Secret Key Agreement Scheme Based on BER Fluctuation in Radio Communication System
Takayasu K
ITANO*, Hisato I
WAI*and Hideichi S
ASAOKA*(Received July 13, 2009)
This paper proposes a private key agreement scheme using the fluctuations of BER (Bit Error Rate). In the proposed scheme, the received BER at both authorized users is used as the common information for key generation between them. BER is an appropriate indicator to characterize the wireless channel because it includes all factors to generate bit errors such as fluctuations of amplitude and phase, effect of delayed waves etc. In order to evaluate the performance of the proposed scheme, numerical simulations are carried out assuming the configurations and the parameters of wireless LAN system. The results of the simulations show that the proposed scheme successfully achieves the key agreement at SN ratio of 15dB when it is combined with data deletion and error correction schemes.
-G[YQTFU information security
, secret key agreement, pseudo BER, radio propagationࠠࡢ࠼
ᖱႎࠠࡘ࠹ࠖ㧘⒁ኒ㎛㧘ᡆૃࡆ࠶࠻⺋ࠅ₸㧘㔚ᵄવ៝㒽⒖േㅢାߦ߅ߌࠆࡆ࠶࠻⺋ࠅ₸ᄌേߦၮߠߊ⒁ኒ㎛ᣇᑼ
ർ㊁ 㓉ᐽ㧘ጤ ⺈ੱ㧘╣ጟ ⑲৻
߹߃߇߈
ή✢ㅢାߩ᥉ߦ㧘⋑⡬ኻ╷ߥߤߩࠠࡘ
࠹ࠖኻ╷߇㊀ⷐߣߥߞߡࠆ㧚ㄭᐕߩ⋑⡬ኻ╷ߣߒ ߡ㧘ᖱႎࠍᥧภൻߒߡવㅍߔࠆᥧภㅢା߇৻⥸⊛ߢ
ࠅ㧘ㅍା⠪ߣฃା⠪߇ㅢߩᥧภ㎛ࠍ↪ࠆㅢ
㎛㧔⒁ኒ㎛㧕ᥧภᣇᑼ 1, 2) ߇ࠃߊ↪ࠄࠇߡࠆ㧚
ㅢ㎛ᥧภᣇᑼߪ㧘ㅍା⠪ߣฃା⠪߇ㅢߩ⒁ኒ㎛
ࠍ↪ߡᖱႎߩᥧภൻߣᓳภࠍⴕ߁ߚ㧘⸘▚㊂ߪ ዋߥ߇㧘ᥧภㅢାࠍⴕ߁೨ߦਔ⠪ߩ㑆ߢ⒁ኒ㎛ࠍ
ߒߡ߅ߊᔅⷐ߇ࠆ㧚⒁ኒ㎛ࠍߔࠆߚߦ
㎛㈩ㅍࠍⴕ߁ߎߣ߇ᄙ߇㧘ή✢ㅢାߢߪߘߩㆊ⒟
ߢ⒁ኒ㎛߇⋑⡬ߐࠇࠆෂ㒾ᕈ߇ࠅ㧘ోߥ⒁ኒ㎛
ᚻᴺ߇㊀ⷐߣߥࠆ㧚߹ߚ㧘ߒߚ⒁ኒ㎛ߪᥧ ภㅢାࠍⴕ߁ߚ߮ߦ↪ߔࠆߚ㧘หߓ⒁ኒ㎛ࠍ㐳 ᦼߦᷰߞߡ↪ߔࠆߣ㧘ᥧภൻᖱႎߩࡄ࠲ࡦ߆ࠄ
⒁ኒ㎛ࠍ⸃⺒ߐࠇࠆෂ㒾ᕈ߽ࠆ㧚
ߘߎߢ㧘㔚ᵄવ៝ߩ․ᓽࠍᵴ↪ߔࠆߎߣߢ㧘㎛ࠍ
㈩ㅍߔࠆߎߣߥߊน⢻ߢ㧘ᣂߚߥ⒁ኒ㎛ߩ↢ᚑ
߽ኈᤃߥ⒁ኒ㎛ᣇᑼ3-7)߇ឭ᩺ߐࠇߡࠆ㧚
৻⥸ߦ⒖േㅢାߦ߅ߡ㔚ᵄવ៝ߩนㅒᕈ߇ᚑ ࠅ┙ߟߎߣ㧘ࡑ࡞࠴ࡄࠬࡈࠚࠫࡦࠣߩᄌേ߇႐ᚲ ߦଐሽߔࠆߎߣ߆ࠄ㧘ㅍฃାዪ߇ߦାภߩㅍฃ
