JP2001292476A - Wireless communication method and its wireless communication unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel wireless communication method and a novel wireless communication unit that can realize quick encryption communication with a communication opposite party. SOLUTION: The wireless communication unit is provided with an analog modulation section that applies analog modulation to a voice signal, a digital modulation section that applies digital modulation to the voice signal that is subjected to coding processing, a frequency hopping modulation section that selects a frequency of a primary modulation signal from the digital or analog modulation section in prescribed timing and provides an output, a transmission reception section that transmits/receives a secondary modulation signal from the frequency hopping modulation section via an antenna section, and a coding processing section that applies the coding processing to the voice signal synchronously with the frequency switching timing of the frequency hopping modulation section.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio communication system and a radio communication apparatus for realizing prompt confidential communication with a communication partner.

[0002]

2. Description of the Related Art In general, a portable wireless device or the like adopting a digital system has a high level of confidentiality of communication contents and is capable of taking advanced security measures based on encryption technology.
For example, Japanese Unexamined Patent Publication No. Hei 5-219049 discloses that a pseudo-random signal is generated based on randomly generated key data, and the pseudo-random signal is combined with a digitized audio signal to generate a voice with a communication partner. A wireless communication device configured to provide confidentiality to a signal is described. The encryption of such an audio signal requires more time to decrypt the more complicated the content, and it is possible to prevent eavesdropping by a third party. In such a case, real-time performance with a communication partner is required, so that confidentiality can be maintained, but it is desirable that the decryption be performed promptly.

On the other hand, as a communication system excellent in confidentiality and interference resistance, there is a frequency hopping communication system in which a carrier frequency is switched at regular time intervals. If such a frequency hopping communication method is used as a secondary modulation method for a portable wireless device or the like, it is possible to impart a high degree of confidentiality to the contents of a call without applying complicated encryption technology, and to realize real-time performance with a communication partner. Can also be secured. Also,
When applied to a wireless communication device or the like that switches between analog communication and digital communication, the communication content can be made confidential by frequency hopping regardless of which communication is performed. As a wireless communication device for switching between analog communication and digital communication, for example, Japanese Patent Application Laid-Open No. 6-28
There is a dual mode wireless communication device as described in Japanese Patent No. 4464.

[0004]

However, usually, the frequency hopping timing in the frequency hopping method is different from the frame synchronization timing in the audio data encoding process and the encryption timing in the encryption process. When a frequency hopping method is applied as a secondary modulation method for a portable wireless device of a wireless communication method, or a frequency hopping method is applied as a secondary modulation method for a portable wireless device that switches between analog communication and digital communication as in the latter case. In this case, the receiving terminal performs a synchronization process for frequency hopping, and then performs a synchronization process for inverse encryption of audio data and a synchronization process for audio data decryption. Therefore, for example, when encryption technology is applied to audio data, it is necessary for the receiving terminal to further perform encryption synchronization processing for decryption,
Although the confidentiality of the communication contents is improved, there is a problem that a long processing time is required to reproduce the audio signal transmitted from the transmission side. Note that the time required for the synchronization processing required to reproduce such a received signal is not only at the time of starting communication with a communication partner, but also at the time of switching from analog communication to digital communication or from normal digital communication to encrypted communication. This is also a problem that occurs when switching.

FIG. 10 shows a processing procedure for switching from analog communication to digital communication in an analog / digital shared radio communication device (receiving side) using such a frequency hopping method as a secondary modulation method. It is a flowchart figure. As shown in FIG. 10, in the receiving terminal, a series of processes such as a UW detection process by digital demodulation, an encryption synchronization establishment process, and a voice synchronization establishment process must be performed before switching from analog communication to digital communication. Processing time (t1) obtained by adding such processing time
+ T2 + t3 + t4) is a communication unavailable time during which communication with the communication partner cannot be performed. In voice communication, such a communication unavailable time is a very inconvenient time for the user, and since real-time performance with the communication partner is required as described above, such switching from analog communication to digital communication, etc. Is desirably performed more quickly.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has as its object to provide a new wireless communication system and a wireless communication apparatus for realizing prompt confidential communication with a communication partner. And

More specifically, for example, in a case where a wireless communication device such as a cordless telephone in a home or a company to which the analog communication system is conventionally applied has a confidentiality, the confidentiality can be improved, It is an object of the present invention to provide a new wireless communication method and a new wireless communication device capable of shortening a communication unavailable period accompanying switching from communication to digital communication.

[0008]

According to a first aspect of the present invention, there is provided a radio communication method wherein at least encoded audio data is digitally modulated, and the digitally modulated audio data is secondarily modulated by a frequency hopping modulator. In the wireless communication method of performing transmission and reception with a communication partner, the audio data is transmitted by synchronizing the frame synchronization timing of the encoding process with the frequency switching timing of the frequency hopping modulation unit, and the frequency added to the audio data. The audio data received by the synchronization signal common to the hopping period is decoded.

