JP2006279217A - Radio communication terminal, radio base station, and communication apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio communication terminal capable of saving power consumption, while securing the secret of user data, and to provide a radio base station and a communication apparatus. <P>SOLUTION: The radio communication terminal 100 exchanges the user data generated in a high-order layer and control data required for reproducing the user data with the radio base station by using a prescribed radio communication system. The terminal 100 including an encoding/decoding processing part 105 for encoding only the control data transmits the user data and the encoded control data which is encoded by the encoding/decoding processing part 105 to the radio base station. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a radio communication terminal, a radio base station, and a communication apparatus including a transmission / reception unit that transmits and receives user data generated in an upper layer and control data necessary for reproducing the user data using a predetermined radio communication scheme About.

  Conventionally, in a mobile communication system using a predetermined wireless communication method such as W-CDMA, wireless frames are transmitted and received between a wireless communication terminal such as a mobile phone and a wireless base station.

  In the radio frame, a control channel (DPCCH) used for transmission / reception of control data such as pilot bits used for channel estimation in synchronous detection and TFCI (transport format combination indicator) indicating an effective data length in the radio frame, A user channel (DPDCH) used for transmission / reception of user data generated in an upper layer is multiplexed.

In such a mobile communication system, in order to ensure the confidentiality of the contents of the user channel multiplexed in the radio frame, generally user data transmitted and received using the user channel is encrypted (for example, Patent Literature 1).
JP-T 2002-539490 (pages 19-25, FIGS. 3 and 6)

  However, the conventional method described above has the following problems. That is, the load of encryption processing of user data transmitted and received using the user channel is high, and there is a problem that power consumption increases particularly in a portable wireless communication terminal equipped with a battery with a limited capacity.

  Therefore, the present invention has been made in view of such a situation, and provides a wireless communication terminal, a wireless base station, and a communication apparatus that can suppress power consumption while ensuring the confidentiality of user data. For the purpose.

  In order to solve the problems described above, the present invention has the following features. First, the first feature of the present invention is that user data generated in an upper layer and control data necessary for reproduction of the user data are transmitted between a radio base station (radio base station 200) and a predetermined radio frequency. A wireless communication terminal (wireless communication terminal 100) including a transmission / reception unit (spreading processing unit 107) that transmits and receives using a communication method (for example, W-CDMA mobile communication method), and encrypts the control data (Encryption / decryption processing unit 105), wherein the transmission / reception unit transmits the encryption control data and the user data encrypted by the encryption processing unit to the radio base station.

  According to such a feature, only control data having a smaller amount of information than user data is subject to encryption processing. For this reason, the load of encryption processing can be reduced compared with the case where user data is encrypted.

  That is, according to such a feature, it is possible to suppress power consumption associated with cryptographic processing, and in particular, it is possible to extend the communicable time of a portable wireless communication terminal equipped with a battery with a limited capacity. it can.

  In addition, since control data (pilot bits and TFCI) necessary for reproducing user data is encrypted, a certain level of confidentiality of user data can be ensured even if the user data is not encrypted.

  That is, even when the modulated user data is intercepted, the control data cannot be acquired, and thus the user data cannot be reproduced normally.

  The second feature of the present invention is related to the first feature of the present invention, wherein the control data includes a user data synchronization signal (pilot bit) used for determination of a specific position of the user data. And

  A third feature of the present invention relates to the first feature or the second feature of the present invention, and is summarized in that the encryption processing unit encrypts the control data using a common key encryption method.

  A fourth feature of the present invention relates to the first to third features of the present invention, and is summarized in that the user data and the encryption control data are multiplexed in a radio frame having a predetermined period.

  A fifth feature of the present invention relates to the first to fourth features of the present invention, and is related to a decryption processing unit (encryption unit) for decrypting encryption control data received from the radio base station via the predetermined radio communication system. The gist is to further include a decoding processing unit 105).

