NTIA Report TR-05-429 

Interference Potential of 

Ultrawideband Signals 

Part 2: Measurement of Gated-Noise Interference to 

 C-band Satellite Digital Television Receivers 

Michael Cotton 

Robert Achatz 

Jeffery Wepman 

Paul Runkle 

NTIA Report TR-05-429 

Interference Potential of 

Ultrawideband Signals 

Part 2: Measurement of Gated-Noise Interference to 

 C-Band Satellite Digital Television Receivers 

Michael Cotton 

Robert Achatz 

Jeffery Wepman 

Paul Runkle 

U.S. DEPARTMENT OF COMMERCE 

Carlos M. Gutierrez, Secretary 

Michael D. Gallagher, Assistant Secretary 

for Communications and Information 

August 2005 

iii

DISCLAIMER 

Certain commercial equipment, software, and materials are identified in this report to specify the 

technical aspects of the reported results. In no case does such identification imply 

recommendation or endorsement by the National Telecommunications and Information 

Administration, nor does it imply that the material or equipment identified is necessarily the best 

available for the purpose.

v

CONTENTS 

Page 

1. INTRODUCTION ...................................................................................................................... 1 

1.1. Experiment.........................................................................................................................................2

1.2. Organization of Report ......................................................................................................................3

2. DTV SUSCEPTIBILITY TO GN INTERFERENCE ................................................................ 4 

2.1. Gating Parameters..............................................................................................................................4

2.2. Signal Powers and DTV Signal Quality Metrics...............................................................................4

2.3. DTV Signal Quality as a Function of Interference Average Power ..................................................5

2.4. DTV Susceptibility and FEC Performance as a Function of Interference Fractional On-Time ......10

3. CHARACTERIZATION OF GN SIGNALS ........................................................................... 16 

3.1. Temporal Analysis...........................................................................................................................16

3.2. Amplitude Analysis .........................................................................................................................18

3.3. Spectral Analysis .............................................................................................................................22

4. CONCLUSION......................................................................................................................... 25 

5. ACKNOWLEDGMENTS ........................................................................................................ 28 

6. REFERENCES ......................................................................................................................... 29 

APPENDIX A: EXTENSION OF EXPERIMENT TO GN(MB) SIGNALS.............................. 31 

A.1. DTV Susceptibility to GN(MB) Interference .................................................................................32

A.2. Characterization of GN(MB) Signals .............................................................................................39

APPENDIX B: VERIFICATION OF SUSCEPTIBILITY RESULTS........................................ 42 

B.1. Test System Overview ....................................................................................................................42

B.2. Signal Calibration ...........................................................................................................................43

B.3. Measured DTV Signal Quality .......................................................................................................45

B.4. Theoretical DTV Signal Quality for Gaussian Noise Degradation.................................................48

B.5. Validation of Measured DTV Quality Metrics for Gaussian Noise Degradation ...........................50

APPENDIX C: THEORETICAL ANALYSIS OF GATED GAUSSIAN NOISE...................... 53 

C.1. Amplitude Probability Distribution ................................................................................................53

C.2. Power Spectral Density...................................................................................................................55

APPENDIX D: CHARACTERIZATION MEASUREMENTS................................................... 58 

D.1. Measurement Setup ........................................................................................................................58

D.2. Results ............................................................................................................................................59
vi

FIGURES 

Page 

Figure 1. Simulated gated-noise signal, GN-10 ......................................................................4 

Figure 2. SNR, SNR′, INR, INR′, BER, and SER reference points...........................................5 

Figure 3. SER versus INR for a DTV receiver operating at SNR = 9 dB and exposed to 

GN interference........................................................................................................7 

Figure 4. BER versus INR for a DTV receiver operating at SNR = 9 dB and exposed to 

GN interference........................................................................................................7 

Figure 5. SER versus INR for a DTV receiver operating at SNR = 12 dB and exposed to 

GN interference........................................................................................................8 

Figure 6. BER versus INR for a DTV receiver operating at SNR = 12 dB and exposed to 

GN interference........................................................................................................8 

Figure 7. SER versus INR for a DTV receiver operating at SNR = 15 dB and exposed to 

GN interference........................................................................................................9 

Figure 8. BER versus INR for a DTV receiver operating at SNR = 15 dB and exposed to 

GN interference........................................................................................................9 

Figure 9. Illustration of threshold-of-visibility metrics.........................................................10 

Figure 10. INRTOV versus 10log(1/ζ) for a DTV receiver operating at SNR = 9 dB and 

exposed to GN interference ...................................................................................12 

Figure 11. BERTOV versus 10log(1/ζ) for a DTV receiver operating at SNR = 9 dB and 

exposed to GN interference ...................................................................................12 

Figure 12. INRTOV versus 10log(1/ζ) for a DTV receiver operating at SNR = 12 dB and 

exposed to GN interference ...................................................................................13 

Figure 13. BERTOV versus 10log(1/ζ) for a DTV receiver operating at SNR = 12 dB and 

exposed to GN interference ...................................................................................13 

Figure 14. INRTOV versus 10log(1/ζ) for a DTV receiver operating at SNR = 15 dB and 

exposed to GN interference ...................................................................................14 

Figure 15. BERTOV versus 10log(1/ζ) for a DTV receiver operating at SNR = 15 dB and 

exposed to GN interference ...................................................................................14 
vii

Figure 16. Simulated gated-noise signals with the same average power ................................15 

Figure 17. Illustration of pulse duration and pulse interval ....................................................16 

Figure 18. Illustration of burst duration and burst interval .....................................................17 

Figure 19. APDs of GN signals with τon = 10 ns band-limited to BDTV ....................................19 

Figure 20. APDs of GN signals with τon = 100 ns band-limited to BDTV ..................................19 

Figure 21. APDs of GN signals with τon = 1,000 ns band-limited to BDTV ...............................20 

Figure 22. APDs of GN signals with τon = 10,000 ns band-limited to BDTV .............................20 

Figure 23. Illustration of P/A for GN-10 band-limited to BDTV................................................21 

Figure 24. PSDs of GN signals with τon = 10 ns .....................................................................23 

Figure 25. PSDs of GN signals with τon = 100 ns ...................................................................23 

Figure 26. PSDs of GN signals with τon = 1,000 ns ................................................................24 

Figure 27. PSDs of GN signals with τon = 10,000 ns ..............................................................24 

Figure 28. INRTOV versus P/A for a DTV receiver operating at SNR = 9 dB and exposed to 

GN interference......................................................................................................26 

Figure 29. INRTOV versus P/A for a DTV receiver operating at SNR = 12 dB and exposed to 

GN interference......................................................................................................26 

Figure 30. INRTOV versus P/A for a DTV receiver operating at SNR = 15 dB and exposed to 

GN interference......................................................................................................27 

Figure A-1. Simulated gated-noise signal, GN(MB)-03 ...........................................................31 

Figure A-2. SER versus INR for a DTV receiver operating at SNR = 9 dB and exposed to 

GN(MB) interference.............................................................................................33 

Figure A-3. BER versus INR for a DTV receiver operating at SNR = 9 dB and exposed to 

GN(MB) interference.............................................................................................33 

Figure A-4. SER versus INR for a DTV receiver operating at SNR = 12 dB and exposed to 

GN(MB) interference.............................................................................................34 

Figure A-5. BER versus INR for a DTV receiver operating at SNR = 12 dB and exposed to 

GN(MB) interference.............................................................................................34 
viii

Figure A-6. SER versus INR for a DTV receiver operating at SNR = 15 dB and exposed to 

GN(MB) interference.............................................................................................35 

Figure A-7. BER versus INR for a DTV receiver operating at SNR = 15 dB and exposed to 

GN(MB) interference.............................................................................................35 

Figure A-8. INRTOV versus 10log(1/ζ) for a DTV receiver operating at SNR = 9 dB and 

exposed to GN(MB) interference...........................................................................36 

Figure A-9. BERTOV versus 10log(1/ζ) for a DTV receiver operating at SNR = 9 dB and 

exposed to GN(MB) interference...........................................................................36 

Figure A-10. INRTOV versus 10log(1/ζ) for a DTV receiver operating at SNR = 12 dB and 

exposed to GN(MB) interference...........................................................................37 

Figure A-11. BERTOV versus 10log(1/ζ) for a DTV receiver operating at SNR = 12 dB and 

exposed to GN(MB) interference...........................................................................37 

Figure A-12. INRTOV versus 10log(1/ζ) for a DTV receiver operating at SNR = 15 dB and 

exposed to GN(MB) interference...........................................................................38 

Figure A-13. BERTOV versus 10log(1/ζ) for a DTV receiver operating at SNR = 15 dB and 

exposed to GN(MB) interference...........................................................................38 

Figure A-14. APDs of single-dwell GN(MB) signals band-limited to BDTV ................................40 

Figure A-15. APDs of multi-dwell GN(MB) signals band-limited to BDTV .................................40 

Figure A-16. PSDs of single-dwell GN(MB) signals..................................................................41 

Figure A-17. PSDs of multi-dwell GN(MB) signals...................................................................41 

Figure B-1. Block diagram of DTV interference susceptibility test system .............................42 

Figure B-2. Block diagrams for calibration measurements.......................................................44 

Figure B-3. BER estimation circuit used by MPEG-2 stream monitor .....................................46 

Figure B-4. Simulation of BER estimation circuit used by MPEG-2 stream monitor ..............47 

Figure B-5. Theoretical DTV receiver performance versus SNR′.............................................49 

Figure B-6. Theoretical versus measured bit error rate performance of a DTV receiver .........50 

Figure B-7. Theoretical and measured BER for Gaussian noise interference...........................52 
ix

Figure B-8. Theoretical and measured SER for Gaussian noise interference ...........................52 

Figure C-1. Theoretical APDs of gated noise in BUWB ...............................................................57 

Figure C-2. Theoretical P/A of gated noise in BUWB...................................................................57 

Figure D-1. Setup for RF signal characterization measurements..............................................58 

Figure D-2. Simplified setup for IF signal characterization measurements..............................59 

Figure D-3. RF measurements of GN-01, Gaussian noise ........................................................62 

Figure D-4. IF measurements of GN-01 at INRTOV ....................................................................63 

Figure D-5. RF measurements of GN-02 (τon = 10 ns, ζ = 0.5000)...........................................64 

Figure D-6. IF measurements of GN-02 at INRTOV ....................................................................65 

Figure D-7. RF measurements of GN-03 (τon = 10 ns, ζ = 0.2500)...........................................66 

Figure D-8. IF measurements of GN-03 at INRTOV ....................................................................67 

Figure D-9. RF measurements of GN-04 (τon = 10 ns, ζ = 0.1250)...........................................68 

Figure D-10. IF measurements of GN-04 at INRTOV ....................................................................69 

Figure D-11. RF measurements of GN-05 (τon = 10 ns, ζ = 0.0625)...........................................70 

Figure D-12. IF measurements of GN-05 at INRTOV ....................................................................71 

Figure D-13. RF measurements of GN-06 (τon = 100 ns, ζ = 0.5000).........................................72 

Figure D-14. IF measurements of GN-06 at INRTOV ....................................................................73 

Figure D-15. RF measurements of GN-07 (τon = 100 ns, ζ = 0.2500).........................................74 

Figure D-16. IF measurements of GN-07 at INRTOV ....................................................................75 

Figure D-17. RF measurements of GN-08 (τon = 100 ns, ζ = 0.1250).........................................76 

Figure D-18. IF measurements of GN-08 at INRTOV ....................................................................77 

Figure D-19. RF measurements of GN-09 (τon = 100 ns, ζ = 0.0625).........................................78 

Figure D-20. IF measurements of GN-09 at INRTOV ....................................................................79 
x

Figure D-21. RF measurements of GN-10 (τon = 1000 ns, ζ = 0.5000).......................................80 

Figure D-22. IF measurements of GN-10 at INRTOV ....................................................................81 

Figure D-23. RF measurements of GN-11 (τon = 1000 ns, ζ = 0.2500).......................................82 

Figure D-24. IF measurements of GN-11 at INRTOV ....................................................................83 

Figure D-25. RF measurements of GN-12 (τon = 1000 ns, ζ = 0.1250).......................................84 

