JPS59107654A - Supervisory and controlling system of radio line - Google Patents

Abstract

PURPOSE:To attain radio line supervisory and control with high accuracy by transmitting a digital signal for control after applying the signal with frequency multiplexing extracting the control signal at a receiving side and transmitting the signal simultaneously with a voice signal for attining the control. CONSTITUTION:Control information is coded into a control data and also into a correcting code at an error correcting coder 2 and they are transmitted. A reproducing digital signal is decoded into the original control data at an error correcting code decoder 11 at a receiving side. The decoder 11 generates and outputs a syndrome series, and also a control data and a clock pulse synchronized with the syndrome series. A High probability measuring device 15 counts a pulse corresponding to a prescribed time length, its measured value is compared with a data Sref 17 being an estimated value of a prescribed voice transmission quality at a comparator 18, and when the measured value is larger, it is regarded as being deteriorated and the result is outputted to an estimated data output terminal 19. Thus, the radio line supervisoty control is attained with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a highly accurate wireless line monitoring and control system in a mobile communication system.

(Background Art) Conventionally, in mobile communication systems, a method of detecting the median value of the received wave level of a communication channel has been adopted as a method of monitoring the transmission quality of a voice signal after a communication channel is set. However, the accuracy of the envelope detector, which outputs a voltage proportional to the received wave level, is at such a low level that the transmission quality of the audio signal deteriorates, making it impossible to monitor and control wireless lines with high precision. There was a drawback.

In addition, after detecting that the median received wave level has fallen below a predetermined level, there is a method of transmitting control signals to perform various wireless line controls such as switching the communication channel to another wireless zone. Techniques have been employed to disconnect calls and transmit digital signals through the call channel.

However, this method has disadvantages in that instantaneous call interruptions are unavoidable and noise is generated.

Furthermore, in the method of monitoring the transmission quality of audio signals based on the received wave level, when co-channel interference occurs, the received wave level is detected as being equal to or higher than a predetermined value. Unfortunately, this method has the disadvantage that deterioration in audio signal transmission quality due to co-channel interference cannot be detected.

(Problem of the Invention) In order to eliminate these drawbacks, the present invention is characterized in that a control signal is transmitted simultaneously with the audio signal by frequency multiplexing a band-limited digital signal outside the audio signal band.
By adopting an error correction code as the digital signal code format and constantly monitoring the syndrome series generated from the error correction code, it is possible to monitor the transmission quality of voice signals. Its purpose is to perform line monitoring and control.

(Structure and operation of the invention) FIG. 1 is a configuration diagram of an embodiment of the first invention in which a band-limited digital signal is superimposed on the lower band (0 to 0.3 kHz) of an audio signal. It is.

Figure 1 (A) shows the configuration of the transmitting side, and Figure 1 (B) shows the configuration of the receiving side, where 1 is an audio input terminal, '2 is a band pass filter,
3 is an instantaneous amplitude limiter, 4 is a black filter, 5 is an analog adder, 6 is a digital signal input terminal, 7 is a code converter, 8 is a low-pass filter, 9 is a modulator, 10 is a transmitting antenna, and 11 is a receiving device. Antenna, 12 is a demodulator, 13
14 is a band pass filter, 14 is an audio output terminal, 15 is a low pass filter, 16 is a code converter, and 17 is a digital signal output terminal.

From the audio signal applied to the audio input terminal, the bandpass filter 2 extracts the 0.3 to 3 kHz components.
It is input to the instantaneous amplitude limiter 3. The instantaneous amplitude limiter 3 is
A voltage waveform higher than the modulator input voltage corresponding to a preset frequency deviation is clipped, and harmonic components generated by the nonlinear operation are removed by the scorustor filter 4.

Further, the control information is encoded into control data by an input device (not shown) and inputted to the digital signal input terminal 6. The digital signal is converted by a code converter 7 into a signal format suitable for the characteristics of the transmission path, and then band-limited by a low-pass filter 8 so as not to affect the audio band. superimposed on the signal.

