JPH07298348A - Mobile communication system - Google Patents

Abstract

PURPOSE:To obtain the mobile communication system which is inexpensive in channel use charge and can send radio signals from respective transmission stations synchronously even when there is differences in the quantity of signal delay from an encoding device to the transmission stations. CONSTITUTION:The encoding device 30 is supplied with a calling signal from a subscriber 10 through an exchange 20, encodes it into a low speed encoded signal and a high speed encoded signal respectively, and multiplexes and outputs them. Transmission stations 401 and 402 delay signals, obtained by modulating and amplifying inputted multiplexed signals, by a specific time in synchronism with the timing of the received signals received by GPS receivers 411 and 412, and send them by radio. Transmission stations 501 and 502 receive and convert the high speed encoded signals in radio signals into low speed encoded signals, and send the low-speed encoded signals by radio in synchronism with the timing of the signals received by GPS receivers 511 and 512. A mobile receiver 60 receives the low-speed encoded signals from the transmission stations 401 and 402, and 501 and 502.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile communication system, and more particularly to a mobile communication system for wirelessly calling a mobile receiver.

[0002]

2. Description of the Related Art FIG. 4 is a block diagram showing an example of a conventional mobile communication system. As shown in the figure, this conventional system wirelessly calls the above-mentioned call signal input from the switch 20 through a communication line 21 and a switch 20 that switches and outputs the call signals called by a large number of subscribers 10. It is composed of an encoding device 70 for encoding signals and transmitting stations 80 ₁ to 80 _{4 for} wirelessly transmitting the radio call signals supplied from the encoding device 70 via the communication lines 91 to 94, respectively. In this configuration, the target mobile receiver 60 receives the call signal of.

Here, the above-mentioned encoding device 70 is used in the exchange 2.
A coding unit 71 that codes a calling signal input via 0, a distribution unit 72 that divides the output coded signal of the coding unit 71 into four, and a coded output signal of the distribution unit 72 is transmitted to each transmitting station. A variable delay unit 7 that delays by a set delay amount to make the delay amounts of 80 ₁ to 80 _{4 the} same.
3 to 76. In addition, each of the transmission stations 80 ₁ to 80 ₄ performs communication processing with respect to the call signal input via the communication lines 91 to 94 and outputs the processed communication signals 81 _{1 to} 81 ₄ and 81 _1. A transmitter 82 ₁ that modulates and amplifies the signals from ˜ 81 ₄ and transmits them as radio signals.
And a to 82 _4. In addition, the transmitting station 80 _1-
The number of 80 ₄ is ₄ here for the sake of simplicity, but 2
× n units are provided.

Next, the operation of this conventional system will be described. The calling signal originated by the subscriber 10 is connected to the encoding device 70 selected by the exchange 20 via the communication line 21. The encoding device 70 uses the encoding unit 71 to transmit the call signal from the exchange 20 to, for example, POCSA.
G (Post Office Code Standard)
rvision Advisory Group)
The signal is encoded, divided into four by the distribution unit 72, supplied to the variable delay units 73 to 76, and delayed. As will be described later, the delay amount added to the POCSAG signal (encoded signal) by the variable delay units 73 to 76 is the delay amount from the encoding device 70 to each transmitting station 80 ₁ to 80 ₄ is the communication line used for connection. It is set to a value that is corrected so that a portion having a different value depending on the length of 91 to 94 is adjusted to the maximum value.

The coded signals extracted from the variable delay units 73 to 76 are transmitted to the transmitting stations 80 via the communication lines 91 to 94.
₁ via the communication unit 81 ₁ to 81 ₄ of 80 in ₄ machine 8
Is supplied to the 2 _{1-82 4} is modulated in a predetermined modulation scheme,
After being amplified, it is transmitted wirelessly. The mobile receiver 60 is located in any of the service areas of the above-mentioned transmitting stations 80 ₁ to 80 ₄ , and receives and demodulates the transmitted wireless signal.

FIG. 5 is a schematic explanatory view of the above conventional system. In the figure, the same components as those in FIG. 4 are designated by the same reference numerals. In FIG. 5, the calling signal originated by the subscriber 10 becomes a coded signal through the exchange 20 and the coding device 70, and is transmitted through the communication lines 91, 92, 93 and 94 to the transmitting stations 80 ₁ , 80 ₂ , 80. _It is supplied to ₃ and 80 ₄ , modulated and amplified, and transmitted. The mobile receiver 60 receives and demodulates this transmission signal.

