JPH10145845A - Mobile communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct a phase shift due to a timewise difference in delays through communication lines among base stations without setting timewise delas in advance. SOLUTION: GPS receivers 41, 51, 61 receive a GPS radio wave and generate timing signals 46, 56, 66 based on time information included in the GPS radio wave and delay sections 42, 52, 62 delay the signals by processing value to obtain delayed timing signals 47, 57, 67. In order to synchronize a radio call signal received via communication channels 31, 32, 33 with the delayed timing signals 47, 57, 67 by synchronization sections 44, 54,64, the signal is synchronized among base stations 40, 50, 60. Thus, the synchronization among the base stations 40, 50, 60 is kept without setting the time delay in advance.

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 calling a mobile receiver by radio.

[0002]

2. Description of the Related Art Conventionally, in a mobile communication system for calling a mobile receiver by radio, a plurality of base stations simultaneously transmit the same signal on the same radio channel while adjusting the phase of a modulated signal. In order to adjust the phase of the modulated signal at each base station, for example, Japanese Patent Publication No. 63-13374 discloses a method of providing a delay circuit to correct a time delay difference of an approach line or to transmit data to each base station. A technique is described in which a start pattern is included in a signal and used as a reference signal.

[0003] Figure 4 is a block diagram of the conventional mobile communication system, Figure 5 is a block diagram of a base station 9 ₁ in FIG.

[0004] This conventional mobile communication system includes a central station 8.
0, and a plurality of base stations 9 ₁ to 9 _n, the central station 80 and the base station 9
₁ between and composed approach line 8 ₁ to 8 _n connecting between the base stations 9 ₁ to 9 _n. In the conventional mobile communication system, the first transmitted signal to approach the line ₈₁ from the central station 80 the base station 9 _1, 9 _2, via ..., reaches the base station 9 _n.

[0005] The base station 9 ₁ as shown in FIG. 5, the line amplifier section 101, a delay correction unit 102, a pattern detection unit 104, a tone oscillation unit 106, a phase synchronization unit 10
5, the transmitter 103, and the antenna 107.

[0006] Line amplifier unit 101 outputs to the approach line ₈₂ as the delay correction unit 102 amplifies the signal input through the approach line 8 _1.

The delay correction unit 102 delays the input signal by a predetermined delay time and outputs the signal.

The pattern detecting section 104 detects a start pattern included in the input signal, generates a pulse output, and outputs the pulse output.

[0009] The tone oscillating section 106 outputs a tone signal that has been independently synchronized and oscillated.

The phase synchronizing section 105 includes a tone oscillating section 106
Are phase-corrected by the pulse output output from the pattern detection unit 104 and output.

[0011] The transmitter 103, when the signal sent from the approach line ₈₁ is a data signal, a radio wave and the modulation signal output of the delay correction section 102 transmits by the antenna 107, is signal sent In the case of a tone signal, a radio wave obtained by modulating the signal output from the phase synchronization unit 105 is transmitted from the antenna 107.

The base stations 9 _{2 to} 9 _n have the same configuration and operation as those of the base station 9 _1, and thus the description is omitted.

[0013] In this conventional mobile communication system, each base station between 9 ₁ to 9 _n to detect the specific pattern of the data signal are the same phase, and performs phase correction of the transmission signal by the detection output.

[0014] Therefore, even in the case of transmission to match the phases of a plurality of signals from a plurality of base stations 9 ₁ to 9 _n connected by approach line 8 ₁ to 8 _n, Boost approach line between base stations There is no need, and there is no need to add a circuit for delay adjustment.

In this conventional mobile communication system,
Time delay differences between the base stations 8 ₁ to 8 _n measured in advance, but to set the delay amount so as to correct the time delay amount difference in the delay correcting unit 102.

[0016] Therefore, the delay amount of each base station 9 ₁ to 9 _n becomes the same, the phase of the signal transmitted from the base station 9 ₁ to 9 _n coincide.

[0017]

The above-mentioned conventional mobile communication system has the following problems. (1) Since there is no reference signal for adjusting the phase difference of the data signal between the base stations, it is necessary to set the delay time of the delay correction unit in advance so that the phase of the data signal matches for each base station. is there. (2) Since there is no means for absorbing a change in the time delay of the approach line, if the time delay of the approach line changes with time, the phases of the data signals of the respective base stations will not match. . (3) When transmitting a tone signal, each base station does not have a reference signal that defines the tone signal transmission time, so it is necessary to include a start pattern in the data signal, and the signal utilization is reduced.

An object of the present invention is to provide a mobile communication system capable of correcting a phase shift due to a difference in a time delay caused by a communication line such as an approach line between base stations without previously setting a time delay. Is to provide.

[0019]

In order to achieve the above object, a mobile communication system according to the present invention is provided with an exchange for switching and outputting a call signal originated by a subscriber, and an input from the exchange via a communication line. An encoding device that encodes the paging signal to be output as a radio paging signal, and a phase of the radio paging signal supplied from the encoding device via a communication line by time information included in a received GPS radio wave. It has a plurality of base stations that control and transmit, and a mobile receiver that receives radio waves transmitted by the base stations.

According to the present invention, a GPS radio wave is received by a GPS receiver, and a radio call signal between base stations is synchronized based on time information contained in the GPS radio wave.

Therefore, it is not necessary to preset a delay time for correcting the time delay caused by the communication line for each base station. Can maintain synchronization of the wireless paging signal.

According to an embodiment of the present invention, the base station outputs a timing signal serving as a time reference when outputting the radio paging signal based on time information included in the received GPS radio wave. A setting unit that outputs a signal that sets a delay time for delaying the timing signal; a delay unit that delays the timing signal by a setting of a signal output by the setting unit and outputs the delayed signal as a delayed timing signal; A synchronization unit that synchronizes the radio paging signal supplied from the communication device via the communication line with the delay timing signal and outputs the transmission signal as a transmission signal, and a transmitter that modulates and amplifies the transmission signal and outputs the transmission signal as a radio signal. Have.

According to an embodiment of the present invention, the setting unit sets a delay time for each of the base stations in accordance with the size of the service area of each of the base stations.

According to the present invention, the delay time for delaying the timing signal output from the GPS receiver can be set in the setting unit for each base station, so that the transmission outputs of two or more base stations are different. The demodulated signal of the mobile receiver can be synchronized even if the area of the service area is different due to the reason and the amount of time delay from each base station to the overlap area where the two service areas overlap is different. .

[0025]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of a mobile communication system according to an embodiment of the present invention, FIG. 2 is a schematic explanatory diagram of the mobile communication system of FIG. 1, and FIG. 3 is a timing chart showing the operation of the mobile communication system of FIG. is there.

As shown in FIG. 1, in the mobile communication system of the present embodiment, an exchange 20 for switching and outputting paging signals originating from a plurality of subscribers 10 and an input from the exchange 20 via a communication line 21 are provided. Encoding device 30 for encoding a paging signal to be output as a radio paging signal, and a time period included in the received GPS radio wave to transmit a radio paging signal supplied from encoding device 30 via communication lines 31, 32, and 33. Base station 4 for transmitting a phase controlled by information
0, 50, and 60, and a mobile receiver 70 that receives radio waves transmitted by the base stations 40, 50, and 60.

This embodiment is a system for causing a target mobile receiver 70 to receive a call signal from a subscriber 10.

The base station 40 further includes a GPS receiver 41 for outputting a timing signal 46 serving as a time reference when outputting the radio paging signal based on time information included in the received GPS radio wave, and a timing signal 46. A setting unit 43 that outputs a signal for setting a delay time to be delayed; a delay unit 42 that delays the timing signal 46 by a setting of the signal output by the setting unit 43 and outputs the result as a delay timing signal 47; It comprises a synchronization section 44 for synchronizing the input radio calling signal with the delay timing signal 47 and outputting the same, and a transmitter 45 for modulating / amplifying the transmission signal 48 output from the synchronization section 44 and outputting the signal as a radio signal.

The base station 50 and the base station 60 have the same configuration as the base station 40, and the GPS receivers 51 and 61
The delay units 52 and 62 correspond to the PS receiver 41,
2, the setting units 53 and 63 correspond to the setting unit 43,
The synchronization units 54 and 64 correspond to the synchronization unit 44, and the transmitters 55 and 64
Reference numeral 65 corresponds to the transmitter 45, and its configuration and operation are the same, and a description thereof will be omitted.

As described above, in the present embodiment, by using the GPS receivers 41, 51, and 61, a global positioning system (GPS) composed of an artificial satellite developed by the United States and a terrestrial tracking control system is used.
The transmitting radio wave is synchronized with the oscillation frequency of the atomic clock of the artificial satellite in the oning system.

In this embodiment, as shown in FIG. 2, the base station 40, the base station 50, and the base station 60 have service areas 1, 2, and 3, respectively, and the service areas 1 and 2 overlap. The range is referred to as service area 4 and the overlapping range of service areas 2 and 3 is referred to as service area 5. Here, it is assumed that the mobile receiver 70 exists in these service areas 1 to 5. Here, the service areas 1 and 2 have the same size, and the service area 4
Inside, there is a boundary point between the service area 1 and the service area 2 at a point equidistant from the base station 40 and the base station 50. Therefore, when the time delay between the boundary point and the base station 40 is k, and the time delay between the boundary point of the service area and the base station 50 is l, k = 1. Here, the service area 3 is smaller than the service area 2 because the transmission power of the base station 60 is smaller than the transmission power of the base station 50. At this time, the service area 5
If the time delay between the boundary point between the service areas 2 and 3 and the base station 50 is m and the time delay between the base station 60 and the base station 60 is n, then m> n.

The mobile receiver 70 is located in the service area 4
A signal obtained by demodulating the transmission radio wave from the base station 40 at the boundary point between the service area 1 and the service area 2 in the reception signal 201 and a signal obtained by demodulating the transmission radio wave from the base station 50 are received. The signal 202 is assumed.

Similarly, at the boundary point between the service area 2 and the service area 3 in the service area 5, the mobile receiver 70 demodulates the radio wave transmitted from the base station 50 to obtain a reception signal 203, A signal obtained by demodulating a transmission radio wave from the station 60 is referred to as a reception signal 204.

Next, the operation of this embodiment will be described with reference to FIGS. 1, 2 and 3.

When the subscriber 10 makes a call, the signal is input to the exchange 20, the encoding device 30 is selected, and the encoding device 30 is connected via the communication line 21. Thus, the signal originated by the subscriber 10 is supplied to the encoding device 30 via the exchange 20 and the communication line 21, and is encoded and output as a radio call signal.

The output radio paging signal is distributed to the base station 4 via the communication lines 31, 32 and 33.
0, the base station 50, and the base station 60. At this time,
Assuming that the time delay amounts of the communication lines 31, 32, and 33 are α, β, and γ, respectively, the head of the encoded radio paging signal data 0 is A, B, and C of the base stations 40, 50, and 60.
The timing of reaching each point is as shown in FIG.

On the other hand, the GPS receivers 41, 51, 61
Utilizing the time accuracy (± 1 μs with respect to the standard time) constituted by the atomic clock of the satellite of the GPS system and the atomic clock of the tracking control station on the ground, the timing signals 46 and 56 and 66 are generated.

The delay times of the delay units 42, 52 and 62 are set by setting units 43, 53 and 63, respectively. Here, since k = 1, the time delay amount of the delay units 42 and 52 is 0.
Is set to The delay time of the delay unit 62 is set to mn because m> n. Therefore, the delay units 42, 5
2 and 62 output delay timing signals 47, 57 and 6
7 is output at the timing shown in FIG.

The synchronization units 44, 54 and 64 are connected to the communication line 3
The coded radio paging signals input from 1, 32 and 33 are respectively converted into delayed timing signals 47, 57 and 6
7 is synchronized with the falling edge of the transmission signal 48, 58, 6
Output as 8. The transmitters 45, 55 and 65 modulate and amplify the transmission signals 48, 58 and 68, respectively, and transmit them as radio signals.

Here, as shown in FIG.
A case where 0 is in the service area 4 where the service area 1 of the base station 40 and the service area 2 of the base station 50 overlap will be described. The time delay amounts from the base station 40 and the base station 50 to the service area 4 are k and l, respectively.
Therefore, the demodulated signal of the mobile receiver 70 is included in the base station 4
The signals of the received signals 201 and 202 in FIG. 3 which are delayed by k and l respectively from the signals transmitted by 0 and 50 are obtained. That is, the mobile receiver 70 can receive the signals from the base stations 40 and 50 in the same phase.

Similarly, mobile receiver 70 is connected to base station 50.
Service area 2 and base station 60 service area 3
Is present in the overlapping service area 5. Since the time delay from the base station 50 to the service area 5 is m and the time delay from the base station 60 is n, the demodulated signal of the mobile receiver 70 includes the base station 50,
The signals of the received signals 203 and 204 of FIG. 3 which are delayed by m and n, respectively, from the signal transmitted by 60 are obtained. Here, since base station 60 has transmitted a signal delayed by mn from base station 50 in advance, mobile receiver 70 can receive signals from base stations 50 and 60 in phase.

[0043]

As described above, the present invention has the following effects. (1) Since the means for synchronizing between the base stations is provided based on the time information included in the GPS radio wave, even if the time delay due to the communication line between the base stations is not set in advance, the communication between the base stations can be performed. Signals are kept synchronized. (2) Since the means for synchronizing the base stations with the time information included in the GPS radio wave is provided, it is possible to automatically absorb the change in the amount of time delay due to the communication line. (3) Since a means for setting the delay time of the reference signal output from the GPS receiver is provided for each base station, the service area has a different width due to a difference in the transmission output of the base station and the like. Even if the time delay is different, the demodulated signal of the mobile receiver can be synchronized.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a mobile communication system according to an embodiment of the present invention.

FIG. 2 is a schematic explanatory diagram of the mobile communication system of FIG.

FIG. 3 is a timing chart showing an operation of the mobile communication system of FIG.

FIG. 4 is a configuration diagram of a conventional mobile communication system.

5 is a block diagram of a base station 9 ₁ in FIG.

[Explanation of symbols]

1-5 service area 10 subscriber 20 exchange 21 communication line 30 coding device 31,32,33 communication line 40,50,60 base station 41,51,61 GPS receiver 42,52,62 delay unit 43,53, 63 setting unit 44, 54, 64 synchronization unit 45, 55, 65 transmitter 46, 56, 66 timing signal 47, 57, 67 delay timing signal 48, 58, 68 transmission signal 70 mobile receiver 80 central station 8 ₁ to 8 _n approach line 9 ₁ to 9 _n base station 101 line amplifier 102 delay correcting unit 103 transmitter 104 pattern detecting unit 105 phase synchronization unit 106 tone oscillator section 107 antenna 201 to 204 receive signals

Claims (3)

[Claims] An exchange for switching and outputting a call signal originated by a subscriber; an encoding device for encoding the call signal input from the exchange via a communication line and outputting the encoded signal as a wireless call signal; A plurality of base stations for controlling the phase of the radio paging signal supplied from the encoding device via a communication line by controlling the phase based on time information included in the received GPS radio waves, and transmitting the radio waves transmitted by the base station. A mobile communication system having a mobile receiver for receiving. 2. A GPS, wherein the base station outputs a timing signal serving as a time reference when outputting the radio paging signal based on time information included in a received GPS radio wave.
A receiver, a setting unit that outputs a signal that sets a delay time for delaying the timing signal, and a delay unit that delays the timing signal by a setting of the signal output by the setting unit and outputs the signal as a delayed timing signal. A synchronization unit that synchronizes the radio paging signal supplied from the encoding device via a communication line with the delay timing signal and outputs the transmission signal as a transmission signal; and a transmission that modulates and amplifies the transmission signal and outputs the transmission signal as a radio signal. The mobile communication system according to claim 1, further comprising a communication device. 3. The mobile communication system according to claim 1, wherein the setting unit sets a delay time for each of the base stations in accordance with a size of a service area of each of the base stations.