JPS61136325A - Moving body communication system - Google Patents

Abstract

PURPOSE:To prevent a transmitter and a receiver from being operated simultaneously, by radiating alternately an electromagnetic wave from one of radio communication equipments, between said equipments provided with a transmitter and a receiver, and setting its switching frequency to a signal frequency or above. CONSTITUTION:In case an electromagnetic wave is radiated from a radio communication equipment 31 and a radio communication equipment 41 receives it, a transmitter 32 of the equipment 31 is operated and a receiver 33 stops the operation for the time of 1/2fs when an electromagnetic wave of the frequency f4 is being radiated. At the same time, a receiver 43 of the equipment 41 is operated and receives the electromagnetic wave of the frequency f4, and a transmitter 42 stops an operation. In the same way, when the transmitter 42 is operated and an electromagnetic wave of a frequency f5 is radiated, the transmitter 32 stops an operation. Also, a frequency fs for switching the electromagnetic wave f4 and f5 is set to above a signal frequency of a data or a voice, etc. to be sent out. Accordingly, it does not occur that the equipme4nt 31 and 41 radiate simultaneously the electromagnetic wave, and the function for reducing a mutual influence in case the transmitter and the receiver are operated simultaneously is made unnecessary.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a wireless communication system, and particularly to a mobile communication system.

2. Description of the Related Art Conventionally, as this type of wireless communication system, a press daughter system shown in FIG. 2 and a simultaneous transmission and reception system shown in FIG. 3 have been used. The press daughter method uses one electromagnetic wave with a frequency f1, and one of the radio communication devices 11 or 12 emits a stain magnetic wave, while the other receives it at the same time, and this is manually switched alternately. It is used for communication, and 11
It is impossible for either wireless communication device to transmit and receive at the same time.

As shown in FIG. 2, the simultaneous transmission and reception method uses two waves of electromagnetic wave frequency f2D and fS, and the wireless communication devices 14 and Takumi simultaneously emit and receive electromagnetic waves at the same time.

Problems to be Solved by the Invention The simultaneous transmission and reception system shown in Figure 3 has the advantage of being able to transmit and receive at the same time compared to the breath-talk system shown in Figure 2, but on the other hand, it complicates the wireless communication device. There are drawbacks.

In wireless communication devices that use the simultaneous transmitting and receiving method, the transmitter and receiver operate simultaneously within one device, so mutual interference between the transmitter and receiver is a problem, and in order to prevent this,・It is necessary to electromagnetically shield the transmitter and receiver.

Furthermore, in mobile communication devices that often share an antenna between a transmitter and a receiver, as shown in FIG. A device 19 is required. The purpose of use of the transmitting/receiving antenna sharing device 19 is to supply the high frequency output power of the transmitter to the antenna and prevent it from entering the receiver, and at the same time to supply the weak received signal induced by the antenna to the receiver and transmit it to the transmitter. The purpose is to prevent it from entering. Generally, the power level difference between the high frequency output power of the transmitter and the received signal induced by the antenna is large and often exceeds 100 aB. Therefore, a transmitting/receiving antenna sharing device is required to have a high frequency selection ratio, and is often a large component among the components used in a wireless communication device.

The present invention has been made in order to solve the above-mentioned problems inherent in the conventional technology, and therefore, an object of the present invention is to enable a wireless communication device to alternately emit electromagnetic waves from one side and receive them at the same time. It is an object of the present invention to provide a new mobile communication system that has a simultaneous transmitting and receiving function and can constitute a compact and low power consumption wireless communication device by setting the switching frequency to be equal to or higher than the signal frequency.

Means for Solving the Problems In order to achieve the above object, a mobile communication system according to the present invention includes: a wireless communication device equipped with a transmitter and a receiver;
While the transmitter of the wireless communication device on the transmitting side is operating, the receiver stops operating, and at the same time, the receiver of the wireless communication device on the receiving side operates and the transmitter stops operating, and the wireless communication device alternates. It is characterized in that either one emits a stain magnetic wave, and the switching frequency of the electromagnetic wave is higher than the signal frequency to be transmitted.