Here, the communication lines 91, 92, 93 and 9
Assuming that each of the transmitting stations 80 ₁ , 80 ₂ , 80 ₃ and 8 has a delay amount a, b, c and d of its own, the encoded signals are simultaneously transmitted from the encoding device 70.
Since the coded signal arrives at 0 ₄ after time a, b, c, and d from the above-mentioned transmission time point, each transmitting station 80 ₁ , 80 ₂ ,
When the delay amounts of 80 ₃ and 80 ₄ are set to 0, the coded signals are transmitted to the transmitting stations 80 ₁ , 80 ₂ , 8 at different timings.
0 ₃ and 80 ₄ will be transmitted.

Therefore, the variable delay unit 7 in the encoding device 70 is
3 to 76, the delay amounts a to d of the communication lines 91 to 94
Automatically or manually, the respective delay amounts l, m, and n are set so as to be the maximum delay amount of the delay amounts a to d, for example, b. That is, assuming that the delay amount of the variable delay unit 74 is 0, the delay amount l of the variable delay unit 73 is
Is (b−a), and the delay amount m of the variable delay unit 75 is (b−
c), the delay amount n of the variable delay unit 76 is set to be (b-d).

As a result, the delay amounts of the encoded signals from the encoding device 70 to the transmitting stations 80 ₁ , 80 ₂ , 80 ₃ and 80 ₄ are all b, and when multi-station simultaneous transmission is performed, each transmission is performed. The coded signals are wirelessly transmitted from the stations 80 ₁ , 80 ₂ , 80 ₃ and 80 _{4 at the} same timing.

Therefore, by setting the above-mentioned delay amount, the delay time shown in FIG.
, The transmitting stations 80 ₁ , 80 ₂ , 80 ₃ and 80
_If each service area of ₄ is XI, XII, XIII, and XIV, the overlapping area of service areas XI and XII is XV, and the overlapping area of service areas XIII and XIV is XVI, move in the overlapping area XV. Receiver 6
When 0 is located equidistant from the transmitting stations 80 ₁ and 80 ₂ , respectively, the phase of the encoded signal received by the mobile receiver 60 is the same for both the transmitting stations 80 ₁ and 80 _2. Become. This is the same between the transmitting stations 80 ₃ and 80 ₄ .

Generally, each transmitting station 80 ₁ , 80 ₂ , 80 ₃
, And the phase timing deviation of the coded signal wirelessly transmitted from 80 ₄ is allowed up to ¼ bit of the coded signal. If there is any deviation, the mobile receiver 60 needs to resynchronize the reception synchronization in order to correctly demodulate the coded signal.

From the above, the delay amounts a, b, c and d of the communication lines 91, 92, 93 and 94 between the encoding device 70 and the respective transmitting stations 80 ₁ , 80 ₂ , 80 ₃ and 80 _4. Even if they are different from each other, by setting the corresponding delay amounts in the encoding device 70 so as to match their maximum delay amounts, each transmitting station 80 ₁ , 80 ₂ , 80 ₃ and 80 ₄
Can transmit encoded signals at the same phase timing, and the mobile receiver 60 can receive the same phase timing and different distances even if multiple stations are received at the same distance from each transmitting station. Distance within 1/4 bit (for example, when the transmission rate of the encoded signal is 1200 bps, 62 km (≈ (1/1200) ÷ 4 × 3 × 10 ⁻⁸ ))
Even if there is a difference between, it is possible to receive and demodulate without problems.

[0013]

However, in the above-mentioned conventional mobile communication system, the same number of communication lines as the transmitting stations are required (in FIG. 4 and FIG. 5, the transmitting stations 80 ₁ to 8 1-8).
Since there are 4 stations of 0 _4, the communication lines are 4 of 91-94),
Line usage charges are high, which is a problem for expanding the system scale. In the case of manual operation, the delay amounts of the communication lines 91 to 94 must be measured and the delay amounts of the variable delay units 73 to 76 in the encoding device 70 must be set, but the communication lines 91 to 94 are required. The amount of delay of each transmission station 8 from the encoding device 70
0 ₁ and the route to 80 ₄ may not be uniform, in order to delay the encoder 70 itself is changed due to temperature characteristics, it varies from the maximum delay amount specified. Furthermore, when the delay amounts of the variable delay units 73 to 76 are automatically set, it is necessary to occupy the communication lines 91 to 94 for measuring the delay amounts of the communication lines 91 to 94, and the delay amount may change suddenly. In order to cope with this, there is a problem that the measurement timing of the delay amount must be shortened as much as possible.

The present invention has been made in view of the above points,
An object of the present invention is to provide a mobile communication system in which line usage charges are low, and even if there is a difference in signal delay amount from an encoding device to a transmitting station, wireless signals can be transmitted synchronously from each transmitting station. .

[0015]

In order to achieve the above object, the present invention provides a calling signal by a subscriber's call through an exchange so that the calling signal is lower than a low speed coded signal and a low speed coded signal. An encoding device that encodes a high-speed encoded signal having an encoding speed that is at least twice as high as each other, multiplexes the low-speed encoded signal and the high-speed encoded signal, and outputs the encoded signal, and the encoding device through a communication line. A signal obtained by modulating and amplifying the input multiplex signal is transmitted from a plurality of upper stations, which wirelessly transmit with a predetermined time delay in synchronization with the timing of the signal received by the GPS receiver. The high-speed coded signal in the wireless signal is received, the high-speed coded signal is converted into the low-speed coded signal, and the low-speed coded signal is wirelessly transmitted in synchronization with the timing of the signal received by the GPS receiver. plural And position station, in which a structure having a mobile receiver for receiving a transmission radio signal of the radio signal and the lower station of the low-speed coded signal in a transmission radio signal of the upper station.

Further, the coding apparatus of the present invention comprises a low-speed coding section for coding a calling signal at a coding speed received by a mobile receiver and outputting a low-speed coded signal, and a calling signal from the low-speed coded signal. Also, a high-speed coding unit that codes at a coding speed more than double and outputs a high-speed coded signal, and a low-speed coding unit that sequentially outputs each output coded signal from the low-speed coding unit and the high-speed coding unit A selection unit that outputs a signal obtained by time-sequentially combining the signal and the high-speed encoded signal, and the output time-series combined signal of the selection unit is distributed and supplied to a plurality of upper stations as the multiplex signal via the communication line. By including a distributor, the multiplexed signal can be output.

The plurality of upper stations of the present invention are the first GPS reception device which generates the timing signal at a timing delayed by a delay time larger than the delay amount by the communication line and at a timing synchronized with the reception signal. A control unit that outputs a multiplex signal input via a communication line based on a timing signal, and a first transmitter that wirelessly transmits the output multiplex signal of the control unit. A signal obtained by time-sequentially combining the low-speed encoded signal and the high-speed encoded signal can be wirelessly transmitted in synchronization with the timing signal based on the reception signal of the first GPS receiver.

Further, the plurality of subordinate stations of the present invention generate the timing signal at the timing synchronized with the received signal.
GPS receiver, a receiver for receiving the high-speed encoded signal based on the output timing signal of the second GPS receiver among the wireless transmission signals from a plurality of upper stations, and an output high-speed encoded signal of the receiver To the low speed encoded signal
And a second transmitter that wirelessly transmits the low-speed coded signal synchronized with the low-speed coded signal in the radio transmission signal of the higher-level station. It is preferable because it can be transmitted.

[0019]

According to the present invention, a calling signal from a subscriber's call is encoded into a low speed encoded signal and a high speed encoded signal by an encoding device, and the low speed encoded signal and the high speed encoded signal are multiplexed. The multiplexed signal is output, modulated and amplified by multiple upper stations, and the signal is delayed by a predetermined time in synchronization with the timing of the signal received by the GPS receiver and wirelessly transmitted. The encoded signal is received and converted into a low speed encoded signal, and the converted low speed encoded signal is wirelessly transmitted in synchronization with the timing of the signal received by the GPS receiver, so that the mobile receiver transmits the upper station. Since the low-speed encoded signal in the radio signal and the low-speed encoded signal of the transmission radio signal of the lower station are received, the difference in the communication line delay amount between the encoding device and each upper station and the difference between each upper station Between each subordinate station Even if there is difference in radio propagation delay, G
It is possible to wirelessly transmit synchronized low-speed encoded signals from the upper station and the lower station having the first and second GPS receivers synchronized with the PS system, respectively.

Further, according to the present invention, a part of the transmission signal of the upper station is received by the lower station as a high speed coded signal, and the lower station converts it into a low speed coded signal. You can communicate with lower stations without installing a wired communication line.

