JS Kongress 2017: Building a radio data network with Node.js

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@wa7son

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Who am I? • Thomas Watson • Open Source developer at github.com/watson • Node.js Engineer at Elastic • Member of the Diagnostics Working Group under the Node.js Foundation • Tweets as @wa7son @wa7son

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Radio Data Network Building a @wa7son With Node.js

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In Software Reimplementing WiFi @wa7son

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Software Deﬁned Radio @wa7son

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@wa7son Expensive: $5,000+

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@wa7son • DVB-T • DAB • FM Marketed as TV / radio tuner for: Contains a Realtek RTL2832U chip Supports approx. 24 MHz – 1766 MHz Hackable! Cheap: $10 - $20

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@wa7son Funded by: Affordable: $299

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Radio 101 @wa7son

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@wa7son

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@wa7son

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@wa7son

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@wa7son

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Demo Time Modulation @wa7son

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“In electronics and telecommunications, modulation is the process of varying one or more properties of a periodic waveform, called the carrier signal, with a modulating signal that typically contains information to be transmitted.” @wa7son - Wikipedia

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@wa7son

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@wa7son

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@wa7son Girls

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@wa7son

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@wa7son

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Digital Modulation @wa7son

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@wa7son 0110101110…

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@wa7son On/Off Keying (OOK)

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@wa7son Symbols 0: No voltage 1: High voltage Symbol rate = Bit rate 1 bit = 1 symbol

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The Three Basic Modulation Types @wa7son

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@wa7son 56K = 56,000 bits/sec 8000 baud = 8,000 symbols/sec 56,000/8,000 = 7 bits/symbol

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QAM Quadrature Amplitude Modulation One Modulation To Rule Them All @wa7son

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Remember Trigonometry? @wa7son

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What is a sine wave? @wa7son

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What is a sine wave? @wa7son

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The Unit Circle @wa7son

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4 QAM Modulation @wa7son

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16 QAM Modulation @wa7son

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16 QAM Modulation @wa7son Practical Signal Processing, ISBN: 978-1-107-41182-1

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Error Correction @wa7son

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• 1949 - Golay Codes (Voyager 2: Jupiter and Saturn missions in ’79-’81) • 1950 - Hamming Codes (ECC memory) • 1954 - Reed-Muller Codes (Mariner spacecraft in ’69-’77) • 1960 - Reed-Solomon Codes (Voyager 2 in ’77 + CD, DVD, Blueray, Barcodes) • 1993 - Turbo Codes (3G/4G e.g. UMTS+LTE + deep space satellite communication) Error-Correction Codes @wa7son

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npm install @ronomon/reed-solomon @wa7son

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Demo @wa7son

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References github.com / watson / monster-drift github.com / mappum / node-hackrf greatscottgadgets.com / sdr @wa7son @wa7son

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@wa7son github.com/watson Danke