  A sixth feature of the present invention relates to the first to fifth features of the present invention, and transmits a control data encryption correspondence notification indicating that the control data encryption processing is supported to the radio base station. The gist of the present invention is to further include a correspondence availability notification transmission unit.

  A seventh feature of the present invention is that a predetermined wireless communication method is used for transmitting user data generated in an upper layer and control data necessary for reproducing the user data to and from a wireless communication terminal (wireless communication terminal 100). A wireless base station (wireless base station 200) including a transmission / reception unit (spreading processing unit 207) that transmits and receives using (for example, W-CDMA mobile communication system), and an encryption processing unit (encryption) that encrypts the control data A decryption processing unit 205) is provided, and the transmission / reception unit transmits the encryption control data and the user data encrypted by the encryption processing unit to the wireless communication terminal.

  An eighth feature of the present invention relates to the seventh feature of the present invention, wherein the control data includes a user data synchronization signal (pilot bit) used for determination of a specific position of the user data. And

  A ninth feature of the present invention relates to the seventh or eighth feature of the present invention, and is summarized in that the encryption processing unit encrypts the control data using a common key encryption method.

  A tenth feature of the present invention relates to the seventh to ninth features of the present invention, and is summarized in that the user data and the encryption control data are multiplexed in a radio frame having a predetermined period.

  An eleventh feature of the present invention relates to the seventh to tenth features of the present invention, and is a decryption processing unit (encryption unit) for decrypting encryption control data received from the wireless communication terminal via the predetermined wireless communication method. The gist is to further include a decoding processing unit 205).

  A twelfth feature of the present invention relates to the seventh to eleventh features of the present invention, in which the control data encryption support notification indicating that the wireless communication terminal supports encryption processing of the control data is sent. Based on the control data encryption correspondence notification received by the control data encryption correspondence reception unit (correspondence notification reception unit 209) received from the wireless communication terminal and the correspondence availability notification reception unit, the control data is encrypted. The gist of the present invention is that it further includes an encryption processing determination unit (encryption / decryption processing unit 205) for determining whether or not.

  A thirteenth feature of the present invention is a communication apparatus (for example, a transmission / reception unit that transmits and receives user data generated in an upper layer and control data necessary for reproducing the user data using a predetermined wireless communication method) A special-purpose IC implemented in the wireless communication terminal 100, comprising an encryption processing unit that encrypts the control data, wherein the transmission / reception unit includes the encrypted control data encrypted by the encryption processing unit and the encryption data The gist is to transmit user data.

  A fourteenth feature of the present invention relates to the thirteenth feature of the present invention, and is summarized in that the control data includes a user data synchronization signal used for determining a specific position of the user data.

  A fifteenth feature of the present invention relates to the thirteenth or fourteenth feature of the present invention, and is summarized in that the encryption processing unit encrypts the control data using a common key encryption method.

  A sixteenth feature of the present invention relates to the thirteenth to fifteenth features of the present invention, and is summarized in that the user data and the encryption control data are multiplexed in a radio frame having a predetermined period.

  A seventeenth feature of the present invention relates to the thirteenth to sixteenth features of the present invention, and further includes a decryption processing unit for decrypting encryption control data received from another communication device via the predetermined wireless communication method. The gist is to provide.

  According to the features of the present invention, it is possible to provide a wireless communication terminal, a wireless base station, and a communication device that can suppress power consumption while ensuring the confidentiality of user data.

  Next, an embodiment of the present invention will be described. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and ratios of dimensions and the like are different from actual ones.

  Accordingly, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

(Overall configuration of mobile communication system)
FIG. 1 shows an overall schematic configuration of a mobile communication system according to the present embodiment. As shown in FIG. 1, the mobile communication system according to the present embodiment is a mobile communication system using a W-CDMA mobile communication system, and includes a radio communication terminal 100 and a radio base station 200.

  In FIG. 1, only one radio communication terminal 100 and one radio base station 200 are shown, but the mobile communication system includes a plurality of radio communication terminals 100 and radio base stations 200. Of course, it is also good.

