>westocl wrote:
>>> westocl wrote:
>>>>> westocl wrote:
>>>>>> Hello all.
>>>>>>
>>>>>> Is it feasable to do an fft in 'real time' on different 'blocks
of
>>>> data?
>>>>>> (i understand the nomenclature real time may be inappropriate).
>>>>>>
>>>>>>
>>>>>> Im thinking, in general usage of an FFT, some x[n] comes in one
>> sample
>>>> at
>>>>>> a time and fills up a buffer and when that buffer (lets call i
128
>>>> time
>>>>>> domain samples) is filled a FFT is taken and the 'output' is 128
>> points
>>>> of
>>>>>> frequncy domain data.
>>>>>>
>>>>>> Now.. instad of somthing like a sliding DFT where a windo
evaluates
>>>> the
>>>>>> previous 127 samples along with one new one, i have a situation
>> where
>>>> i
>>>>>> want to give the 'fft buffer' 128 NEW data points... so ever
single
>>>> 'time
>>>>>> instant'...128 new x[n] data are available.
>>>>>>
>>>>>> If this were done would I get a new FFT output at every time
>> instant?
>>>>> You confused me. 128 new instances of x[n] for every n? How?
>>>>>
>>>>> Jerry
>>>>> --
>>>>> Engineering is the art of making what you want from things you can
>> get.
>>>>
>>>> You are right...My notation is somewhat confusing by using x[n].
But
>>>> imagine we had a switch that will switch to an already full buffe
at
>>>> every 'sample interval'. Then at the next instant we go to the next
>> 128
>>>> buffer and we call that x[n] and so on..
>>> What fills these nearly full buffers? When? You seem to want 128 new
>>> samples per sampling instant. That can't be sustained.
>>>
>>> Jerry
>>> --
>>> Engineering is the art of making what you want from things you ca
get.
>>
>>
>> It seems thats exactly the case i will have... What i want to do is
>> analagous to having 128 antennas and a situation where i have to tak
the
>> FFT for each antenna. So some kind of rotary switch gives me the new
>> antenna input data at every sample... and will keep spinning.
>
>There's nothing unusual about simultaneously processing multiple
>streams. But each stream would have it's own FT. There could be 128
>samples collected at each sample interval, but probably not via a
>multiplexer (rotary switch). One of us is still confused.
>
>Jerry
>--
>Engineering is the art of making what you want from things you can get.


Lets say you wanted to take the FFT of the output of a sliding DFT..
heres a situation where you will have new data at every sample.

Could this be done?