Re: two questions about the general communication system

Thank you! What i am trying to do is very simple: I don’t use USRP, i
just used a vector as a bit source and have it modulated and transmitted
through a noise channel (on my laptop ^.^ ). Now i can set the value of
noise’s amplitude, but there seems to be no way to determine the bit
energy! How to get it? Thank you!!!


----- Original Message ----
From: Daniel H. [email protected]
To: Brian P. [email protected]
Cc: Bill S. [email protected];
[email protected]
Sent: Sunday, April 13, 2008 8:18:14 PM
Subject: Re: [Discuss-gnuradio] two questions about the general
communication system

Hash: SHA1

On Apr 13, 2008, at 1:28 PM, Brian P. wrote:

On Sun, Apr 13, 2008 at 2:38 PM, Bill S.
[email protected] wrote:

Thank you George!

I am just wondering when we calculate BER, how can we determine the
value of
bit energy? Thank u!

If you look through the relevant emails on the list, it seems no one
really understands the translation between the short values from the
USRP and absolute energy — ADC and processing behavior complicate
the issue. However, it is much easier to estimate the ratio of Signal
to Noise — this is a relative quantity. Just figure out receiver
power in the absence of a signal and in the presence of one…

  • -Dan
    Version: GnuPG v1.4.8 (Darwin)


So… if the noise channel is on your laptop, you must have generated
this channel? Is it a simulated channel? Are you specifying the noise

You’re not giving us much information.

  • George