Figure D-26. IF measurements of GN-12 at INRTOV ....................................................................85 

Figure D-27. RF measurements of GN-13 (τon = 1000 ns, ζ = 0.0625).......................................86 

Figure D-28. IF measurements of GN-13 at INRTOV ....................................................................87 

Figure D-29. RF measurements of GN-14 (τon = 10,000 ns, ζ = 0.5000)....................................88 

Figure D-30. IF measurements of GN-14 at INRTOV ....................................................................89 

Figure D-31. RF measurements of GN-15 (τon = 10,000 ns, ζ = 0.2500)....................................90 

Figure D-32. IF measurements of GN-15 at INRTOV ....................................................................91 

Figure D-33. RF measurements of GN-16 (τon = 10,000 ns, ζ = 0.1250)....................................92 

Figure D-34. IF measurements of GN-16 at INRTOV ....................................................................93 

Figure D-35. RF measurements of GN-17 (τon = 10,000 ns, ζ = 0.0625)....................................94 

Figure D-36. IF measurements of GN-17 at INRTOV ....................................................................95 

Figure D-37. RF measurements of GN(MB)-01 (b = 1, d = 1) ...................................................96 

Figure D-38. IF measurements of GN(MB)-01 at INRTOV ...........................................................97 

Figure D-39. RF measurements of GN(MB)-02 (b = 3, d = 1) ...................................................98 

Figure D-40. IF measurements of GN(MB)-02 at INRTOV ...........................................................99 

Figure D-41. RF measurements of GN(MB)-03 (b = 3, d = 2) .................................................100 

Figure D-42. IF measurements of GN(MB)-03 at INRTOV .........................................................101 

Figure D-43. RF measurements of GN(MB)-04 (b = 7, d = 1) .................................................102 
xi

Figure D-44. IF measurements of GN(MB)-04 at INRTOV .........................................................103 

Figure D-45. RF measurements of GN(MB)-05 (b = 7, d = 2) .................................................104 

Figure D-46. IF measurements of GN(MB)-05 at INRTOV .........................................................105 

Figure D-47. RF measurements of GN(MB)-06 (b = 7, d = 6) .................................................106 

Figure D-48. IF measurements of GN(MB)-06 at INRTOV .........................................................107 

Figure D-49. RF measurements of GN(MB)-07 (b = 13, d = 1) ...............................................108 

Figure D-50. IF measurements of GN(MB)-07 at INRTOV .........................................................109 

Figure D-51. RF measurements of GN(MB)-08 (b = 13, d = 2) ...............................................110 

Figure D-52. IF measurements of GN(MB)-08 at INRTOV .........................................................111 

Figure D-53. RF measurements of GN(MB)-09 (b = 13, d = 12) .............................................112 

Figure D-54. IF measurements of GN(MB)-09 at INRTOV .........................................................113 
xii

TABLES 

Page 

Table 1. GN Gating Parameters .............................................................................................4 

Table 2. Measured DTV Susceptibility and FEC Performance for GN Interference ..........11 

Table 3. Temporal Characteristics of GN Signals Band-Limited to BDTV ............................17 

Table 4. Amplitude Characteristics of GN Signals Band-Limited to BDTV...........................21 

Table A-1. GN(MB) Gating Parameters ..................................................................................31 

Table A-2. Measured DTV Susceptibility and FEC Performance for GN(MB) 

Interference ............................................................................................................32 

Table A-3. Temporal Characteristics of GN(MB) Signals Band-Limited to BDTV ...................39 

Table A-4. Amplitude Characteristics of GN(MB) Signals Band-Limited to BDTV..................39 

Table B-1. Operational Scenario for DTV Interference Susceptibility Tests..........................43 

Table B-2. Probability of Pre-Viterbi Bit Error and Post-RS Segment Error Near TOV........49 

Table B-3. Signal Powers at the TOV for Gaussian Noise Interference..................................51 

Table D-1. RF VSA Measurement Settings.............................................................................58 

Table D-2. RF P/A (dB) of GN and GN(MB) Signals Band-Limited to Different 

Bandwidths ............................................................................................................60 

Table D-3. IF P/A (dB) of GN and GN(MB) Signals at INRTOV and Band-Limited to BDTV .....61 
INTERFERENCE POTENTIAL OF ULTRAWIDEBAND SIGNALS 

PART 2: MEASUREMENTS OF GATED-NOISE INTERFERENCE TO C-BAND 

SATELLITE DIGITAL TELEVISION RECEIVERS 

Michael Cotton,1 Robert Achatz,1 Jeffery Wepman,1 and Paul Runkle2

This report demonstrates that digital television (DTV) susceptibility to gatednoise interference cannot be predicted by interference power characteristics alone. 

It was found that DTV susceptibility is also dependent on temporal characteristics 

of the interfering signal and the bandwidth of the DTV receiver. A test system 

was developed to inject interference with known characteristics into a victim 

receiver and quantitatively measure susceptibility. In this experiment, a C-band 

satellite DTV victim receiver was exposed to gated-noise interference, whose 

temporal characteristics are defined by gating parameters such as on-time, 

fractional on-time, and off-time. The specific gating parameters considered in this 

report include on-times of 0.01, 0.10, 1.00, and 10.00 μs and fractional on-times 

of 1.00, 0.50, 0.25, 0.125, and 0.0625. Results showed that DTV susceptibility 

was strictly dependent on average power of the interfering signal only when offtimes were less than the reciprocal bandwidth of the victim receiver. For longer 

off-times, however, susceptibility was dependent on the temporal characteristics 

of the interfering signal. Moreover, high correlation was observed between 

susceptibility and forward error correction performance of the receiver. 

Key words: digital television; interference; satellite communications; ultrawideband 

1. INTRODUCTION 

In April 2002, the Federal Communications Commission (FCC) released FCC 02-48 [1] 

legalizing intentional, low-power ultrawideband (UWB) emissions between 3.1 GHz and 10.6 

GHz for communications devices operated indoors. UWB emissions were limited to -41 dBm 

average power in 1-MHz bandwidth and 0 dBm peak power in 50-MHz bandwidth, where 

average power is measured over a 1-millisecond integration time and peak power measurement 

duration is unspecified. The rules define a UWB device as one that emits signals with 10-dB 

bandwidth greater than 500 MHz or greater than 20% of the center frequency. 

The FCC rules do not specify how the bandwidth requirement is achieved, consequently 

allowing industry considerable breadth in choosing a modulation. This breadth is exemplified by 

the development of Direct-Sequence Ultrawideband (DS-UWB) and Multi-band Orthogonal 

Frequency-Domain Multiplexing (MB-OFDM) ultrawideband technologies. Proponents of DSUWB and MB-OFDM both seek standardization from IEEE (Institute of Electrical and 

Electronics Engineers) 802.15 working group 3a on high-rate (greater than 20 million bits per 

 

1

 The authors are with the Institute for Telecommunication Sciences, National Telecommunications and Information 

Administration, U.S. Department of Commerce, Boulder, Colorado 80305. 

2

 The author is with Signal Innovations Group, Inc., Durham, North Carolina 27713. 
2 

second) Wireless Personal Area Networks (WPAN). As the name implies, WPAN is intended for 

short-distance (nominally less than 10 meters) wireless networking of devices such as PCs, 

personal digital assistants, and mobile phones. 

Both DS-UWB and MB-OFDM transmitters are based on state-of-the-art integrated circuitry. 

DS-UWB modulation controls pulse polarity and hence supports phase shifting modulations. It 

achieves its ultra-wide bandwidth by transmitting sufficiently narrow pulses. MB-OFDM 

simultaneously modulates 122 carriers spaced 4.125 MHz apart to achieve its ultra-wide 

bandwidth and frequency hops the modulated carriers between non-overlapping bands. 

Since previous work performed at the Institute for Telecommunication Sciences (ITS) [2 – 5] did 

not specifically look at susceptibility of receivers to interference from DS-UWB or MB-OFDM 

signals, and since there is little published information on this subject, ITS entered into a 

Cooperative Research and Development Agreement (CRADA) with the Freescale subsidiary of 

Motorola, Inc. to study how susceptibility could be quantified in terms of interference signal 

characteristics. 

1.1. Experiment 

Interference potential is a general concept where performance degradation of a victim receiver is 

predicted from interference signal characteristics. Interference potential is derived from 

numerous susceptibility tests on receivers with a variety of bandwidths and signal demodulation 

techniques. This report describes one such test where C-band satellite digital television (DTV) is 

exposed to gated-noise interference. Development of the test system and procedure was 

described in Part 1 of this report series [6]. 

In this report, only continuous- and gated-noise signals are considered as interferers. While it is 

unlikely that these signals will be used in communications, their similarities to DS-UWB and 

MB-OFDM, respectively, are unmistakable and their analytic tractability is profoundly useful. 

More specifically, these signals emulate the noisy nature of DS-UWB and MB-OFDM as well as 

the gating characteristics of MB-OFDM caused by frequency hopping in and out of a victim 

receiver operational band. This emulation is accomplished without the mathematical 

complexities associated with actual UWB modulations. Comparisons between continuous noise 

and DS-UWB, and gated noise and MB-OFDM, will be discussed in Part 3 of this report series. 

C-band satellite television was chosen as the victim receiver for the susceptibility tests because it 

demodulates signals transmitted in the 3.7 to 4.2 GHz frequency range, which lies within the 

band allocated for UWB operation. It also uses a variety of bandwidths and signal demodulation 

techniques, which makes it an ideal victim receiver for the study of interference potential. 

Additionally, instruments capable of providing quantitative signal quality data from various 

receiver subsystems are readily available. 
3 

1.2. Organization of Report 

The main body of this report presents DTV susceptibility data and characterization 

measurements for gated-noise interference with the following gating parameters: on-time 

(τon) = {10, 100, 1000, 10000} ns and fractional on time (ζ) = {1.0, 0.5, 0.25, 0.125, 0.0625}. 

These signals are denoted by the acronym GN. 

Section 2 provides DTV susceptibility test results plotted two different ways. First, post-ReedSolomon segment error rate (SER) and pre-Viterbi bit error rate (BER) are plotted as a function 

of interference-to-noise ratio (INR) to demonstrate how susceptibility depends on average power 

of the interfering signals. Second, INR and BER at the threshold of visibility (TOV), i.e., INRTOV

and BERTOV, are plotted as a function of ζ to demonstrate how DTV susceptibility and forward 

error correction (FEC) performance depend on the gating parameters of the interfering signals. 

Section 3 provides temporal and amplitude analyses of measured GN signals to demonstrate the 

effects of band-limiting. The temporal analysis is based on crossing statistics. Burst duration 

(BD) and burst interval (BI) estimates of band-limited GN signals are compared to on- and offtimes of the corresponding gating functions. The amplitude analysis is based on amplitude 

probability distributions (APDs). Peak-to-average ratio (P/A) estimates of the band-limited GN 

signals are compared to corresponding ultra-wide-bandwidth P/A limits. Also provided in 

Section 3 is a spectral analysis based on power spectral densities (PSDs) of measured GN 

signals. 

 

Section 4 discusses how DTV susceptibility depends on the characteristics of interfering signals. 

It summarizes the important points of the test, describes findings, and evaluates the significance 

and scope of the findings. 

Appendices to this report contain information supporting the main body. Appendix A provides 

DTV susceptibility test results and signal characterization measurements for gated-noise signals 

that emulate MB-OFDM. Appendix B gives an overview of the test system, provides precise 

measurement definitions for signal-to-noise ratio (SNR), INR, SER, and BER, and provides some 

degree of validation via comparison of theoretical and measured DTV signal quality metrics for 

Gaussian noise degradation. Appendix C develops theoretical expressions for the amplitude and 

spectral properties of gated Gaussian noise in an ultra-wide transmission bandwidth. Finally, 

Appendix D provides APDs of the gated-noise signals in a variety of bandwidths measured at the 

satellite radio frequency (RF) as well as APDs of the signals at the first intermediate frequency 

(IF) in the presence of low-noise block downconverter (LNB) noise for interference powers 

corresponding to INRTOV. 
4 

2. DTV SUSCEPTIBILITY TO GN INTERFERENCE 

Results of the DTV susceptibility tests for GN interference are described in this section. It 

presents gating parameters, discusses relevant signal powers and DTV signal quality metrics, and 

provides SER and BER versus INR plots and INRTOV and BERTOV versus ζ plots. 

