JPS6096036A - Auxiliary signal transmission system - Google Patents

Abstract

PURPOSE:To obtain a microwave single side band auxiliary signal transmission system not requiring an exclusive band by transmitting an amplitude equalization pilot signal inserted to a transmission signal while being applied with angular modulation with an auxiliary signal comprising an ordering signal, a supervising control signal and a line switching control signal or the like. CONSTITUTION:Main signals from a carrier terminal station (not shown) fed to terminals 50, 51, e.g., SIG-1 and SIG-2 are modulated by an output wave of a pilot signal oscillator 3 and after they are increased to an intermediate frequency band, the result is fed to a hybrid circuit 12. On the other hand, an amplitude equalization pilot signal from pilot signal oscillators 6, 8, 10 is frequency- modulated shallowly at frequency modulators 7, 9, 11 by using an ordering signal inputted to terminals 52, 53, 54, a supervising control signal and a switching control signal. Then the signal is synthesized with the main signals SIG-1 and SIG-2. A microwave single side band signal inputted to a terminal 55 of the receiver is amplified/frequency-converted at a reception section 20 and then fed to an amplitude equalizer 21.

Description

[Detailed Description of the Invention] +a+ Technique of the Invention Field of the Invention The present invention relates to an auxiliary signal transmission system, and in particular, in a large-capacity single sideband communication system, it is possible to transmit an auxiliary signal without widening the transmission band. This relates to an auxiliary signal transmission method.

(bl) Prior Art and Problems FIG. 1 shows an example of the arrangement of transmission signals in a single sideband communication system using a microwave band.

In the figure, Po is the pilot signal for carrier synchronization,
P1 to P3 are pilot signals for amplitude control, and as shown in the figure, these are used to equalize the amplitude of a band of about 45 to 85 Ml1z, for example. 5IG-1 and 5IG-2 are multiplex telephone signals (main signals), for example, telephone signals of 2700 lines each.

Next, Figure 2 shows a meeting signal, which is a component of the auxiliary signal.
An example of arrangement in which supervisory control signals and line switching control signals are multiplexed is shown.

In the same figure, for example, Kano sends a meeting signal of 0.3 to 3.3 KIIz, Sv&C sends a 1200 baud supervisory control signal,
The total shows line switching control signals allocated to 6 waves in the 0.8 to 4KHz band, and when these are frequency multiplexed, the frequency is 0.3 to 1.
A band of about 2 KHz is required.

Then, as in the case of the frequency modulation method, such auxiliary signals are used in the lower band of the main signal shown in FIG. 1, such as the pilot signal Po for carrier synchronization and the pilot signal P for amplitude equalization.
2, a double-sideband or single-sideband modulation method must be used;
A narrowband bandpass filter is required in the intermediate frequency band of t z or 140 MIIz, and it is very difficult to realize this bandpass filter.

Therefore, there was a problem in that this auxiliary signal had to be transmitted using a dedicated band.

(C1 Purpose of the Invention The present invention has been made in view of the problems of the prior art described above, and an object of the present invention is to provide a microwave single sideband auxiliary signal transmission system that does not require a dedicated band.

(dl Structure of the Invention The object of the invention is to configure a pilot signal for amplitude equalization inserted into a transmission signal into a meeting signal, a supervisory control signal, a line switching control signal, etc. in a large-capacity single sideband communication system. This is achieved by providing an auxiliary signal transmission method characterized in that the auxiliary signal is angle-modulated and transmitted.

Embodiment of the Invention The present invention attempts to shallowly angle-modulate the amplitude equalization pilot signal using the auxiliary signal of, for example, 0.3 to 12 KHz as shown in FIG. It is something to do.

In this case, if the amplitude equalization pilot signal is frequency-modulated at the highest frequency of 12 KHz, the required transmission band will be approximately 2 x 12 KHz = 24 KHz, but this will affect the main signals 5IG-1 and 5IG-2 and the pilot signal. Taking into consideration the ease of implementing a signal extraction filter, this auxiliary signal is divided into three parts, each of which shallowly modulates a different pilot signal, resulting in 2 x 4KH in the transmission band.
z = 8 KHz, and the conventional pilot signal detection filter can be used as is.

FIG. 3 is a diagram showing the spectrum distribution when three pilot signals are each frequency-modulated with an auxiliary signal divided into three, and only the first sideband appears on both sides of the amplitude equalization pilot signal.

Generally, frequency modulated waves are Not much has changed.

In addition, the carrier wave is I. On SinΩ, the modulated wave is ΔΩCosωL
where ΔΩ/ω represents the modulation index mf.

As explained above, by shallowly frequency modulating or phase modulating each pilot signal with the auxiliary signal divided into three, it becomes possible to transmit without affecting the main signal.

4 and 5 show schematic block diagrams of a transmitter and a receiver for implementing the present invention.

