MODPSK

Scicos Block
fr - eng

M-ary Phase Shift Keying Modulator block

$\epsfig{file=MODPSK_f.eps,height=117pt}$

M-ary Phase Shift Keying Modulator block

Palette

Communication - Communication palette

Description

This M-PSK modulator block computes the values of In phase/Quadrature (I/Q) components from integer values given in input. The phase is computed with the equation :

$\begin{eqnarray} \varphi&=&\pi\left(\frac{2u+1}{M}\right) \end{eqnarray}$

where u is the input integer value and M is the number of states defined with the dialogue parameter 'Number of states'. The values of outputs are given by :

$\begin{eqnarray} y_{1}&=&cos\left(\varphi\right) \\ y_{2}&=&-\sin\left(\varphi\right). \end{eqnarray}$

For example, for 4 and 8 PSK modulations, this bloc gives the following constellation diagrams :

$\begin{figure}\centering \scalebox{0.8}{% \input{constel_psk_ex.pstex_t}} \end{figure}$

Figure 1: 4 and 8 PSK constellation diagrams

Dialog box

$\begin{figure}\begin{center} \epsfig{file=MODPSK_f_gui.eps,width=270pt} \end{center}\end{figure}$

Number of states
The number of states of the modulation.
Type 'vec' de taille 1.
Inherit (no:0, yes:1)
Herits events by its regular input ports (disable the event input port).
Type 'vec' de taille 1.

Default properties

always active: no
direct-feedthrough: yes
zero-crossing: no
mode: no
regular inputs:
- port 1 : size [1,1] / type 1
regular outputs:
- port 1 : size [1,1] / type 1
- port 2 : size [1,1] / type 1
number/sizes of activation inputs: 0
number/sizes of activation outputs: 0
continuous-time state: no
discrete-time state: no
object discrete-time state: no
name of computational function: modpsk

Interfacing function

MODNUMCOS/macros/scicos_blocks/Communication/MODPSK_f.sci [view code]

Computational function

MODNUMCOS/routines/communication/modpsk.c (Type 4) [view code]

Authors

A. Layec