I am using fmcomms1 for a school project. For this project the latency from the transmitter-> ad9122 -> DAC ... -> ADC -> ad9643 is very important for our design, and this latency should be stable.
Currently, we are using cross-correlation and trying to synchronize the transmitted digital baseband signal with the sampled signal by ADC in FPGA.
However, it seems that the delay calculated by the cross-correlation is varying always. Is this due to the fifo inside ad9122 or ad9643 ip core? If so, is there a way to let the ad9122 transmitt the digital baseband signal directly without buffering it? and same for the ad9643's fifo/buffer.
Figure below shows the structure of our design.
Thanks a lot, it is really urgent.