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第12回カーネル/VM探検隊
orumin
October 08, 2016
Technology
0
230
第12回カーネル/VM探検隊
orumin
October 08, 2016
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Transcript
ϥδΦΑ͘Θ͔Γ·ͤΜ͕ɺετϨʔτํࣜΑΓεʔύʔϔ ςϩμΠϯํࣜͷ΄͏͕Α͍ͱࢲࢥ͍·͢ɻ XXXX Oct 8th, 2016 1 / 18
CAUTION ແઢड༰ͷୈࡾऀͷ࿙Ӯɼ༻ຊࠃ๏ɼి๏ୈ 59 ɼୈ 109 ʹΑΓܐࣄേͰېࢭ͞Ε͍ͯ·͢ ແ໔ڐແઢہʹΑΔ (ಛఆͷແઢҎ֎ͷ) ૹ৴ి๏ୈ 4
ͷෆ๏ແ ઢہʹ͋ͨΓɼേͤΒΕ·͢ ͜͜Ͱ͍͏ແઢہͱϒϩʔυόϯυ์ૹͷϥδΦɼςϨϏͷૹ৴ࢪઃͩ ͚Ͱͳ͘ɼి๏ୈ 2 ୈ 5 ߸Ͱఆٛ͞ΕΔʮແઢઃඋٴͼແઢઃඋͷ ૢ࡞Λߦ͏ऀͷ૯ମʯΛࢦ͠·͢ 2 / 18
ϥδΦͷΈ ߭ੴϥδΦ ৼ෯มௐͷ߹ 同調回路 検波器 ローパス イヤホン アンテナ 3 /
18
ৼ෯มௐͷݕ 4 / 18
ಉௐճ࿏ ω0 = 1 √ LC , f0 = 1
2π √ LC ΠϯμΫλిྲྀͷมԽʹΑͬͯىిྗ͕ൃੜ ίϯσϯαిѹͷมԽʹΑͬͯిՙ͕มԽ VL(t) = L diL dt , iC(t) = C dVC dt ฒྻճ࿏Ͱɼ֤ૉࢠʹ͔͔Δిѹ͍͠ VL = VC ిؾճ࿏ͰɼશͯͷૉࢠʹྲྀΕΔిྲྀͷ͕ྵʹͳ Δ iC + iL = 0 d2i(t) dt2 + 1 LC i(t) = 0 同調回路 5 / 18
ݕճ࿏ ৴߸͔ΒแབྷઢΛͱΓͩ͢ ߭ੴμΠΦʔυ͕ϑΟϧλͱͳͬ ͍ͯΔ ࣮ḊͼͨΧϛιϦͷਕͱΤϯϐπ ͷਊͰΠέΔ ͍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
ΞφϩάϥδΦͷมભ ߭ੴϥδΦ ਅۭϥδΦʢฒࡾɼฒ࢛ɼߴҰͳͲʣ ࠷ॳग़ྗΛೖྗʹ͢ਖ਼ؼؐʹΑΔ૿෯͚ͩ εʔύʔϔςϩμΠϯ http://www.marutsu.co.jp/wp/datatech/4562/ 7 / 18
ϥδΦࠓੲ ͖͞΄Ͳ·Ͱɼੲͷ ΞφϩάϥδΦͩͱ৭ʑ໘ ૿෯ͱ͔νϡʔχϯάͱ͔ग़ྗஈͷՃͱ͔ ΈΜͳେ͖ DSP ͱμΠϨΫτίϯόʔδϣϯड৴ εʔύʔϔςϩμΠϯͷ IF Λ
0Hz ʹͨ͠ߏ 8 / 18
DSP ϥδΦ TV ͰϥδΦͰಉ͡ɽ࣮ܞଳిͰಉ͡ ৴߸Λ A/D ม͠ɼίϯϐϡʔλʹऔΓࠐΉ͚ͩ ͜ͷਤνϡʔφʔνοϓͷ R820T ͷσʔλγʔτΑΓ
9 / 18
I/Q ৴߸ ೖྗͷ RF ʹɼہ෦ൃৼث͔Β 90 ͦΕͧΕҐ૬͕ҟͳΔͷΛՃ͑Δ In-phase ৴߸ Quadrature-phase
৴߸ νϡʔφʔνοϓ I/Q ৴߸ʢϕʔεόϯυ৴߸ʣΛಘΔ 10 / 18
RTL2832U ΈΜͳେ͖ֈνοϓʂ Ҭଳͷड৴͕Մೳʂ Ξοϓίϯόʔτճ࿏ΛՃͨ͠Β GPS ৴߸ड৴Մೳ ͍͍ͩͨ 1 GHz ͙Β͍·Ͱड৴Մೳ
11 / 18
RTL2832U 12 / 18
RTL2832U 13 / 18
ͱ͜Ζ͜ͷ USB υϯάϧͬͯ ͦ͏Ͱ͢ɼϫϯηά TV ड৴༻ ͳΜͱळ༿ݪͰ 500 ԁͰߪೖ ΞϯςφΞϚνϡΞແઢͷ
144/430 MHz ༻Ͱɼ3000 ԁ͙Β͍ SDRʢSoftware-difined Radioʣ 14 / 18
͔͍͔ͭͨʂ RTL-SDR υϥΠόΛಋೖ ͋ͱ৭ʑௌ͚ͩ͘ʂ 15 / 18
ADS-B 16 / 18
GqrxʢGNU Radioʣ 17 / 18
·ͱΊ ੲϥδΦ࡞͕ిࢠ࡞ͷೖʹΑ͘ΘΕ͍ͯͨ ϥδΦ͔ΒΈΜͳ͕Ε͍ͯͬͯٱ͍͠ SDR ͰϥδΦΛௌ͘ͷྑ͍ͷͰͳ͍͔ Raspberry Pi ʹ͠ͱ͍ͯϑϥΠτϨʔμʔ࡞Δͱ͔؆୯ radiko ϞυΩΛՈʹ࡞ΔͷՄೳ
͍Ζ͍Ζ༡ΜͰΈΑ͏ʂ 18 / 18