University of Kansas KU Agile Radio Technology Gary J. Minden Electrical Engineering & Computer Science Information & Telecommunication Technology Center

University of Kansas KU Agile Radio Team Staff Dan DePardo Leon Searl Students A. Veeragandham R. Rajbanshi T. Newman J. Guffy R. Reed T. Short L. Pierce D. Trajkov F. Ted Weidling Qi Chen P. Krishnan V. Rory Petty D. Datla

University of Kansas Topics  Agile radios  A National Radio Networking Research Testbed  Future directions

University of Kansas Agile Radios  Flexible Hardware  Wideband RF Section (~ GHz)  Wideband baseband (several 10’s MHz)  Waveform: complex A/D and D/A driven  General purpose FPGA with logic and embedded CPUs  Linux based control processor

University of Kansas Agile Radios Enable  Dynamic service access  WiFi, AMPS, CDMA, GSM, FM radio, TV, land-mobile, …  Dynamic spectrum access  Sense use of the spectrum, use if unused  Spectrum markets  Rapid service creation

University of Kansas Agile Radio Policy Challenges  U.S. Government policy  FCC, NTIA, State, and international forums  National defense and national economic needs  Brokering protocols  Secured and robust  ‘Contract’ enforcement  Community rules  Challenged by UWB, DSS, FH  Various levels of interference impact  RF level, combinations, and throughput  Robust communications  Urban environments, coordination, covert, anti-jam  Traditional defense requirements  Exploitation of signal processing power  BLAST, STEP, STORM, …  Push toward Shannon limit

University of Kansas Agile Radio Investments  Radio technology, signal processing, protocols, mesh networks, self-organization, adaptability, disconnected operation, management structures, enforcement…  New policies to allow agile radio deployment  Development, experimental, and evaluation range

University of Kansas NSF Project Objectives  Develop and demonstrate high-performance digital signal processing (DSP) algorithms and components to generate and detect H-OFDM signals  Develop and demonstrate ultra-wideband radio frequency transmitters and receivers  Develop and demonstrate ultra-wideband antennas, power amplifiers, and low-noise receivers to support the H-OFDM system  Analyze, implement, and evaluate H-OFDM for communication systems  Determine how to recognize and organize H-OFDM systems into communications networks

University of Kansas Technical Approach  Adapt existing transmitter and receiver designs to implement a wideband, software defined radio  Implement high performance (sample rate and precision) A/D and D/A converters  Interface RF/digital sections to FPGAs and general purpose computers  Analyze Hyper-Orthogonal Frequency Division Multiplexing  Implement protocols for resource allocation and coordination

University of Kansas Typical Software Defined Radio Illustrates digitally controlled software radio

University of Kansas KUAgile Design Concept

University of Kansas KUAgile Battery Pack  Operate self-contained for three hours (40 A-Hr at 1.2 V)  Provide 3.3 V and 5 V power to the radio, separate supplies for the digital and RF sections  External power to extend the operating time of the radio or recharge the batteries

University of Kansas KUAgile Control Procesor  Five functions: radio control; signal processing; configuration management; adaptive algorithms; and interface with wired networks.  PowerPC 405; 32 MB of RAM; 32 MB of flash; 266 MHz; Ethernet  Linux OS (Kernel 2.4)  KUAR CP fully participates in a wired network with standard IP services

University of Kansas KUAgile Digital Board  Xilinx Vertex II Pro V20; 2 PPC 405 cores; 21K logic cells; 300 MHz operation  Analog Devices AD9777 DAC; I & Q; 160 Msps; 16-bit  Analog Devices AD6645 ADC; I & Q; 80 Msps; 14-bit  4 MB (1 M x 36-bit) SRAM

University of Kansas KUAgile 5 GHz RF Transceiver

University of Kansas KUAgile Tx/Rx Antenna Patch 5 GHz wideband integrated LNA receiver patch 5 GHz wideband (1 GHz) integrated patch computed pattern Preliminary performance measurements

University of Kansas KUAgile OFDM  Simulation of multiple carrier OFDM system in MatLab and conversion to C  Error correction code  BPSK, QPSK, and QAM supported  IFFT and FFT  Prefix and Postfix insertion  Pulse shaping  Timing and frequency shifts included; framing detection included  Design of 64-bin FFT in VHDL for Vertex II Pro device

University of Kansas A National Radio Networking Research Testbed (NRT)  A field deployed measurement and evaluation system  Long term radio frequency data collection  Facility for testing and evaluating new radios,  An accurate emulation/simulation system  Incorporate long-term field measurements for evaluating new wireless network architectures, policies, and network protocols, and  Experiments  Innovative wireless networks  Integrated analysis, emulation/simulation, and field measurements.

