as shown in FIG. While controlling the transmission direction.

[0004] The mobile station 1101 measures the reception level at any time together with the azimuth and angle information, identifies the direction in which the reception level is maximized from the direction of the base station, and determines the optimum azimuth and angle and angle. The optimum azimuth reception level and the optimum reception level are retransmitted to the base station 1102.

[0005] The base station 1102 is connected to the mobile station 1101 described above.
The transmission level is determined based on the reception level of the optimum azimuth angle and the reception level of the optimum angle, and the transmission level is controlled so as to prevent interference with other base stations.

However, when a mobile station approaches a boundary with an adjacent base station, there is a problem that it is difficult to select a transmission radio wave due to interference waves arriving from a plurality of base stations.

[0007] Japanese Patent Laid-Open Publication No. Hei 5-276084 discloses a "wireless communication system" which uses a directional antenna and a phased array for mobile stations and base stations. As a method of irradiating an omnidirectional pattern to start the operation, there are described a method of preparing a phased array antenna dedicated to connection and a method of appropriately adjusting a phase shifter of the array itself.

In the above-described method, one emits omnidirectional radiation and the other emits directional radiation in the detected direction when the radiation is detected, and thereafter the phase received by the phased array antenna. A method is described in which the transmission direction of the directional antenna is corrected at any time based on the value and the amplitude value information, and the channel can be switched in the above-described manner even when crossing the area of another base station. I have.

However, in the above-described method, it is necessary to perform omnidirectional radiation, and it is necessary to provide a radiation system for both omnidirectional radiation and narrow beam radiation.

[0010]

As described above, according to the conventional method, when a mobile station approaches a boundary with an adjacent base station, it becomes difficult to select a beam due to interference waves coming from a plurality of base stations. There's a problem.

Further, another conventional method has a problem that it is necessary to have both an omnidirectional channel and a narrow beam channel in order to start a call.

Further, in the overlap area where the mobile station and a plurality of base stations can communicate with each other, while the serving area base station and the mobile station are communicating with each other, the channel is established between the adjacent base station to be handed over and the mobile station. Requires a different tracking channel, and in the overlap area described above, sets a different frequency / transmitted radio wave tracking channel between the adjacent base station and the mobile station to avoid interference, and performs tracking in both areas. There is a problem that time increases.

The present invention has been made to solve such a problem, and both a base station and a mobile station do not need an omnidirectional channel as a channel for tracking each other, and use only a narrow beam channel. Further, it is an object of the present invention to provide a system capable of shortening a tracking time for an adjacent base station and the above-mentioned mobile station to search for each other in the overlapping area while the serving area base station and the mobile station are communicating with each other. And

[0014]

A mobile communication system according to the present invention has a tracking channel for both a mobile station and a base station to track each other using a narrow beam and a communication channel for communicating with each other. In a mobile communication system, the mobile station and the base station track both positions of each other, and the transmitting side of the base station includes transmission radio wave direction control means for controlling a direction of a transmission radio wave related to the tracking channel. The receiving side of the mobile station includes receiving direction control means for changing a receiving direction when receiving a transmission radio wave related to the tracking channel, and the base station changes a transmitting direction of the downstream tracking channel and reduces a narrow beam. Shaking in all directions, the mobile station changes the reception direction of the narrow beam, and sets the reception direction of the downlink tracking channel as the transmission direction, And transmits an uplink tracking channel direction,
The base station receives the uplink tracking channel, stops the narrow beam swing operation, and irradiates the narrow beam in the received direction, thereby changing the transmission / reception direction of the communication channel between the base station and the mobile station. These are the transmission and reception directions.

[0015] In the mobile communication system according to the present invention, after the mutual tracking between the mobile station and the visited area base station is completed, the mobile station and the visited area base station are in the same state as used in the tracking channel. A switching means for switching to an information channel using a frequency and a transmission radio wave is provided.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a configuration diagram of a mobile communication system according to the present invention.
01 (101a to 101g) is a mobile station, and 102 (102
a to 102e) accommodate the mobile station 101 and this mobile station 1
01, a base station that wirelessly connects to the base station 103, a base station controller 103 that manages the base station 102, 104, a base station controller 10
3 is an exchange connected by wire.

