symbol rate and sample rate

[nolsqn]

hi....is there any relationship between symbol rate and the sampling rate....first let me tell you wat i am doing ...i am generating 1000 data bits , 20 sync bit and 4 gaurd bit .........i am doing 16 qam ,symbol rate is 1200 ,samples per symbol 16 upconverting it to 1800hz sending it to DAQ 6251 at AO0 (samples to write 10k and sample rate at 10k) receiveing the signal back from AI0 (samples to read 10k and sample rate at 10k) mode is countinous. after receiving from daq down samples it again  to 1800hz with pass band 2400 , gives the complex waveform to fractional resample.vi with parameter desired sample rate (1200 x 16 = 19200 hz) then give the signal back to demodulate qam.vi but the problem i am getting is that i am not getting the correctconstellation and bit error rate is to high....so i was wondering what i was doing wrong ..is it the daq samplin rate or the fractional resample.vi that i am no using rigth.

[nolsqn]

anyone any suggestions ...any help..plz

[Anna_K.]

Hello,

Based on your description, I can see that you send the data through the Fractional Resample.vi, I just wanted to make sure that you apply this before outputting the data also? As well, after the fractional resample on the input side, do apply the same guard and sync bits to recover the data? For a comprehensive example on how to code this you can download our free Baseband Developer's Kit and take a look at the examples and tutorials. You may find it really helpful.

Look for it in the Downloads section. 

http://zone.ni.com/devzone/cda/epd/p/id/6071#toc1

Also, if wanted to post a screenshot of your code, or the code itself, it would be helpful for us as well.

Regards,

Anna K.