The JHU/ECE Software Radio Prototyping Laboratory

The Concept

The Laboratory











What is (a) software radio?

Consider a radio receiver.  It performs two kinds of operations on received signals:  (1) conditioning the signals into a form suitable for conveying them to a destination, and (2) processing the signals to extract information.  Signal conditioning is performed by hardware that filters the signal to remove extraneous noise; amplifies it; and digitizes it for subsequent computer processing.  These are necessary, but preparatory, to the extraction of information.


Processing the signals in a software radio system is performed by computer software, typically on a standard computer running a widely available operating system.  Everything done in any kind of radio receiver which helps to extract information (i.e., play music) is performed in computer software.



Why is software radio useful?


The goal of a Software Radio is to implement nearly all components typically found in a radio in software by “getting code as close to the antenna as possible”. This allows for near limitless communications schemes to be implemented on a single radio hardware platform. Additionally, it allows for rapid prototyping by eliminating much of the costs traditionally involved in radio design.


Some tasks are unsuitable for software implementation due to their requisite computational complexity or physical constraints, and a tradeoff must be made based on the desired level of system flexibility.  (Patrick Mulligan, 2006)


Who uses software radio?


Software radio is an efficient platform for prototyping a family of radio sets built upon a common hardware architecture.  Such applications are important in both defense and commercial applications.

In another application, amateur radio operators, who used to build their own equipment before the VLSI era, now continue to enjoy hands-on radio experimentation via programmable radio.


Users of SW radio technology include

1.     The DoD

2.     Ham radio experimenters

3.     Wireless system designers

a.      Aspex

b.     FPGA

4.   There are more.  Stay "tuned!"