D-STAR System - American Radio Relay League（D-STAR系统美国无线电中继联赛）.pdf

D-STAR System Technical Requirements for the Wireless System 1.1 Voice Communication 1.1.1 General Terms (1) Communication Method Half-duplex, digitized voice transmissions. (2) Communication Contents Digitized voice/audio signals and short data messages are supported. Voice and audio streams are transmitted synchronously to support communications quality reproduction. Data and voice/audio transmissions are interleaved. 1.1.2 Transmitting Equipment (1) Modulation methods GMSK QPSK 4FSK (2) Data rate Maximum of 4.8 Kbps (3) Voice encoding method AMBE (2020) converting at 2.4 Kbps FEC at 3.6 Kbps (4) Occupied bandwidth Maximum of 6 KHz 1.1.3 Tx / Rx Switching time Less than 100ms. 1.2 Data Communication 1.2.1 General Terms (1) Communication Method Simplex (2) Communication Contents Digital data stream is supported. 1 1.2.2 Transmitting Equipment (1) Modulation method GMSK QPSK 4FSK (2) Data rate Maximum of 128 Kbps (3) Occupied bandwidth Maximum of 150 KHz 1.1.3 Switching time (Tx-Rx) Less than 50ms. 1.3 Backbone communication 1.3.1 General Terms (1) Transmission Method Full duplex. (2) Transmission Contents Backbone communication between repeaters containing multiplexed digitized voice/audio, user data, and link control data signals. 1.3.2 Transmitting Setup (1) Output power Complies with FCC regulations. (2) Modulation method GMSK