JPH1141655A - Interference system control system for cellular mobile communication - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid deterioration of connection quality and communication quality by an influence of an interference from other communication system by performing a communication by using the communication channel of frequency band where the central part of a radio zone is more influenced by an interference from other communication system and performing the communication by using the communication channel of the frequency band in which a peripheral part has in particular a little or no influence of interference. SOLUTION: A frequency band is set so that an order becomes B1 band, B2 band... Bn band in order of degree of influence of interference from other communication system, a band A is set in a frequency band not influence at all by other communication system and the communication channels are used depending upon circumstances. That is, when a reception level L of a mobile station is higher than LB1, the B1 band is used and, when the reception level L is between LB1 and LB2, the B2 band is used, and when the reception level L is smaller than Lbn and so on, the A-band is used similarly. Thus, influences of interference given to the quality of connection and communication can be avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-interference system control method in cellular mobile communication, which can avoid the influence of interference from other communication systems in a cellular mobile communication system such as a mobile phone, a car phone and a simplified mobile phone. More specifically, in a cellular mobile communication system in which a radio zone is formed using a plurality of different frequency bands, interference in cellular mobile communication in which a radio link is connected while avoiding the influence of connection quality and interference on communication quality It relates to a system control method.

[0002]

2. Description of the Related Art In a cellular mobile communication system in which a radio zone is formed by using a plurality of different frequency bands, interference from another communication system is simultaneously caused by a base station or a mobile station receiving side over a wide range of channels within the used band. In the case where one or a plurality of frequency bands exist, as shown in FIG. 8, the distribution example of the used frequency band in which the mobile station receiving side receives interference from the mobile station transmitting side of another system as shown in FIG. The reception bands of the stations are referred to as A1 to An band (hereinafter, referred to as A band) and B1 to Bn bands (hereinafter, referred to as B band), and the transmission band of the mobile station of another communication system whose use band exists in the vicinity is shown. Assuming the C band, the spectrum of the mobile station transmission signal in the C band is B as shown in FIG.
When the band leaks into the mobile station reception, the signal-to-noise ratio deteriorates in the B-band mobile station reception channel.

In such a situation, the signal-to-noise ratio is deteriorated regardless of which communication channel in the B band is used.
Connection quality and communication quality will be reduced. However,
Even in a situation where the entire B-band is subject to interference, since the mobile station reception level is high in the center of the wireless zone or the like, the influence of the deterioration of the signal-to-noise ratio on the connection quality and communication quality can be reduced. However, since the reception level of the mobile station is low in the vicinity of the radio zone, the influence of the deterioration of the signal-to-noise ratio on the connection quality and the communication quality becomes large. Inside, the deterioration of the communication quality appears remarkably.

The same applies to the frequency band distribution examples shown in FIGS. 9 to 11. FIG. 9 is a distribution example of a used frequency band in which interference from the mobile station transmitting side of another system is received by the base station receiving side of the own system, and transmission of the mobile station of the other system is performed from the mobile station of the own system to the base station. This is the case where interference occurs in the uplink. FIG. 10 is an example of a distribution of frequency bands in use in which interference from a base station transmitting side of another system is received by a base station receiving side of the own system. This is the case where the signal interferes with the uplink to the network. Further, FIG. 11 is an example of a distribution of the used frequency band in which the interference from the base station transmitting side of the other system is received by the mobile station receiving side of the own system, and the transmission of the base station of the other system is performed from the base station of the own system to the mobile station. This is the case where it interferes with the down link to.

In the conventional system control system, the A band and the B band can be used regardless of the degree of the influence of the interference. ) Or the communication channel used is not properly used.

[0006]

In the conventional system control system, one or a plurality of frequency bands in which interference from another communication system is simultaneously received by a base station or a mobile station on a wide range of channels within a used band. Band exists,
In a situation where interference is received in the entire frequency band, when the frequency band is used as a communication channel and when the frequency band is used, the communication quality is deteriorated due to the influence of the interference. . In particular, since the degree of deterioration of the signal-to-noise ratio is greater at the periphery of the wireless zone than at the center of the wireless zone, the connection quality and communication quality are significantly reduced.

