JPWO2016043054A1 - Wireless communication system, wireless device, and wireless communication method - Google Patents

Abstract

Provided is a wireless communication system that prevents establishment of communication with a mobile station using radio waves copied by a third party. In step S <b> 101, the base station 100 transmits “notification information” to the mobile station 200. In step S <b> 102, the mobile station 200 returns a “registration request” in which the scramble code C is set to the base station 100. The “notification information” and the “registration request” are scrambled with a predetermined scramble code A. In step S <b> 103, the base station 100 returns a “registration response” to the mobile station 200. In step S <b> 104, the mobile station 200 returns “response confirmation” to the base station 100. The “registration response” and the “registration response” are scrambled with the scramble code C set in the “registration request”. When the base station 100 receives the “response confirmation”, the communication between the base station 100 and the mobile station 200 is established.

Description

  The present invention relates to a wireless communication system, a wireless device, and a wireless communication method using, for example, an analog FM (frequency modulation) method, and more particularly, audio signals and data (hereinafter referred to as “communication data”) communicated wirelessly. ) Is scrambled to prevent communication data from being deciphered, and a wireless communication method and a wireless communication method.

For example, in an analog FM wireless communication system, in recent years, various scramble processes for providing concealment have been provided in order to prevent leakage of communication data. Such a conventional scrambling process for concealment will be described with reference to the drawings.
FIG. 5 shows the configuration of a conventional analog FM radio communication system (hereinafter referred to as “radio communication system”) 10. The wireless communication system 10 includes a base station 100 as a master station and a mobile station 200 such as a plurality of mobile terminals as slave stations, and the base station 100 and the mobile station 200 communicate with each other wirelessly.

  Processing on the transmission side and the reception side of the radio device 300 of the base station 100 and the mobile station 200 in the radio communication system 10 will be described with reference to FIG.

  First, processing on the transmission side of the wireless device 300 will be described with reference to FIG. When the DSP (Digital Signal Processing) 20 outputs the audio signal to the audio signal scramble processing unit 21, the audio signal scramble processing unit 21 scrambles the audio signal and outputs the scrambled audio signal to the FM modulation processing unit 24. To do. When the DSP 20 outputs data to the data scramble processing unit 22, the data scramble processing unit 22 scrambles the data, and outputs the scrambled data to an MSK (minimum-shift keying) modulation processing unit 23. When the scrambled data is input, the MSK modulation processing unit 23 performs minimum shift modulation that narrows the occupied band and outputs the result to the FM modulation processing unit 24. In this way, noise can be reduced by performing minimum shift keying to narrow the occupied band. When receiving the scrambled audio signal or data, the FM modulation processing unit 24 modulates the audio signal or data into a carrier wave (radio wave) and transmits it by the antenna 25.

  Next, processing on the receiving side of the wireless device 300 will be described with reference to FIG. When receiving the scrambled audio signal or data carrier wave received by the antenna 25, the FM demodulation processing unit 29 demodulates the carrier wave and outputs it to the audio signal descrambling processing unit 26 when the carrier wave is an audio signal. When the carrier wave is data, it is output to the MSK demodulation processing unit 28. When descrambling the scrambled audio signal, the audio signal descrambling processing unit 26 outputs the scrambled audio signal to the DSP 20. The MSK demodulation processing unit 28 outputs the scrambled data to the data descrambling processing unit 27 after performing minimum shift demodulation. When descrambling the scrambled data, the data descrambling processing unit 27 outputs the scrambled data to the DSP 20.

