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CC112X/CC1175
SWRU295C
Page 25 of 108
The symbol encoding can be configured through the
SOFT_TX_DATA_CFG.SYMBOL_MAP_CFG
register field as shown in Table 12
SYMBOL_MAP_CFG = 00b
by default).
Format
Symbol
Coding
SYMBOL_MAP_CFG
= 00b
SYMBOL_MAP_CFG
= 01b
SYMBOL_MAP_CFG
= 10b
SYMBOL_MAP_CFG =
11b
2-(G)FSK
OOK/ASK
„0‟
−Deviation [A
Min
]
+Deviation [A
Max
]
+Deviation[A
Max
]
+Deviation [A
Max
]
„1‟
+Deviation [A
Max
]
−Deviation [A
Min
]
−Deviation [A
Min
]
−Deviation [A
Min
]
4-(G)FSK
„00‟
−Deviation /3
−Deviation
+Deviation /3
+Deviation
„01‟
−Deviation
−Deviation /3
+Deviation
+Deviation /3
„10‟
+Deviation /3
+Deviation
−Deviation /3
−Deviation
„11‟
+Deviation
+Deviation /3
−Deviation
−Deviation /3
Table 12: Symbol Encoding for 2-(G)FSK and 4-(G)FSK Modulation
4.1.2
Amplitude Modulation (ASK) and on-off keying (OOK)
CC112X
supports two different forms of amplitude modulation: On-Off Keying (OOK) and Amplitude
Shift Keying (ASK).
OOK modulation simply turns the PA on or off to modulate ones and zeros respectively.
OOK/ASK in
CC112X
allows programming of the modulation depth (the difference between 1 and 0),
and shaping of the pulse amplitude. Pulse shaping produces a more bandwidth constrained output
spectrum (see Figure 10 for shaped/unshaped spectrum).
Figure 10: OOK with and without shaping
3
A
Min
= Minimum Amplitude and A
Max
= Maximum Amplitude when OOK/ASK is used