Introduction to Digital Voice and DMR Reilly Grant K6YAP
Introduction to
Digital Voice and DMRReilly Grant
K6YAP
Digital Voice
timevoltage
Input signal
vo
lta
ge
time
Carrier
Amplitude Modulation Frequency Modulation
time voltage
0 0
1 1
2 2
3 3
4 4
5 3
6 2
7 1
8 0
⁞ ⁞
time
vo
lta
ge
value binary
0 000
1 001
2 010
3 011
4 100
3 011
2 010
1 001
0 000
⁞ ⁞
000001010011100011010001000
010110110101
0101110011001010
Original bit stream:
Compressed bit stream:
Error correction added:
Digital Modulation
time
vo
lta
ge
Bit stream: 1101101
tim
e
frequency
time
vo
lta
ge
Bit stream: 1101101
tim
e
frequency
Bit stream: 101100101001111000
tim
e
frequency
symbol frequency
00 +648 kHz
01 +1,944 kHz
10 -648 kHz
11 -1,944 kHz
DMR
Repeater station
TX: 444.35 MHzRX: 449.35 MHz
TX: 449.35 MHz
RX: 444.35 MHz
Handheld station
CC1
CC2
CC2
CC1
CC2
Same frequency
Different color code
TG31075
TG31075
TG31064
TG31064
TG31064
Source: ETSI TS 102 361-1 V2.5.1 (2017-10)
Source: ETSI TS 102 361-1 V2.5.1 (2017-10)
Source: ETSI TS 102 361-1 V2.5.1 (2017-10)
TG31075
TS2
TG31075
TS2
TG31064
TS1
TG31064
TS1
TG31064
TS1
Linked Repeaters
Internet
Site A
Site B
Site C
Site A Site B
network linkTG93
TS1
TG2
TS2
TG2
TS2
TG93
TS2
WW6BAY WA6YCZ
N6AMGKK6USZ
TG1: 91064
TG2: 91075
TG1: 93, 3106, 31064, 31065,
31075, 31096, 310604
TG2: 97150
TG1: 93, 3106, 31065,
31075, 31096, 310604
TG2: 97150
TG1: 3131, 31679
TG2: 31064, 31068, 31075,
110670
Programming
Questions?