* Department of Electronics, Doshisha University, Kyotanabe, Kyoto, 610-0321, Japan Telephone: +81-774-65-6289, Fax: +81-774-65-6801, E-mail: eti1101@mail4.doshisha.ac.jp
ାࠍⴕ߁႐ว㧘વ៝〝․ᕈߪ⋧㑐ߩ㜞߽ߩߣߥࠆ ߇㧘႐ᚲ߇⇣ߥࠆઁዪߢߩવ៝〝․ᕈߪ⋧㑐߇ૐߊ
ߥࠆ8, 9)㧚ߎࠇࠃࠅ㧘ᱜⷙߩㅍାዪߣฃାዪߢߘࠇ
ߙࠇฃାାภᒝᐲ㧔RSSI: Received Signal Strength
Indicator
㧕ߥߤߩવ៝〝․ᕈࠍ᷹ቯߔࠆߣ㧘ᱜⷙዪ㑆ߢߪߦ㜞⋧㑐ߣߥࠆ߇㧘⋑⡬ዪߦߪૐ⋧㑐ߦ ߥࠆᖱႎ߇ᓧࠄࠇࠆ㧚ߘߎߢ㧘ᓧࠄࠇߚᖱႎߦ㑣୯ ࠍ⸳ቯߒ
2
୯ൻಣℂࠍⴕ߁ߣ㧘ᱜⷙዪߢߩߺน⢻ߥ⒁ኒ㎛߇↢ᚑߢ߈ࠆ㧚߹ߚ㧘㔚ᵄવ៝․ᕈࠍᵴ
↪ߒߡ↢ᚑߐࠇߚ⒁ኒ㎛ߪ㧘ౣ↢ᚑ߿߇ኈᤃߢ
ࠆߚ㧘⒁ኒ㎛ߩᝥߡ߽น⢻ߢࠆ㧚 㔚ᵄવ៝ࠍᵴ↪ߒߚ⒁ኒ㎛ᣇᑼߦ㑐ߒߡ㧘ߎ ࠇ߹ߢ㧘
OFDM
ߩᵄᢙ․ᕈࠍ↪ߚᣇᑼ6)㧘นᄌ ᜰะᕈࠕࡦ࠹࠽ߢࠆࠛࠬࡄࠕࡦ࠹࠽10) ࠍ↪ߚ ᣇᑼ7) ߥߤ߇ឭ᩺ߐࠇ㧘ᐢߊᬌ⸛ߐࠇߡࠆ㧚ߎࠇ ࠄߩ⎇ⓥߪ㧘㎛↢ᚑߩᖱႎߣߒߡRSSI
ࠍ↪ߡ㧘ߘߩᒝᐲᄌേߦၮߠߡ⒁ኒ㎛ࠍ↢ᚑߔࠆᣇᑼ ߢࠆ㧚⒁ኒ㎛↢ᚑߩߚߩᖱႎߣߒߡ
RSSI
ࠍ↪ࠆߣ㧘⋥ធᵄߥߤᡰ㈩⊛ߦߥࠆ㔚ᵄߩ⚻〝߇ ሽߔࠆⅣႺߦ߅ߡ㧘↢ᚑߒߚ⒁ኒ㎛ߩ⋑⡬⠴ᕈ ߇ૐਅߔࠆߎߣ߇ႎ๔ߐࠇߡࠆ11, 12)㧚ߘߎߢᧄ⺰ᢥߢߪ㧘⒁ኒ㎛↢ᚑߩߚߩᖱႎ ߣߒߡ㧘ᓥ᧪ࠃࠅᬌ⸛ߐࠇߡࠆ
RSSI
ߢߪߥߊ㧘 ࡆ࠶࠻⺋ࠅࠍ↪ߡ⒁ኒ㎛ࠍ↢ᚑߔࠆᣇᴺࠍឭ᩺ߔࠆ㧚․ߦ㧘ฃାዪߢߩߺ⊒↢ߐߖࠆߎߣ߇น⢻ߢ㧘 ࡆ࠶࠻⺋ࠅߣ߽㑐ଥߩࠆᡆૃࡆ࠶࠻⺋ࠅࠍ↪
ߡ⒁ኒ㎛ࠍ↢ᚑߔࠆᣇᑼ13)ߦߟߡᬌ⸛ߔࠆ㧚 ᧄ⺰ᢥߢߪ㧘߹ߕ㔚ᵄવ៝․ᕈࠍᵴ↪ߒߚ⒁ኒ㎛
ᣇᑼߦߟߡㅀߴ㧘ᰴߦ㧘ᡆૃࡆ࠶࠻⺋ࠅ₸ࠍ
↪ߚ⒁ኒ㎛ߩ↢ᚑ㧘߅ࠃ߮ߦߟߡᬌ⸛ߔࠆ㧚 ߘߒߡ㧘ή✢
LAN
ࠪࠬ࠹ࡓࠍᗐቯߒߚࠪࡒࡘ࡚ࠪࡦࠍⴕ㧘ឭ᩺ᣇᑼߩലᕈࠍ␜ߔ㧚
㔚ᵄવ៝․ᕈࠍᵴ↪ߒߚ⒁ኒ㎛
⒁ኒ㎛ߩේℂ
㔚ᵄવ៝․ᕈࠍᵴ↪ߒߚ⒁ኒ㎛ᣇᑼߢߪ㧘㔚 ᵄવ៝ߩ․ᓽ㧘ߟ߹ࠅ㧘㔚ᵄવ៝ߩนㅒᕈߣࡑ࡞࠴
ࡄࠬࡈࠚࠫࡦࠣߩ႐ᚲᤨ㑆ଐሽᕈࠍ↪ߒߡ
ࠆ㧚
Fig. 1
ߦ㧘㔚ᵄવ៝․ᕈࠍᵴ↪ߒߚ⒁ኒ㎛ᣇᑼߩේℂࠍ␜ߔ㧚㔚ᵄવ៝ߦ߅ߡ㧘ㅍฃାዪ߇
หߓ႐ᚲߢࠇ߫㧘ㅍାዪߣฃାዪ߇ઍߒߡ߽ห ߓ⚻〝ࠍ⚻ߡવ៝ߔࠆ㧔㔚ᵄવ៝ߩนㅒᕈ㧕㧚ߎࠇ ࠃࠅ㧘ାภࠍ
A
ዪ߆ࠄB
ዪ߳ㅍାߔࠆ႐วߣ㧘ߘ ߩㅒߩB
ዪ߆ࠄA
ዪ߳ㅍାߔࠆ႐วߢ㧘વ៝〝․ᕈߩ⋧㑐߇㕖Ᏹߦ㜞ߊߥࠆ㧚
৻ᣇ㧘ࡑ࡞࠴ࡄࠬⅣႺߦ߅ߡ㧘ฃାዪߩ႐ᚲ߇ ᄌࠊࠆߣ㔚ᵄવ៝ߩ⚻〝߽⇣ߥࠅ㧘વ៝〝․ᕈ߽⇣
ߥࠆ߽ߩߣߥࠆ㧔ࡑ࡞࠴ࡄࠬࡈࠚࠫࡦࠣߩ႐ᚲଐ ሽᕈ㧕㧚ߎࠇࠃࠅ㧘
Fig. 1
ߦ߅ߡ႐ᚲ߇⇣ߥࠆ⋑⡬ዪ㧔
Eavesdropper
㧕ߣᱜⷙዪ㧔B
ዪࠆߪA
ዪ㧕 ߢߪ㧘᷹ቯߒߚવ៝〝․ᕈߪ㕖Ᏹߦ⋧㑐ߩૐ߽ߩ ߣߥࠆ㧚ߎࠇࠄ㔚ᵄવ៝ߩ․ᓽߦࠃࠅ㧘વ៝〝․ᕈߩᖱႎ ߪᱜⷙዪ㑆㧔Aዪ̆Bዪ㑆㧕ߢߩߺน⢻ߣߥࠆ㧚 ߘߎߢ㧘ߎߩᖱႎߦ
2
୯ൻಣℂࠍⴕߞߡ⒁ኒ㎛ࠍ↢ᚑߔࠆߣ㧘㎛ߩ㈩ㅍࠍߔࠆߎߣߥߊ⒁ኒ㎛ߩ߇ น⢻ߢࠆ㧚
⒁ኒ㎛↢ᚑᚻ㗅
㔚ᵄࠍᵴ↪ߒߚ⒁ኒ㎛ᣇᑼߦ߅ߌࠆ⒁ኒ㎛
↢ᚑᚻ㗅ࠍ
Fig. 2
ߦ␜ߔ㧚Fig. 2ߢߪ㧘߹ߕ㧘⒁ኒ㎛ࠍߔࠆዪห჻ߢવ៝〝․ᕈ᷹ቯ↪ାภߩㅍ ฃାࠍ➅ࠅߒⴕ㧘⒁ኒ㎛ࠍ↢ᚑߔࠆߩߦᔅⷐߥ 㐳ߐߩવ៝〝․ᕈߩ♽ࠍᓧࠆ㧚ߘߒߡ㧘ᓧࠄࠇߚ વ៝〝․ᕈߩ♽ߦ
2
୯ൻಣℂࠍⴕߞߡ㎛ࠍ↢ᚑߔࠆ㧚ߎߎߢ㧘વㅍ〝ߦ߅ߌࠆ㔀㖸ߥߤߩᓇ㗀
Fig. 1. Principle of secret key agreement scheme
using channel characteristics.