According to a second aspect of the present invention, there is provided a wireless communication apparatus comprising: an analog modulator for analogly modulating an audio signal; a digital modulator for digitally modulating an encoded audio signal; A frequency hopping modulator for switching and outputting the frequency of the primary modulation signal from the unit at a predetermined timing; a transmitting and receiving unit for transmitting and receiving a secondary modulation signal from the frequency hopping modulator via an antenna unit; And a coding section for performing the above-described coding processing of the audio signal in synchronization with the frequency switching timing of the section.

A wireless communication apparatus according to a third aspect of the present invention is provided with an encryption unit for performing an encryption process on the encoded data from the encoding unit, and performs the encryption process of the encryption unit with the frequency hopping modulation. This is performed in synchronization with the frequency switching timing of the section.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram showing a wireless communication apparatus according to an embodiment of the present invention, and it is assumed that a communication partner also has the same configuration. Further, the wireless communication apparatus according to the present embodiment includes an analog communication system for transmitting and receiving to and from a communication partner using an analog-modulated audio signal, and a digital communication system for transmitting and receiving to and from a communication partner using a digitally-modulated audio signal, One of these communication systems is selected to communicate with a communication partner.

In FIG. 1, reference numeral 1 denotes an input switching unit for outputting an audio signal input from an input means such as a microphone to any one of communication systems described later, and 2 denotes an audio signal output from the input switching unit 1 to A / A. D converter into digital audio data, further the audio data coding process, the frequency hopping period T _FH audio frame period T as described below
An audio encoding processing unit for forming an audio frame to be _F ;
Is a digital modulation unit that performs digital modulation processing on the audio frame for each frequency hopping cycle output from the audio encoding processing unit 2, 4 is an analog modulation unit that performs analog modulation processing on the audio signal output from the input switching unit 1, Reference numeral 5 denotes a transmission-side switching unit to which a so-called primary modulation signal from the digital modulation unit 3 or the analog modulation unit 4 is input according to selection of an analog communication system or a digital communication system, and 6 denotes an output from the transmission-side switching unit 5. A frequency hopping modulation unit (hereinafter referred to as an FH modulation unit) that receives a primary modulation signal, switches the frequency of the primary modulation signal at a predetermined timing based on a reference clock signal from a reference clock 7, and outputs the switching signal. A so-called secondary modulation signal that has been frequency-hopped by the modulator 6 is input, and the secondary modulation signal is amplified to a predetermined transmission level and transmitted. A transmission unit 9 for outputting a signal, a transmission / reception switching unit such as a circulator for switching between a transmission state and a reception state, and 10 transmitting a transmission signal from the transmission unit 8 output through the transmission / reception switching unit 9 to a communication partner, An antenna unit that receives a transmission signal from a communication partner.

A receiving unit 11 amplifies a transmission signal of a communication partner received by the antenna unit 10 to a predetermined reception level, and a reception unit 12 receives a reception signal output from the reception unit 11 and inputs the reception signal to the reception signal. On the other hand, a frequency hopping demodulator (hereinafter referred to as F) for performing frequency hopping synchronization processing or demodulation processing based on a reference clock signal from the reference clock 7.
This is called an H demodulation unit. ) And 13 are receiving-side switching units for outputting the original analog modulated signal or the original digital modulated signal output from the FH demodulation unit 12 to the corresponding communication system in accordance with the selection of the analog communication system or the digital communication system, respectively. Reference numeral 15 denotes an analog demodulation unit to which an original analog modulation signal output from the reception side switching unit 13 is input and performs analog demodulation processing;
Is a digital demodulation unit that receives the original digital modulation signal output from the receiving side switching unit 13 and performs digital demodulation processing. 16 is the original audio frame that is output from the digital demodulation unit 15 and is input. FH demodulation unit 1
The audio decoding processing unit 17 that decodes based on the frequency hopping timing signal from 2 and reproduces the original analog audio signal is switched according to the selection of the analog communication system or the digital communication system. Analog audio signal reproduced by unit 16 and analog demodulation unit 1
And an output switching unit for outputting an analog audio signal reproduced by the external device 4 to the outside via audio output means such as a speaker.

Reference numeral 18 denotes a storage unit in which a predetermined communication protocol for application of the present invention is stored, and a communication operation between wireless communication devices based on such a communication protocol and an input from an operation unit. A communication control unit 19 for controlling a switching operation of an analog communication system or a digital communication system according to an operation, and a user performs a call operation or a call reception operation to a communication partner, and selects an analog communication system or a digital communication system. And an operation unit including dial keys and the like for instructing switching. In the wireless communication apparatus according to the present embodiment, selection of an analog communication system or a digital communication system can be performed by the user through an input operation from the operation unit 19 before the start of a call. It is assumed that the user can switch from the currently used communication system to another communication system by performing an input operation using the operation unit 19 even during the operation. For example, during a call with a communication partner using an analog communication system, the user can switch to a digital communication system by performing a switching operation using the operation unit 19, and the user can talk with the communication partner in a highly confidential state. It is possible to do.

