JPS5851634A - Mobile communication system - Google Patents

Abstract

PURPOSE:To improve the efficiency of use of frequencies, through the coincidence of both radio zones, by controlling a transmission output of itself so that the output is made coincident with a transmission output of a portable telephone set, in receiving coexisting information of a car telephone set from a radio base station of a district. CONSTITUTION:When coexisting information transmitted from radio base station with a control signal is received via an antenna A1, a transmission/reception branching filter H1, and a reception section R, a control section CPU applies the control signal to a power amplifying section AMP of a car mounting adaptor AD to decrease the amplification factor so that an output level of a car telephone set is coincident with that of a portable telephone set, the control signal is applied to the reception section R and the reception sensitivity can be made coincident with that of the portable telephone set. Thus, disadvantages that the car telephone set should always change over channels even in a district without coexistence as conventional systems can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides that when a car phone and a mobile phone coexist,
The present invention relates to a mobile communication system that can obtain high frequency utilization efficiency.

In recent years, subscribers who have had many opportunities to travel widely,
There is a demand for a mobile phone service that allows users to receive mobile phone services using a portable telephone. Currently, the car phone system is used to provide telephone services to a large number of mobile subscribers, but mobile phones must be designed to be smaller than car phones. Due to constraints on power supply capacity, heat radiation, etc., the radio wave propagation distance is shorter than that of a car phone, and the antenna gain is low because it is worn on the human body when carried.

In this way, when a car phone and a mobile phone with different radio wave propagation distances, antenna gains, etc. are co-located, a method of configuring all wireless zones according to the output level of the mobile phone (V, H, M * e Da＊ald '?'A#
Ce1la11ar Cmneapt” B, S, T,
J, Val, 5B, Na, 1.197? ) has been proposed, but this method configures the wireless zone according to the output level of the mobile phone, regardless of whether or not a car phone and a mobile phone coexist.
Car telephones, which move at high speed, have the disadvantage that they must be constantly connected to channels even in areas where they do not coexist with mobile phones.

Another method is to place multiple receivers within the wireless zone of a car phone, taking into account the radio wave propagation distance of the mobile phone, and use these receivers to receive radio waves from the mobile phone and send them to the wireless base station. However, in this system, the repetition distance of mobile phones (distance between areas where the same frequency can be used) is equal to the repetition distance of the car phone system, so it is often used as a car phone. The drawback is that it is difficult to obtain a sufficient frequency utilization rate to allow mobile phones, which are expected to have many subscribers, to coexist with car phones.

The present invention has been made to improve the above-mentioned drawbacks, and its purpose is to make it possible to obtain sufficient frequency utilization efficiency when a car phone and a mobile phone coexist. Examples will be described in detail below.

First, to briefly explain the method of the present invention, a wireless base station in an area where car phones and mobile phones coexist uses a control channel that sends position information, an incoming call signal to a mobile device, etc.
Coexistence information indicating that the car phone and mobile phone coexist is added to this information and sent out. Also, by receiving the coexistence information, the car phone reduces its output level and transmits the coexistence information. This is to match the output level of the telephone. That is, the system of the present invention reduces the output level of the car phone and makes the wireless zones of the car phone and the mobile phone coincide only in areas where car phones and mobile phones coexist. Even in areas where the two do not coexist, the drawback that the car phone has to switch channels all the time can be eliminated, and in areas where the two coexist, the wireless zone can be adjusted to match the output level of the mobile phone. Since the frequency is divided into small zones, high frequency utilization efficiency can be obtained.

FIG. 1 is a block diagram of an embodiment of the present invention, showing the configuration of a car telephone used in the system of the present invention. In the same figure, A1. A2 is the antenna, Hl
, H2 is a transmitting/receiving duplexer, the fake is a power amplifier, CON is a connector, SWl, SII'2 is a switch, R is a receiving section, S is a transmitting section, SYN is a synthesizer section, cpv is a control section, T
is a telephone, AD is a vehicle adapter, and P is a mobile unit. The mobile part P is connected to the in-vehicle adapter part AI) via the connector CON, and can be freely removed from the connector CON. It is designed to function as a telephone. Also, switch 5F1,
SF3 is turned off as shown in the figure when the portable part P is attached to the connector CON K.
It is turned on when it is removed from the device.

The above-mentioned coexistence information sent from a wireless base station (not shown) via a control channel is transmitted to the antenna A1 and the transmitting/receiving duplexer H.
1. When received via the receiving unit R, the control unit CPU applies a control signal to the power amplification unit xp of the in-vehicle adapter AD, and adjusts the amplification factor so that the output level of the car phone matches the output level of the mobile phone. At the same time, the receiving section R
A control signal is added to the signal to match the reception sensitivity of the mobile phone. In addition, if the car phone moves from an area where a car phone and a mobile phone coexist to an area where both do not coexist, and it becomes possible to receive coexistence information, the control device cpv controls the power amplifier unit AMP. and receiving section R
A control signal is applied to the signals to return their amplification factors and reception sensitivities to their normal states.

Oka: The output level of a wireless base station installed in an area where car phones and mobile phones coexist should be matched to the reception sensitivity of the mobile phone.

Also, even if the car phone moves from an area where a car phone and a mobile phone coexist to an area where they do not coexist during a call, or from an area where the two do not coexist to an area where both coexist, the channel If you add coexistence information to the information for switching and send it out, as described above,
It is possible to reduce the transmission level and reception sensitivity of car telephones only in areas where both coexist, and to make the radio zones of the two coincide.

As explained above, the present invention transmits coexistence information indicating that the car phones and mobile phones coexist using a control channel in areas where car phones and mobile phones coexist, and the car phones coexist. A control unit C that matches its transmission output with the transmission output of the mobile packing machine by receiving information.
Equipped with a control means consisting of a PU, a power amplification unit AMP, etc.
In areas where car phones and mobile phones coexist, it is possible to match the wireless zones of both, and the wireless zone can be made into smaller zones, which has the advantage of improving frequency usage efficiency. . Furthermore, since the wireless zone is divided into small zones only in areas where car phones and mobile phones coexist, car phones do not have to constantly switch channels even in areas where both do not coexist, unlike the conventional system. It also has the advantage of eliminating the disadvantages of having to do so.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention. A1. A2 is antenna H1, H2 is transmitter/receiver splitter, AMP
is the power amplifier section, CON is the connector, SWl, STl'
2 is a switch, R is a receiving section, S is a transmitting section, SYN is a synthesizer part, CPU is a control section, T is a telephone, AD is an in-vehicle adapter, and P is a portable section.

Claims (1)

[Claims] Coexistence information indicating that the car phone and the mobile phone coexist is transmitted through mobile communication using a communication channel and a control channel, and the car phone transmits the transmitted output to the mobile phone by receiving the coexistence information. A mobile communication system characterized by comprising a control means to match the transmission output of a telephone, and to match the radio zones of car phones and mobile phones in areas where both of them coexist.