JP2020161879A - Radio communication system and central device - Google Patents

Abstract

To provide a radio communication system having an improved speech quality, and a central device thereof.SOLUTION: In a radio communication system, a central device 120 includes: a first A/D converter 122 for converting a voice signal which is input through a command operation panel into a digital signal; a first coding unit 132 for causing an output signal from the first A/D converter to be coding data; a detection unit 133 for detecting a voice level of the output signal of the first A/D converter; a first decoding unit 131 for decoding a signal received from a radio section into coding data; a first D/A converter 121 for converting an output of the first decoding unit into an analog signal; a silence detection unit 135 for detecting silence of the output of the first decoding unit; and a first changeover switch 134 for switching the coding data of the first coding unit and a signal received from the radio section as data to be transmitted to the radio section on the basis of information on the detection unit, a call press button 103, and the silence detection unit.SELECTED DRAWING: Figure 1

Description

The present invention relates to a wireless communication system including a base station and a plurality of terminal stations, and particularly relates to a technique for improving the call quality of voice data.

In a wireless communication system including a base station equipped with a central device and a plurality of terminal stations, a command desk connected to the base station and a call between one terminal station can be transmitted to another terminal station for listening. There is a function. For example, when the content of a call between a command station and an on-board station is to be heard by all on-board stations, the transmitted voice of the command station and the transmitted voice of the on-board station are combined, and the command station sends a plurality of on-board stations. It is transmitted to the station in a timely manner. In such a case, the on-board station during a call with the command station hears its own voice as a sidetone, which significantly hinders the call.

In order to solve this problem, an echo canceller is installed in the on-board station device, which is a terminal station, and in consideration of the delay time and the limitation of the voice band generated in the wireless line, a signal equivalent to the wireless line is output by a delay circuit and a bandpass filter. Technology that enables smooth communication by removing only the transmitted voice component of the own station from the signal generated, input as the reference signal of the echo canceller, received by the on-board station device from the command station which is the base station, and demodulated. (See Patent Document 1).

Japanese Unexamined Patent Publication No. 2003-018052

In train radio systems, etc., a voice codec is used to realize voice calls using wireless or wired, but when trying to add a listening function using the echo canceller described above to this voice codec, the following There is such a problem. That is, when both the command console operation panel and the on-board operation panel are in a non-call state, such as between conversations after the start of a call, the on-board reception during a call repeats a sir sound and silence, which is the background noise of the command. On the other hand, when both call at the same time, the downlink voice of the on-board call during the call is interrupted. These issues are the changeover switch in the voice codec that realizes the listening function provided in the central device when the voice level from the command panel operation panel and the voice level from the on-board operation panel are the same level. , It is thought that this is due to the fact that it is not fixed.

An object of the present invention is to solve the above-mentioned problems and to provide a wireless communication system between a base station and a plurality of terminal stations with improved call quality, and a central device thereof.

In order to achieve the above object, the present invention is a wireless communication system that realizes a voice call using a wireless line, and is a command console operation panel including a call press button and voice input by the command console operation panel. Detects the level of the output signal of the first A / D converter that converts the signal into a digital signal, the first coding unit that uses the output signal of the first A / D converter as encoded data, and the first A / D converter. Level detection unit, first decoding unit that decodes the signal received from the radio section into encoded data, first D / A converter that converts the output of the first decoding unit into analog signal, and level detection unit. As data to be sent to the wireless section based on the information of the call press button, a central device including a first changeover switch that switches between the coded data from the first coding unit and the signal received from the wireless section, and the terminal station operation panel. A second A / D converter that converts the audio signal input from the terminal station operation panel into a digital signal, a second coding unit that uses the output signal of the second A / D converter as coded data, and a radio section. A second decoding unit that decodes the received data from, a comparison unit that compares the data obtained by delaying the coded data of the output of the second encoding unit by the transmission delay time, and the received data from the radio section. A terminal station device including a second changeover switch that switches between the output of the second decoding unit and silent data based on the comparison result of the comparison unit, and a second D / A converter that converts the output of the second changeover switch into an analog signal. Provided are a wireless communication system having a configuration including, and a central device thereof.