The modulator 9 generates a modulated wave with a frequency shift corresponding to the input voltage, and transmits the transmission radio wave via the transmitting antenna 10. On the other hand, on the receiving side, a demodulator 12 demodulates the transmitted voltage waveform, a bandpass filter 13 extracts audio signal components, and outputs the extracted audio signal components to an audio output terminal 14. Further, the components of the digital signal are extracted by a low-pass filter 15, and after being returned to the original signal format by a code converter 16, it is output to a digital signal output terminal 17.

By adopting such a configuration as a modulation/demodulation system, it is possible to exchange control signals between a mobile station and a base station during a call without affecting the call.

FIG. 2 shows an embodiment of the second invention, in which the portion surrounded by dotted lines is a modulation/demodulation system similar to the configuration of the transmitter/receiver side shown in FIG. 2 is a control data input terminal, 2 is an error correction code encoder, 3 is an audio input terminal, 4 is a digital signal input terminal, 5 is the transmitting device shown in FIG. 1, 6 is a transmitting antenna, 7 is a receiving antenna, 8 is the receiving device shown in FIG. 1, 9 is an audio output terminal, 10 is a digital signal output terminal, 11 is an error correction code decoder, 12 is a control data output terminal, 13 is a syndrome series output terminal, and 14 is a reproduced clock output. Terminal, 15 is °"High" probability measuring device, 16
is a "High" probability measurement value output terminal.

Further, FIG. 2(C) shows an example of the configuration (6) of a system for determining whether the transmission quality of an audio signal has deteriorated below a predetermined quality, and 17 corresponds to the predetermined quality. 18 is a ratio axis device, 19 is a judgment data output terminal, and 5ref is predetermined "High" probability data.

The control information is encoded into control data by the illustrated input device and applied to the control data input terminal. The error correction code encoder 2 encodes the control data into an error correction code and sends it to the digital signal input terminal. On the other hand, the digital signal reproduced on the receiving side is decoded into original control data by an error correction code decoder 1 and output to a control data output terminal 12. Error correction code decoder 11
generates a syndrome sequence from the signal sequence of the error correction code and outputs it to the syndrome sequence output terminal 13, and also outputs a control data sequence and a clock synchronized with the syndrome sequence to the reproduced clock output terminal. 70
gh” The probability measuring device 15 counts pulses corresponding to a predetermined time length, measures how many times the syndrome series becomes “ITigh” during that time, and calculates the number as “IThigh”.
"ITight" is output to the probability measurement value output terminal 16.It
As a Ht gh I+ probability measuring device, (1) Count clock pulses and syndrome series pulses independently, and every time a predetermined number of clock pulses are counted, count the number of syndrome series pulses within that time. , obtained from the output of the counter.

(2) Provide a shift register with a number of stages equal to the number of pulses and pulses corresponding to the measurement time length, and use the shift register and up/down counter to continuously count the number of pulses in a given time length of the syndrome series. do.

For the method (2), it is possible to use Japanese Patent Application No. 54-122937.

The 'H4gh' probability measurement value of the syndrome sequence is input to the comparator 18 and is compared with the data 5ref of the II n+ gh 71 probability of the syndrome sequence corresponding to the predetermined estimate of the audio transmission quality, and is compared with the data 5ref of the II n+ gh 71 probability of the syndrome sequence corresponding to the predetermined estimate of the audio transmission quality. When the old ghll probability measurement value becomes larger than the value, it is assumed that the audio transmission quality has deteriorated below a predetermined value, and that information is output to the judgment data output terminal 19.

If an error correction code is adopted as the code format of the control signal transmitted using a band outside the voice band, and the syndrome sequence generated from it is monitored, the syndrome sequence can be detected.
The higher the "High" probability is, the lower the received wave level is, and the transmission quality of the audio signal can be estimated from the correspondence.