Next, the operation will be described. FIG. 2 is a conceptual diagram showing an example of the control of the mobile station in the receiving angle direction. In the figure, the same reference numerals as those in FIG. FIG. 3 is a flowchart showing a flow from the base station to tracking processing and communication start, and FIG. 4 is a flowchart showing a flow from the mobile station to tracking processing and transmission.
FIG. 5 is a sequence diagram showing a sequence from the tracking processing of the mobile station and the base station to the communication state, and the numbers shown in parentheses in the figure indicate the order.

According to the present invention, in a mobile radio communication system having a search channel for controlling the irradiation direction of a narrow beam, all base stations 102 use a tracking channel in a downward direction as shown in the conventional example, and an angle φ And the azimuth θ
As shown in FIG. 5 (3), a base station identifier for identifying the base station 102 (hereinafter referred to as “base station”) while changing the transmitting narrow beam in all directions (step S0001) as shown in (2). (Step S0)
002).

The mobile station 101 changes the receiving direction of the transmission radio wave as shown in FIG. 2 so that the tracking channel including the base station ID is transmitted from the serving area base station 102 as shown in FIG. Wait (steps S0101, S01)
02). In the receiver (not shown) of the mobile station 101, conventional omnidirectional reception may be possible depending on parameters.

The mobile station 101 obtains the serving area base station ID by receiving the downlink tracking channel from the serving area base station 102 (step S0103), and as shown in FIG. The transmission direction is determined by the method (step S0104), and as shown in FIG. 5 (5), the mobile station identifier (hereinafter, mobile station ID) for identifying the mobile station 101 and the serving area base station ID are determined by the uplink tracking channel. It transmits (step S0105).

Further, an uplink tracking channel end signal is transmitted as shown in FIG. 5 (11) (step S0106), and thereafter, as shown in FIG. Fig. 5
The tracking channel is switched to the information channel as in (13) and transmitted (step S0107).

As described above, according to this embodiment, after the mutual tracking between mobile station 101 and serving area base station 102 is completed, the same frequency and transmission radio wave as used in the tracking channel are used. Therefore, unlike the conventional system, there is no need to switch between the tracking channel and the information channel using different frequencies and transmission radio waves, thereby simplifying the configuration of the apparatus.

According to the present embodiment, not only is the serving area base station 102 changing the transmission direction of the transmission radio wave, but also the mobile station 101 changes the receiving direction. It becomes possible to receive the transmission radio wave emitted from the base station 102 more accurately, the reception level of the narrow beam in the mobile station 101 becomes stronger, and the adjacent base station 102 in the area where the plurality of base stations 102 overlap is correspondingly increased. Can be reduced.

Embodiment 2 FIG. On the other hand, the serving area base station 1
In step 02, when an uplink tracking channel is received from the mobile station 101, the mobile station ID is acquired (step S0).
004), the beam transmission direction is determined by the same method as in the conventional example as shown in FIG. 5 (6), and the narrow beam swing operation that has been swung for the search is stopped (step S0005).
As shown in (7), a narrow beam indicating a downstream tracking channel end signal is emitted on the downstream tracking channel in the received direction (step S0006).

Further, the serving area base station 102 is shown in FIG.
As in (8), the information channel is transmitted using the frequency and the beam of the tracking channel as they are (step S0007), and the mobile station 101 waits for the arrival of the uplink tracking channel end signal.

When receiving the downlink tracking channel end signal from the serving area base station 102, the mobile station 101 starts receiving the downlink information channel as shown in FIG.

When the serving area base station 102 receives the uplink tracking channel end signal from the mobile station 101, the base station 102 in FIG.
The transmission of the uplink information channel of 3) is performed. As a result, bidirectional communication between the serving area base station 102 and the mobile station 101 becomes possible.

