Implementation and Experimental Results of OFDM-Based Superposition Coding

In theory, multi-user techniques such as Super-Position Coding (SPC) are known to improve throughput in wireless networks. However, in order to understand their practical limitations, it is imperative to actually implement and experiment with such techniques in a realistic setting. In this paper, the authors present the design of a software radio-based implementation of superposition coding using the GNU Radio architecture. They describe software and hardware issues associated with SPC implementation on a Universal Software Radio Peripheral (USRP) board. They then experimentally evaluate the performance of this SPC system and demonstrate how it compares to a Time-Division Multiplexing (TDM) system.