Further, in order to achieve the above object, in the present invention, it is a wireless communication system that realizes a voice call using a wireless line, and digitally converts the command console operation panel and the voice signal input by the command console operation panel. Level detection that detects the level of the output signal of the first A / D converter that converts to a signal, the first coding unit that uses the output signal of the first A / D converter as encoded data, and the output signal of the first A / D converter. A unit, a first decoding unit that decodes a signal received from a radio section into encoded data, a first D / A converter that converts the output of the first decoding unit into an analog signal, and a first decoding unit. Based on the information of the silence detection unit that detects the output silence and the level detection unit and the silence detection unit, the coded data from the first coding unit and the signal received from the radio section are switched as the data to be transmitted to the radio section. The central device including the first changeover switch, the terminal station operation panel, the second A / D converter that converts the audio signal input from the terminal station operation panel into a digital signal, and the output signal of the second A / D converter. A second coding unit to be coded data, a comparison unit that compares the data obtained by delaying the coded data of the output of the second coding unit by the transmission delay time with the received data from the radio section, and the radio section. Based on the comparison result of the second decoding unit that decodes the received data from, the second decoding unit, the second selector switch that switches between the output of the second decoding unit and the silent data, and the output of the second selector switch are converted to analog signals. Provided is a radio communication system having a terminal station device including a second D / A converter to be converted, and a central device thereof.

According to the present invention, it is possible to provide a wireless communication system with improved call quality and a central device.

It is a figure which shows one configuration example of the wireless communication system and the central device which concerns on Example 1. FIG. The figure for demonstrating the operation outline 1 of the wireless communication system which concerns on Example 1. FIG. The figure for demonstrating the operation outline 2 of the wireless communication system which concerns on Example 1. FIG. The figure which shows the structure of the conventional train radio system. The figure for demonstrating the operation outline 1 of the train radio system of the prior art. The figure for demonstrating the operation outline 2 of the train radio system of the prior art. The figure for demonstrating the problem of the train radio system of the prior art.

Hereinafter, various embodiments for carrying out the present invention will be described with reference to the drawings, but prior to that, using a conventional wireless line, between the command console operation panel and the on-board station operation panel, with reference to FIGS. 4 to 7. An example of realizing a train listening function of a train radio system capable of voice communication and its problems will be described. The long broken line in the figure is an auxiliary line for showing the signal flow.

As shown in FIG. 4, the train radio system that enables voice communication between the command panel operation panel and the on-board station operation panel using a wireless line includes the command console operation panel 200, the centralized device 220, and the on-board station device 240. , Consists of on-board operation panel 260. The command console operation panel 200 is composed of a microphone 202 and a speaker 201, and the central device 220 is an A / D converter 222 that converts the microphone input sound from the command console operation panel 200 into a PCM signal, and an A / D conversion. A coding unit 232 that voice-codes the output signal of the device, a detection unit 233 that detects the voice level of the A / D converter output signal, and a decoding unit 231 that decodes the signal received from the radio section into PCM data. , "Coded data from the command console operation panel" and "From the wireless section" as the data to be sent to the wireless section based on the information of the D / A converter 221 that converts the decoded output into an analog signal and the detection unit 233. It is composed of a listening function switch 234 that switches "received coded data". The detection unit that detects the voice level may be called a level detection unit.

On the other hand, the on-board operation panel 260 is composed of a microphone 262 and a speaker 261. The on-board station device 240 includes an A / D converter 241 that converts microphone input audio from the on-board operation panel 260 into a PCM signal. A / D converter A coding unit 251 that voice-encodes the output signal, a storage unit 253 that stores the coded data of the coded output for the transmission delay time, the output of the storage unit 253, and reception from the radio section. Refer to the comparison unit 254 that compares the data, the decoding unit 252 that converts the received data from the wireless section into PCM data, and the comparison result of the comparison unit output, and "PCM data of the decoded output" and "silent data (silent data) It consists of an echo canceller switch 255 that switches "Mute)" and a D / A converter 242 that converts the output PCM data (silent data) into an analog signal.

