JPS60240228A - Heterodyne repeating system - Google Patents

Abstract

PURPOSE:To reduce frequency deviations in case of multirepeating by interlocking and controlling a frequency of each local oscillator of reception and transmission to a specified relation, in a heterodyne repeating hot stand-by diversity receiving system. CONSTITUTION:Receiving inputs (b), (c) are mixed with an oscillation frequency of receiving station oscillators 22a, 22b, and its intermediate frequency output is synthesized or switched by switching devices 28a, 28b and inputted to transmitting parts 24a, 24b. Each transmitting part converts it to a high frequency signal by transmitting station oscillators 25a, 25b and sends it to a transmitting end (a) through a synthesizer 26. Said each station oscillating part is controlled by two frequency controllers 27a, 27b, and deviation frequency controllers 32a, 32b, respectively. That is to say, the transmitting station oscillators 25a, 25b are controlled so as to oscillate a frequency f1 by a control output of the controllers 27a, 27b. On the other hand, the receiving station oscillators 22a, 22b are controlled by a signal which has mixed an output of the deviation frequency controllers 32a, 32b for oscillating a frequency determined by a transmitting and receiving frequency, and a multiplied output of the controllers 27a, 27b, and oscillate a frequency f2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a heterodyne relay system in route protection or hot standby diversity reception in a heterodyne system, and in particular, to a system for reducing frequency shift in multiple relays. Low performance and system cost are associated with heterodyne relaying.

[Prior art]

Conventionally, in the heterodyne system, for example, a high frequency signal received by two receivers is converted to an intermediate frequency using a common high frequency local oscillator with a set of spares, and a synthesizer or a switch with a set of spares is used. After switching, a hot standby diversity reception method is adopted in which one of the set spare transmitters is switched to transmit.

An example of a conventional hot standby diversity reception system of this kind is shown in FIG. 1 and will be explained. In the figure, a indicates a transmitting end, b and c are receiving input terminals, and these receiving input terminals s and c are as follows. For example, the receiving ends of the main antenna and the diversity antenna in a space diversity receiver are shown.

And 1m+1b are receivers 21 and 2b that receive the high frequency signals received at the receiving ends and @, respectively.
is a high-frequency local oscillator, 3m and 3b are switches for switching the outputs of the high-frequency local oscillators 21 and 2b, respectively, and 4 is a receiver 1m that takes the output of these switchers 3m and 3b as input and distributes this input, respectively. 1b is a high frequency signal distributor, and 5m+5b are each receiver 1.
an intermediate frequency synthesizer or switch (hereinafter referred to as an intermediate frequency synthesizer) that synthesizes intermediate frequency signals from m and 1b;
3m and ib are transmitters that convert and amplify the signals from the intermediate frequency synthesizers 5m and 5b, respectively, into high frequency signals, and the transmitters 6a and 6b are local oscillators 2a and 2b, respectively.
It has a built-in l2b'. Reference numerals 7m and 7b are high-frequency switchers for selectively switching the high-frequency signals from the transmitters (ia and 6b), and 8 is a combiner for combining the outputs of the high-frequency switchers 7m and 7b and sending the result to the transmitting end a.

Point d of the receiver 1a is connected to point d of the intermediate frequency synthesizer 5b, and point 0 of the receiver 1b is connected to point 0 of the intermediate frequency synthesizer 5a.

In the receiving system configured in this way, the high frequency signals received at the receiving end (receiving input end) b and the receiving end (receiving input end) C are oscillated by high frequency local oscillators 2a and 2b, respectively, in the receiver la llb. It is mixed with the frequency and converted into an intermediate frequency band signal (IF). By the way, these high-frequency local oscillators 2m and 2b have two oscillators set in reserve, and their oscillation output is controlled by a switch (
Switch) 3a.

The signal is supplied to two receivers 1a and 1b through a signal splitter 4 through 3b. These two receivers 1m and 1b each receive an intermediate station waveband signal (IF
) is sent to an intermediate frequency synthesizer 5.

After being combined or selectively switched by the sbt level switch,
The signals are input to two transmitters 6m and 6b, respectively. Then, each of the transmitters 5a, (ib) mixes the IF multiplied signal with the oscillation frequency of the high frequency local oscillator 2a'12b' and converts and amplifies it into a high frequency signal, and the converted and amplified high frequency signal is sent to each high frequency switch 7m. , 7b, and their outputs are combined by a combiner 8 and sent to the transmitting end a.

In this case, the local oscillator 2a in the two transmitters 6m+6b
'12b' are each independent.

FIG. 2 is a block diagram of another example of this type of conventional receiving system.

In this Figure 2, the same numbers as in Figure 1 indicate corresponding parts, 9m and 9b are two high frequency local oscillators prepared as a set, and 10m and 10b select the output from this high frequency local oscillator 9a lab. The switching device 11 is a signal distributor that distributes and supplies the outputs of the switching devices 19a and 10b to the transmitters 6m and 6b, respectively.

