BC41B143A-DS-001PE Datasheet, PDF (49/102 Pages) List of Unclassifed Manufacturers – BlueCpre 4-ROM Single Chip Bluetooth v2.0 System with EDR

Enhanced Data Rate
01
00
11
10
Figure 9.2: π/4 DQPSK Constellation Pattern
Bit Pattern
Phase Shift
00
π/4
01
3π/4
11
-3π/4
10
-π/4
Table 9.2: 2-Bits Determine Phase Shift Between Consecutive Symbols
9.3 Enhanced Data Rate 8DPSK
The 3x data rate modulation uses eight phase differential phase shift keying (8DPSK). Each symbol in the
payload portion of the packet represents three baseband bits. Although 8DPSK appears to be similar to π/4
DQPSK, the differential phase shifts between symbols are now permissible between any of the eight possible
phase states. This reduces the separation between adjacent symbols on the constellation to π/4 (45°C) and
thereby reduces the noise and interference immunity of the modulation scheme. Nevertheless, since each
symbol now represents 3 baseband bits, the actual throughput of the data is 3x when compared with the basic
data rate packet.
Figure 9.3 illustrates the 8DPSK constellation and Table 9.3 defines the phase encoding.
BC41B143A-ds-001Pe
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