Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
ソフトウェアラジオとC++ そしてFMエアチェックのための信号解析と数値計算にまつわるよもやま話 / Software radio and C++
Search
Kenji Rikitake
November 22, 2019
Technology
0
860
ソフトウェアラジオとC++ そしてFMエアチェックのための信号解析と数値計算にまつわるよもやま話 / Software radio and C++
A presentation for Kichijoji.pm 20, Freakout Holdings, Inc., Minato-ku, Tokyo, Japan, 22-NOV-2019
Kenji Rikitake
November 22, 2019
Tweet
Share
More Decks by Kenji Rikitake
See All by Kenji Rikitake
SDR Implementation of Analog FM Broadcast Multipath Filter
jj1bdx
0
660
インターネットとオープンな無線技術の今後 / Future of Internet and Open Radio Engineering
jj1bdx
0
1.1k
FM放送とマルチパスを適応フィルタで極めてみた / Solving multipath distortion of FM broadcast by adaptive filters
jj1bdx
1
3.3k
SDR時代のFM受信 マルチパスモニタとマルチパスフィルタ / FM broadcast reception with SDR - multipath monitor and multipath filter
jj1bdx
0
480
How I discover a working implementation of clock_nanosleep() for macOS in CPAN Time::Hires
jj1bdx
1
1k
Sleeping pays / 1000eng-74th-jj1bdx
jj1bdx
1
35
The BEAM Programming Paradigm
jj1bdx
1
810
Safe randomness: theory and practice
jj1bdx
1
1.2k
ただの失業したインターネット屋は果たして独立開業できたのか? / Did the fired internet engineer finally start up his business successfully as an independent consultant?
jj1bdx
1
440
Other Decks in Technology
See All in Technology
サーバーレスAPI(API Gateway+Lambda)とNext.jsで 個人ブログを作ろう!
shuntaka
PRO
0
560
スタートアップにおける組織設計とスクラムの長期戦略 / Scrum Fest Kanazawa 2024
yoshikiiida
13
3.6k
地理情報とAPIのトレンド
nagix
0
160
[NIKKEI Tech Talk]Bias for Action!! 実践から学ぶための仕組とコミュニティ / Community for Practice and Learning
kanamasa
0
270
Datadog Cloud SIEMを使ってAWS環境の脅威を可視化した話/lifeistech-datadog-cloud-siem
gidajun
0
480
[I/O Extended Android 2024] What`s new in Android 2024
kyeongwan
0
220
ゆめみのアクセシビリティの現在地と今後
ryokatsuse
3
290
データ分析基盤を作ってみよう~設計編~
nrinetcom
PRO
1
110
Flutter研修【MIXI 24新卒技術研修】
mixi_engineers
PRO
0
160
ギークの理想が7つ集まるエムスリーで夢を叶えよう - エムスリー株式会社
m3_engineering
1
260
可視化プラットフォームGrafanaの基本と活用方法の全て
hamadakoji
0
230
CTOから見た事業開発とプロダクト開発 / My Perspective on Business and Product Development as CTO
keisuke69
4
960
Featured
See All Featured
The Power of CSS Pseudo Elements