  Next, a procedure for delivering a scramble code between the base station 100 and the mobile station 200 of the wireless communication system 10 will be described with reference to FIG. 7 which is a sequence diagram until the base station 100 and the mobile station 200 establish communication. As shown in FIG. 7, first, in step S <b> 201, when base station 100 designates scramble code B, base station 100 transmits “broadcast information” in which scramble code A is set to mobile station 200. The “notification information” is scrambled with a predetermined scramble code A. Next, in step S <b> 202, when the mobile station 200 receives “notification information”, the mobile station 200 returns a “registration request” to the base station 100 when the mobile station 200 requests registration. The “registration request” is scrambled with a predetermined scramble code A. Next, in step S <b> 203, when receiving the “registration request”, the base station 100 returns a “registration response” notifying that the “registration request” is agreed to the mobile station 200. The “registration response” is scrambled with the scramble code B set in “notification information”. Next, in step S <b> 204, when receiving the “registration response”, the mobile station 200 returns a “response confirmation” notifying that the “registration response” has been confirmed to the base station 100. The “response confirmation” is scrambled with a scramble code B. When the base station 100 receives the “response confirmation”, communication between the base station 100 and the mobile station 200 is established. When transmitting subsequent communication data, the base station 100 is scrambled with the scramble code B, and when receiving communication data, the scramble code is received. The scramble is released by B.

  Conventionally, the base station 100, which is the host device in the wireless communication system 10, designates a scramble code, and the base station 100 and the mobile station 200 establish communication using the designated scramble code. For example, in the digital mobile radio system disclosed in Patent Document 1, the radio terminal station changes the scramble code of the radio terminal station according to the scramble code set in the “broadcast information” transmitted from the radio base station. Communication can be established with another radio base station that uses a scramble code for communication CH (channel) different from the radio system to which it originally belongs.

JP-A-2005-244575

Radio waves on the transmission side using the analog FM method according to the prior art can be duplicated by a measuring instrument 30 having a functional configuration shown in FIG. A procedure for measuring device 30 to replicate the radio wave of base station 100 will be described with reference to FIG. First, the modulation analyzer 32 demodulates the radio wave of the base station 100 received from the antenna 31 and outputs the demodulated audio signal to the reception side recorder 33. The receiving recorder 33 records the received audio signal as an audio signal, and duplicates the recorded audio signal to the transmitting recorder 34. The transmitter recorder 34 outputs the audio signal to the signal generator 35 when the recording of the recorded audio signal is completed. The signal generator 35 demodulates the input audio signal and transmits it from the antenna 31.
In this way, in the wireless communication system 10 using the analog FM system, when the base station 100 which is a higher-level device on the transmission side designates a scramble code, as in the digital system, a third party uses the measuring device 30 as a base station. The radio wave transmitted from 100 can be duplicated. As a result, since communication with the mobile station 200 can be established, there has been a problem that a radio wave jack of a wireless section by an unauthorized third party becomes possible.

  The present invention has been made in view of such a situation, and an object thereof is to provide a wireless communication system, a wireless device, and a wireless communication method that can solve the above-described problems.

The radio communication system of the present invention is a radio communication system having a master station and a slave station that perform radio communication, wherein the master station scrambles broadcast information with a predetermined first scramble code to the slave station. A registration request for transmitting information to the master station by scrambled a registration request in which a second scramble code is set with the first scramble code when receiving the broadcast information; A transmission means is provided, and subsequent communication data between the master station and the slave station is scrambled with the second scramble code.
The second scramble code of the wireless communication system uses the individual number of the slave station.
Further, the second scramble code of the wireless communication system uses a time from power-on of the slave station.
Further, the time from the power-on of the slave station in the wireless communication system is counted in a predetermined unit time.
The radio of the present invention is a radio provided in a slave station of a radio communication system, and receives broadcast information scrambled with a predetermined first scramble code from a master station. And registration request transmission means for transmitting a registration request in which a second scramble code is set by scrambled with the first scramble code when the broadcast information is received, and subsequent communication data with the master station Is scrambled with the second scramble code.
The radio communication method of the present invention is a radio communication method in a slave station of a radio communication system, and receives broadcast information scrambled with a predetermined first scramble code from a master station. And a registration request transmission step of transmitting a registration request with a second scramble code scrambled with the first scramble code when receiving the broadcast information, and subsequent communication data with the master station Is scrambled with the second scramble code.

