JPH04236522A - Branching insertion method and branching insertion device - Google Patents

Abstract

PURPOSE:To allow the method to cope with diversified services by adopting the constitution such that no MODEM is provided to an intermediate relay station and non-regeneration relay is implemented therein and branching and inserting a signal onto a frequency axis of an intermediate frequency band or a radio frequency band. CONSTITUTION:Since an intermediate relay station 10 is subject to non- regenerative relay, a signal branching insertion circuit 9 has no MODEM and a signal is switched on a frequency axis. Thus, an input signal of the circuit 9 is allocated in an optional idle frequency band and sent to a succeeding relay station via a transmitter 2, a transmission reception common device 6 and an antenna 1-3 or 1-4. Moreover, a reception signal from other relay station than the relay station 101 is inputted to the circuit 9 via the antennas 1-3,1-4, the device 6 and the receiver 3. The relay station 105 communicates with one relay station 105'. Thus, a signal allocated to an optional frequency is relayed from the relay station 101 to relay stations 101' and 101'', or from the relay station 101'' to relay stations 101' and 101.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to communication systems that require relaying, and more particularly to techniques for branching or adding signals at relay stations.

0002

[Prior Art] FIG. 9 shows an example of drop/add in wireless communication as a typical prior art.
-9 represents an antenna. Taking the downlink as an example in the figure, the signal received at the An station 501 is received by the antenna 51-6, and then sent to the transmitting/receiving device 5.
6 and input to the receiving device (RX) 53. The output signal of the receiving device 53 is input to a demodulating device (DEM) 55 and the transmitted signal is demodulated. The demodulated signal is sent to the modulator (
MOD) 54, and further transmitted to a transmitting device (TX) 52.
, and is transmitted from the antenna 51-5 to the next relay station via the transmitting/receiving device 56 (on the uplink, it is relayed through the reverse route). An station 501 is formed as an intermediate relay station with such a configuration.

[0003]The drop/add of signals is performed at the terminal relay station A.
This is done at the l station 502 or the AN station 503. branch,
The inserted signal is provided at the output of the demodulator 55 or at the input stage of the modulator 54 via the interface circuit 57.

0004

[Problems to be Solved by the Invention] As described above, in the conventional technology, signal drop/add is performed via the modulation/demodulation devices 54 and 55. Therefore, when changing the transmission capacity, etc., it is necessary to add/drop signals at all intermediate relay stations or terminal relay stations. Modulation and demodulation devices 54 and 55 must be changed. Furthermore, when data is added/dropped, an interface circuit 7 is required for all modulated/demodulated baseband bands, which tends to increase the circuit scale.

[0005] Furthermore, it is not possible to flexibly respond to changes in the number of modulation/demodulation devices, the number of multi-values of the modulation/demodulation method, and the clock speed due to long-term traffic fluctuations (demand fluctuations), and short-term traffic In order to cope with fluctuations (for example, fluctuations between daytime and nighttime), it is necessary to install a number of modems corresponding to the maximum traffic at each relay station, resulting in a problem that the usage efficiency of the modems is low. Furthermore, there is also the inconvenience that connection to different transmission media must be made via a modulation/demodulation device.

[0006] The present invention provides a means for performing signal drop/add with a simple configuration that can quickly respond to diversified services, and is capable of responding to traffic fluctuations and medium changes. The purpose of this research is to provide a communication system that realizes a circuit configuration that can respond flexibly and efficiently to various situations.

[0007]

According to the invention, the above objects are achieved by the means set out in the claims.

That is, the invention according to claim 1 provides a communication method in which a frequency multiplexed signal is transferred, and a part of the frequency multiplexed signal is dropped and inserted at N relay stations having drop/add means. In addition to the signal, N control signals are transmitted by frequency multiplexing, information specifying the connection conditions of the corresponding add/drop circuit is transferred by the control signal, and the control signal is extracted at the relay station where the add/drop is to be performed. This is a drop/add method in which the connection of the drop/add means is set and drop/add is performed in an intermediate frequency band or a radio frequency band.

