Re: [Discuss-gnuradio] BER over air

[Mostafa Alizadeh]

Yeah,
If we have include the chanel the received symbol is:
y(t) = h(t) * x(t) + n(t).
So h can vary with time and isn't flat. In SNR we would know h. For simplicity I ignored it by setting h = 1 which is not acurrate.

On Dec 28, 2014 9:01 PM, "Marcus Müller" <address@hidden> wrote:

Hello Mostafa,

I've forgot to add that
"
> All nonlinear and time variant effects isn't just due to the channel
> but the RF hardware.
"
is usually not true -- again, SNR is signal to noise, and maybe your
signal undergoes correction, and I don't know if that is going to be
memoryless.
Far more importantly, real radio channels *are not* flat. They are
frequency-selective, and they are time-variant. In many (easier) cases,
you can consider the channel to be flat for your very limited bandwidth,
and you can consider it's properties (or at least the statistical
properties of these properties) to be stationary -- but if you're
serious about channel characteristics, you can't just say "my channel is
flat and time-invariant", without really saying why you can make these
simplifications.

Greetings,
Marcus