JP3307451B2 - Wireless paging method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to the transmission of signals between a central office and peripheral offices in a mobile communication system. In particular, the present invention relates to a process of receiving a call signal from a central office in a peripheral office in a wireless calling system.

[0002]

2. Description of the Related Art As shown in FIG. 1, for example, a system in a radio paging system has a central office 1 and a plurality of n peripheral offices 3 (3-1, 3-1) to which a paging signal from this central office is transmitted. 3-i,
3-j, 3-n) are duplicated trunk lines 2-1-1 to 2-1-1
This is a configuration connected via n-2. Each peripheral station 3 transmits a paging signal transmitted from the central station at the same frequency to each area, and performs paging of the radio paging receiver. Here, a wired line, a wireless line, a satellite line, or the like is used as the relay line 2.

FIG. 2 is a block diagram showing the configuration of the central office 1 and the peripheral office 3. The central office 1 includes a call signal encoding unit 4
And performs error correction coding on the call signal and transmits the call signal to each peripheral station 3. The call signal transmitted from the central office 1 is transmitted to the peripheral offices 3-1 to 3-n via the respective trunk lines 2-1-1 to 2-n-2. The peripheral station 3 includes a phase compensator 5 for each relay line, a selector 6 for selecting an output of the phase compensator, and a transmitter 7. One of the peripheral stations 3
Looking at -1, one peripheral station 3-1 performs the phase compensation of the paging signal received by the phase compensators 5-1 and 5-2 corresponding to the respective trunk lines. The paging signal received by the trunk line 2-1-1 by the selection unit 6 and the trunk line 2-1-2
Then, the selected paging signal is selected, and the selected paging signal is modulated and amplified by the transmission section 7 and transmitted to the mobile communication radio line by the antenna 8. The selector 6 selects another trunk line serving as a protection line in the event of a line failure or device failure.

FIG. 3 shows the structure of a call signal. As shown in FIG. 3A, the call signal is formed by connecting n group signals having a signal length t. As shown in FIG. 3B, each group signal is composed of a synchronization signal and k ringing signals to receivers belonging to this group, and each ringing signal is an address signal which is a subscriber identification signal. And a message signal following the address signal. Further, as shown in FIG. 3 (3), the address signal and the message signal are each composed of address information and message information, and an error correction code word obtained by adding a check bit to this information. By performing the error correction coding, high-quality signal transmission is realized even in a fading mobile communication transmission path. Note that the calling signal includes a case where only an address signal for making a call is used.

[0005]

However, in such a radio paging system, if the quality of the trunk line is temporarily deteriorated, or if the detection of the line failure or the equipment failure is delayed, the paging signal is transmitted by the mobile communication system. There is a problem that an error occurs in a call signal in a trunk line before transmission to a channel. At this time, there is also a method of applying error control only to the trunk line section, but in this case, there is a problem that the system becomes complicated.

SUMMARY OF THE INVENTION The present invention provides a radio paging system constituted by a plurality of peripheral stations connected from a central station via a relay line to reduce errors occurring in the relay line, thereby providing a high quality radio paging system. The purpose is to provide.

[0007]

SUMMARY OF THE INVENTION A first aspect of the present invention is as follows.
The central office and at least two distributed peripheral offices
The central station is connected via the above trunk line, and transmits, to each of the peripheral stations, a call signal in which information including an address designating a called receiver is error-correction-coded via the trunk line. Wherein each of the peripheral stations comprises a means for transmitting the paging signal at the same frequency after the received paging signal is phase-synchronized, wherein each of the peripheral stations establishes the respective relay line. Two or more error correction decoding means for performing error correction decoding of the paging signal received via the communication apparatus, two or more error correction coding means for error correction coding the paging signal decoded by the error correction decoding means, Selecting means for selecting and outputting any of the outputs of the error correction encoding means.

When each of the peripheral stations fails to decode correctly by the error correction decoding means, it selectively synthesizes an error correction codeword obtained by performing error correction coding on a call signal successfully decoded by the other error correction decoding means. Output means.

A second aspect is that a central office and a plurality of peripheral stations distributed are connected via at least two or more trunk lines, and the central office receives a called reception via the trunk line. Means for transmitting to each of the peripheral stations a call signal comprising an error-correcting codeword in which information including an address designating the error-correcting code has been encoded, wherein each of the peripheral stations has synchronized the received calling signal with a phase. Thereafter, in a radio paging system including means for transmitting the paging signal at the same frequency, each peripheral station performs two or more error correction decoding means for performing error correction decoding of the paging signal received via the respective trunk line. And selective combining means for selectively combining and transmitting a paging signal from another trunk line without error detection when an error is detected by the error correction decoding means.

[0010]

According to the first aspect of the invention, the peripheral station performs phase compensation on the call signal transmitted from the central station, and then performs error correction decoding for each signal of each trunk line and further performs error correction encoding. The selector selects one of the error-correction coded outputs and transmits it from the transmitter to the mobile communication transmission line.

If the error cannot be corrected as a result of the error correction decoding, the error correcting coded output of the paging signal that has been correctly decoded by the selective combining section can be selectively combined and transmitted from the transmitting section.