[0007] The present invention has been made in view of the above,
The purpose is to provide a cellular mobile communication system in which one or more frequency bands exist in which a base station or a mobile station receiving side simultaneously receives interference from another communication system over a wide range of channels within the used band. Another object of the present invention is to provide an anti-interference system control method in cellular mobile communication that avoids the influence on connection quality and communication quality.

[0008]

In order to achieve the above object, according to the present invention, in a cellular mobile communication forming a radio zone using a plurality of different frequency bands, interference from another communication system is provided. If there is one or more frequency bands in which the base station or mobile station receiving side simultaneously receives over a wide range of channels within the used band, the center of the wireless zone is more affected by the influence of interference from other communication systems. Communication is performed using a communication channel of a large frequency band, and using a communication channel of a frequency band that is less affected by interference from other communication systems or a frequency band that is completely free of interference, the closer to the periphery of the wireless zone. The point is to perform communication.

According to the first aspect of the present invention, communication is performed using a communication channel in a frequency band that is more affected by interference from another communication system toward the center of the wireless zone, and the periphery of the wireless zone is controlled. The part performs communication using a communication channel in a frequency band with little influence of interference from another communication system or a frequency band without any influence of interference.

The present invention described in claim 2 is the same as the claim 1.
In the described invention, a frequency band in which interference from the other communication system is simultaneously received by a base station or a mobile station on a wide range of channels within a used band is divided into a plurality of communication channel groups, The gist is that a communication channel that is more affected by interference from a wireless zone is used in the center of the wireless zone.

According to the second aspect of the present invention, a frequency band that is subject to interference from another communication system is divided into a plurality of communication channel groups, and a communication channel that is more affected by interference from another communication system has a greater influence. Used in the center of the wireless zone.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing an example of the degree of influence of interference from another communication system in the example of frequency band distribution shown in FIG. As shown in FIG.
The influence of the interference decreases in the order of two bands,..., Bn band (a frequency band in which interference from another communication system is simultaneously received on a wide range of channels in the use band on the receiving side of the mobile station). I have.

FIG. 2 shows conditions for selectively using communication channels of band A (frequency band not affected by interference from other communication systems) and the above-described band B1, band B2,... Bn. is there. That is, the system control is performed so that the communication channel is properly used depending on the reception level of the mobile station. In FIG. 2, when the reception level L at the mobile station is high, that is, when the reception level L is higher than LB1, the communication channel B1
When the reception level L is lower than LBn, control is performed so that the A band is used when the reception level L is smaller than LBn. is there.

By controlling the communication channels so as to be selectively used in accordance with the reception level, a communication channel having a greater influence of interference is used in the center of the wireless zone, and the influence of the interference is increased in a peripheral portion of the wireless zone. Communication channel can be used.

A specific system control example will be described with reference to FIGS. FIG. 3 shows an example at the time of outgoing connection, in which a network (NW) is transmitted by an outgoing request signal from a mobile station.
Which frequency band is assigned in the wireless zone by the own zone level L reported to
It is determined which one of the 1 band, B2 band,... Bn band is used. When L ≧ LB1, a communication channel within the B1 band is allocated, and when LB1> L ≧ LB2,
Allocate a communication channel in the B2 band, LB (n-1)
If> L ≧ LBn, a communication channel in the Bn band is allocated, and if L <LBn, a communication channel in the A band is allocated.

FIG. 4 shows an example of an incoming call connection, in which a mobile station receives a call with a call signal from the network (NW), and the mobile station responds to the network (NW) with a call response signal. It determines which frequency band allocated in the wireless zone to use based on the own zone level L. L ≧ LB1
, A communication channel within the B1 band is allocated, and L
When B1> L ≧ LB2, a communication channel in the B2 band is allocated, and when LB (n−1)> L ≧ LBn, a communication channel in the Bn band is allocated, and L <LBn
In the case of (1), a communication channel within the band A is allocated.

