Experimental Demonstration of Approximate Communication Based on Radio-Over- Fiber Systems

The importance of multi-valued data transmission for improving communication throughput has become apparent with the explosive growth o communication and computing demands. Although modulation schemes with denser constellations can provide increased data rates, they require a higher signal-to-noise ratio. On the other hand, sparser constellation formats offer reliable communication thanks to their greater tolerance to noise, but the throughput is inferior to that with denser constellations. Here, we introduce an approximate computing/communication that involves the critical notion of quality of information to tolerate the trade-off between throughput and reliability, which will be important in future high-performance optical communications and interconnects. In this study, we experimentally demonstrate a dynamically configured transmission scheme where different modulation formats are adopted according to the importance of bit sequences on the basis of Radio-over-Fiber (RoF) systems in transmitting floating-point numbers. The proposed system demonstrated an increased gross throughput of at least 25.1%, while errors in the transmitted floating-point numbers were uniformly bounded.