Spread Spectrum Techniques found in LPRF & GNSS

Bluetooth – Dynamic Frequency Hopping – to avoid RF collisions

ZigBee – Transformation of bit patterns from 4 to 32 bits using Modulo-2 Spreading Code – to provide error detection and correction

GNSS – Use of modulo-2 Spreading Codes to achieve Code Division Multiple Access with a code correlator

Spread Spectrum Techniques found in LPRF & GNSS

Bluetooth – Dynamic Frequency Hopping – to avoid RF collisions

Direct Sequence Spread SpectrumZigBee – Transformation of bit patterns from 4 to 32 bits using Modulo-2 Spreading Code – to provide error detection and correction

CODE DIVISION MULTIPLE ACCESSGNSS – Use of modulo-2 Spreading Codes to achieve Code Division Multiple Access with a code correlator

BINARY GNSS CODE 0011101001010....BINARY GNSS CODE 0011101001010....

PSEUDO RANDOM NOISE (PRN) 1023 BITS

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Correlation

Infra Red Data Association IRDAUART like IR based protocol – typically 115200 BPS

Other speeds2400, 9600, 19200, 38400, 57600, 115200, 576000, 1152000, and

4000000 bits per secondSub Carrier x16 – min bit is 3 clocks wide

IR -Comm – simple serial commsOBEX – HTTP like Object Exchange Protocol

Infra Red Data Association IRDA

Image taken from texas Instruments TIR1000, TIR1000I

STANDALONE IrDAENCODER AND DECODER

Radio Frequency ID

Passive uses electo-magnetic couplingActive has internal power source

Range of frequencies125 - 134 kHz13.56 MHzUHF (400MHx and 860 to 960 MHz)2.45 GHz5.8 GHz