JPS59175228A - Method and device for communication transmitting audio signal and position information signal on time-division basis - Google Patents

Abstract

PURPOSE:To secure service of good quality without any feeling of physical disorder by connecting a base station to a mobile station which moves freely within a specific wide area by a single radio circuit, and using this radio circuit to transmit a speech signal and the position information signal of the moving body alternately on time-division basis. CONSTITUTION:The mobile station 2 transmits a synchronizing signal consisting of several bits right before calling starts, and stops the transmission of a speech signal for a specific time at constant intervals of time from the end of the synchronizing signal and sends out the position information signal. The base station 9 synchronizes the reception of the position signal on the basis of said synchronizing signal. Then when the speech signal is inputted, part of it is delayed through a delay circuit for a time equal to the transmission time of the position information signal and then corrected by a spectrum correcting circuit into a spectrum distribution with the least unnaturalness. On the other hand, part of the speech signal is inputted to a level detecting circuit to detect the tendency of variation in level and its rate, and the output of the spectrum correcting circuit is controlled by the output of the level detecting circuit to maintain the tendency of speed signal level variation right before the stop of the speed signal during the speech signal stop, carrying on the operation of a talking system.

Description

[Detailed description of the invention] A single wireless line is used to connect mobile objects (mobile stations) that move freely within the country, and this wireless line is used to transmit call signals and location information signals of the mobile objects. The present invention relates to a method for alternating transmission by division and an apparatus for easily implementing this method.

Conventionally, mobile objects such as automobiles that move freely over a wide range independently measure their current position using an inertial navigation device, etc., and the measurement results are sent to the base at regular intervals as position information signals of digitized coordinate axis signals. Transmission to the base station was via a single radio link between the station and the mobile station. Furthermore, due to unstable radio wave propagation due to fading and the like, the above transmission must be repeated many times.

On the other hand, calls are transmitted whenever necessary using the so-called press-talk method. For this reason, time overlaps with the transmission of the position information signal described above. Therefore, during this time, transmission of the telephone call signal is interrupted and only the location information signal is transmitted, and after transmitting the location information signal for a certain period of time, a casual telephone call signal is transmitted.

As an actual example, when a call signal is interrupted and transmitted in this way, the number of interruptions is about 2 to 3 times per second, and the length of time for one interruption is around looms, which is sufficient.

If the interruption time is longer than about 20 to 30 milliseconds, the listener will feel uncomfortable, so the above-mentioned call interruption clearly gives a sense of discomfort and makes it difficult to hear.

The present invention has been made to solve such problems, and provides a method for reducing the above-mentioned discomfort without changing the already completed transmission system, and a device that can easily implement this method. This will be explained in detail below with reference to the drawings.

FIG. 1 is a transmission system diagram from a mobile object (mobile station) to a communication base (base station). A mobile object such as a car (4 mobile stations 2 is installed).The mobile station 2 is equipped with an inertial navigation device 3 that independently measures the current position of the mobile object 1, and an analog a digital converter 4;
A position information system circuit consisting of an encoder 5 for transmitting this converted digital signal by a transceiver and a communication system circuit 6 for inputting and outputting audio are switched by a changeover switch 7 according to a command ' of the encoder 5. It is connected to the transmitter/receiver 8.

On the other hand, the communication base is equipped with a base station 9 and a position information system circuit consisting of a transceiver 10 for communicating with mobile stations, a decoder 11 for processing position information signals, and a display 12. , and a communication system circuit including an interruption improver 13 are connected to the transmitter/receiver 10 by a changeover switch 14 that is switched by a command from the decoder 110.

FIG. 2 is a circuit diagram of the interruption improver 13, and FIG. 6 is a circuit diagram of the supplementary sound generator. The interruption improver 13 consists of a supplementary sound generator 15 and a changeover switch 16 that is linked to the changeover switch 14. Furthermore, the supplementary sound generator 15 includes a delay circuit 17, and the delay output is changed to the least unnatural state. Level detection detects level changes such as decreases and increases in the level of input signals of the delay circuit 17 and the spread torque correction circuit 18, which is composed of a low-pass filter, a band-pass filter, etc., and the rate of change thereof. circuit 19
and a level correction circuit 20 which further corrects the level of the output corrected by the spectrum correction circuit 18 based on the detected output of the level detection circuit 19.

