Integer-Valued Signals and Binary-Valued Signals

When you set theInput typeparameter toInteger, the valid input values are 0, 1, 2, and 3. In this case, the block accepts a scalar or column vector input signal. If the first input ism, then the modulated symbol is

where θ represents thePhase rotationparameter. If a successive input ism, then the modulated symbol is the previous modulated symbol multiplied by exp(jθ + jπm/2).

When you set theInput typeparameter toBit, the input contains pairs of binary values. In this case, the block accepts a column vector whose length is an even integer. The following figure shows the complex numbers by which the block multiples the previous symbol to compute the current symbol, depending on whether you set theConstellation orderingparameter toBinaryorGray。The following figure assumes that you set thePhase rotationparameter to $$\frac{\Pi }{4}$$; in other cases, the two schematics would be rotated accordingly.

The following figure shows the signal constellation for the DQPSK modulation method when you set thePhase rotationparameter to $$\frac{\Pi }{4}$$。The arrows indicate the four possible transitions from each symbol to the next symbol. TheBinaryandGrayoptions determine which transition is associated with each pair of input values.

More generally, if thePhase rotationparameter has the form $$\frac{\Pi }{k}$$for some integerk, then the signal constellation has 2kpoints.