JP2010220146A - Voice information digital network transmission system via analog radio - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a system that improves poor hearing of voice by a delay in voice when identical voice information is transmitted to a monitor control computer from a plurality of base stations due to overreach in a base station that receive analog voice information from a mobile station via analog radio. <P>SOLUTION: The system is a system connected via at least one first base station that receives voice data transmitted from an analog radio transmitter of a mobile station, at least one second base station that includes a terminal device capable of communication with a mobile station, and a digital transmission network in which the first base station and the second base station are simplexed or multiplexed, and the second base station, when identical voice data reaches via a channel different from a receiving channel of voice data that has reached previously within a predetermined period of time from the time when the previous voice data has reached, discards the voice data through the different channel, and thereby, automatically selects one piece of voice data when a plurality of pieces of voice data is received from the same mobile station. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a network transmission system for voice information via analog radio, and in particular, automatically selects received voices at a plurality of base stations for the same voice information that occurs due to overreach, etc., and prevents voice information from being duplicated. It relates to a system for receiving information.

Conventionally, when sending voice information from a mobile station to a relay base station via analog radio and transmitting it to a remote monitoring control computer terminal, when there are a plurality of relay base stations around the mobile station, A plurality of relay base stations may receive the voice information transmitted from the mobile station (overreach).
When such overreach occurs, voice information is redundantly transmitted from the relay base station to the supervisory control computer. On the monitoring control computer side, for example, when an operator listens to voice information from a mobile station using a telephone terminal that performs a press talk type call, the voice information overlaps and arrives at the monitoring control computer side with a delay. There was a problem that the sound was echoed.

In addition, there is a technique related to a mobile communication system used for a mobile phone or the like as a technique for selecting received information and selecting a frame with less delay and better quality. In particular, when a mobile station moves between different cells, a technique of a mobile communication system that performs diversity handover is known (see Patent Document 1).
In addition, for the purpose of improving the communication quality of data transmission over the Internet, a technique related to an IP telephone in a section where the communication quality of the Internet is bad is known (see Patent Document 2).

JP 2001-285912 A JP 2005-223375 A

  According to the technique disclosed in Patent Document 1 described above, it is possible to solve a problem related to diversity handover adopted in a CDMA (code division multiple access) method that is radio section access of the third generation mobile communication system. That is, when the arrival area of the radio wave of the base station is defined as a cell, the cells are arranged so that some of them overlap each other. The base station to communicate with is changed from the base station of the source cell to the base station of the destination cell. At this time, transmission data from the mobile station is received by a plurality of base stations. Each base station adds data indicating reception quality such as reception radio wave intensity to the received data and transmits the data to the same base station controller (Radio Network Controller: RNC). The base station controller selects the received data having the best reception quality from the received data. These processes are referred to as diversity handover.

Here, as the quality information, the radio wave intensity at the time of reception and CRC (Cyclic Redundancy)
However, when analog audio information is sent from the transmission device, there are the following problems.
That is, when analog voice information is sent from the mobile station, it is necessary to determine the quality information considering the S / N ratio of the voice information in consideration of surrounding noise, noise unique to the device, and the like. . In addition, among a plurality of base stations that have received analog voice information from a mobile station, it cannot be determined whether or not they are the same voice information, and information that is added to data that each base station transmits to the base station controller The problem is that there is nothing significant.

Further, according to the technique disclosed in Patent Document 2 described above, when there is a difference in arrival time with respect to the receiving apparatus, the receiving apparatus adopts the IP packet that has arrived earliest among the arrived IP packets. Anything slower is discarded. However, such a technique is premised on digital transmission, and can be applied when it is possible to instantaneously determine whether or not the packet header is the same by an identifier or the like, such as an IP packet output simultaneously and by broadcast from a transmitting device. Is.
However, when analog voice information is sent from the transmission device, there is a problem that it is impossible to instantaneously determine whether or not they are the same by an identifier or the like as in the case of such an IP packet.