Further, the invention of claim 2 relates to the configuration of the drop/add means, and as shown in FIG. a removal filter that receives a signal and removes the control signal; a frequency shift circuit (12-1) that receives the output signal of the removal filter and changes the signal to an arbitrary frequency band;
(12-2), and bandpass filters (20-2) and (20-4) that pass only the control signal from one input side.
), and adders (13-3) and (13-6) that combine the output of the bandpass filter and the output of the frequency shift circuit.
), an adder (13-2) that combines the outputs of the adders (13-3) and (13-6) with a signal from the other input side,
(13-5) and outputs the output of the adder from one output side (106-1), (106-2);
Removal filters (19-1) and (19-3) that input a control signal and a signal from one input side and remove the control signal, and a signal that inputs the output signal of the removal filter and demultiplexes a desired signal. Pass circuits (16-1), (16-2), band pass filters (20-1), (20-3) that pass only the control signal from one input side, and an output signal of the band pass filter. adders (13-1) and (13-4) that add the outputs of the signal passing circuit and the signal passing circuit; and a removal circuit (15-1) that removes the desired signal branched from one input side.
(15-2), and a duplexer (107-1), (107-2) from which the output of the removal circuit is output from the other output side;
The control signal of the input signal of the branch/add circuit is detected, and each branching filter (
107-1), (107-2) and combiner (106-1)
, (106-2) and a circuit 108 for controlling voltage-controlled local oscillators.

0010

[Operation] The present invention has a configuration in which non-regenerative relay is performed without a modulation/demodulation device at an intermediate relay station, and the main feature is that the signal is added/dropped on the frequency axis of the intermediate frequency band or radio frequency band. .

[0011] In contrast to the conventional technology, which performs signal drop/add only in the baseband, the present invention
The difference is that the signal is added/dropped in the intermediate frequency band or radio frequency band as described above. Hereinafter, the effects of the present invention will be explained in detail based on examples.

0012

[Embodiment] FIG. 1 is a diagram illustrating a first embodiment of the present invention.
-6, 1-7, 1-8, 1-9, 1-10 are antennas,
2 is a transmitting device, 3 is a receiving device, 6 is a transmitting/receiving shared device, 9,
9' is a signal add/drop device, 21 is a local frequency control signal generator, 101, 101', 101'' are intermediate relay stations,
105 and 105' represent relay stations equipped with modem equipment.

In the figure, a relay station 105 transmits a signal from a modulation/demodulation device 10 to a local frequency control signal generator 21.
, the transmitting device 2, the transmitting/receiving device 6, and the antenna 1-1 to the intermediate relay station 101. Also relay station 10
5 is antenna 1 from antenna 1-2 of intermediate relay station 101
-1, a signal is input to the modulation/demodulation device 10 via the transmitting/receiving device 6 and the receiving device 3. At the intermediate relay station 101, the output signal from the signal add/drop device 9 is transmitted to the relay station 10 via the transmitting device 2, the transmitting/receiving device 6, and the antenna 1-2.
Sent to 5. On the other hand, the received signal from the relay station 101 is inputted to the signal drop/add circuit 9 via the antenna 1-3 or 1-4, the transmitting/receiving device 6, and the receiving device 3.

Here, since the intermediate relay station 101 is a non-regenerative repeater, the signal drop/add circuit 9 does not include a modulation/demodulation device and switches on the frequency axis, and the input signal of the signal drop/add circuit 9 is input to any available signal. assigned to the frequency band of
The signal is transmitted to the next relay station via the transmitting device 2, the transmitting/receiving device 6, and the antenna 1-3 or 1-4.