  According to the present invention, even when a third party replicates and transmits a radio wave from a parent station, a wireless communication system that prevents establishment of communication with a slave station using the radio wave copied by the third party, A wireless device and a wireless communication method are provided.

It is a figure which shows the sequence until the base station and mobile station which concern on embodiment of this invention establish communication. It is a figure explaining the structure and scramble procedure of the air format which concerns on embodiment of this invention. It is a figure which shows the structure of PN (15,14) which concerns on embodiment of this invention. It is a flowchart of the scramble process and the descramble process which concern on embodiment of this invention. It is a figure which shows the structure of a radio | wireless communications system. It is a figure which shows the flow of a process of the transmission side and receiving side of a radio | wireless machine. It is a figure which shows the sequence until the base station and mobile station which concern on a prior art establish communication. It is a figure which shows the function structure of the measuring device which concerns on a prior art.

  The configuration of the radio communication system 10 in the embodiment of the present invention is the same as that of the radio communication system 10 shown in FIG. 5, and the flow of processing on the transmitting side and the receiving side of the base station 100 and the mobile station 200 is shown in FIG. The processing flow on the transmitting side and the receiving side of the base station 100 and the mobile station 200 shown in FIG. In the embodiment of the present invention, the procedure for delivering the scramble code of the wireless communication system 10 is different from the procedure for delivering the conventional scramble code. In the wireless communication system 10 as the embodiment shown in FIG. 5, the base station 100 is taken as an example of the master station and the mobile station 200 is taken as an example of the slave station. However, in the present invention, the master station is limited to the base station. is not. For example, the master station may be a radio device that is the master of a plurality of slave stations (having a special function that the plurality of slave stations does not have), and controls and manages the mobile station 200 (for example, restricts operation). ) A master station radio may be used. When the parent station performs operation restriction, the mobile station 200 may be configured to cancel the operation restriction for a predetermined time by performing communication illustrated in FIG. 1 with the parent station. In the wireless communication system of FIG. 5, a mobile station is taken as an example of a wireless terminal as a slave station. However, a wireless device that is not necessarily a mobile station but is used in a fixed manner may be used.

  First, with reference to FIG. 1, which is a sequence until the base station 100 and the mobile station 200 establish communication with respect to the procedure for passing the scramble code between the base station 100 and the mobile station 200 of the wireless communication system 10 according to the embodiment of the present invention. I will explain. As shown in FIG. 1, first, in step S <b> 101, the base station 100 transmits “broadcast information” to the mobile station 200. The “notification information” is scrambled with a predetermined scramble code A. Next, in step S102, when the mobile station 200 receives the “broadcast information”, the mobile station 200 requests registration, and when specifying the scramble code C, the mobile station 200 sends a “registration request” with the scramble code C set to the base station 100. Return to The “registration request” is scrambled with a predetermined scramble code A. Next, in step S <b> 103, when receiving the “registration request”, the base station 100 returns a “registration response” notifying that the “registration request” is agreed to the mobile station 200. The “registration response” is scrambled with the scramble code C set in the “registration request”. Next, in step S104, when receiving the “registration response”, the mobile station 200 returns a “response confirmation” notifying that the “registration response” has been confirmed to the base station 100. The “response confirmation” is scrambled with a scramble code C. When the base station 100 receives the “response confirmation”, the communication between the base station 100 and the mobile station 200 is established. When transmitting subsequent communication data, the base station 100 is scrambled by the scramble code C. When receiving the communication data, the scramble code C is received. To release the scramble.

  Next, the scramble process and the descramble process of the radio device 300 of the mobile station 200 will be described. The scramble processing is performed by the audio signal scramble processing unit 21 or the data scramble processing unit 22 (hereinafter referred to as “scramble processing unit”) shown in FIG. The descrambling process is performed by the audio signal descrambling processing unit 26 or the data descrambling processing unit 27 (hereinafter referred to as “descrambling processing unit”) shown in FIG.

