4.4 Modem

For Bluetooth 1.2 specifications and below, 1 Mbps is the standard data rate based on the Gaussian Frequency Shift Keying (GFSK) modulation scheme. This basic rate modem meets BDR requirements of Bluetooth 2.0 with EDR specifications.

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