The outline of the operation of the listening function in this conventional train radio system is described below. In the voice codec 230 of the central device 220, the level difference between "voice transmitted from the command panel operation panel 200" and "voice transmitted from the on-board operation panel 260 of the on-board station device 240 to be called". Compare and send a high-level signal to the wireless line. The voice codec 250 of the on-board station device 240 compares the "voice sent by the own on-board station device 240" with the "voice received from the central device 220", and if they match, the on-board operation panel 260 is displayed. The audio output is muted and muted, and if there is a mismatch, the audio received from the central device 220 is output.

FIG. 5 shows a voice path when a command voice is transmitted from the command panel operation panel 200 and a command voice is received by the on-board operation panel 260A. In the figure, since there is a command voice, the changeover switch 234 for the listening function of the central device 220 selects the command voice. On the other hand, since the comparison data of the comparison unit 154 of the on-board station device 240A does not match, it is not muted, and the instruction voice received from the central device 220 is output to the speaker of the on-board operation panel 260A.

FIG. 6 shows a voice path when voice is transmitted from the on-board operation panel 260A and the voice is received on the command panel operation panel 200 or the non-call on-board operation panel 240B. In the figure, since there is no command voice, the changeover switch 234 for the listening function of the central device 220 selects the on-board voice. On the other hand, since the comparison data of the comparison unit 154 of the on-board station device 240A matches, the mute is limited.

Compare the level difference between "voice transmitted from the command console operation panel" and "voice transmitted from the on-board operation panel of the on-board station device (on-board station device A) to be called" in the central device. Then, a high-level signal is sent to the wireless line. In each on-board station device, compare the "voice sent by the on-board station device" and the "voice received from the centralized traffic control", and if they match, mute and mute the voice output to the command panel operation panel (Mute). ), And output the voice received from the central device due to a mismatch.

The voice path when sending voice from the command panel operation panel and receiving the voice on the on-board operation panel is shown in Fig. 3, and the voice is sent from the on-board operation panel and operated on the command console operation panel or non-calling vehicle. FIG. 4 shows a voice path when receiving voice from the panel. By providing the above processing, the on-board operation panel to be called can make a call with the command console operation panel without echoing the voice transmitted by the user. In addition, the on-board operation panel for non-calls can listen to (monitor) a call between the command console operation panel and the on-board operation panel for calls.

Due to the configuration and processing of the centralized traffic control 220 described with reference to FIGS. 4 to 6, the on-board operation panel 260A to be called can make a call with the command panel operation panel 200 without echoing the voice transmitted by itself. In addition, the on-board operation panel 260B, which is the target of non-calling, can listen (monitor) the conversation between the command console operation panel 200 and the on-board operation panel 260A, which is the target of calling.

However, in the above train radio system configuration, when the command panel operation panel 200 and the on-board operation panel 260A are both in a non-call state such as during a conversation after the start of a call, the on-board operation panel 260A during a call is used. The on-board call becomes a lumpy sound by repeating a sir sound and no sound, which are background noises of the command voice of the command operation panel 200.

This is because, as shown in FIG. 7, the changeover switch 234 that realizes the listening / speaking function provided in the central device 220 is not fixedly determined, and the determination of the command voice flutters at predetermined intervals. As a result, a command and silence are switched by mute control based on the comparison result of the comparison unit 154 of the on-board station device 240A, and a buzzing sound is heard from the speaker of the on-board operation panel 260A.

Further, when the command panel operation panel 200 and the on-board operation panel 260A make a call at the same time, the downlink voice of the on-board call during the call is interrupted. This is because when the voice level from the command panel operation panel 200 and the voice level from the on-board operation panel 260A are at the same level, the changeover switch 234 that realizes the listening function provided in the central device 220 is constant. This is because the judgment of the presence or absence of the command voice flutters at multiple intervals such as 40 ms.

The first embodiment is an example of a wireless communication system in which the above-mentioned problems in the conventional system are solved and the call quality is improved, and a central device thereof. That is, it is a wireless communication system that realizes voice communication using a wireless line, and is a command console operation panel including a call press button and a first A / D that converts voice signals input by the command console operation panel into digital signals. Received from a converter, a first coding unit that uses the output signal of the first A / D converter as encoded data, a level detection unit that detects the level of the output signal of the first A / D converter, and a radio section. Radio section based on the information of the first decoding unit that decodes the signal into encoded data, the first D / A converter that converts the output of the first decoding unit into an analog signal, the level detection unit, and the call press button. As the data to be sent to, the central device including the coded data from the first coding unit and the first changeover switch for switching the signal received from the radio section, the terminal station operation panel, and the voice input from the terminal station operation panel. A second A / D converter that converts the signal into a digital signal, a second coding unit that uses the output signal of the second A / D converter as encoded data, and a second decoding that decodes the received data from the radio section. The second decoding is based on the comparison result of the comparison unit and the comparison unit that compares the data obtained by delaying the coded data of the output of the unit and the second coding unit by the transmission delay time and the received data from the radio section. A wireless communication system having a configuration including a second changeover switch for switching between the output of the conversion unit and silent data, and a terminal station device including a second D / A converter for converting the output of the second changeover switch into an analog signal, and a wireless communication system thereof. It is an embodiment of a central device.

Further, this embodiment is a wireless communication system that realizes a voice call using a wireless line, and is a first A / D that converts a command console operation panel and a voice signal input by the command console operation panel into a digital signal. Received from a converter, a first coding unit that uses the output signal of the first A / D converter as encoded data, a level detection unit that detects the level of the output signal of the first A / D converter, and a radio section. A first decoding unit that decodes a signal into encoded data, a first D / A converter that converts the output of the first decoding unit into an analog signal, and silence detection that detects the silence of the output of the first decoding unit. A central device including a first changeover switch that switches between the coded data from the first coding unit and the signal received from the radio section as data to be transmitted to the radio section based on the information of the unit, the level detection unit, and the silence detection unit. And the terminal station operation panel, the second A / D converter that converts the audio signal input from the terminal station operation panel into a digital signal, and the second code that uses the output signal of the second A / D converter as the encoded data. A comparison unit that compares the data obtained by delaying the coded data of the output of the conversion unit and the second encoding unit by the transmission delay time with the received data from the radio section, and the first decoding the received data from the radio section. Based on the comparison result of the 2 decoding unit and the comparison unit, the 2nd changeover switch that switches between the output of the 2nd decoding unit and the silent data, and the 2nd D / A converter that converts the output of the 2nd changeover switch into an analog signal. It is an embodiment of a wireless communication system including a terminal station device including the above, and a central device.

FIG. 1 is a diagram showing a configuration example of the train radio communication system of this embodiment and its central device. In the figure, as compared with the configuration of the conventional wireless communication system shown in FIG. 4, a call press button 103 is added to the command panel operation panel 100, and a silence detection unit 135 is added to the central device 120, and their outputs are switched. The point input to the switch 134 is a new configuration.

As a result, in the configuration of this embodiment, a condition for switching between on-board voice and command voice by the changeover switch 134 of the central device 120 is added, and when the call press button 103 of the command control panel 100 is pressed, there is no sound. When the detection unit 135 detects the silence of the voice codec 130, the on-board station wrapping as a listening function is turned off.

That is, in the wireless communication system of FIG. 1, the command console operation panel 100 composed of the microphone 102, the speaker 101, and the call press button 103, and the microphone input voice from the command console operation panel 100 are converted into PCM signals. The / D converter 122, the coding 132 that voice-codes the A / D converter output signal, the detector 133 that detects the voice level of the A / D converter output signal, and the signal received from the radio section. A decoding 131 that decodes to PCM data, a silence detection unit 135 that detects silence of PCM data from the decoding output, a D / A converter 121 that converts the decoded output into an analog signal, and a detection unit 133. From the newly added information of the call press button 103 and the silence detection unit 135, the data to be sent to the wireless section by the changeover switch 134 is "coded data from the command console operation panel" and "code received from the wireless section". Switch between "coded data". The on-board station device 140, which is a terminal station device, and the on-board operation panel 160, which is a terminal station operation panel, have the same configurations as the conventional system shown in FIG.