2.1. Gating Parameters 

Table 1 gives on-time, fractional on-time, and off-time (τoff) gating parameters of the periodically 

gated-noise interference signals considered in the main body of this report. The set of gatednoise signals in Table 1 is denoted by the acronym GN, and each individual signal is specified by 

identifiers in the first column. An illustration of the gating parameters is given in Figure 1. 

Appendix A extends the scope of this experiment to GN(MB) interference signals, which are 

gated-noise signals that emulate MB-OFDM. 

 Table 1. GN Gating Parameters 

 Figure 1. Simulated gated-noise signal, GN-10. 

2.2. Signal Powers and DTV Signal Quality Metrics 

Figure 2 illustrates reference points for the signal powers and DTV signal quality metrics 

acquired during the DTV susceptibility tests. SNR and INR define the average power of the DTV 

and interfering signals. These average power ratios were derived from vector signal analyzer data 

measured at IF and band-limited to BDTV = 19.51 MHz in post-measurement processing by the 

same root-raised-cosine (RRC) filter found in the demodulator of the victim receiver. Figure B-1 

GN τon (μs) τoff (μs) ζ

01 ∞ 0.00 1.0000 

02 0.01 0.01 0.5000 

03 0.01 0.03 0.2500 

04 0.01 0.07 0.1250 

05 0.01 0.15 0.0625 

06 0.10 0.10 0.5000 

07 0.10 0.30 0.2500 

08 0.10 0.70 0.1250 

09 0.10 1.50 0.0625 

10 1.00 1.00 0.5000 

11 1.00 3.00 0.2500 

12 1.00 7.00 0.1250 

13 1.00 15.00 0.0625 

14 10.00 10.00 0.5000 

15 10.00 30.00 0.2500 

16 10.00 70.00 0.1250 

17 10.00 150.00 0.0625 
5 

provides a block diagram of the test hardware configuration and Section B.2 mathematically 

describes the power ratio measurements. DTV signal quality metrics SER and BER were 

acquired with the MPEG-2 transport stream monitor.3

 Section B.3 provides mathematical 

definitions of the DTV signal quality metrics. 

Figure 2. SNR, SNR′, INR, INR′, BER, and SER reference points. 

It is important to note that SNR and INR were not measured at the same point as BER. 

Theoretical expressions for DTV signal quality metrics for Gaussian noise degradation are 

provided in Section B.4; these expressions use signal-to-noise ratio at the output of the 

demodulator (SNR′ ) as the dependent variable. Equation (B-1) was derived empirically to 

account for imperfect demodulation effects and compute SNR′ from SNR. Using this model, 

SNR′ = {8.2, 10.5, 12.5} dB was calculated from SNR = {9, 12, 15} dB. Note that this model was 

derived under Gaussian noise assumptions and cannot be generalized for gated-noise interference 

to obtain INR′ from INR without further research. Therefore, test results are displayed as a 

function of the measurable dependent variables SNR and INR. 

2.3. DTV Signal Quality as a Function of Interference Average Power 

Figures 3 – 8 provide composite plots of measured SER and BER as a function of INR for 

SNR = {9, 12, 15} dB. Each page is dedicated to a single SNR, each plot is dedicated to a specific 

τon, and each curve represents a single ζ. Figures 3, 5, and 7 provide composite plots of SER

while Figures 4, 6, and 8 provide composite plots of BER. The following are general comments 

regarding the shift, separation, and slope of these curves. 

Both SER and BER shifted toward greater INR with increasing SNR. This occurred because more 

interference was needed to degrade stronger satellite signals. 

 

3

 Modulation error ratio (MER) was also acquired with the MPEG-2 stream monitor. MER is an important DTV 

signal quality metric referenced to the output of the demodulator. Measured MER, however, was inconsistent with 

theory which prevented its use in this report. 
6 

SER curves with fixed SNR and τon show increased separation (from the continuous-noise case) 

with decreasing ζ. Likewise, all curves with fixed SNR and ζ exhibit increased separation with 

increasing τon. Hence, SER curves with τon = 10 ns and ζ ≥ 0.25 lay close to the continuous-noise 

case, while those with τon = 10,000 ns and ζ = 0.0625 had the greatest separation. A notable 

anomaly to this trend occurred for GN-09 (τon = 100 ns, ζ = 0.0625), where the shallow slope of 

the SER curve caused it to cross higher-ζ SER curves. 

SER curves were generally steeper than corresponding BER curves, which indicates that SER was 

more sensitive than BER to changes in average interference power. SER steepness was due to 

two stages of forward error correction (FEC), which were applied to post-Reed-Solomon 

segments but not to pre-Viterbi bits. Another trend was observed for sufficiently small ζ, i.e., 

ζ = 0.0625, where slopes of the SER curves were flatter compared to higher-ζ cases. This may be 

attributed to conditions more favorable to FEC performance or to longer off-times where errors 

were unlikely. In either case, DTV susceptibility to small-ζ gated-noise interference seemed to be 

more dependent on the temporal characteristics than on the power characteristics of the 

interference signal. 
7 

Figure 3. SER versus INR for a DTV receiver operating at SNR = 9 dB and exposed to 

GN interference. 

Figure 4. BER versus INR for a DTV receiver operating at SNR = 9 dB and exposed to 

GN interference. 
8 

Figure 5. SER versus INR for a DTV receiver operating at SNR = 12 dB and exposed to 

GN interference. 

Figure 6. BER versus INR for a DTV receiver operating at SNR = 12 dB and exposed to 

GN interference. 
9 

Figure 7. SER versus INR for a DTV receiver operating at SNR = 15 dB and exposed to 

GN interference. 

Figure 8. BER versus INR for a DTV receiver operating at SNR = 15 dB and exposed to 

GN interference. 
10 

2.4. DTV Susceptibility and FEC Performance as a Function of Interference 

Fractional On-Time 

Figure 9 displays measured SER and BER curves for a DTV victim receiver operating at 

SNR = 15 dB and exposed to increasing levels of continuous-noise interference. This figure also 

identifies important DTV susceptibility and FEC performance metrics. Importantly, 

SERTOV = 10-4 is a level identified by video quality studies [7] as the threshold of visibility where 

video quality degradation is first evident. 

INR that corresponds to SERTOV, INRTOV, is our primary DTV susceptibility metric. That is, 

receiver susceptibility increases as INRTOV decreases. In Figure 9, INRTOV is found vertically from 

the intersection of the measured SER curve and the SERTOV horizontal line. 

BER that corresponds to SERTOV, BERTOV, is our FEC performance metric. This metric quantifies 

the ability of the FEC to overcome bit errors caused by interference to achieve SERTOV. In other 

words, larger BERTOV indicates more corrected bits and better FEC performance. In Figure 9, 

BERTOV is found horizontally from the intersection of INRTOV and the measured BER curve. 

Figure 9. Illustration of threshold-of-visibility metrics. 

Table 2 gives INRTOV and BERTOV metrics for all GN interference tests. A distinctive trend was the 

positive correlation between INRTOV and BERTOV. This demonstrates that DTV susceptibility was 

dependent on how effective the FEC was at overcoming bit errors caused by the interference. For 

example, the FEC was most effective at mitigating continuous-noise degradation and the receiver 

was least susceptible to continuous-noise interference. 
11 

Table 2. Measured DTV Susceptibility and FEC Performance for GN Interference 

Gating Parameters SNR = 9 dB SNR = 12 dB SNR = 15 dB

GN 

τon (μs) τoff (μs) ζ INRTOV

(dB) BERTOV

INRTOV

(dB) BERTOV

INRTOV

(dB) BERTOV

01 ∞ 0.00 1.0000 0.7 0.038 5.4 0.038 9.2 0.038 

02 0.01 0.01 0.5000 0.9 0.038 5.5 0.038 9.0 0.038 

03 0.01 0.03 0.2500 0.7 0.038 5.6 0.038 9.0 0.038 

04 0.01 0.07 0.1250 0.1 0.036 5.1 0.034 8.5 0.034 

05 0.01 0.15 0.0625 -0.3 0.031 4.1 0.029 7.5 0.029 

06 0.10 0.10 0.5000 0.4 0.035 5.0 0.033 8.4 0.033 

07 0.10 0.30 0.2500 -0.3 0.030 3.8 0.028 7.5 0.028 

08 0.10 0.70 0.1250 -1.2 0.025 3.2 0.023 6.7 0.023 

09 0.10 1.50 0.0625 -1.5 0.021 3.4 0.018 7.0 0.018 

10 1.00 1.00 0.5000 -0.3 0.032 4.2 0.030 7.5 0.030 

11 1.00 3.00 0.2500 -2.2 0.022 1.8 0.018 5.1 0.018 

12 1.00 7.00 0.1250 -4.6 0.015 -0.4 0.011 2.7 0.011 

13 1.00 15.00 0.0625 -6.2 0.012 -2.5 0.007 1.1 0.007 

14 10.00 10.00 0.5000 -1.6 0.025 2.8 0.022 6.3 0.022 

15 10.00 30.00 0.2500 -4.1 0.017 0.2 0.012 3.7 0.012 

16 10.00 70.00 0.1250 -6.5 0.013 -2.2 0.007 1.1 0.007 

17 10.00 150.00 0.0625 -8.6 0.010 -4.5 0.004 -1.2 0.004 

Figures 10 – 15 plot INRTOV and BERTOV as a function of 1/ζ in dB, where 

ζ = {1.00, 0.50, 0.25, 0.125, 0.0625} correspond to 10log(1/ ζ) = {0.00, 3.01, 6.02, 9.03, 12.04} 

dB. The horizontal dashed reference line in each INRTOV plot corresponds to DTV susceptibility 

that is strictly dependent on average power of the interference signal. As an example, Figure 16 

illustrates three gated-noise signals with different ζ but the same average power. If susceptibility 

were strictly dependent on average power, then the victim receiver would be equally susceptible 

to each of these signals. 

For fixed SNR and τon, INRTOV decreased (relative to the continuous-noise case) with decreasing ζ. 

Likewise, for fixed SNR and ζ, INRTOV decreased with increasing τon. Hence, 

INRTOV(τon = 10 ns, ζ ≥ 0.25) lay close to the horizontal reference line, while 

INRTOV(τon = 10,000 ns, ζ = 0.0625) deviated the furthest. A notable anomaly to this trend 

occurred when INRTOV(τon = 100 ns, ζ = 0.0625) was greater than INRTOV(τon = 100 ns, ζ = 0.125). 

These observations demonstrate that DTV susceptibility was dependent on temporal parameters 

of the interfering signal, i.e., τon and τoff. If τoff was less than or comparable to the reciprocal 

bandwidth of the victim receiver RRC filter, i.e., approximately 1/BDTV = 51.3 ns, then INRTOV

clustered near the horizontal reference line and DTV susceptibility was strictly dependent on 

average power of the interference signal (independent of τon and ζ). However, if τoff was 

significantly greater than the reciprocal bandwidth of the victim receiver, then DTV 

susceptibility was clearly dependent on τon and ζ. 
12 

Figure 10. INRTOV versus 10log(1/ζ) for a DTV receiver operating at SNR = 9 dB and 

exposed to GN interference. 

Figure 11. BERTOV versus 10log(1/ζ) for a DTV receiver operating at SNR = 9 dB and 

exposed to GN interference. 
13 

Figure 12. INRTOV versus 10log(1/ζ) for a DTV receiver operating at SNR = 12 dB and 

exposed to GN interference. 

Figure 13. BERTOV versus 10log(1/ζ) for a DTV receiver operating at SNR = 12 dB and 

exposed to GN interference. 
14 

Figure 14. INRTOV versus 10log(1/ζ) for a DTV receiver operating at SNR = 15 dB and 

exposed to GN interference. 