Next, the operation will be described. First, a case where analog communication is performed will be briefly described. When the user performs an input operation to select analog communication using the operation unit 19, an operation signal from the operation unit 19 is input to the communication control unit 18, and the communication control unit 18 thereafter performs analog communication based on a preset communication protocol. A transmission system (input switching unit 1 → analog modulation unit 4 → transmission side switching unit 5 → FH modulation unit 6 → transmission unit 8 → transmission / reception switching unit 9 → antenna unit 10) and reception system (antenna unit 10 → transmission / reception switching) Unit 9 → Receiver 1
1 → FH demodulation unit 12 → reception-side switching unit 13 → analog demodulation unit 14 → output switching unit 17).

When the call operation is started, the voice signal from the input means input to the input switching section 1 is converted into an analog signal by the analog modulation section 4.
After being analog-modulated by FH, the signal is input to the FH modulation unit 6 via the transmission-side switching unit 5 and subjected to frequency hopping modulation by the FH modulation unit 6, and then transmitted from the transmission unit 8 to the transmission / reception switching unit 9 and the antenna unit 10. Transmitted to the communication partner via the Internet. The transmission signal from the communication partner received by the antenna unit 10 is input to the reception unit 11 via the transmission / reception switching unit 9, and is converted to a fixed frequency by the FH demodulation unit 12. The signal is input to the analog demodulation unit 14 via the unit 13, subjected to analog demodulation processing by the analog demodulation unit 14, and output from the audio output unit to the outside via the output switching unit 17.

Next, the case of performing digital communication will be described in detail. When the user performs an input operation for selecting digital communication using the operation unit 19, an operation signal from the operation unit 19 is input to the communication control unit 18, and the communication control unit 18 thereafter performs digital communication based on a preset communication protocol. system,
That is, the transmission system (input switching unit 1 → voice encoding processing unit 2 →
Digital modulation unit 3 → transmission side switching unit 5 → FH modulation unit 6 → transmission unit 8 → transmission / reception switching unit 9 → antenna unit 10) and reception system (antenna unit 10 → transmission / reception switching unit 9 → receiving unit 11 → FH)
Demodulation unit 12 → Reception side switching unit 13 → Digital demodulation unit 15 →
The communication operation by the audio decoding processing unit 16 → the output switching unit 17) is controlled.

For example, when the operation shifts from a calling operation or an incoming call operation to a call start operation, an audio signal from the input means input to the input switching unit 1 is first converted into digital audio data by the audio encoding processing unit 2. , And an audio frame for each predetermined unit is formed based on the audio data.
Here, the frequency hopping timing signal from the FH modulation section 6 is input to the voice coding processing section 2, and the voice coding processing section 2 outputs the frequency hopping period T _FH of the voice frame synchronized with the frequency hopping cycle T _FH of the FH modulation section 6. Perform formation. That is, F
An audio frame is formed with the frequency hopping period _TFH of the H modulation unit 6 as the audio frame period _TF . In addition,
A preamble signal (hereinafter, referred to as preamble) for reproducing a clock required for digital decoding as described later and a unique word (hereinafter, referred to as UW) for detecting the bit order of the audio frame are added to the audio frame. It is output from the speech encoding processing unit 2 in the state in which it is performed.

The audio frame output from the audio encoding processing unit 2 is digitally modulated by the digital modulation unit 3 and a signal subjected to the primary modulation processing (hereinafter, referred to as a primary modulation signal). Is output to the FH modulation section 6 via the transmission-side switching section 5. The FH modulator 6 performs a so-called frequency hopping modulation process, and the frequency of the primary modulation signal output from the digital modulator 3 is changed to the frequency hopping period T.
_Can be switched with _FH . The signal subjected to the secondary modulation processing by the FH modulation unit 6 (hereinafter, referred to as a secondary modulation signal) is output to the transmission unit 8, amplified to a predetermined level by the transmission unit 8, and switched as a transmission signal between transmission and reception. It is transmitted to a communication partner via the unit 9 and the antenna unit 10.

FIG. 2 shows the data structure of the transmission signal transmitted via the digital communication system as described above, and the voice frame synchronization timing and frequency hopping synchronization of the wireless communication apparatus according to the present embodiment based on the communication signal having this data configuration. FIG. 4 is an explanatory diagram showing timing. In the upper part of FIG. 2, reference numeral 20 denotes an audio frame formed by the audio encoding processing unit 2, reference numeral 21 denotes a guard time (GD) added for each frequency hopping, which is necessary for frequency switching, and reference numerals 22 and 2
Reference numeral 3 denotes a preamble and a UW added to each audio frame formed by the audio encoding processing unit 2, and the lower part of FIG. 2 shows an audio frame synchronization timing and a frequency hopping synchronization timing based on a communication signal having a data configuration shown in the upper part. . As described above, in the wireless communication apparatus according to the present embodiment, the speech frame period T _F of the speech encoding processing unit 2 is used.
And the frequency hopping period T _FH of the FH modulator 6, and a preamble 22 and a UW 23 common to each audio frame 20 as shown in FIG. It is unnecessary to add the frame pattern (V) to the audio frame.

