JPS6115429A - Radio selective call communication system - Google Patents

Abstract

PURPOSE:To control the information desired not to be known by an unpermitted receiver especially at a base station by adding a scramble circuit and its control section to the base station, and a descramble circuit to a receiver. CONSTITUTION:A signal transmitted from a telephone set 1 is converted into a code by a control section 3 through an exchange 2, modulated by a modulation section 4, and transmitted via a transmission section 5 and an antenna 6. The control section 3 applies scrambling to its code. The signal transmitted from the base station is demodulated by a demodulation section 9 via a reception section 8 from an antenna 7, one is inputted to a decoder 12 via a gate 11, and the other is inputted to the decoder 12 via the gate 11 from the descramble circuit 10. The descramble circuit 10 acts like restoring the scrambled code by the control section 3 of the base station. When a signal C is inputted to the decoder 12, it is compared with a call number stored in the ROM13 in advance and when they are coincident, a speaker 17 is energized and an information code succeeding to the call number is displayed on a display device 14.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a nine-individual radio selective calling communication system.

In particular, it relates to a communication system that can service the same information to all receivers with the same group number.

[Prior art and problems to be solved by the invention] Conventionally,
This type of communication system has the disadvantage that the code format is formalized to some extent, and that even other unauthorized receivers can enjoy the information service.

The present invention attempts to eliminate the above-mentioned drawbacks and provides a wireless selective calling communication system in which only a specific receiver can enjoy a call service.

[Means for solving problems]

According to the present invention, it is possible to obtain a radio selective call communication system using a base station having means for scrambling information codes and a receiver having means for descrambling the scrambled information codes.

〔Example〕

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

FIG. 2 is an example format of a signal transmitted from a base station to a receiver according to an embodiment of the invention. In the figure, P is a bit synchronization signal, F is a frame synchronization signal, N is a calling number common to the group, X is a control signal for whether or not to scramble, ~IN is an information signal, and E is the end of one group. This is a signal indicating.

FIGS. 1(a) and 1(b) are block diagrams showing the configurations of a base station (FIG. 1(a)) and a receiver (FIG. 1(b)) according to the present invention, respectively. In FIG. 1 (,), a signal sent from a telephone 1 is first converted into a code by a control unit 3 through an exchange 2, modulated by a modulation unit 4, and then sent to a transmission unit 5 and an antenna 6. It will be sent after The control unit 3 has a function of scrambling the code.

In Figure 1(b), the signal sent from the base station is
The signal is demodulated by the demodulator 9 through the antenna 7, the receiver 8, and the other is inputted to the decoder 12 via the receiver 11, and the other is input to the decoder 12 from the descrambling circuit 10 via the gate 11. In addition.

The descrambling circuit 10 has a function of restoring the code scrambled by the control unit 3 of the base station to the original code. Also, Kate 11.

It has a function that allows input A or B to be selected by inputting a signal from the decoder 12. When the signal C is input, the decoder 12 compares it with the calling number previously stored in the ROM i 3, and if they match, it operates the tone generating circuit 16 to emit a sound from the speaker 17, and the information code following the calling number is output to the decoder 12. is displayed on DisGray 14. Note that in the signal input to the decoder 12, when the signal X in FIG.
outputs the input signal B, and when the signal
is output. 15 is a crystal resonator.

Next, the operation of the control section 3 on the base station side in FIG. 1(a) will be explained in detail with reference to FIG. 3, which is a block diagram thereof. When calling an individual receiver from a regular telephone subscriber, the individual calling number assigned to the receiver is dialed from the telephone 1 of the telephone subscriber. Dial signal is from exchange 2
is input to trunk 3-2 via register 3-3.
is input to. The operator manually inputs the call number into register 3-4 by operating manual 3-4.
You can also enter 3. Further, the manual switch 3-4 can be used to stop the signal from the exchange 2 to the trunk 3-2, and the 2-signal generator 3-1 can interrupt the information service as shown in FIG.

When the register 3-3 receives a predetermined number of calls (for example, 4 calls), the register 3-3 transfers the BCD to the storage circuit 3-6.
(Binary Coded Decimal) Transfer all call numbers converted to numbers. The storage circuit 3-6 stores the calling number until a read signal from the timing circuit 3-5 arrives. Timing circuit 3-5 is memory circuit 3
When the number is input to -6, the synchronization signal generator 3-11 is activated to generate the signal P (bit synchronization code) shown in FIG.

A signal F (frame synchronization code) is generated, and these signals are sent to the modulation section 4 via the AND/GO signal 3-14. Further, following the completion of sending out the P code and the F code, the timing circuit 3-5 sends out a read signal to the storage circuit 3-6, and at the same time, the timing circuit 3-5 sends out a readout signal to the code converter 3-7° encoding circuit 3-8.
．． Scramble circuit 3-9. and andgoo) 3-1
Operate 2.

Now, if the calling number is stored in the memory circuit 3-6, the calling number is sent to the code converter 3-7 in number units in the storage order according to the readout signal from the timing circuit 3-5.
6 is transferred until it becomes empty. Code converter 3-7 is BC
Convert the D number to a 21-bit pure binary code.

The encoding circuit 3-8 adds a 10-bit/return check bit to the 21-bit number code, and converts the calling number consisting of the 2-cycle code BCH (31, 21) into the case 3.
-10 and the scramble circuit 3-9. Also,
The signal scrambled by the scramble circuit 3-9 is sent to the gate 3-10. When transmitting a scramble code, the manual switch 3-4 interrupts the scramble control signal from the signal generator 3-1 to the signal X shown in FIG. A scramble control signal is sent to the gate 3-10 so that input A is closed and input B is output.