Further, the peripheral station performs the phase compensation on the calling signal transmitted from the central station without performing the error correction coding, and then performs the error correction decoding for each signal of each relay line. If an error is detected as a result of the error correction decoding, the selecting and combining section selects and combines a paging signal without error detection and transmits it from the transmitting section.

[0013] Thus, it is possible to suppress a decrease in communication quality due to an error occurring in the trunk line.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 4 is a block diagram showing the configuration of a peripheral station 3-i for explaining a first embodiment of the present invention. In FIG. 4, in the present embodiment, a phase compensating unit 5-1, an error correction decoding unit 9-1, an error correction code unit 10-1, a relay line 2-i- For 1, the phase compensator 5
-2, an error correction decoding unit 9-2, and an error correction encoding unit 10-2 are connected, and the configuration is such that phase compensation, error correction decoding, and further error correction encoding are performed for each relay line system. I have. Then, the error correcting code section 10-1 or 10-2 is selected by the selecting section 6.
One of the outputs is selected and transmitted by the transmission unit 7.

The operation of the peripheral station will be described. Trunk line 2
The paging signals received via -i-1 and -i-2 are phase-compensated by the phase compensators 5-1 and 5-2, respectively, and then sent to the error correction decoders 9-1 and 9-2. Input and error correction. further,
The error-corrected calling signal is sent to the error-correcting code section 10-1,
At 10-2, the signal is coded again into an error-correction coded signal similar to the paging signal received from the trunk line, and is input to the selector 6. The selection unit 6 selects a paging signal received from the trunk line 2-i-1 and a paging signal received via the trunk line 2-i-2, and modulates and amplifies the paging signal selected by the transmission unit 7. . The selector 6 is controlled so as to select another relay line when a line failure or a device failure occurs.

In this embodiment, the occurrence of a fault in the trunk line or a device failure can be detected by performing error correction decoding, and a normal trunk line side paging signal can be selected and transmitted.

(Second Embodiment) FIG. 5 is a block diagram showing the configuration of a peripheral station 3-i for explaining a second embodiment of the present invention. In the second embodiment, unlike the first embodiment, the peripheral station does not have an error correction coding section for performing error correction coding of the call signal, and the delay sections 11-1 and 11 which delay the phase-compensated call signal.
-2, the output of the delay units 11-1 and 11-2 is output in accordance with the error correction decoding results of the error correction decoding units 9-1 and 9-2. The feature is that the call signal of the side is selected and transmitted.

The operation of this embodiment will be described. Trunk line 2-i
-1 and paging signals received via 2-i-2 are phase-compensated by phase compensating units 5-1 and 5-2, respectively, and then corrected by error-correcting decoding units 9-1 and 9-2 and a delay unit. Input to 11-1 and 11-2. The error correction decoding units 9-1 and 9-2 perform error detection for each error correction codeword in the signal after the phase compensation, and notify the selection and synthesis unit 12 of the detection result. The error correction decoding unit 9-
In order to cause a delay in the error detection in 1 and 9-2, the delay units 11-1 and 11-2 adjust the input timing to the selection combining unit 12 after the error detection notification and the phase compensation. The selection / synthesis unit 12 divides the two paging signals input from the delay units 11-1 and 11-2 for each error correction codeword based on the error detection notification input from the error correction decoding units 9-1 and 9-2. To be synthesized. Further, the transmitting unit 7 modulates and amplifies the call signal selectively combined and transmits the modulated signal from the antenna.

FIG. 6 shows how the combining signal is combined in the selecting and combining section 12. FIG. 6A shows an error correction codeword in a call signal input from delay section 11-1. Also,
In FIG. 6A, the error detection result detected by the error correction decoding unit 9-1 is also shown below the corresponding codeword. Here, 〇 indicates a codeword for which no error was detected, and × indicates a codeword for which an error was detected. FIG. 6 (2) shows an error correction codeword in the call signal input from the delay unit 11-2, and the error detection result detected by the error correction code unit 9-2 is shown below the corresponding codeword. . FIG. 6 (3) shows a selective combining unit.
14 shows a call signal after selective combining output from 12. In the first code word, code word 1-1 input from delay section 11-1
No error is detected in the codeword 2-1 and an error is detected in the codeword 2-1 input from the delay unit 11-2, so that the codeword 1-1 is selected. In the same manner, codewords from which error of the codewords from the delay units 11-1 and 11-2 are not detected are selected and transmitted.