In the block diagram shown in FIG. 2, the receiver configuration is the same as that in FIG. The high frequency local oscillators 9m and 9b are shared, so the high frequency local oscillators 9m and 9b are shared, so that The switch 7m + 7b is unnecessary, and the in-phase combination is performed by the combiner 8, which has the advantage of increasing the transmission output compared to the configuration shown in Fig. 1.Also, the route backup method and the heterodyne relay method
In the hot standby relay system, the two transmitters 6m+6b and the receivers 11 and 1b have the same configuration, except that the frequencies are different.

However, such a hot standby diversity reception system has the disadvantage that when multiple relays are performed, the frequency deviations of the receiving and transmitting local oscillators are added, degrading the transmission quality. The drawback is that increasing the stability increases the price.

[Object and structure of the invention]

In view of the above points, the present invention has been made in order to solve such problems and eliminate such drawbacks.The purpose of the present invention is to solve the problems described above and to eliminate such drawbacks, which occur when multiple relays of intermediate frequency band signals are carried out using a simple configuration. It is an object of the present invention to provide a heterodyne relay system which can eliminate the addition of frequency shifts and at the same time can be made at low cost.

In order to achieve such an object, the present invention sets the local oscillation frequency of the transmitting local oscillator of the transmitter to fl + the local oscillating frequency of the receiving local oscillator of the receiver to f2, and the frequency of each local oscillation number f1 and f2. When the difference is f, the transmitting local oscillator is controlled at the frequency fx1=fx/m (m is an integer) generated by the frequency controller, and '&=f@'' is generated by the shift frequency controller. (Integer n<m)
A frequency converter mixes the frequency f
The frequency is converted to jcIXn+f@ (or fzlXn-fl), and the receiving local oscillator is controlled using this frequency. - [Example] Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 3 is a block diagram showing an embodiment of the heterodyne relay system according to the present invention, and shows an example in which the present invention is applied to heterodyne relay hot standby diversity reception.

In FIG. 3, the same parts as in FIGS. 1 and 2 are designated by the same reference numerals, and their explanation will be omitted.

21m and 21b are receivers that receive high-frequency signals from the reception input terminals s and e of the main antenna and the diversity antenna, respectively;
1b is a high frequency local oscillator (receiving local oscillator) whose oscillation frequency is controlled by the output of the frequency control section 2
Built-in 2m and 22b. 23a.

23b is an intermediate frequency synthesizer for synthesizing or selectively switching intermediate frequency band signals (IF) converted by the high frequency local oscillators 22m and 22b in the receivers 21m and 21b, respectively; 24m and 24b are intermediate frequency synthesizers zaa and 24b, respectively; Each of these transmitters 24m and 24b includes a high-frequency local oscillator (transmission local oscillator) 2sa and 25b whose oscillation frequency is controlled by the output of a frequency control section. Reference numeral 26 denotes a high frequency synthesizer that combines the high frequency signals converted by the high frequency local oscillators 25m and 25b in the transmitters 24m and 24b, respectively, and sends the synthesized signal to the transmitting end a.

27m, 27b are frequency controllers, 29m, 28
b is a switch that selects and switches the output of the frequency controllers 27m + 27b, and these switchers 281 and 28
Through the output signal distributor 29 of the transmitter 24m, the transmitter local oscillator 25 of the transmitter 24m and the transmitter local oscillator 2 of the transmitter 24b
5b.

30m and 30b are multipliers that multiply the branch outputs of the switching devices 281 and 28b, respectively, and the outputs thereof are configured to be input to frequency converters a1m and 31b, respectively. 32m and 32b are shift frequency controllers,
The outputs thereof are configured to pass through switchers 33m and 33b and a signal divider 34, respectively, and are branched into two by the signal divider 34 and input to frequency converters 31a and 31b, respectively. The outputs of the frequency converters 31m and 31b are respectively F-wave converters as
Receive local oscillator 22m, 2 through a, 35b
2b, and each receiving local oscillator 22m, 22
It is configured to control the oscillation frequency of b.

Next, the operation of the embodiment shown in FIG. 3 will be explained. Note that, although the hot standby relay method will be explained below as an example, the same applies to the route backup method if one set of transmitting and receiving devices is considered.

First, the high frequency signals input to the reception input terminals and reception input terminals C are input to the receivers 21m and 21b, respectively, where they are mixed with the oscillation frequency of the reception local oscillators 22a + 22b and converted into intermediate frequency signals. The outputs are combined or switched by intermediate frequency synthesizers or intermediate frequency switchers 23m and 23b, respectively, which are prepared as a set, and the outputs thereof are sent to a transmitter 24a.

24b, respectively. And this transmitter 24
In m and 24b, the input intermediate frequency signals are mixed with the oscillation frequencies of transmitting local oscillators 25m and 25b and converted into high frequency signals, respectively, and these high frequency signals are combined by high frequency synthesizer 26 and sent to transmitting end a. Ru.

Next, the four local oscillators, the transmitting local oscillators 25a, 25b of the transmitters 24m, 24b and the receiving local oscillators 22&, 22b of the receivers 211, 21b, are each controlled by two frequency controllers 27&, 27b. However, this control operation will be explained.