Next, a method for eliminating the sense of discomfort caused by call interruptions in the transmission system will be explained along with the operations of each of the circuits described above. When each device in the transmission system is switched on and a call is not being made, the A contact of each changeover switch 7, 14 and 16 is the make contact. now,
When the 70 answer button is pressed to make a call, the changeover switch 7 of the mobile station 2 makes the B contact, and at the same time the encoder 5
A synchronization signal of several bits is output from. This synchronization signal passes through the transceiver 8 of the mobile station 2 and the transceiver 10 of the base station 9 and is input to the decoder 11 of the base station 9. This synchronization signal allows each part of the mobile station 2 side and the base station 9 side to operate in synchronization during the subsequent call. In case the synchronization signal is missing, there is a function to make the switch 14 a B contact if there is no synchronization signal in the carrier wave, and in this case, the first position information/Grus becomes the reference signal. .

When the synchronization signal of several bits is completed, the A contact of the changeover switch 7 of the mobile station 2 is made again, and the B contact of the changeover switch 14 of the base station 9 is made, returning to a state in which communication is possible. On the other hand, the encoder 5 of the mobile station 2 and the decoder 11 of the base station 9 simultaneously output switching signals for a fixed period of time of around 100 m5 at a rate of about 2 to 3 times per second, and only during this period, the switching signal is output. The switch 7 has a B contact, the changeover switch 14 has an A contact, and the changeover switch 16 has a B contact as a make contact. In this state, the position information of the moving object 1 measured by the inertial navigation device 3 is transferred to the analog/r-notal converter 4,
It can be placed on a wireless line through an encoder 5, a changeover switch 7, and a transceiver 8, and displayed on a display 12 through a transmitter/receiver 10, a changeover switch 14, and a decoder 11 of a base station 9.

Next, after a certain period of time of around 100 m5 has elapsed during the position information signal transmission described above, the output of the switching signals from the encoder 5 and decoder 11 is simultaneously stopped, so each changeover switch 7.
The A contacts of both 14 and 16 are made and the call state is restored. This operation is repeated two to three times per second to alternately transmit a call signal and a location information signal.

In such cases, the call signal is approximately 10 times smaller than the location information signal transmission.
The interruption is interrupted for a period of 0m5, but during this period, the interruption improver 13 shown in FIG.
This eliminates the discomfort caused by interruptions because the output is replenished.

The operation of this interruption improver 13 will be explained in more detail. Since the A contact of the changeover switch 16 is closed during normal call time, the improvement content of the interruption improver 13 has no relation to the call during this time.

However, even during this time, the content of the call is turned into a supplementary sound by the supplementary sound generator 15 and reaches the B contact, which is the break contact of the changeover switch 16.

Furthermore, the operation of the supplementary sound generator 15 will be explained. When a call signal is input, a part of it passes through a delay circuit, 17.
The signal is delayed by a time equal to the position information signal transmission time and input to the spectrum correction circuit 18. The sound fog correction circuit 18 corrects the sound fog distribution to the least unnatural (easier to hear) sound distribution and outputs it to the level correction circuit 20 . The content of this spectrum modification is that a low frequency filter is used to cut off the low frequency range, or a band and noise filter is used to cut off the low frequency range and high frequency range. On the other hand, the other part of the call signal is input to the level detection circuit 19, which detects whether the input level is decreasing, increasing, or unchanged, and if it is decreasing or increasing, the rate of change is detected and sent to the level correction circuit 20. Output. The level correction circuit 20 receives input from the spectrum correction circuit 18 and the level detection circuit 19 to delay a call while maintaining the trend of the level change of the previous call signal while the call signal is stopped during the position signal transmission time. The signal allows the communication system circuit to continue operating.

Here, a numerical explanation will be given regarding the discomfort caused by interruption of a call. Generally, the range in which a user feels less uncomfortable even if a call is interrupted is about 20 to 30 m5 or less. As in the method of the present invention, an interruption after around 100 m5 feels very strange, but the content of the call does not make much progress within this amount of time. Regarding the number of call interruptions (number of location signal transmissions), in wireless lines, it is necessary to transmit multiple times to maintain the accuracy of location information in order to avoid interference due to fading and noise.

For this purpose, even considering the shortest communication time, it is necessary to
Sending location information every three times is considered to be sufficient. Without the present invention, the call would be interrupted the same number of times, making the call uncomfortable and difficult to hear. The present invention fully resolves this problem.

As described above, according to the method and apparatus of the present invention, it is possible to ensure a comfortable and high-quality telephone call without changing the existing wireless line, and therefore the practical effects are extremely large.