  In this embodiment, as shown in FIG. 1, the wireless communication terminal 100 is a mobile phone, but the wireless communication terminal 100 includes a portable information terminal equipped with a communication card using a W-CDMA mobile communication system, It may be a personal computer or the like.

(Logical block configuration of mobile communication system)
Next, the logical block configuration of the mobile communication system according to the present embodiment will be described. FIG. 2 is a logical block configuration diagram of the wireless communication terminal 100. FIG. 3 is a logical block configuration diagram of the radio base station 200.

  Hereinafter, portions related to the present invention will be mainly described. Therefore, when the radio communication terminal 100 shown in FIG. 2 and the radio base station 200 shown in FIG. 3 include a logical block (power supply unit or the like) that is not shown in the drawing or that is not described, which is essential for realizing the functions of the device. Please note that there is.

(1) Wireless Communication Terminal As shown in FIG. 2, the wireless communication terminal 100 includes an I channel modulation processing unit 101, a Q channel modulation processing unit 103, an encryption / decryption processing unit 105, a spreading processing unit 107, and a correspondence notification transmission unit 109. It has.

  The I channel modulation processing unit 101 performs modulation processing of user data (see FIG. 4) generated in an upper layer (for example, an application layer).

  Specifically, the I channel modulation processing unit 101 controls the user channel (DPDCH) used for transmission / reception of user data and control data necessary for reproducing user data, specifically, pilot bits and TFCI (transport format combination). In a radio frame multiplexed with a control channel (DPCCH) used for transmission / reception such as indicator), user data is phase-modulated (data modulation mapping) by QPSK or the like.

  The Q channel modulation processing unit 103 performs phase modulation (data modulation mapping) of control data using QPSK or the like in a radio frame in which a user channel (DPDCH) and a control channel (DPCCH) are multiplexed.

  The encryption / decryption processing unit 105 encrypts the control data modulated by the Q channel modulation processing unit 103. Also, the encryption / decryption processing unit 105 receives the encryption control data output from the diffusion processing unit 107, that is, the control data encrypted by the radio base station 200, and decrypts the received encryption control data.

  In the present embodiment, the encryption / decryption processing unit 105 constitutes an encryption processing unit that encrypts only control data. The encryption / decryption processing unit 105 constitutes a decryption processing unit that decrypts the encryption control data received from the radio base station.

  Specifically, the encryption / decryption processing unit 105 encrypts the control data modulated by the Q channel modulation processing unit 103 using a common key encryption method such as DES, or the encryption data output from the diffusion processing unit 107. Decryption control data.

  The spread processing unit 107 controls the user data subjected to data modulation mapping by the I channel modulation processing unit 101 and the control data (encrypted by the encryption / decryption processing unit 105 after data modulation mapping by the Q channel modulation processing unit 103). Control data) diffusion processing is executed.

  Specifically, the spreading processing unit 107 performs spreading processing of user data and encryption control data subjected to data modulation mapping using a predetermined spreading code.

  The spreading processing unit 107 receives a radio signal that has been subjected to spreading processing by the radio base station 200, and synchronizes the spreading code of the received radio signal with the replica of the spreading code included in the spreading processing unit 107, and reversely Perform diffusion processing.

  Further, the spreading processing unit 107 performs despreading processing, whereby the user data subjected to data modulation mapping is transmitted to the I channel modulation processing unit 101, and the encryption control data subjected to data modulation mapping is transmitted to the encryption / decryption processing unit 105. Output each. Note that the diffusion processing unit 107 can separate and combine a plurality of multipath components and correct a phase variation caused by fading variation (RAKE combining).

  In the present embodiment, the spread processing unit 107 constitutes a transmission / reception unit that transmits and receives user data and control data to and from the radio base station 200 using the W-CDMA mobile communication method (predetermined radio communication method). .

  The correspondence notification transmission unit 109 transmits a control data encryption correspondence notification indicating whether or not the wireless communication terminal 100 supports control data encryption processing to the wireless base station 200.