FIG. 5 shows an example of channel switching within one radio zone during communication between the mobile station and the network (NW). The mobile station reports to the network (NW) at regular time intervals. Constantly monitor the periodic radio status report signal
If L ≧ LB1 is detected during communication as the level L of the signal, the channel is switched to a communication channel within the B1 band, and if LB1> L ≧ LB2 is detected, B
Switching the channel to a communication channel within two bands, LB
If (n-1)> L ≧ LBn is detected, the channel is switched to a communication channel in the Bn band, and L <LBn
Is detected, the channel is switched to a communication channel in the A band.

Also, in each of the B1, B2,..., Bn bands, the influence of the interference by the C band (the transmission band of the mobile station or the base station of another communication channel whose usage band is in the vicinity) exists. Different degrees. FIG. 6 shows an example of channel group division in the B1 band. Even in the B1 band, the B11 channel group close to the C band is greatly affected by the interference of the C band, and the B12 channel group is affected by the interference of the C band. , But to a lesser extent than the B11 channel group. Therefore, the frequency in the B1 band can be used effectively by further dividing the communication channels in the B1 band into channel groups.

FIG. 7 shows the use conditions of each channel group when the B1 band is divided into channel groups. When the mobile station reception level L is L ≧ LB11, the B11 channel group is used and L
When B11> L ≧ LB12, the B12 channel group is used. When LB1 (n−1)> L ≧ LB1n, the B1n channel group is used. When L <LB1n, the A band channel is used. The same applies to the B2, B3,..., Bn bands. FIGS. 3 to 5 show specific examples of system control.
Is the same as

[0021]

As described above, according to the present invention,
If there is one or more frequency bands in which a base station or a mobile station receiving side simultaneously receives interference from another communication system over a wide range of channels within the band used, the center of the wireless zone becomes closer to other communication systems. Communicate using a communication channel in a frequency band that is highly affected by interference from the system,
The closer to the periphery of the wireless zone, the communication is performed using a communication channel in a frequency band that is less affected by interference from other communication systems or a frequency band that is completely free of interference, so the influence of interference on connection quality and communication quality. Can be avoided.

Further, according to the present invention, a frequency band that is subject to interference from another communication system is divided into a plurality of communication channel groups, and a communication channel that is more affected by interference from another communication system has a larger radio zone. Since it is used at the center, the influence of interference can be avoided.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of the degree of influence of interference from another communication system in an example of frequency band distribution.

FIG. 2 shows conditions for selectively using communication channels.

FIG. 3 is an explanatory diagram showing an example of system control at the time of outgoing connection.

FIG. 4 is an explanatory diagram showing an example of system control at the time of incoming connection.

FIG. 5 is an explanatory diagram showing an example of system control for channel switching within a wireless zone.

FIG. 6 is a diagram illustrating an example of the degree of influence of channel group division and interference within the same band.

FIG. 7 is a diagram illustrating use conditions of each channel group when dividing a channel group in the B1 band.

FIG. 8 is a diagram illustrating a distribution example of a used frequency band in which interference from a mobile station transmitting side of another system is received by a mobile station receiving side of the own system.

FIG. 9 is a diagram showing an example of a distribution of used frequency bands in which interference from a mobile station transmitting side of another system is received by a base station receiving side of the own system.

FIG. 10 is a diagram showing an example of a distribution of used frequency bands in which interference from a base station transmitting side of another system is received by a base station receiving side of the own system.

FIG. 11 is a diagram illustrating an example of a distribution of used frequency bands in which interference from a base station transmitting side of another system is received by a mobile station receiving side of the own system.

Claims (2)

[Claims] In a cellular mobile communication forming a wireless zone using a plurality of different frequency bands, interference from another communication system is received simultaneously by a base station or a mobile station receiving side over a wide range of channels within the used band. When one or a plurality of frequency bands are present, communication is performed using a communication channel of a frequency band in which the influence of interference from another communication system is greater at the center of the wireless zone, and at the periphery of the wireless zone. And a communication system using a communication channel in a frequency band having little influence of interference from another communication system or a frequency band having no influence of interference. 2. A frequency band in which a base station or a mobile station receiving side simultaneously receives interference from the other communication system over a wide range of channels within a used band, and divides the frequency band into a plurality of communication channel groups. 2. The system according to claim 1, wherein a communication channel having a greater influence of interference from the mobile station is used in a central portion of the wireless zone.