Question

Is QPSK is not secured network?

Is QPSK shared?

Answer 1

For standard constellation patterns which are centrally symmetric are not recognized are said to be unsecure as the information can be detected easily, but by setting the constellation points modulated for QPSK for 45 degrees can be properly detected understood at receivers end. So by selecting the contellation point locations to some degrees it is possible to detect the trasmitted signal only in one direction. So we can say that by setting the appropriate constellation points is very useful for incorporating security in data transmission can be achieved.. We can make QPSK systems more secure by limiting the transmitted signal constellation IQ pattern only for predefined communictaion direction and complete distruction of constellation patterns along all other unknown communication directions. And thus we can say that it is posible to have secured data transmission with QPSK.

Hence QPSK can be useful for secured data transmission.

For the equal data rates of the in-phase (I) and quadrature phase (Q) signal components QPSK modulation provides best power and spectral contents. In general the total power is shared between the in-phase (I) and quadrature phase (Q) signal components and that power is proportional to the magnitudes of the in-phase (I) and quadrature phase (Q) signal components of the modulated carrier.

So as the power is shared between I & Q components we can say that QPSK is shared