First, a signal format (hereinafter referred to as “air format”) 40 of communication data transmitted and received in the radio section between the base station 100 and the mobile station 200 will be described with reference to FIG. As shown in FIG. 2 (1), the air format 40 includes a bit synchronization signal 41, a frame synchronization signal 42, and a message signal 43. The bit synchronization signal 41 and the frame synchronization signal 42 use the analog simple radio MSK format. In such an air format 40, for example, the modulation speed is 1200 bps, the mark frequency is 1200 Hz _Z “1”, and the space frequency is 1800 Hz _Z “0”.
The bit synchronization signal 41 is a 48-bit bit string composed of binary values 1 and 0 as shown in FIGS. 2 (1) and 2 (a) for informing the reception side of the bit detection timing of the transmitted signal.
The frame synchronization signal is a 31-bit M-sequence code (Maximum period sequence) consisting of binary values 1 and 0 as shown in FIGS. 2 (1) and 2 (b) for informing the reception side of the frame detection timing of the transmitted signal. : The maximum periodic sequence code). The M-sequence code is a pseudo-random sequence in a PN code (Pseudo Noise: pseudo-random code) that is an encryption key.
The message signal 43 is a bit string composed of a message message (64 bits) and a CRC code (16 bits) as shown in FIGS. The CRC code is a generator polynomial (1 + X ⁵ + X ¹² + X ¹⁶ ) that detects a signal error in a message message.

  The scramble procedure for the air format 40 will be described with reference to FIG. First, as shown in FIG. 2 (2) (A), a message signal 43 composed of a message telegram and a CRC code is taken out from the air format 40. Next, the message signal 43 is scrambled by the scramble code C as shown in FIG. Next, the scrambled message signal is stored in the air format 40 as shown in FIGS. The descrambling procedure is the same as the scrambling procedure of FIG. 2 except that the message signal 43 is changed to “cancel scramble by scramble code C” in FIG.

Next, the scramble code A and the scramble code C shown in FIG. 1 will be described.
The scramble code A can be an arbitrary code determined in advance by the base station 100 and the mobile station 200. For example, a part of the serial number of the base station 100 or the mobile station 200 can be used as the scramble code A.
The scramble code C is a scramble code designated by the mobile station 200, and has a different value for each mobile station 200. Also, the same mobile station 200 has a different value every time a “registration request” is transmitted. For this reason, the initial value of the scramble code C is determined using the individual number of the mobile station 100 and the time since the power of the mobile station 100 was turned on.

When the scramble code C generated from the individual number of the mobile station 100 and the time since the power of the mobile station 100 is turned on is a bit string of 15 bits, for example, the individual number is 3 bits and the count time. Is assigned to be 12 bits. In such a case, 8 (= 2 ³ ) mobile stations 200 can be identified by 3 bits of the individual number. Further, counting is performed with 12 bits (4096 = 2 ¹² ) of the count time, and when one count time is 5 msec, one cycle is 4095 × 5 msec = 20475 msec (20.475 sec).

In order to scramble the message signal 43, the bit string of the message signal 43 is multiplied by PN (15, 14), which is the PN code shown in FIG. Randomize.
PN (15, 14) is a bit string of 15 bits of _{S 14} from _{S 0} is provided as shown in FIG. The PN (15, 14) sequentially shifted to the right bit by bit, the value of _{S 0} bits and _{S 1} bit ExOR (exclusive OR) the value of _{S 14} bits, one after another by repeatedly performing this A pseudo-random number is generated. That is, when the scramble code C is set as the initial value of the PN code, a pseudo random number of the scramble code C is generated.

  Next, the scramble procedure of the message signal 43 by the PN (15, 14) executed by the scramble processing unit will be described in the order of steps of the flowchart shown in FIG.

