What is the data speed in QPSK?

In Quadrature Phase Shift Keying (QPSK), data speed is determined by the symbol rate and the number of bits encoded per symbol. QPSK transmits two bits of data per symbol by utilizing four distinct phase shifts (0°, 90°, 180°, and 270°). Therefore, if the symbol rate is R symbols per second, the data speed can be calculated as 2R bits per second. This allows QPSK to achieve a higher data rate compared to simpler modulation schemes like BPSK, which only transmits one bit per symbol.