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Subject to change
Figure 8: IQ data, transmitted as a block or as a stream
Example 2: IQ data captured with NRA
A 16QAM signal is also used here as an example of how the IQ data are
captured using the NRA.
Transfer of the data to a PC can be done in
block mode
using the
“Scope-Demo” demo program or by direct access through a remote
interface. The NRA sends the data over the remote interface following a
request.
To get started quickly, it is a good idea to use the demo programs. You
can set up the NRA directly from the “Scope-Demo” program and export
the IQ data blocks as .csv or .wav files. To help you get started with
programming, as well as referring to the
Command Reference Guide
,
you can activate the Communication Log, which records all the
commands sent from the demo program to the NRA. Once you have set
the parameters and recalled the data with the demo, you can read out
the commands needed for this from the log file. Communication can
then take place using these commands with a terminal program. You
can then integrate the entire communication and evaluation into your
own application. You can see from figure 8 that each IQ block must be
requested individually by the PC in block mode.
In
streaming mode
, the NRA communicates with the PC via a remote
link and sends the IQ data as a stream over a stream link. Both links are
via a single physical interface. Once started, the NRA transmits IQ data
continuously over the stream link. Figure 8 shows that the PC sends
commands to the NRA over the remote link and the NRA also uses this
link to send responses to these commands to the PC. The NRA starts to
stream the IQ data over the stream link following the Start command
and continues until it receives the Stop command from the PC.
Communication and evaluation of the data typically takes place directly
from a client specific application.
Regardless of whether block or streaming mode is used, mainstream
software such as RadioInspector or the Satellite Link Planner from
Inradios can be used to transfer the IQ data to the PC and evaluate
them from within the software.
PC
USB/LAN
NRA
Block mode
PC get IQ data NRA
return IQ block 1
get IQ data
return IQ block 2
Streaming mode
PC start IQ stream NRA
OK
IQ data
IQ data
IQ data
IQ data
stop IQ stream
OK
Remote link
Stream link