At the same time as the E signal (1 group node end code) shown in FIG. will open.

Signal C output from gate 3-10 is goo) 3-12
It is sent to the modulator 4 via 3-13 and 3-14.

The timing circuit 3-5 starts a built-in timer when the E signal generator 3-15 finishes sending the signal. If a new number storage signal is received from the memory circuit 3-6 within this timer setting time, the above series of operations is repeated.

At this time, the storage signal from the second time (Tsuma!I 11th E
When the code is the next storage signal generated, the synchronizing signal generating section 3-11 staggers the operation according to the output signal of the timing circuit 3-5 until the above-mentioned timer times out. On the other hand, when the above-mentioned timer times out, the timing circuit 3-5 does not generate an output signal unless a new number is input to the storage circuit 3-6. Through the series of operations described above, a signal train as shown in FIG. 2 is sent out.

Next, the operation of the decoder 12 on the receiving side in FIG. 1(b) will be explained using FIG. 4, which is a block diagram thereof.

The decoder 12 is a 1-chip CPU, and the input port 12
-12 inputs the signal encoded by r-)11,
The output is sent to data bus 12-9. Output port 12-1
3 receives an instruction from the data bus 12-9 and sends out a signal instructing reading of the call code written in the ROM 13. The input capo 12-14 receives the call code read out according to the above instruction and sends it to the data bus 12-9. Output port 12-10 receives an instruction from data bus 12-9 and outputs a signal for operating tone generating circuit 16. A sequence of operating instructions as a decoder is written in the program memory 12-3, and the program counter 12-3
The contents of the address corresponding to 2 are sent to the control section 12-4. Based on this content, the control unit 12-4 decodes the code to be executed and controls each block that is to execute this instruction.

The logic operation unit 12-5 is a memory that stores operation results via a data bus.

Exchange data between input and output ports. memory 1
2-7 is an input capo) 12-12 holds the signal sent via the data path, and its contents are stored for a predetermined time by the control of a timer built in this data memory 12-7. Only display control driver 12-8
is displayed on the display 14 via. Output port 1
2-11 receives an instruction from the data bus 12-9 and outputs a signal for operating the control of the gate 11.

Here, the operation of the embodiment of the receiver will be explained using the flowchart of FIG. First, in step 20, a signal is received, and in steps 21, 22, and 23, when a bit synchronization code P, frame synchronization code F, and call number N are detected, respectively, the speaker 17 generates a tone. Further, in step 25, it is determined whether the signal is a scrambled signal, and if it is a scrambled signal, descrambling processing is performed and information processing is performed in steps 26 and 27, and if it is not a scrambled signal, information processing is performed as is. The processed signal is displayed on a display such as an LCD, and the above operation continues until there is an E symbol indicating the end of the group.

Next, simple examples of the scramble circuit 3-9 in FIG. 3 and the descramble circuit 10 in FIG. 1 are shown in FIGS. 6 and 7. In FIG.

31 is a 4-bit shift register, 33it, D
It's Frisozofrozzo. Similarly, in Figure 7, 3
5 is a 4-bit shift register, and 37 is a D flip-flop.

Since these are all basic circuits, their operations will be omitted, but a timing chart of input and output signals of each of these parts (indicated by alphabets in the figure) is shown in FIG. It goes without saying that if the AND darts 32 and 36 in FIGS. 6 and 7 are replaced with a ROM or the like, the encryption will be even better.

〔Effect of the invention〕

As described above, according to the second aspect of the present invention, by adding a scrambling circuit and its control unit to the base station and a descrambling circuit to the receiver, the base station controls information that it does not particularly want unauthorized receivers to know. I can do it. Although information services common to a group have been described here, it is also possible to scramble and encrypt an individual call number and the message that follows it.

[Brief explanation of the drawing]

Figures 10 and (b) are block diagrams showing the configurations of the base station and receiver in this embodiment, Figure 2 is a diagram showing an example of the format of the received signal, and Figure 3 is the same as Figure 1.
), FIG. 4 is a block diagram showing the configuration of the decoder 12 in FIG. 1(b), FIG. 5 is a flowchart showing the operation of the receiver of this embodiment, and FIG. 7 and 7 respectively show an embodiment of the scramble circuit 3-9 in FIG. 3 and the desk simple circuit 10 in FIG. FIG. 3 is a diagram showing a timing chart of input/output signals. In the figure, 1 is a telephone, 2 is an exchange, and 3 is a control unit. 4 is a modulation section, 5 is a transmission section, 8 is a reception section, 9 is a demodulation section, 1
0 is a descrambling circuit, 11 is a dirt. 12 is a decoder, t is a ROM, 14 is a display 15 is a crystal oscillator, and 16 is a tone generation circuit. Agent (7127) Patent attorney Yosuke Goto Figure 1

Claims (1)

[Claims] 1. The base station transmits an individual calling code, a message code following this code, and a calling code common to one group and a plurality of information codes following this code, and the receiver operates the receiving device in synchronization with the code. In the selective call communication system, the information code is displayed as an information signal if the call code matches a predetermined built-in call code, the base station has means for scrambling the information code, and the base station has means for scrambling the information code, A wireless selective call communication system, characterized in that the receiver has means for descrambling the scrambled information.