User's Manual

Bluegiga Technologies Oy
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10 Enhanced Data Rate
EDR has been introduced to provide 2x and optionally 3x data rates with minimal disruption to higher layers of
the Bluetooth stack. CSR supports both of the new data rates, with WT32. WT32 is compliant with revision
v2.0.E.2 of the specification.
10.1 Enhanced Data Rate Baseband
At the baseband level, EDR uses the same 1.6kHz slot rate as basic data rate and therefore the packets can
be 1, 3, or 5 slots long as per the basic data rate. Where EDR differs from the basic data rate is that in the
same 1MHz symbol rate, 2 or 3 bits are used per symbol, compared to 1bit per symbol used by the basic data
rate. To achieve the increase in number of bits symbol, two new modulation schemes have been introduced
as summarized in Table 24 presented below and the modulation schemes are explained in the further
sections.
Scheme Bits per symbol Modulation
Basic data rate 1 GFSK
Enhanced data rate 2 P/4 DQPSK
Enhanced data rate 3 8DPSK (optional)
Table 24: Data rate schemes
Although the EDR uses new packets, link establishment and management are unchanged and still use Basic
Rate packets.
10.2 Enhanced Data Rate ∏/4 DQPSK
4-state Differential Phase Shift Keying
2 bits determine phase shift between consecutive symbols
2 bits determine phase shift between consecutive symbols
∏ /4 rotation avoids phase shift of ∏ , which would cause large amplitude variation
Raised Cosine pulse shaping filter to further reduce side band emissions
Bit pattern Phase shift
00

01

10

11 
Table 25: 2 bits determine phase shift between consecutive symbols