I think the question must be corrected as ksamples, or Msamples. It varies according to how many samples the system can process in real-time, modulation degree ($m$), and oversampling factor ($OS$). For digital communication systems, typically, receivers require more processing power when compared to transmitters. Therefore, the bottleneck will probably be caused by how complex your receiver is. For a basic setup (uncoded transmission), you can fetch the I/Q signal up to 5-10 Msample/sec. Assuming that you set your OS=4, you can roughly receive 1-2.5 Msymbols/sec. Secondly, for example, you use 8-PSK (each symbol conveying 3 bits), so the throughput (in an ideal case) is 3-7.5 Mbits/sec. Unfortunately, you should also insert some PHY frame headers as well as pilot sequences and time guards between the consecutive frames to accommodate a well-synchronized communication system. Therefore, the throughput may reduce by 20%.