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Published bySabrina Cain Modified over 9 years ago
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D-STAR A New Way to Communicate
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Digital Radio System Open System Not Encrypted JARL
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・ The terminal is not heavily restricted by the system ・ Compatibility with the Internet ・ Necessity for user’s to be able to make by themselves ・ Operation as a single system with sequential expansion possible via infrastructure maintenance 。 ・ Necessity for communication with existing analog systems Requirements of an Amateur Radio Digital System
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Simplex Repeaters Backbone Digital Voice High Speed Data
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Digital data communication via local repeater.
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Digital voice communication via local repeater.
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Backbone communication between two repeater sites.
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Digital transceiver ID-1
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Block Diagram of ID-1
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Specification Operating Frequency: 1.2GHz Amateur Band Operating MODE: FM (analog voice) (FDMA) 0.5GMSK (Digital voice / DATA) Data Rate: 8kbps(voice) / 128kbps(data) CODEC: ITU G723.1 Data interface: IEEE802.3 (10Base-T ) RF Power: 10W / 1W Rx Sensitivity: FM -16dBu (typical) 8kbps GMSK voice -10dBu 128kbps GMSK Data +2dBu Switching Time: 10mS(Digital mode) GMSK Modulation: Quadrature Modulator / FPGA(Base Band)
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1.2GHz Data Repeater 1.2GHz Voice Repeater 1.2GHz Antenna Local repeaters and antenna
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10GHz 90cmφ parabola antenna10GHz backbone repeater Backbone repeater and antenna
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Composition of the repeater site
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Repeater site details
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Wire connection of the repeater site TX Antenna TX Antenna Conneter RX TX CNT b 13.8V Local Repeater b RX TX CNT c 13.8V Local Repeater c TX Antenna RX Antenna RX Antenna RX Antenna TX Antenna RX TX CNT d 13.8V Local Repeater d BRb R X BRb TX 13.8V Backbone Repeater b TX RX TX CNT b CNT c CNT d 13.8V BR a T X BR a R X BRb R X BRb TX Local Repeater a Tel.Line DC 13.8V Telephone Line BR a TX BR a R X 13.8V Backbone Repeater a TX RX
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D-STAR protocol Data communication protocol Voice communication protocol Backbone protocol USB of ID-1 control software Application software Software and protocol
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Composition of Data packet frame Data communication protocol
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Message transfer
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Voice communication protocol Composition of Voice packet frame
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ATM( Asynchronous Transfer Mode ) ATM Cell (53byte) → 48byte 5byte Header Payl oad Header Payl oad Backbone protocol
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Timing of the backbone signals
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Remote control by personal computer
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The Internet or server access Applications
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Small data communications to use data frames in the voice packet. Applications
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CODEC ・ ACELP (Algebraic Code Excited Linear Prediction) (ITU G723.1) ・ AMBE (Advanced Multi-Band Excitation) ・ VSELP (Vector Sum Exited Linear Prediction) ・ CELP (Code Exited Linear Prediction) ・ RELP (Residual Excited Linear Prediction) MIC A/D Convert Digital signal
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・ ACELP (Algebraic Code Excited Linear Prediction) ・ Low bit rate 5.3Kbps (include 6.3Kbps) ・ Frame size 30mS ・ Algorithm delay 37mS ITU G723.1 CODEC
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・ AMBE Coder divides each segment of speech into distinct frequency bands. ・ And makes a voiced/unvoiced decision for each frequency band. ・ This allows the excitation signal for a particular speech segment to be a mixture of periodic and noise-like energy. AMBE CODEC IC
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D-STAR System
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