Performance Evaluation of Low Density Parity Check Forward Error Correction in an Aeronautical Flight Environment

ITC/USA 2014 Conference Proceedings / The Fiftieth Annual International Telemetering Conference and Technical Exhibition / October 20-23, 2014 / Town and Country Resort & Convention Center, San Diego, CAIn some flight test scenarios the telemetry link is noise limited at long slant ranges or during signal fade events caused by antenna pattern nulls. In these situations, a mitigation technique such as forward error correction (FEC) can add several decibels to the link margin. The particular FEC code discussed in this paper is a variant of a low-density parity check (LDPC) code and is coupled with SOQPSK modulation in the hardware tested. This paper will briefly cover lab testing of the flight-ready hardware then present flight test results comparing a baseline uncoded telemetry link with a LDPC-coded telemetry link. This is the first known test dedicated to this specific FEC code in a real-world test environment with flight profile tailored to assess the viability of an LDPC-coded telemetry link.International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection

PERFORMANCE TRADE-OFFS WHEN IMPLEMENTING TURBO PRODUCT CODE FORWARD ERROR CORRECTION FOR AIRBORNE TELEMETRY

ITC/USA 2005 Conference Proceedings / The Forty-First Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2005 / Riviera Hotel & Convention Center, Las Vegas, NevadaHardware implementing forward error correction (FEC) is currently available for utilization by the airborne telemetry system designer. This paper will discuss the potential benefits along with drawbacks when using this technology. Laboratory testing is supplemented with real-world flight testing. Performance results comparing FEC and non-FEC systems are presented for both IRIG-106 Pulse Code Modulation/Frequency Modulation, PCM/FM, (or Continuous Phase Frequency Shift Keying, CPFSK, with filtering, or ARTM Tier 0) and Shaped Offset Quadrature Phase Shift Keying, Telemetry Group version (SOQPSK-TG or ARTM Tier I) waveforms.International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection

AN INITIAL LOOK AT ADJACENT BAND INTERFERENCE BETWEEN AERONAUTICAL MOBILE TELEMETRY AND LONG-TERM EVOLUTION WIRELESS SERVICE

With National Telecommunications & Information Administration (NTIA) Advanced Wireless Services (AWS-3) auction of frequencies in the 1695-1710 MHz, 1755-1780MHz, and 2155- 2180MHz bands, users of the Aeronautical Mobile Telemetry (AMT) band from 1755- 1850MHz, known as Upper L-Band, could be greatly affected. This paper takes an initial look at how the 1755-1780MHz band will be used by the cellular carriers and presents some preliminary testing results of adjacent channel (band) interference that could be experienced by AMT users. This paper should be considered as the stepping off point for future interference discussions, required analysis, and further testing.International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection

ARTM TIER II WAVEFORM PERFORMANCE

International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, NevadaOne of the charters of the Advanced Range Telemetry (ARTM) program was to develop more spectrally efficient waveforms while trying to maintain similar performance to the legacy waveform, Pulse Code Modulation/Frequency Modulation (PCM/FM). The first step toward this goal was the ARTM Tier I family of waveforms which include Feher patented, quadrature phase shift keying, -B version (FQSPKB) and shaped offset quadrature phase shift keying, Telemetry Group version (SOQPSK-TG). The final step was development of Tier II, an even more spectrally efficient waveform, multi-h Continuous Phase Modulation (CPM). This paper characterizes the performance of this waveform when applied in an airborne telemetry environment and, where appropriate, comparisons are made with existing Tier 0 and Tier I waveforms. The benefits, drawbacks, and trade-offs when applying this waveform in an airborne environment will also be discussed.International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection

ADVANCED RANGE TELEMETRY (ARTM) TIER I COMPATIBLE DEMODULATOR TESTING AND RESULTS

International Telemetering Conference Proceedings / October 21, 2002 / Town & Country Hotel and Conference Center, San Diego, CaliforniaThe Nova HYPERMOD demodulator operates in three modes, the classic pulse-code modulation/frequency modulation (PCM/FM), sometimes known as continuous phase frequency shift keying (CPFSK) mode, shaped offset quadrature phase shift keying (SOQPSK) mode, and continuous phase modulation (CPM) mode. Of interest to this paper is SOQPSK mode which is a waveform similar to the Advanced Range Telemetry (ARTM) Tier I waveform, Feher’s Quadrature Phase Shift Keying, B version (FQPSK-B) revision (Rev) A1. Also considered is another variant, FQPSK-JR. This paper will outline the cross compatibility and resynchronization speed of these waveforms based upon ARTM-adopted demodulator performance tests. The results of these laboratory tests comparing the HYPERMOD demodulator, the enhanced Tier I demodulator, and the current Tier I reference demodulator, both from RF Networks, will be presented.International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection

ARTM CPM Receiver/Demodulator Performance: An Update

ITC/USA 2013 Conference Proceedings / The Forty-Ninth Annual International Telemetering Conference and Technical Exhibition / October 21-24, 2013 / Bally's Hotel & Convention Center, Las Vegas, NVSince the waveform was first developed by the Advanced Range Telemetry Program (ARTM) and adopted by the Range Commanders Council Telemetry Group (RCC/TG), receiver/demodulators for the ARTM Continuous Phase Modulation (CPM) waveform have undergone continued development by several hardware vendors to boost performance in terms of phase noise, detection performance, and resynchronization time. These same results were initially presented at the International Telemetry Conference (ITC) 2003 when hardware first became available supporting this waveform, at the time called ARTM Tier II. This paper reexamines the current state of the art performance of ARTM CPM receiver/demodulators available in the marketplace today.International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection

MODULATOR IMBALANCE EFFECTS ON THE FQPSK AIRBORNE TELEMETRY LINK

International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, CaliforniaWhen designing transmitters for quadrature modulation schemes, the designer always tries to achieve good balance and symmetry of the in-phase (I) and quadrature (Q) branches of the modulator in terms of amplitude, phase, and offsets. Perfect balance between modulators is ideal but rarely if ever achieved. The Advance Range Telemetry (ARTM) program has placed indirect specifications on the remnant carrier and sideband levels which are controlled by modulator imbalance. These specifications will govern the ARTM programs first generation of Feher’s patented quadrature phase shift keying, version B (FQPSK-B) [9] airborne telemetry transmitters. The ARTM Program has also adopted test procedures for quantifying these modulation imbalances. This paper looks at the effects of modulator imbalances on spectral occupancy and bit error probability of the airborne telemetry link. It also outlines how these imbalances influence the levels in one of the ARTM specifications. Recommendations are presented based on the measured data for higher bit rate telemetry systems.International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection

Adjacent Channel Interference Criteria for Aeronautical Telemetry Operations with the Tactical Targeting Network Technology System

ITC/USA 2009 Conference Proceedings / The Forty-Fifth Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2009 / Riviera Hotel & Convention Center, Las Vegas, NevadaThis paper will provide recommended channel spacing requirements when the Tactical Targeting Network Technology (TTNT) System is utilized in conjunction with airborne telemetry systems at airborne test ranges. The recommendation will be in the form of an equation similar in form to the adjacent channel interference (ACI) equation currently in the Telemetry Standard IRIG-106. Test results will be presented to support this recommendation.International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection

WHY ARE WE HATIN’ ON ARTM CPM?

Why hasn’t the Aeronautical Mobile Telemetry community adopted IRIG 106 compliant ARTM CPM as their preferred waveform for the transmission of telemetry data? Telemetry receivers in the market place today exhibit gains in detection efficiency and resynchronization speed that far exceed products of just a few years ago. Past papers have shown the link performance comparison between the new waveform standard SOQPSK-TG and ARTM CPM has narrowed since ARTM CPM was first standardized. This paper will present the latest performance comparison between these two waveforms during a controlled test throughout various flight conditions. The testing is presented and performance comparisons are made between the waveforms. This comparison will use traditional methods combined with several new performance metrics presented in this paper. To conclude, Link Availability, the measure of overall link performance is presented illustrating how closely these waveforms perform.International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection

An Initial Look at Adjacent Band Interference Between Aeronautical Mobile Telemetry and Long-Term Evolution Wireless Service

With National Telecommunications & Information Administration (NTIA) Advanced Wireless Services (AWS-3) auction of frequencies in the 1695-1710 MHz, 1755-1780MHz, and 2155- 2180MHz bands, users of the Aeronautical Mobile Telemetry (AMT) band from 1755- 1850MHz, known as Upper L-Band, could be greatly affected. This paper takes an initial look at how the 1755-1780MHz band will be used by the cellular carriers and presents some preliminary testing results of adjacent channel (band) interference that could be experienced by AMT users. This paper should be considered as the stepping off point for future interference discussions, required analysis, and further testing.International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection