Comparison of jamming robustness of airborne networking waveforms
17 Oct 2005-pp 2119-2125
TL;DR: Quantitative results comparing the performance of three representative waveforms against several jamming threats, including tone, partial-band, and frequency-follower jamming, are presented, and techniques to improve their robustness to the interference are considered.
Abstract: Many future airborne networks will be built around the software-defined joint tactical radio system (JTRS). Because of the programmability of JTRS, planners of these networks will have a great deal of flexibility in their selection of waveforms. There can be a wide variation in the properties of the candidate waveforms, such as data rate, spectral efficiency, latency, and protection against jamming. In order to choose those waveforms which best meet mission needs, these capabilities must be understood. Because of the nodes' high altitudes and use of omnidirectional antennas, airborne networks can be particularly susceptible to jamming. In this paper, we investigate the performance of three representative waveforms in the presence of hostile jamming. One waveform is based on orthogonal frequency division multiplexing (OFDM), a multicarrier modulation technique. The second uses single-carrier direct-sequence spread-spectrum modulation. Finally, a waveform based on the legacy Link 16 system, which uses a combination of frequency-hop and direct-sequence spread spectrum, is considered. Quantitative results comparing the performance of these waveforms against several jamming threats, including tone, partial-band, and frequency-follower jamming, are presented, and techniques to improve their robustness to the interference are considered.
Citations
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01 Nov 2008
TL;DR: An analytic upper bound on the probability of symbol error of C CSK is derived for the 32-chip CCSK sequence chosen for JTIDS and is compared with that obtained by Monte Carlo simulation for additive white Gaussian noise.
Abstract: Cyclic code-shift keying (CCSK) is the baseband symbol modulation scheme used by Joint Tactical Information Distribution System (JTIDS), the communication terminal of Link-16. Since CCSK is non-orthogonal, an analytic evaluation of its performance in terms of probability of symbol error is nontrivial. In this paper, an analytic upper bound on the probability of symbol error of CCSK is derived for the 32-chip CCSK sequence chosen for JTIDS. The probability of symbol error obtained with the analytic method is compared with that obtained by Monte Carlo simulation for additive white Gaussian noise. The results show that the analytic method yields a tight upper bound. In addition to the 32-chip CCSK sequence chosen for JTIDS, a new 32-chip CCSK sequence with a smaller maximum off-peak cross-correlation is obtained and evaluated both analytically and by Monte Carlo simulation. The results obtained for the new CCSK sequence compare favorably with the sequence chosen for JTIDS.
27 citations
01 Nov 2008
TL;DR: This paper investigates the probability of symbol error of a JTIDS/Link-16-type waveform for both the single- and the double-pulse structure transmitted over a slow, flat Nakagami fading channel in the presence of pulsed-noise interference (PNI).
Abstract: The Joint Tactical Information Distribution System (JTIDS) is the communication terminal of Link-16. JTIDS is a hybrid direct sequence/frequency-hopping spread spectrum system and features Reed-Solomon codes for channel coding, cyclic code-shift keying for 32-ary symbol modulation, minimum-shift keying for chip modulation, symbol interleaving, chip sequence scrambling and random jittering for transmission security, and a double-pulse structure for diversity. Assuming that coherent chip demodulation is practical, we investigate the probability of symbol error of a JTIDS/Link-16-type waveform for both the single- and the double-pulse structure transmitted over a slow, flat Nakagami fading channel in the presence of pulsed-noise interference (PNI) in this paper. In general, the results show that the double-pulse structure always outperforms the single-pulse structure, whether the PNI is present or not and whether the channel is fading or not. Furthermore, barrage noise interference has the most effect in degrading performance when signal-to-interference ratio (SIR) is small. When SIR is large, PNI with a smaller fraction of time that interference is on causes the greatest degradation.
24 citations
01 Dec 2008
TL;DR: The results show that barrage noise interference (BNI) has the most effect in degrading JTIDS's performance when signal-to interference ratio (SIR) is small, whereas pulsed-noise interference with a smaller fraction of time that interference is on causes the greatest degradation when SIR is large, whether the channel is fading or not.