Next, the receiving operation will be described. The transmission signal from the communication partner received by the antenna unit 10 (the signal subjected to the primary modulation by the digital modulation unit and the secondary modulation by the frequency hopping modulation unit) is received by the reception unit 1
After the amplification processing by 1 is performed, the conversion to the fixed frequency is performed by the FH demodulation unit 12 as in the case of the analog communication. By the FH demodulation processing of the FH demodulation unit 12, an original digital modulation signal having a fixed frequency is obtained. The original digital modulation signal output from the FH demodulation unit 12 is input to the digital demodulation unit 15 via the reception-side switching unit 13,
Here, digital demodulation processing is performed. By the digital demodulation processing of the digital demodulation unit 15, the original audio frame 20 is reproduced.
Is reproduced, and the preamble 22 and the UW 23 added to the audio frame 20 can be detected. Note that the original audio frame 20 reproduced by the digital demodulation unit 15 is output to the audio encoding processing unit 16, but the preamble 2
2 and UW 23 are output to the communication control unit 18 (not shown). The communication control unit 18 controls a decoding process of the audio decoding processing unit 16 described later based on the detected preamble 22 and UW 23.

That is, the communication control unit 18 detects the detected U
The audio decoding unit 16 instructs the audio decoding unit 16 to decode the audio frame 20 in synchronization with the detection timing of W23.
The decoding process of the audio frame 20 is performed at the frame synchronization timing synchronized with the detection timing of No. 3. As described above, in the wireless communication device according to the present embodiment, the frame of the audio encoding processing unit 2 is synchronized so that the frame synchronization period T _F of the audio encoding processing unit 2 is synchronized with the frequency hopping period T _FH of the FH modulation unit 6. Since the synchronization timing is controlled, the original audio data transmitted from the communication partner is continuously reproduced by decoding the audio frame 20 synchronized with the detection timing of the UW 23 added to each audio frame 20. be able to. The reproduced audio data is sequentially subjected to D / A conversion processing by a D / A converter, and is converted into an original analog audio signal. The converted original analog audio signal is output from an output of a speaker or the like via the output switching unit 17 to the outside.

As described above, in the wireless communication apparatus according to the present embodiment, the decoding process of the audio frame synchronized with the detection timing of the UW 23 added to the audio frame 20 is performed, so that the frame pattern unique to the audio encoding process is used. The audio data can be extracted without performing the audio frame synchronization processing according to (V), and the time t3 required for the audio frame synchronization processing shown in FIG. 10 can be eliminated. FIG. 3 is an explanatory diagram for explaining the time required until digital communication with a communication partner is started. As shown in FIG. 3, in the wireless communication device according to the present embodiment,
Digital communication with the communication partner can be started only in the time t1 required for detecting the UW23.

As described above, according to the radio communication apparatus according to the present embodiment, the frequency hopping timing signal of the FH modulator 6 is input to the speech coding processor 2 and the speech frame period T of the speech coding processor 2 is A transmission signal in which the frequency _F and the frequency hopping period T _FH of the FH modulation section 6 coincide with each other is transmitted to the communication partner, and when the transmission signal transmitted from the communication partner transmitted in this manner is decoded, the audio frame 2
0, ie, the detection timing of UW23,
Since the decoding process of the audio frame 20 synchronized with the frequency hopping period T _FH of the H demodulation unit 12 is performed, the time t1 required for the audio frame synchronization process can be made unnecessary, and prompt communication with the communication partner can be performed. Secure communication can be realized.

FIG. 4 is a system schematic diagram schematically showing an outline of a wireless communication system to which the wireless communication apparatus according to the present embodiment is applied, for example. In FIG.
1 to 26 are radio communication apparatuses according to the present embodiment shown in FIG. 1, 27 and 28 are base stations, and 29 is a public line network 30.
Etc. are connected to the exchange. The radio communication method according to the present embodiment includes a portable radio telephone system for making a call with a communication partner present in another communication area via base stations 27 and 28 and an exchange 29 as shown in FIG. The present invention is applied to a private wireless communication device or the like that performs a call with a communication partner within the same. Further, the same applies to each wireless communication device according to the other embodiments described below, and the wireless communication device according to each embodiment is applied to, for example, a wireless communication system as shown in FIG.

Embodiment 2 FIG. Next, another embodiment of the present invention will be described. In the wireless communication device according to the above embodiment, the preamble 22 and the UW 23 detected based on the demodulation processing by the digital demodulation unit 15 are transmitted to the communication control unit 18.
The communication control unit 18 is configured to instruct frame synchronization timing of the audio decoding processing unit 16 based on the notified UW 23, but the digital demodulation unit 1
The UW 23 detected in step 5 may be directly notified to the audio decoding processing unit 16, and the UW 23 directly notified from the digital demodulation unit 15 may be configured so that the audio decoding processing unit 16 performs frame synchronization processing.

