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M-DPSK Modulator Baseband

Modulate using M-ary differential phase shift keying method

Library

PM, in Digital Baseband sublibrary of Modulation

  • M-DPSK Modulator Baseband block

Description

The M-DPSK Modulator Baseband block modulates using the M-ary differential phase shift keying method. The output is a baseband representation of the modulated signal. TheM-ary numberparameter, M, is the number of possible output symbols that can immediately follow a given output symbol.

The input must be a discrete-time signal. For integer inputs, the block can accept the data typesint8,uint8,int16,uint16,int32,uint32,single, anddouble. For bit inputs, the block can acceptint8,uint8,int16,uint16,int32,uint32,boolean,single, anddouble.

The input can be either bits or integers, which are binary-mapped or Gray-mapped into symbols.

This block accepts column vector input signals. For a bit input, the input width must be an integer multiple of the number of bits per symbol.

Integer-Valued Signals and Binary-Valued Signals

If you set theInput typeparameter toInteger, then valid input values are integers between 0 and M-1. In this case, the input can be either a scalar or a frame-based column vector. If the first input is k1, then the modulated symbol is

exp ( j θ + j 2 π k 1 m )

where θ represents thePhase rotationparameter. If a successive input isk, then the modulated symbol is

exp ( j θ + j 2 π k m ) ⋅ ( previous modulated symbol )

When you set theInput typeparameter toBit,阻止接受binary-valued repr输入esent integers. The block collects binary-valued signals into groups ofK= log2(M) bits

where

Krepresents the number of bits per symbol.

The input vector length must be an integer multiple ofK. In this configuration, the block accepts a group ofKbits and maps that group onto a symbol at the block output. The block outputs one modulated symbol for each group ofKbits.

The input can be a column vector with a length that is an integer multiple ofK.

In binary input mode, theConstellation orderingparameter indicates how the block maps a group ofKinput bits to a corresponding phase difference. TheBinaryoption uses a natural binary-to-integer mapping, while theGrayoption uses a Gray-coded assignment of phase differences. For example, the following table indicates the assignment of phase difference to three-bit inputs, for both theBinaryandGrayoptions. θ is thePhase rotationparameter. The phase difference is between the previous symbol and the current symbol.

Current Input Binary-Coded Phase Difference Gray-Coded Phase Difference
[0 0 0] jθ jθ
[0 0 1] jθ + jπ/4 jθ + jπ/4
[0 1 0] jθ + jπ2/4 jθ + jπ3/4
[0 1 1] jθ + jπ3/4 jθ + jπ2/4
[1 0 0] jθ + jπ4/4 jθ + jπ7/4
[1 0 1] jθ + jπ5/4 jθ + jπ6/4
[1 1 0] jθ + jπ6/4 jθ + jπ4/4
(1 1 1) jθ + jπ7/4 jθ + jπ5/4

For more details about theBinaryandGrayoptions, see the reference page for theM-PSK Modulator Basebandblock. The signal constellation for that block corresponds to the arrangement of phase differences for this block.

Dialog Box

M-ary number

The number of possible output symbols that can immediately follow a given output symbol.

Input type

Indicates whether the input consists of integers or groups of bits. If this parameter is set toBit, then theM-ary numberparameter must be 2Kfor some positive integer K.

Constellation ordering

Determines how the block maps each group of input bits to a corresponding integer.

Phase rotation (rad)

The phase difference between the previous and current modulated symbols when the input is zero.

Output data type

The output data type can be eithersingleordouble. By default, the block sets this todouble.

Supported Data Types

Port Supported Data Types

Input

  • Double-precision floating point

  • Single-precision floating point

  • Boolean (binary input mode only)

  • 8-, 16-, and 32-bit signed integers

  • 8-, 16-, and 32-bit unsigned integers

Output

  • Double-precision floating point

  • Single-precision floating point

References

[1] Pawula, R. F., "On M-ary DPSK Transmission Over Terrestrial and Satellite Channels,"IEEE Transactions on Communications, Vol. COM-32, July 1984, 752-761.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

See Also

Blocks

Introduced before R2006a

Communications Toolbox Documentation

万博1manbetx

Bridging Wireless Communications Design and Testing with MATLAB

Bridging Wireless Communications Design and Testing with MATLAB

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