In the figure, 1 and 4 are mixers, 2 and 5 are bandpass filters,
3, 6, 8. and 10 is a pilot signal oscillator; 7.
9 and 11 are frequency modulators, 12 is a hybrid circuit, 13 is a transmitter, 20 is a receiver, 21 is an amplitude equalizer, 22, 23 . and 24 are pilot signal extraction filters for amplitude equalization, 25.26 and 27 are biloft signal detectors for amplitude equalization, 28 is a processor, and 29.30
and 31 are demodulators, and 50 to 59 are terminals, respectively.

These parts are connected as follows.

In FIG. 4, a terminal 50 is connected to a mixer 1 and a bandpass filter 2, a terminal 51 is connected to a mixer 4 and a bandpass filter 5, and a pilot signal oscillator 6, 8, . and 10 are connected to a hybrid 12 which is connected to a transmitter 13 via frequency modulators 7.9 and 11, respectively.

Further, the terminals [1, 1, (21 and (3)) of the pilot signal oscillator 3 are connected to the mixer 1, the hybrid circuit 12, and the mixer 4, respectively.
゜53 and 54 are another 6 of the frequency modulators 7.9 and 11
111 children respectively.

In FIG. 5, the terminal 55 is connected to the receiving section 20. The terminal 56 connects to the processor 28 via the amplitude equalizer 21 and the processor 28 via the amplitude equalization pilot signal extraction filters 22, 23 and 24, and the amplitude equalization pilot signal detectors 25, 26 and 27, respectively. connected to. Also, terminals 57, 58 and 59
are connected to the terminals (1) of amplitude equalization pilot signal extraction filters 24, 23 and 22 via demodulators 29, 30 and 31, and the output of the processor 28 is connected to the amplitude equalizer 21, respectively.

Note that the dotted line portions in FIGS. 4 and 5 are portions added for implementing the present invention.

The operation of each of these programs is as follows.

First, main signals from carrier terminal stations (not shown) applied to terminals 50 and 51 in FIG. 4, such as 5IG-1 and 5I
G-2 is modulated by the output wave of the pilot signal oscillator 3, raised to an intermediate frequency band, and then applied to the hybrid circuit 12.

On the other hand, the amplitude equalization pilot signals from the pilot signal oscillators 6.8 and 10 are transmitted to the frequency modulators 7, 9 and 11 by the meeting signal, supervisory control signal and switching control signal inputted to the terminals 52, 53 and 54, respectively. shallow (frequency modulated and then applied to the hybrid circuit 12).

Here, it is combined with the main signals 5IG-1 and 5IG-2 and a signal arranged as shown in FIG. .

A microwave single sideband signal input to a terminal 55 of the receiver shown in FIG.

The amplitude equalizer 21 receives amplitude equalization pilot signals P1 to PB.
This part equalizes the amplitude within the band P1 to P- by comparing the amplitude between them with a reference value.The output of the amplitude equalizer 21 is branched to equalize the amplitude when the no-load Q is about 1000. The levels of the amplitude equalization pilot signals P1 to 111 detected using the pilot signal extraction filters 22, 23, and 24 and the amplitude equalization pilot signal detectors 25, 26, and 27 approach predetermined values. Similarly, the amplitude equalizer 2 is operated by the processor 28.
The resonant frequency of the resonator included in 1.

is controlled to flatten the amplitude characteristics within the band 11 to P.

A part of the outputs of the amplitude equalization pilot signal extraction filters 22, 23 and 24 are sent to the demodulators 29, 30.
and 31, and the meeting signal, supervisory control signal and line switching control signal are taken out from terminals 57, 58 and 59.

Note that it is also possible to modulate and transmit a specific pilot using all of the multiplexed signals shown in FIG.

(fl As described in detail, according to the present invention, the meeting signal, supervisory control signal, and line switching control signal are transmitted by modulating the amplitude equalization pilot signal. These signals can be inserted and removed at low cost without expanding the exclusive band l].

[Brief explanation of the drawing]

Figure 1 shows an example of the arrangement of transmission signals in a single sideband communication system using a microwave band, Figure 2 shows an example of the arrangement of auxiliary signals, and Figure 3 shows an example of the arrangement of auxiliary signals.
The figure shows an example of distributing auxiliary signals to each pilot signal.
5 and 5 each show a transmitter and a receiver as an example for implementing the present invention. In the figure, 1 and 4 are mixers, 2 and 5 are bandpass filters,
3, 6.8 and 10 are pilot signal oscillators, 7, 9
and 11 is a frequency modulator, 20 is a receiving section, 21 is an amplitude equalizer, 22.23 and 24 are pilot signal extraction filters for amplitude equalization, and 29.30 and 31 are demodulators, respectively. show. Arithmetic 1 Decoy 4SLJ? 7tr 95° M wave number CMH etc.) Single 2
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Claims (1)

[Claims] In large-capacity single sideband communication systems, the amplitude equalization pilot signal inserted into the transmission signal is angularly modulated with auxiliary signals consisting of meeting signals, supervisory control signals, line switching control signals, etc., and then transmitted. An auxiliary signal transmission method characterized by: