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Subject: Re: Simulink: Modelling a DAC conversion and continuous time transfer function
Date: Sun, 28 Dec 2008 16:42:01 +0000 (UTC)
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hi all 
I need to convert a continuous sine signal to a 4 digit binary signal

thank u
npelly@gmail.com wrote in message <1103097289.775096.83700@c13g2000cwb.googlegroups.com>...
> Hi all,
> 
> I am in the process of learning simulink in order to model a signal
> processing system for wireless RF communications, however I have hit a
> bit of a dead-end on what must be a pretty simple problem.
> 
> To cut a long story short, I want to produce 4 level symbols, apply
> pulse shaping (in a DSP), then convert to a continuous signal and apply
> a filter that models an analog receiver circuit.
> 
> The 4 level symbols and pulse shaping are all done in the discrete time
> world, with a symbol rate of 9600 and 6 samples per symbol. This is
> working perfectly.
> 
> What I can't work out is how to:
> A) convert the discrete signal to a continuous signal. Is it just a
> ZOH+LPF? Or should I use some kind of generic DAC unit?
> 
> B) produce a continuous time filter to model the receiver circuit. I
> have its frequency response, and I am quite capable of producing a
> digital filter from this frequency response, but when it comes to the
> continuous time world I am a little clueless as to what block elements
> I should be using.
> 
> Any advice would be appreciated
> 
> regards,
> Nick
>