# (no subject)

**URL:** <https://www.ruby-forum.com/t/no-subject/232073>\
**Category:** GNU Radio\
**Created:** [September 16, 2014, 11:52pm UTC](https://www.ruby-forum.com/t/no-subject/232073 "2014-09-16T23:52:01Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![addis\_a](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/c4cdca/32.png) [@addis\_a](https://www.ruby-forum.com/u/addis_a)\
**Post date:** [September 16, 2014, 11:52pm UTC](https://www.ruby-forum.com/t/no-subject/232073/1 "2014-09-16T23:52:01Z")

</div>

Hi,  
I am working on a USRP project. I am using a USRP N200 with a BasicRX  
daughter board to perform data streaming. I am using GRC 3.6.4.1 on a  
Ubuntu 12.04 machine. The USRP N200 is set to have a decimation factor  
of 8  
to achieve a streaming rate of 12.5 MSPS, the daughter board is set to  
A:A  
to perform single channel real sampling. The I Q data wire format is set  
to  
be 16 integer each, and the host data format is set to be complex float  
32.  
The settings above are also in the attachments. For analyzing data, I am  
using Matlab R2013b on Windows 7. My question is: when I am streaming  
data  
for about 10 seconds, I am getting a file around 500,000,000 bytes which  
is  
reasonable ((16 bits/sample I+16 bits/sample Q)\*(10 seconds)_12.5  
MSPS_(1/8  
bytes/bits)=500 Mbytes), but when I use read\_complex\_binary.m provided  
by  
GNUradio to read the file in Matlab, I am only getting half of the  
expected  
samples (~62,500,000 samples) instead of 125,000,000 samples. Could  
anyone  
please explain why this is happening? Doesn’t 16 bits I and 16 bits Q  
wire  
format give me 32 bits per sample? Any help would be appreciated.