Software Defined Radio Laboratory

Overview

Software Defined Radio Lab

The Software Defined Radio (SDR) Laboratory at Iowa State University was established in summer 2009, with partial funding from university EFTF funds. The lab has 12 universal software radio peripherals (USRPs), each of which interfaces with a desktop computer via an USB interface. Each radio has the capability to communicate in various frequency bands ranging from hundreds of megahertz to a few gigahertz.

The lab is used for both research and teaching. Researchers are currently establishing a wireless network coding test bed using the SDRs and also are using the radios for spectrum sensing and eventually developing cognitive radio networks.

Various senior design groups use the lab and researchers have used the lab for outreach efforts to members of underrepresented groups. In the future, researchers plan to introduce various SDR based components in junior and senior level courses at Iowa State.

Location
  • 3126 Coover Hall

Faculty

  • Aditya Ramamoorthy
  • Zhengdao Wang

About Software Defined Radio

Wireless communication systems usually consist of a radio-frequency (RF) front-end used for transmitting/receiving a signal at the appropriate frequency and a back-end that performs various signal processing tasks such as filtering and noise reduction. Such systems traditionally tend to have a tightly coupled front-end and back-end (i.e. there was dedicated hardware built for the signal processing part and it was usually tightly-coupled with the front-end). In recent years, with the advent of fast and low-cost computers it has become feasible to consider performing most of the signal processing in either software or on reconfigurable hardware, such as FPGAs.

A software defined radio (SDR) is an RF system that attempts to do as much of the signal processing as possible in software. In the ideal case, a signal is received, digitized, and sent to a computer where a program processes the signal into useful information. Similarly, on the transmission side, a computer would run software to generate a signal, the signal would be sent to some RF equipment attached to the computer that would convert the digitally modulated signal into an analog signal and transmit it.This allows the development of wireless communications systems without the constraints of developing specialized hardware. Given an RF front-end capable of converting the desired range of frequencies to and from raw digital samples at a rate useful to the computer, any sort of signal processing that can be programmed on the computer can be used for receiving and sending RF signals. GPS, FM radio, HDTV, RFID, Wi-Fi, and more, can all be done from the same computer without any digital signal processing hardware specific to any particular scheme.

Developing, prototyping, and testing novel wireless communication systems can happen much more quickly without the need to design and fabricate hardware capable of doing the signal processing required.