Download or read book Studies of ECCM Improvements for Frequency Hopping CPFSK Systems written by J. S. Lee and published by . This book was released on 1990 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: The performance of frequency-hopping CPFSK modulations (such as used in several Army radio systems) in the presence of worst-case partial-band noise jamming (WCPBNJ) is derived for both limiter-discriminator and differential detector forms of receiver. The transmitter is assumed to repeat the data L times on different hops, and the receiver combines the L chips for each data symbol in a way to mitigate the effects of the jamming. Hard-decision combining simply makes a binary decision on each chip, then a majority decision on the whole symbol; this limits a jammed chip to one vote. AGC combining weights each analog chip sample in inverse proportion to the received noise power and decides on the basis of the sum of weighted chip samples; jammed chips tend to be weighted less. Analysis and computations show that either form of ECM combining can produce a 27 dB gain against WCPBNJ, and with error-control coding, a 31-33 dB gain. Coding alone can give a 28-29 dB gain. Soft decoding of hard-decision diversity combining gives 1.4 dB more gain than hard decoding. It is also shown that, due to the spectral attenuation characteristics of the receiver's IF filter, the effects of the transient phase difference between the incoming hopping waveform and the receiver's synthesizer are primarily confined to an interval of duration T + ts + tau, where T is the symbol duration (inverse of IF bandwidth), ts is the synthesizer switching time, and tau is the offset in synchronization between the received signal and the receiver's synthesizer. (rh).

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1990 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Diversity ECCM Performance of Frequency Hopping CPFSK in Partial Band Noise Jamming written by L. E. Miller and published by . This book was released on 1988 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: A thorough analysis is made of the uncoded probability of error achieved by by a hopped CPFSK (narrowband digital FM) radio link while subject to partial band noise jamming. Included in the analysis are the effects of thermal noise, FM clicks, and intersymbol interference, in addition to the jamming. For both limiter-discriminator and differential detection, it is shown that a repeat diversity combining method of summing detector samples does not yield a diversity gain against worst-case partial-band noise jamming, despite the nonlinearity of the receiver. The analytical procedures formulated, and computer programs, developed, can be modified to treat other CPFSK combining metrics; it is recommended that other soft-decision metrics be evaluated for ECCM properties, since it is known that at diversity gain is theoretically possible using perfect side information. In the report, easily calculated approximations and short-cut expressions for the error probability are assessed for accuracy, using the more complicated exact formulas. Keywords: Frequency shift keyers; Continuous phase, Frequency hopping, Digital FM radio, ECCM, jamming, Statistical communication theory; Phase distributions. (JD/RH).

Download or read book Research in Progress written by and published by . This book was released on 1982 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Government Reports Annual Index written by and published by . This book was released on 1990 with total page 1604 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Communications fusing Command Control and Intelligence written by and published by . This book was released on 1992 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book IEEE International Symposium on Information Theory 1993 written by IEEE Information Theory Society and published by Institute of Electrical & Electronics Engineers(IEEE). This book was released on 1993 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book IEEE International Symposium on Information Theory written by and published by . This book was released on 1992 with total page 474 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Applications of Frequency Hopping Systems written by Chen Jiang and published by . This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Frequency Hopping Multiple Frequency Shift Keying Coding and Optimal Partial Band Jamming written by Don J. Torrieri and published by . This book was released on 1982 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: The performance of frequency-hopping systems with multiple frequency-shift keying is determined for operation against optimal partial-band jamming. The effects of Reed-Solomon, binary block, convolutional, and concatenated codes are analyzed. Continuous-phase frequency-shift keying with limiter-discriminato demodulation is shown to offer potentially improved performance in frequency-hopping systems. (Author).

Download or read book Government Reports Announcements Index written by and published by . This book was released on 1990 with total page 990 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proceedings IEEE International Symposium on Information Theory written by and published by . This book was released on 1992 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Code shift Keying for Frequency hopping HF Systems with Multipath Propagation written by G. O. Venier and published by . This book was released on 1991 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Conference Record written by and published by . This book was released on 1985 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book International Aerospace Abstracts written by and published by . This book was released on 1990 with total page 944 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Communications computers Teamed for the 90 s written by and published by . This book was released on 1986 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dictionary of Acronyms and Technical Abbreviations written by Jakob Vlietstra and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 703 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Dictionary covers information and communication technology (ICT), including hardware and software; information networks, including the Internet and the World Wide Web; automatic control; and ICT-related computer-aided fields. The Dictionary also lists abbreviated names of relevant organizations, conferences, symposia and workshops. This reference is important for all practitioners and users in the areas mentioned above, and those who consult or write technical material. This Second Edition contains 10,000 new entries, for a total of 33,000.