Scicos Block
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I/Q demodulator block

Contents

• I/Q demodulator block
  • Palette
  • Description
  • Basic blocks equivalent model
  • Dialog box
  • Default properties
  • Interfacing function
  • Computational function
  • See also
  • Authors

Palette

• Communication - Communication palette

Description

This block realizes a complex demodulation in time domain and computes :

$$\begin{eqnarray} y_{1}(t) = u_{1}\cos\left(\omega_{o}t\right)+u_{2}\sin\left(\omega_{o}t\right) \end{eqnarray}$$

$$\begin{eqnarray} y_{2}(t) = u_{2}\cos\left(\omega_{o}t\right)-u_{1}\sin\left(\omega_{o}t\right) \end{eqnarray}$$

with u1, u2 are the regular inputs and y1,y2 the outputs. wo is the dialogue parameter "vector of frequencies". This is the pair block of the MODIQ_f block.

Basic blocks equivalent model

Dialog box

• Vector of carrier frequency
  The vector of the free-running frequencies of local oscillators.
  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
  - port 2 : 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: 1
• number/sizes of activation outputs: 0
• continuous-time state: no
• discrete-time state: no
• object discrete-time state: no
• name of computational function: demodiq

Interfacing function

• MODNUMCOS/macros/scicos_blocks/Communication/DEMODIQ_f.sci [view code]

Computational function

• MODNUMCOS/routines/communication/demodiq.c (Type 2) [view code]

See also

• MODIQ_f - I/Q modulator block (Scicos Block)

Authors

IRCOM Group Alan Layec