Smart Radio: Spectrum Accessfor First Responders
Sponsored by: Center for Wireless Telecommunications (CWT)and SDR Forum
Mark D. Silvius, Terry Brisebois, Chen Chen, Qinqin Chen,Feng Andrew Ge, Bin Le, Paco Garcia Rodriguez,
Tom W. Rondeau, Ying Wang, Alex Young, Charles W. Bostian
#23
2007June 6-8Wireless Personal Communications Symposium
The Challenge• Spectrum Access for First Responders
– A large city experiences a major, crippling earthquake– Total loss of previously existing communication infrastructure– First Responders must stand up a makeshift command post and
establish a temporary communication infrastructure
• Problem– Find available spectrum within a pre-defined band– Rendezvous with an intended receiver– Transmit data over that band with a pre-determined Quality of
Service (QoS) in urban conditions
• System Goals– Mobile and User Friendly– Sense and Classify Environment– Interoperate with other Smart and FRS Radios– Operate in Master-Slave or Infrastructures modes– Adhere to FCC Spectrum Regulations
Proposed Solution “Smart Radio” Design
RF Front End
Tx
Rx
Master Control
Signal Detector
Whitespace Information
Signal Info
Waveforms
Link Control
Decision Making
Source
Sink
Codec
VoiceCSVD
Data
SourceCoding
ChannelCoding
FRS Radio and Smart SDR Signature Database
Status
QoS Desired
Intended Recipient(s)or Channel
Have FRS compliant spectral properties
Dynamically change channels, with no service loss
Must interoperate with legacy FRS users
Ability to dynamically switch QoS settings
Will not produce interference to any other active communications traffic
Operate in a master-slave mode, or infrastructure mode
Source & destination radios must be able to rendezvous
19.2 kbps using 8-PSKRate ½ convolutional channel code
16 kbps using QPSKReed-Solomon channel codingCVSD vocoded voice,
Demonstrate at least 2 QoS settings
Cognitive transceiver25 kHz bandwidth5 MHz FRS Band (462 to 467 MHz)
Have FRS compliant spectral properties
Dynamically change channels, with no service loss
Must interoperate with legacy FRS users
Ability to dynamically switch QoS settings
Will not produce interference to any other active communications traffic
Operate in a master-slave mode, or infrastructure mode
Source & destination radios must be able to rendezvous
19.2 kbps using 8-PSKRate ½ convolutional channel code
16 kbps using QPSKReed-Solomon channel codingCVSD vocoded voice,
Demonstrate at least 2 QoS settings
Cognitive transceiver25 kHz bandwidth5 MHz FRS Band (462 to 467 MHz)
Methodology:– Utilize modular approach for system
conceptualization, design, and implementation
– Primary functions partitioned into smallerself-contained blocks
Table of Requirements
System Block Diagram
RF Front End
• Utilizes the sponsor’s SDR platform for transmit and receive
• Utilizes the SDR platform’s on-board digital filtering capabilities
USRPUSRP Lyrtech SFFLyrtech SFF
Antenna
LNA/Power Amp
Band-passFilter
X
Base-bandMixer
Band-passFilter
WaveformGeneration
= Front End
= Data Source
Antenna
LNA/Power Amp
Band-passFilter
X
Base-bandMixer
Band-passFilter
WaveformGeneration
= Front End
= Data Source
Antenna
LNA Band-passFilter
X
Base-bandMixer
Band-passFilter
WaveformRecovery
= Front End
= Data Sink
Antenna
LNA Band-passFilter
X
Base-bandMixer
Band-passFilter
WaveformRecovery
= Front End
= Data Sink
Hardware Front Ends – Customized for SR and FRS Radio Systems
FRS #1
FRS #2
SR #1 and #2
Signal Detection &Classification (SD&C)
• Characterizes the environment, so that the MC can decide in what vacant frequency ranges to establish a new links– Scans through the authorized frequency range and looks for
unused spectrum to establish a new radio channel
– Searches through the authorized frequency range for actively used spectrum
Spectrum Scanning / Energy Detection SD&C Smart Receiver and Interfaces
FRS Database• FRS database accepts a channel number as input and
generates an XML file that specifies the waveform associated with the channel
• MC block can poll the FRS database for Signal Classification
FRS Database Table FRS Channel Selection
RF WaveformWaveform RepresentationFRS Channel
Selection
RF WaveformWaveform Representation
Master Control (MC)• Dynamically adjusts SDR’s power, frequency, waveform,
CODEC, and QoS configuration settings in real-time
• Directs Spectrum Scanning, Smart Radio Rendezvous, Channel Change Protocol, and maintenance of dynamic data links
MC Module – Waveform Control Rendezvous Beacon Strategy
FRS #1 FRS #2 SR Node #1SR Node #1
SR Node #2SR Node #2
Channel Change Protocol
Ch. A Ch. BMasterNode
CODECS• Transform analog voice waveform into the a digital bit
stream and vice versa using the CSVD format
• Performs Reed-Solomon and ½ Convolutional Channel Coding for digital data streams
• Automatically determine if the input from the user is analog voice signal or a digital data signal
CVSD Decoded Voice WaveformCVSD Encoder Block Diagram
• Faculty Advisor:Dr. Charles W. BostianAlumni Distinguished Professor
[email protected], (540)-231-5096
• Team Leader:Mark D. SilviusPh.D. Student
[email protected], (540) 231-2558
• Sponsors:Center for Wireless Telecommunications
http://www.cognitiveradio.wireless.vt.edu/
SDR Forumhttp://www.sdrforum.org/
The Team
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