Therefore, the conventional listening function is provided, and in the central device 120, "voice transmitted from the command panel operation panel 100" and "speech transmitted from the on-board operation panel 160 of the on-board station device 140 to be called". Compare the level difference of "voice" and send a high-level signal to the wireless line. Further, in each on-board station device 140 which is a terminal station device, "voice transmitted by the own on-board station device 140" and "voice received from the central device 120" are compared, and if they match, the terminal station device The audio output to the command console operation panel 100, which is the panel, is muted and muted, and if there is a mismatch, the audio received from the central device 120 is output. As a result, in the configuration of the present embodiment, the on-board operation panel to be called can make a call with the command console operation panel without echoing the voice transmitted by the user. Further, the on-board operation panel to be non-call can listen to (monitor) the talk between the command console operation panel and the on-board operation panel to be called, and will be further described with reference to FIGS. 2 and 3. New functions and effects can be obtained.

FIG. 2 shows an outline of operations when the wireless communication system of this embodiment and its central device are simultaneously transmitted from the command panel operation panel and the on-board operation panel, and FIG. 3 shows the operation panel of the command console operation panel. The outline of the operation when both the on-board operation panels are silent is shown. In FIGS. 2 and 3, the on-board station devices 140A and 140B and the on-board operation panels 160A and 160B each show a system in two cases, but the number thereof is not limited to two. The long broken line in FIGS. 2 and 3 is an auxiliary line for indicating the signal flow.

As shown in FIG. 2, when the operator transmits voice from the command panel operation panel 100, the call press button 103 is pressed. In the central device 120, when the call press button 103 is pressed, the changeover switch 134 refers to the press information of the call press button 103 captured from the command panel operation panel 100 in addition to the conventional changeover conditions. The voice from the command panel operation panel 100 is transmitted to the wireless section. By adding this function, in the wireless communication system of this embodiment, voice is transmitted simultaneously from the command panel operation panel 100 and the on-board operation panel 160A, and when the volume levels are the same, the sound of the downlink voice is heard. The break is resolved.

Next, the silence detection in the central device 120 of this embodiment will be described with reference to FIG. As shown in the figure, the silence detector 135 of the central device 120 detects the silence of the voice data transmitted from the on-board operation panel 160A. As a method of detecting silence, for example, the output of the decoding unit 131 of the voice codec 130 is used, and the presence or absence of voice is detected using the level of background noise from the on-board operation panel 160A as a threshold value. When the silence detection unit 135 detects silence, the changeover switch 134 transmits the sound from the command panel operation panel 100 to the wireless section. By adding this function, when both the command panel operation panel 100 and the on-board operation panel 160A are in a silent state, the fluttering of the switch change is eliminated and the sound interruption of the downlink sound is eliminated.

That is, in the wireless communication system of the present embodiment, the central device 120 is newly provided with a silence detection unit 135 that detects silence of PCM data from a decoded output obtained by decoding a signal received from a radio section, and is a changeover switch. From the information of the detection unit 133, the call press button 103 of the command console operation panel, and the silence detection unit 135, the data to be transmitted to the wireless section is "encoded data from the command console operation panel" and "from the wireless section". Since the configuration is such that the received coded data is switched, it is possible to provide a wireless communication system with improved call quality.

In the above description of the examples, the train radio system has been illustrated as an example, but the present invention is not limited to the train radio system, and the general wireless communication system between the base station and the plurality of terminal stations is used. Call quality can be improved.

Further, the present invention is not limited to the above-described examples, and includes various modifications. For example, the above-described embodiment has been described in detail for a better understanding of the present invention, and is not necessarily limited to the one including all the configurations of the description.

Further, for each of the above-mentioned configurations, functions, central devices, etc., an example of realizing a part or all of them by hardware, for example, by designing a circuit has been described, but a program for realizing a part or all of them is created. Needless to say, it can also be realized.

100, 200 Command panel operation panel
101, 161, 201, 202 speakers
102, 162 microphone
103 Call press button
120, 220 Centralized traffic control
121, 142, 221, 242 Digital-to-analog converter (D / A)
122, 141, 222, 241 Analog-to-digital converter (A / D)
130, 230 voice codec (for central)
131, 231, 152, 252 Decoding section
132, 151, 232, 251 Encoding section
133, 233 (level) detector
134, 155, 234, 255 selector switch
135 Silence detector
140, 240 on-board station equipment
150, 250 voice codec (for desktop)
153, 253 Memory
154, 254 Comparison section
160, 260 Desktop operation panel

Claims (5)