FIG. 5 is a block diagram showing a wireless communication apparatus according to the present embodiment. In FIG. 5, reference numeral 16b denotes an audio frame 2 based on the notified UW23, which is directly notified of the UW23 output from the digital demodulation processing unit 15.
This is an audio decoding processing unit that performs frame synchronization processing or decoding processing of 0. In the figure, the same reference numerals denote the same or corresponding parts, and a detailed description thereof will be omitted. As shown in FIG. 5, in the wireless communication apparatus according to the present embodiment, the preamble 22 and the UW 23 detected based on the demodulation processing of the digital demodulation unit 15 are directly notified to the audio decoding processing unit 16 and the audio encoding processing unit 2 performs frame synchronization processing by the UW 23 notified directly from the digital demodulation unit 15,
The audio frame output from the digital demodulation processing unit 15 is decoded according to the frame synchronization timing captured by the synchronization processing. The audio signal decoded by the audio decoding processing unit 16b and converted into an analog signal is output to the outside from a speaker or the like via the output switching unit 17.

As described above, according to the radio communication apparatus according to the present embodiment, the frequency hopping timing signal of FH modulator 6 is input to speech coding processor 2 and the speech frame period of speech coding processor 2 is A transmission signal in which T _F and the frequency hopping period T _FH of the FH modulation section 6 match is transmitted to the communication partner. Also, when decoding the transmission signal transmitted from the communication partner transmitted in this manner, an audio frame is transmitted. Since the decoding process of the audio frame 20 synchronized with the detection timing of the UW 23 added to the FW20, that is, the frequency hopping period T _FH of the FH demodulation unit 12, is performed, the time t1 required for the audio frame synchronization process is eliminated. And secure confidential communication with the communication partner can be realized quickly.

In the radio communication apparatus shown in FIG. 5, the UW 23 detected by the digital demodulation unit 15 is notified to the audio decoding processing unit 16 as it is, and the digital demodulation unit 1
Although the audio decoding processing unit 16 is configured to perform the frame synchronization processing by the UW 23 notified directly from 5,
The same effect can be obtained even if the frequency hopping timing signal from the FH demodulation unit 12 is directly notified. FIG. 6 is a block diagram showing a wireless communication apparatus configured to directly notify the audio decoding processing section 16 of the frequency hopping timing signal from the FH demodulation section 12.

Embodiment 3 Next, another embodiment of the present invention will be described. The wireless communication device according to each of the above embodiments is configured such that the audio frame 20 output from the audio encoding processing unit 2 is directly input to the digital modulation unit 15 and subjected to digital modulation. For this reason, the audio frame encoded by the audio encoding processing unit 2 may be subjected to encryption processing and then digitally modulated and transmitted to the communication partner. The wireless communication apparatus according to the present embodiment is configured so that an encoded voice frame is further subjected to encryption processing by an encryption processing unit to perform wireless communication with a communication partner.

FIG. 7 is a block diagram showing a radio communication apparatus according to the present embodiment. 7, a frequency hopping timing signal 31 is input from the FH modulator 6 in the same manner as the speech encoding
An encryption processing unit 32 performs an encryption process on the audio frame output from the FH modulation unit 6 with the frequency hopping period T _FH as an encryption period T _{A. A} digital modulation unit 32 is similar to the audio decryption processing unit 16. An encryption / decryption processing unit that performs an inverse encryption process on the encrypted data at an encryption start synchronization timing synchronized with the detection timing of the UW 23 detected based on the 15 digital modulation processes. In the drawings, the same reference numerals denote the same or corresponding parts, and a detailed description thereof will be omitted.

Next, the operation of starting a telephone call by digital communication will be described. As described above, the frequency hopping timing signal of the FH modulator 6 is input to the voice coding processor 2, and the frequency hopping cycle T _FH of the FH modulator 6 is changed to the voice frame cycle T _{F by the} voice coding processor 2. Is formed. In the wireless communication device according to each of the above embodiments, the audio frame encoded by the audio encoding processing unit 2 is directly input to the digital modulation unit 3, but in the wireless communication device according to the present embodiment, the confidentiality of the call signal is The audio frame output from the audio encoding unit 2 is input to the encryption processing unit 31 to further improve
The encryption processing unit 31 performs an encryption process for each audio frame. Each audio frame (hereinafter, referred to as encrypted data) encrypted by the encryption processing unit 31 is input to the FH modulation unit 6 via the transmission / reception-side switching unit 5 after digital modulation by the digital modulation unit 3.

Here, the frequency hopping timing signal from the FH modulator 6 is input to the encryption processor 31 in the same manner as the speech encoding processor 2, and the frequency of the FH modulator 6 is The audio frame is encrypted with the hopping period T _FH as the encryption period T _A. Note that in the wireless communication device according to the above embodiment, the preamble signal and the UW are added to the audio frame output from the audio encoding processing unit 2 and output. The encryption processing unit 3 adds a preamble signal for reproducing a clock necessary for digital decoding to the encrypted data output from the unit 31 and a UW for detecting the bit order of the audio frame.
1 is output.