  In view of the above situation, the present invention is a base station that receives analog voice information from a mobile station via analog radio, when the same voice information is transmitted from a plurality of base stations to the monitoring control computer by overreach. An object of the present invention is to provide a system for improving poor voice listening due to voice delay.

In order to achieve the above object, an analog wireless voice digital network transmission system according to the first aspect of the present invention is provided.
1-1) at least one first base station that receives voice data transmitted from the analog radio transmitter of the mobile station;
1-2) At least one second base station including a terminal capable of communicating with the mobile station,
1-3) A system in which the first base station and the second base station are connected via a single or multiplexed digital transmission network,
1-4) The second base station transmits the same voice data (delayed voice data) for a predetermined time from the first arrival time via a channel different from the reception channel of the voice data that has arrived first (first arrival voice data). When a plurality of audio data from the same mobile station are received, one audio data can be automatically selected by discarding audio data of different channels when arriving in
The above 1-1) to 1-4).

  According to this configuration, in the base station that receives the analog voice information from the mobile station via the analog radio, the same voice information is connected from the plurality of base stations to the base station controller that is the second base station by overreach. When transmitted to a supervisory control computer, it is possible to improve poor voice listening due to voice delay.

  That is, with this configuration, even when voice information is redundantly transmitted from the relay base station that is the first base station to the monitoring control computer that is the second base station, it is the second base station. On the monitoring control computer side, for example, even when an operator listens to voice information from a mobile station using a telephone terminal that performs a press talk-type call, it is possible to avoid the echo from appearing in the voice.

Here, the determination as to whether or not the audio data is identical is made by means for determining audio data having the same identity, which will be described later.
In addition, as the predetermined time, an appropriate time is set according to the scale and conditions of the system such as 0.5 seconds and 1 second, for example.
The single or multiplexed digital transmission network includes both a general-purpose network such as the Internet protocol network (IP network) and a dedicated network for military use.

As described above, when analog voice information is transmitted from the mobile station, it is necessary to determine the quality in consideration of the S / N ratio of the voice information in consideration of the peripheral noise and the noise peculiar to the device as the quality information. There is. This is due to the fact that a unique identifier cannot be added to analog voice information, unlike when digital voice information is transmitted from a mobile station.
That is, when digital voice information is transmitted from a mobile station, a unique identifier can be added to the digital voice information, so that a plurality of first base stations receive the same digital voice information from the same mobile station. However, it is possible to easily grasp that the digital voice information is the same in the entire system using a unique identifier.

  On the other hand, when analog voice information is transmitted from a mobile station, it is difficult to add a unique identifier to the analog voice information, and the same analog voice information from the same mobile station at a plurality of first base stations. Is received, it is difficult to grasp that the analog audio information is the same in the entire system. For this reason, it cannot be determined whether or not the plurality of first base stations that have received the same analog voice information from the same mobile station are the same analog voice information. It is transmitted as independent single voice information to the base station control apparatus which is the second base station.

  The present invention determines whether a plurality of analog voice information arriving within a predetermined time is identical to the base station controller which is the second base station, and uses the first one to obtain effective voice information. And avoiding voice echo due to voice delay due to overreach and improving poor voice listening.

An analog wireless voice digital network transmission system according to the second aspect of the present invention is
2-1) at least one first base station that receives voice data transmitted from the analog radio transmitter of the mobile station;
2-2) at least one second base station comprising a terminal capable of communicating with the mobile station,
2-3) A system in which the first base station and the second base station are connected via a digital transmission network in which the first base station and the second base station are multiplexed or multiplexed.
2-4) The second base station receives the same voice data (delayed voice data) for a predetermined time from the first arrival time via a channel different from the reception channel of the voice data that has arrived first (first arrival voice data). When a plurality of pieces of voice data from the same mobile station are received, one voice data can be automatically selected by selecting voice data having the largest S / N ratio when arriving in
The above-mentioned 2-1) to 2-4).

  According to this configuration, as in the first aspect described above, in the base station that receives the analog voice information from the mobile station via the analog radio, the same voice information is received from the plurality of base stations by the overreach. When transmitted to a supervisory control computer connected to a base station control apparatus that is a station, it is possible to improve poor voice listening due to voice delay.

