JPH0758721A - Multiple transmission system - Google Patents

Abstract

PURPOSE:To provide a multiple transmission system which can multiplex in time division and transmit analog information of two channels, facilitates demodulation, and enables highly functional multiplex transmission. CONSTITUTION:One-bit predictive finite-difference modulation is imposed on the two pieces of analog information by modulating means 1 and 2, an NRZ/RZ converting means 3 generates a positive-polarity RZ signal from one modulation output signal, and an NRZ/RZ converting means 4 generates a positive-polarity RZ signal from a signal obtained by delaying the other modulation output signal by a half bet; and a positive/negative polarity inverting means 5 performs inversion to generate a negative-polarity RZ signal and a composing means 6 composes a ternary signal of the positive-polarity RZ signal and negative-polarity RZ signal and sends the composite signal. Positive/negative discriminating means 7 and 8 separates the positive-polarity RZ signal and negative-polarity RZ signal from the received ternary signal and a demodulating means 9 demodulates the positive-polarity RZ signal to generate analog information; and a positive/negative polarity inverting means 10 inverts the negative- polarity RZ signal to generate a positive-polarity RZ signal, which is demodulated by a demodulating means 11 to generate analog information, thus reproducing the two pieces of analog information.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multiplex transmission system capable of time-division-multiplexing and transmitting 2-channel analog information.

With the progress of advanced information technology in recent years,
A multiplex transmission system is required in order to cope with the quantitative expansion and high functionality of transmission information. The present invention provides a multiplex transmission system capable of time-division-multiplexing and transmitting 2-channel analog information, easy demodulation, and capable of high-performance multiplex transmission.

According to the multiplex transmission system of the present invention, two independent information can be transmitted to one transmission line in a subscriber line, an indoor telephone line, a speaker of an audio device, a connection line of an earphone, or the like. At this time, since all the transmission qualities including the delay time are similar, it is possible to provide a multiplex transmission system suitable for highly functional information transmission such as stereo communication.

[0004]

2. Description of the Related Art In order to transmit two pieces of analog information such as voice and video which are different from each other through one transmission line, the transmitting side multiplexes the two pieces of information by some means to create a transmission signal and the receiving side. Then, it is necessary to accurately separate the original two pieces of information from the transmitted signal.

Therefore, as a multiplexing method, by dividing the frequency domain and allocating the respective information,
There are used a frequency division multiplex transmission method of multiplexing and transmitting and a time division multiplex transmission method of multiplexing and transmitting by dividing each time domain and allocating respective information.

FIG. 4 is a block diagram showing an example of the configuration of the frequency division multiplex transmission system. The operation of the frequency division multiplexing transmission system will be described below with reference to FIG.

At the transmitting side, two pieces of analog information consisting of different audio or video are input to the analog inputs 41, 4
5 are led to balanced modulators (MOD) 42 and 46, respectively. The MODs 42 and 46 include carrier wave oscillators (C.OS).
C) Since the carrier wave from 44 is applied, each analog signal is modulated to generate a modulated wave including sidebands above and below the carrier wave. Bandpass filter (BPF) 4
3, 47 generate a signal composed of two single sideband amplitude-modulated waves by passing one side of the lower sideband and passing the other side of the upper sideband. This signal is sent to the transmission line.

On the receiving side, the signal from the transmission line is
They are led to band pass filters (BPF) 48 and 53, respectively.
Corresponding to the BPFs 43 and 47 on the transmission side, one of the BPFs 48 and 53 passes the lower sideband of the original modulated wave, and the other passes the upper sideband of the original modulated wave. To be separated. Reference numerals 49 and 54 denote demodulators (DEMs) each composed of a balanced modulator, and carrier wave oscillators (C.OS).
C) 52 from the sender C.C. By applying a carrier wave having the same frequency as that of the OSC 44, each single sideband amplitude modulation wave is demodulated. Therefore, by removing the carrier wave through each of the low pass filters (LPF) 50 and 55, an analog output can be obtained. Two original analog information can be obtained at 51 and 56.

FIG. 5 is a block diagram showing an example of the structure of the time division multiplex transmission system. The operation of the time division multiplex transmission system will be described below with reference to FIG.

On the transmitting side, two pieces of analog information consisting of different audio or video are input to the analog inputs 61, 6
9 to pulse amplitude modulators (MOD) 62 and 70, respectively
Be led to. The MODs 62 and 70 include a main oscillator (MO
SC) 65 192kbps transmit clock pulse,
1/3 frequency divider (DIV) 67 divides the frequency by 3 to 1/8
8 kb obtained by dividing frequency by frequency divider (DIV) 68 by 8
Since ps sampling pulses have been applied, each analog signal is modulated to produce a modulated signal.

