JP2699684B2 - Mobile receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile receiver shared by a plurality of mobile communication systems.

[0002]

2. Description of the Related Art When a mobile terminal is powered on and is not performing operations such as outgoing calls, incoming calls, location registration, etc., the mobile terminal is in a standby state for incoming calls, and the incoming call is controlled in a control zone in which the mobile terminal is located. Select a channel and receive it. The mobile terminal control at the time of standby is described in "Automobile Telephone" (Electronic Communication Society, 1985), p.
It is described in detail on page 85.

It is conceivable that a plurality of mobile communication systems, such as a cordless telephone and a car telephone, provide services in the same place, and one mobile terminal can receive services of a plurality of systems. At this time, if a plurality of systems independently perform location registration and paging of the mobile terminal, there is a possibility that the paging is always performed from each system, so that a plurality of independent systems are required to receive the termination control channel of each system. A receiver is required. FIG.
FIG. 2 is a diagram showing such a situation, in which a base station 70 of a car telephone system and a base station 8 of a local cordless telephone system are shown.
0 independently sends a control signal to the mobile terminal 90 in the building 110.

On the other hand, a received wave in mobile communication undergoes fading, and its envelope level frequently drops to near the thermal noise level of the receiver, which hinders high-quality transmission. Diversity reception using two or more received waves is common. This diversity is described in pages 161 to 187 of "Basics of Mobile Communication" (The Institute of Electronics and Communication Engineers, 1986) supervised by Yoshihisa Okumura and Masaaki Shinshi.
It is detailed on the page. Even when performing diversity reception, for example, when performing selective combining, a plurality of independent receivers are required.

[0005]

As described above, a plurality of receivers are required both for waiting for an incoming call from a plurality of mobile communication systems and for diversity reception. Therefore, when trying to realize both at the same time, even if the number of receivers used at the same time is, for example, two, respectively, these cannot be used effectively, and the number of receivers as a whole becomes larger than two. . As described above, the conventional mobile receiver has a problem to be solved when shared by a plurality of mobile communication systems.

[0006]

SUMMARY OF THE INVENTION A mobile receiver according to the present invention comprises:
A mobile receiver shared as a receiver of a plurality of mobile communication systems, comprising: a plurality of antennas; a plurality of frequency converters for independently frequency-converting signals from the respective antennas; and the respective frequency converters A plurality of demodulators for demodulating the outputs of the demodulators, a plurality of output terminals for independently outputting the outputs of the respective demodulators, a synthesizing circuit for synthesizing the outputs of the plurality of demodulators, A plurality of switches for switching the output to the demodulator output terminal or the combining circuit; and at least two or more demodulators receiving calls from different mobile communication systems when in a standby state for incoming calls from a plurality of mobile communication systems. A different frequency is set in the frequency converter so as to receive a call signal, and a changeover switch outputs the demodulator output to each of the demodulators. The mobile terminal is connected to a receiver output terminal, and when not waiting for an incoming call from a plurality of mobile communication systems, the frequency of a signal from one of the mobile communication systems communicating with the mobile receiver is at least temporarily changed to the frequency conversion. And a control circuit that controls the changeover switch to connect the demodulator output to the synthesis circuit.

[0007]

In the mobile receiver of the present invention, when in the standby state, a plurality of receiving circuits are used to receive the incoming control channel of each system, and the outputs of the receiving circuits are output independently as they are by switching. When performing diversity reception while communicating with one system, the receiving circuit used for receiving the incoming control channel is controlled in a standby state to control the frequency conversion circuit so as to receive a signal from the communicating system, and switches are switched. The output of the receiving circuit is input to the combining circuit. In this way, the same receiving circuit can be used for standby of different systems and for diversity reception.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in detail with reference to the drawings. FIG. 1 shows an embodiment of the present invention. The signals received from the antennas 10 and 11 are
The signal is converted to a desired frequency by the demodulators 30 and 31 at 0 and 21.
Sent to Here, the frequency converter 20 includes the variable frequency oscillator 3 and the multiplier 1, and the frequency converter 2
Reference numeral 1 denotes a variable frequency oscillator 4 and a multiplier 2. The frequency converters 20 and 21 can control the frequency independently of each other by a signal from the control circuit 50. The demodulators 30 and 31 each demodulate the received signal. The switches 40 and 41 output the demodulator output according to the signal from the control circuit 50, and output the demodulator output terminals 100 and 101.
Alternatively, the input is switched to the input of the synthesis circuit 60. When the demodulator output is connected to the demodulator output terminals 100 and 101 by the switch, the demodulated signal is output as it is, and when connected to the synthesizing circuit 60, the signal synthesized by the synthesizing circuit 60 is output. Output to the output terminal 102.

A terminal 103 receives a communication state of the terminal. When the terminal is in a standby state from a plurality of mobile communication systems, the control circuit 50 sets the frequency conversion circuits 20 and 21 to the frequency of the incoming control channel through which the incoming call information of each system is transmitted, and sets the switches. By connecting the terminals 40 and 41 to the demodulator output terminals 100 and 101, respectively, a plurality of incoming signals are independently monitored. On the other hand, when the terminal is communicating with one system, the control circuit 50 sets the frequency conversion circuits 20 and 21 to the frequency of the signal from the system and sets the switches 40 and 41 to the combining circuit 60, respectively. By connecting, diversity reception is performed. By doing so, a mobile receiver that can use the same receiving circuit for standby from a plurality of mobile communication systems and for diversity reception can be realized.

It is clear that any diversity combining method may be employed during communication with one mobile communication system in the present invention, and two signals used for diversity may have the same frequency or different frequencies. And the number of base stations transmitting the signal may be one or more.

[0011]

According to the present invention, the same receiving circuit can be used for standby in different systems and for diversity reception. Therefore, a mobile receiver capable of both standby and diversity reception in a plurality of systems can be provided. It can be provided with a small number of receiving circuits.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of a mobile receiver of the present invention.

FIG. 2 is a conceptual diagram illustrating a usage mode of a mobile terminal that can be used in a plurality of mobile communication systems.

[Explanation of symbols]

 10, 11 antenna 20, 21 frequency conversion circuit 30, 31 demodulator 40, 41 switch 50 control circuit 60 synthesis circuit 100, 101 demodulator output terminal 102 synthesis circuit output terminal 103 control circuit input terminal 70 base station 80 for mobile phone system Base station of premises cordless telephone system 90 Mobile terminal 110 Building

Claims (1)

(57) [Claims] 1. A mobile receiver shared as a receiver for a plurality of mobile communication systems, comprising: a plurality of antennas; and a plurality of frequency converters for frequency-converting signals from the respective antennas independently of each other; A plurality of demodulators for demodulating the outputs of the respective frequency converters, a plurality of output terminals for independently outputting the outputs of the respective demodulators, and a combining circuit for combining the outputs of the plurality of demodulators, A plurality of switches for switching the output of each demodulator to the demodulator output terminal or the synthesizing circuit; and at least two or more different demodulators when waiting for an incoming call from a plurality of mobile communication systems. The frequency of the incoming control channel from the communication system is set in each of the frequency converters, and the changeover switch precedes the demodulator output. Connected to the demodulator output terminal, and when not in a standby state for an incoming call from a plurality of mobile communication systems, the frequency of a signal from any of the mobile communication systems in communication with the mobile receiver at least temporarily. And a control circuit for setting the frequency converter and controlling the changeover switch to connect the demodulator output to the synthesis circuit.