Military Communications Conference, 1989. MILCOM '89. Conference Record. Bridging the Gap. Interoperability, Survivability, Security., 1989 IEEE

15-18 Oct. 1989

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  • Adaptive HF for voice and data

    Publication Year: 1989
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (42 KB)

    Summary form only given. The authors describe an adaptive HF system for voice and video. The system uses information obtained from a link quality analysis and/or ionospheric soundings to determine the appropriate link and frequency over which to communicate. In addition, the system can be frequency hopped, thereby reducing the probability of being jammed. The improved performance obtained using fr... View full abstract»

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  • MILCOM 89. Bridging the Gap. Interoperability, Survivability, Security. Conference Record. 1989 IEEE Military Communications Conference (Cat. No.89CH2681-5)

    Publication Year: 1989
    Request permission for commercial reuse | PDF file iconPDF (157 KB)
    Freely Available from IEEE
  • Nonbinary forward error correction for military communications

    Publication Year: 1989, Page(s):200 - 204 vol.1
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (304 KB)

    The authors present an alternative nonbinary coding scheme that is an extension of a previously developed binary code, called the yjr projection code. The projection code is characterized by simple implementation and high speed, making it attractive for low-cost error-control systems. Projection codes are capable of efficiently correcting both random and burst errors and are well suited to ARQ ope... View full abstract»

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  • Trellis coding for high signal-to-noise ratio Gaussian noise channels

    Publication Year: 1989, Page(s):196 - 199 vol.1
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (256 KB)

    It is known that under energy constraints it is best to have each code word of a code satisfy the constraint with equality, rather than have the constraint satisfied only in an average sense over all code words. This suggests the use of fixed-composition codes on additive Gaussian noise channels, for which the coding gains achievable by this method are significant, especially in the high signal-to... View full abstract»

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  • A robust adaptive filtering algorithm with variable step size

    Publication Year: 1989, Page(s):526 - 530 vol.2
    Cited by:  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (244 KB)

    The authors present a variable-step adaptive filtering algorithm (VS-NLMS) that is robust in the presence of interference. An estimated cross-correlation coefficient between the input reference signal and the error signal is used as the variable step size. Compared with the conventional fixed-step adaptive filtering algorithm (NLMS), the VS-NLMS algorithm can achieve much lower misadjustment noise... View full abstract»

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  • Performance of error-erasure-correction decoding of Reed-Solomon codes for frequency-loop communications in multitone jamming

    Publication Year: 1989, Page(s):189 - 195 vol.1
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (480 KB)

    The performance of a recently proposed efficient antijam communication system is examined. The system employs frequency-hopping (FH), MFSK, (M-ary frequency-shift-keying) modulation, diversity, Reed-Solomon (RS) coding, and parallel error-erasure-correction decoding. The performance of the system in multitone (MT) jamming is evaluated by use of an exact method rather than a bounding techn... View full abstract»

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  • An adaptive clutter and interference suppression with a minimum residue noise power

    Publication Year: 1989, Page(s):521 - 525 vol.2
    Cited by:  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (380 KB)

    The author presents an adaptive technique for the suppression of clutter and interference in environments where no a priori knowledge about the target or the clutter and interference statistics is available. The adaptive processor generates the average weight vector, in the sense of minimum-residue-noise-power, on the basis of the injected noise-level vector in the weight control algorithm. The se... View full abstract»

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  • MACSIM: an event driven simulation of an HF radio network

    Publication Year: 1989, Page(s):95 - 99 vol.1
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (484 KB)

    The authors describe MACSIM, a computer simulation developed to aid in the design and analysis of HF radio networks. They discuss MACSIM's application to the network design process and provide the results of several stages of analysis, where MACSIM was used to evaluate preliminary network designs. MACSIM provides an effective and flexible tool for defining network structures, developing routing an... View full abstract»

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  • Performance of BCH and convolutional codes in direct sequence spread spectrum packet radio networks

    Publication Year: 1989, Page(s):184 - 188 vol.1
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (264 KB)