[0015] Also, the reception signals from other intermediate relay stations at the intermediate relay station 101 are transmitted to the antenna 1-3 or 1-3.
4, the signal is inputted to the signal add/drop circuit 9 via the transmitting shared device 6 and the receiving device 3. Relay station 105 is one relay station 10
5', the signal assigned to an arbitrary frequency is relayed from the intermediate relay station 101 to the intermediate relay station 101'' via the intermediate relay station 101', or from the intermediate relay station 101'' to the intermediate relay station 101''. Signals are relayed to the intermediate relay station 101 via the intermediate relay station 101'.

The signal received at the intermediate relay station 101' is received by the antenna 1-5 and input to the receiving device 3 via the transmitting/receiving device 6. The output signal of the receiving device 3 is outputted from the antenna 1-6 via the transmitting device 2 and the transmitting/receiving device 6, and is transmitted to the next relay station. The signal received at the intermediate relay station 101'' is inputted to the signal drop/drop/add circuit 9' via the transmitting/receiving device 6 and the receiving device 3.

Here, the signal of the relay station 105 assigned to an arbitrary frequency is branched and inputted to the antenna 1-9 of the relay station 105' via the transmitting device 2, the transmitting/receiving device 6, and the antenna 1-8. Antenna 1- of relay station 105'
The signal input to the transmitter/receiver 9 is input to the modulation/demodulation device 10 via the transmitting/receiving device 6 and the receiving device 3. On the other hand, relay station 105
The output signal of ' is sent to an intermediate relay station 101'' via a modulation/demodulation device 10, a local frequency control signal generator 21, a transmitting device 2, a transmitting/receiving device, and an antenna 1-9.

[0018] At the intermediate relay station 101'', the relay station 105'
The signal received from the antenna 1-8, the transmitting/receiving device 6,
The signal is inputted via the receiving device 3 to the signal add/drop circuit 9'. Similar to the intermediate relay station 101, the signal input to the signal add/drop circuit 9' is assigned to an arbitrary frequency and sent to the intermediate relay station 1 via the transmitting device 2, the transmitting/receiving device 6, and the antennas 1-7.
01', the signal is relayed.

FIG. 2 shows the configuration of the signal add/drop circuits 9, 9'. The operation will be explained below using the downlink as an example. On the downlink, A. B. A signal C and a control signal L for controlling the local frequencies of the combiner 106-1 and the demultiplexer 107-1 are sent in a frequency arrangement as shown in the figure as an example.

The signal add/drop circuits 9, 9' are branching filters 107
Branched before −1 input, local frequency control circuit 108
The circuit detects a local frequency control signal L. In the local frequency control signal L, control information corresponding to each signal drop/drop/add circuit 9, 9' is arranged on the frequency axis as shown in FIG. Note that the frequency of the local frequency control signal L (L1, L2,...Ln) is different from that of the intermediate relay station 10.
1,101',101'' or relay station 105,105
′ is the same. The local frequency control circuit 108 detects this control signal and sends it out as a control signal.

FIG. 4 shows the configuration of the local frequency control circuit 108. In the same figure, input signals are synthesized by an adder 13-7, frequency-converted by a local oscillator 22 and a mixer 17-1, and then passed through a band-pass filter 23 to extract the signal drop/add circuit control signal of the local station. By inputting this signal to the wave detector 24, a local frequency control signal is sent out.

At this time, the control signal L1 (or L2) is
The control signal is transmitted from the local frequency control signal generator 21 of the relay station 105 or 105', but since the control signal to the same signal add/drop circuit 9 (or 9') has the same frequency, the control signal is transmitted by communication. Transmission is performed only from one of the final relay stations performing the process, that is, relay station 105 or 105' in this embodiment.

Control signal L1 of the signal add/drop circuit in this example
Assuming that the signal C is branched and a signal C' is inserted into the downlink, the corresponding control signal is sent from the local frequency control circuit 108 to the synthesizer 10.
6-1 and a demultiplexer 107-1.

