Help regarding to NI 5640R card + continouse signal generation

[sree_405]

 Hi,

This is Sreenivasulu.I am using LabVIEW 8.2 and hardware card NI 5640R version 1.1
I need to generate some modulated signal like 2-FSK,4-FSK,BPSK,QPSK,OOK and GMSK.
I generated all modulation using Modulation tool kit and Mathscript node except GMSK.But
the problem is i am unable to use lengthy bit stream.
My Fc=8.6M Hz,
   Baud rate =9600Hz,
   Fs=25Mhz
   No.of samples per symbol=25M/9600=2604
   Total number of samples=2604*24= 62496.


So, i can generate maximum 24 bit,because my memory block size is 65540 samples.
Now what here happening is that 65540(IQ)samples or less samples,what i send to memory
block,it will take that sample and it will generate continuously(means repetitively)with
that sample.Because of this i am unable to use more bits stream.

Here my issue is how i have to generate continuously with taking new set of samples into
memory block.

Please help me to solve these two issue,i am waiting for your reply.

 --
Thanks & regards
Sreenivasulu.O
Cell: +91-93948-22850

[NIRF-Group]

Hi Sreenivasulu,

Fs= 25MHz is very high. You should consider reducing this based on the samples per symbol you want to generate.
Also make sure that you have selected suitable parameters of the following equation.
• DAC_<i>_IQ_Clk = 2 × REFCLKDAC_<i> × Clock multiplierDAC_<i> / InterpolationDAC_<i>
                               = 2 × Symbol rate × Samples per symbol

Hope this helps!
--Vinay