  Specifically, the correspondence notification transmission unit 109 transmits a control data encryption correspondence notification when the wireless communication terminal 100 establishes a communication path with the wireless base station 200.

(2) Radio Base Station As shown in FIG. 3, the radio base station 200 includes an I channel modulation processing unit 201, a Q channel modulation processing unit 203, an encryption / decryption processing unit 205, a spreading processing unit 207, and a correspondence notification receiving unit 209. It has.

  As shown in FIGS. 2 and 3, the radio base station 200 has a logical block configuration generally similar to that of the radio communication terminal 100 with respect to transmission / reception of user data and control data. Therefore, hereinafter, description of logical blocks that provide functions similar to those of the wireless communication terminal 100 described above will be omitted, and logical blocks that provide functions different from the wireless communication terminal 100 will be described.

  The encryption / decryption processing unit 205 has the following functions in addition to the functions provided by the encryption / decryption processing unit 105 of the wireless communication terminal 100 described above.

  That is, the encryption / decryption processing unit 205 determines whether to encrypt the control data to be transmitted to the wireless communication terminal 100 based on the control data encryption correspondence notification received from the wireless communication terminal 100 by the correspondence notification receiving unit 209. judge. In the present embodiment, the encryption / decryption processing unit 205 constitutes an encryption processing determination unit.

  The correspondence notification receiving unit 209 receives a control data encryption correspondence notification indicating whether or not a wireless communication terminal (for example, the wireless communication terminal 100) supports control data encryption processing from the wireless communication terminal.

  Specifically, the correspondence notification receiving unit 209 sends a control data encryption correspondence notification from a wireless communication terminal (for example, the wireless communication terminal 100) when the wireless base station 200 establishes a communication path with the wireless communication terminal 100. The control data encryption correspondence notification received is output to the encryption / decryption processing unit 205.

(Configuration of radio frame)
Next, with reference to FIGS. 4A to 4C, a configuration of a radio frame transmitted and received between the radio communication terminal 100 and the radio base station 200 described above will be described.

  4A to 4C show the configuration of an “uplink” radio frame transmitted from the radio communication terminal 100 toward the radio base station 200. FIG. Note that the “downlink” radio frame transmitted from the radio base station 200 to the radio communication terminal 100 is less than the “uplink” radio frame shown in FIGS. 4A to 4C. The control channel multiplexing method and the contents of control data are partially different.

  As shown in FIG. 4A, the radio frame has a period of 10 ms, and a plurality of radio frames multiplexed with user channels or control channels are sequentially transmitted and received. A radio frame is the minimum unit of encryption processing and decryption processing.

  Also, as shown in FIG. 4B, in the user channel (DPDCH), the transfer bit rate (Ndata / frame) per radio frame is variable. For example, when high-speed data transmission is required, a transfer bit rate of several hundred kbps to several Mbps can be realized.

  On the other hand, as shown in FIG. 4C, in the control channel (DPCCH), the transfer bit rate per radio frame is fixed to 150 bits / frame (15 kbps). That is, the transfer bit rate of control data transmitted and received in the control channel is considerably low compared to the user channel.

  Control data transmitted and received in the control channel includes pilot bits (user data synchronization signal), TFCI, and the like. In addition to the pilot bits and TFCI, there is a transmission power control (TPC) command and feedback information (FBI).

  As described above, the pilot bits are used for channel estimation in synchronous detection. That is, fluctuations in the phase and amplitude of the received radio signal are estimated by the pilot bits. Once the phase and amplitude variations of the received radio signal are estimated, the specific location of the user data can be determined and user data synchronization can be established.

  The TFCI indicates the effective data length in the radio frame. The TFCI indicates the number of user channels multiplexed in a radio frame and the type of transmission format used in each user channel.

(Operation of mobile communication system)
Next, the operation of the mobile communication system described above will be described with reference to FIG. FIG. 5 shows a state transition when the wireless communication terminal 100 and the wireless base station 200 establish a communication path.

