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Grundlegende Ideen fĂŒr VerschlĂŒsselungsmethoden fĂŒr MIMO-OFDM-Systeme auf der physischen Ebene

Ich habe versucht, das Thema in einfacher Sprache zu erklĂ€ren. Es scheint mir, dass zum VerstĂ€ndnis dieses Materials keine besonderen Kenntnisse erforderlich sind, außer der FĂ€higkeit, Texte auf Russisch zu lesen und ein wenig Mathematik zu beherrschen. Vielleicht habe ich irgendwo wichtige Details ĂŒbersehen oder zu offensichtliche Dinge erzĂ€hlt, aber das ist alles aus GrĂŒnden der allgemeinen VerfĂŒgbarkeit. Beurteilen Sie nicht streng. Fröhliches Lesen.





Warum ist es so wichtig?

, , ( , ). , . OFDM ( , ), . – , – MIMO .





, . , .








. OFDM- MIMO massive-MIMO , .





MIMO massive-MIMO ?

MIMO (Multiple Input Multiple Output) – , . :





  • SISO - Single Input Single Output





  • SIMO - Single Input Multiple Output





  • MISO - Multiple Input Single Output





  • MIMO - Multiple Input Multiple Output





, SIMO – , , . , 1000 , 5000 . , - . , MIMO , , - - .





MIMO , . , . ( ). , , , . MIMO , .





:





  • (time diversity) – .





  • (frequency diversity) – , .





  • (spatial diversity) – ( ) , , .





Y – , H – , X – , N – (AWGN- ). :





Y = HX + N.

– – :





X ^ * = (H ^ TH- \ sigma ^ 2I) ^ {- 1} H ^ TY





, .





Massive-MIMO – , . 128, 256
 , 2-3 . MIMO WiFi, LTE. Massive-MIMO 5G , , 6G.





. MIMO , , . , ( ).





MIMO-system OFDM .

OFDM (orthogonal frequency-division multiplexing — ) – , , . .





- OFDM- : (ISI – inter-symbol interference) (ICI – inter-carrier interference).





ISI 





, , . , (guard interval).





ICI





, , . – . (CP insertion) – , , ISI, .





OFDM:









  • ( ( ), )





  • ( )





OFDM:





  • , -













, . , .





: , (CIA triangle - Confidentiality, Integrity, Availability). .





.





, . , , . :





  • .





  • – . , , .





  • (, ), , .





.





, . : , , , .





.





. , , . - DOS (Denial of Service) DDOS (Distributed Denial of Service) . .





, ( ) . . MIMO-OFDM .





, . .





: Fake client attack (FCA) Fake access point (AP) attack. 





Fake client attack. (CSI – Channel State Information). .





Fake access point attack. , - . .





. .





, . , , , .





:





  • H0 = " " H1 = " "





  • ,





  • , .





AKBA(asymmetric-key based authentication):





  • , .





h_n (t) = αh_n (t - 1) + \ sqrt {1-α ^ 2} z_n (t)

α - , z(t) - c.. .





  • , b.





  • b, - (K1, K2)





  • K1, K2, .





SKBA(symmetric-key based authentication):





  • , .





h_n (t) = αh_n (t - 1) + \ sqrt {1-α ^ 2} z_n (t)

  • . , .





  • 2N





c ^ * = argmin_ {c∈C} || h_A (2) - c || ^ 2

  • .





e = h_A (2) - c ^ *





h_B = h_B (1) - e

  • .





c ^ * = argmin_ {c∈C} || h_B - c || ^ 2

  • - , .









( , ). ( MIMO-OFDM ) . , .





.





PLA(Physical Layer Authentication)





  • , ( ).





  • t > 1 , :





ψ (t) = \ frac {1} {N {\ gamma_ {A}} ^ 2 (t)} \ sum_ {n = 1} ^ {N} {| h_n (t) -α ^ {t-1} h_n (1) | ^ 2}

  • :





ψ (t) <Ξ (t)

, , . , .









, , .





: , , .





, . 4 . ( ) , , , ( , ). , .









. , .









. , ( - ). . :





Y = HSX + N.

N - AWGN( ), H - , X -





:





X ^ * = S ^ {- 1} H ^ {- 1} Y = X + S ^ {- 1} H ^ {- 1} N.

. , , . .













, M .





M w . M





x = \ sum_ {i = 1} ^ {M} {w_ms_i}

(SINR - signal-to-interference-plus-noise ratio)





\ gamma_ {k, m} = \ frac {P | h_kw_m | ^ 2} {\ sum_ {i = 1, i \ neq m} ^ {M} {P | h_kw_i | ^ 2} + \ sigma ^ 2}

P -





:





w_ {m_k} = arg max_ {1 ≀ m ≀ M} {Îł_ {k, m}}

  , SINR SINR. , SINR. .





.









: . . , .





(AN - Artificial Noise)





. , , .





l- :





x ^ l_ {AN} = Ω ^ l_ {ZF} u ^ l + Z ^ lv ^ lΩ ^ l_ {ZF} = (H ^ l) ^ {+}

Z SVD :





H ^ l = U ^ l Λ ^ l [V ^ l Z ^ l] ^ H.

:





y ^ l = H ^ lx ^ l + n ^ l = u ^ l + H ^ ln ^ l

:





y ^ l_ {AN} = G ^ lx ^ l_ {AN} + n ^ l = G ^ l Ω ^ l_ {ZF} u ^ l + G ^ l Z ^ lv ^ l + n ^ l

(AFF - Artificial Fast Fading)





. . , .





l- :





x ^ l_ {AFF} = Ω ^ l_ {AFF} u ^ lΩ ^ l_ {AFF} = [Ω ^ l_ {rand} Ω ^ l_ {Abbrechen}] ^ T.

, : , .





Ω ^ l_ {cancel} = ({H ^ l} ​​_ {cancel}) ^ {- 1} (I - {H ^ l} ​​_ {rand} {Ω ^ l} ​​_ {rand})

:





y ^ l_ {AFF} = H ^ lx ^ l_ {AFF} + n ^ l = u ^ l + n ^ l

:





y ^ l_ {AFF} = G ^ lx ^ l_ {AFF} + n ^ l = G ^ l Ω ^ l_ {AFF} u ^ l + n ^ l









, , . , ( ), 
 . , .









. , . , . , , .





, .





. , . .





:

[] - What is Information Security? The Basics of Information Security





[] - Comparison Between Asymmetric and Symmetric Channel-Based Authentication for MIMO Systems





[] - A Physical Layer Security Scheme Employing Imaginary Receiver for Multiuser MIMO-OFDM Systems





[] - High security orthogonal factorized channel scrambling scheme with location information embedded for MIMO-based VLC system





[] - Mode Selection in MU-MIMO Downlink Networks: A Physical-Layer Security Perspective





[] - Virtuelles MIMO-basiertes kooperatives Beamforming- und Jamming-Schema fĂŒr die Sicherheit von drahtlosen Cluster-Sensornetzwerken





[] - Physical Layer Authentication ĂŒber MIMO Fading Wiretap Channels





[] - Virtuelles MIMO-basiertes kooperatives Beamforming- und Jamming-Schema fĂŒr die Sicherheit von drahtlosen Cluster-Sensornetzwerken







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