JP3404011B2 - Mobile communication system - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention uses a narrow beam to
In a mobile radio communication system in which a base station and a mobile station subordinate to this base station have tracking channels for tracking each other, the mobile station and the base station (Referred to as a base station) and a method for searching for an adjacent base station during communication between a mobile station and a base station in the area.

[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 Laid-Open No. 8-8814, and in the drawing, 1101 (1101a, 1101).
b, 1101c) is a mobile station, 1102 is a base station, and 110
Reference numeral 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,
Information channels f1, f2, and 1101c, 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. From the base station 1102, as shown in FIG.
Is controlled in all azimuth directions while shifting as shown by θ1, θ2, θ3, θ4, and at the same time, the azimuth angle φ in the dip direction is also shifted to φ1, φ2, φ3, and φ4 as shown in FIG. While controlling the transmission direction.

The mobile station 1101 constantly measures the reception level together with the above azimuth and deflection information, identifies the direction with the maximum reception level as the base station direction, and determines the optimum azimuth and optimal deflection and The optimum azimuth angle reception level and the optimum azimuth angle reception level are retransmitted to the base station 1102.

The base station 1102 is the mobile station 1101 described above.
The transmission level is determined on the basis of 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 becomes difficult to select a transmission radio wave due to interference waves coming from a plurality of base stations.

[0007] Further, in the "radio communication system" disclosed in Japanese Patent Laid-Open No. 5-276084, a mobile radio communication system using a directional antenna and a phased array in a mobile station and a base station is shown. As a method of irradiating an omnidirectional pattern to start the above, two methods of preparing a phased array antenna dedicated to connection and appropriately adjusting a phase shifter of the array itself are described.

According to the above-mentioned method, one emits omnidirectional radiation, and the other emits directional radiation in the detected direction, and then 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 amplitude value information, and channel switching can be performed by the above method even when crossing the area of another base station. There is.

However, in the method as described above, it is necessary to perform omnidirectional radiation without fail, and it is necessary to provide both omnidirectional and narrow beam radiation systems.

[0010]

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

In addition, another conventional method has a problem that both the omnidirectional channel and the narrow beam channel must be provided in order to start a call.

Further, in the overlap area in which the mobile station and the plurality of base stations can communicate with each other, while the base station in the serving area and the mobile station are communicating, the above-mentioned channel is provided between both the adjacent base station to be handed over and the mobile station. Requires different tracking channels, and in the above-mentioned overlap area area, tracking channels are set for different frequencies / transmitted radio waves to avoid interference between adjacent base stations and mobile stations There is a problem that time increases.

The present invention has been made in order to solve such a problem, in which both a base station and a mobile station do not need an omnidirectional channel as a channel for tracking each other and only a narrow beam channel is used. In addition, in the overlap area, while the base station in the serving area and the mobile station are communicating, it is an object of the present invention to provide a system capable of shortening the tracking time for the adjacent base station and the mobile station to search each other for the other party. 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 by using a narrow beam and a communication channel for communicating with each other. In the mobile communication system, the mobile station and the base station, in order to track the positions of each other, the transmission side of the base station comprises a transmission radio wave direction control means for controlling the direction of the transmission radio wave related to the tracking channel, The receiving side of the mobile station comprises a receiving direction control means for changing the receiving direction when receiving the transmission radio wave related to the tracking channel, and the base station changes the transmitting direction of the tracking channel in the down direction and forms a narrow beam. Swinging in all directions, the mobile station changes the receiving direction of the narrow beam, and sets the receiving direction of the downlink tracking channel as the transmitting direction and And transmits an uplink tracking channel direction,
The base station stops the swing operation of the narrow beam by receiving the uplink tracking channel and irradiates the narrow beam in the received direction, thereby changing the transmission / reception direction of the communication channel of the base station and the mobile station. These are the transmission and reception directions.

In the mobile communication system according to the present invention, after the mutual tracking between the mobile station and the in-area base station is completed, the mobile station and the in-area base station are the same as those used in the tracking channel. It is provided with a switching means for switching to the information channel by using the frequency and the transmission radio wave.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. FIG. 1 is a block diagram of a mobile communication system according to the present invention. In FIG.
01 (101a to 101g) is a mobile station, and 102 (102
a-102e) accommodates the mobile station 101,
01 is a base station wirelessly connected, 103 is a base station controller that manages the base station 102, and 104 is the base station controller 10.
It is an exchange station that is connected to 3 by wire.

Next, the operation will be described. FIG. 2 is a conceptual diagram showing a control example of the reception angle direction of the mobile station. In the figure, the same symbols as in FIG. 1 indicate the same or corresponding parts. Further, FIG. 3 is a flow chart showing a flow up to the tracking process in the base station and the start of communication, and FIG. 4 is a flow chart showing a flow up to the tracking process and transmission in the mobile station.
Further, FIG. 5 is a sequence diagram showing a sequence from the tracking process between 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 the mobile radio communication system having the search channel for controlling the irradiation direction of the narrow beam, all the base stations 102 use the tracking channel in the down direction as shown in the conventional example, and the corner angle φ. And azimuth θ are shown in Fig. 5
While changing the narrow beam to be transmitted while changing it as in (2) (step S0001), a base station identifier for identifying the base station 102 as shown in FIG. Send ID (step S0)
002).

Further, the mobile station 101 changes the receiving direction of the transmitted radio wave as shown in FIG. 2 so that the tracking channel including the base station ID is transmitted from the in-area base station 102 as shown in FIG. 5 (1). Wait (steps S0101, S01
02). The receiver (not shown) of the mobile station 101 may be able to receive conventional omnidirectional directions depending on parameters.