(Step S11)
First, the scramble processing unit creates a scramble code C including an individual number and a count time. The current count time is set as the count time. The scramble code C is assigned a pattern number, and the pattern number is associated with the message signal 43 and stored in a storage unit (not shown) such as an auxiliary storage device.

(Step S12)
Next, the scramble processing unit sets the scramble code C created in step S11 to the register initial value of PN (15, 14).

(Step S13)
Next, the scramble processing unit sequentially outputs S ₀ S ₁ S ₂ S ₃ ... Of the bit string of the PN ( _{15, 14} ) register.

(Step S14)
Next, when the scramble processing unit inputs the message signal 43, the bit of S ₀ S ₁ S ₂ S ₃ ... Of the bit string of PN ( _{15, 14} ) output in step S13 from the head of the message signal 43. When each ExOR (exclusive OR) operation is performed and the scrambled message signal 43 is output, the scramble processing is terminated.

  Next, the descrambling procedure of the message signal 43 by the PN (15, 14) executed by the descrambling processing unit will be described in the order of steps in the flowchart shown in FIG.

(Step S21)
First, the descrambling processing unit extracts the scramble code C having the pattern number corresponding to the message signal 43 from the storage unit 20a.

(Step S22)
Next, the descrambling processing unit sets the scramble code C extracted in step S21 in the register of PN (15, 14).

(Step S23)
Next, the descrambling processing unit sequentially outputs S ₀ S ₁ S ₂ S ₃ ... Of the bit string of PN ( _{15, 14} ).

(Step S24)
Next, when the descramble processing unit inputs the scrambled message signal 43, S ₀ S ₁ S ₂ S ₃ ... Of the bit string of PN ( _{15, 14} ) output in step S23 from the head of the message signal 43. ... ExOR (exclusive OR) operation for each bit is performed, and when descrambling message signal 43 is output, descrambling processing ends.

  As described above, in the wireless communication system 10, the base station 100, which is the host device on the transmission side, does not specify the scramble code, but the mobile station 200 specifies the scramble code. Even when the radio wave transmitted from is duplicated, the scramble code is not duplicated. Therefore, since communication with the mobile station 200 cannot be established, it is possible to prevent radio jacks in the wireless section by unauthorized third parties.

  In the embodiment, the scramble code C including the individual number of the mobile station 100 and the count time after the mobile station 100 is turned on has been described. It is possible to use the other data having a different value for each transmission as the scramble code C. Further, although the scramble code C is a 15-bit bit string, 3 bits are assigned to the individual number and 12 bits are assigned to the count time, the present invention is not limited to this. For example, it is possible to allocate 5 bits to the individual number and 10 bits to the count time.

  The wireless communication system, the wireless device, and the wireless communication method of the present invention can move using a radio wave copied by a third party even when the third party replicates and transmits a radio wave from a base station. It is possible to prevent establishment of communication with a station.

  As mentioned above, although this invention was demonstrated by specific embodiment, it cannot be overemphasized that the said embodiment is an illustration of this invention and is not limited to this embodiment.

The characteristics of the above embodiment are summarized as follows.
(1) The radio communication system of the present invention is a radio communication system having a master station and a slave station that perform radio communication, wherein the master station scrambles the broadcast information with a predetermined first scramble code. Broadcast information transmission means for transmitting to the slave station, and when the broadcast station receives the broadcast information, the slave station scrambles a registration request in which a second scramble code is set with the first scramble code and transmits the registration request to the master station Registration request transmission means for scrambles subsequent communication data between the master station and the slave station with the second scramble code.
(2) The wireless communication system according to (1) is characterized in that the second scramble code uses an individual number of the slave station.
(3) The wireless communication system according to (1) or (2) is characterized in that the second scramble code uses time from power-on of the slave station.
(4) The wireless communication system according to (3) is characterized in that the time from power-on of the slave station is counted in a predetermined unit time.
(5) The wireless communication system according to any one of (1) to (4) is characterized in that the scramble is applied to an air format message signal.
(6) The wireless communication system according to any one of (1) to (5) is characterized in that communication data scrambled with the first scramble code is descrambled with the first scramble code. Yes.
(7) The wireless communication system according to any one of (1) to (5) is characterized in that communication data scrambled with the second scramble code is descrambled with the second scramble code. Yes.
(8) A radio apparatus according to the present invention is a radio apparatus provided in a slave station of a radio communication system, and receives broadcast information scrambled with a predetermined first scramble code from a master station. Receiving means and registration request transmitting means for transmitting a registration request in which a second scramble code is set by being scrambled with the first scramble code when the broadcast information is received, and subsequent communication with the master station The data is scrambled with the second scramble code.
(9) A radio communication method according to the present invention is a radio communication method in a slave station of a radio communication system, and receives broadcast information scrambled with a predetermined first scramble code from a master station. A receiving step, and a registration request transmitting step of transmitting a registration request in which a second scramble code is set by scrambled with the first scramble code when the broadcast information is received, and thereafter communicating with the master station The data is scrambled with the second scramble code.

