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Ide dasar metode enkripsi untuk sistem MIMO-OFDM pada lapisan fisik

Saya mencoba menjelaskan topiknya dengan istilah sederhana. Bagi saya, untuk memahami materi ini, pengetahuan khusus tidak diperlukan, kecuali kemampuan membaca teks dalam bahasa Rusia dan sedikit pengetahuan matematika. Mungkin di suatu tempat saya melewatkan detail penting atau memberi tahu hal-hal yang terlalu jelas, tetapi ini semua demi ketersediaan umum. Jangan menilai dengan ketat. Selamat membaca.





Mengapa ini sangat penting?

, , ( , ). , . 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) <θ (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} {γ_ {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_ {batal}] ^ T

, : , .





Ω ^ l_ {batal} = ({H ^ l} ​​_ {batal}) ^ {- 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





[] - Skema beamforming dan jamming kooperatif berbasis MIMO virtual untuk keamanan jaringan sensor nirkabel berkerumun





[] - Otentikasi Lapisan Fisik melalui MIMO Fading Wiretap Channels





[] - Skema beamforming dan jamming kooperatif berbasis MIMO virtual untuk keamanan jaringan sensor nirkabel berkerumun







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