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Find delay, BPSK Simulink problem & QAM Simulink problem

Started by vcteo November 14, 2005
Q1:

I'm simulation BPSK with Convolutional Encoding in Simulink. I use
the Error Rate Calculation block to calculate the delay between Tx
and Rx.

The error rate block contains a recieve delay parameter which has to
be inserted with the value of the delay between its 2 inputs. I used
the Find delay block to find the delay between Tx and Rx, however i
can't get a fixed value. The value keeps on fluctuating.

From the help of Simulink, it says that if the delay value fluctuates
means that i have to set the windowing value of the Find delay block
to a higher value. However, i've tried various values of windowing,
up to 1000 yet i still can't find the correct delay value to be
inserted into the error rate block...

Without the delay parameter, i'm getting incorrect error rates of up
to 0.5

Please help!!

This is a image of the BPSK model.
http://img393.imageshack.us/img393/7062/bpsk4ek.th.jpg

Q2:

In a simple QAM simulation. I am using a Bernoulli Binary Generator
to generate frames of 32 bits. These frames are then connected to a
Rectangular QAM modulator block with M set to 16. What kind of
normalization method should i use? There is min. distance between
symbols, average power and peak power.

The block description in the help doesn't contain much info.

And, what is the difference btwn the General QAM block and the
Rectangular QAM block?