samples per symbol Vs sampling rate - Can they be used interchangeably?

Hi,
Do samples per symbol and sampling rate convey the same message?

I know what sampling rate is but why samples per symbol is used in certain
cases instead of sampling rate?

I think that samples per symbol is used in systems where the signal is
processed at baseband whereas, sampling rate is used for systems where
processing is done at IF.

On 11/14/2010 09:50 AM, johnlovestohate wrote:
> Hi,
> Do samples per symbol and sampling rate convey the same message?
>
> I know what sampling rate is but why samples per symbol is used in certain
> cases instead of sampling rate?
>
> I think that samples per symbol is used in systems where the signal is
> processed at baseband whereas, sampling rate is used for systems where
> processing is done at IF.

Sampling rate is normally taken as the number of samples per _second_, 
and speaks to the ease of processing a signal of a given bandwidth, 
whether it has digital data encoded on it or not.

Sampling rate per _symbol_ speaks to the ease of demodulating a digital 
signal.

-- 

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html

"johnlovestohate" <aliatolemiss@n_o_s_p_a_m.gmail.com> writes:

> Hi,
> Do samples per symbol and sampling rate convey the same message?
>
> I know what sampling rate is but why samples per symbol is used in certain
> cases instead of sampling rate?
>
> I think that samples per symbol is used in systems where the signal is
> processed at baseband whereas, sampling rate is used for systems where
> processing is done at IF.

Sample rate (samples / second) is a characteristic of a sampled data
system (i.e., a digital system). Symbol rate (symbols / second) is a
characteristic of a digital communication system. Samples per symbol
arise when a digital communication signal is processed digitally, in
which case

  samples / symbol = (samples / second) / (symbols / second)
-- 
Randy Yates                      % "Though you ride on the wheels of tomorrow,
Digital Signal Labs              %  you still wander the fields of your
mailto://yates@ieee.org          %  sorrow."
http://www.digitalsignallabs.com % '21st Century Man', *Time*, ELO

"johnlovestohate" <aliatolemiss@n_o_s_p_a_m.gmail.com> writes:

> Hi,
> Do samples per symbol and sampling rate convey the same message?
>
> I know what sampling rate is but why samples per symbol is used in certain
> cases instead of sampling rate?
>
> I think that samples per symbol is used in systems where the signal is
> processed at baseband whereas, sampling rate is used for systems where
> processing is done at IF.

PS: Using the definitions previously given, sample rate is used for both
IF and baseband. Although not strictly true, typically we speak of
samples / symbol when dealing with a baseband digital comm signal that is
being processed digitally.

Also, samples / symbol is an important factor in digital demodulation as
it impacts the ability to equalize the signal and determine timing.
-- 
Randy Yates                      % "Rollin' and riding and slippin' and
Digital Signal Labs              %  sliding, it's magic."
mailto://yates@ieee.org          %  
http://www.digitalsignallabs.com % 'Living' Thing', *A New World Record*, ELO

ok. thanks