    The authors examine the performance of BCH and convolutional codes in a direct-sequence spread-spectrum packet radio network. Packet errors are caused by a combination of noise at the receiver and interference between packet transmissions that overlap in time. The interference between packet transmissions produces dependent symbol errors at the output of the demodulator. The authors first compute ... View full abstract»

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  • Adaptive interference rejection in a digital direct sequence spread spectrum receiver

    Publication Year: 1989, Page(s):514 - 520 vol.2
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (444 KB)

    To improve system performance in the presence of continuous-wave (CW) interference, a 2-b analog-to-digital converter (ADC) with adaptive thresholds has been implemented in a DSSS (direct-sequence spread-spectrum) receiver for code-shift-keyed signals. The theoretical and measured system performance of a hard limiter and the adaptive 2-bit ADC to accomplish analog-to-digital (A/D) conversion in th... View full abstract»

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  • A technique for detecting unknown weak signals in noise that is not additive white Gaussian

    Publication Year: 1989, Page(s):370 - 376 vol.2
    Cited by:  Papers (12)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (376 KB)

    A general spectrum-analysis-based approach to the problem of detecting the presence of unknown weak signals in noisy observations is developed. The weak signal assumption enables exploitation of familiar results from the theory of local optimality, from which correlation-based detectors for the presence of known weak signals in additive independent and identically distributed (IID) noise have been... View full abstract»

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  • Energy detector performance in a noise fluctuating channel

    Publication Year: 1989, Page(s):85 - 89 vol.1
    Cited by:  Papers (15)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (348 KB)

    The authors address the energy detection performance of a detector, or more specifically, the determination of the required signal-to-noise ratio (Ps/Pn) for given probabilities of detection (Pd) and probabilities of false-alarm (Pfa) in a noise fluctuating channel. A theoretical model for evaluating energy detection p... View full abstract»

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  • Error correcting unit for slow frequency hopping radio stations

    Publication Year: 1989, Page(s):179 - 183 vol.1
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (388 KB)

    The design, features, and implementation of an error-correcting unit (codec) for combat net radio systems are described. Extensive measurements have been made on the developed unit, and it has shown very good error-correcting capabilities. Bit-error rates and block-error rates have been measured for different jamming situations. Measurements have been made for user rates of 2400, 1200, 600, and 30... View full abstract»

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  • Performance analysis of meteor burst communication networks

    Publication Year: 1989, Page(s):408 - 412 vol.2
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (344 KB)

    A Monte Carlo simulation (METEORNET) has been developed to analyze the performance of meteor burst networks. The program employs usable rate and duty cycle statistics derived from the METLINK computer model to predict the waiting time for message reception between nodes in a distributed network. METEORNET is useful in performing trade studies to optimize link performance with respect to the networ... View full abstract»

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  • On air defense communications network connectivity

    Publication Year: 1989, Page(s):677 - 681 vol.3
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (308 KB)

    The authors address the issue of communication network survivability and provide a quantitative measure of the time-varying connectivity of space and ground multimedia networks operating in stressed environments. This measure allows comparison of very different network architectures in terms of connectivity. A generic SBR (Space-Based Radar) constellation was selected for study of the communicatio... View full abstract»

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  • Narrowband interference suppression in a spread-spectrum system using vector space methods

    Publication Year: 1989, Page(s):508 - 513 vol.2
    Cited by:  Papers (5)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (396 KB)

    The author develops vector-space interference-excision (VSIE) methods that suppress the sidelobes of a sine-wave interferer, in addition to the central lobe, while removing little signal power. THE (threshold excision) and VSIE are applied to synthetic data sets consisting of a binary PN (pseudonoise) sequence in Gaussian background noise and sine-wave interference. Signal-to-noise ratios (SNRs) a... View full abstract»

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  • Limitations on the detectability of spread-spectrum signals

    Publication Year: 1989, Page(s):364 - 369 vol.2
    Cited by:  Papers (2)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (348 KB)

    The standard analysis of the radiometric detectability of a spread-spectrum signal assumes a background of stationary white Gaussian noise whose power spectral density can be measured very accurately. This assumption yields a fairly high probability of interception, even for signals of short duration. Using a generalization of the detection scenario, the authors demonstrate that realistic detectio... View full abstract»