FIG. 8 shows the data structure of a transmission signal transmitted via the digital communication system of the wireless communication apparatus according to the present embodiment, and voice frame synchronization of the wireless communication apparatus according to the present embodiment based on the communication signal having this data structure. timing,
It is explanatory drawing which shows an encryption start synchronous timing and a frequency hopping synchronous timing. In the upper part of FIG. 8, reference numeral 33 denotes encrypted data encrypted by the encryption processing unit 31, and an arbitrary encryption process is performed on the audio frame 20 from the audio encoding processing unit 2. The lower part of FIG. 2 shows the audio frame synchronization timing, the encryption start synchronization timing, and the frequency hopping synchronization timing based on the communication signal having the data configuration shown in the upper part.

As described above, in the radio communication apparatus according to the present embodiment, not only the speech frame period T _F of the speech encoding unit 2 but also the encryption period T _A of the encryption unit 31 are subjected to FH modulation. Frequency hopping period T of unit 6
_FH and the respective encrypted data 33 as shown in FIG.
By adding a common preamble 22 and a UW 23 to each of them, not only a frame pattern (V) unique to the audio encoding process but also an encryption start trigger required for the encryption synchronization process can be eliminated.

Next, the receiving operation will be described. The transmission signal from the communication partner whose frequency has been converted to the fixed frequency by the FH demodulation unit 12 is subjected to digital demodulation processing by the digital demodulation unit 15 so that the original encrypted data 33 is reproduced, the preamble 22 and the UW Is detected. The reproduced original encrypted data 33 is transmitted to the decryption processing unit 32.
The preamble 22 and the UW 23 are output to the communication control unit 18 (not shown). The communication control unit 18 detects the detected preamble 22
Decryption processing unit 32 described later based on the
Controls the encryption / decryption processing of.

That is, the communication control unit 18 detects the detected U
Instructs the encryption / decryption processing unit 32 to decrypt the encrypted data 33 synchronized with the detection timing of W23, and the encryption / decryption processing unit 32 receives a frame synchronization timing synchronized with the detection timing of UW23 according to an instruction from the communication control unit 18. Performs the decryption processing of the encrypted data 33. As mentioned above,
In the wireless communication device according to the present embodiment, the encryption processing unit 31
Because of the frequency hopping period T _FH cryptographic synchronization period T _A and FH modulation unit 6 is controlling the encryption start synchronization timing of the encryption processing section 31 so as to be synchronized, the encryption processing unit 31
Performs the decryption process of the encrypted data 33 synchronized with the detection timing of the UW 23 added to each encrypted data 33, thereby establishing cryptographic synchronization, and the original voice transmitted from the communication partner from the received encrypted data. Frames can be played.

The preamble 22 and the UW 23
, Each hopping frequency (k−1, k, k) together with the GD21 necessary for switching the hopping frequency as shown in FIG.
k + 1...) is added to the encrypted data 33, so even if a phenomenon called a bit slip occurs during a call with a communication partner, a hopping frequency after the hopping frequency at which the bit slip occurs, for example, It is possible to correct the encryption start synchronization timing based on the UW detection timing at the next hopping frequency.

In a conventional wireless communication apparatus, even if cryptographic synchronization is established and a confidential call of a communication partner is started, if a bit slip occurs during the call, it is impossible to maintain the confidential call due to loss of cryptographic synchronization thereafter. However, in the wireless communication apparatus according to the present embodiment, even if a bit slip occurs during a call with a communication partner, a UW23 is added for each hopping frequency, and by detecting this UW23, a periodic encryption start synchronization is performed. The timing can be corrected, and even if encryption synchronization is lost due to the occurrence of a bit slip, the encryption start synchronization timing is immediately corrected, so that confidential communication with the communication partner can be continued.

The original audio frame reproduced by the decryption processing of the encryption / decryption processing unit 32 is
And subjected to decoding processing by the audio decoding processing unit 16. As described above, in the wireless communication apparatus according to the present embodiment, the communication control unit 18 performs speech decoding so that the frame synchronization cycle _TF of the speech decoding processing unit 16 and the frequency hopping cycle _TFH of the FH modulation unit 6 match. Since the frame synchronization timing of the conversion processing unit 16 is controlled, the audio frame 2 is transmitted in the same manner as in the wireless communication apparatus according to the embodiment shown in FIG.
The original analog audio signal is reproduced from 0, and is output from an output of a speaker or the like via the output switching unit 17 to the outside.

As described above, in the wireless communication apparatus according to the present embodiment, the audio frame from the audio encoding processing unit 2 is further encrypted by the encryption processing unit 31, and the UW 23 added to the encrypted data 33. Since the decryption processing of the encrypted data 33 is performed in synchronization with the detection timing of, the audio frame can be reproduced without performing the encryption synchronization processing by detecting the encryption start trigger necessary for the encryption synchronization processing. The time t3 required for the audio frame synchronization processing and the time t2 required for the encryption synchronization processing shown in FIG. Therefore, even in the wireless communication device according to the present embodiment, digital communication with the communication partner can be started only in the time t1 required for detecting the UW 23 as shown in FIG.

