DEF CON 23 - Wireless Village - Michael Calabro - Software Defined Radio Performance Trades & Tweaks
Channel: DEFCONConference
Date: 05/12/2015

This workshop is targeted at new and experienced software defined radio (SDR) operators, developers, and enthusiasts seeking a better end-to-end system understanding, and anyone looking to maximize their SDR’s performance. Commercially available SDRs (e.g. USRPs, RTL-SDRs, BladeRFs, etc) are commonly used to fuzz wireless interfaces, deploy private cellular infrastructure, conduct spectrum surveys, and otherwise interact with a wide variety of custom and commercial devices. This workshop focuses on the key parameters and performance drivers in SDR setup and operation that elevate these common platforms to the level of fidelity required to interact seamlessly with commercial devices and networks.

The workshop will begin by surveying different SDR hardware architectures and summarizing the performance tradespaces of several of SDR applications (e.g. collection/survey/transmit). Then the workshop will break down into three main content focuses:

Understanding SDR Hardware: Breakdown common RF frontend and receiver architectures. Identify and derive key performance parameters, and when they will bound performance. Topics covered will include: Noise figure calculation, internal amplification, Frequency selectivity, external RF chains, and noise sources.

Understanding SDR Platform Objectives: Collection, transmission, surveying, and other applications, each present unique challenges to SDRs and will be limited by different dimensions of SDR processing and/or setup configuration. Topics covered include: real-time processing, host buffering, sampling, guard-intervals, framework selection (GRC vs REDHAWK vs MATLAB vs custom), and frequency and time domain signal representation.

Optimizing and Improving Performance: Now that the hardware and platform trade space have been characterized, how do attendees meet and exceed the performance requirements of their application? We will present specific examples for several common platforms (RTL-SDR and USRP). Topics covered will include clock selection, ADC dynamic range, FPGA/SoC offloading, RFIC configuration, CIC filters, sampling, DC biases, antenna selection & pointing, host buffering / processing, and cost-performance trades.

Speaker bio: 
Michael Calabro is a Senior Engineer at Booz Allen Hamilton Engineering Services where he is a technical leader of the Communications Center of Excellence. He has worked on digital communication systems and software defined radios for 7+ years and holds an MSEE focused in wireless communications. He regularly consults as a subject matter expert on commercial, government, and custom communication standards and systems.