First, the outputs of the two frequency controllers 27m and 27b (frequency fxs) are switched to the switchers 28m and 28, respectively.
After being selected by b, it passes through the signal divider 29 and controls the two transmitting local oscillators 25a + 25b, respectively.

In this case, it is assumed that the relationship between the oscillation frequency f1 of the transmitting local oscillators 25a and 25b and the output frequency fit of the frequency controllers 27s1 and 27b is expressed by the following equation (1).

rx, X m = f 1 ・・・・・・・・・・・・
In the formula (1) with (1), m is an integer.

On the other hand, a part of the signals that have passed through the switchers zaa and 28b are branched, and the branched outputs are sent to the respective multipliers (n
multiplier) aoa and 30b, and is multiplied by n and input to frequency converters 311 and 31b, respectively. Further, the outputs of the shift frequency controllers 32m and 32b (frequency fa) are passed through switchers 33m and 33b, respectively, and are branched into two by a signal divider 34, which outputs the two frequency converters 31.
a.

31b, respectively. Then, each output of the frequency converter 31m + 31b is transmitted to an F-wave converter 35a.
.

35b, fxIXn+1m (or fXtXn
-ra) is selected and its output is the receiving local oscillator 22m
.

22b, and operate as a frequency control section. Here, the above n is an integer n(m).

Now, the transmitting local oscillator 25m and the receiving local oscillator 25
Let each oscillation frequency of b be fl + f'2, and let the difference be fll, and further assuming the following equation (3), flN
f2===f, ・・・・・・・・・・・・・・・・・・
... (2) (fx summer Xn+r,)X! = 12
−−−−−−・・−−,,・(3)

Then, according to the above equations (1), (2>, and (3), f
.

fX1=-・・・・・・・・・・・・・・・・・・
・・・・・・(4)fa=f,−・・・・・・・・・
・・・・・・・・・・・・・・・(5) fXl and f
l may be determined as in the above equations (4) and (5).

Then, the difference f of the oscillation frequency fl+f2, or n/
If the value of m is decreased, the shift frequency controller 32a.

Although the stability of the output frequency f of the oscillator 32b may be low, since the difference f between the oscillation frequencies fl + f2 is usually fixed, it is sufficient to reduce n/In. However, n/r
When n is made small, it is limited by the band and stability of the F-wave generators 35m and 35b.

Although the present invention has been described above with respect to a heterodyne relay hot standby diversity reception method, the same method as the hot standby diversity reception method described above can be applied to a heterodyne relay consisting of one or more receivers and one or more transmitters. It goes without saying that it is possible to realize a heterodyne relay transmission/reception system that performs frequency control using the system described above.

[Effects of the Invention] As is clear from the above explanation, according to the present invention, in the heterodyne system and hot standby diversity reception, it is possible to eliminate the addition of frequency shifts, which is a problem when repeating heterodyne intermediate frequencies multiple times. In addition, instead of the four highly stable high-frequency local oscillators used previously, four simple high-frequency oscillators and two frequency controllers that control their frequencies are commonly used for the four high-frequency oscillators. In particular, the cost can be reduced, so the practical effect is extremely large.

[Brief explanation of the drawing]

Figure 1 shows an example of a conventional heterodyne relay system.
2 is a block diagram showing another example of the conventional heterodyne relay system, and FIG. 3 is a block diagram showing an embodiment of the hetero gain relay system according to the present invention. 2ja, 21b・””receiver, 22&, 22b-
---Receiving local oscillator, 23m, 23b...Intermediate frequency synthesizer, 24&, 24b ---Transmitter,
zsa, 25b...ψ・Transmission local oscillator, 26...
...High frequency synthesizer, 27&, 27b...Frequency controller, 29...ψ signal distributor, 30m, 30b
Multiplier, 31m, 31b---frequency converter, aza, 32b---deviation frequency controller,
34...Signal distributor. Patent Applicant NEC Corporation Agent Masaki Yamakawa (Kamaka 2)

Claims (1)

[Claims] The high frequency signal from the receiving input terminal is mixed with the oscillation frequency of the receiving local oscillator and converted into an intermediate frequency signal.The output intermediate frequency signals of two or more receivers are combined, and this combined signal is combined with the oscillation frequency of the transmitting local oscillator. In heterodyne relay hot standby diversity reception in which the output signals of two or more transmitters are combined or switched and outputted to the transmitting end by mixing and converting them back into high-frequency signals, the local oscillation frequency f1 of the transmitting local oscillator + the receiving local section When the local oscillation frequency of the oscillator is f2, and the frequency difference between the local oscillation frequencies f1 and f2 is f8, fx generated by the frequency controller
f, which controls the transmitting local oscillator at a frequency of t=ft/m (m is an integer) and is generated by a shift frequency controller;
A frequency converter mixes the frequency =f, 5 (an integer where n<m) and the frequency fzIXn, which is fxl from the frequency controller multiplied by n, to generate fxIXn±fa ('t or fzIXn-1@). A hetero gain relay system characterized in that the receiving local oscillator is controlled using this frequency.