geoffreycrofte
64
5.2k
Reflections from 52 weeks, 52 projects
jeffersonlam
346
19k
Designing for Performance
lara
604
67k
Code Reviewing Like a Champion
maltzj
517
39k
Fight the Zombie Pattern Library - RWD Summit 2016
marcelosomers
228
16k
Optimizing for Happiness
mojombo
373
69k
Art, The Web, and Tiny UX
lynnandtonic
291
20k
It's Worth the Effort
3n
181
27k
The Cult of Friendly URLs
andyhume
75
5.9k
A designer walks into a library…
pauljervisheath
201
24k
Designing on Purpose - Digital PM Summit 2013
jponch
113
6.6k
Imperfection Machines: The Place of Print at Facebook
scottboms
262
13k
Transcript
ιϑτΣΞϥδΦͱC++ 1 ͦͯ͠FMΤΞνΣοΫͷͨΊͷ৴߸ղੳͱܭࢉʹ·ͭΘΔΑ· 1 ͜ͷൃදͰͷC++C++11Ҏ߱ͷ༷Λલఏͱ͍ͯ͠·͢ɻ Kenji Rikitake / Kichijoji.pm 20
1
Kenji Rikitake Γ͖͚ͨ ͚Μ͡ ྗ ݈࣍ 22-NOV-2019 kichijoji.pm 20 Freakout
Holdings, Inc. Minato-ku, Tokyo, Japan @jj1bdx Kenji Rikitake / Kichijoji.pm 20 2
ٕज़࢜ʢใֶ෦ʣ ྗ݈ٕ࣍ज़࢜ࣄॴ ॴ ใॲཧ҆શ֬อࢧԉ࢜ ϖύϘݚڀॴ ٬һݚڀһ ୈҰڃ্ແઢٕज़࢜ ୈҰڃΞϚνϡΞແઢٕ࢜ ΞϚνϡΞແઢྺ 438ϲ݄
Cྺ 33ɺC++11ྺ ͨͬͨͷ3 ຊݚڀͷϖύϘݚڀॴͷ͝ࢧԉʹਂ͘ײँ͠·͢ Kenji Rikitake / Kichijoji.pm 20 3
Kenji Rikitake / Kichijoji.pm 20 4
1970ྲྀߦͬͨFMΤΞνΣοΫ FM์ૹԻָͷࢁͩͬͨ ࢲ͍ͬͺ͍ϥδΧη2ͰԻͯ͠·ͨ͠ ʢ2019ͷࠓͰԻ͍ͯ͠Δਓୡ͍ͬͺ͍͍·͢ʣ 2 Puding Jahodový, Public domain, h4ps:/
/commons.wikimedia.org/wiki/File:Sharp_5P-37G_wiki.jpg, via Wikimedia Commons Kenji Rikitake / Kichijoji.pm 20 5
Kenji Rikitake / Kichijoji.pm 20 6
21ੈلͷϥδΦιϑτΣΞ USBσόΠε3ͰपมͱଳҬ੍ݶ มͨ͠৴߸ ιϑτΣΞ Ͱॲཧ ίʔυ͕ॻ͚Ε͋ͳͨϥδΦ͕࡞ΕΔ! ΤΞνΣοΫͨ͠MP3ϑΝΠϧεϚϗͰฉ͖์! 3 Photo of
Airspy HF+ Dual Port by Kenji Rikitake Kenji Rikitake / Kichijoji.pm 20 7
पมͱଳҬ੍ݶͷྫ 82.5MHzΛத৺ͱ͢ΔFM์ૹͷ߹ 82.308MHz - 82.692MHz ↓ -0.192MHz - 0.192MHz ±192kHzͷ384kHz෯ͷ৴߸ʹม
Kenji Rikitake / Kichijoji.pm 20 8
ෛͷप ࣮ͷ৴߸: ࣮ࡍͷՄೳੑ(1): ࣮ࡍͷՄೳੑ(2): ཧ༝: …ͳͷͰ࣮ͷ৴߸͚ͩͰ৴߸ͷҐ૬ΛಛఆͰ͖·ͤΜ ෛͷपΛߟ͑ͯΔඞཁ͕͋Γ·͢ Kenji Rikitake /
Kichijoji.pm 20 9
IQ৴߸: ࣮৴߸Λෳૉʹม ࣮ͷ৴߸: ͔ΒҎԼͷ৴߸Λੜ͠·͢ ରԠ͢ΔIQ৴߸: ͨͩ͠ ʢͳͥ͜Ε͕ Ͱͳ͍͔ͱ͍͏ͱిؾͰ ిྲྀͷҙຯͳͷͰ͢ʣ ͜ΕΛॻ͖͢ͱ
ʢۃ࠲ඪʣ I৴߸ʢ࣮෦ʣ: Q৴߸ʢڏ෦ʣ: Kenji Rikitake / Kichijoji.pm 20 10
IQ৴߸ͩͱԿ͕͏Ε͍͔͠ IQ৴߸: std::complex<float> IQsample ͱͯ͠ఆٛ ৴߸ͷৼ෯ std::abs(IQsample) ৴߸ͷҐ૬
std::arg(IQsample) std::arg(z) = std::atan2(z.imag(), z.real()) AM์ૹͳΒ ͦͷͷɺFM์ૹͳΒ Λඍ͢Ε෮ௐͰ͖Δ Kenji Rikitake / Kichijoji.pm 20 11