As described above, according to the radio communication apparatus of the present embodiment, the frequency hopping timing signal of the FH modulator 6 is input not only to the voice encoding processor 2 but also to the encryption processor 31 and further encrypted. Synchronization period T _A of the conversion processing unit 31 and the frequency hopping period T of the FH modulation unit 6
A transmission signal whose _FH matches the transmission signal is transmitted to the communication partner, and when the transmission signal transmitted from the communication partner transmitted in this manner is decrypted, the UW2
3, the decryption process of the encrypted data 33 synchronized with the frequency hopping period T _FH of the FH demodulation unit 12 is performed, so that not only the time t1 required for the audio frame synchronization process but also the encryption synchronization process is performed. Can be eliminated, and prompt confidential communication with a communication partner can be realized.

Even if a bit slip occurs during a call with a communication partner, a UW 23 is added for each hopping frequency. By detecting the UW 23, it is possible to correct the synchronization start synchronization timing periodically. Even if the encryption synchronization is lost due to the occurrence of the bit slip, the encryption start synchronization timing is immediately corrected, so that the confidential communication with the communication partner can be continued.

Embodiment 4 FIG. Next, another embodiment of the present invention will be described. In the wireless communication device according to the above embodiment, the preamble 22 and the UW 23 detected based on the demodulation processing by the digital demodulation unit 15 are transmitted to the communication control unit 18.
The communication control unit 18 is configured to instruct the frame synchronization timing of the audio decoding processing unit 16 based on the notified UW 23, but the digital demodulation unit 15 is configured as in the wireless communication device illustrated in FIG. The UW 23 detected in is directly notified to the audio decryption processing unit 16 and the encryption / decryption processing unit 32, and the encryption / decryption processing unit 32 performs the encryption synchronization process using the UW 23 notified directly from the digital demodulation unit 15. You may comprise.

FIG. 9 is a block diagram showing a radio communication apparatus according to the present embodiment. In FIG. 9, the UW 23 output from the digital demodulation processing unit 15 is directly notified, and the encrypted data 3 32 b is displayed on the basis of the notified UW 23.
3 is an encryption processing unit that performs encryption / synchronization processing or decryption processing. As shown in FIG. 9, in the wireless communication apparatus according to the present embodiment, the preamble 22 and the UW 23 detected based on the demodulation processing of the digital demodulation section 15 are not only the speech decoding processing section 16 but also the encryption decoding processing section 32b. Directly, and the encryption / decryption processing unit 32 b
The encryption synchronization processing is performed by the UW 23 directly notified by the, and the encrypted data 33 output from the digital demodulation processing unit 15 is decrypted by the encryption start trigger captured by the synchronization processing. The audio frame decoded by the encryption / decryption processing unit 32b is output to the audio decoding processing unit 16
The audio signal decoded by b and converted into an analog signal is output to the outside from a speaker or the like via the output switching unit 17. In the drawings, the same reference numerals denote the same or corresponding parts, and a detailed description thereof will be omitted.

As described above, according to the radio communication apparatus of the present embodiment, the frequency hopping timing signal of FH modulator 6 is input to encryption
1 is transmitted to the communication partner in which the encryption synchronization period T _A of the F.1 and the frequency hopping period T _FH of the FH modulator 6 are matched, and the transmission and decryption of the transmission signal from the communication partner transmitted in this manner is performed. At the time of the encryption, the decryption process of the encrypted data 33 synchronized with the detection timing of the UW 23 added to the encrypted data 33, that is, the frequency hopping period T _FH of the FH demodulation unit 12, is performed. Can be eliminated, and prompt confidential communication with a communication partner can be realized.

As shown in FIG. 6, the frequency hopping timing signal from the FH demodulation unit 12 may be directly notified. In addition, by notifying directly to the audio decoding processing unit 16, the same effect as the wireless communication device according to the above-described embodiment shown in FIG. 5 can be obtained.

In the third embodiment. Or 4. In the wireless communication apparatus and the wireless communication method according to the above, both the audio frame synchronization timing of the audio encoding processing unit 2 and the encryption start synchronization timing of the encryption processing unit 31 are synchronized with the frequency hopping timing of the FH modulation unit 6. However, encryption of a voice frame may be a problem in security strength of a communication system. In this case, only the audio frame synchronization timing of the audio encoding processing unit 2 is configured to be synchronized with the frequency hopping timing of the FH modulation unit 6, and the encryption start synchronization timing of the encryption processing unit 31 is determined by the FH modulation unit 6. Generates an asynchronous encryption start synchronous trigger with the frequency hopping timing of
The decryption processing of the encrypted data 33 may be performed at the encryption start synchronization timing that is asynchronous with the frequency hopping timing of the FH modulator 6. With this configuration, it is possible to eliminate the time t3 required for the voice frame synchronization process while maintaining the security strength of the communication system by encrypting the voice frame. In this case, digital communication with the communication partner is started at the time t1 required for detecting the UW 23 and the encryption synchronization processing establishment processing, that is, the time t2 required for detecting the encryption start synchronization trigger.

