第12回カーネル/VM探検隊

Transcript

1. ϥδΦ͸Α͘Θ͔Γ·ͤΜ͕ɺετϨʔτํࣜΑΓεʔύʔϔ
   ςϩμΠϯํࣜͷ΄͏͕Α͍ͱࢲ͸ࢥ͍·͢ɻ
   XXXX
   Oct 8th, 2016
   1 / 18
   

   View Slide

2. CAUTION
   ແઢ๣ड಺༰ͷୈࡾऀ΁ͷ࿙Ӯɼ઄༻͸೔ຊࠃ๏཯ɼి೾๏ୈ 59 ৚ɼୈ
   109 ৚ʹΑΓܐࣄേ෇Ͱېࢭ͞Ε͍ͯ·͢
   ແ໔ڐແઢہʹΑΔ (ಛఆͷແઢҎ֎ͷ) ૹ৴͸ి೾๏ୈ 4 ৚ͷෆ๏ແ
   ઢہʹ͋ͨΓɼേͤΒΕ·͢
   ͜͜Ͱ͍͏ແઢہͱ͸ϒϩʔυόϯυ์ૹͷϥδΦɼςϨϏͷૹ৴ࢪઃͩ
   ͚Ͱͳ͘ɼి೾๏ୈ 2 ৚ୈ 5 ߸Ͱఆٛ͞ΕΔʮແઢઃඋٴͼແઢઃඋͷ
   ૢ࡞Λߦ͏ऀͷ૯ମʯΛࢦ͠·͢
   2 / 18
   

   View Slide

3. ϥδΦͷ࢓૊Έ
   ߭ੴϥδΦ
   ৼ෯มௐͷ৔߹
   同調回路
   検波器
   ローパス
   イヤホン
   アンテナ
   3 / 18
   

   View Slide

4. ৼ෯มௐ೾ͷݕ೾
   4 / 18
   

   View Slide

5. ಉௐճ࿏
   ω0 =
   1
   √
   LC
   , f0 =
   1
   2π
   √
   LC
   ΠϯμΫλ͸ిྲྀͷมԽʹΑͬͯىిྗ͕ൃੜ
   ίϯσϯα͸ిѹͷมԽʹΑͬͯిՙ͕มԽ
   VL(t) = L
   diL
   dt
   , iC(t) = C
   dVC
   dt
   ฒྻճ࿏Ͱ͸ɼ֤ૉࢠʹ͔͔Δిѹ͸౳͍͠
   VL = VC
   ిؾճ࿏Ͱ͸ɼશͯͷૉࢠʹྲྀΕΔిྲྀͷ࿨͕ྵʹͳ
   Δ iC + iL = 0
   d2i(t)
   dt2
   +
   1
   LC
   i(t) = 0
   同調回路
   5 / 18
   

   View Slide

6. ݕ೾ճ࿏
   ৴߸͔ΒแབྷઢΛͱΓͩ͢
   ߭ੴ΍μΠΦʔυ͕ϑΟϧλͱͳͬ
   ͍ͯΔ
   ࣮͸ḊͼͨΧϛιϦͷਕͱΤϯϐπ
   ͷਊͰ΋ΠέΔ
   ͍ΘΏΔ foxhole radioʢᆠߺϥ
   δΦʣ
   import numpy as np
   from scipy.signal import hilbert
   t = np.linspace(0,1,2048)
   E0 = 1
   fc = 20
   phi_c = 0
   fm = 2
   m = 0.9
   phi_m = 0
   E = E0*np.cos(fc*2*np.pi*t + phi_c)
   x = m*np.sin(fm*2*np.pi*t + phi_m)
   E_m = E0*np.cos(fc*2*np.pi*t + phi_c) \
   *(1 - (m/2)*(1-np.sin(fm*2*np.pi*t+phi_m)
   signal = hilbert(E_m)
   envelope = np.abs(signal)
   6 / 18
   