Abstract: : Link-16 is a tactical data link. It provides presumably secure and jam-resistant tactical information for land, sea, and air platforms. The communication terminal of Link-16 is called Joint Tactical Information Distribution System (JTIDS) and features Reed-Solomon (RS) coding, symbol interleaving, cyclic code-shift keying (CCSK) for M-ary symbol modulation, minimum-shift keying (MSK) for chip modulation, and combined frequency-hopping and direct sequence spread spectrum for transmission security. In this dissertation, the performance of a JTIDS/Link-16-type waveform in both additive white Gaussian noise (AWGN) and narrowband interference transmitted over a slow, flat Nakagami fading channel is investigated. In general, the results show that barrage noise interference (BNI) has the most effect in degrading JTIDS's performance when signal-to interference ratio (SIR) is small, whereas pulsed-noise interference with a smaller fraction of time that interference is on causes the greatest degradation when SIR is large, whether the channel is fading or not. In addition, two modified JTIDS/Link-16- compatible systems are proposed and evaluated. The first system uses errors-and-erasures decoding (EED) in place of errors only RS decoding, whereas the second system employs a new 32-chip CCSK sequence instead of the 32-chip CCSK sequence chosen for JTIDS. The results show that EED outperforms errors-only RS decoding in all cases and the probability of symbol error obtained for the new CCSK sequence compares favorably with the sequence chosen for JTIDS.
13 citations
Cites background or methods from "Comparison of jamming robustness of..."
...Previously, the evaluation has been done by simulation [9],[10],[13]....
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...Additional research related to the performance of JTIDS is presented in [13]....
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01 Sep 2015
TL;DR: In this article, an interference model is built and incorporated into an aeronautical communication link design, where spread spectrum techniques are employed to mitigate the interference effects, which can be categorized into unintentional and intentional interference.
Abstract: Communication link maintenance is crucial for aeronautical systems operations. To ensure the reliability, robustness, and security of aeronautical communication links; we investigate various types of interference in aeronautical communication systems, which can be categorized into unintentional and intentional interference. An interference model is built and incorporated into an aeronautical communication link design, where spread spectrum techniques are employed to mitigate the interference effects. To ensure comprehensive communication link quality-of-services, a direct-sequence spread spectrum (DSSS) and frequency-hopping spread spectrum (FHSS) are investigated and compared. Turbo coding is employed in conjunction with DSSS/FHSS for overall interference mitigation and performance evaluations. As a practical use case, the Rician fading channel is evaluated when analyzing the data link performances for three phases of air traffic surface management: taxing, takeoff/landing, and departure/approach scenarios. The results demonstrate consideration for future NextGen avionics designs for security and maintenance of communication links between the aircraft and air traffic control operations.
10 citations
Cites background from "Comparison of jamming robustness of..."
...BER quantifies the quality of end-to-end data transmission in wireless environments, where signals are often distorted by wireless channels and disrupted by intentional or unintentional interferences....
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...The results demonstrate consideration for future NextGen avionics designs for security and maintenance of communication links between the aircraft and air traffic control operations....
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TL;DR: A new 32‐chip CCSK starting sequence which has a smaller maximum off‐peak cross‐correlation value than the current JTIDS starting sequence is proposed and evaluated both analytically and by simulation.
Abstract: Cyclic code-shift keying (CCSK) is the baseband 32-ary symbol modulation scheme used by the Joint Tactical Information Distribution System (JTIDS), the communication terminal for Link-16. CCSK is not orthogonal and an analytic expression for the probability of symbol error for CCSK has thus far been elusive. In this paper, an analytic upper bound on the probability of symbol error of CCSK is derived for the 32-chip CCSK starting sequence chosen for JTIDS. The analytically obtained probability of symbol error is compared with two different Monte Carlo simulations for additive white Gaussian noise. The results of both simulations match the analytic results very well and show that the analytic method yields a tight upper bound. A new 32-chip CCSK starting sequence which has a smaller maximum off-peak cross-correlation value than the current JTIDS starting sequence is proposed and evaluated both analytically and by simulation. The results obtained for the new CCSK starting sequence compare favorably with the CCSK starting sequence chosen for JTIDS. Published in 2010 by John Wiley & Sons, Ltd.
Cyclic code shift keying is used in important military communications systems designed for jamming resistance. This paper provides the most accurate analysis and simulation of CCSK performance to date in addition to a proposed improvement over the CCSK employed in the widely used Link-16 tactical communications system.
(This article is a U.S. Government work and is in the public domain in the U.S.A.)
7 citations
References
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TL;DR: A rapid synchronization method is presented for an orthogonal frequency-division multiplexing (OFDM) system using either a continuous transmission or a burst operation over a frequency-selective channel.
Abstract: A rapid synchronization method is presented for an orthogonal frequency-division multiplexing (OFDM) system using either a continuous transmission or a burst operation over a frequency-selective channel. The presence of a signal can be detected upon the receipt of just one training sequence of two symbols. The start of the frame and the beginning of the symbol can be found, and carrier frequency offsets of many subchannels spacings can be corrected. The algorithms operate near the Cramer-Rao lower bound for the variance of the frequency offset estimate, and the inherent averaging over many subcarriers allows acquisition at very low signal-to-noise ratios (SNRs).