Figure 15. BERTOV versus 10log(1/ζ) for a DTV receiver operating at SNR = 15 dB and 

exposed to GN interference. 
15 

Figure 16. Simulated gated-noise signals with the same average power. 
16 

3. CHARACTERIZATION OF GN SIGNALS

Signal characterization of the complex-baseband (CBB) gated-noise signals was accomplished 

via temporal, amplitude, and spectral analyses. Appendix C provides a theoretical evaluation of 

the corresponding amplitude and spectral characteristics of gated-noise signals in an ultra-wide 

transmission bandwidth. To evaluate the effects of band-limiting, the GN signals were measured 

with the vector signal analyzer (VSA) under optimal measurement conditions at the RF output of 

the vector signal generator (VSG) and under TOV operational conditions at the IF. Appendix D 

provides a description of the measurement setup, RF measurement results in various bandwidths, 

i.e., 36, 10, 1, and 0.1 MHz, and IF measurement results at the three different SNRs. Unless 

otherwise noted, analyses in this section use RF measurements sampled at fs = 46.08 MSps 

(corresponding to VSA span = 36 MHz) and band-limited to BDTV with the victim receiver RRC 

filter applied in post-measurement processing. 

3.1. Temporal Analysis 

Temporal characteristics of GN signals were evaluated with crossing statistics, which provide 

probabilities of the time a signal crosses an amplitude threshold and stays either above or below 

that threshold. Historically, this type of analysis has been used to study pulse statistics of noise 

[8], hence the terms pulse duration and pulse interval depicted in Figure 17. In this analysis of 

gated noise, their utility has been extended to the temporal statistics of noise bursts; accordingly, 

the terminology was changed to burst duration (BD) and burst interval (BI) as illustrated in 

Figure 18. For our purposes, the 10th percentile of the cumulative distribution function (CDF) of 

BD and BI using a threshold equal to -70 dBm was optimal for quantifying the effects of bandlimiting on temporal characteristics of the GN signals. 

 Figure 17. Illustration of pulse duration and pulse interval. 

Table 3 summarizes the effects of band-limiting the GN signals to BDTV. Note that BD and BI are 

given only when gating was resolved and the CDFs provided meaningful estimates of the bandlimited on- and off-times, respectively. The band-limited fractional on-time, ζDTV, was computed 

as BD/(BD + BI). As expected, band-limiting lengthened on-times, shortened off-times, and 

increased fractional on-times. Band-limited metrics approached the gating parameters only when 

τon and τoff were significantly larger than 1/BDTV. 
17 

Figure 18. Illustration of burst duration and burst interval. 

Table 3. Temporal Characteristics of GN Signals Band-Limited to BDTV

Gating Parameters Band-Limited Metrics GN 

τon (μs) τoff (μs) ζ BD(μs) BI(μs) ζDTV

01 ∞ 0.00 1.0000 1.00 

02 0.01 0.01 0.5000 1.00 

03 0.01 0.03 0.2500 1.00 

04 0.01 0.07 0.1250 

05 0.01 0.15 0.0625 

06 0.10 0.10 0.5000 

07 0.10 0.30 0.2500 0.2 0.2 0.50 

08 0.10 0.70 0.1250 0.2 0.6 0.25 

09 0.10 1.50 0.0625 0.2 1.4 0.13 

10 1.00 1.00 0.5000 1.1 0.9 0.55 

11 1.00 3.00 0.2500 1.1 2.9 0.28 

12 1.00 7.00 0.1250 1.1 6.9 0.14 

13 1.00 15.00 0.0625 1.1 14.9 0.07 

14 10.00 10.00 0.5000 10.1 9.9 0.51 

15 10.00 30.00 0.2500 10.1 29.9 0.253 

16 10.00 70.00 0.1250 10.1 69.9 0.126 

17 10.00 150.00 0.0625 10.1 149.9 0.063 
18 

3.2. Amplitude Analysis 

Random amplitudes of the gated-noise signals were characterized with the amplitude probability 

distribution, which describes the probability that signal amplitude exceeds a certain value. In this 

report, APDs are plotted on Rayleigh graphs where Rayleigh-distributed amplitudes of complexGaussian noise appear as a negatively-sloped, straight line. The sorting method, documented in 

Appendix D of Part 1, was used to estimate and plot APDs of 217 = 131,072 samples that are free 

of correlation introduced by the measurement system and post-measurement band-limiting. 

Figures 19 – 22 provide composite APD plots of the measured GN signals. Each plot represents a 

specific τon, and each curve within a plot represents a different ζ. Dashed lines represent the APD

of the continuous-noise signal, GN-01. The upper bound of the shaded region is the average 

power of the VSA noise, approximately -79.7 dBm in BDTV. 

Band-limiting had profound effects on the APDs of the GN signals. If τoff exceeded 1/BDTV a steplike APD occurred, where higher amplitudes primarily corresponded to elongated on-times and 

lower amplitudes to the shortened off-times. This was most pronounced for GN-17 

(τon = 10,000 ns, ζ = 0.0625). If τoff was less than or comparable to 1/BDTV a negatively-sloped, 

straight APD occurred, corresponding to Rayleigh-distributed amplitudes due to elongated noise 

bursts overlapping each other. This was most pronounced for GN-02 (τon = 10 ns, ζ = 0.50). 

Peak-to-average ratio is a metric derived from the APD as illustrated in Figure 23 for GN-10. 

When interpreting P/A results, it is important to understand the bandwidth that peak and average 

powers were measured in, the duration or number of samples, and the statistical definition of 

peak in terms of percentage of samples. In this study, peak and average powers were measured in 

the same bandwidth to compute a single P/A. Also, peak power is defined as the amplitude 

exceeded 0.01% of the time, which corresponds to 13 of 131,072 samples. Figure C-2 shows 

how P/A changes with various peak definitions. 

Table 4 summarizes measured P/A and APD characteristics for the band-limited GN signals. 

Also included are ultra-wide bandwidth limits to P/A derived in Section C.1. APD characteristics 

are labeled RAYL for Rayleigh-distributed amplitudes or RG for resolved gating, i.e., step-like 

APD whose amplitude falls below VSA average noise power at least 10% of the time. 

Band-limiting affected P/A. If τoff far exceeded 1/BDTV, then P/A approached the ultra-wide 

transmission bandwidth limit. If τoff was less than 1/BDTV, then P/A approached the 9.6-dB value 

for Rayleigh-distributed amplitudes. When τoff was between these extremes, P/A transitioned 

between the limits. 
19 

Figure 19. APDs of GN signals with τon = 10 ns band-limited to BDTV. 

Figure 20. APDs of GN signals with τon = 100 ns band-limited to BDTV.
20 

Figure 21. APDs of GN signals with τon = 1,000 ns band-limited to BDTV. 

Figure 22. APDs of GN signals with τon = 10,000 ns band-limited to BDTV. 
21 

Table 4. Amplitude Characteristics of GN Signals Band-Limited to BDTV

Ultra-wide Bandwidth Limits Band-Limited Metrics GN P/A (dB) APD P/A (dB) APD 

01 9.6 RAYL 9.6 RAYL 

02 12.3 RG 9.9 RAYL 

03 14.9 RG 9.7 RAYL 

04 17.5 RG 11.5 

05 20.1 RG 14.2 

06 12.3 RG 12.2 

07 14.9 RG 14.6 RG 

08 17.5 RG 17.3 RG 

09 20.1 RG 19.6 RG 

10 12.3 RG 12.4 RG 

11 14.9 RG 15.0 RG 

12 17.5 RG 17.6 RG 

13 20.1 RG 20.3 RG 

14 12.3 RG 12.3 RG 

15 14.9 RG 15.1 RG 

16 17.5 RG 17.8 RG 

17 20.1 RG 20.1 RG 

 Figure 23. Illustration of P/A for GN-10 band-limited to BDTV. 
22 

3.3. Spectral Analysis 

Spectral characteristics of the gated-noise signals were characterized with the power spectral 

density, which represents the average power present per unit bandwidth as a function of 

frequency. Section C.2 provides a theoretical analysis of the PSD for gated Gaussian noise. In 

short, it can be considered to be constant over the bandwidth of interest. 

Figures 24 – 27 provide PSDs of the GN signals over the entire VSA bandwidth, i.e., the victim 

receiver RRC filter was not applied to the data in post-measurement processing. PSDs were 

calculated by averaging squared spectrum magnitudes of rectangular-windowed, nonoverlapping blocks of signal data. The periodic nature of the GN signals required that the block 

size be an integer multiple of the gating period. To have the same ∆f for all PSDs, the block size 

must also be a common integer multiple of all gating periods. For the GN signals, these 

requirements were satisfied with a block size of 160 μs, which corresponds to ∆f = 6.2 kHz. This 

allowed 500 blocks to be averaged, given the 4 million samples available in the acquired data 

sets. 

The figures show that the power density of the gated signals decreased in proportion to ζ. In 

addition, the spectral spike at 0 Hz was due to VSG local-oscillator feed-through. The influence 

of the VSG local-oscillator feed-through to test results was discussed in Appendix C of Part 1.
23 

Figure 24. PSDs of GN signals with τon = 10 ns. 

Figure 25. PSDs of GN signals with τon = 100 ns. 
24 

Figure 26. PSDs of GN signals with τon = 1,000 ns. 

Figure 27. PSDs of GN signals with τon = 10,000 ns. 
25 

4. CONCLUSION 

The objective of this experiment was to measure and evaluate the susceptibility of a C-band 

satellite DTV receiver to gated-noise interference. Results in this report have been measured with 

a reliable test system and repeatable procedures. Validation against theory is demonstrated in 

Appendix B. Results are expected to be fundamental in understanding interference caused by 

DS-UWB and MB-OFDM signals. In these concluding remarks, findings are summarized and 

their significance explained. 

Temporal analyses showed that band-limiting the GN interference signals elongated on-times 

and shortened off-times, which had profound effects on corresponding APDs. When τoff was less 

than or comparable to the receiver reciprocal bandwidth, the elongated on-times overlapped, 

producing Rayleigh amplitude statistics. When τoff was several times greater than the reciprocal 

bandwidth, the elongated on-times remained distinct, producing gated-noise amplitude statistics. 

These temporal and amplitude observations help explain the susceptibility results. When τoff was 

less than or comparable to the reciprocal bandwidth, DTV susceptibility results were strictly 

dependent on average power of the band-limited interference. This is because Rayleighdistributed amplitudes correspond to zero-mean Gaussian noise, which is completely 

characterized by its variance or average power. Moreover, the DTV receiver was least 

susceptible to signals that resembled continuous noise after band-limiting. Conversely, when τoff

was several times greater than the reciprocal bandwidth, gating was resolved and susceptibility 

results were clearly dependent on the gating parameters τon and ζ. The DTV receiver was more 

susceptible to the gated-noise signals that maintained some semblance of a gated signal after 

band-limiting. More specifically, DTV susceptibility increased with increasing τon and 

decreasing ζ. 

Interestingly, peak-to-average ratios of the band-limited GN signals were also dependent on τon

and ζ. In fact, as demonstrated in Figures 28 – 30, there was some correlation between measured 

DTV susceptibility and P/A, i.e., DTV was more susceptible to GN interference with higher P/A. 

However, these figures also show distinct separation between τon curves, which indicates that P/A

alone cannot serve as a sole predictor of DTV interference susceptibility. 

In summary, DTV susceptibility to gated-noise interference cannot be predicted by interference 

power characteristics alone. Indeed, it is essential to consider the temporal parameters of the 

interfering signal as well as the bandwidth of the victim receiver. Additionally, FEC performance 

trends, characterized by BERTOV, behaved similar to DTV susceptibility trends, leading to the 

conclusion that DTV susceptibility is determined largely by FEC performance. 

Caution is advised when extending these results to small ζ. For example, it is entirely likely that 

low susceptibility could be achieved for each τon provided ζ is sufficiently small, which may 

create conditions more favorable to FEC performance or simply provide longer off-times where 

errors are unlikely. Determination of these conditions is beyond the scope of this report. 
26 

Figure 28. INRTOV versus P/A for a DTV receiver operating at SNR = 9 dB and exposed to 

GN interference. 

Figure 29. INRTOV versus P/A for a DTV receiver operating at SNR = 12 dB and exposed to 

GN interference. 
27 

Figure 30. INRTOV versus P/A for a DTV receiver operating at SNR = 15 dB and exposed to 

GN interference. 
28 

5. ACKNOWLEDGMENTS

The authors recognize John McCorkle of Freescale, Inc. for his leadership, insight, and 

insistence on the highest quality. We learned a great deal from working with John in all relevant 

technical areas. 

