doc.: IEEE /0038r0 Submission March 2006 Victor Tawil, MSTVSlide 1 DTV Signal Captures IEEE P Wireless RANs Date: Authors: Notice: This document has been prepared to assist IEEE It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEEs name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEEs sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE Patent Policy and Procedures: The contributor is familiar with the IEEE 802 Patent Policy and Procedures including the statement "IEEE standards may include the known use of patent(s), including patent applications, provided the IEEE receives assurance from the patent holder or applicant with respect to patents essential for compliance with both mandatory and optional portions of the standard." Early disclosure to the Working Group of patent information that might be relevant to the standard is essential to reduce the possibility for delays in the development process and increase the likelihood that the draft publication will be approved for publication. Please notify the Chairhttp://standards.ieee.org/guides/bylaws/sb-bylaws.pdf Carl R. StevensonCarl R. Stevenson as early as possible, in written or electronic form, if patented technology (or technology under patent application) might be incorporated into a draft standard being developed within the IEEE Working Group. If you have questions, contact the IEEE Patent Committee Administrator at >

doc.: IEEE /0038r0 Submission March 2006 Victor Tawil, MSTVSlide 2 Presentation Outline Field Test Measurement Program DTV Signal Captures Use of DTV Signal Captures to Evaluate the Performance of the various Sensing Algorithms

doc.: IEEE /0038r0 Submission March 2006 Victor Tawil, MSTVSlide 3 Broadcasters Field Measurements ( ) Goal –Determine the coverage of the ATSC system relative to the existing analog –Evaluate the performance of the ATSC system under different reception conditions (i.e., multipath & noise conditions, etc.) –Compare the performance of different generation of receivers –Aid in the development a new propagation model or modify an existing one to more accurately predict the performance of the new digital service

doc.: IEEE /0038r0 Submission March 2006 Victor Tawil, MSTVSlide 4 Field Measurement Program Scope Measurements were made at low VHF, High VHF and UHF Collected more than 20,000 outdoor locations in 25 different markets in the US More than 5,000 indoor locations in 10 different markets

doc.: IEEE /0038r0 Submission March 2006 Victor Tawil, MSTVSlide 5 Findings Coverage of the ATSC DTV system is equivalent to the existing analog service under benign, static or slow varying multipath conditions A large number of complex multipath conditions encountered in the field were not demodulated by older and current generation DTV receivers. These conditions were difficult to simulate in the lab

doc.: IEEE /0038r0 Submission March 2006 Victor Tawil, MSTVSlide 6 PS-RG SB 6 MHz DTV DTV DTV

doc.: IEEE /0038r0 Submission March 2006 Victor Tawil, MSTVSlide 7 6 MHz DTV DTV NTSC

doc.: IEEE /0038r0 Submission March 2006 Victor Tawil, MSTVSlide 8 PS-RG SB 6 MHz DTV DTV NTSC

doc.: IEEE /0038r0 Submission March 2006 Victor Tawil, MSTVSlide 9 Ch. 6 Measurement - Charlotte, NC dB/div Frequency (MHz) Impulse Noise

doc.: IEEE /0038r0 Submission March 2006 Victor Tawil, MSTVSlide 10 Findings (continued) Development of a predictive model to determine the service reliability of an ATSC DTV system is not possible at this stage. A better quantification of the multipath conditions in the field is needed Conducting field measurements to compare The performance of different generation of DTV receivers are expensive. Need a more economical alternative.

doc.: IEEE /0038r0 Submission March 2006 Victor Tawil, MSTVSlide 11 Outline Field Test Measurement Program DTV Signal Captures Use of DTV Signal Captures to Evaluate the Performance of various Sensing Algorithms

doc.: IEEE /0038r0 Submission March 2006 Victor Tawil, MSTVSlide 12 ATSC A/74 Recommended Practice: Receiver Performance Guidelines The document lay out performance thresholds and testing procedures for DTV receivers to ensure reliable reception of digital television. Section 5.4 focus on multipath testing of receivers: Field capture Ensembles Field capture Ensembles Laboratory Ensembles Laboratory Ensembles

doc.: IEEE /0038r0 Submission March 2006 Victor Tawil, MSTVSlide 13 ATSC A/74 RF Field Ensembles A total of 50 RF field ensembles were selected from a group of 270 field ensembles collected in the Washington, DC urban areas and New York City. The selected ensembles represent difficult reception conditions (i.e. Challenging multipath conditions) –New York City 18 UHF field ensembles. All collected indoor –Washington, DC 32 UHF field ensembles. (22 indoor, 10 outdoor at 30 feet)

doc.: IEEE /0038r0 Submission March 2006 Victor Tawil, MSTVSlide 14 Description of Field Ensembles

doc.: IEEE /0038r0 Submission March 2006 Victor Tawil, MSTVSlide 15 A/74 Field Ensembles Data Format Each ensembles has a maximum length of up to 25 seconds DTV channels were sampled at Msample/sec and down converted to a low central IF frequency of 5.38 MHz A/D conversion of RF signal used a 12 bits A/D. Each sample was encoded into 2-byte word (signed Int l6 with a twos complement format) A total of 1.05G bytes were needed for a 25 second capture. Data is available on DVD free of charge through MSTV

doc.: IEEE /0038r0 Submission March 2006 Victor Tawil, MSTVSlide 16 Physical Support of Data Transfer To play back data, an RF player is required (Sencore 910, or Celerity player available on loan from MSTV)

doc.: IEEE /0038r0 Submission March 2006 Victor Tawil, MSTVSlide 17 Video

doc.: IEEE /0038r0 Submission March 2006 Victor Tawil, MSTVSlide 18 Outline Field Test Measurement Program RF Signal Captures Use of DTV Signal Captures to Evaluate the Performance of the various Sensing Algorithms

doc.: IEEE /0038r0 Submission March 2006 Victor Tawil, MSTVSlide 19 Sensing: Evaluation of Various Detection Algorithms Two basic requirements –Evaluation of various detectors should use actual RF signal conditions encountered in the field. Propose use of ATSC A/74 field ensembles – Computer simulation of various detection algorithms using A/74 field ensembles (or a subset of) is acceptable, provided that an independent third party verification of the results is included as part of the evaluation process

doc.: IEEE /0038r0 Submission March 2006 Victor Tawil, MSTVSlide 20 Use of Field Ensembles to Evaluate the various Sensing proposal Tiger Team develop a methodology and test suite Use the field ensembles or a subset of them as input to the sensing simulator Attenuate the signal using a noise generator Determine the appropriate statistics Noise Generator