3,492 citations
TL;DR: It is shown, and confirmed by simulation, that to maintain signal-to-interference ratios of 20 dB or greater for the OFDM carriers, offset is limited to 4% or less of the intercarrier spacing.
Abstract: This paper discusses the effects of frequency offset on the performance of orthogonal frequency division multiplexing (OFDM) digital communications. The main problem with frequency offset is that it introduces interference among the multiplicity of carriers in the OFDM signal. It is shown, and confirmed by simulation, that to maintain signal-to-interference ratios of 20 dB or greater for the OFDM carriers, offset is limited to 4% or less of the intercarrier spacing. Next, the paper describes a technique to estimate frequency offset using a repeated data symbol. A maximum likelihood estimation (MLE) algorithm is derived and its performance computed and compared with simulation results. Since the intercarrier interference energy and signal energy both contribute coherently to the estimate, the algorithm generates extremely accurate estimates even when the offset is far too great to demodulate the data values. Also, the estimation error depends only on total symbol energy so it is insensitive to channel spreading and frequency selective fading. A strategy is described for initial acquisition in the event of uncertainty in the initial offset that exceeds 1/2 the carrier spacing, the limit of the MLE algorithm. >
2,475 citations
TL;DR: The authors present an overview of new multiple access schemes based on a combination of code division and multicarrier techniques, such as multicarrier code-division multiple access (MC-CDMA), multicarriers direct sequence CDMA, and multitone CDMA.
Abstract: The authors present an overview of new multiple access schemes based on a combination of code division and multicarrier techniques, such as multicarrier code-division multiple access (MC-CDMA), multicarrier direct sequence CDMA (multicarrier DS-CDMA), and multitone CDMA (MT-CDMA).
2,137 citations
01 Oct 1982
TL;DR: This paper investigates use of a simple robust technique which generates a "quality" bit based on the ratio of the maximum filter output to the second largest filter output, which improves coded system performance by as much as 6 dB for a tone jammer and makes lower redundancy (time diversity) more desirable.
Abstract: It is well known [Refs 1, 2] that a tone or partial-band noise jammer can so choose his jamming strategy as to cause the bit error rate of a frequency-hopped MFSK transmission system, to be an inverse linear function of E b /N o = (W/R)/(J/S), where W is the total available bandwidth available to the communicator, R is the bit rate and J/S is the jammer-to-signal power margin. This situation can be greatly improved by the use of coding, but with hard decisions, performance is still significantly worse than in additive Gaussian noise, unless sufficient time diversity (hops/bit) are employed to thwart such jammers - but at a cost in performance due to coherence loss. This paper investigates use of a simple robust technique which generates a "quality" bit based on the ratio of the maximum filter output to the second largest filter output. This improves coded system performance by as much as 6 dB for a tone jammer and makes lower redundancy (time diversity) more desirable. Performance is determined for both tone and partial band noise jamming and the two are shown to be almost equal and only slightly worse than for full-band Gaussian noise in a coded system.
193 citations
TL;DR: It is shown that the use of ReedSolomon coding with a parallel errors and erasures decoding algorithm accomplishes the goals of providing good performance in partial-band Gaussian noise interference by use of coding and diversity with an efficient error-correction algorithm.
Abstract: This paper is concerned with the performance of a Communications system which utilizes frequency-hop spread spectrum, diversity transmission, Reed-Solomon coding, and parallel error-correction and erasure-correction decoding. Both binary signaling and M -ary orthogonal signaling are considered. The goals are twofold. First, it is desirable to provide good performance in partial-band Gaussian noise interference by use of coding and diversity with an efficient error-correction algorithm. Second, it is necessary to totally neutralize narrow-band interference (regardless of the power level or statistical distribution of the interference) in order to have an effective spread-spectrum system. Through an analysis of the effects of partial-band interference on a frequency-hop spread-spectrum system with diversity, it is shown that the use of ReedSolomon coding with a parallel errors and erasures decoding algorithm accomplishes these goals. The paper also investigates the accuracy of the Chernoff bound as an approximation to the true performance of a frequency-hop spreadspectrum communication system with diversity; side information, M -ary orthogonal signaling, and Reed-Solomon coding. The performance results presented in the paper are based on analysis and computer evaluation. Approximate results based on the Chernoff bound are also given. It is shown that the Chernoff bound for M -ary orthogonal signaling gives a very poor approximation for many cases of interest. This is largely due to the looseness of the union bound.
118 citations