During the communication, the information of the azimuth and the reception level is measured at any time, and the information of the azimuth and the reception level is always present from the mobile station 101 using the control slot for transmitting and receiving the control signal shown in FIG. Service area base station 102
The base station 102 determines the irradiation direction of the narrow beam and adjusts the control based on this information.

As described above, according to this embodiment,
After the mutual tracking between the mobile station 101 and the parked area base station 102 is completed, the mobile station 101 switches to the information channel by using the same frequency and beam used in the tracking channel, so that tracking is performed as in the conventional system. The operation of switching the channel and the information channel to different frequencies and beams becomes unnecessary, and the device configuration is simplified.

[0030]

According to the present invention, not only is the serving area base station changing the transmission direction of the transmission radio wave relating to the tracking channel, but also the mobile station changes the reception direction when receiving the transmission radio wave relating to the tracking channel. By changing, the receiving side can receive the transmission radio wave emitted by the serving area base station more accurately, the receiving level of the narrow beam in the mobile station becomes stronger, and the base stations overlap accordingly. This has the effect of reducing interference from other adjacent base stations in the area.

According to the present invention, after the mutual tracking between the mobile station and the serving area base station is completed, the mobile station and the serving area base station are switched to the information channel by using the same frequency and transmission radio wave used in the tracking channel. This eliminates the need for an operation of switching the tracking channel and the information channel between different frequencies and transmission radio waves as in the conventional system, and has the effect of simplifying the device configuration.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a mobile communication system according to the present invention.

FIG. 2 is a conceptual diagram illustrating a control example of a mobile station in a reception angle direction.

FIG. 3 is a flowchart showing a flow up to tracking processing and communication start in a base station.

FIG. 4 is a flowchart showing a flow from tracking processing to transmission in a mobile station.

FIG. 5 is a sequence diagram showing a sequence from tracking processing between a mobile station and a base station to a communication state.

FIG. 6 is a configuration diagram showing a configuration of a tracking slot and a control slot on an information channel.

FIG. 7 is a configuration diagram showing a configuration example of a conventional control system using a narrow beam.

FIG. 8 is a diagram illustrating an example of transmission control of a narrow beam in an azimuth direction in a conventional base station.

FIG. 9 is a diagram illustrating an example of control in the angular direction of a narrow beam in a conventional base station.

[Explanation of symbols]

101 mobile station, 102 base station, 103 base station controller, 104 switching center.

Claims (2)

[Claims] A mobile station, a base station such as a serving area base station or at least one adjacent base station that controls an area where the mobile station is located, and a base station control device that manages the base station. A mobile communication system having a communication channel for communicating with each other and a tracking channel for both of the mobile station and the base station to track each other using a narrow beam, wherein the mobile station and the base station are both In order to track the positions of the base stations with each other, the transmitting side of the base station includes transmission radio wave direction control means for controlling the direction of the transmitting radio waves related to the tracking channel, and the receiving side of the mobile station uses the transmitting radio waves related to the tracking channel. Receiving direction control means for changing the receiving direction when receiving the signal, and the base station changes the transmitting direction of the downstream tracking channel and swings the narrow beam in all directions. The mobile station changes the receiving direction of the narrow beam, sets the receiving direction of the downlink tracking channel as a transmitting direction, and transmits an uplink tracking channel in that direction, and the base station receives the uplink tracking channel. By stopping the swinging operation of the narrow beam and irradiating the narrow beam in the received direction, the transmitting and receiving directions of the communication channel of the base station and the mobile station are set to these transmitting and receiving directions. Mobile communication system. 2. After the mutual tracking between the mobile station and the serving area base station is completed, the mobile station and the serving area base station use the same frequency and transmission radio wave as used in the tracking channel. The mobile communication system according to claim 1, further comprising a switching unit for switching to an information channel.