[0021]

EXAMPLES Next, examples of the present invention will be described. FIG. 1 shows a block diagram of an embodiment of the present invention. In the figure, the same components as those in FIG. 4 are designated by the same reference numerals. In the embodiment shown in FIG. 1, an exchange 20 for switching and outputting call signals originated by a large number of subscribers 10, and a communication line 21 from the exchange 20.
An encoding device 30 that encodes the above-mentioned call signal input via the wireless call signal, and a transmitting station that wirelessly transmits the wireless call signal supplied from the encoder device 30 via the communication lines 96 and 97. 40 ₁ , 40 ₂ ,
50 ₁ and 50 ₂ and is configured to cause the intended mobile receiver 60 to receive a calling signal from the subscriber 10. The encoding device 30 constitutes the central station A, the transmitting stations 40 ₁ and 40 ₂ constitute the upper station B, and the transmitting station 50 ₁
And 50 _{2 form} the subordinate station C.

The coding device 30 described above includes a high-speed coding unit 31 which codes the calling signals at a predetermined coding speed.
And the low-speed encoding unit 32, and the encoding units 31 and 32.
Of the output signal of the selection unit 33, and a distribution unit 34 that divides the output coded signal of the selection unit 33 into two. The above-mentioned high-speed coding unit 31 performs coding at a coding speed that is at least twice the coding speed of the low-speed coding unit 32.

Further, the transmitting station 4 which constitutes the above-mentioned upper station B
0 ₁ and 40 ₂ have the same configuration, and GPS receivers 41 ₁ and 41 ₂ that generate the transmission timing of the encoded signal,
Control units 42 ₁ and 42 having a delay function for transmitting an encoded signal according to the information of the GPS receivers 41 ₁ and 41 _2.
2 and transmitters 43 ₁ and 43 ₂ that modulate / amplify this coded signal and send out a radio signal, and are connected to the coding device 30 via communication lines 96 and 97.

Further, the transmitting station 5 which constitutes the above-mentioned lower station C
0₁ And 50₂ Have the same configuration, and the radio signal of the upper station B is
GPS receiver 51 for controlling the reception timing of the signal₁ 5,
1₂And the radio signal of the upper station B is received and demodulated to obtain a coded signal.
Receiver 52₁ , 52 ₂ And GPS receiver 51
₁ , 51₂ Depending on the output information of the receiver 52₁ , 52₂
Low-speed coding by transmitting, modulating and amplifying the output coded signal of
Transmitter 53 for wirelessly transmitting signals₁ , 53₂ Composed of and
Has been. The mobile receiver 60 receives the above low-speed encoded signal.
Believe.

[0025] As described above, in this embodiment, by using the GPS receiver 41 _1, 41 ₂ and 51 _1, 51 _2, satellites US developed, global positioning consisting of ground tracking and control system System (GPS: Global
The transmission frequency from the artificial satellite synchronized with the frequency at which the atomic clock of the artificial satellite in Positioning System oscillates is received.

Further, in this embodiment, as shown in FIG.
The transmitting stations 40 ₁ , 50 ₁ , 40 ₂ and 50 ₂ have service areas I, II, III and IV, respectively, and the mobile receiver 60 is located in a service area V where service areas I and II overlap. I shall. Also, service areas III and IV
There are service area VIs that overlap.

Next, the operation of this embodiment will be described.
The encoding device 30 is selected by the exchange 20 according to the signal originated by the subscriber 10, and the encoding device 3 is selected via the communication line 21.
Connected to 0. As a result, the calling signal from the subscriber 10 is transmitted to the encoding device 30 via the exchange 20 and the communication line 21.
Are supplied to the high-speed encoding unit 31 and the low-speed encoding unit 32, respectively, and are encoded.

The high-speed encoding unit 31 and the low-speed encoding unit 32 respectively input the input call signal to the radio call signal, for example, the POC.
Encode to SAG signal. FIGS. 3A and 3B show examples of the output coded signals of the high speed coding unit 31 and the low speed coding unit 32, respectively. As shown by 1 to 8 in FIG. 3A, the output encoded signal of the high speed encoding unit 31 is, for example, “
An 8-bit pattern of 1,0,1,1,0,0,1,0 "and an output coded signal of the low speed coding unit 32 is shown in FIG.
As shown by 1 ′ to 8 ′ in (B), the pattern is the same as the output coded signal of the high speed coding unit 31, but the coding speed is 1/2 times or less (for example, 1200 bps).