This investigation required the services of a number of ITS engineers with a broad range of 

expertise, some of whom are not included in the list of authors. The authors recognize Brent 

Bedford for his expertise in test and measurement equipment and techniques; Randy Hoffman, 

Richard Statz, and Steve Engelking for developing much of the low level software routines 

needed to automate the experiment via software control; Stephen Wolf for his expertise in video 

quality assessment; Frank Sanders for sharing knowledge learned in previous interference tests 

on C-band earth station receivers [9]; Dr. Roger Dalke for his knowledge of random processes 

and experimental uncertainty analyses; Andrew Rogers and Michael Mitchell for their attention 

to detail in hardware production and signal characterization measurements; and Dr. William 

Kissick for his support and leadership. 
29 

6. REFERENCES 

[1] “First Report and Order in the matter of ET Docket 98-153 (Revision of Part 15 of the 

Commission’s Rules Regarding Ultra-Wideband Transmission Systems),” FCC 02-48, 

adopted Feb. 14, 2002, released Apr. 22, 2002. 

[2] W.A. Kissick, Ed., “The temporal and spectral characteristics of ultrawideband signals,” 

NTIA Report 01-383, Jan. 2001. 

[3] J.R. Hoffman, M.G. Cotton, R.J. Achatz, R.N. Statz, and R.A. Dalke, “Measurements to 

determine potential interference to GPS receivers from ultrawideband transmission 

systems,” NTIA Report 01-384, Feb. 2001. 

[4] J.R. Hoffman, M.G. Cotton, R.J. Achatz, and R.N. Statz, “Addendum to NTIA Report 01-

384: Measurements to determine potential interference to GPS receivers from 

ultrawideband transmission systems,” NTIA Report 01-389, Sep. 2001. 

[5] J.R. Hoffman, E.J. Haakinson, and Y. Lo, “Measurements to determine potential 

interference to public safety radio receivers from ultrawideband transmission systems,” 

NTIA Report 03-396, Apr. 2003. 

[6] M. Cotton, R. Achatz, J. Wepman, B. Bedford, “Ultrawideband interference potential: Part 

1 – Procedures to characterize ultrawideband emissions and characterize interference 

susceptibility of C-band satellite digital television receivers,” NTIA Report TR-05-419, 

Feb. 2005. 

[7] J.C. Whitaker, “Digital television transmission systems,” Ch. 13 in Standard Handbook of 

Video and Television Engineering, J.C. Whitaker, Ed., New York, NY: McGraw-Hill, 

2000. 

[8] L.R. Espeland and A.D. Spaulding, “Amplitude and time statistics for atmospheric radio 

noise,” ESSA Technical Memorandum, ERLTM-ITS 253, Sep. 1970. 

[9] F. Sanders, “Measurements of pulsed co-channel interference in a 4-GHz digital earth 

station receiver,” NTIA Report 02-393, May 2002. 

[10] ETS 300 421: “Digital broadcasting systems for television, sound, and data services: 

Framing structure, channel coding, and modulation for 11/12 GHz satellite services,” 

European Telecommunications Standards Institute, Dec. 1994. 

[11] ETSI TR 101 290: “Digital Video Broadcasting (DVB); Measurement guidelines for DVB 

systems,” European Telecommunications Standards Institute, v1.2.1, 2001. 
30 
31 

APPENDIX A: EXTENSION OF EXPERIMENT TO GN(MB) SIGNALS 

This appendix provides susceptibility and characterization measurements for gated-noise signals 

that emulate MB-OFDM, i.e., GN(MB) signals. Recall that MB-OFDM is an ultrawideband 

(UWB) signal that hops between 14 bands according to a specified time-frequency code; it is 

specified by the number of bands (b) it hops between and the number of consecutive dwells (d) 

the signal stays in a particular band. To a relatively narrowband victim receiver, MB-OFDM 

appears as gated interference. Table A-1 provides the MB-OFDM parameters, i.e., b and d, and 

corresponding gating parameters, i.e., on-time (τon), off-time (τoff), and fractional on-time (ζ). 

Gating parameters are illustrated in Figure A-1 for GN(MB)-03. 

Table A-1. GN(MB) Gating Parameters 

GN MB-OFDM Parameters Gating Parameters 

(MB) b d τon (μs) τoff (μs) ζ

01 1 1 0.24 0.07 0.7758 

02 3 1 0.24 0.70 0.2586 

03 3 2 0.55 1.32 0.2586 

04 7 1 0.24 1.95 0.1108 

05 7 2 0.55 3.82 0.1108 

06 7 6 1.80 11.32 0.1108 

07 13 1 0.24 3.82 0.0597 

08 13 2 0.55 7.57 0.0597 

09 13 12 3.68 45.07 0.0597 

Figure A-1. Simulated gated-noise signal, GN(MB)-03. 
32 

From the perspective of a victim receiver, MB-OFDM has two gating processes associated with: 

(1) hopping and (2) insertion of zero-prefix and guard-intervals in each MB-OFDM symbol. 

Each MB-OFDM symbol is comprised of a zero-prefix, data block, and guard interval; the MBOFDM symbol period is the sum of its constituents, i.e., TOFDM = TZP + TDATA + TGI , where 

TZP = 60.6 ns, TDATA = 242.4 ns, and TGI = 9.5 ns. Fractional on-time is calculated as 

ζ = TDATA / bTOFDM . τon is approximated by including the zero-prefix and guard interval between 

consecutive dwells and excluding those adjacent to hopping transitions, 

Accordingly, τoff is approximated as 

A.1. DTV Susceptibility to GN(MB) Interference 

Figures A-2 – A-7 provide measured segment error rate (SER) and pre-Viterbi bit error rate 

(BER) versus interference-to-noise ratio (INR). These composite graphs for GN(MB) signals 

correspond to Figures 3 – 8 for GN signals in the main text. 

Figures A-8 – A-13 plot INRTOV and BERTOV versus 1/ζ in dB, where ζ = {0.78, 0.26, 0.11, 0.06} 

correspond to 10log(1/ ζ) = {1.10, 5.87, 9.55, 12.24} dB. These composite graphs for GN(MB) 

signals correspond to Figures 10 – 15 for GN signals. Table A-2 provides INRTOV and BERTOV for 

GN(MB) signals as Table 2 does for GN signals. 

There is no one-to-one correspondence for gating parameters between the two sets. For example, 

τon ≈ {0.24, 0.55, 1.80, 3.68} μs for GN(MB) are different than τon = {0.01, 0.10, 1.00, 10.00} μs 

for GN and 10log(1/ ζ) = {1.10, 5.87, 9.55, 12.24} dB for GN(MB) are different than 

10log(1/ ζ) = {0.00, 3.01, 6.02, 9.03, 12.04} dB for GN. In spite of these discrepancies, GN(MB) 

results lie where expected in the region bounded by 0.10- to 10.00-μs τon curves. 

Table A-2. Measured DTV Susceptibility and FEC Performance for GN(MB) Interference 

Gating Parameters SNR = 9 dB SNR = 12 dB SNR = 15 dB GN 

(MB) τon (μs) τoff (μs) ζ INRTOV

(dB) BERTOV

INRTOV

(dB) BERTOV

INRTOV

(dB) BERTOV

01 0.24 0.07 0.7758 0.5 0.037 5.2 0.036 8.5 0.036 

02 0.24 0.70 0.2586 -0.7 0.030 3.7 0.027 7.0 0.028 

03 0.55 1.32 0.2586 -0.9 0.028 3.5 0.025 6.5 0.025 

04 0.24 1.95 0.1108 -1.9 0.022 2.3 0.018 5.8 0.019 

05 0.55 3.82 0.1108 -3.2 0.018 0.8 0.013 4.2 0.013 

06 1.80 11.32 0.1108 -5.0 0.015 -1.2 0.009 2.3 0.009 

07 0.24 3.82 0.0597 -3.3 0.016 0.7 0.012 4.3 0.011 

08 0.55 7.57 0.0597 -5.1 0.014 -1.1 0.009 2.3 0.008 

09 3.68 45.07 0.0597 -7.4 0.011 -3.3 0.005 -0.3 0.005 

( 1) . off OFDM TZP TGI τ ≈ b − dT + +

. on ≈ dTOFDM − TZP − TGI τ
33 

Figure A-2. SER versus INR for a DTV receiver operating at SNR = 9 dB and exposed to 

GN(MB) interference. 

Figure A-3. BER versus INR for a DTV receiver operating at SNR = 9 dB and exposed to 

GN(MB) interference. 
34 

Figure A-4. SER versus INR for a DTV receiver operating at SNR = 12 dB and exposed to 

GN(MB) interference. 

Figure A-5. BER versus INR for a DTV receiver operating at SNR = 12 dB and exposed to 

GN(MB) interference. 
35 

Figure A-6. SER versus INR for a DTV receiver operating at SNR = 15 dB and exposed to 

GN(MB) interference. 

Figure A-7. BER versus INR for a DTV receiver operating at SNR = 15 dB and exposed to 

GN(MB) interference. 
36 

Figure A-8. INRTOV versus 10log(1/ζ) for a DTV receiver operating at SNR = 9 dB and 

exposed to GN(MB) interference. 

Figure A-9. BERTOV versus 10log(1/ζ) for a DTV receiver operating at SNR = 9 dB and 

exposed to GN(MB) interference. 
37 

Figure A-10. INRTOV versus 10log(1/ζ) for a DTV receiver operating at SNR = 12 dB and 

exposed to GN(MB) interference. 

Figure A-11. BERTOV versus 10log(1/ζ) for a DTV receiver operating at SNR = 12 dB and 

exposed to GN(MB) interference. 
38 

Figure A-12. INRTOV versus 10log(1/ζ) for a DTV receiver operating at SNR = 15 dB and 

exposed to GN(MB) interference. 

Figure A-13. BERTOV versus 10log(1/ζ) for a DTV receiver operating at SNR = 15 dB and 

exposed to GN(MB) interference. 
39 

A.2. Characterization of GN(MB) Signals 

Table A-3 provides band-limited temporal metrics compared to the approximate gating 

parameters of the GN(MB) signals. Table A-3 provides temporal characteristics of GN(MB) 

signals as Table 3 does for GN signals. 

Table A-3. Temporal Characteristics of GN(MB) Signals Band-Limited to BDTV

GN Gating Parameters Band-Limited Metrics 

(MB) τon (μs) τoff (μs) ζ BD(μs) BI(μs) ζDTV

01 0.24 0.07 0.7758 

02 0.24 0.70 0.2586 0.4 0.6 0.40 

03 0.55 1.32 0.2586 0.7 1.2 0.37 

04 0.24 1.95 0.1108 0.4 1.8 0.18 

05 0.55 3.82 0.1108 0.7 3.7 0.16 

06 1.80 11.32 0.1108 1.9 11.2 0.15 

07 0.24 3.82 0.0597 0.4 3.7 0.10 

08 0.55 7.57 0.0597 0.7 7.4 0.09 

09 3.68 45.07 0.0597 3.8 44.9 0.08 

Figures A-14 and A-15 provide amplitude probability distributions (APDs) of single- and multidwell GN(MB) signals, respectively. Table A-4 provides band-limited amplitude metrics 

compared to the corresponding ultra-wide bandwidth limits. Table A-4 provides amplitude 

characteristics of GN(MB) signals as Table 4 does for GN signals. 

Table A-4. Amplitude Characteristics of GN(MB) Signals Band-Limited to BDTV

GN Ultra-wide Bandwidth Limits Band-Limited Metrics 

(MB) P/A (dB) APD P/A (dB) APD 

01 10.6 RG 10.5 

02 14.8 RG 14.7 RG 

03 14.8 RG 14.6 RG 

04 18.0 RG 18.0 RG 

05 18.0 RG 17.9 RG 

06 18.0 RG 17.8 RG 

07 20.3 RG 20.2 RG 

08 20.3 RG 20.1 RG 

09 20.3 RG 19.9 RG 

Figures A-16 – A-17 provide power spectral densities (PSDs) for the GN(MB) signals. PSDs 

were calculated as described in Section 3.3. Block length was chosen as 170.6 μs (∆f = 5.9 kHz), 

which allowed 500 averages. The PSD of GN(MB)-09 (b = 13, d = 12) was excluded because it 

would have forced the number of averages to be less than 500. In Figure A-17, the PSD of 

GN(MB)-05 (b = 7, d = 2) is directly beneath GN(MB)-06 (b = 7, d = 6). 
40 

Figure A-14. APDs of single-dwell GN(MB) signals band-limited to BDTV. 