Next, the modulated signal is an encoder (COD) 6
Guided to 3,71. COD 63, 71 has DIV6
Since the 64 kbps digit pulse from 7 is applied, 8-bit encoding is performed with the quantization level as a unit to generate a pulse code modulation (PCM) signal. This PCM signal is transmitted by a transmission signal distributor (S.SMP) 64,7.
2, but S. The SMPs 64 and 72 include M.S. OS
Since the 192 kbps transmission clock pulse from C65 is applied, the PCM signal is output in 1/3 time allocation.

In this case, the PCM signal from the COD 63 is assigned a second time of 1/3 of the time, and the CO
The PCM signal from D71 is assigned the third time of the 1/3 time. The first of the 1/3 times is the M.I. Synchronous pulse generator (S.SYNC) 6 from the 192 kbps transmission clock pulse obtained by OSC65
6 is assigned to the sync pulse. The pulse train thus obtained is sent to the transmission line.

On the receiving side, the pulse train from the transmission line is guided to the received signal classifiers (R.SMP) 73 and 81 and the synchronization extractor (R.SYNC) 77. R. The SYNC 77 extracts a synchronization pulse from the pulse train, and synchronizes with the main oscillator (M.OSC) 78, the 1/3 frequency divider (DIV) 79, and the 1/8 frequency divider (DIV) 80. .

R. In the SMPs 73 and 81, the pulse train is M.M. The 192 kbps received clock pulse synchronized from OSC78 separates into 3 series, and 2 series PC
The M signals are extracted, and the decoders (DEC) 74 and 8 are respectively extracted.
Lead to 2. The DECs 74 and 82 decode the PCM signal and generate a PAM signal. The PAM signal is a demodulator (D
EM) 75, 83 demodulated by analog output 7
An analog signal corresponding to the original two pieces of analog information is obtained at 6, 84.

[0015]

In the conventional frequency division multiplex transmission system, since the frequency domain is divided and each information is assigned, the frequency band is different for each information.
Therefore, since the transmission delay time is different, there is a problem that it is not suitable for stereo communication.

In the conventional time division multiplex transmission system, the time domain is divided and each piece of information is assigned,
There is a problem in that it is necessary to add a synchronization pulse on the transmitting side and extract the synchronization pulse on the receiving side, which complicates the circuit configuration.

The present invention is intended to solve the problems of the prior art as described above, and in the multiplex transmission system,
The transmission delay time does not differ for each information to be multiplexed, and it is not necessary to add redundancy such as addition and extraction of synchronization pulse for multiplexing and separation. Has an aim.

[0018]

FIG. 1 shows the basic configuration of the present invention. According to the present invention, first and second modulation means 1 and 2 for performing pre-measurement difference modulation of 1 bit for two analog information respectively, and a first RZ signal for generating a positive polarity RZ signal from one modulation output signal. A second NRZ / R converting unit 3 and a second NRZ / R that generates a second positive polarity RZ signal from the signal obtained by delaying the other modulation output signal by half a bit.
Z conversion means 4 and first positive / negative polarity inversion means 5 for inverting the second positive polarity RZ signal to generate a negative polarity RZ signal.
And a synthesizing means 6 for synthesizing the positive polarity RZ signal and the negative polarity RZ signal to generate a ternary signal.
First and second positive / negative discriminating means 7 and 8 for transmitting the ternary signal and separating the positive RZ signal and the negative RZ signal from the received ternary signal, respectively, and the positive and negative identifying means 7 and 8. First to demodulate the RZ signal to generate first analog information
Demodulation means 9 and the negative polarity RZ signal are inverted to the second
The second positive / negative polarity inversion means 10 for generating the positive polarity RZ signal and the second demodulation means 11 for demodulating the second positive polarity RZ signal to generate the second analog information. In preparation for this, the original two pieces of analog information are reproduced respectively.

[0019]

On the transmitting side, the first and second modulation means 1 and 2 respectively perform 1-bit premeasurement differential modulation on two pieces of analog information, and the first NRZ / RZ conversion means 3 A positive polarity RZ signal is generated from the modulated output signal of the above, and the second NRZ / RZ conversion means 4 generates a second positive polarity RZ signal from the signal obtained by delaying the other modulated output signal by half a bit. , First positive / negative polarity reversing means 5
Then, the second positive polarity RZ signal is inverted to generate the negative polarity RZ signal. Then, the synthesizing means 6 synthesizes the positive polarity RZ signal and the negative polarity RZ signal to generate and transmit a ternary signal.

