An implementation provides a system that includes: a control module including a first antenna, the control module configured to generate a first radio frequency (RF) signal and transmit the first RF signal using the first antenna； an implantable lead module including a second antenna and at least one electrode configured to stimulate excitable tissue of a subject； and a relay module configured to receive the first RF signal； generate a second RF signal based on the first RF signal, the second RF signal encoding a stimulus waveform to be applied by the at least one electrodes of the implantable lead module to stimulate the excitable tissue of the subject； and transmit the second RF signal to the implantable lead module
