Difference between bpsk and qpsk

As mentioned above in the table, BPSK represents binary input 1 and 0 w.r.t. change in carrier phase by 180 degree. While QPSK represents two bits using complex carrier symbol each having 90 degree shift with one another.

1. Why the QPSK is better than BPSK?
2. What is the difference between BPSK and DPSK?
3. Why is QPSK and BPSK the same?
4. What is the difference between PSK and QPSK?

Why the QPSK is better than BPSK?

Quadrature phase-shift keying (QPSK).

In comparison to OOK and BPSK, QPSK enables the data rate to be doubled while keeping the same bandwidth, meaning it's also possible to stay at the same data rate at half the bandwidth, with the same bit error ratio (BER). So QPSK is suitable for data rates of 100 Gbps as well.

What is the difference between BPSK and DPSK?

DPSK is a technique of BPSK, in which there is no reference phase signal. Here, the transmitted signal itself can be used as a reference signal. Following is the diagram of DPSK Modulator. DPSK encodes two distinct signals, i.e., the carrier and the modulating signal with 180° phase shift each.

Why is QPSK and BPSK the same?

The probability of error is identical for BPSK and QPSK because the BER has been measured in terms of signal to noise ratio per bit.

What is the difference between PSK and QPSK?

QPSK allows the signal to carry twice as much information as ordinary PSK using the same bandwidth. QPSK is used for satellite transmission of MPEG2 video, cable modems, videoconferencing, cellular phone systems, and other forms of digital communication over an RF carrier.