  When the radio communication terminal 100 and the radio base station 200 establish a communication path, connection processing is executed between the radio communication terminal 100 and the radio base station 200. When the connection process is started, the state shifts from the idle state S1 to the setup state S2.

  In the setup state S2, the wireless communication terminal 100 transitions to the key exchange state S3 or transitions to the normal mode state S4 based on whether or not the “control data encryption correspondence notification” is transmitted to the wireless base station 200. Is determined.

  The normal mode state S4 is a mode in which user data and control data are not encrypted and transmitted and received as plain text. In the normal mode state S4, only the user data may be encrypted instead of the control data.

  In the key exchange state S3, an encryption key (common key) used for encrypting the control data is exchanged between the radio communication terminal 100 and the radio base station 200.

  When the exchange of the encryption key (common key) is completed between the wireless communication terminal 100 and the wireless base station 200, the state shifts to the encryption communication mode state S5 in which the control data is encrypted using the encryption key.

  After shifting to the encryption communication mode state S5, user data is transmitted and received without encryption processing between the wireless communication terminal 100 and the wireless base station 200, and only control data is encrypted with the encryption key.

(Action / Effect)
According to the mobile communication system according to the present embodiment described above, only control data having a smaller amount of information than user data is subject to encryption processing. For this reason, the load of encryption processing can be reduced compared with the case where user data is encrypted.

  That is, according to the mobile communication system according to the present embodiment, the power consumption associated with the encryption process can be suppressed, and therefore, particularly the communication possible time of the wireless communication terminal 100 equipped with a battery with a limited capacity is extended. be able to.

  In addition, since control data (pilot bits and TFCI) necessary for reproducing user data is encrypted, a certain level of confidentiality of user data can be ensured even if the user data is not encrypted.

  That is, even when the modulated user data is intercepted, the control data cannot be acquired, and thus the user data cannot be reproduced normally.

  Furthermore, according to the mobile communication system according to the present embodiment, the control data is encrypted using the common key encryption method, so that the control data encryption processing is performed compared to the case where the public key encryption method such as RSA is used. Can be further reduced.

  Also, according to the mobile communication system according to the present embodiment, a control data encryption support notification indicating that the control data encryption process is supported is transmitted from the radio communication terminal 100 to the radio base station 200.

  For this reason, even when a wireless communication terminal supporting control data encryption processing and a wireless communication terminal not supporting control data encryption processing coexist in the mobile communication system, control data encryption Control data encryption processing can be executed only between the wireless communication terminal supporting the processing and the wireless base station 200.

(Other embodiments)
As described above, the content of the present invention has been disclosed through one embodiment of the present invention. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments will be apparent to those skilled in the art.

  For example, in the above-described embodiment of the present invention, the mobile communication system using the W-CDMA mobile communication system has been described as an example, but the scope of the present invention is applicable to a mobile communication system using the W-CDMA mobile communication system. It is not limited.

  The present invention provides not only a mobile communication system using a W-CDMA mobile communication system but also user data generated in an upper layer and control data necessary for reproduction of the user data between radio base stations. The present invention can be applied to a system that transmits and receives using a wireless communication method.

  In the above-described embodiment of the present invention, the common key encryption method is used for the control data encryption processing. However, the control data encryption processing may not necessarily use the common key encryption method.

  Further, in the above-described embodiment of the present invention, the control data encryption support notification indicating that the wireless communication terminal 100 supports control data encryption processing is transmitted to the wireless base station 200. It is possible to adopt a form in which the encryption correspondence notification is not transmitted.

  In the above-described embodiment of the present invention, the radio communication terminal 100 and the radio base station 200 have been described as examples. However, the present invention is mounted on a radio communication terminal, a radio base station, or a portable information terminal or a personal computer. It can also be provided as a communication device such as a special purpose IC mounted on a communication card.