(Third Embodiment) FIG. 7 is a block diagram showing a configuration of a peripheral station 3-i for explaining a third embodiment of the present invention. In this embodiment, a phase compensator 5-1, an error correction decoder 9-1, and an error correction encoder 10 are provided for each of the trunk lines 2-i-1 and 2-i-2.
-1, a phase compensator 5-2, an error correction decoder 9-2, and an error correction encoder 10-2. The outputs of the error correction encoders 10-1 and 10-2 are supplied to the selection / synthesis unit 12, respectively. Is entered. The error detection output of the error correction decoding unit 9-1 is input to the selection / synthesis unit 12 via the delay unit 11-1, and similarly, the error detection output of the error correction decoding unit 9-2 is output to the delay unit 11-2. The data is input to the selection / combination unit 12 via

The operation of the peripheral station of this embodiment will be described. The paging signals received via the trunk lines 2-i-1 and 2-i-2 are phase-compensated by the phase compensating units 5-1 and 5-2, respectively, and then error-correction decoding units 9-1 and 9-2. Error corrected by -2. The error-corrected calling signal is again converted into an error-correction coded signal similar to the calling signal received from the trunk line by the error-correcting coding units 10-1 and 10-2, and is input to the selective combining unit 12. At this time, since a delay occurs in the error correction coding in the error correction coding units 10-1 and 10-2, the delay unit 11-1 and 11-2 selectively combine the correction result and the error correction coded signal. The timing of the input to the unit 12 is adjusted. In the selection synthesis unit 12,
Based on the correction results input by the error correction decoding units 9-1 and 9-2, two call signals input from the error correction code units 10-1 and 10-2 are combined for each error correction code word. further,
The calling signal modulated and amplified by the transmitting unit 7 is transmitted from an antenna.

The combining in the selective combining unit 12 is the same as that shown in FIG.

[0024]

As described above, according to the present invention, a call signal which has been error-correction-encoded and transmitted from a central station is error-correction-decoded at a peripheral station, thereby reducing errors generated in a trunk line. Is possible. In addition, the call signal that could not be corrected at the time of error correction is obtained by selectively combining signals received by other trunk lines,
It is possible to reduce that error.

Therefore, according to the present invention, it is possible to provide a high-quality radio paging system, and to use an error correction code for a mobile communication transmission line without applying error control unique to a trunk line. Has the advantage that it is not complicated.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a system of a wireless paging system.

FIG. 2 is a block diagram showing a configuration of a central station and peripheral stations of a conventional radio paging system.

FIG. 3 is a diagram illustrating a format of a call signal transmitted from a central office.

FIG. 4 is a block diagram showing a configuration of a peripheral station according to the first embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of a peripheral station according to a second embodiment of the present invention.

FIG. 6 is a diagram illustrating selective synthesis of a call signal according to a second embodiment.

FIG. 7 is a block diagram showing a configuration of a peripheral station according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Central station 2 Trunk line 3-1 to 3-n Peripheral station 4 Paging signal coding unit 5 Phase compensation unit 6 Selection unit 7 Transmission unit 8 Antenna 9 Error correction decoding unit 10 Error correction coding unit 11 Delay unit 12 Selection combining unit

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Nobuhiro Nishikawa 2-10-1 Toranomon, Minato-ku, Tokyo Inside NTT Mobile Communication Network Co., Ltd. (56) References JP-A-63-232632 (JP) JP-A-4-119030 (JP, A) JP-A-4-346529 (JP, A) JP-A-4-10723 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB (Name) H04B 7/26

Claims (2)

(57) [Claims] 1. A central office and,DistributedThe central office and 2
Multiple peripherals connected via the above trunk lines
Station and a radio call connected to this peripheral station via a radio line.
With outgoing receiverIn the radio paging system, the central office,Contains the address specifying the call receiver
In response to a paging signal, the peripheral station communicates with the paging receiver.
Error correction coding to be applied to the wireless line between
Through the trunk lineMeans for transmitting to each of the peripheral stations
Wherein each of the peripheral stations comprises: the paging signal received via the respective relay line.
Two or more error correction decoding means for performing error correction decoding of
Error correction code method corresponding to the same radio line as the central office
In the formulaTwo or more error correction coding means for performing error correction coding
And the output of this error correction coding meansError correction decoding
One of the ringing signals from the trunk line correctly decoded by the means
ToChoiceOutputMeans, This selected call signal is transmitted at the same frequency as other peripheral stations.
Transmitting means for transmitting to the call receiver; It is special that
Wireless paging system. (2)A central office, and the central office and 2
Multiple peripherals connected via the above trunk lines
Station and a radio call connected to this peripheral station via a radio line.
In a wireless paging system provided with an output receiver, The central office includes an address specifying the called receiver
In response to a paging signal, the peripheral station communicates with the paging receiver.
Error correction coding to be applied to the wireless line between
Means for transmitting to each of the peripheral stations via the relay line
With  Each of the peripheral stations,The paging signal received via the respective trunk line
Two or more error correction decoding means for performing error correction decoding of Each of the call signals decoded by the error correction decoding means is
Error correction code method corresponding to the same radio line as the central office
Two or more error-correcting codes for error-correcting coding by the formula Means
When, The output of the error correction encoding means is input, and Error correction
If the correct decoding means did not decode correctly, another error
Correct decoding by correction coding meansError-correction coded
Select one of the codewords that make up the paging signal in codeword units.
Means for selecting and synthesizing,This selectively synthesized call signal is transmitted to the same frequency as other peripheral stations.
Transmitting means for transmitting to the call receiver by a number Having
Characterized by Wireless calling system.