  The present invention is suitable for a wireless communication system, a wireless device, and a wireless communication method, but is not limited to a wireless communication system, a wireless device, and a wireless communication method, and a communication system, a communication device, and a communication that perform scrambling The method is generally applicable.

10 .... Radio communication system 20 .... DSP
20a: Storage unit 21: Audio signal scramble processing unit 22: Data scramble processing unit 23: MSK modulation processing unit 24: FM Modulation processing unit 25... Antenna 26... Audio signal descrambling processing unit 27... Data descrambling processing unit 28. ··· FM demodulation processing unit 30 ··· Measuring instrument 31 ··· Antenna 32 · · · Modulation analyzer 33 · · · Receiver recorder 34 ···・ Sending recorder 35 ・ ・ ・ ・ ・ ・ Signal generator 40 ・ ・ ・ ・ ・ ・ Air format 41 ・ ・ ・ ・ ・ ・ Bit synchronization signal 42 ・ ・ ・ ・ ・ ・ Frame synchronization signal 43 ・ ・ ・ ・ ・ ・ Message signal 43a: Message telegram 43b: CRC code 100: Base station (master station)
200: Mobile station (slave station)
300 ... Radio

Claims (8)

In a wireless communication system having a master station and a slave station that perform wireless communication,
The master station is
Broadcast information transmitting means for scrambled broadcast information with a predetermined first scramble code and transmitting to the slave station,
The slave station is
When receiving the broadcast information, a registration request transmission unit is provided that scrambles a registration request in which a second scramble code is set with the first scramble code and transmits the scramble code to the master station.
A wireless communication system, wherein subsequent communication data between the master station and the slave station is scrambled with the second scramble code.   The wireless communication system according to claim 1, wherein the second scramble code uses an individual number of the slave station.   The wireless communication system according to claim 1, wherein the second scramble code uses a time from power-on of the slave station.   The wireless communication system according to claim 2, wherein the second scramble code uses a time from power-on of the slave station.   4. The wireless communication system according to claim 3, wherein the time from power-on of the slave station is counted in a predetermined unit time.   5. The wireless communication system according to claim 4, wherein a time from power-on of the slave station is counted in a predetermined unit time. A wireless device provided in a slave station of a wireless communication system,
Broadcast information receiving means for receiving broadcast information scrambled with a predetermined first scramble code from a master station;
Registration request transmission means for transmitting a registration request in which a second scramble code is set and receiving a scramble with the first scramble code when the broadcast information is received;
A radio device characterized in that subsequent communication data with the master station is scrambled with the second scramble code. A wireless communication method in a slave station of a wireless communication system,
A broadcast information receiving step of receiving broadcast information scrambled with a predetermined first scramble code from a master station;
A registration request transmitting step of transmitting a registration request in which a second scramble code is set when the broadcast information is received and scrambled with the first scramble code;
A wireless communication method characterized in that subsequent communication data with the master station is scrambled with the second scramble code.

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