Embodiment of the Invention Next, a preferred embodiment of the present invention will be specifically explained with reference to the drawings.

FIG. 1 shows an embodiment of the mobile communication system according to the present invention, and is a timing chart showing the operating states of a transmitter and a receiver when wireless communication devices 31 and 41 communicate.

First, let us consider the case where the wireless communication device 31 emits a magnetic wave and the wireless communication device 41 receives it. The transmitter n of the wireless communication device 31 operates and emits an electromagnetic wave with a frequency of 4, and at the same time, the receiver 43 of the wireless communication device 41 operates and emits an electromagnetic wave with a frequency of f.
After receiving the electromagnetic wave No. 4, the transmitter 42 stops operating.

Next, when the radio communication device 41 emits electromagnetic waves and the radio communication device 31 receives them, the transmitter 42 of the radio communication device 41 operates in the same manner as described above, and emits electromagnetic waves with a frequency of 5. At a time of 1, the receiver stops operating, and at the same time, the receiver of the wireless communication device 31 starts operating and receives electromagnetic waves of frequencies ij!i and f5, and the transmitter 32 stops operating.

In the case of the above operation, the switching frequency of electromagnetic waves 4 and f5 is set to 5, which is higher than the signal frequency of data, voice, etc. to be sent. According to the sampling theorem, it is possible to restore discrete data to the original continuous signal by making the sampling frequency more than twice the signal frequency.

According to the mobile communication system according to the present invention, both the wireless communication devices 31 and 41 do not emit electromagnetic waves at the same time. Therefore, since the transmitter n and the receiver o in the wireless communication device 3J do not operate simultaneously, the functions required of the transmitting/receiving antenna shared device shown in FIG. 3 are reduced.

In other words, the transmitting/receiving antenna sharing device for a wireless communication device using a mobile communication system according to the present invention does not require a function to reduce the mutual influence when the transmitter and receiver operate simultaneously.
It is sufficient to provide a function for removing unnecessary wave components from the high frequency output of the transmitter and for selecting a desired received signal from among the weak received signals induced by the antenna.

Therefore, it is possible to reduce the size of the transmitting and receiving antenna sharing device compared to the conventional simultaneous transmitting and receiving system. Also, the operating time of the transmitter and receiver according to the present invention is i compared to the operating time of a normal simultaneous transmitting and receiving system. Therefore, since the power consumption is 100, the operating time when operating on a battery is approximately doubled.

Furthermore, the temperature rise due to heat generation is suppressed to a low level, which has a great effect on reliability.

In this embodiment, a communication system using two waves of frequency 4 and f5 has been described, but the effect of the present invention is the same even if only one wave is used.

Effects of the Invention As explained above, in the mobile communication system of the present invention, the wireless communication devices alternately radiate electromagnetic waves from one side and the switching frequency is set to be equal to or higher than the signal frequency.
This has the effect of easily providing a mobile wireless communication device that has simultaneous transmitting and receiving functions and has low power consumption.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the mobile communication system according to the present invention, and is a timing chart showing the operating states of a transmitter and a receiver. FIGS. Block diagrams 1 and 4 showing the transmitting and receiving method are block diagrams of a conventional wireless communication device using the simultaneous transmitting and receiving method. 11, 12.14.15.16... Wireless communication device, 1
3... Antenna, 17... Transmitter, 18... Receiver, 19... Transmitting/receiving antenna shared device, 31.41...
・Wireless communication device, 32.42...transmitter, ah, 43.
...Receiver patent applicant NEC Co., Ltd. Agent Patent attorney Yuta Kumagai procedural amendment February 6, 1985

Claims (1)

[Claims] In a wireless communication device equipped with a transmitter and a receiver, while the transmitter of the transmitting side wireless communication device is operating, the receiver stops operating, and at the same time, the receiver of the receiving side wireless communication device operates and the transmitter A mobile communication system characterized in that the wireless communication devices stop operating, the wireless communication devices alternately emit electromagnetic waves from one side, and the switching frequency of the electromagnetic waves is higher than the signal frequency to be transmitted.