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  • An in-band frequency agility modem implemented with a DSP device

    Publication Year: 1989, Page(s):80 - 84 vol.1
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (256 KB)

    The authors present a modem with in-band frequency agility that has been implemented with the TMS 32010 signal processor. A strategy based on embedded real-time channel estimation (RTCE) has been adopted to manage the frequency agility. This strategy has the advantage of being able to combat frequency-selective interferences, and it involves low handling complexity. The authors present measurement... View full abstract»

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  • Wideband HF noise and interference modeling

    Publication Year: 1989, Page(s):846 - 851 vol.3
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (332 KB)

    Previously proposed noise and interference models are briefly reviewed, and the limitations of these models are discussed. A simple one-parameter model of noise and interference over wideband HF channels is then presented. An expression for the APD (amplitude probability distribution) of the model is derived. The underlying assumptions of the proposed model are discussed, and a simple model of spe... View full abstract»

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  • Stanford Telecom VLSI design of a convolutional decoder

    Publication Year: 1989, Page(s):171 - 178 vol.1
    Cited by:  Papers (17)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (532 KB)

    The authors describe the novel hardware and speed-efficient architectural features of a recent Stanford Telecom VLSI implementation of a 20-Mb/s convolutional decoder using 1.5-μm CMOS technology. The chip offers a selection of convolutional codes, including the (2,1) K=7 code commonly used in satellite communications, high-rate punctured versions of the code, and a (2,1) K=6 ... View full abstract»

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  • Diversity reservation ALOHA

    Publication Year: 1989, Page(s):402 - 407 vol.2
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (524 KB)

    A multiaccess protocol suitable for packet-switched satellite broadcast channels is considered. The proposed protocol, called diversity reservation ALOHA (DRA), combines the essential features of announced retransmission random access (ARRA), reservation ALOHA, and diversity ALOHA to achieve the goals of improved delay-throughput characteristics and high channel utilization. Two versions of DRA pr... View full abstract»

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  • A class of adaptive routing and link assignment algorithms for large-scale networks with dynamic topology

    Publication Year: 1989, Page(s):671 - 676 vol.3
    Cited by:  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (456 KB)

    The authors present novel algorithms for adaptive routing and link assignment, which can be used in a large-scale network (1000-10000 nodes) with dynamic topology and stress. Special attention was given to performance (delay, throughput, and survivability) and implementation cost issues as the size of the network grows. These costs are controlled by a logical partitioning of the network into areas... View full abstract»

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  • Adaptive interference rejection for wide-band systems

    Publication Year: 1989, Page(s):503 - 507 vol.2
    Cited by:  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (352 KB)

    The authors describe the RAC (reflective array compressor) exciser, an adaptive band-reject or notch filter based on the multiply-convole chirp-Z transform algorithm. This system uses RAC, which are surface-acoustic-wave dispersive delay lines, in a preprocessor for rejection of overpowering interferers in wideband signal-processing systems. The exciser has been successful in adaptively r... View full abstract»

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  • Utility analysis of fiber optic networks in MILSATCOM architecture

    Publication Year: 1989, Page(s):251 - 257 vol.1
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (456 KB)

    The author presents an analysis of the capacity demand and availability projections of worldwide transoceanic and terrestrial fiber-optic systems. The excess capacity can be used to support a new tactical architectural concept developed here. The fiber-optic and satellite dual-service provisions at major military gateways where there are fiber cable facilities available would allow off-loading MIL... View full abstract»

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  • Comparison of symbol-rate detector and radiometer intercept receiver performances in a nonstationary environment

    Publication Year: 1989, Page(s):359 - 363 vol.2
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (364 KB)

    The performances of radiometer and DMR (delay and multiply receiver) intercept receivers have been compared. Examples showing the detectability of direct sequence spread spectrum versus spreading ratio and noise fluctuation are given. Comparisons are also made between communicator performance and interceptor performance. It is shown that the DMR can give superior performance in an environment with... View full abstract»

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