[0049]

As described above, according to the first aspect of the present invention, at least the encoded audio data is digitally modulated, and the digitally modulated audio data is subjected to the secondary modulation by the frequency hopping modulator. In the wireless communication method of transmitting and receiving data to and from a communication partner, the audio data is transmitted by synchronizing the frame synchronization timing of the encoding processing with the frequency switching timing of the frequency hopping modulation unit, and the frequency hopping added to the audio data is performed. Since the audio data received by the synchronization signal common to the cycle is decoded, confidentiality can be improved, and prompt confidential communication with the communication partner can be started quickly.

According to the second aspect of the present invention, an analog modulator for analogly modulating an audio signal, a digital modulator for digitally modulating an encoded audio signal,
A frequency hopping modulator for switching and outputting the frequency of the primary modulation signal from the digital modulation unit or the analog modulation unit at a predetermined timing, and transmitting and receiving a secondary modulation signal from the frequency hopping modulation unit via the antenna unit Since the transmitting and receiving unit and the encoding processing unit that performs the encoding processing of the audio signal in synchronization with the frequency switching timing of the frequency hopping modulation unit are provided, the confidentiality can be improved, while the communication with the communication partner can be performed quickly. Start of secure communication can be realized.

According to the third aspect of the present invention, there is provided an encryption unit for performing an encryption process on the encoded data from the encoding unit, and the encryption process of the encryption unit is performed by the frequency hopping modulation. Since the synchronization is performed in synchronization with the frequency switching timing of the unit, the confidentiality can be further improved by adding an encryption function, while the confidential communication with the communication partner can be started quickly. Further, even if a bit slip occurs during a call with a communication partner and encryption synchronization is lost, the encryption start synchronization timing can be immediately corrected, and a confidential call with the communication partner can be continued.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram illustrating a wireless communication device according to an embodiment of the present invention.

FIG. 2 is a data configuration diagram showing a data configuration of a transmission signal transmitted via a digital communication system of the wireless communication device shown in FIG.

FIG. 3 is an explanatory diagram showing a time required until digital communication with a communication partner is started in the wireless communication device shown in FIG. 1;

FIG. 4 is a system schematic diagram of a wireless communication system to which the wireless communication device and the wireless communication method according to the present invention are applied;

FIG. 5 is a configuration block diagram showing a wireless communication device according to another embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration of a wireless communication apparatus according to another embodiment of the present invention.

FIG. 7 is a block diagram showing a configuration of a wireless communication apparatus according to another embodiment of the present invention.

8 is a data configuration diagram showing a data configuration of a transmission signal transmitted via a digital communication system of the wireless communication device shown in FIG.

FIG. 9 is a block diagram showing a configuration of a wireless communication apparatus according to another embodiment of the present invention.

FIG. 10 is a flowchart illustrating a processing procedure when a conventional wireless communication device switches from analog communication to digital communication.

[Explanation of symbols]

2 audio coding processing section, 3 digital modulation section, 4 analog modulation section, 6 FH modulation section, 8 transmission section, 10 antenna section, 11 reception section, 12 FH demodulation section, 14 analog demodulation section, 15 digital demodulation section, 16 , 16b, 1
6c audio decoding processing unit, 20 audio frames, 24,
25, 26 wireless communication device, 31 encryption processing unit, 3
2, 32b encryption / decryption processing unit, 33 encrypted data.

Claims (3)

[Claims] 1. A wireless communication method for digitally modulating at least encoded audio data, and performing secondary modulation by a frequency hopping modulator on the digitally modulated audio data to transmit / receive to / from a communication partner. The audio data is transmitted by synchronizing the frame synchronization timing of the encoding process with the frequency switching timing of the frequency hopping modulator, and the audio data received by the common synchronization signal with the frequency hopping cycle added to the audio data is decoded. A wireless communication method. 2. An analog modulation section for analogly modulating an audio signal, a digital modulation section for digitally modulating an encoded audio signal, and a frequency of the digital modulation section or a primary modulation signal from the analog modulation section. A frequency hopping modulator for switching and outputting at a predetermined timing, a transmitting and receiving unit for transmitting and receiving a secondary modulation signal from the frequency hopping modulator via an antenna unit, and a voice synchronized with the frequency switching timing of the frequency hopping modulator. A wireless communication device comprising: an encoding processing unit that performs the encoding processing of the signal. 3. An encryption unit for performing an encryption process on the encoded data from the encoding unit, and the encryption process of the encryption unit is performed in synchronization with a frequency switching timing of the frequency hopping modulation unit. 2. The wireless communication device according to claim 1, wherein: