doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 1 Cognitive Radio System Testbed Demonstration Dr. Kyutae Lim Associate Director of Technology Georgia Electronic Design Center, Georgia Institute of Technology

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 2 Cognitive Radio Testbed Overview

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 3 Cognitive Radio Testbed Cognitive Radio Testbed was built in Georgia Electronic Design Center, Georgia Tech, Atlanta, GA. Perform the real time demonstration of various operations in CR system. Perform the industrial level of evaluation for PHY/MAG and Sensing Technologies. CR Testbed has flexibility in H/W and S/W. Testbed configuration and test procedure can be set by WG and Tiger team. We hope CR testbed to contribute for forging IEEE Standard.

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 4 DTV Sig Gen Vector Sig Gen AMP TV Antenna ADC : Data Acquisition Spectrum Analyzer Equipment Control Signal Generation Spectrum Sensing Component Control Display Control Received sig. Analysis Testbed Control : MATLAB 4 CH DAC Receiver Module Vector Signal Analyzer DTV Test Receiver Signal GenerationSignal Reception CR Testbed System Configuration

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 5 Photo of Cognitive Radio Testbed DTV monitor DTV monitor Main Control Main Control Rec. signal spectrum Rec. signal spectrum Constellation (OFDMA) Constellation (OFDMA) RF receiver module RF receiver module Vector signal analyzer Vector signal analyzer Spectrum Analyzer Spectrum Analyzer Vector signal generator Vector signal generator Broadcast sig. generator Broadcast sig. generator DAC/ADC/ Computer DAC/ADC/ Computer

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 6 System Specification NameSpecification SMU 200A Vector Signal Generator Dual RF path – A (100 kHz ~ 6 GHz), B (100 kHz ~ 3 GHz) I/Q baseband modulation bandwidth – 56 MHz FSQ 40 Vector Signal Analyzer RF input – 20 Hz ~ 40 GHz Standard – GSM/EDGE, FM, CDMA2K, Bluetooth, WLAN, WiMax SFU TV Signal Generator RF output – 100 kHz ~ 3 GHz Standard –Digital TV – ATSC, DVB-T/H/C/S, DMB-T, DIRECTV, T-DMB/DAB –Analog TV, Arbitrary signal Test stream generator Noise – AWGN, phase noise, impulsive noise Fading – static path, pure dopler, rayleigh, rice, const. phase Tuner RF input – 50 ~ 878 MHz IF out at 44 MHz / 6-MHz SAW filter can be bypassed NF: 8 dB / RF VGA gain control: -12 ~ 38 dB DAQ (ADC) PCI-interface Dual channel / 12-bit resolution Max. 400 MSample/sec Input Dynamic Range : 100 mV ~ 5 V DAC PCI-interface 4 channel / 12-bit resolution Max. 300 MSample/sec EFA TV Test Receiver ATSC/8VSB Demodulation

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 7 Demo.1 : Cognitive Radio System Concept Purpose : Basic CR operation principle Spectrum Sensing Co-existance of Incumbent and WRAN Interference mitigation Frequency agile operation

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 8 DTV Sig Gen Vector Sig Gen AMP TV Antenna ADC : Data Acquisition Spectrum Analyzer Equipment Control Signal Generation Spectrum Sensing Component Control Display Control Received sig. Analysis Testbed Control : MATLAB 4 CH DAC Receiver Module Vector Signal Analyzer DTV Test Receiver Signal GenerationSignal Reception Testbed Configuration: Demo.1

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 9 Spectrum Sensing (TV signals only)

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 10 WRAN Interferer (overlapped) WiMax signal used as WRAN

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 11 OFDMA Constellation / EVM OFDMA communication failed. No constellation. EVM does not meet the criteria

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 12 TVs-WRAN Co-Existence (WRAN in vacant channel)

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 13 OFDMA Constellation / EVM OFDMA communication working well. Good constellation. EVM meet the criteria

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 14 Dynamic Frequency Switching - I - New primary user signal into the WRAN channel -

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 15 OFDMA Constellation / EVM Communication failed.

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 16 Dynamic Frequency Switching - II - WRAN signal move to another vacant channel -

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 17 OFDMA Constellation / EVM Communication in work.

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 18 Demo.2 : Evaluation of Spectrum Sensing Technology Purpose : Verifying Various Spectrum Sensing Technologies Generating Spectrum Environment Energy Detection: MRSS Feature Detection: AAC

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 19 DTV Sig Gen Vector Sig Gen AMP TV Antenna ADC : Data Acquisition Spectrum Analyzer Equipment Control Signal Generation Spectrum Sensing Component Control Display Control Received sig. Analysis Testbed Control : MATLAB 4 CH DAC Receiver Module Vector Signal Analyzer DTV Test Receiver Signal GenerationSignal Reception Testbed Configuration: Demo.2

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 20 Dual Sensing Strategy (presented Mar 06) Energy Detection for wide band (Analog, RSSI, MRSS, FFT…) Begin Sensing Fine/Feature Detection for single channel End Sensing occupied? Y N MAC (Select single channel) FFTCSFD Field Sync Optimum Radiometer Multi-cycle Detector AAC Spectral Correlation Spectrum Usage Database (BS) ATSC Segment Sync

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 21 Input Signal Spectrum / Time-domain Waveform

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 22 Coarse MRSS

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 23 Fine MRSS with Threshold Detection

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 24 AAC for OFDM (WLAN a) Get two clues (due to short and long preamble) !!

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 25 An Example of Scheduling Algorithm for DFH A WRAN system maintains two channels (operating channel and candidate channel) If WRAN BSes can communicate each other to schedule the time switching to the candidate channel, collision can be completely avoided. –Even if collision occurs on the candidate channel, it is only in very short time (about quite time). WRAN A Channel 1 Channel 2 Channel 3 WRAN B

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 26 Demo.3 : Evaluation of protecting Incumbent user from WRAN signal Generation of various fading environment DTV Signal quality measurement in Fading Coexistence of DTV and WRAN Signal quality measure for DTV and WRAN

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 27 DTV Sig Gen Vector Sig Gen AMP TV Antenna ADC : Data Acquisition Spectrum Analyzer Equipment Control Signal Generation Spectrum Sensing Component Control Display Control Received sig. Analysis Testbed Control : MATLAB 4 CH DAC Receiver Module Vector Signal Analyzer DTV Test Receiver Signal GenerationSignal Reception Testbed Configuration: Demo.3

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 28 ATSC Test 1 – Fading (1) ATSC with Fading channel environment ATSC –Ch. 39 (center freq: 623 MHz) –Level: -10 dBm –Fading Rayleigh (Pass loss: 3 dB, freq ratio = 1.00) EASY3 for DTV test Number of DTV signals and Fading parameters can be easily adjusted

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 29 ATSC Test 1 – Fading (2)

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 30 Signal quality can be measured ATSC Test 1 – Fading (3)

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 31 ATSC Test 1 – Fading (4)```````````````````````````````````````````````````````````` ````````````````````````````````````````````````````` Various graphs enables signal quality analysis for DTV signal

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 32 ATSC Test 2 – w/ WiMax (1) ATSC with Fading plus OFDMA signal to the adjacent channel ATSC –Ch. 39 (center freq: 623 MHz) –Level: -10 dBm –No fading WRAN (WiMax signal is used) –Freq: MHz, BW: 7 MHz –Level: 0 dBm

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 33 ATSC Test 2 – w/ WRAN (2) Spectrum WiMax ATSC WiMax Mask

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 34 ATSC Test 2 – w/ WRAN (3)

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 35 Signal quality is little bit degraded due to OFDM signal at adjacent channel ATSC Test 2 – w/ WRAN (4)

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 36 ATSC Test 2 – w/ WRAN (5) OFDM signal

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 37 ATSC Test 2 – w/ WRAN (6) OFDM (WiMax) performance Still OK!

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 38 Summary CR Testbed has built in GEDC, Georgia Tech –Maximum H/W flexibility –Full S/W control: MATLAB –Easy to expand for evaluating Sensing, Interference, MAC, PHY … CR Testbed has been demonstrated –CR Concept and frequency agile operation –Spectrum sensing technology evaluation –Emulation of various fading channel environment –Evaluation of WRAN signal to interfere DTV reception

doc.: IEEE /0076r0 Submission Kyutae Lim, Georgia Tech May 2006 Slide 39 Suggestion Realistic spectrum environment can generated repeatedly. The testbed can be customized to perform various test/evaluation. The parameters and figure-of-merit can be defined by WG. Standard procedure for evaluation can be defined by WG. Lets use this testbed for standard evaluation platform for PHY and Sensing technology !!!