4.4 Modulator-Demodulator

For Bluetooth 1.2 specification and below, 1 Mbps is the standard data rate based on the Gaussian Frequency Shift Keying (GFSK) modulation scheme. This basic rate modulator-demodulator (Modem) meets Basic Data Rate (BDR) requirements of Bluetooth 2.0 with Enhanced Data Rate (EDR) specifications.

For Bluetooth 2.0 and above specifications, EDR is introduced to provide the data rates of 1/2/3 Mbps. For baseband, both BDR and EDR utilize the same 1 MHz symbol rate and 1.6 kHz slot rate. For BDR, symbol 1 represents 1-bit. However, each symbol in the payload part of the EDR packet represents 2 or 3 bits. This is achieved by using two different modulations, π/4 DQPSK and 8 DPSK.