High-rate turbo equalization modem on GNU Radio and USRP

High-rate data communication is defined in relation to the available bandwidth. In some particularly wireless applications this bandwidth is only limited to voiceband, making high-rate links (traditionally above 2400 bits per second) very challenging using practical waveforms. Turbo equalizers perform well in the receiver part of such modems, with a fundamental weakness of complexity. In this paper, we propose some simplifications to make these great receivers more feasible in these channels. Additionally, software-defined radio (SDR) is chosen to implement the modem as a real-world radio system with the GNU Radio and USRP as its software and hardware platforms, respectively. Test results show that the proposed methods can dramatically decline the main complexity and they also include the performance of a typical modem in a standard channel model.