can't receive the sent IQ data at the receiver

[Airian]

hi

i am new to this community and NI 5640 R

i am using the card for the transmission of IQ array of 12880 elements in the array

I want to receive this array in the receiving VI. 

I am unable to receive this IQ array. I think i am not setting the parameters right?

parameters like IQ rate at transmitter and

IQ rate and samples to acquire at the receiver

I am using the sample VIs single tone generation and spectrum analyzer of NI 5640

made some changes in the spectrum analyzer VI to get IQ array

plz help me on this because my final project depends upon it

Best Regards

Imran Ul Haq

Air University Pakistan

[JerryAL]

Hi

I’ve posted another example that modulates and demodulates a PSK waveform in another posting.  It shows sending the waveform to the NI 5640R’s DAC and acquiring the NI 5640R’s ADC and then demodulating the data.  Due to a difference in phase between the NCOs in the DAC and the ADC, you will not see the exact same IQ samples that you generate on the receive side.

The Modulation Toolkit VIs use a Synchronization system for the receive side to determine the phase offset on the receive side and correct for that.  I recommend looking at the Modulation Toolkit example VI that this example is based upon for more information on synchronization.

The example’s post:
http://forums.ni.com/ni/board/message?board.id=ifrio&message.id=801#M801

Jerry

[Airian]

Hi Jerry sir,

Thx for your advice,i will try the PSK example as soon as i have LV8.5,Now i am working on LV8.2.1. I am implementing a QAM tranciever using the MT example QAM Tranciever.vi on NI 5640. 

The recieved constellation is fine now for the first time.

but my Rx bits have errors aproximatly 500 out of 1000 bits.i think this is because of synchronization issue between Tx and Rx as i am transmiting and recieving in the same vi both in while loops.what can i do now in this issue.

Also tell me about the significance of 'samples to aquire'.

Best regards,

Airian   

[Airian]

Hi,    Finally i am successful in transmiting OFDM fram using two IF 5640,one as TX and second as RX.    can any one done this before   can i publish a research paper tell me the steps best regards, Imran ul haq Air University,pakistan

07-08-2008 02:12 AM