Introduction to Communication Systems Using Software Defined Radio

Author: Mr. Eric Hamke, Mr. Anees Abrol, Dr. Ramiro Jordan // 12/04/2015

The students at the University of New Mexico Electrical and Computer Engineering Department are using an integrated set of lectures and labs to better understand basic communications systems. The lectures are based on the textbook by Ziemer and Tranter, Principles of Communications - Systems, Modulation, and Noise.

The labs are written with the idea that the students not only need to make measurements, but also learn how to write their own Virtual Instruments (VIs) supporting the modulation schemes being studied. The first lab will include a demo where the USRPs are used to transmit and receive. The students will have a chance to setup the radios and gain experience with USRP interface Input/Output. The review will build on this experience to familiarize them with the standard lab interfaces used in the training. The review will culminate with having them modify and use the Spectrum Monitoring example provided with the LabVIEW USRP toolkit.

The other labs will build around a common interface and will have the students write their own modulation VIs. The students will then integrate their Modulation VIs into the standard interface that was developed or discussed in the review labs. The integration process will help the students become more advanced users as they need to plan and debug their application. The work involved in the resulting series of labs will be of increasing levels of difficulty. This approach is to ensure that the students do not spend excessive amounts of time on the labs and not learn the theory in class. The initial level will be structured such that the students are given an almost working AM modulation module and have to just debug it to get it to work. Essentially, using a working example, they would need to figure out what is missing and add it in. The next lab will have more elements missing and more discussion of what needs to be done. This will progress until the final lab where they will be given a description of what needs to be done, and they compose the final VI to accomplish the desire objective.

The labs are developed using the Universal Software Radio Peripheral (USRP). The choice of this radio provides 2 advantages from an instructional perspective: it minimizes the amount of lab equipment necessary for performing the labs, and its range of flexibility to support spectrum sensing, cognitive radio and alternate modulation schemes.

// Project Files

Please note that in order to view Instructor Only content you will need an instructor's account. First register for a general account and then request instructor access.