Figure A-15. APDs of multi-dwell GN(MB) signals band-limited to BDTV. 
41 

Figure A-16. PSDs of single-dwell GN(MB) signals. 

Figure A-17. PSDs of multi-dwell GN(MB) signals. 
42 

APPENDIX B: VERIFICATION OF SUSCEPTIBILITY RESULTS 

Susceptibility of C-band satellite digital television (DTV) to gated-noise interference was 

measured with the test system and procedures described in Part 1 [6]. These tests measured 

effects on DTV signal quality due to increasing levels of interference. DTV signal quality 

metrics collected during the tests include modulation error ratio (MER), pre-Viterbi bit error rate 

(BER), and post-Reed-Solomon segment error rate (SER). 

From the point of view of interference susceptibility tests, it is essential that signal power 

measurements and DTV signal quality metrics be precisely defined. This appendix gives an 

overview of the test system, provides precise measurement definitions for signal-to-noise ratio 

(SNR), interference-to-noise ratio (INR), MER, BER, and SER, and provides some degree of 

validation via comparison of theoretical and measured DTV signal quality metrics for Gaussian 

noise degradation. 

B.1. Test System Overview 

The test system was designed to inject carefully characterized interference into an operating 

satellite DTV receiver and measure susceptibility of the receiver with precisely defined DTV 

signal quality metrics. Figure B-1 is a block diagram of the test system hardware. In this figure 

BPF, LPF, and LNB correspond to bandpass filter, lowpass filter, and low-noise block 

downconverter. 

Figure B-1. Block diagram of DTV interference susceptibility test system. 
43 

The test system: 

• simulated interference signals in software, so the widest range of UWB signal 

parameters were available for testing; 

• generated interference signals with a vector signal generator (VSG), so INR was 

precisely controlled; 

• characterized interference signals with a vector signal analyzer (VSA), which provided 

both amplitude and phase information for post-measurement analyses; 

• simulated the satellite signal, so that scene content and SNR were controlled; 

• conductively coupled signals to the satellite receiver, so uncertainties introduced by 

radio channel interference, attenuation, and distortion were eliminated; 

• evaluated performance degradation objectively and quantitatively with DTV signal 

quality metrics from an MPEG-2 stream monitor; 

• was completely characterized, so that its effects on the test were known; 

• was under software control to eliminate procedural errors. 

For this test, the operational scenario is summarized in Table B-1. Compression, modulation, and 

error correction schemes comply with digital video broadcast (DVB) recommendations described 

in ETS 300 421 [10]. 

 

Table B-1. Operational Scenario for DTV Interference Susceptibility Tests 

Transponder Center Frequency 3820 MHz 

Modulation QPSK with root-raised cosine filter (α = 0.35) 

Compression MPEG-2 

Data Rate 26.970353 Mbps 

Symbol Rate RS = 19.510468 Mbaud 

Segment Rate Rseg = 17,932 segments/second

Reed-Solomon Error Correction RRS = 188/204 

Convolutional Error Correction Rconv = 3/4, K = 7

Interleaving Depth = 12 bytes 

Signal-to-Noise Ratio {8.5, 11.5, 14.5} dB 

B.2. Signal Calibration 

At the beginning of each test, the system was calibrated to ensure that all hardware was operating 

properly and SNR and INR were correct. Figure B-2 provides a simplified model of the four 

calibration measurements: (m1) VSA noise, (m2) combined system noise and VSA noise, (m3) 

combined DTV signal, system noise, and VSA noise, and (m4) combined interference, system 

noise, and VSA noise. For these measurements, DTV signal power was set to a level 

corresponding to the appropriate SNR, the interfering signal power was set to a level that 

produced an accurate VSA measurement, and a 36-MHz VSA span was used. The satellite signal 

path (SSP) and interference signal path (ISP) were characterized in Appendix F of Part 1. 
44 

Figure B-2. Block diagrams for calibration measurements. 

The following equations define these measurements 

where nvsa(t) is the internal noise of the VSA instrument, n0(t) is thermal noise, nsys(t) is the 

system noise, s(t) is the satellite signal, v(t) is the interference signal, and GSSP and GISP are gains 

of SSP and ISP, respectively. The noise analysis was simplified by assuming the gain of the VSA 

to be one; this is justified because gain of the VSA is divided out in the power ratio calculations. 

Measurement results were then band-limited in post-measurement processing by the victim 

receiver RRC filter 

where k is the measurement index, hrrc(t) is the impulse response of the victim receiver RRC 

filter, is the time-average operator, and ∗ is the convolutional operator. Power estimates 

were derived from approximately 2.8 milliseconds of data, i.e., 217 = 131,072 samples. 

( ) ( ) ( ) ( )

( ) ( ) ( ) ( )

( ) ( ) ( )

( ) ( ) ( )

4

3

2

1 0

m t G v t n t n t

m t G s t n t n t

m t n t n t

m t n t n t

ISP sys vsa

SSP sys vsa

sys vsa

vsa

= + +

= + +

= +

= +

2

P m (t) h (t) k k rrc = ∗
45 

Power of the system noise (PN), satellite signal (PS), and interference signal (PI) are calculated as 

where PN is a good estimate because nsys(t) >> n0(t). 

Finally, SNR and INR are computed as 

 

Example calculations are provided in the validation portion of this appendix (see Table B-3). 

B.3. Measured DTV Signal Quality 

The MPEG-2 stream monitor was used to measure DTV signal quality. DTV signal quality 

metrics and their reference points within the receiver include MER and BER at the output of the 

quadrature demodulator, or equivalently at the input of the Viterbi decoder, and SER at the 

output of the Reed-Solomon (RS) decoder. 

During the test, the following procedure was followed at each discrete interference level: 

1. Interference was turned off and the receiver was allowed to acquire and demodulate the 

desired satellite signal in the absence of interference for 20 seconds. 

2. Interference was applied for approximately 200 seconds. 

3. MER, BER, cumulative transport error flag (TEF), and UTC time were sampled during 

the time of interference exposure at about 3 times per second and written to a data file. 

DTV signal quality metrics were acquired with coarse and fine interference-level resolution. For 

coarse resolution, interference level was increased in 2-dB steps, beginning at a level that had 

negligible effect on DTV signal quality and ending where SER was in excess of 0.1. Fineresolution acquisition began 2 dB below the level where the first TEF occurred during coarseresolution acquisition and interference was incremented in 0.1-dB steps until 0.1 SER was again 

achieved. 

.

N

I

N

S

P

P INR

P

P SNR

=

=

, 4 2

3 2

2 1

P P P

P P P

P P P

I

S

N

= −

= −

≈ −
46 

B.3.1. MER

Measured MER is defined as 

where In and Qn are the ideal in- and quadrature-phase samples of the demodulated signal, δI and 

δQ are the error between actual and ideal samples, and N is the number of samples used for 

estimation. The MPEG-2 stream monitor utilized in this experiment derives MER from 512 

samples collected at a rate of approximately 25 Hz. 

B.3.2. BER

Measured pre-Viterbi bit error rate is defined as 

The MPEG-2 stream monitor estimates BER with the circuit illustrated in Figure B-3. This 

circuit compares received bits to the estimated transmit bits. BER measurements use 

226 = 67,108,864 bits which provide good precision to approximately 7·10-5 BER assuming 100 

errors are needed. 

Figure B-3. BER estimation circuit used by MPEG-2 stream monitor. 

Figure B-4 displays simulation results for the BER estimation circuit, where no interference was 

present. Good agreement was found for SNR′ > 4.5 dB corresponding to BER < 0.05, where SNR′

is referenced to the output of the demodulator. Poor agreement at lower SNR′ was due to errors in 

the estimated transmit bits. 

( )

( )

10 log ,

1

2 2

1

2 2

10

⎟

⎟

⎟

⎟

⎠

⎞

⎜

⎜

⎜

⎜

⎝

⎛

+

+

=

∑

∑

=

=

N

n

n n

N

n

n n

I Q

I Q

MER

δ δ

. bit count

bit error count BER =
47 

Figure B-4. Simulation of BER estimation circuit used by MPEG-2 stream monitor. 

B.3.3. SER

Measured SER is defined by 

where TEF(tk) is the cumulative number of segment errors at UTC time tk and Rseg is the number 

of segments per second specified by the DTV operational scenario. Measured SER was computed 

from approximately 200 seconds of data. During this time period, approximately 3.6 million 

segments were transmitted. Each segment is considered to be an independent susceptibility trial. 

Satellite and interference signals were not without systematic uncertainty. More specifically, 

sinusoidal variations of approximately 0.1-dB peak-to-peak with periods of 20 – 50 minutes were 

measured in signal amplitudes with a power meter after the LNB. Subsequent SER fluctuations 

were approximately an order of magnitude, which is explained by the high sensitivity of SER to 

change in signal-to-noise ratio (see Table B-2). This SER fluctuation is only evident during long 

measurement periods when interference is either absent or has negligible effect on SER. For the 

interference tests considered in this report, the 0.1-dB increase in interference power every 220 

seconds increased SER at a rate that rendered the SER systematic fluctuations indistinguishable. 

, ( )

( ) ( )

2 1

2 1

Rseg t t

TEF t TEF t

segment count

segment error count SER −

− = =
48 

B.4. Theoretical DTV Signal Quality for Gaussian Noise Degradation 

This section provides theoretical expressions of MER, BER, and SER for Gaussian noise 

degradation. For a Gaussian noise radio environment, degradation is predictable from the signalto-noise ratio at the output of the demodulator (SNR′ ). 

B.4.1. MER

For Gaussian noise degradation, theoretical MER is equivalent to SNR′ in dB, that is 

B.4.2. BER

Theoretical probability of a bit error for QPSK, comparable to measured BER, is computed as 

where Q represents the Q-function defined as 

B.4.3. SER

Probability of post-Viterbi bit error for QPSK is upper bounded by 

where constraint length K is specified by the operational scenario, dfree is the free distance of the 

code, and w(d) are the code weights. 

Theoretical calculation of SER requires converting Pconv to Pbyte, i.e., the probability of a byte 

error. The conversion factor can be determined mathematically with the assumption of 

independent bit errors [11]; however, if more accuracy is desired the effects of correlated bit 

errors, caused by the Viterbi algorithm, can be simulated. Simulations of Gaussian noise 

degradation near the SNR′ required for PRS = 10-4 have shown a probability of a byte error 

approximately equal to three times the probability of a bit error, i.e., Pbyte ≈ 3Pconv. 

MER = 10 log(SNR′) .

P Q( SNR ) , QPSK = ′

( ) ( ) , 1 ∑

∞

=

≤ ⋅ ′

d d free

conv w d Q d SNR

K

P

. 2 exp 2

1 ( )

2

ξ ξ

π

Q z d

z

∫

∞

⎟

⎟

⎠

⎞

⎜

⎜

⎝

⎛ − =
49 

For the RS scheme specified in Table B-1, a segment error occurs when more than (204 –188)/2 

or 8 byte errors occur in a single segment. Hence, if post-Viterbi byte errors are independent, 

Pbyte is small, and the number of bytes per segment is large, then the upper bound of the 

probability of a post RS segment error can be estimated by 

where M = 8 and λ = 204Pbyte for the RS(204,188) code. 

Figure B-5 shows PQPSK, Pconv, and PRS as a function of SNR′. Table B-2 provides PQPSK and PRS at 

various SNR′ near the threshold of visibility, i.e., PRS = 10-4. Notice that PRS is sensitive to 

changes in SNR′, varying as much as an order of magnitude for each 0.1-dB increment in SNR′. 

In contrast, PQPSK is relatively insensitive. Such differences between PQPSK and PRS are attributed to 

the forward error correction (FEC). 

Figure B-5. Theoretical DTV receiver performance versus SNR′. 