  As described above, the present invention naturally includes various embodiments that are not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

1 is an overall schematic configuration diagram of a mobile communication system according to an embodiment of the present invention. It is a logic block block diagram of the radio | wireless communication terminal which concerns on embodiment of this invention. It is a logic block block diagram of the wireless base station which concerns on embodiment of this invention. It is a block diagram of the radio | wireless frame transmitted / received in the mobile communication system which concerns on embodiment of this invention. It is a state transition diagram of the mobile communication system according to the embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Wireless communication terminal, 101 ... I channel modulation process part, 103 ... Q channel modulation process part, 105 ... Encryption / decryption process part, 107 ... Spreading process part, 109 ... Correspondence notification transmission part, 200 ... Radio base station, 201 ... I channel modulation processing unit, 203 ... Q channel modulation processing unit, 205 ... encryption / decryption processing unit, 207 ... spreading processing unit, 209 ... corresponding notification receiving unit

Claims (17)

A wireless communication terminal including a transmission / reception unit that transmits / receives user data generated in an upper layer and control data necessary for reproducing the user data to / from a wireless base station using a predetermined wireless communication method. ,
An encryption processing unit for encrypting only the control data;
The transmission / reception unit is a wireless communication terminal that transmits the encryption control data encrypted by the encryption processing unit and the user data to the wireless base station.   The wireless communication terminal according to claim 1, wherein the control data includes a user data synchronization signal used for determining a specific position of the user data.   The wireless communication terminal according to claim 1, wherein the encryption processing unit encrypts the control data using a common key encryption method.   The radio communication terminal according to any one of claims 1 to 3, wherein the user data and the encryption control data are multiplexed in a radio frame having a predetermined cycle.   The wireless communication terminal according to any one of claims 1 to 4, further comprising a decryption processing unit that decrypts encryption control data received from the wireless base station via the predetermined wireless communication system.   The radio according to any one of claims 1 to 5, further comprising a correspondence availability notification transmission unit that transmits a control data encryption correspondence notification indicating that the control data encryption processing is supported to the radio base station. Communication terminal. A radio base station comprising a transmission / reception unit that transmits / receives user data generated in an upper layer and control data necessary for reproducing the user data to / from a radio communication terminal using a predetermined radio communication method. ,
An encryption processing unit for encrypting only the control data;
The transmission / reception unit is a radio base station that transmits the encryption control data encrypted by the encryption processing unit and the user data to the radio communication terminal.   The radio base station according to claim 7, wherein the control data includes a user data synchronization signal used for determining a specific position of the user data.   The radio base station according to claim 7 or 8, wherein the encryption processing unit encrypts the control data using a common key encryption method.   The radio base station according to claim 7, wherein the user data and the encryption control data are multiplexed in a radio frame having a predetermined period.   The radio base station according to claim 7, further comprising a decryption processing unit that decrypts encryption control data received from the radio communication terminal via the predetermined radio communication method. A control data encryption correspondence notification receiving unit that receives from the wireless communication terminal a control data encryption correspondence notification indicating that the wireless communication terminal supports encryption processing of the control data;
12. The encryption processing determination unit according to claim 7, further comprising: an encryption processing determination unit that determines whether to encrypt the control data based on the control data encryption correspondence notification received by the correspondence availability notification reception unit. The radio base station according to item. A communication device including a transmission / reception unit that transmits and receives user data generated in an upper layer and control data necessary for reproducing the user data using a predetermined wireless communication method,
An encryption processing unit for encrypting only the control data;
The transmission / reception unit is a communication device that transmits the encryption control data encrypted by the encryption processing unit and the user data.   The communication apparatus according to claim 13, wherein the control data includes a user data synchronization signal used for determining a specific position of the user data.   The communication apparatus according to claim 13 or 14, wherein the encryption processing unit encrypts the control data using a common key encryption method.   The communication apparatus according to any one of claims 13 to 15, wherein the user data and the encryption control data are multiplexed in a radio frame having a predetermined period.   The communication device according to any one of claims 13 to 16, further comprising a decryption processing unit that decrypts encryption control data received from another communication device via the predetermined wireless communication method.

Images