[Brief explanation of the drawing]

FIG. 1 is a diagram of a transmission system from a mobile body to a communication base. FIG. 2 is a circuit diagram of an interruption improver implementing the present invention. FIG. 6 is a circuit diagram of the supplementary sound generator in the interruption improver of FIG. 2. In the figure, 2 is a mobile station, 5 is an encoder, 7 is a changeover switch, 9 is a base station, 11 is a decoder, 13 is an interruption improver, 14 is a changeover switch, 15 is a supplementary tone generator, 16 is a changeover switch, 17 1 is a delay circuit, 18 is a spectrum correction circuit, 19 is a level detection circuit, and 20 is a level correction circuit. Patent Applicant Kokusai Denki Co., Ltd. Agent Patent Attorney Toshihito Yamamoto Figure 2 13 Figure 3

Claims (1)

[Claims] 1. A communication system in which a base station and a mobile station are connected by one wireless communication line, in which the mobile station independently measures its own current position and transmits a message at regular intervals. a location information signal,
In a communication method that alternately transmits call signals transmitted at any time in a time-sharing manner, the base station side is in a state of receiving location information signals and the mobile station side is in a state of receiving call signals during times when there are no call signals. , when a mobile station makes a call, the mobile station sends out a synchronization signal consisting of several bits just before the start of the call, and from the end of this synchronization signal, it stops sending the call signal for a certain period of time and sends a location information signal. send out,
The base station side synchronizes with the synchronization signal and transmits the call signal within the same time as this sending time immediately before the location information signal sending time as a supplementary sound that has undergone audio processing and is delayed to the audio circuit during the call signal stop time. A communication method for transmitting an audio signal and a location information signal in a time-sharing manner, characterized in that the audio signal and the location information signal are inserted in a time-sharing manner, thereby preventing unnatural audio interruptions. 2. A communication method for transmitting an audio signal and a location information signal in a time-sharing manner according to claim 1, in which the audio processing of the call signal is performed in accordance with a variation in the level of the call signal.
The above-mentioned system determines any one of the decreasing tendency and decreasing rate of the level, the increasing tendency and increasing rate of the level, and the constant tendency of the level, and adjusts the level of the supplementary sound based on the determination result. A communication method that transmits audio signals and location information signals in a time-divided manner. 3. The base station and mobile station are connected by one wireless communication line, and the mobile station independently measures its current location and sends a location information signal at regular intervals and a location information signal that is sent at any time. The base station is equipped with a transmitter/receiver that alternately transmits the call signal and the call signal in a time-sharing manner, and the base station side is equipped with a transmitter/receiver that alternately receives the mobile station's location information signal and transmits and receives the call signal. In a communication device that transmits information signals in a time-division manner, a mobile station measures its current position using inertial navigation, supplies digitized position information to a transceiver,
In addition, an encoder is provided that generates a synchronization signal and a switching signal for switching between the location information system circuit and the communication system circuit, and the base station side is configured to switch between the location information system circuit and the communication system circuit based on the synchronization signal received from the mobile station side. A decoder that generates a switching signal for switching the communication system circuit in synchronization with the switching signal from the mobile station, and a communication system circuit that supplements the voice during a call interruption, are provided in the communication system circuit. The audio signal is characterized in that it is equipped with supplementary sound generating means for generating a supplementary sound by audio processing a call signal immediately before and within the same time as the transmission time during the location information signal transmission time. A communication device that transmits location information signals in a time-divided manner. 4. In the communication device that transmits the audio signal and the position information signal in a time-division manner as set forth in claim 3, the supplementary sound generating means corrects the delay circuit and the spread torque distribution of the output of the delay circuit. a level detection circuit that detects the tendency of the level change of the audio signal and its rate of change during the operation of the delay circuit; an output of the spectrum correction circuit; and an output of the level detection circuit. and a level correction circuit for creating a supplementary sound whose level has been corrected. A communication device for time-divisionally transmitting the audio signal and the position information signal. 5. A communication device that time-divisionally transmits an audio signal and a location information signal according to claim 4, wherein the spread torque correction circuit is a low-pass filter. A communication device that transmits data. 6. In the communication device that transmits an audio signal and a location information signal in a time-division manner according to claim 4, the spectrum correction circuit mI transmits the audio signal and the location information signal in a time-sharing manner using a band/matrix filter. A communication device that divides and transmits data.