Table B-2. Probability of Pre-Viterbi Bit Error and Post-RS Segment Error Near TOV 

SNR′ (dB) PQPSK PRS

5.0 0.038 0.27 

5.1 0.036 0.046 

5.2 0.034 0.0045 

5.3 0.033 0.00029 

5.4 0.031 0.000014 

, ! ( ) 1

0

λ −λ

=

= > ≤ −∑ e

l

P P m M

M

l

l

RS
50 

B.5. Validation of Measured DTV Quality Metrics for Gaussian Noise Degradation 

In this section, some degree of validation is accomplished by comparing theoretical predictions 

to measured DTV quality metrics for Gaussian noise degradation. Two scenarios are evaluated: 

(1) BER versus SNR in the absence of interference, and (2) BER and SER versus INR for a DTV 

receiver exposed to continuous noise interference. It is important to understand that results in this 

subsection relate to Gaussian noise degradation and cannot be generalized without further 

research. 

B.5.1. BER as a Function of SNR in the Absence of Interference 

The test system was set up as shown in Figure B-1, except the interference signal path was 

terminated. SNR, BER, and SER were measured (as described in Sections B.2 and B.3) at various 

satellite signal powers. Figure B-6 shows measured BER and theoretical PQPSK versus SNR. 

Figure B-6. Theoretical versus measured bit error rate performance of a DTV receiver. 

Presumably, the primary difference between theory and measurement was due to distortions 

introduced by imperfect demodulation that effectively reduced the signal-to-noise ratio. Good 

agreement with measured BER was achieved when an excess noise term, proportional to the 

average power of the satellite signal, was used to model demodulator imperfections. More 

specifically, at the output of the demodulator 

(B-1) , 1 ESR SNR

SNR

P P

P SNR

N

S

+ ⋅ = + ′ =

ε
51 

where Pε is the average power of the excess noise and excess-noise-to-signal ratio was 

determined empirically as dB. ESR = Pε / PS = −16 Using this model, SNR = {9, 12, 15} dB 

measured during the DTV susceptibility test corresponds to SNR′ = {8.2, 10.5, 12.5} dB. 

B.5.2. BER and SER as a Function of INR for Gaussian-Noise Interference 

In this subsection, an “effective signal-to-noise ratio” concept is developed to validate the GN-01 

measurements. This concept is based on the assumption that receiver noise, excess noise, and 

GN-01 interference are all Gaussian noise processes. Theoretical expressions provided in Section 

B.4 are applicable since the addition of these noise processes results in a Gaussian noise process 

with an average power equal to the sum of its constituents. Hence, in the case of GN-01, the 

effective signal-to-noise ratio at the output of the demodulator is expressed as 

Figures B-7 and B-8 provide theoretical versus measured BER and SER, respectively, for a DTV 

receiver operating at the different SNRs and exposed to a range of Gaussian noise interference 

levels. Table B-3 provides theoretical and measured test results for Gaussian noise interference 

that caused degradation at the TOV. Calibration measurements with the VSA provided P1, P2, P3, 

and P4. These measurements were used to compute PS , PI , SNR, and INR. Interestingly, PS / P4 , 

which corresponds to the ratio of signal power to the combined power of interference and system 

noise, was approximately 5.5 dB in all cases. In general, theoretical results using the SNReff ′

model demonstrated good agreement with measured data. 

Table B-3. Signal Powers at the TOV for Gaussian Noise Interference 

Calibration Measurements Susceptibility Test Results Theoretical 

Results 

P2

(dBm) 

P3

(dBm)

P4

(dBm) 

PS

(dBm) 

PI

(dBm) 

PS /P4

(dB) 

SNR 

(dB) 

INRTOV

(dB)

INRTOV

(dB) 

-47.8 -38.4 -44.4 -38.9 -47.1 5.5 8.9 0.7 0.5 

-47.7 -35.4 -41.2 -35.7 -42.3 5.5 12.0 5.4 5.1 

-47.8 -32.6 -38.1 -32.7 -38.6 5.4 15.0 9.2 8.7 

. 1 INR ESR SNR

SNR

P P P

P SNR

N I

S

eff + + ⋅ = + + ′ =

ε
52 

Figure B-7. Theoretical and measured BER for Gaussian noise interference. 

Figure B-8. Theoretical and measured SER for Gaussian noise interference. 
53 

APPENDIX C: THEORETICAL ANALYSIS OF GATED GAUSSIAN NOISE 

This appendix provides theoretical analyses of gated Gaussian noise expressed mathematically as 

where z(t) is a Gaussian noise random process with an ultra-wide transmission bandwidth (BUWB) 

much greater than the victim receiver bandwidth (BDTV), n(t) is a zero-mean white Gaussian noise 

random process, hBPF(t) is the impulse response of a band-pass filter that defines BUWB , and * is 

the convolutional operator. The ideal gating function is described mathematically as 

 

and S1 and S2 refer to gated-on and gated-off states, respectively. The complex-baseband (CBB) 

representation, denoted by ˆ, of u(t) is modeled as 

 

where zˆ(t) is a complex Gaussian-distributed random variable with zero-mean. The variance of 

zˆ(t) is 2 2 σ zˆ = 2σ , where σ

2

 is the variance of the real and imaginary parts. The following 

amplitude probability distribution (APD) and power spectral density (PSD) expressions are 

derived in terms of uˆ(t). 

C.1. Amplitude Probability Distribution 

Computation of the APD for gated Gaussian noise begins with the total probability expression 

(C-1) 

where ℘ represents probability, A = uˆ(t) is the amplitude random variable which takes on 

values of a ranging from 0 to ∞ , ℘(Sk) represents the probability of being in state Sk , and 

( | ) ℘ A ≤ a Sk represents the conditional probability of A ≤ a given the state Sk . 

Amplitudes are Rayleigh distributed in state S1 giving the probability density function (PDF) 

 

( ) ( | ) ( ) ( | ) ( ) , 1 1 2 2 ℘ A ≤ a =℘ A ≤ a S ℘ S +℘ A ≤ a S ℘ S

. 2 ( | ) exp 2

2

1 2 ⎟

⎟

⎠

⎞

⎜

⎜

⎝

⎛ − = σ σ

a a

q a S

( ) ( ) ( ; , ) ( ( ) ( )) ( ; , ) , on BPF T on u t = z t g t T τ = n t ∗ h t g t τ

( )

( ) ⎩

⎨

⎧

≤ <

≤ < = ∑ − =

∞

=−∞ S t T

S t

g t T R t kT R t

on

on

on

k

on on τ

τ

τ τ τ

0 :

1 : 0

( ; , ) ( ; ) , where ( ; )

2

1

ˆ( ) ˆ( ) ( ; , ) , T on u t = z t g t τ
54 

The corresponding cumulative distribution function (CDF) is 

Similarly, the amplitude is always 0 in state S2 giving the PDF

where δ(a) is the delta function. The corresponding CDF is acquired by integrating the PDF over 

all amplitudes which yields the step function U(a). Recall that a ≥ 0, hence U(a) = 1 yielding 

Probabilities of being in each state are expressed in terms of the fractional on-time (ζ) 

Substituting these expressions into the total probability expression (C-1) yields the CDF

The corresponding APD is obtained by subtracting the CDF from 1 

(C-2) 

Figure C-1 provides APDs of normalized (σ

2

 = 1) gated Gaussian noise with 

ζ = {1, 0.5, 0.25, 0.125, 0.0625} in an ultra-wide transmission bandwidth. 

Peak-to-average ratio (P/A) is computed from the peak and root-mean-square (rms) amplitudes. 

Peak amplitude (apk) is defined by the percentile ρ. Replacing ℘(A > a) with ρ and a with apk in 

equation (C-2) and solving for apk yields 

This expression is only valid when ζ ≥ ρ. 

. 2 ( | ) 1 exp 2

2

1 ⎟

⎟

⎠

⎞

⎜

⎜

⎝

⎛ − ℘ ≤ = − σ

a A a S

( | ) ( ) , 2 q a S = δ a

( ) ; ( ) (1 ) . ℘ S1 = ζ ℘ S2 = − ζ

. 2 ( ) 1 exp 2

2

⎟

⎟

⎠

⎞

⎜

⎜

⎝

⎛ − ℘ ≤ = − σ

ζ a A a

= σ ln(ζ ρ) . apk

( | ) 1 . ℘ A ≤ a S2 =

. 2 ( ) exp 2

2

⎟

⎟

⎠

⎞

⎜

⎜

⎝

⎛ − ℘ > = σ

ζ a A a
55 

Rms amplitude is found by substituting the probability densities given previously into the 

derivative of (C-1) with respect to a to obtain 

and using this PDF to calculate rms amplitude 

Finally, the expression for P/A is 

Figure C-2 provides P/A as a function of ζ for gated noise in the ultra-wide transmission 

bandwidth; peak definitions considered in Figure C-2 are ρ = {0.001, 0.01, 0.1, 1.0} %. 

C.2. Power Spectral Density 

Derivation of the PSD for gated Gaussian noise begins with the autocorrelation function 

where E{ } denotes expectation and *

 denotes conjugation. Pulling the deterministic gating 

function out of the expectation gives 

Expressing the gating function as a Fourier series 

yields 

(1 ) ( ) , 2 ( ) ( | ) ( ) ( | ) ( ) exp 2

2

1 1 2 2 2 a

a a

q a q a S S q a S S ζ δ

σ σ

ζ + − ⎟

⎟

⎠

⎞

⎜

⎜

⎝

⎛ − = ℘ + ℘ =

( , ) ( ) ( ) ( ) . ˆˆ

*

ˆ ˆ τ τ τ uu Rzz R t t + = g t g t +

( ) g t ( ) j kt T dt

T g t c j kt T c

T

k

k

∑ k ∫ = = −

∞

=−∞ 0

( ) exp 2 / 1 ( ) exp 2π / , π

( , ) exp( )( ) 2 ( ) / exp 2 / ( ) . ˆˆ

*

ˆ ˆ τ π π τ τ zz

l k

Ruu t t + = ∑ ∑clck j l − k t T − j k T R

∞

=−∞

∞

=−∞

( , ) { ˆ( ) ˆ ( )} , * Rˆ ˆ t t +τ = E u t u t + τ uu

( ) . ln /

2

a ζ

a

P A

rms

pk ζ ρ = ⎟

⎟

⎠

⎞

⎜

⎜

⎝

⎛ =

( ) .

0

2 = = σ ζ ∫

∞

arms a q a da
56 

The first complex-exponential term causes the autocorrelation to be time-varying. This variation 

is periodic, in that 

and is removed by averaging over the gating period. The resulting time-averaged autocorrelation 

function is 

which evaluates to 

The PSD is derived from the Fourier transform of the time-averaged autocorrelation function 

Substitution yields the following expression for the PSD of gated Gaussian noise 

Note that Snn(f) is constant, yielding 

where n0 is the power density of the underlying white Gaussian process and HLPF(f) is the CBB 

representation of HBPF(f). This simplifies the PSD expression 

 

In this experiment we assume the transmission filter, HLPF(f), is constant over the bandwidth of 

the victim receiver. Hence, the PSD of gated noise is constant for all frequencies considered. 

( ) ( ) ( ) . ˆˆ

2

ˆ ˆ S f T

k S f c f zz

k

uu k = ∑ + ∗

∞

=−∞

δ

( , ) ( , ) , Ruˆuˆ t t +τ = Ruˆuˆ t + T t +τ + T

( )

⎪

⎪

⎪

⎩

⎪

⎪

⎪

⎨

⎧

≠

− =

=

∑

∞

=−∞

0 ( ) .

exp 2 / ( ) ( )

( )

ˆˆ

2

ˆ ˆ

l k

c j k T R l k

R

zz

k

k

uu

π τ τ

τ

( ) ( ) ( ) . 2

2

ˆ ˆ 0 H f T

k S f n c f LPF

k

uu = ∑ k + ∗

∞

=−∞

δ

( ) ( ) exp( ) 2 . ˆ ˆ ∫ ˆ ˆ

∞

−∞

S f = R τ − j π fτ dτ uu uu

( ) ( ) , 2

ˆˆ 0 S f n H f zz = LPF

( ) ( ) ∫ ∑ ∑ ∫ = + = − −

∞

=−∞

∞

=−∞

T T

zz

l

k

k

uu uu l j l k t T dt

T

R t t dt c c j k T R

T

R

0 0

ˆˆ

*

ˆ ˆ ˆ ˆ exp 2 ( ) / , 1 ( , ) exp 2 / ( ) 1 (τ ) τ π τ τ π
57 

Figure C-1. Theoretical APDs of gated noise in BUWB. 