University of Kansas NRT Initial Research Questions  What are the characteristics of the wireless environment over a long time period and broad range of frequencies?  How should sensor networks be built and deployed to best measure the wireless environment?  How can the RF environment be sounded over a wide range of frequencies without interference and remaining within the constraints of government regulations?  How can the wireless measurements be mapped to accurate network-level simulation models?  How can the characterized RF environment be used for testing and evaluation of novel wireless systems?

University of Kansas NRT RF Data Collection  Long-term measurement of RF utilization  Spatial/Temporal  Noise floor levels (‘Interference Temperature’)  ~2 MHz - 6 GHz  Channel Sounding  Develop ‘quiet sounding’ using long, low-power density signals and signal processing techniques  Test and evaluation range  Measure behavior of actual prototype radios

University of Kansas NRT Database Objectives  Record “common” instrument settings  Record observation instances  Archive collected measurements

University of Kansas NRT Instrument Settings  Sweep Set  Analyzer Settings  Antenna Id  Analyzer Settings  Instrument Id  Start and End Frequency  Bandwidth resolution  Frequency step  Attenuation  Antenna Id  Type; Gain; Center Frequency; Bandwidth; Height

University of Kansas NRT Measurement Instance  Sweep Set Id  Organization Id  Start and Stop Time  Location (Latitude, Longitude, and Elevation)  Antenna azimuth and zenith

University of Kansas NRT Sweep Data  Actual Start and Stop time  Array of Frequency and Amplitude

University of Kansas NRT Collection Screen

University of Kansas NRT Repository Search  Search Repository based on:  Location  Time and Date  Frequency  Download  CVS format  Compressed format  Upload  NRT Format  “MatLab” Format

University of Kansas NRT Example Raw Data Original data plot (white is a more intense signal) 9 kHz - 32 MHz HF band 6 PM to 6 AM April 29, 2004 ~800 sweeps 10 kHz bandwidth

University of Kansas NRT Min/Max Signals Determine Min/Max/Avg signal per frequency

University of Kansas NRT PDF of Signals Determine occurrence of signal intensity

University of Kansas NRT Threshold Signals Threshold at 50% of PDF

University of Kansas NRT Utilization of Frequencies Utilization (>50% signal strength) per frequency

University of Kansas NRT Spectrum Analysis Challenges  Spectrum Analyzers miss dynamic spectrum use  Immense data collection problem  Location; Direction; Frequency; Time; Detection  Analysis techniques  Eliminate noise; Detect weak signals (e.g dBm); Detect intermittent signals

University of Kansas NRT Channel Sounding Approaches  RF Narrow Pulse  Difficult to generate  Frequency Domain Measurements  Consistent with Hyper-OFDM approach  PN Sequence

University of Kansas Future Directions  Configuring Software Radios  Adaptive Algorithms  Wireless Network Control  Innovative Receiver Designs

University of Kansas Generalized Channel Compression Error CtrlSpreadingModulationTransmit De-CompressError CtrlDe-SpreadDe-ModulateReceive Composite Channel Thermal Noise Mutual Interference Jamming Multipath Other Information Source Information Sink Encrypt Decrypt Every processing stage is programmable and controllable.

University of Kansas Radio Resource Space (ElectroSpace)  The RF Resource Space consists of  Frequency – the radio frequencies used to carry a signal  Time – the time duration a signal is transmitted  Space – the volume over which the signal transmission is effectively communicated or causes interference  Signal format – the manner in which information is encoded on the radio frequency signal RF Resource illustrating a few signals in time, frequency, and space. Frequency Time Space TDMA CDMA TV FM

University of Kansas Agile Radio Environment

University of Kansas Wireless Network Control  Radios coordinate operations across the network  Frequency management  ECC  Modulation  Spreading  …  Radios adhere to established policies  Radios adhere to operational constraints

University of Kansas Innovative Receiver Design  von Neumann processing becoming available to communications systems  Moore’s ‘law’ enabling significant processing capacity  New, iterative, algorithms need to be explored  Drive towards established theoretical capacity limits

University of Kansas KU Agile Radio Technology Gary J. Minden The University of Kansas Electrical Engineering & Computer Science Information & Telecommunication Technology Center