Hi, @hongzhaozheng ,
After consulting with one of our experts, this was the response:
The Intermediate Frequency (f_IF) is effectively ZERO in this case as the IQ data generated by Skydel through the “File” output type option is in the baseband. This means the client Software Receiver should process the IQ data generated by Skydel with f_IF = 0.
Hope this helps, and feel free to contact us again if you need more help.
AD