The present invention determines whether or not a plurality of analog audio information arriving within a predetermined time is identical to a base station control device, which is a second base station, and has the highest S / N ratio. By selecting and using the data, it is intended to improve poor voice listening due to voice delay due to overreach.
Here, the identification processing based on the S / N ratio will be described later. In the supervisory control computer connected to the base station controller that is the second base station, in the case of the same voice information, it becomes possible to hear a clearer voice.

Here, in the analog wireless voice digital network transmission system according to the first aspect or the second aspect,
The means for distinguishing voice data with the same
a) calculating the frequency spectrum of the first voice data and the frequency spectrum of the delayed voice data;
b) normalizing the input level of each frequency spectrum;
c) calculating a correlation value between the frequency and amplitude of a predetermined voice band of each frequency spectrum;
d) discriminating audio data having a correlation value equal to or higher than a predetermined threshold as identical audio data;
It is comprised from said a) -d).

  Here, the spectrum of the voice band is a spectrum of sound waves in a band of 300 to 3400 Hz, which is a voice band that can be heard by humans. The S / N ratio between the spectrum in the voice band and the spectrum outside the voice band is calculated by processing sound waves in the 300 to 3400 Hz band as a signal of voice information, and sound waves outside the 300 to 3400 Hz band as noise. This is for calculating the S / N ratio. The S / N ratio is generally a logarithm of the amount of noise (N) with respect to the signal (S), and is used when representing the performance of an electric circuit such as an amplifier. The output level (signal level) when the reference signal is input is expressed in dB (decibel) with respect to the output level (noise level) when there is no input. The larger the value of dB, the lower the noise and the higher the quality of the signal.

  Therefore, if the S / N ratio between the spectrum in the voice band and the spectrum outside the voice band is calculated, the S / N ratio between the spectrum in the voice band where the voice information exists and the spectrum outside the voice band where the noise other than the voice information exists. Is obtained. When the S / N ratio is small, the voice information is greatly affected by noise. As described above, humans have characteristics such as auditory psychology, and if there is a loud noise sound, it is impossible to perceive the presence or absence of a sound with a small frequency around it. It is determined that the voice information cannot be notified.

  Further, when there is a signal that becomes noise in the signal spectrum of the voice band, the S / N ratio of the original sound spectrum in the voice band is taken. A sound with a high S / N ratio is a sound with high clarity (clear sound).

  There are two types of noise. Intermittent noise and noise that enters at a constant frequency. If the S / N ratio is small and there is noise, the voice information cannot be normally notified to the surroundings.

In the analog wireless voice digital network transmission system,
e) calculating the S / N ratio of the spectrum of the voice band and the spectrum outside the voice band in each frequency spectrum;
f) When the correlation value is equal to or greater than a predetermined value and the S / N ratio is equal to or greater than the predetermined value, the audio data is determined to be identical.
It is a more preferable aspect that the above-mentioned e) to f) are constituted.

  According to the present invention, in a base station that receives analog voice information from a mobile station via analog radio, when the same voice information is transmitted from a plurality of base stations to the supervisory control computer by overreach, voice due to voice delay is transmitted. This has the effect of improving the hearing loss.

Analog wireless voice digital network transmission system (1) Analog wireless voice digital network transmission system (2) Analog wireless voice digital network transmission system explanatory diagram (3) Processing flow for determining the identity of analog audio information in a transmission device

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The scope of the present invention is not limited to the following examples and illustrated examples, and various changes and modifications can be made.

FIG. 1 shows a system configuration diagram of an analog wireless voice digital network transmission system of the present invention.
The system of FIG. 1 includes mobile devices (M1 to M4), first base stations (S1 to S4), and transmission devices (10, 20, 30, and 4) connected to the first base stations (S1 to S4) from the left. 40), IP network (Internet protocol network) 100, 200, second base station 60, and supervisory control computer 62 connected to the second base station, a telephone terminal (hereinafter referred to as a remote control) that performs a press talk type call. 61).