The signal input to the demultiplexer 107-1 is divided by the divider 14-1, and one signal is further divided into a signal removal filter 19-1 and a band-pass filter 2.
Enter 0-1. The signal removal filter 19-1 has the function of removing only the control signal L, and the bandpass filter 20-1 has the function of passing only the control signal L. The output signal of the signal removal filter 19-1 includes signals A, B,
Only the signal C is output, and only the signal C that is distributed by passing through the signal passing circuit 16-1 is output.

The output of the band pass filter 20-1 and the output signal of the signal passing circuit 16-1 are combined by an adder 13-1,
Port 3 outputs distribution signal C and control signal L having the same frequency band as the signal add/drop circuit input. Distributor 14
The other signal distributed by the signal removal circuit 15-
1 to remove only the distributed signal C, and then input it to the combiner 106-1.

The signal input to combiner 106-1 is input to adder 13-2. C′ input from port 2
The signal and control signal L are input to a signal removal filter 19-2 and a bandpass filter 20-2. The signal removal filter 19-2 has the function of removing only the control signal L, and the bandpass filter 20-2 has the function of passing only the control signal L. Only the C' signal is output as the output signal of the signal removal filter 19-2, and the frequency shift circuit 12-1
becomes the frequency band of the distributed C signal.

Only the control signal L is output to the output of the band pass filter 20-2, and the output of the band pass filter 20-2 and the output signal of the frequency shift circuit 12-1 are combined into the adder 1.
By combining the input signals at 3-3 and further combining the input signals at adder 13-2, the A, B, and C' signals from the output of the signal add/drop circuit 9 (or 9') and the same frequency as the input signal of the signal add/drop circuit are combined. A control signal L having a band is output. A specific circuit configuration of the frequency shift circuit, signal removal circuit, and signal passing circuit is shown in FIG.

The frequency shift circuit is configured as shown in FIG. 2A, and controls the voltage controlled local oscillator 18-1 by the control signal from the local frequency control circuit 108. By inputting the output signal of No. 1 to the mixer 17-2, the input signal (in this case, the C' signal) is frequency-shifted to an arbitrary frequency and output.

The signal removal circuit is configured as shown in FIG. 2(b), and controls the voltage-controlled local oscillator 18-2 with a control signal from the local frequency control circuit 108 and inputs it to the mixer 17-3. The center frequency of the signal to be removed is matched with the center frequency of the signal removal filter 19, and the signal (here, the C' signal) is removed. The output signal of the signal removal filter 19 is input to the mixer 17-4 and returned to the frequency band at the time of input to the signal removal circuit where it is multiplied by the output signal of the voltage controlled local oscillator 18-2.

The signal passing circuit is configured as shown in FIG.
By inputting the output signal of the voltage-controlled local oscillator 18-3 to the mixer 17-5, the center frequency of the signal to be branched matches the center frequency of the bandpass filter, thereby performing signal demultiplexing.

The operation of the signal add/drop circuit for the downlink has been described above, but the same operation is performed for the uplink as well. In this example, the multiplexer 106-1 and the demultiplexer 107-1
considers only the multiplexing and demultiplexing of one wave, but n (n=2,
3...) When performing wave multiplexing and demultiplexing, n multiplexers 10 are used.
6-1 and a duplexer 107-1 may be provided. At this time, the input signal and output signal of the local frequency control circuit 108 also increase.

FIG. 6 is a diagram illustrating a second embodiment of the present invention, in which the same numbers as in FIG. 1 are used for the same components as in FIG. The same applies to the figures below). This embodiment differs from the first embodiment in that the relay station 105 is composed of a TDMA base station 103, and the relay station 105' is composed of TDMA slave stations 104-1, 104-2, and 104-3. . Furthermore, TDM
A is communication in which the time for each station to transmit is divided on the time axis.