On the receiving side, the first and second positive / negative discriminating means 7 and 8 separate the positive RZ signal and the negative RZ signal from the received ternary signal. And the first
Demodulation means 9 demodulates the positive polarity RZ signal to generate the first analog information, and second positive / negative polarity inversion means 10 inverts the negative polarity RZ signal to generate the second positive polarity RZ signal.
A Z signal is generated, and the second demodulation means 11 demodulates the second positive RZ signal to generate second analog information.

Therefore, according to the present invention, two analog information are encoded, multiplexed and transmitted from the transmitting side, and the multiplexed signals are separated and demodulated at the receiving side to obtain the original two analog information. Can be played.

[0022]

2 is a block diagram showing the configuration of an embodiment of the present invention, in which 21 and 26 are 2-channel analog inputs, and 22 and 27 are modulators for performing pre-measurement differential modulation of 1 bit ( ΔMOD), 23 and 28 are NRZ (Non Return to Ze)
ro) signal is converted to a positive polarity RZ (Return to Zero) signal by a code converter (NRZ / RZ CNV), and 24 is a clock generator (CLK G) that generates a transmission clock pulse.
EN) and 25 are inverting circuits (I
NV), 29 is a positive / negative polarity inverter (+/- CN that inverts the polarity of the positive polarity RZ code to generate a negative polarity RZ signal.
V) and 30 are synthesizers (MIX) for synthesizing the positive polarity RZ signal and the negative polarity RZ signal, and these compose the transmitting side.

Reference numeral 31 is a positive / negative discriminator (+ SEP) for separating and extracting the positive polarity digital signal, 32 and 36 are demodulators (ΔDEM) for demodulating the positive polarity digital signal, and 33, 3
Reference numeral 7 is an analog output, 34 is a positive / negative discriminator (-SEP) for separating and extracting a negative polarity digital signal, and 35 is a positive / negative polarity inverter (-SEP) for inverting the positive / negative polarity of the negative polarity digital signal.
/ + CNV), which constitute the receiving side.

FIG. 3 is a time chart showing signals of respective parts in the embodiment of FIG. 2 for explaining the operation of the multiplex transmission system of the present invention. (a) is the analog signal (A) at the analog input 21, (b) is the premeasured differential modulation (delta modulation) output at the output of the ΔMOD 22, and (c) is N
RZ / RZ CNV23 and + SEP31 outputs positive polarity RZ signal output, (d) is transmit clock pulse,
(e) is the analog signal (B) at the analog input 26,
(f) is the delta modulation output at the output of ΔMOD27,
(g) Inverted clock pulse at the output of INV25,
(h) is the positive polarity RZ signal output at the output of NRZ / RZ CNV28, (i) is +/- CNV29 and -SE
The negative polarity RZ signal output at the output of P34, (j) is MI
Multiplexed output at the output of X30, (k) is-/ + CN
Positive polarity digital signal at V35 output, (l) is reproduced analog signal (A), (m) at analog output 33
Is a reproduced analog signal (B) at the analog output 37. Hereinafter, a detailed description will be given based on FIGS. 2 and 3.

On the transmitting side, analog signals (A) and (B) [(a), (e)] consisting of two different audio or video images, etc.
] Is from the analog inputs 21 and 26 to ΔMOD 22 and 2
Guided to 7. In ΔMOD22 and 27, CLK GE
N24 transmit clock pulses (d) are used to perform 1-bit pre-measured differential modulation on the analog input signal to produce delta modulated outputs (b), (f). The 1-bit pre-measurement difference modulation determines whether or not there is a difference equal to or more than a certain constant value (quantization level) when the input signal level is compared with the amplitude value one bit before,
It is represented by digital signals 1 and 0, and is also called delta modulation.