  The IP network is duplicated, and consists of a regular system (A system) 100 and a standby system (B system). The first base stations (S1 to S4) are equipped with antennas (12, 22, 32, 42), respectively, and exchange voices with the mobile stations (M1 to M4) wirelessly. In addition, the transmission device 10 is provided with an input / output terminal 14 for exchanging data with the first base station, a speaker 15, a microphone 16, and an I / F unit (17a, 17b) with an IP network, and a network cable. (18a, 18b) (the same applies to the transmission devices 20, 30, 40).

  The second base station 60 is provided with an I / F unit (67a, 67b) for the IP network, and is connected to a network cable (68a, 68b). The monitoring control computer 62 connected to the second base station 60 monitors the device status of the entire system, and when voice is sent from the mobile station, the history of the voice information (voice reception). (Date and time, voice receiving source) is stored and displayed on the display. The remote controller 61 connected to the second base station 60 includes a telephone 63, a speaker 64, and a lighting or blinking button 65 for switching the press talk.

In FIG. 1, analog voice information of mobile M1 is wirelessly sent to the first base station S1 (13), and the voice information is converted into a digital voice signal by the transmission device 10, packet-divided, A state in which the second base station 60 is reached via the IP network 100 is shown. Similarly, the mobile M2 analog voice information is wirelessly sent to the first base station S2 (23), the voice information is converted into a digital voice signal by the transmission device 20, and is divided into packets, and the A-system IP network. The second base station 60 is reached via 100. The same applies to the mobile M3 and the mobile M4.
In the state of FIG. 1, no overreach has occurred.

  Next, the case where overreach occurs will be described with reference to FIG. In FIG. 2, attention is focused only on the mobile station M3. The analog voice information transmitted from the mobile station M3 is received by the three first base stations (S2 to S4) (33a, 33b, 33c). In the first base station S 2, the voice information is converted into a digital voice signal by the transmission apparatus 20, packet-divided, and reaches the second base station 60 via the A-system IP network 100. In the first base station S 3, the voice information is converted into a digital voice signal by the transmission device 30, divided into packets, and reaches the second base station 60 via the A-system IP network 100. Yes.

  On the other hand, in the first base station S4, there is a failure in the I / F portion with the A-system IP network (for example, the cable 48b is disconnected), and the second base station 60 passes through the B-system IP network 200. Has reached.

In such a case, three audio signals are input to the second base station 60. Each audio signal has a transmission delay due to a packet delay and a different IP network. In the second base station 60, since the three pieces of voice information that have arrived exist within one second of the preset threshold value, whether or not the voice information is duplicated by checking the identity using the waveform pattern of those frequencies. Is determined.
All duplicate audio information is discarded except for the first one that arrives. At this time, only the overlapping waveform pattern of the sound that arrived within a certain time is discarded, and when the sound information is received again outside the certain time, the sound information is discarded as having been sent again It remains without being.

  The above system may be further expanded. For example, as shown in FIGS. 1 and 2, the first base station may be further expanded (50, 51, 52). In addition, as shown in FIG. 3, four first base stations (S1, S2, S3, S4) and four second base stations (60, 70, 80, 90) are duplicated. A system connected to the IP network (100, 200) may also be used. In FIG. 3, the maintenance terminal 300 is connected to the IP network.

The transmission apparatus 60 connected to the second base station includes a CPU, a RAM, and a ROM memory that are responsible for determining the identity of analog audio information. In addition, an IP interface I / F or I / O controller of an external interface that can input voice information and an external trigger signal is provided.

FIG. 4 shows a process for determining the identity of analog audio information in the transmission apparatus.
(Process 1) A comparison process is performed when the input volume level of the signal spectrum of the analog audio information is equal to or higher than a predetermined threshold (input level determination step; S11).
If the input volume level is smaller than the predetermined threshold value, it is determined that the input volume level is not sufficiently notified to the surroundings.

(Process 2) The signal spectrum of the analog audio information is normalized (normalization step; S12).
The reason for normalizing is, for example, to compare only the signal spectrum components without being affected by the difference in level of the radio that is the source of the analog audio information.