Figure C-2. Theoretical P/A of gated noise in BUWB. 
58 

APPENDIX D: CHARACTERIZATION MEASUREMENTS

This appendix provides a description of measurement setup and signal characterization 

measurements that complement those in Section 3.

D.1. Measurement Setup 

Interference signals were measured under optimal conditions at the radio frequency (RF) output 

of the vector signal generator (VSG) as described in Figure D-1. The VSG was set up with the 

procedures described in Appendix B of Part 1 [6]. Measurements at RF were made with the 

vector signal analyzer (VSA) and digital oscilloscope (DO). 

Figure D-1. Setup for RF signal characterization measurements. 

The gated-noise signals, GN-02 – GN-17, were simulated by applying different gating signals to 

the continuous-noise signal, GN-01. This ensured that voltages of all signals were identical when 

gated on. Gated-noise signals, generated in hardware with the setup described by Figure C-2 in 

Part 1, were also measured to verify corresponding VSG-generated signals. Characteristics of the 

hardware-generated signals matched those of the VSG-generated signals and therefore are not 

included in this report. 

For VSA characterization measurements at RF, the VSG output level was set to -28.19 dBm for 

GN-01 through GN-17 and -27.17 dBm for GN(MB)-01 through GN(MB)-09. At these levels, 

the VSG generated the “continuous” signals, GN-01 and GN(MB)-01, at an average power of 

approximately -45 dBm in a 36-MHz bandwidth at the output of the cable. This optimally 

utilized the dynamic range of the VSA as discussed in Appendix E of Part 1. VSA instrument 

settings are summarized in Table D-1. 

Table D-1. RF VSA Measurement Settings 

Post-Processing 

Bandwidths (MHz) Span (MHz) Number of 

Samples 

Center 

Frequency 

(MHz) 

Input Range 

(dBm) 

36, 19.51, 10 36 > 360,000 

1 4.5 > 450,000 

0.1 0.5625 > 562,500 

3820 -30 
59 

DO measurements at the maximum sample rate, i.e., 20 GSps, provided real time-domain 

representations of RF signals. DO measurements were made with the VSG output level set to a 

higher value, i.e., 0 dBm, to compensate for low DO sensitivity at the maximum sample rate. 

Interference signals were measured under TOV operational conditions at the IF output of the 

low-noise block downconverter (LNB) with the setup described in Figure 20 of Part 1. The 

simplified block diagram of those components that affect the IF signal characterization 

measurements are shown in Figure D-2. Bandpass filter BPF1 has a 1-dB bandwidth equal to 40 

MHz. The VSG output level was set to INRTOV. Measurements at IF were made with the VSA 

only. VSA settings for IF measurements were the same as those used for RF measurements 

described in Table D-1, except the center frequency was set to 1330 MHz. 

Figure D-2. Simplified setup for IF signal characterization measurements. 

D.2. Results 

This subsection provides amplitude statistics and time series of the gated-noise signals. Odd 

numbered plots in Figures D-3 – D-54 provide RF measurement results organized as: 

(a) Real time series measured with DO and amplitude time series measured with the VSA 

and band-limited to BDTV = 19.51 MHz. 

(b) APDs measured with a VSA and band-limited to 36, 10, 1, and 0.1 MHz as well as BDTV. 

Even numbered plots in Figures D-3 – D-54 provide IF measurement results organized as: 

(a) Amplitude time series measured with the VSA and band-limited to BDTV. 

(b) APDs measured with the VSA and band-limited to BDTV. 

Table D-2 provides peak-to-average (P/A) values for the gated-noise signals measured at RF and 

band-limited to various bandwidths in post-measurement processing. The shaded cells highlight 

signals with Rayleigh-distributed amplitudes. Ultra-wide transmission bandwidth (BUWB) limits 

for P/A were derived in Appendix C. 

Table D-3 provides P/A values for gated-noise signals measured at IF under TOV operational 

conditions and band-limited to BDTV in post-measurement processing. 
60 

 Table D-2. RF P/A (dB) of GN and GN(MB) Signals Band-Limited to Different Bandwidths 

Type Index BUWB 36.0 MHz BDTV 10.0 MHz 1.0 MHz 0.1 MHz 

01 9.6 9.6 9.6 9.8 9.8 9.0 

02 12.3 9.7 9.9 9.5 9.7 9.6 

03 14.9 11.0 9.7 9.8 9.5 8.9 

04 17.5 13.1 11.5 9.4 9.5 10.1 

05 20.1 15.9 14.2 11.7 9.8 9.1 

06 12.3 11.8 12.2 11.2 9.5 9.3 

07 14.9 14.4 14.6 13.9 9.6 9.9 

08 17.5 16.8 17.3 16.5 9.7 9.4 

09 20.1 19.8 19.6 18.9 11.7 9.2 

10 12.3 12.5 12.4 12.5 11.1 10.1 

11 14.9 15.1 15.0 14.8 13.6 9.8 

12 17.5 17.9 17.6 17.6 16.3 9.4 

13 20.1 20.3 20.3 20.0 18.8 11.0 

14 12.3 12.6 12.3 12.2 12.3 10.3 

15 14.9 15.3 15.1 14.8 14.8 14.1 

16 17.5 17.4 17.8 17.9 17.6 15.7 

GN 

17 20.1 19.9 20.1 20.0 19.9 16.4 

01 10.6 10.5 10.5 10.1 9.6 9.7 

02 14.8 14.4 14.7 14.6 9.8 9.5 

03 14.8 14.7 14.6 14.5 11.6 9.5 

04 18.0 17.5 18.0 17.6 12.7 9.7 

05 18.0 17.6 17.9 17.5 14.7 9.5 

06 18.0 17.6 17.8 17.6 16.5 10.6 

07 20.3 20.1 20.2 19.7 15.0 9.4 

08 20.3 20.0 20.1 19.8 16.8 9.0 

GN 

(MB) 

09 20.3 20.1 19.9 19.5 19.0 15.0 *

Shaded cells highlight Rayleigh-amplitude statistics.
61 

Table D-3. IF P/A (dB) of GN and GN(MB) Signals at INRTOV and Band-Limited to BDTV

Type Index SNR ≈ 9 dB SNR ≈ 12 dB SNR ≈ 15 dB 

01 9.6 9.6 9.4 

02 9.8 9.8 9.9 

03 9.6 9.5 9.5 

04 10.4 11.1 11.1 

05 12.0 13.2 13.6 

06 10.8 11.1 11.7 

07 12.1 13.2 13.8 

08 14.1 15.2 16.4 

09 16.1 17.8 18.8 

10 11.2 11.4 11.8 

11 11.9 13.1 13.7 

12 13.0 14.6 15.8 

13 13.5 16.2 17.5 

14 10.7 11.5 12.0 

15 11.4 12.8 13.6 

16 12.0 13.8 15.3 

GN 

17 11.9 14.3 16.6 

01 10.2 10.2 10.3 

02 12.1 13.3 14.3 

03 12.0 13.4 13.9 

04 14.0 16.2 16.7 

05 13.5 15.4 16.4 

06 12.6 14.6 15.8 

07 15.0 17.8 18.7 

08 14.3 16.5 17.9 

GN 

(MB) 

09 12.7 15.2 17.4 *

Shaded cells highlight Rayleigh-amplitude statistics.
62 

Figure D-3. RF measurements of GN-01, Gaussian noise. 
63 

Figure D-4. IF measurements of GN-01 at INRTOV.
64 

Figure D-5. RF measurements of GN-02 (τon = 10 ns, ζ = 0.5000). 
65 

Figure D-6. IF measurements of GN-02 at INRTOV. 
66 

Figure D-7. RF measurements of GN-03 (τon = 10 ns, ζ = 0.2500). 
67 

Figure D-8. IF measurements of GN-03 at INRTOV. 
68 

Figure D-9. RF measurements of GN-04 (τon = 10 ns, ζ = 0.1250). 
69 

Figure D-10. IF measurements of GN-04 at INRTOV.
70 

Figure D-11. RF measurements of GN-05 (τon = 10 ns, ζ = 0.0625). 
71 

Figure D-12. IF measurements of GN-05 at INRTOV.
72 

Figure D-13. RF measurements of GN-06 (τon = 100 ns, ζ = 0.5000). 
73 

Figure D-14. IF measurements of GN-06 at INRTOV.
74 

Figure D-15. RF measurements of GN-07 (τon = 100 ns, ζ = 0.2500). 
75 

Figure D-16. IF measurements of GN-07 at INRTOV.
76 

Figure D-17. RF measurements of GN-08 (τon = 100 ns, ζ = 0.1250). 
77 

Figure D-18. IF measurements of GN-08 at INRTOV.
78 

Figure D-19. RF measurements of GN-09 (τon = 100 ns, ζ = 0.0625). 
79 

Figure D-20. IF measurements of GN-09 at INRTOV.
80 

Figure D-21. RF measurements of GN-10 (τon = 1000 ns, ζ = 0.5000). 
81 

Figure D-22. IF measurements of GN-10 at INRTOV.
82 

Figure D-23. RF measurements of GN-11 (τon = 1000 ns, ζ = 0.2500). 
83 

Figure D-24. IF measurements of GN-11 at INRTOV.
84 

Figure D-25. RF measurements of GN-12 (τon = 1000 ns, ζ = 0.1250). 
85 

Figure D-26. IF measurements of GN-12 at INRTOV.
86 

Figure D-27. RF measurements of GN-13 (τon = 1000 ns, ζ = 0.0625). 
87 

Figure D-28. IF measurements of GN-13 at INRTOV.
88 

Figure D-29. RF measurements of GN-14 (τon = 10000 ns, ζ = 0.5000). 
89 

Figure D-30. IF measurements of GN-14 at INRTOV.
90 

Figure D-31. RF measurements of GN-15 (τon = 10000 ns, ζ = 0.2500). 
91 

Figure D-32. IF measurements of GN-15 at INRTOV.
92 

Figure D-33. RF measurements of GN-16 (τon = 10000 ns, ζ = 0.1250). 
93 

Figure D-34. IF measurements of GN-16 at INRTOV.
94 

Figure D-35. RF measurements of GN-17 (τon = 10000 ns, ζ = 0.0625). 
95 

Figure D-36. IF measurements of GN-17 at INRTOV.
96 

Figure D-37. RF measurements of GN(MB)-01 (b = 1, d = 1). 
97 

Figure D-38. IF measurements of GN(MB)-01 at INRTOV.
98 

Figure D-39. RF measurements of GN(MB)-02 (b = 3, d = 1). 
99 

Figure D-40. IF measurements of GN(MB)-02 at INRTOV.
100 

Figure D-41. RF measurements of GN(MB)-03 (b = 3, d = 2). 
101 

Figure D-42. IF measurements of GN(MB)-03 at INRTOV.
102 

Figure D-43. RF measurements of GN(MB)-04 (b = 7, d = 1). 
103 

Figure D-44. IF measurements of GN(MB)-04 at INRTOV.
104 

Figure D-45. RF measurements of GN(MB)-05 (b = 7, d = 2). 
105 

Figure D-46. IF measurements of GN(MB)-05 at INRTOV.
106 

Figure D-47. RF measurements of GN(MB)-06 (b = 7, d = 6). 
107 

Figure D-48. IF measurements of GN(MB)-06 at INRTOV.
108 

Figure D-49. RF measurements of GN(MB)-07 (b = 13, d = 1). 
109 

Figure D-50. IF measurements of GN(MB)-07 at INRTOV.
110 

Figure D-51. RF measurements of GN(MB)-08 (b = 13, d = 2). 
111 

 Figure D-52. IF measurements of GN(MB)-08 at INRTOV. 
112 

Figure D-53. RF measurements of GN(MB)-09 (b = 13, d = 12). 
113 

 Figure D-54. IF measurements of GN(MB)-09 at INRTOV.