The mobile station 101 receives the downlink tracking channel from the existing area base station 102 to acquire the existing area base station ID (step S0103), and as shown in FIG. The transmission direction is determined by the method (step S0104), and the mobile station identifier (hereinafter, mobile station ID) for identifying the mobile station 101 in that direction and the in-area area base station ID are used in the uplink tracking channel as shown in FIG. 5 (5). It is transmitted (step S0105).

Further, as shown in FIG. 5 (11), an uplink tracking channel end signal is transmitted (step S0106), and thereafter, as shown in FIG. 5 (12), the frequency of the uplink tracking channel and Figure 5 using transmitted radio waves
As in (13), the tracking channel is switched to the information channel and transmitted (step S0107).

As described above, according to this embodiment, after the mutual tracking between the mobile station 101 and the in-area base station 102 is completed, the same frequency and transmission radio wave used in the tracking channel are transmitted. Since it is used to switch to the information channel, unlike the conventional system, it is not necessary to switch the tracking channel and the information channel with different frequencies and transmission radio waves, and the device configuration is simplified.

Further, according to this embodiment, not only is the area-in-area base station 102 changing the transmission direction of the transmitted radio wave, but the mobile station 101 is also changing the reception direction, so that the receiving side is in the in-area area. It becomes possible to more accurately receive the transmission radio wave emitted by the base station 102, the reception level of the narrow beam at the mobile station 101 becomes stronger, and in the area where the plurality of base stations 102 overlap by that amount, another adjacent base station 102 can be received. Interference from can be reduced.

Embodiment 2. On the other hand, in-area base station 1
02 receives the mobile station ID when it receives the uplink tracking channel from the mobile station 101 (step S0
004), the transmission direction of the beam is determined by the same method as the conventional example as shown in FIG. 5 (6), and the swinging operation of the narrow beam that was being swung for exploration is stopped (step S0005).
As shown in (7), a narrow beam indicating a downlink tracking channel end signal is emitted in the downlink tracking channel in the received direction (step S0006).

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

Further, when the mobile station 101 receives the downlink tracking channel end signal from the in-area base station 102, the mobile station 101 starts receiving the downlink information channel as shown in FIG.

When the in-area-area base station 102 receives the uplink tracking channel end signal from the mobile station 101,
3) The uplink information channel is transmitted. This enables bidirectional communication between the in-area base station 102 and the mobile station 101.

During communication, the azimuth angle and reception level information is measured at any time, and the azimuth angle and reception level information is always sent from the mobile station 101 using the control slot for transmitting and receiving the control signals shown in FIG. Area base station 102
Based on this information, the in-area base station 102 determines the irradiation direction of the narrow beam and adjusts the control.

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 same frequency and beam used for the tracking channel are used to switch to the information channel. The operation of switching the channel and the information channel to another frequency and beam is not necessary, and the device configuration is simplified.

[0030]

According to the present invention, not only is the in-area base station changing the transmission direction of the transmission radio wave relating to the tracking channel, but the mobile station also changes the reception direction when receiving the transmission radio wave relating to the tracking channel. By changing it, it becomes possible for the receiving side to more accurately receive the transmission radio waves emitted by the base station in the area, and the reception level of the narrow beam at the mobile station becomes stronger, and multiple base stations overlap by that amount. It is possible to reduce the interference from other adjacent base stations in the area.

According to the present invention, after the mutual tracking between the mobile station and the existing area base station is completed, the same frequency and the transmission radio wave used for the tracking channel are used to switch to the information channel. Therefore, unlike the conventional system, there is no need to switch the tracking channel and the information channel by using different frequencies and transmission radio waves, and the device configuration can be simplified.

[Brief description of drawings]

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

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

FIG. 3 is a flowchart showing a flow until a tracking process and communication start in a base station.

FIG. 4 is a flowchart showing a flow up to tracking processing and transmission in the mobile station.

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

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

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

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

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

[Explanation of symbols]

101 mobile station, 102 base station, 103 base station control device, 104 exchange station.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-7-87011 (JP, A) JP-A-6-69847 (JP, A) JP-A-9-238105 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) H04B ^7/ 24-7/26 102 H04Q ^7/ 00-7/38

Claims (2)

(57) [Claims] 1. A mobile station, a base station such as an in-area base station or at least one adjacent base station that manages an area in which the mobile station is located, and a base station control device that manages the base station. In a mobile communication system in which both the mobile station and the base station have a communication channel for communicating with each other and a tracking channel for tracking each other using a narrow beam, the mobile station and the base station are both In order to track the position of each other, the transmission side of the base station is equipped with a transmission radio wave direction control means for controlling the direction of the transmission radio wave related to the tracking channel, and the reception side of the mobile station is transmitted radio wave related to the tracking channel. The base station is provided with a reception direction control means for changing the reception direction when receiving a signal, and the base station changes the transmission direction of the tracking channel in the downlink direction and sways a narrow beam in all directions. , The mobile station changes the reception direction of the narrow beam, sets the reception direction of the downlink tracking channel as the transmission direction, and transmits the uplink tracking channel in that direction, and the base station receives the uplink tracking channel. By stopping the swinging operation of the narrow beam by irradiating the narrow beam in the received direction by doing so, the transmission and reception directions of the communication channel of the base station and the mobile station are these transmission and reception directions. Mobile communication system. 2. After mutual tracking between the mobile station and the existing area base station is completed, the mobile station and the existing area base station use the same frequency and transmission radio wave as those used in the tracking channel. The mobile communication system according to claim 1, further comprising switching means for switching to an information channel.