The output coded signals of the high speed coding unit 31 and the low speed coding unit 32 are supplied to the selection unit 33, respectively, and as shown in FIG. 3C, the high speed coding signal and the low speed coding signal. Are sequentially selected so as to be time-sequentially sandwiched by the guard sections, that is, selected sequentially in the order schematically shown in FIG. 3D, and the low-speed encoded signal is delayed and extracted. Here, the guard unit is set to be equal to or more than a radio propagation delay amount described later. The distribution unit 34 divides the time-series combined signal (time division multiplexed signal) extracted from the selection unit 33 into _two , and controls the control units 42 ₁ in the transmitters 40 ₁ and 40 ₂ via the communication lines 96 and 97, respectively. , 42 ₂ in parallel.

On the other hand, the GPS receivers 41 ₁ and 41 ₂ have the time accuracy (± 1 μs with respect to the standard time) composed of the atomic clock of the artificial satellite of the GPS system and the atomic clock of the tracking control station on the ground, respectively. By utilizing this, a highly accurate timing signal shown in FIG. 3 (E) is generated. Here, assuming that the respective delay amounts of the communication lines 96 and 97 between the encoding device 30 and the upper transmitting stations 40 ₁ and 40 ₂ are α, the distribution unit 34 in the encoding device 30 described above. The time-series combined signal shown in FIG.
Is delayed by only the control unit 42 in the transmitters 40 ₁ and 40 ₂ .
₁ and 42 ₂ , respectively.

Now, at a time later than the delay amount α, the above G
Assuming that the PS receivers 41 ₁ and 41 ₂ output timing signals, the control units 42 ₁ and 42 ₂ output the input time-series combined signals to the transmitters 43 ₁ and 43 _{2 in} synchronization with the timing. As a result, the transmitter 43
Reference numerals ₁ and 43 ₂ modulate and amplify the time-series combined signals input as shown in FIG. 3 (F) and transmit them as radio signals. Therefore, this wireless signal has a pattern as schematically shown in FIG.

The GPS receivers 51 ₁ and 51 ₂ are the above-mentioned G
A timing signal as shown in FIG. 3 (L) having a timing synchronized with the output timing signals of the PS receivers 41 ₁ and 41 ₂ is generated, and the timing signal shown in FIG.
A receiver timing signal shown in FIG.
Supplies, respectively 2 ₁ and 52 ₂ to respectively supply the transmitter 53 ₁ and 53 ₂ to generate a transmitter timing signal shown in Figure 3 of the receiver timing signal and reversed-phase (K).

The receivers 52 ₁ and 52 ₂ are turned on during the high level period of the above receiver timing signal and controlled to be off during the low level period. Similarly, transmitters 53 ₁ and 5
3 ₂ is a high level period of the above transmitter timing signal,
It is turned on and controlled to be off during the low level period. Therefore, the receivers 52 ₁ and 52 ₂ and the transmitters 53 ₁ and 53 ₂
When one of them is on, the other is off.

Here, assuming that the radio propagation delay amount from the transmission stations 40 ₁ and 40 ₂ to the transmission stations 50 ₁ and 50 ₂ is p, the output signals of the receivers 52 ₁ and 52 ₂ are shown in FIG. 3 (I). As described above, the transmission outputs of the transmission stations 40 ₁ and 40 ₂ become signals delayed by the time p, and the output pattern is shown in FIG.
It is schematically shown in (H). In addition, in FIG. 3 (I), the signal portions shown by the broken lines are in the ON state and the transmitter stations 40 ₁ and 40 which are upper stations although the receivers 52 ₁ and 52 ₂ are in the OFF state, respectively. The timing when the wireless signal from ₂ is received is shown for reference.

Therefore, when the receivers 52 ₁ and 52 ₂ are respectively turned on, the transmitting stations 40 ₁ and 40 ₂
The wireless signal of the high-speed coded signal transmitted with a delay of time p from is received from the receiver 5 by this.
High-speed encoded signals are supplied from 2 ₁ and 52 ₂ to transmitters 53 ₁ and 53 ₂ . The transmitters 53 ₁ and 53 ₂ convert the input received high-speed encoded signal into a low-speed encoded signal, and then are supplied from the GPS receivers 51 ₁ and 51 ₂ .
Modulation / amplification is performed in synchronization with the timing signal as shown in (L), and the low speed coded signal is wirelessly transmitted as shown in FIG. 3 (M). The transmitter output pattern at this time is shown in FIG.
Is schematically shown. Therefore, the mobile receiver 60 simultaneously receives the low speed coded signal when it is equidistant from each transmitting station.

Next, the multi-station simultaneous transmission system of this embodiment will be described with reference to FIG. In the figure, the same components as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted. In FIG. 2, as described above, the call signal originated from the subscriber 10 becomes the high speed coded signal and the low speed coded signal via the exchange 20 and the coding device 30, and the communication lines 96 and 9
7 is supplied to each transmitting station 40 ₁ and 40 ₂ , modulated / amplified and wirelessly transmitted here, and further received by the transmitting stations 50 ₁ and 50 ₂ to convert the high-speed encoded signal into a low-speed encoded signal. It is post-modulated, amplified, and transmitted wirelessly. The mobile receiver 60 receives and demodulates the low-speed encoded signal in the wireless transmission signals transmitted by the transmission stations 40 ₁ and 40 ₂ or the low-speed encoded signal transmitted by the transmission stations 50 ₁ 50 ₂ .

Here, assuming that the delay amounts peculiar to the communication lines 96 and 97 are x and y, if the coded signals are simultaneously sent from the coding device 30, the time is passed from the transmitting stations 40 ₁ and 40 ₂ to the time x and y. Since the encoded signal arrives, each transmitting station 40
_When the delay amounts of ₁ and 40 ₂ are set to 0, the coded signals are transmitted from the transmitting stations 40 ₁ and 40 ₂ at different timings.

However, in the present embodiment, even if the delay amounts x and y change to arbitrary values within the value of the delay amount α, the transmitters 43 ₁ and 43 in the transmitting stations 40 ₁ and 40 _{2 will have} . ₂ is GP
Based on the same timing signals from the S receivers 41 ₁ and 41 ₂ , as shown in FIGS. 3 (F) and 3 (G), the inputted time-series combined signals are modulated / amplified to be radio signals simultaneously at the same timing. Can be sent.

Further, the radio propagation delay amount from the transmitting station 40 ₁ to the transmitting station 50 ₁ is q, and the transmitting station 40 ₂ to the transmitting station 5
Assuming that the radio propagation delay amount up to 0 ₂ is r, even if these radio propagation delay amounts fluctuate to arbitrary values within the value of p, the transmitters 53 ₁ in the transmitting stations 50 ₁ and 50 ₂ , 5
3 ₂ based on the GPS receiver 41 _1, 41 ₂ of the output timing signal of the same timing signal from the GPS receiver 51 _1, 51 ₂ Figure 3 (M), as shown in (N), the input low speed coding A signal can be modulated and amplified and simultaneously transmitted as a radio signal at the same timing.

Therefore, as shown in FIG. 2, the mobile receiver 6
It is assumed that 0 is located in the service area V where the service area I of the transmitting station 40 _{1 and} the service area II of the transmitting station 50 ₁ overlap, and the position equidistant from the transmitting station 40 ₁ and the transmitting station 50 _1. , The phase of the low speed encoded signal received by the mobile receiver 60 is the same for the signals transmitted from both the transmitting station 40 ₁ and the transmitting station 50 ₁ . This means that the mobile receiver 60 is located in the service area VI in which the service area III of the transmitting station 40 _{2 and} the service area IV of the transmitting station 50 ₂ overlap, and the transmitting station 40 ₂ and the transmitting station 50 ₂ The same is true when they are equidistant from.

As described above, according to this embodiment, the low-speed encoded signal output from the encoder 30 is converted into the low-speed encoded signal as a high-speed encoded signal having a transmission rate twice or more that of the low-speed encoded signal normally used. Time-sequential synthesis is performed, and 1/3 of the data length of the output signal (when the transmission rate of the high-speed encoded signal including the guard part is twice that of the low-speed encoded signal) is used, and G
The PS receiver is connected to each transmitting station 40 ₁ , 40 ₂ , 50 ₁ and 50.
_When used in ₂ , multi-station simultaneous transmission can be performed between the upper station B and the lower station C without installing a communication line from the encoding device 30 to the transmitting stations 50 ₁ and 50 ₂ which are the lower station C. it can.

The present invention is not limited to the above embodiment, the upper station B and the lower station C may have a number of stations other than two, and the upper station B and the lower station C have the same number. Of course, it does not have to be.

