Ultra-High Frequency Signal Transmission Based on Temporal Ghost Imaging

We propose a method based on temporal ghost imaging (TGI) that enables signal transmission at an ultra-high frequency much higher than the bandwidth of the emitter in a visible light communication (VLC) system. The signal is transmitted by a micro-LED at a frequency of up to 32 GHz, almost 600 times the 54 MHz micro-LED bandwidth. At such a high frequency, the directly transmitted signal is severely distorted and attenuated by bandwidth limit. However, based on the principle of TGI, we can recover the signal by correlating the power of the distorted signals and Hadamard modulation sequences. The linear transmission property of Hadamard spectrum density guarantees that, although bandwidth limit causes density loss, high frequency component of the signal can be reconstructed with high quality and reasonable recognizability. This work opens up a new path to pushing the signal transmission frequency beyond the bandwidth limit of the hardware, which could find meaningful applications in optical communication areas such as ultra-high frequency free-space optical communication, underwater wireless optical communication, and ultraviolet-C optical wireless communication.