BER PSK question

[sdada]

Hi 

I have a little problem, IM trying to make BER measurement in simple_psk_transreciver.vi file, which is in examples of modulation toolkit..

and it doesn't work... allways showing ber =1... 

Michael

[e2m0i0l7]

Dear Michael,

Please attach the VI as I could not find any similar in the examples from Modulation Toolkit - I am using version 4.2.1

Thank you,

Mircea

[sdada]

Please

[nolsqn]

i didnt hav time to see yours will do it tomorow but till then here is sumthin i was working a littler while back .

regards

[sdada]

Thank you, but I still dont understand why my simple implementation of BER measurment ... doesn't work...

[nolsqn]

there is nothing wrong in your simulation ... but i still donot get why are you getting BER = 1 ......

on reading the BER vi help i found this

condition : trigger not detected in the current input bit stream

BER out : 1.0

read help . I donot think you have any problem in VI ....as can be seen form the RX constellation plot that around 12 Eb/No the plot is very clear suggesting that the RX bit error approaches to 10e(-4)

regards

[e2m0i0l7]

Hi 

Please make a control for BER trigger with values between 0 and 1 and, while running, set the value for BER trigger until the led trigger found will light - BER measurement has been triggered.

Tell me how it works for you,

Mircea

[sdada]

Oh, I thought that default parameters will work fine, now im trying to setup this ber trigger  threshold and confidence, but it seems to doesn't work correctly... I think because I don't know what exactly they should be...

For example in this vi.

16-MSK = 8*60=960 total bits...

I was trying to make BER trigger threshold 0,5 0,4 0,6 and with NO! Noise impairments. Clean constellation plot -

BER shows 0,54 0,48 and other values.

No idea why...

[SteCla]

I have the same problem. Was this solved?

[JÞB]

Note also:

Here and here

That makes me wonder if all of them are in the same class in some university somewhere?  Treating this as if it was a student problem.  (Advice but they need to earn their own grades)

Often, filters are set for an initial supposition of zero.  The Modulation Toolkit is full of FIR filters!  At Times you need to filter the same signal twice!  Once to stabilize the response and once to properly filter the input.   HINT: take that IQ signal and display it in polar coordinates to see the FIR impulse ringing rho!

That being said! I would not expect novices to dig that deep into that TK!  Nice call shouting out to the forums on all cases!