A Software Defined Radio Scheme for the Hierarchical Modulation Based Multimedia Broadcast System Using USRP

In this paper we build a Software Defined Radio (SDR) testbed for the mobile broadcast system which using hierarchical modulation based on the USRP (Universal Software Radio Peripheral) platform. In hierarchical modulation, two separate data streams are modulated into one single stream. One stream, called the "High Priority" (HP) stream is embedded within a "Low Priority" (LP) stream. In Multimedia Broadcast System, the multimedia source can be split into these two streams. The HP stream will guarantee basic visual effects and sound effects, while the LP stream offers a better performance. In order to verify the effect of hierarchical modulation applications in mobile multimedia broadcast system, the SDR testbed has been built. In SDR, the common basic communication procedures performed. The digital signal processing is done using computer, while actual transmitting and receiving process are carried out using the USRP board which can facilitate the development of PHY and MAC layers functionality. Then, we demonstrate the experimental platform with computer and the board. In particular, the implement will be visualized through video transmission.