In the figure, a signal from a TDMA device 8 is transmitted from a TDMA base station 103 to a local frequency control signal generator 21, a transmitting device 2, a transmitting/receiving device 6, and an antenna 1-.
1 to the intermediate relay station 101. Also TDM
A base station 103 connects antenna 1-1 from intermediate relay station 101.
, the TDMA device 8 via the transmitting/receiving device 6 and the receiving device 3.
A signal is input to

At the intermediate relay station 101, the output signal from the signal add/drop circuit 9 is transmitted to the TDMA base station 103 via the transmitting device 2, the transmitting/receiving device 6, and the antenna 1-2. Further, a received signal from the TDMA base station 103 is inputted to the signal add/drop circuit 9 via the antenna 1-2, the transmitting/receiving device 6, and the receiving device 3.

Here, since the intermediate relay station 101 is a non-regenerative repeater, the signal drop/add circuit 9 does not include a modulation/demodulation device and switches on the frequency axis, and the input signal of the signal drop/add circuit 9 is input to any vacant assigned to a frequency band. The TDMA base station 103 has TDMA slave stations 104-1, 10
4-2 and 104-3, signals assigned to any frequency are relayed from the intermediate relay station 101 to the intermediate relay station 101'' or from the intermediate relay station 101'' to the intermediate relay station 101. will be relayed.

The signal received at the intermediate relay station 101'' is sent via the transmitting/receiving device 6 and the receiving device 3 to the signal add/drop circuit 9'.
is input. Here, the signal of the TDMA base station 103 assigned to an arbitrary frequency is branched and sent to the antenna 1 of the TDMA slave stations 104-1, 104-2, 104-3 via the transmitting device 2, the transmitting/receiving device 6, and the antenna 1-8. -9
, 1-11, 1-12. TDMA slave station 10
4-1, 104-2, 104-3 antenna 1-9, 1
-11, 1-12, the signals input to the transmitting/receiving common device 6
, are input to the TDMA device 8 via the receiving device 3.

On the other hand, TDMA slave stations 104-1, 104-
The output signal of 2,104-3 is sent to the intermediate relay station 101'' via the TDMA device 8, the local frequency control signal generator 21, the transmitting device 2, the transmitting/receiving device, and the antennas 1-9, 1-11, and 1-12. At the intermediate relay station 101'', the signals received from the TDMA slave stations 104-1, 104-2, and 104-3 are sent to the signal add/drop circuit 9' via the antenna 1-8, the transmitting/receiving device 6, and the receiving device 3. is input.

The signal input to the signal add/drop circuit 9' is sent to the intermediate relay station 101' via the transmitting device 2 assigned to an arbitrary frequency, the transmitting/receiving device 6, and the antennas 1-7, similar to the intermediate relay station 101. A relay will be held.

FIG. 7 is a diagram illustrating a third embodiment of the present invention. In the third embodiment, TDMA slave stations 104-1, 1
This embodiment differs from the second embodiment in that signals 04-2, 104-4, and 104-5 are composed of signals branched from two different intermediate relay stations 101' and 101''.

FIG. 8 is a diagram illustrating a fourth embodiment of the present invention, and the first point is that the relay between intermediate relay stations 101, 101', and 10'' is not done wirelessly but by wire (line 11). This is different from the embodiment.

In the embodiments described above, when constructing the communication mode shown in the second embodiment or the communication mode shown in the third embodiment from the communication mode shown in the first embodiment due to communication traffic fluctuations, etc., the terminal relay station 105 , 105' to the TDMA base station 103 and TDMA slave stations 104-1 to 104-5.

[0042]

As explained above, in the system of the present invention, non-regenerative relaying without a modulation/demodulation device is performed at the intermediate relay station, and signal drop/drop is performed in the intermediate frequency or radio frequency band. There are advantages in that the number of modulation and demodulation devices can be increased freely in response to long-term traffic fluctuations, and that the number of modulation and demodulation values, clock speed, etc. can be arbitrarily set. In addition, since modems are centrally placed in TDMA base stations, it is possible to realize a system that can respond to short-term traffic fluctuations with fewer modems than before due to the large grouping effect, and furthermore, it is possible to realize a system that can respond to short-term traffic fluctuations with fewer modems than before. can also be easily achieved. As described above, the present invention is superior in terms of the simplicity of the equipment configuration, the flexibility of the line configuration against traffic fluctuations, and the economical efficiency of implementing the system, compared to conventional baseband signal drop/add. .