Station A Station B
Eavesdropper Multipath fading
Sharing unique information
Different information
ߦࠃࠅ㧘ߩዪߢ↢ᚑߒߚ㎛ߦਇ৻⥌߇⊒↢
ߔࠆߎߣ߇ࠆ㧚ߎߩ႐วߦߪ㎛ߩਇ৻⥌⸓ᱜ ࠍⴕ㧘⸓ᱜᓟߩ㎛♽ࠍ⒁ኒ㎛ߣߒߡᥧภㅢାߦ
↪ߔࠆ㧚
ࡆ࠶࠻⺋ࠅ₸ᄌേߦၮߠߊ⒁ኒ㎛ᣇᑼ ࡆ࠶࠻⺋ࠅ₸ᄌേߦၮߠߊ⒁ኒ㎛ᣇᑼ
ᓥ᧪ߩᣇᑼ 5-7)ߢߪ㧘⒁ኒ㎛ࠍߔࠆዪ߇ߘࠇ ߙࠇRSSI
ࠍ᷹ቯߒ㧘RSSI
ߦኻߒߡߘߩਛᄩ୯ߥߤ ࠍ㑣୯ߣߒߡ2
୯ൻಣℂࠍⴕߞߡߚ㧚RSSIߦࠃ ࠅ⒁ኒ㎛ࠍ↢ᚑߔࠆ႐ว㧘ᱜⷙዪห჻ߣ⋑⡬ዪ߇ߦ⋥ធᵄߩ᧪ౝߦࠆߥߤᡰ㈩⊛ߥࡄࠬ߇ ሽߔࠆߣ㧘
RSSI
୯߽ᡰ㈩⊛ߥࡄࠬߦଐሽߒߡߒ߹⋑⡬ዪߢ߽ᱜⷙዪߢ᷹ቯߒߚ߽ߩߣ⋧㑐ߩ㜞
RSSI
߇ᓧࠄࠇࠆ12)㧚ߎߩࠃ߁ߦ㧘ᱜⷙዪ㑆ߣ⋑⡬ዪߢ㜞⋧㑐ߦߥࠆ
RSSI
ߦၮߠߡ⒁ኒ㎛ࠍ↢ᚑ ߔࠆߣ㧘⋑⡬ዪߢ߽ᱜⷙዪߢߒߡࠆ⒁ኒ㎛ߣ หߓ߽ߩ߇↢ᚑߐࠇࠆෂ㒾ᕈ߇ࠆ㧚ߘߎߢ㧘ᧄ⺰ᢥߢߪ⒁ኒ㎛ߩ↢ᚑߦ
RSSI
ࠍ↪ࠆߩߢߪߥߊ㧘ࡆ࠶࠻⺋ࠅߦၮߠߡ⒁ኒ㎛ࠍ↢ᚑ ߒߔࠆᚻᴺߦߟߡឭ᩺ߔࠆ㧚
ᡆૃࡆ࠶࠻⺋ࠅߩ⒁ኒ㎛↢ᚑ߳ߩㆡ↪
ࡆ࠶࠻⺋ࠅࠍ↪ߡ⒁ኒ㎛ࠍ↢ᚑߔࠆߦߪ㧘વㅍ
〝ߢ⊒↢ߔࠆഠൻⷐ࿃߿વ៝〝․ᕈߩᄌേߥߤࠍ
ࡆ࠶࠻⺋ࠅ₸ߦᤋߐߖࠆߎߣ߇㊀ⷐߢࠆ㧚߹ߚ㧘
⋑⡬ዪߦኻߒߡᔅⷐએߩᖱႎࠍਈ߃ߥߣ߁
ⷰὐ߆ࠄ㧘ࡆ࠶࠻⺋ࠅߪฃାߩߺߢᬌߢ߈ࠆ߽
ߩ߇ᦸ߹ߒ㧚ߘߎߢᧄ⺰ᢥߢߪ㧘ࡆ࠶࠻⺋ࠅߣߒ ߡ㧘ฃାᤨߦੱὑ⊛ߦࡆ࠶࠻⺋ࠅࠍ⊒↢ߐߖࠆᡆૃ
ࡆ࠶࠻⺋ࠅ14-20)ࠍ↪ࠆ㧚ᡆૃࡆ࠶࠻⺋ࠅߪ㧘ᖱႎ
ାภવㅍᤨߩવ៝〝․ᕈࠍផቯߔࠆᚻᴺߩ৻ߟߢ
ࠅ㧘વ៝〝ߩഠൻߦᔕߓߚㆡᔕᓮߥߤߦ↪ࠆ ߎߣ߇ᬌ⸛ߐࠇߡࠆ㧚
ߎߎߢ㧘ᡆૃࡆ࠶࠻⺋ࠅ⊒↢ࠪࠬ࠹ࡓߩࡉࡠ࠶ࠢ
࿑ࠍ
Fig. 3
ߦ␜ߔ㧚ฃାዪߦ߅ߡ㧘ฃାߒߚାภߦੱὑ⊛ߥᱡߺࠍਈ߃ߡᓳ⺞ߔࠆߣ㧘ฃାࡆ࠶࠻♽
߇ഠൻߒߚࠃ߁ߥ♽㧔ᡆૃࡆ࠶࠻⺋ࠅ♽㧕߇ ᓧࠄࠇࠆ㧚ߎߩᡆૃࡆ࠶࠻⺋ࠅ♽ߣ㧘ฃାାภࠍ ߘߩ߹߹ᓳ⺞ߒߚ࠺࠲♽㧔ฃାࡆ࠶࠻♽㧕ࠍ Ყセߔࠆߎߣߢᓧࠄࠇࠆࡆ࠶࠻⺋ࠅ₸߇ᡆૃࡆ࠶
࠻⺋ࠅ₸ߢࠆ㧚ߎߩᡆૃࡆ࠶࠻⺋ࠅ₸ࠍ⒁ኒ㎛↢
ᚑߩᖱႎߦ↪ࠆߎߣߢ㧘⒁ኒ㎛ߩ↢ᚑ߅ࠃ߮
߇น⢻ߦߥࠆߣ⠨߃ࠄࠇࠆ㧚
ߚߛߒ㧘ᓥ᧪ᬌ⸛ߐࠇߡࠆᡆૃࡆ࠶࠻⺋ࠅ⊒↢
ᴺߢߪ㧘㔀㖸߇㕖ᏱߦዊߐⅣႺߦ߅ߡᡆૃࡆ࠶
࠻⺋ࠅ߇⊒↢ߒߥน⢻ᕈ߇ࠆ㧚ᡆૃࡆ࠶࠻⺋ࠅ ࠍ⒁ኒ㎛ߦ↪ࠆ႐ว㧘ㆡಾߥ㊂ߩᡆૃࡆ࠶࠻
⺋ࠅ߇⊒↢ߒߥߣ㧘
2
୯ൻಣℂ߇ਇน⢻ߣߥࠅ⒁ ኒ㎛ࠍ↢ᚑߔࠆߎߣ߇ߢ߈ߥ㧚ߘߎߢ㧘ᡆૃࡆ࠶࠻⺋ࠅࠍ⒁ኒ㎛↢ᚑߦ↪ࠆߚߦߪ㧘㔀㖸ߩᄢ߈ ߐߦࠃࠄߕㆡಾߥ㊂ߩᡆૃࡆ࠶࠻⺋ࠅࠍ⊒↢ߐߖ ࠆᔅⷐ߇ࠆ㧚
⒁ኒ㎛↢ᚑߦ↪ࠆᡆૃࡆ࠶࠻⺋ࠅߩᬌ⸛
ᧄ⺰ᢥߢឭ᩺ߔࠆᡆૃࡆ࠶࠻⺋ࠅߦၮߠߊ⒁ኒ
Received signal
De- modulation
Distortion
Pseudo BER measurement Received
bit sequence
Pseudo error bit sequence De-
modulation
Fig. 3. Measurement of pseudo BER
Fig. 2. Procedure of secret key agreement.
Transmission and reception Station A
Measurement of channel characteristics
Generating a candidate of secret key
Key disagreement correction
Confirmation of key agreement
Secure communication using secret key
Transmission and reception Station B
Measurement of channel characteristics
Generating a candidate of secret key
Key disagreement correction
Confirmation of key agreement
Secure communication using secret key Binarization
Syndrome
hash
Agree/disagree Process of
secret key agreement
Iteration
㎛ᣇᑼߢߪ㧘㔀㖸એᄖߩવㅍ〝ߩഠൻⷐ࿃ߦၮ ߠߡᡆૃࡆ࠶࠻⺋ࠅࠍ⊒↢ߐߖࠆᔅⷐ߇ࠆ㧚ߘ ߎߢ㧘ߎߎߢߪᡆૃࡆ࠶࠻⺋ࠅ⊒↢ᴺߦߟߡᬌ⸛
ߔࠆ㧚
ାภߩ್ቯゲߩ⺋ࠅࠍ↪ߚᣇᴺ
ᡆૃ⺋ࠅࠍ↪ߚࡆ࠶࠻⺋ࠅ₸ផቯᴺ 14-20)ߢߪ㧘 ᄌ⺞ᣇᑼߦ
PSK (Phase Shift Keying)
ࠍ↪ߡ㧘ฃାାภߩᓳ⺞ᤨߩ್ቯゲߦࠝࡈ࠶࠻ࠍਈ߃ࠆᣇ ᴺ߿್ቯゲߦ⋧࿁ォࠍਈ߃ࠆᣇᴺ߇ᬌ⸛ߐࠇߡ
ࠆ㧚
ߎࠇࠄߩ್ቯゲࠍ⺋ࠄߖࠆࠃ߁ߥᣇᴺࠍ↪ߡ㧘 ᡆૃ⺋ࠅࠍ⊒↢ߐߖࠆߣ㧘㔀㖸ߦࠃࠆഠൻࠍ♖ᐲ⦟
ߊផቯߔࠆߎߣ߇น⢻ߢࠆ㧚ߒ߆ߒ㧘ᡆૃࡆ࠶࠻
⺋ࠅߩ⊒↢߇㔀㖸㔚ജߦଐሽߒ㧘㔀㖸㔚ജ߇ዊߐ
ⅣႺߢߪᡆૃ⺋ࠅߩ⊒↢߽ዋߥߊߥࠆߚ⒁ኒ㎛
ߩ↢ᚑߦߪㆡߒߡߥ㧚ߘߎߢ㧘㔀㖸߇ዊߐⅣ Ⴚߢ߽ㆡᐲߦᡆૃࡆ࠶࠻⺋ࠅࠍ⊒↢ߐߖࠆᣇᴺ߇ ᔅⷐߢࠆ㧚
⋧ఘᱡߺࠍ↪ߚᣇᴺ
ߎߎߢߪ㧘
OFDM (Orthogonal Frequency Division Multiplexing)
વㅍ 21) ࠍᗐቯߒ㧘ㅢᏱߣߪ⇣ߥࠆࡄࠗࡠ࠶࠻ࠪࡦࡏ࡞ࠍ↪ߡવㅍ〝ᱡߺߩఘࠍⴕ
㧘ᡆૃࡆ࠶࠻⺋ࠅࠍ⊒↢ߐߖࠆᣇᴺߦߟߡㅀߴ ࠆ㧚
ㅢᏱߩ
OFDM
ࠪࠬ࠹ࡓߢߪ㧘ฦࠨࡉࠠࡖࠕߩ࠺࠲ࠪࡦࡏ࡞ߩవ㗡ߦㅍฃାዪߢᣢ⍮ߢࠆࡄ
ࠗ ࡠ ࠶ ࠻ ࠪ ࡦ ࡏ ࡞ ࠍ ઃ ട ߒ ߡ ߅ ߈ 㧘 ฃ ା ߢ
Fig. 4 (a)
ߩࠃ߁ߦ㧘ࡄࠗࡠ࠶࠻ࠪࡦࡏ࡞ߦၮߠߡવㅍᱡߺࠍផቯఘߒߡࠆ㧚
ߎߎߢ㧘ฦࠨࡉࠠࡖࠕߩᵄᢙࠍ f㧘ㅍାᖱႎ
ࠍs ( f )㧘વ៝〝․ᕈࠍh ( f )㧘㔀㖸ࠍn ( f ) ߣߔࠆ
ߣ㧘ฃାߢߩ
OFDM
ߦ߅ߌࠆฃାାภr ( f ) ߪ㧘)
( ) ( ) ( )
( f h f s f n f
r (1)
ߣߥࠆ㧚ߎߩାภߦኻߒߡ
Fig. 4 (a)
ߩࠃ߁ߥㅢᏱ ߩᣇᴺߢવㅍ〝ᱡߺߩఘࠍⴕ߁ߣ㧘ఘᓟߩାภ y ( f ) ߪ㧘) ( ) ( ) ( )
( f s f n f h f
y (2)
ߣߥࠆ㧚ㅢᏱߢߪ㧘ߎࠇࠍᓳ⺞ߔࠆߎߣߢᖱႎࠍᓧ ࠆߎߣ߇ߢ߈ࠆ㧚
ߎߩવㅍ〝ᱡߺߩఘߩ㓙ߦ㧘⺋ߞߚࡄࠗࡠ࠶࠻
ࠪࡦࡏ࡞ࠍ↪ߡᱡߺఘࠍⴕ߁ߣ㧘ᡆૃ⺋ࠅࠍ⊒
↢ߐߖࠆߎߣ߇น⢻ߢࠆ㧚⺋ߞߚࡄࠗࡠ࠶࠻ࠪࡦ ࡏ࡞ࠍ↪ߡ⋧ఘࠍⴕ߁ᣇᴺߩ৻ߣߒߡ㧘
Fig. 4 (b)
ߩࠃ߁ߦOFDM
ߩోࠨࡉࠠࡖࠕߩ࠺࠲ࠪࡦࡏ࡞ࠍ㧘ਛᔃᵄᢙfcߩࠨࡉࠠࡖࠕߩࡄࠗ
ࡠ࠶࠻ࠪࡦࡏ࡞ࠍ↪ߡᱡߺఘࠍⴕ߁ᡆૃࡆ࠶
࠻⺋ࠅ⊒↢ᴺࠍឭ᩺ߔࠆ㧚ߎߩᣇᴺࠍ↪ߚ႐ว㧘 ᑼ
(1)
ߩฃାାภߦኻߒߡ㧘) ( ) ( ) ( ) ( ) ( )
(
c ce
f h f h f s f n f h f
y (3)
ߣ߁ᱡߺఘࠍⴕ߁ߎߣߦߥࠅ㧘ᡆૃࡆ࠶࠻⺋ࠅ
₸ߦh ( f ) / h ( fc
)
ߩᓇ㗀ࠍᤋߔࠆߎߣ߇ߢ߈ࠆ㧚(a) Regular phase compensation.
(b) Phase compensation for occurrence of pseudo BER.
Fig. 4. Phase compensation using pilot symbol.
Pilot symbol Data symbol
Phase compensation
Frequency (Sub carrier)
Time
Pilot symbol Data symbol
Center frequency ( fc)
Phase compensation
Frequency (Sub carrier)
Time
ᧄ⺰ᢥߢߪ㧘એ㒠ߪਛᔃᵄᢙߢᱡߺఘࠍⴕߞ ߡ⊒↢ߐߖࠆᡆૃࡆ࠶࠻⺋ࠅࠍ↪ࠆ㧚
⸘▚ᯏࠪࡒࡘ࡚ࠪࡦ ࠪࡒࡘ࡚ࠪࡦ⻉ర
ឭ᩺ᣇᑼߩലᕈࠍ⏕ߔࠆߚ㧘ή✢
LAN
ߩࠪࠬ࠹ࡓࠍᗐቯߒ㧘ࠪࡒࡘ࡚ࠪࡦࠍⴕ߁㧚
ࠪࡒࡘ࡚ࠪࡦߢ↪ࠆࡄࡔ࠲ࠍ
Table 1
ߦ␜ߔ㧚વ៝ⅣႺߪ┵ᧃ⥄߇ࠁߞߊࠅߣ⒖േߔ ࠆ㧘ࠆߪ࿐ߩੱ߿߽ߩߩ⒖േߦࠃࠅ㧘Ᏹߦ વ៝ⅣႺ߇ᄌേߔࠆߎߣࠍᗐቯߔࠆ㧚Table 1
ߦ␜ߔࠃ߁ߦ㧘ᗐቯⅣႺߦ߅ߌࠆㆃᑧᵄߩㆃᑧᤨ㑆ߪ
0.1Ps
ೞߺߢ㧘ߘࠇߙࠇ⋧ኻ㔚ജ߇0dB
㧘-5dB
㧘-10dB
ߩ3
ࡄࠬࡕ࠺࡞ߣߒ㧘ฦࡄࠬߪߦ⁛┙ߥࠗࡈࠚࠫࡦࠣ㧘ࠆߪ㧘ࠗࠬࡈࠚࠫࡦ
ࠣߣߔࠆ㧚߹ߚ㧘ᦨᄢ࠼࠶ࡊᵄᢙߩᮡḰ୯ ࠍ
10Hz
ߣߔࠆ߇㧘ߎࠇࠍᄌൻߐߖࠆ႐วߦߟߡ߽ᬌ⸛ߔࠆ㧚
ࡄࠤ࠶࠻᭴ᚑߣ࠲ࠗࡓ࠴ࡖ࠻ߪ
Fig. 5
ߦ␜ߔ߽ߩࠍᗐቯߔࠆ㧚
Fig. 5
߅ࠃ߮Table 1
ߦ␜ߔࠃ߁ߦ㧘 ㅍାߔࠆࡄࠤ࠶࠻ߪࡄࠤ࠶࠻㐳߇400Ps
ߢ㧘ߘࠇߙࠇ
1ms
㑆㓒ߢㅍฃାࠍⴕ߁߽ߩߣߔࠆ㧚ฦࡄࠤ࠶࠻ߪ㧘ࠪࡦࡏ࡞ᦼ߇
4Ps
ߩOFDM
ࠪࡦࡏ࡞ߢ㧘ࡄࠗࡠ࠶࠻ࠪࡦࡏ࡞
20
ࠪࡦࡏ࡞(80Ps)
ߣ㧘80
ࠪࡦ ࡏ࡞ߩ࠺࠲ࠪࡦࡏ࡞ (320Ps) ߆ࠄ᭴ᚑߐࠇࠆߣ ߔࠆ㧚߹ߚ㧘ߘࠇߙࠇߩዪߢ᷹ቯ↪ାภߩㅍฃାࠍ ⴕߞߚᓟ㧘 ᣇߩ࡙ࠩߢ᷹ቯᤨ㑆Ꮕࠍఘߔࠆߚߩ㑆↪ߩࡄࠤ࠶࠻ߩㅍฃାࠍⴕ߁㧚ߎߩ㑆↪
ߩࡄࠤ࠶࠻ࠍฃାߒߚ࡙ࠩߪ㧘ᦨೋߦฃାߒߚࡄ ࠤ࠶࠻ߣ㑆↪ߩࡄࠤ࠶࠻ࠍ↪ߡ✢ᒻ㑆ࠍⴕ
㧘᷹ቯᤨ㑆Ꮕߩᓇ㗀ࠍᛥ߃ࠆ㧚
᷹ቯ↪ାภ߅ࠃ߮㑆↪ࡄࠤ࠶࠻ߩㅍฃା߅ࠃ
߮વ៝〝․ᕈ᷹ቯಣℂߪT 㑆㓒ߢ
138
࿁➅ࠅߒ ⴕ㧘ᱜⷙዪߢߘࠇߙࠇ138
ߩᡆૃࡆ࠶࠻⺋ࠅ₸♽ࠍᓧࠆ㧚ߎߩᡆૃࡆ࠶࠻⺋ࠅ₸♽ߩਛᄩ୯ࠍ 㑣୯ߣߒߡ
2
୯ൻಣℂࠍⴕ㧘⒁ኒ㎛ࠍ↢ᚑߔ ࠆ㧚↢ᚑߒߚ㎛♽ߩ߁ߜ㧘㑣୯ઃㄭߩᡆૃࡆ࠶࠻⺋ࠅ₸ࠍ
2
୯ൻߒߚࡆ࠶࠻ߦߪ㧘Ყセ⊛ᄙߊߩ㎛ਇ৻⥌߇⊒↢ߔࠆ㧚ߘߎߢ㧘㑣୯ઃㄭߦᒰߔࠆ ࡆ࠶࠻ࠍ
10
ࡆ࠶࠻ขࠅ㒰߈㧘ᦨ⚳⊛ߦ128
ࡆ࠶࠻ߩ㎛ࠍ↢ᚑߔࠆ㧚
Table 1. Simulation parameters.
Modulation
OFDM
QPSK (Q
uadratureP
haseS
hiftK
eying) Number of subcarriers: 48
Interval of OFDM symbol: 4ȝs Guard Interval: 0.8ȝs
Channel model
3-path Rayleigh model Independent Rayleigh fading Delay time difference : 0.1ȝs Relative power: 0dB, -5dB, -10dB Maximum Doppler frequency: 10Hz
(nominal value) 3-path Rice model
Independent Rice fading (rice factor: 10dB)
Delay time difference : 0.1ȝs Relative power: 0dB, -5dB, -10dB Maximum Doppler frequency: 10Hz
(nominal value)
Packet format
Length of a packet: 400ȝs Interval of a pair of packet: 2.8ms Measurement time difference: 1.4ms
(Correction by linear interpolation using compensation packet) Generation of key Binary digitization
by threshold of median value Correction of key
disagreement
Error correction within 5 bits by algebraic decoding method Fig. 5. Timing diagram and configuration of data
packet.
