CC1110Fx / CC1111Fx
13.9.2
Minimum Shift Keying
13.9.3
Amplitude Modulation
When using MSK21, the complete transmission
(preamble, sync word, and payload) will be
MSK modulated.
CC1110Fx/CC1111Fx supports two different forms
of amplitude modulation: On-Off Keying (OOK)
and Amplitude Shift Keying (ASK).
Phase shifts are performed with a constant
transition time.
OOK modulation simply turns on or off the PA
to modulate 1 and 0 respectively.
The fraction of a symbol period used to change
the phase can be modified with the
DEVIATN.DEVIATION_M setting. This is
equivalent to changing the shaping of the
symbol.
The ASK variant supported by the
CC1110Fx/CC1111Fx allows programming of the
modulation depth (the difference between 1
and 0), and shaping of the pulse amplitude.
Pulse shaping will produce a more bandwidth
constrained output spectrum.
The MSK modulation format implemented in
CC1110Fx/CC1111Fx inverts the sync word and
data compared to e.g. signal generators.
Note: The DEVIATNregister setting has no
effect in either RX or TX when using
OOK/ASK.
Note: The DEVIATN register setting
has no effect in RX when using MSK. Also,
when
using
MSK
Manchester
encoding/decoding should be disabled
(MDMCFG2.MANCHESTER_EN=0)
21
Identical to offset QPSK with half-sine
shaping (data coding may differ)
13.10 Received Signal Qualifiers and Link Quality Information
CC1110Fx/CC1111Fx has several qualifiers that
MDMCFG2.
Sync Word Qualifier Mode
can be used to increase the likelihood that a
SYNC_MODE
valid sync word is detected.
000
No preamble/sync
001
15/16 sync word bits detected
16/16 sync word bits detected
30/32 sync word bits detected
13.10.1 Sync Word Qualifier
010
If sync word detection in RX is enabled in
register MDMCFG2 the CC1110Fx/CC1111Fx will not
011
100
No preamble/sync, carrier sense
above threshold
start writing received data to the RFD register
and perform the packet filtering described in
Section 13.8.3 before a valid sync word has
been detected. The sync word qualifier mode
is set by MDMCFG2.SYNC_MODE and is
summarized in Table 67. Carrier sense in
Table 67 is described in Section 13.10.4.
101
110
111
15/16 + carrier sense above threshold
16/16 + carrier sense above threshold
30/32 + carrier sense above threshold
Table 67: Sync Word Qualifier mode
13.10.2 Preamble Quality Threshold (PQT)
The Preamble Quality Threshold (PQT) sync-
word qualifier adds the requirement that the
received sync word must be preceded with a
preamble with a quality above a programmed
threshold.
Another use of the preamble quality threshold
is as a qualifier for the optional RX termination
SWRS033H
Page 197 of 246
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