Multiburst

Abstract: The target damage efficiency is a key content in weapon testing field to assess new weapon damage performance, this paper researches the projectile multiburst location optical testing method based on double area array camera and assessment arithmetic of target damage efficiency. The optical testing model of 3-D coordinate on the projectile multiburst location is set up using double area array camera. Based on the 3-D coordinates of projectile multiburst location and finite element analysis theory, the calculation method of target vulnerability area was researched and analyzed by dividing the target vulnerable area into many unit areas to develop assessment arithmetic of target damage efficiency. The relationship of fragments size, impact angle, and vulnerable surface unit area size and the calculation methods of the target vulnerable area and damage sensitivity were discussed. The target damage probability was also calculated and analyzed using projectile fragments distribution density, number of fragments, and fragment cloud scattering radius. Through the calculation and experiment, the result shows that the assessment of target damage efficiency is closely related to 3-D coordinates of the projectile multiburst location, fragments size and velocity, vulnerable surface unit area size, and effective number of fragments per unit area.

Abstract: The detectability of a sequence of equal-frequency (coherent) tonal components embedded in random, multiburst maskers was evaluated. The masker was comprised of tonal components located in a time-by-frequency spectrogram with eight 30ms time columns and 29 frequency rows ranging logarithmically from 200to5000Hz. The probability that a tone occurred in any one cell of the spectrogram, p, was the independent variable. The signal and masker components were of equal duration and equal level. Using a yes∕no procedure, threshold values of p were estimated for five signal frequencies (220, 445, 1000, 2245, 4490Hz) and when the signal frequency was random. Thresholds were worst for the random-frequency signal and best for the fixed 1000Hz signal. In additional conditions, the value of p was fixed and the signal components were delayed relative to the masker components. A 1ms delay provided better sensitivity (d′ grew from 0.5 to 1) for all but the lowest signal frequency tested. An analysis of no-signal trials re...

Abstract: Although Digital Video Broadcast-Handheld (DVB-H) is currently considered to be a mature technology, new multiburst forward error-correction (FEC) schemes such as multiprotocol encapsulation-interburst FEC (MPE-iFEC) and application-layer FEC (AL-FEC) can be applied to mobile TV streaming services to increase the robustness of the transmission. Compared with the conventional intraburst approach MPE-FEC, multiburst encoding provides protection across several bursts rather than within a single burst because it is possible to recover from completely erroneous bursts. The robustness of the transmission can be enhanced, keeping the capacity devoted for error repair (code rate or FEC overhead) and thus increasing the number of interleaved bursts. This paper describes a methodology for estimating the coverage for multiburst FEC DVB-H mobile TV streaming services in realistic scenarios based on dynamic system-level simulations. Furthermore, it presents illustrative performance-evaluation results with field measurements, and it presents simulation results quantifying the reduction in the fading margin required to cope with fast fading and shadowing that can be achieved with multiburst FEC, compared with MPE-FEC.

Abstract: In this experiment, listeners detected sequential tonal patterns embedded in multitone multiburst random maskers. The maskers consisted of eight 30ms bursts of random-frequency tones. The signal, when present, occupied the central six bursts and was centered at 1000Hz. The six sequential signal tones formed several spectro-temporal patterns: an equal-frequency pattern, three ascending patterns with frequency ranges spanning 0.5-, 1-, and 2-equivalent rectangular bandwidths (ERBs), and a random pattern with frequencies drawn at random from the range of 925–1075Hz. The total number of tones in each burst, m, was varied to determine detection threshold. The detectability of the signal pattern declined as the frequency range of the signal pattern increased, and when the signal was random. Relative weights as a function of time and frequency, interpreted as listeners’ internal templates, depended systematically on the properties of the signal pattern tested. The templates indicated that when sensitivity was po...