T
(1) (2) (3) (137) (138)
3.2ms
400ȝs
Interval of pair of packets 2.8ms
1ms 1ms
Interpolation by 2 packets
GI PILOT DATA DATA
Pilot symbol 20 symbol (80ȝs)
Data symbol 80 symbol (320ȝs) Data packet
(400ȝs) Authorized
User A Authorized User B
time time
time time
OFDM symbols
GI GI
400ȝs
400ȝs
ᡆૃࡆ࠶࠻⺋ࠅ₸ߣ⒁ኒ㎛ߩ↢ᚑ
ߎߎߢߪ㧘ᡆૃࡆ࠶࠻⺋ࠅߩ․ᕈߣ㧘ᡆૃࡆ࠶࠻
⺋ࠅ߆ࠄ↢ᚑߒߚ⒁ኒ㎛ߩ৻ࠍ␜ߔ㧚
߹ߕ㧘㔀㖸߇⊒↢ߒߥⅣႺߦ߅ߡ㧘᷹ቯ↪ା
ภߩㅍฃାࠍⴕ߁ߎߣࠍᗐቯߔࠆ㧚᷹ቯ↪ାภࠍฃ
ାߒߚᱜⷙዪߪ㧘ฃାାภߦᡆૃࡆ࠶࠻⺋ࠅࠍ⊒↢
ߐߖ㧘ࡄࠤ࠶࠻ߏߣᡆૃࡆ࠶࠻⺋ࠅ₸ࠍ⸘▚ߒ㧘ߘ ߩ♽߆ࠄ㎛ࠍ↢ᚑߔࠆ㧚ᡆૃࡆ࠶࠻⺋ࠅߩ⊒
↢ߦ߅ߡ㧘1ࡄࠤ࠶࠻ߚࠅߩᡆૃࡆ࠶࠻⺋ࠅ₸
ࠍ
0.1
ಾࠅߢಽ㘃ߒ㧘ߘࠇߙࠇߩ㗔ၞߩ⊒↢⏕₸ࠍ᳞ߚಽᏓ․ᕈࠍ
Fig. 6 ߦ␜ߔ㧚Fig. 6
ࠃࠅ㧘1 ࡄࠤ࠶࠻ߚࠅߩᡆૃࡆ࠶࠻⺋ࠅ₸߇0
㨪0.1
ߢࠆ႐ว߇ᦨ߽ᄙߊ⊒↢ߒߡ߅ࠅ㧘
0.35
⒟ᐲߢࠆߎ ߣ߇ࠊ߆ࠆ㧚ߒ߆ߒ㧘0.1
એߩᡆૃࡆ࠶࠻⺋ࠅ₸߽
0.65
⒟ᐲ⊒↢ߒߡࠆߎߣ߆ࠄ㧘♽ߪ2
୯ൻ ಣℂ߇น⢻ߢࠆ㧚ᰴߦ㧘⊒↢ߒߚ⺋ࠅ₸߆ࠄ㎛ࠍ↢ᚑߔࠆ৻ࠍ␜
ߔ㧚ࡄࠤ࠶࠻ߏߣߩᡆૃࡆ࠶࠻⺋ࠅ₸ߩᄌേࠍ
Fig. 7
ߦ␜ߔ㧚Fig. 7 ߩᡆૃࡆ࠶࠻⺋ࠅ₸♽ߦኻ
ߒߡ㑣୯㧔♽ߩਛᄩ୯㧕એߣ㑣୯એਅߢ
2
୯ൻ ಣℂࠍⴕ㧘㎛♽ࠍ↢ᚑߔࠆ㧚⒁ኒ㎛ߩ↢ᚑᤨ㑆ߣ⒁ኒ㎛ߩోᕈ
Fig. 5
ߦ␜ߔTߩ୯ᰴ╙ߢߪ㧘㎛ߩ↢ᚑߦ⩨ᄢߥᤨ㑆߇߆߆ࠅ㧘⒁ኒ㎛ߩ↢ᚑല₸߇ૐਅߔࠆ㧚৻ᣇ㧘 Tߩ୯ࠍㆊᐲߦዊߐߊ⸳ቯߔࠆߣ㧘ߘࠇߙࠇߩࡆ࠶
࠻⺋ࠅ₸ߦ⋧㑐㑐ଥ߇↢ߓ㧘↢ᚑߒߚ⒁ኒ㎛ߩࡆ࠶
࠻ߩࡦ࠳ࡓᕈ߇ૐਅߔࠆน⢻ᕈ߇ࠆ㧚ߘߎߢ㧘
↢ᚑߒߚ⒁ኒ㎛ࠍኻ⽎ߣߒߡ㧘ߘߩ㎛ߩ⥄Ꮖ⋧㑐ࠍ
᳞㧘Tߩ⸳ቯ୯ߦߟߡᬌ⸛ߔࠆ㧚
Fig. 8
ߦ㧘Tߩ୯ࠍᄌൻߐߖߡ↢ᚑߒߚ㎛♽ߦኻߒߡ㧘㎛♽ࠍࡆ࠶࠻ߏߣࠬࠗ࠼ߐߖߚ߽ߩߣ ߩ⥄Ꮖ⋧㑐ࠍ⸘▚ߒߚ႐วߩ․ᕈࠍ␜ߔ㧚T ߇
30
ms㨪90ms
ߩ㑆ߪ㧘⥄Ꮖ⋧㑐․ᕈߦ߹ࠅᄌൻ߇ߺࠄࠇߥ㧚৻ᣇ㧘T ࠍ
20 ms
એਅߦ⸳ቯߔࠆߣ㧘㎛
1
ࡆ࠶࠻⒖േߐߖߚ႐วߦ⥄Ꮖ⋧㑐߇0.2
એߦ ߥࠅ㧘㎛♽ߦ⥄Ꮖ⋧㑐߇ࠆߎߣ߇⏕ߢ߈ࠆ㧚㎛♽ߦ⥄Ꮖ⋧㑐߇ࠆ႐วߪ㧘⥄Ꮖ⋧㑐߇ߥ႐ วߦᲧߴߡ㧘⋑⡬ዪߦ߅ߌࠆ⒁ኒ㎛ߩ✚ᒰߚࠅߦࠃ ࠆ⸃⺒߇ኈᤃߦߥࠆน⢻ᕈ߇ࠅ㧘⒁ኒ㎛ߣߒߡᦨ ㆡߢߪߥ㧚ߘߎߢᧄ⺰ᢥߦ߅ߌࠆ㧘એ㒠ߩᬌ⸛ߪ
⥄Ꮖ⋧㑐․ᕈߦᏅ߇ߺࠄࠇߥT = 30 msࠍ↪ࠆ㧚
㔀㖸ߦኻߔࠆ․ᕈ
㔀㖸߇ឭ᩺ᣇᑼࠍ↪ߡ↢ᚑߒߚ⒁ኒ㎛ߩ
ߦ߷ߔᓇ㗀ߦߟߡ⺞ߴࠆߚ㧘㔀㖸ⅣႺࠍᗐቯ ߒ㧘ࠪࡒࡘ࡚ࠪࡦࠍⴕ߁㧚Fig. 9 ߦ㧘ࠗ
Fig. 7. An example of pseudo BER sequence.
Fig.6. Occurrence distribution of BER.