   View Slide

7. ΞφϩάϥδΦͷมભ
   ߭ੴϥδΦ
   ਅۭ؅ϥδΦʢฒࡾɼฒ࢛ɼߴҰͳͲʣ
   ࠷ॳ͸ग़ྗΛೖྗʹ໭͢ਖ਼ؼؐʹΑΔ૿෯͚ͩ
   εʔύʔϔςϩμΠϯ
   http://www.marutsu.co.jp/wp/datatech/4562/
   7 / 18
   

   View Slide

8. ϥδΦࠓੲ
   ͖͞΄Ͳ·Ͱ͸ɼੲͷ࿩
   ΞφϩάϥδΦͩͱ৭ʑ໘౗
   ૿෯ͱ͔νϡʔχϯάͱ͔ग़ྗஈͷՃ޻ͱ͔
   ΈΜͳେ޷͖ DSP ͱμΠϨΫτίϯόʔδϣϯड৴
   εʔύʔϔςϩμΠϯͷ IF Λ 0Hz ʹͨ͠ߏ଄
   8 / 18
   

   View Slide

9. DSP ϥδΦ
   TV Ͱ΋ϥδΦͰ΋ಉ͡ɽ࣮͸ܞଳి࿩Ͱ΋ಉ͡
   ৴߸Λ A/D ม׵͠ɼίϯϐϡʔλʹऔΓࠐΉ͚ͩ
   ͜ͷਤ͸νϡʔφʔνοϓͷ R820T ͷσʔλγʔτΑΓ
   9 / 18
   

   View Slide

10. I/Q ৴߸
    ೖྗͷ RF ʹɼہ෦ൃৼث͔Β 90 ౓ͦΕͧΕҐ૬͕ҟͳΔ΋ͷΛՃ͑Δ
    In-phase ৴߸
    Quadrature-phase ৴߸
    νϡʔφʔνοϓ͸ I/Q ৴߸ʢϕʔεόϯυ৴߸ʣΛಘΔ
    10 / 18
    

    View Slide

11. RTL2832U
    ΈΜͳେ޷͖ֈνοϓʂ
    ޿Ҭଳͷड৴͕Մೳʂ
    Ξοϓίϯόʔτճ࿏Λ௥Ճͨ͠Β GPS ৴߸΋ड৴Մೳ
    ͍͍ͩͨ 1 GHz ͙Β͍·Ͱड৴Մೳ
    11 / 18
    

    View Slide

12. RTL2832U
    12 / 18
    

    View Slide

13. RTL2832U
    13 / 18
    

    View Slide

14. ͱ͜Ζ͜ͷ USB υϯάϧͬͯ
    ͦ͏Ͱ͢ɼϫϯηά TV ड৴༻
    ͳΜͱळ༿ݪͰ 500 ԁͰߪೖ
    Ξϯςφ͸ΞϚνϡΞແઢͷ 144/430 MHz ༻Ͱɼ3000 ԁ͙Β͍
    SDRʢSoftware-difined Radioʣ
    14 / 18
    

    View Slide

15. ͔͍͔ͭͨʂ
    RTL-SDR υϥΠόΛಋೖ
    ͋ͱ͸৭ʑௌ͚ͩ͘ʂ
    15 / 18
    

    View Slide

16. ADS-B
    16 / 18
    

    View Slide

17. GqrxʢGNU Radioʣ
    17 / 18
    

    View Slide

18. ·ͱΊ
    ੲ͸ϥδΦ޻࡞͕ిࢠ޻࡞ͷೖ໳ʹΑ͘࢖ΘΕ͍ͯͨ
    ϥδΦ͔ΒΈΜͳ͕཭Ε͍ͯͬͯٱ͍͠
    SDR ͰϥδΦΛௌ͘ͷ΋ྑ͍ͷͰͳ͍͔
    Raspberry Pi ʹࢗ͠ͱ͍ͯϑϥΠτϨʔμʔ࡞Δͱ͔΋؆୯
    radiko ϞυΩΛՈʹ࡞Δͷ΋Մೳ
    ͍Ζ͍Ζ༡ΜͰΈΑ͏ʂ
    18 / 18
    

    View Slide