[0043]

As described above, according to the present invention,
The difference in the communication line delay amount between the encoding device and each upper station,
Even if there is a difference in the amount of radio propagation delay between each upper station and each lower station, the first and second GPS synchronized with the GPS system
Since wireless transmission of synchronized low-speed encoded signals can be performed from upper and lower stations each having a receiver,
Since it is not necessary to measure the delay amount of the line, it is not necessary to use the communication line for measuring the delay amount, and synchronized multi-station simultaneous transmission can be performed between the upper station and the lower station.

Further, according to the present invention, a part of the transmission signal of the upper station is received by the lower station as a high speed coded signal, and the lower station converts it into a low speed coded signal. Since it is possible to communicate without installing a wired communication line between the two, it is possible to reduce the line usage fee by the number of lower-level stations compared with the conventional system, and as the system scale increases, the cost will be lower than the conventional system. An advantageous mobile communication system can be constructed.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is a schematic explanatory diagram of an embodiment of the present invention.

FIG. 3 is a time chart for explaining the operation of the embodiment of the present invention.

FIG. 4 is a configuration diagram of a conventional example.

FIG. 5 is a schematic explanatory view of a conventional example.

[Explanation of symbols]

10 subscribers 20 exchanges 30 encoders 31 high-speed encoders 32 low-speed encoders 33 selectors 34 distributors 40 ₁ , 40 ₂ transmitter stations 41 ₁ , 41 ₂ , 51 ₁ , 51 _{2 which are} upper stations GPS receivers 42 ₁ , 42 ₂ Control unit 43 ₁ , 43 ₂ Transmitter 50 ₁ , 50 ₂ Lower station transmitter station 52 ₁ , 52 ₂ Receiver 53 ₁ , 53 ₂ Transmitter 60 Mobile receiver A Central station B Upper station C Lower station

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H04Q 7/24 7/26 7/30 H04Q 7/04 A

Claims (4)

[Claims] 1. A calling signal from a subscriber's call is supplied through a switch, and the calling signal is a low-speed encoded signal and a high-speed encoded signal whose encoding speed is at least twice as high as that of the low-speed encoded signal. And an encoding device for encoding and outputting the low-speed encoded signal and the high-speed encoded signal, and a modulated signal obtained by modulating and amplifying the multiplexed signal input from the encoding device through the communication line. A plurality of upper stations that wirelessly transmit the received signal by delaying for a predetermined time in synchronization with the timing of the signal received by the GPS receiver, and receive a high-speed encoded signal in the wireless signal transmitted from the plurality of upper stations. Then, after converting the high-speed encoded signal to the low-speed encoded signal, a plurality of lower stations that wirelessly transmit the low-speed encoded signal in synchronization with the timing of the signal received by the GPS receiver, and the upper station. In the transmitted radio signal A mobile communication system comprising: a mobile receiver for receiving a radio signal of a low speed coded signal and a transmission radio signal of the lower station. 2. The encoding device encodes the calling signal at a coding rate received by the mobile receiver and outputs a low speed encoded signal, and a low speed encoding unit for the calling signal. A high-speed encoding unit that outputs a high-speed encoded signal by encoding at an encoding speed that is at least twice that of a signal, and sequentially outputs each output encoded signal from the low-speed encoding unit and the high-speed encoding unit A selection unit that outputs signals obtained by time-sequentially combining the low-speed encoded signal and the high-speed encoded signal,
The mobile communication system according to claim 1, further comprising: a distribution unit that distributes and supplies the output time-series combined signal of the selection unit to the plurality of upper stations as the multiplex signals via the communication line. 3. The plurality of upper stations, at a timing delayed by a delay time larger than the delay amount by the communication line,
A first GPS receiver that generates a timing signal at a timing synchronized with the received signal, a control unit that outputs a multiple signal input via the communication line based on the timing signal, and a controller of the control unit. The mobile communication system according to claim 1 or 2, further comprising a first transmitter that wirelessly transmits the output multiplex signal. 4. The second GPS that generates a timing signal at a timing synchronized with a received signal by the plurality of lower stations.
A receiver, a receiver that receives the high-speed encoded signal based on an output timing signal of the second GPS receiver among radio transmission signals from the plurality of upper stations, and an output high-speed encoding of the receiver 4. A second transmitter for converting a signal into the low-speed encoded signal and wirelessly transmitting the signal based on an output timing signal of the second GPS receiver, respectively. The mobile communication system according to claim 1.