A wireless communication system that realizes voice calls using wireless lines.
Command panel operation panel including call press button,
A first A / D converter that converts an audio signal input by the command console operation panel into a digital signal, a first coding unit that uses the output signal of the first A / D converter as coded data, and the first coding unit. A level detection unit that detects the audio level of the output signal of the 1A / D converter, a first decoding unit that decodes the signal received from the radio section into encoded data, and an analog signal for the output of the first decoding unit. Based on the information of the first D / A converter, the level detection unit, and the call press button, the data to be transmitted to the radio section includes the coded data from the first coding unit and the radio section. A central device that includes a first selector switch to switch the received signal,
Terminal station control panel and
A second A / D converter that converts an audio signal input from the terminal station operation panel into a digital signal, a second coding unit that uses the output signal of the second A / D converter as encoded data, and the first. A comparison unit that compares the data obtained by delaying the coded data of the output of the two coding units by the transmission delay time with the received data from the radio section, and a second decoding that decodes the received data from the radio section. A second changeover switch that switches between the output of the second decoding unit and silent data, and a second D / A conversion that converts the output of the second changeover switch into an analog signal by referring to the comparison result of the unit and the comparison unit. A terminal station device including a device,
A wireless communication system characterized by this. A wireless communication system that realizes voice calls using wireless lines.
Command panel operation panel and
A first A / D converter that converts an audio signal input by the command console operation panel into a digital signal, a first coding unit that uses the output signal of the first A / D converter as coded data, and the first coding unit. A level detection unit that detects the audio level of the output signal of the 1A / D converter, a first decoding unit that decodes the signal received from the radio section into encoded data, and an analog signal for the output of the first decoding unit. Data to be transmitted to the radio section based on the information of the first D / A converter that converts to, the silence detection unit that detects the silence of the output of the first decoding unit, and the level detection unit and the silence detection unit. As a central device including the coded data from the first coding unit and the first changeover switch for switching the signal received from the radio section.
Terminal station control panel and
A second A / D converter that converts an audio signal input from the terminal station operation panel into a digital signal, a second coding unit that uses the output signal of the second A / D converter as encoded data, and the first. A comparison unit that compares the data obtained by delaying the coded data of the output of the two coding units by the transmission delay time with the received data from the radio section, and a second decoding that decodes the received data from the radio section. A second changeover switch that switches between the output of the second decoding unit and silent data, and a second D / A conversion that converts the output of the second changeover switch into an analog signal by referring to the comparison result of the unit and the comparison unit. A terminal station device including a device,
A wireless communication system characterized by this. The wireless communication system according to claim 2.
The command panel operation panel includes a call press button, and the central device includes a silence detection unit that detects silence of the output of the first decoding unit.
The first changeover switch switches data to be transmitted to the radio section based on the information of the level detection unit, the silence detection unit, and the call press button.
A wireless communication system characterized by this. It is a central device of a wireless communication system that realizes voice calls using wireless lines.
A first A / D converter that converts an audio signal input from a command console operation panel including a call press button into a digital signal, and a first coding unit that uses the output signal of the first A / D converter as encoded data. A level detection unit that detects the voice level of the output signal of the first A / D converter, a first decoding unit that decodes the signal received from the radio section into encoded data, and the first decoding unit. Based on the information of the first D / A converter that converts the output into an analog signal, the level detection unit and the call press button, the data to be transmitted to the radio section includes the coded data from the first coding unit. A first changeover switch for switching a signal received from the radio section is included.
A centralized device characterized by that. It is a central device of a wireless communication system that realizes voice calls using wireless lines.
A first A / D converter that converts an audio signal input on the command console operation panel into a digital signal, a first coding unit that uses the output signal of the first A / D converter as encoded data, and the first A. A level detection unit that detects the voice level of the output signal of the / D converter, a first decoding unit that decodes the signal received from the radio section into encoded data, and the output of the first decoding unit into an analog signal. As data to be transmitted to the radio section based on the information of the first D / A converter to be converted, the silence detection unit that detects the silence of the output of the first decoding unit, and the level detection unit and the silence detection unit. A first changeover switch for switching between the coded data from the first coding unit and the signal received from the radio section is included.
A centralized device that features that.

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