(Process 3) A correlation value between the frequency and amplitude of a predetermined voice band and the frequency and amplitude of the analog voice information in the signal spectrum of the analog voice information is calculated (correlation calculation step; S13).
Of the signal spectrum of analog voice information, the frequency and amplitude of a predetermined voice band are processed. Noise in the surrounding environment of the mobile station (track noise, wind sound, human cheer, airplane sound, noise, squeal Etc.) to eliminate background sounds.

  Specifically, in the signal spectrum of two signals, the correlation function between the frequency and amplitude of the voice band is calculated, and the similarity between the two signals is digitized. Signals having a large correlation function value are similar to each other.

  Here, the voice band refers to a frequency band of 50 Hz to 10 KHz. Within this band range, particularly in the case of normal voice, it exists in the 300 Hz to 3400 Hz band. The frequency range of the voice band is a parameter that can be tuned in the device of the present invention.

(Process 4) The S / N ratio between the spectrum of the voice band and the spectrum outside the voice band in the analog voice information and the S / N ratio of the original sound spectrum in the voice band are calculated (S / N ratio calculation step; S14).
By taking the S / N ratio between the signal spectrum in the voice band and the signal spectrum outside the voice band, a sound with a high S / N ratio is regarded as a sound with high intelligibility.
Further, when there is a signal that becomes noise in the signal spectrum of the voice band, the S / N ratio of the original sound spectrum in the voice band is taken, and the one having a high S / N ratio is determined as a sound with high clarity.

  INDUSTRIAL APPLICABILITY The present invention is useful as a voice notification device such as a wide area monitoring system that uses a business radio or a disaster prevention system that uses a disaster prevention radio.

10, 20, 30, 40, 50, 60, 70, 80, 90 Transmission device 11, 21, 31, 41, 51 Analog radio receiver 12, 22, 32, 42, 52 Analog radio antenna 15, 25, 35, 45 Speaker 16, 26, 36, 46 Microphone 61, 71, 81, 91 Remote control terminal (press talk type call terminal)
62, 72, 82, 92 Monitoring monitor 100, 200 Digital communication network 300 Maintenance computer M1-M4 Mobile station

Claims (4)

At least one first base station that receives voice data transmitted from an analog wireless transmitter of a mobile station, at least one second base station comprising a terminal capable of communicating with the mobile station, and the first A base station connected to the second base station via a single-layer or multiplexed digital transmission network,
The second base station receives identical voice data (delayed voice data) within a predetermined time from the first arrival time via a channel different from the reception channel of the voice data that has arrived first (first arrival voice data). An analog wireless voice digital network transmission system capable of automatically selecting one voice data when receiving a plurality of voice data from the same mobile station by discarding voice data of different channels . At least one first base station that receives voice data transmitted from an analog wireless transmitter of a mobile station, at least one second base station comprising a terminal capable of communicating with the mobile station, and the first A base station connected to the second base station via a single-layer or multiplexed digital transmission network,
The second base station receives identical voice data (delayed voice data) within a predetermined time from the first arrival time via a channel different from the reception channel of the voice data that has arrived first (first arrival voice data). In this case, by selecting audio data having the largest S / N ratio, one audio data can be automatically selected when a plurality of audio data from the same mobile station is received. Digital network transmission system.   The identical voice data discriminating means calculates the frequency spectrum of the first voice data and the frequency spectrum of the delayed voice data, normalizes the input level of each frequency spectrum, and determines a predetermined voice of each frequency spectrum. 3. The analog wireless voice digital network according to claim 1, wherein a correlation value between a frequency and an amplitude of a band is calculated, and the correlation value is equal to or greater than a predetermined threshold value and is determined as voice data having the same identity. Transmission system. The same is true when the S / N ratio of the spectrum of the voice band and the spectrum outside the voice band in each frequency spectrum is calculated, and the correlation value is greater than or equal to a predetermined value and the S / N ratio is greater than or equal to the predetermined value. 4. The analog wireless voice digital network transmission system according to claim 3, wherein the voice data is discriminated from voice data having characteristics.