Re: [Discuss-gnuradio] Clarification regarding Sample width in USRP.

[Martin Braun]

On 03/02/2014 06:04 AM, Manu T S wrote:
> Marcus,
> 
> Thanks..
> 
> Few more things.
> 
> Is it correct to assume that In the wiretype, complex intx(x = 16 or 8)
> means that each I sample is represented by x bits, and Q sample is
> represented by x bits?

Yes, e.g. sc16 -> 16 bits for I and Q, respectively == 32 bits / sample.

> What does the input type and output type in usrp sink and usrp source
> respectively, in GNU radio companion convey?

This is the type used in the flow graph. You usually want complex float
32, which is the standard GR complex type. Complex int 16 would be the
same as sc16 for the wire format (i.e., we don't convert).

M

> 
> Manu
> 
> 
> 
> On Sun, Mar 2, 2014 at 9:32 AM, Marcus D. Leech <address@hidden
> <mailto:address@hidden>> wrote:
> 
>     On 03/01/2014 11:00 PM, Manu T S wrote:
>>     Hello Everyone,
>>
>>     From little bit of googling I understood that there are different
>>     sample width possible in USRP. If my understanding is correct, we
>>     can use 16/8 bit sample width.
>>
>>     But my usrp block in GNU Radio lists complex float32 and complex
>>     int16, and VITA word 32 as the types.
>>
>>     How can we relate this with the 16/8 bit sample width?
>>
>>     From my understanding the complex data type in GNU Radio uses
>>     interleaved float32. So does the driver on the host machine
>>     convert the incoming data from its sample width to the one we want
>>     to the upstream blocks?
>>
>>     -- 
>>     Manu T S
>>
>>
>>     _______________________________________________
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>     You're looking for the "wire format" parameter in the UHD source/sink.
> 
>     UHD converts the wire-format into the floating-point format used
>     within Gnu Radio.
> 
> 
> 
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> 
> 
> 
> -- 
> Manu T S
> 
> 
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