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating a first embodiment of the present invention.

FIG. 2 is a diagram showing the configuration of a signal add/drop multiplexer.

FIG. 3 is a diagram illustrating a local frequency control signal.

FIG. 4 is a diagram showing the configuration of a local frequency control circuit.

FIG. 5 is a diagram showing the configurations of a frequency shift circuit, a signal removal circuit, and a signal passing circuit.

FIG. 6 is a diagram illustrating an embodiment of the body 2 of the present invention.

FIG. 7 is a diagram illustrating a third embodiment of the present invention.

FIG. 8 is a diagram illustrating a fourth embodiment of the present invention.

FIG. 9 is a diagram illustrating add/drop in conventional wireless communication.

[Explanation of symbols]

1-1 to 1-5 Antenna 2 Transmitting device 3 Receiving device 4 Modulating device 5 Demodulating device 6 Transmitting/receiving device 7 Interface circuit 8 TDMA device 9, 9', 9'' Signal add/drop circuit 10 Modulation/demodulation device 11 Line 12-1, 12-2 Frequency shift circuit 13-1 to 1
3-7 Adder 14-1, 14-2 Distributor 15-1, 15-2 Signal removal circuit 16-1, 16-2 Signal passing circuit 17-1 to 17-5 Mixer 18-1 to 18-3 Voltage Controlled local oscillator 19
, 19-1 to 19-4 signal removal filters 20, 20
-1 to 20-4 Bandpass filter 21 Local frequency control signal generator 22 Local oscillator 23 Bandpass filter 24 Detector 101, 101', 101'' Intermediate relay station 102
Terminal relay station 103 TDMA base stations 104-1 to 104-5 TDMA slave stations 105', 1
05″ Relay station 106-1, 106-2 Combiner 107-1, 107-2 Brancher 108 Local frequency control circuit

Claims (2)

[Claims] Claim 1. A communication method in which a frequency multiplexed signal is transmitted, and a part of the frequency multiplexed signal is dropped and added at N relay stations having drop/add means. A control signal is transmitted by frequency multiplexing, information specifying the connection conditions of the corresponding drop/add means is transferred by the control signal, and the control signal is extracted at the relay station where the drop/add means is to be added, and the connection of the drop/add means is performed. A drop/add method characterized in that the drop/add is performed in an intermediate frequency band or a radio frequency band by setting . 2. The branch/insertion means according to claim 1,
Removal filters (19-2) and (19-4) that input a control signal and a signal from one input side and remove the control signal, and input the output signal of the removal filter to convert the signal into an arbitrary frequency band. Frequency shift circuit (12-1), (1
2-2), bandpass filters (20-2) and (20-4) that pass only the control signal from one input side, and the output of the bandpass filter and the output of the frequency shift circuit are synthesized. adders (13-3), (13-6); an adder (13-2) that combines the outputs of the adders (13-3), (13-6) with a signal from the other input side; (1
3-5), a combiner (106-1), (106-2) which outputs the output of the adder from one output side, and inputs a control signal and a signal from one input side, removal filters (19-1) and (19-3) for removing the control signal;
Signal passing circuits (16-1) and (16-2) which input the removal filter output signal and separate the desired signal; and a bandpass filter (20-1) which passes only the control signal from one input side. ), (20-3), adders (13-1), (13-4) for adding the output signal of the bandpass filter and the output of the signal passing circuit, and a signal demultiplexed from one input side. Removal circuit (15-1) for removing the signal of (
15-2), a branching filter (107-1), (107-2) from which the output of the removal circuit is output from the other output side, and a branching/adding circuit that detects the control signal of the input signal and Wave device (1
07-1), (107-2) and combiner (106-1),
(106-2) A branch/add device comprising a circuit 108 for controlling a voltage controlled local oscillator.