Comments on: Eye diagram with raised cosine filtering

By: Krishna Sankar

Krishna Sankar — Mon, 23 Jan 2012 00:25:54 +0000

@Theeksha: The presence of sampling time offset increases the error vector magnitude. Ideally we would like to sample at the maximum vertical eye opening, but in the presence of sampling time offset, we will drift away from the maximum eye opening window.

By: Theeksha

Theeksha — Sun, 15 Jan 2012 15:29:24 +0000

What is the effect of sampling time offset in the error vector magnitude? Does the sampling time offset react to changes in roll off factor?

By: Krishna Sankar

Krishna Sankar — Sat, 03 Apr 2010 22:59:53 +0000

@pravindra kumar: I have not discussed the BER with raised cosine filter case, however you can find the BER with rectangular filter at http://www.dsplog.com/2009/05/08/ber-with-matched-filtering/

By: pravindra kumar

pravindra kumar — Sat, 13 Feb 2010 15:51:22 +0000

please help me
i want code for ber for bpsk using raised cosine filter

By: Ad

Ad — Wed, 23 Dec 2009 05:05:20 +0000

Hi Krishna,
I have a question regarding the plot of eye diagram that you’ve shown.
You said its plotted for two symbols and the eye opening seems to be at
the center of the diagram(at completion of first unit interval). So is plotted
like half of previous bit,current bit and half of future ?

By: Krishna Sankar

Krishna Sankar — Sun, 08 Nov 2009 03:46:35 +0000

@Fahmi: With a sampling frequency of fs, we can ‘see’ frequencies from [-fs/2 to fs/2). Typically, we would want to control a bigger bandwidth compared to the original transmit sequence. Hence we do upsampling.

By: Fahmi

Fahmi — Tue, 03 Nov 2009 15:55:02 +0000

Hi Mr krishna ,
I don’t understand the utility of “upsampling the transmit sequence ”
what will happen if we did not add the zeros to the sequence ?
I wonder if there is some links clarifying this idea .
thank you very much.