50લͷFM์ૹ։͔࢝࣌Βͷ·͍͠: FMͷ ࣭Լ͛Δ Ϛϧνύε Kenji Rikitake / Kichijoji.pm 20 12
Ϛϧνύε ෳܦ࿏Λ௨Δిͷׯব ৼ෯Ґ૬͕มԽͯ͠Ή Ґ૬͕ΉͱFM์ૹͩͱͱͯෆշͳԻ͕͢Δ ैདྷͷରԠ: ΞϯςφͷࢦੑͷมԽ͙Β͍͔͠Ͱ͖ͳ͔ͬͨ Kenji Rikitake / Kichijoji.pm
20 13
ϚϧνύεͰຊདྷͳ͍৴߸͕ݟ͑Δྫ4 4 Lithium57, English transla3on: MichaelBillington, h:ps:/ /commons.wikimedia.org/wiki/ File:Mul3path_propaga3on_diagram_en.svg from
Wikimedia Commons, public domain Kenji Rikitake / Kichijoji.pm 20 14
ϚϧνύεʹΑΔৼ෯ͷมԽ5 5 Audacity simula.on and graphics by Kenji Rikitake Kenji
Rikitake / Kichijoji.pm 20 15
ϚϧνύεԆͷΈࠐΈ6 6 I, Cantalamessa, h.ps:/ /commons.wikimedia.org/wiki/File:Mul>path_impulse_response.png from Wikimedia Commons, licensed
CC BY 2.5 Kenji Rikitake / Kichijoji.pm 20 16
ԆΛϞσϦϯάͯ͠ٯԋࢉ͢Δ FM৴߸: ৼ෯ҰఆɺҐ૬/पͷΈมԽ ৼ෯ͷมԽ→৴߸͕ΜͰ͍Δ มԽͨ͠ৼ෯Λ͢Α͏ͳΈࠐΈΛड৴ଆ Ͱͬͯ͠·͑Α͍ ʢLeast Mean Square /
Constant Modulus Algorithmʣ Kenji Rikitake / Kichijoji.pm 20 17
ٯԋࢉͷͨΊͷFIRϑΟϧλ (airspy-fmradion) using IQSample = std::complex<float>; using IQSampleVector = std::vector<IQSample>;
inline IQSample MultipathFilter::single_process(const IQSample filter_input) { m_state.emplace_back(filter_input); m_state.erase(m_state.begin()); IQSample output = IQSample(0, 0); // for (unsigned int i = 0; i < m_filter_order; i++) { // output += m_state[i] * m_coeff[i]; // } volk_32fc_x2_dot_prod_32fc(&output, m_state.data(), m_coeff.data(), m_filter_order); return output; } Kenji Rikitake / Kichijoji.pm 20 18
Vector Op*mized Library of Kernels (VOLK) x86/ARMͷ৴߸ॲཧͷͨΊͷϥΠϒϥϦ SIMD໋ྩͰΧϦΧϦͷϋϯυνϡʔχϯά h"p:/ /libvolk.org/
ʢFM෮ௐઐ༻ͷ͕ؔ͋ͬͨΓ͢Δ͘Β͍ΨνͰ͢ʣ Kenji Rikitake / Kichijoji.pm 20 19
ྗͷGPLv3࣮ = airspy-fmradion h"ps:/ /github.com/jj1bdx/airspy-fmradion ͱͱSo#FMͱ͍͏FMड৴ઐ༻ػ ࠓதAM/FM/SSB/CWͳΜͰ͟͝ΕʹਐԽ ͓ͦΒ͘ੈքॳͷOSSͰ࣮ͨ͠ϚϧνύεϑΟϧλ macOSͱLinuxͱRaspberry PiͰಈ͖·͢
ʢGUIෆಘҙͳͷͰʣίϚϯυϥΠϯπʔϧ Ͱ͢ Kenji Rikitake / Kichijoji.pm 20 20
࠷ޙʹҰ۟ ౙͷʹ ཕΛ͑Δ ి ʢౙͷʹ֤Ͱൃੜ͢Δཕ͕ిΛհͯ͠த์ૹ3.9MHzʢ75mόϯυʣͷ์ૹͰຊதʹ͘·ͳ͘ΘΔ༷Λࣔͨ͠Ұ۟ɻͳ͓ɺཕʢΒ͍ʣຊདྷՆͷقޠɻʣ Kenji Rikitake / Kichijoji.pm 20
21
ܾҙද໌ 2020ʹ౦ژʹͬͨΒ ؤுͬͯͬͱՔ͍Ͱ ΑΓΑ͍ݚڀͱٕज़Ͱ ࣾձʹߩݙ͠·͢ Kenji Rikitake / Kichijoji.pm 20
22
Thank you Ques%ons? Kenji Rikitake / Kichijoji.pm 20 23