Demodulate DPSKmodulated data
PM, in Digital Baseband sublibrary of Modulation
The MDPSK Demodulator Baseband block demodulates a signal that was modulated using the Mary differential phase shift keying method. The input is a baseband representation of the modulated signal. The input and output for this block are discretetime signals. This block accepts a scalarvalued or column vector input signal. For information about the data types each block port supports, see the Supported Data Types table on this page.
The Mary number parameter, M, is the number
of possible output symbols that can immediately follow a given output
symbol. The block compares the current symbol to the previous symbol.
The block's first output is the initial condition of zero (or a group
of zeros, if the Output type parameter is set
to Bit
) because there is no previous symbol.
If you set the Output type parameter to Integer
,
then the block demodulates a phase difference of
θ + 2πk/M
to k, where θ represents the Phase
rotation parameter and k represents
an integer between 0
and M1.
When you set the Output type parameter
to Bit
, the block outputs binaryvalued
signals that represent integers. The block represents each integer
using a group of K = log_{2}(M)
bits, where K represents the number of bits per
symbol. The output vector length must be an integer multiple of K.
In binary output mode, the symbols can be either binarydemapped or Graydemapped. The Constellation ordering parameter indicates how the block maps an integer to a corresponding group of K output bits. See the reference pages for the MDPSK Modulator Baseband and MPSK Modulator Baseband blocks for details.
The number of possible modulated symbols that can immediately follow a given symbol.
Determines whether the output consists of integers or groups of bits.
Determines how the block maps each integer to a group of output bits.
This phase difference between the current and previous modulated symbols that results in an output of zero.
When the parameter is set to 'Inherit via internal
rule'
(default setting), the block will inherit the output
data type from the input port. The output data type will be the same
as the input data type if the input is of type single
or double
.
For integer outputs, this block can output the data types int8
, uint8
, int16
, uint16
, int32
, uint32
, single
,
and double
. For bit outputs, output can be int8
, uint8
, int16
, uint16
, int32
, uint32
, boolean
, single
,
or double
.
Port  Supported Data Types 

Input 

Output 

[1] Pawula, R. F., "On Mary DPSK Transmission Over Terrestrial and Satellite Channels," IEEE Transactions on Communications, Vol. COM32, July 1984, 752761.