Figure 2 (D) shows the received wave level and the syndrome series H.
This is an example of measurement of the relationship between Hlgh II probability (carrier frequency 920 MHz, signal transmission rate 100 b/s split phase, information transmission rate 50 b/s, 6-bit burst error correction Iwadare code, digital signal modulation degree 1).
kHz, fading frequency 40 Hz). If voice transmission quality is monitored by measuring the "'High" probability of the syndrome instead of the conventional method of measuring the received wave level, high accuracy can be achieved even at reception levels below OdBμ, where the accuracy of the received wave level detector is extremely degraded. It can be seen that monitoring is possible.

FIG. 3 shows an embodiment of the third invention, in which a receiving device in which a received wave level output (envelope detection output) is added to the receiving system shown in FIG. 2 (9) (Bl) is used. Figure (Al is a configuration example of the receiving side, 1 is the receiving antenna, 2 is the configuration example in Figure 2 (B
) receiver system with a received wave level output added, 3
is an audio output terminal, 4 is a control data output terminal, 5 is a syndrome series "'High" probability measurement value output terminal, 6 is a predetermined syndrome series II r■+gh II probability data input terminal, 7 is a comparator, and 8 is a Judgment data output terminal,
9 is a received wave level output terminal, 10 is a median value detector, 11
12 is a voltage input terminal corresponding to a predetermined reception level, 13 is an analog comparator, 14 is an analog comparator output terminal, 15 is an AND gate, and 16 is an output terminal.

In addition, Vref is a voltage equivalent to a predetermined received wave level, 5ref
f is predetermined "High" probability data. Similarly to the second invention, the audio output terminal 3 and the control data output terminal 4
The audio signal, control data, and determination data are output to the determination data output terminal. Also, from the voltage corresponding to the received wave level output to the received wave level output terminal,
The median value detector 10 detects the median value within a predetermined time (10), and outputs a voltage corresponding to the median value to the median output terminal.

The voltage corresponding to the median value is the analog comparator reference voltage Vr
ef is compared with the analog comparator 13, and if the voltage corresponding to the median value is higher, a +I High j+ level is output to the analog comparator output terminal 14, and if it is the opposite, a "LOW" level is output to the analog comparator output terminal 14. Analog comparator reference voltage Vr
ef is set to a voltage corresponding to the median received wave level that is high enough to prevent pulses from appearing in the syndrome series, and is inputted from the voltage input terminal 12 corresponding to a predetermined received wave level. The output terminal 16 has a signal whose median reception level is higher than the level corresponding to Vref, and
The probability that the syndrome will be ``High'' is
If TIi gh n probability is higher than 5ref
A High' level appears. The state in which the received wave level is sufficiently high and the probability that the syndrome becomes “High” is when co-channel interference is occurring, so the present invention can eliminate co-channel interference, which was previously impossible. Monitoring becomes possible. Figure 3 (+11 is the carrier power to interference power ratio (CIR) and the syndrome "Hi"
gh” is a -i+111 regular example of the probability relationship (carrier frequency 920 MHz, interference wave frequency 920 MHz
z signal transmission rate 100 b/s split phase, information transmission rate 50 b/s, 6-bit burst error correction Iwate code, digital signal modulation depth 1 kHz, fading frequency 40 T-17,, carrier wave level median 30
dBμ).

From this figure, syndrome series II High II
From the probability measurements, the current CIR can be estimated.

(Effects of the Invention) As explained above, in the first invention, as soon as a call is influenced between a mobile station and a base station during a call,
It has the advantage that it is possible to send and receive control signals, and it is also possible to perform highly accurate wireless line monitoring and control.

In addition, in the second invention, the monitoring of the transmission quality of the audio signal, which was conventionally performed by measuring the received wave level, is
By measuring the high probability of the syndrome series, accurate monitoring becomes possible even at low received wave levels where the accuracy of the received wave level detector is extremely degraded.

Therefore, the present invention has the advantage that it is possible to perform highly accurate wireless line monitoring control.

Furthermore, in the third invention, the syndrome series
By using both "High" probability information and received wave level information, it becomes possible to monitor co-channel interference, which was previously impossible. Therefore, the present invention has the advantage that highly accurate wireless line control is possible.

[Brief explanation of drawings]

FIGS. 1(A) and (B) are diagrams showing a first embodiment of the present invention, and FIGS. 2(A), 2(B), and 2(C) are diagrams showing a second embodiment of the present invention. The configuration example of the embodiment (FIG. 2) shows the received wave level and syndrome series II Hi in the second embodiment.
Example of measurement of gh 11 probability, Figure 3 (A> is the third example of the present invention)
FIG. 3B is a diagram showing an example of measuring the IR and syndrome series "HLgh" probability in the third embodiment. In FIG. 1, 1... audio input terminal, 2... band pass filter, 3... instantaneous amplitude limiter, 4... splatter filter, 5... analog adder, 6...
Digital signal input terminal, 7... code converter, 8...
・Low pass filter, 9...Modulator, 10...Transmission antenna, 11...Reception antenna, 12...Demodulator, 13...Band noise filter, 14...Audio output terminal, 15... Mouth filter, 16... Code converter, 17... Digital signal output terminal. In FIG. 2, 1... control data input terminal, 2...
・Error correction code encoder, 3...Audio input terminal, 4...
・Digital signal input terminal, 5... Transmitting device shown in FIG. 1, 6... Transmitting antenna, 7... Receiving antenna, 8... Receiving device shown in FIG. 1, 9... Audio output terminal, 10...Digital signal output terminal, 11...
Error correction code decoder, 12... control data output terminal,
13...Syndrome series output terminal, 14...Regenerated clock output terminal, 15...°"High" probability measuring device, 16...°"High" probability measurement value output terminal,
17...Syndrome “ゝHi” corresponding to a predetermined quality
gh” probability data output terminal, 18... comparator, 19
...judgment data output terminal, 5ref...predetermined °'
"High" probability data. In Fig. 3, 1... receiving antenna, 2... second antenna.
A receiving device in which a received wave level output (envelope detection output) is added to the receiving system shown in the figure, 3... audio output terminal, 4...
・Control data output terminal, 5...Syndrome series"
High” probability measurement value output Δ1, 1 child, 6... Predetermined syndrome series "'High"' probability data input terminal, 7... Comparator, 8... Judgment data output terminal,
9... Received wave level output terminal, 0... Median value detector, 11... Median value output terminal, ]2... Voltage input terminal corresponding to a predetermined received wave level, 13... Analog comparator, 14... Analog comparator output terminal, 15...
・AND gate, 16...output terminal, 5ref...
Predetermined "'High" probability data, Vref...
This is a voltage corresponding to a predetermined received wave level. Patent applicant Nippon Telegraph and Telephone Public Corporation patent application agent Patent attorney Megumi Yamamoto (15)

Claims (1)

[Claims] (1) In a mobile radio communication system that transmits voice signals, the transmitter transmits a control digital signal by frequency multiplexing it outside the voice band, and the receiver transmits this digital signal by frequency. A wireless line monitoring and control method characterized by separating and extracting a control signal, and transmitting the control signal at the same time as an audio signal to control the wireless line. (2. In the wireless line monitoring and control system described in claim (1), an error correction code is used as the code format of the digital signal, and a syndrome sequence generated from the code is monitored. Estimate the transmission quality of the signal,
A wireless line monitoring and control method characterized by performing wireless line control based on estimation results. (3) In the wireless line monitoring and control method described in claim (2), the syndrome series and the received input electric field are simultaneously monitored, and the received input electric field is high and the transmission quality of the audio signal is high. A wireless line monitoring and control method that detects deterioration, detects the occurrence of co-channel interference, and controls the wireless line based on the results.