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 0
0.1 0.2 0.3 0.4 0.5
Pseudo BER
Occurrence ratio
0 20 40 60 80 100 120
0 0.2 0.4 0.6 0.8 1
Number of packet
Pseudo BER
Threshold
Fig. 8. Auto correlation of key sequence.
0 1 2 3 4 5 6 7 8 9
-0.2 0.0 0.2 0.4 0.6 0.8 1.0
Delay [bit]
Correlation
䎃
䎃 T=10ms T=20ms T=30ms T=90ms
ࡈࠚࠫࡦࠣⅣႺ㧘߅ࠃ߮㧘ࠗࠬࡈࠚࠫࡦࠣⅣ Ⴚߦ߅ߌࠆ㧘ㅍାାภ㔚ജኻ㔀㖸㔚ജᲧ㧔SN Ყ㧕 ߦኻߔࠆ⒁ኒ㎛৻⥌₸․ᕈࠍ␜ߔ㧚ߥ߅㧘⒁ኒ㎛৻
⥌₸ߪ㧘↢ᚑߒߚ
128
ࡆ࠶࠻ߩ⒁ኒ㎛߇ᱜⷙዪ㑆ߢ ቢోߦ৻⥌ߔࠆഀว㧘ߟ߹ࠅ㧘⒁ኒ㎛ࠍߢ߈ࠆ⏕₸ߢࠆ㧚߹ߚ㧘Fig. 9 ߦߪ㧘ߘࠇߙࠇߩⅣႺߢ
⺋ࠅ⸓ᱜࠍㆡ↪ߔࠆ೨ߣㆡ↪ߒߚᓟߩ․ᕈࠍ␜ߒ ߡࠆ㧚ߎߎߢߩ⺋ࠅ⸓ᱜߪ㧘5bitએౝߩ⺋ࠅ㧔㎛
ਇ৻⥌㧕ߥࠄ⏕ታߦ⸓ᱜߢ߈ࠆߣ߁㧘ℂᗐ⊛ߥ⸓
ᱜࠍⴕ߁߽ߩߣߔࠆ㧚
Fig. 9
ߩࠗࡈࠚࠫࡦࠣⅣႺߣࠗࠬࡈࠚࠫࡦࠣⅣႺߩ⚿ᨐࠃࠅ㧘⺋ࠅ⸓ᱜࠍⴕ߁೨ߩ⁁
ᘒߢߪ㧘↢ᚑߒߚ⒁ኒ㎛߇ᔅߕߒ߽৻⥌ߒߥน⢻
ᕈ߇ࠆߎߣ߇⏕ߢ߈ࠆ㧚ߒ߆ߒ㧘SN Ყ߇⚂
15dB
એߩⅣႺߢߪ㧘⺋ࠅ⸓ᱜࠍⴕ߁ߎߣߢ⒁ኒ㎛ߩ߇น⢻ߢࠆߎߣࠍ␜ߒߡࠆ㧚
ࡈࠚࠫࡦࠣᄌേߦኻߔࠆ․ᕈ
᷹ቯାภߩㅍฃା㑆㓒ߦኻߒߡࡈࠚࠫࡦࠣᄌ
േߩᦼ߇⍴႐ว㧘᷹ቯ↪ାภߩㅍฃାߩㆊ⒟ߢ વ៝〝․ᕈ߇ᄌേߒߡߒ߹߁ߚ㧘ਔዪߩᡆૃࡆ࠶
࠻⺋ࠅ₸߇⇣ߥࠅ⒁ኒ㎛ߩ߇࿎㔍ߦߥࠆߣ⠨
߃ࠄࠇࠆ㧚ߘߎߢࡈࠚࠫࡦࠣᄌേߩᦼ߇⒁ኒ㎛
ߩߦਈ߃ࠆᓇ㗀ߦߟߡᬌ⸛ߔࠆ㧚SN Ყ߇
20dB
ߩⅣႺࠍᗐቯߒ㧘ߘߩⅣႺਅߢߩᦨᄢ࠼࠶ࡊᵄᢙߏߣߩ㎛৻⥌₸․ᕈࠍ
Fig. 10
ߦ␜ߔ㧚 ห࿑ࠃࠅ㧘ࠗࡈࠚࠫࡦࠣ㧘ࠗࠬࡈࠚࠫࡦࠣߩਔᣇߩࡈࠚࠫࡦࠣⅣႺߢ㧘ᦨᄢ࠼࠶ࡊ
ᵄᢙ߇
40 Hz
એਅߩ႐วߦ㧘↢ᚑߒߚ⒁ኒ㎛߇৻⥌ߔࠆߎߣ߇ࠊ߆ࠆ㧚
2.4GHz
Ꮺߩή✢LAN
ࠍᗐ(a) Rayleigh fading environment.
Fig. 9. Key agreement performance when SN ratio is changed.
(b) Rice fading environment.
-10 -50 0 5 10 15 20 25 30 35 40 10
20 30 40 50 60 70 80 90 100
SN ratio [dB]
Key agreement rate [%]
Maximum Doppler frequency:
10Hz
䎃
䎃
w/o correction w correction
-10 -50 0 5 10 15 20 25 30 35 40 10
20 30 40 50 60 70 80 90 100
SN ratio [dB]
Key agreement rate [%]
䎃
䎃 Maximum Doppler frequency:
10Hz
w/o correction w correction
Fig. 10. Key agreement performance when maximum Doppler frequency is changed.
(a) Rayleigh fading environment.
(b) Rice fading environment.