The modulated signal is NRZ / RZ CNV23,
Guided to 28. NRZ / RZ CNV23 is CLK
By applying the transmission clock pulse (d) from the GEN24, the R of the duty of 50% is changed from the NRZ waveform.
The code is converted into a Z waveform to generate a positive polarity RZ signal output (c). NRZ / RZ CNV28 is CLK GEN24
Transmit clock pulse (d) from INV25 through 1,
By applying an inverted clock pulse (g) with the polarity of 0 inverted, R with a duty of 50% is calculated from the NRZ waveform.
A Z-waveform is sign-converted to generate a positive polarity RZ signal output (h), and further converted into a negative polarity RZ signal with a duty of 50% by +/- CNV 29 to generate a negative polarity RZ signal output (i). . Here, the transmission clock pulse in which the polarities of 1 and 0 are inverted, the positive RZ signal output (h) from the NRZ / RZ CNV 28 is converted into 1/2 bit (duty 5).
It is delayed by 0% (corresponding to 0%) to prevent the positive RZ signal output (c) from the NRZ / RZ CNV 23 from temporally colliding.

Positive polarity R from NRZ / RZ CNV23
Z signal output (c) and negative polarity R from +/- CNV29
Z signal output (i) is combined in MIX30,
It produces a multiplexed output (j) consisting of a digital signal having positive, zero, and negative three values. The thus obtained ternary pulse train is sent out to the transmission line.

On the receiving side, the pulse train input from the transmission line is separated into a positive-polarity signal component and a negative-polarity signal component by + SEP31 and -SEP34. The same positive polarity digital signal as in c) and the same negative polarity digital signal as the transmission side negative polarity RZ signal output (i) are extracted. + SEP31
And -SEP34 are, for example, simply a diode connected in the forward direction and a diode connected in the reverse direction,
It can be easily realized.

The extracted negative polarity digital signal is −
The positive / negative polarity is inverted by the / + CNV 35 and converted into a positive digital signal (k) which is the same as the positive RZ signal output (h) on the transmitting side. The digital signal from the + SEP 31 and the digital signal from the − / + CNV 35 are demodulated by the demodulators (ΔDEM) 32 and 36, and the original analog signals (A) and ( The reproduced analog signal (A) (l) and the reproduced analog signal (B) (m) corresponding to B) are generated. The ΔDEMs 32 and 36 can be easily realized by, for example, an integrator.

[0030]

As described above, according to the present invention, two analog signals composed of different audio and video are encoded and multiplexed at the transmitting side and transmitted, and separated and decoded at the receiving side. And information can be played.

In the multiplexing system of the present invention, two analog signals are coded and multiplexed by the same configuration and processing, so that there is no difference in transmission delay time.
Further, since one signal is a positive polarity digital signal and the other signal is a negative polarity digital signal, there is an advantage that a multiplex transmission system can be configured without requiring a redundant function such as addition of a synchronization pulse or synchronization extraction. is there.

[Brief description of drawings]

FIG. 1 is a diagram showing a principle configuration of the present invention.

FIG. 2 is a block diagram showing a configuration of an exemplary embodiment of the present invention.

FIG. 3 is a time chart showing signals of respective parts in the embodiment of FIG.

FIG. 4 is a block diagram showing an example of a configuration of a frequency division multiplex transmission system.

FIG. 5 is a block diagram showing an example of a configuration of a time division multiplex transmission system.

[Description of Reference Signs] 1 modulation means 2 modulation means 3 NRZ / RZ conversion means 4 NRZ / RZ conversion means 5 positive / negative polarity inversion means 6 combining means 7 positive / negative identification means 8 positive / negative identification means 9 demodulation means 10 positive / negative polarity inversion means 11 demodulation means

Claims (1)

[Claims] 1. One for each of two pieces of analog information
First and second modulation means (1, 2) for performing pre-measurement difference modulation of bits, and first NRZ / RZ conversion means (3) for generating a positive polarity RZ signal from the one modulation output signal A second NRZ / RZ conversion means (4) for generating a second positive polarity RZ signal from a signal obtained by delaying the other modulated output signal by half a bit; and inverting the second positive polarity RZ signal. And a first positive / negative polarity inverting means (5) for generating a negative polarity RZ signal, and a synthesizing means (6) for synthesizing the positive polarity RZ signal and the negative polarity RZ signal to generate a ternary signal. ) Is provided on the transmitting side to transmit the ternary signal, and separate the positive RZ signal and the negative RZ signal from the received ternary signal, respectively. Means (7, 8) for demodulating the positive polarity RZ signal to generate first analog information Demodulation means (9), second positive / negative polarity inversion means (10) for inverting the negative polarity RZ signal to generate a second positive polarity RZ signal, and the second positive polarity RZ signal. And a second demodulation means (11) for demodulating the second analog information to generate second analog information on the receiving side, and reproduce the two original analog information respectively.