100 101 102 103
0 10 20 30 40 50 60 70 80 90 100
Maximum Doppler frequency [Hz]
Key agreement rate [%]
䎃
䎃 w/o correction
w correction
SN ratio: 20dB
100 101 102 103
0 10 20 30 40 50 60 70 80 90 100
Maximum Doppler frequency [Hz]
Key agreement rate [%]
䎃
䎃 w/o correction
w correction
SN ratio: 20dB
ቯߔࠆ႐วߦ㧘ᦨᄢ࠼࠶ࡊᵄᢙ߇
40 Hz
ߣߥ ࠆߩߪ㧘┵ᧃߥߤߩ⒖േㅦᐲ߇⚂5 m/s
ߩ႐วߢࠆ㧚ή✢
LAN
ߢߪ㧘┵ᧃߩ⒖േㅦᐲ߇5 m/s
ߣߥ ࠆߎߣࠍᗐቯߒߚ⸳⸘߇ߥߐࠇߡߥߚ㧘ឭ᩺ᣇᑼߦࠃࠆ⒁ኒ㎛ߪലߢࠆߣ߃ࠆ㧚
߹ߣ
ᧄ⺰ᢥߢߪ㧘㔚ᵄࠍ↪ߚ⒁ኒ㎛ᣇᑼߦ߅
ߡ㧘ੱὑ⊛ߦᡆૃࡆ࠶࠻⺋ࠅࠍ⊒↢ߐߖ㧘ߘߩᡆૃ
ࡆ࠶࠻⺋ࠅ₸ࠍ↪ߡ⒁ኒ㎛ࠍ↢ᚑߒߔࠆᣇ ᑼࠍឭ᩺ߒߚ㧚
ᧄ⺰ᢥߢߪ㧘߹ߕ⒁ኒ㎛↢ᚑ߇น⢻ߣߥࠆᡆૃࡆ
࠶࠻⺋ࠅߩ⊒↢ᣇᴺߦߟߡᬌ⸛ߒߚ㧚ᡆૃࡆ࠶࠻
⺋ࠅࠍ⒁ኒ㎛ᣇᑼߦㆡ↪ߔࠆߦߪ㧘㔀㖸ߦࠃࠆ ഠൻએᄖߩഠൻⷐ࿃ࠍᡆૃࡆ࠶࠻⺋ࠅߦᤋߐߖ ࠆߎߣ߇ᔅⷐߢࠆ㧚ߘߎߢᧄ⺰ᢥߢߪ㧘
OFDM
વ ㅍߦ߅ߡ㧘ਛᔃᵄᢙߩࠨࡉࠠࡖࠕߩࡄࠗࡠ࠶࠻ࠪࡦࡏ࡞ࠍ↪ߡ㧘ઁߩࠨࡉࠠࡖࠕߩᱡߺఘ ࠍⴕ߁ᣇᴺࠍណ↪ߒߚ㧚
ឭ᩺ᣇᑼߦߟߡ㧘ή✢
LAN
ⅣႺࠍᗐቯߒߚࠪࡒࡘ࡚ࠪࡦࠍⴕߞߚߣߎࠈ㧘ࠗࡈࠚࠫ
ࡦࠣ㧘߅ࠃ߮㧘ࠗࠬࡈࠚࠫࡦࠣⅣႺਅߢ
SN
Ყ߇
15 dB
એਅ㧘ᦨᄢ࠼࠶ࡊᵄᢙ߇40Hz
એਅߣ߁ⅣႺߦ߅ߡ⒁ኒ㎛߇น⢻ߢࠆߎߣ ࠍ␜ߒߚ㧚
ෳ⠨ᢥ₂
1) ═ේᱜ㓶, Ⴚ㓉৻㧘ᥧภ㧘㧔┙ 㧘᧲੩㧘2000㧕㧚 2) ጟᧄ㦖㧘ጊᧄඳ⾗㧘ઍᥧภ㧘㧔↥ᬺ࿑ᦠ㧘᧲੩㧘
1979㧕㧚
3) J. E. Hershey, A. A. Hassan and R. Yarlagadda,
“Unconventional cryptographic keying variable management,” IEEE Trans. Commun., vol. 43, pp. 1-6 (1995).
4) A. Hassan, W. E. Stark, J. E. Hershey and S.
Chennakeshu, “Cryptographic key agreement for mobile radio,” Digital Signal Processing, vol. 6, pp. 207-212 (1996).
5) ጤ⺈ੱ㧘╣ጟ⑲৻㧘̌㔚ᵄવ៝․ᕈࠍᵴ↪ߒߚ⒁ ኒᖱႎߩવㅍᛛⴚ㧘̍ାቇ⺰(B)㧘vol.J90-B㧘 no.9㧘pp.770-783 (2007)㧚
6) ർᶆੱ㧘╣ጟ⑲৻㧘̌㒽⒖േㅢାߦ߅ߌࠆOFDM ߩવㅍ〝․ᕈߦၮߠߊ⒁ኒ㎛ᣇᑼ㧘̍ାቇ⺰
(A) 㧘vol. J87-A㧘no.10㧘pp.1320-1328 (2004) 㧚 7) T. Aono, K. Higuchi, T. Ohira, B. Komiyama, and H.
Sasaoka, “Wireless secret key generation exploiting reactance-domain scalar response of multipath fading channels,” IEEE Trans. Antennas Propag., vol. 53, No.
11, pp. 3776-3784 (2005).
8) W.C. Jakes, Microwave mobile communications, John Wiley & Sons (1974).
9) ໊ᴛᅢ↵㧘࠺ࠖࠫ࠲࡞⒖േㅢାߩ㔚ᵄવ៝ၮ␆㧘㧔ࠦ
ࡠ࠽␠㧘᧲੩㧘2003㧕㧚
10) ᄢᐔቁ㧘㘵⨲ᕶ৻㧘̌㔚ሶᩏዉᵄེࠕࠕࡦ࠹
࠽̍㧘ାቇ⺰(C)㧘Vol.J87-C㧘no.1㧘pp.12-31 (2004)㧚 11) ᷡ᳓ፏਯ㧘ጤ⺈ੱ㧘╣ጟ⑲৻㧘̌ࠛࠬࡄࠕࡦ࠹࠽
ࠍ↪ߚ⒁ኒ㎛ᣇᑼߦ߅ߌࠆ⋑⡬⠴ᕈะߩ ᬌ⸛㧘̍ାቇᛛႎ㧘AP2008-43㧘pp.41-46 (2008)㧚 12) Ꮉବ৻㧘ᷡ᳓ፏਯ㧘ጤ⺈ੱ㧘╣ጟ⑲৻㧘̌ࠛࠬ
ࡄࠕࡦ࠹࠽ࠍ↪ߚ⒁ኒ㎛ᣇᑼߦ߅ߌࠆ⋑⡬
⠴ᕈะߩᬌ⸛㧘̍ାቇᛛႎ㧘RCS2009-34㧘pp.37-42 (2009)㧚
13) T. Kitano, A. Kitaura, H. Iwai, H. Sasaoka, “A Private key agreement scheme based on fluctuations of BER in wireless communications,” Proc. ICACT 2007, 8B, pp.1495-1499 (2007).
14) D. J. Gooding, “Performance monitor techniques for digital receivers based on extrapolation of error rate,”
IEEE Trans. Commun. Technol., vol.COM-16, pp.380-387 (1968).
15) S. Takenaka, T. Katoh, “Bit error monitor for four phase PSK system,” ICC'80 Conference record, pp.251-256 (1980).
16) E. A. Newcombe, S. Pasupathy, “Error rate monitoring for digital communication,” Proceedings of IEEE, vol.70, no.8, pp.805-828 (1982).
17) I. M. Kostiü, “Pseudo error rate of a PSK system with hardware imperfections, noise and cochannel interference,” IEE Proceedings, vol.136, Pt. I , no.5, pp.333-338 (1989) .
18) J. M. Keelty, “On-line pseudo-error monitors for digital transmission systems,” IEEE Trans. Commun., vol.26, no.8, pp.1275-1282 (1978).
19) ጤ⺈ੱ㧘ᷰㆻ⾆ᔒ㧘㜞ାੱ㧘╣ጟ⑲৻㧘̌ᡆૃ
⺋ࠅߦၮߠߊࡆ࠶࠻⺋ࠅ₸ߩផቯᴺ㧘̍ାቇᛛႎ㧘 AP2006-15㧘pp.35-40 (2006)㧚
20) ⍹ፒବテ㧘ጤ⺈ੱ㧘╣ጟ⑲৻㧘̌ᡆૃ⺋ࠅߦၮߠ ߊࡆ࠶࠻⺋ࠅ₸ផቯᴺߩ㜞♖ᐲൻߦ㑐ߔࠆᬌ⸛㧘̍
หᔒ␠ᄢቇℂᎿቇ⎇ⓥႎ๔㧘49㧘pp. 100-107 (2008)㧚 21) દਤ⺈㧘OFDM ᄌ⺞ᛛⴚ㧘㧔࠻ࠤ࠶ࡊࠬ㧘᧲੩㧘
2000㧕㧚
