Study of tropospheric scintillation effects in Ku-band frequency for satellite communication system

Scintillation is a rapid fluctuation of an electromagnetic waves in terms of phase and amplitude due to a small-scale inconsistency in the transmission path (or paths) with time. Scintillation exists continuously throughout a day whether during raining or clear sky conditions. The raw signal data need to exclude other propagations factors that include signal fluctuations to further understand the scintillation studies. This paper presents the analysis of tropospheric scintillation data from January 2016 till December 2016 at Ku-band frequency of 12.202 GHz beacon signal. The experimental data from MEASAT 3B were collected and analyzed to see the effect of tropospheric scintillation. The elevation angle of the dish antenna is 77.45o. The highlighted objectives are to analyze the scintillation data at Ku-band, and to compare and validate the results with other scintillation models. The result shows that the stipulated scintillation analysis has higher amplitude, which is 0.73 dB compared to other scintillation analysis which has lower scintillation amplitude: 0.45 dB (Karasawa), 0.42 dB (ITU-R), 0.4 dB (Nadirah & Rafiqul), 0.42 dB (Van De Kamp) and 0.11 dB (Anthony & Mandeep).

A Novel Underwater Location Beacon Signal Detection Method Based on Mixing and Normalizing Stochastic Resonance

A flight data recorder (FDR) is an electronic recording device placed in an aircraft for the purpose of facilitating the investigation of aviation accidents. If an aircraft crashes into water, an underwater locator beacon (ULB), which is installed on the FDR, is triggered by water immersion, and emits an ultrasonic 10 ms pulse signal once per second at 37.5 kHz. This pulse signal can be detected by sonar equipment. However, the ULB signal only can be detectable 1–2 kilometers from the surface in normal conditions. Stochastic resonance (SR) is a rising theory in the field of weak signal detection. The classical stochastic resonance limits state that the input must be small-parameter and the sampling frequency must be 50 times higher than the signal frequency. It cannot be applied to the ULB signal detection. To resolve this problem, this paper presents a novel approach named mixing and normalizing stochastic resonance (MNSR). By mixing the ULB signal and normalizing SR system parameters, MNSR provides a new way to detect weak ULB signal. Meanwhile, we propose the parameters adjustment method of MNSR. We prove the effectiveness through numerical simulation. An experiment in a tank is employed to verify the practicability of this method.

Cognitive Radio Networks

Cognitive radio (CR) offers a novel way for effective usage of wireless spectrum by using dynamic spectrum sensing and allocation. One of the main components of CR is to find a spectrum hole for data transmission. Spectrum hole can be found by using spectrum sensing, a geolocation database, or by using a beacon signal. In this chapter, the authors describe algorithms for spectrum sensing in the presence of both additive white Gaussian and colored Gaussian noise. The algorithms include blind, non-blind, and cooperative sensing-based methods. The authors have compared the performance of various methods for IEEE 802.22 standard (which is the first standard incorporating CR).

PERFORMANCE ANALYSIS OF SISPELSAT MSK-DGNSS RADIO SIGNAL IN PENINSULAR MALAYSIA

<p><strong>Abstract.</strong> The use of Global Navigation Satellite System (GNSS) has become essential in providing location based information and navigation. Due to low accuracy of navigation solution, differential technique such as radio-beacon DGNSS has been used widely to augment the user single positioning using GPS. The <i>Sistem Pelayaran Satelit</i> (SISPELSAT) is a national DGNSS radio-beacon system in Malaysia consists of four broadcasting and two monitoring stations operated and managed by Marine Department of Malaysia. It provides a range of frequency from 283.5 to 325<span class="thinspace"></span>kHz Minimum Shift Keying (MSK) radio-beacon DGNSS correction service within the shore of Peninsular Malaysia. In this study, the performance of SISPELSAT radio signal was assessed on-board of the Malaysian Vessel (MV) Pedoman and MV Pendamar. The study area covers 20<span class="thinspace"></span>km shore distance extending from shoreline of Peninsular Malaysia with continuous tracking from SISPELSAT radio beacon signal. The DGPS observation data as well as the coverage of the signal strength, signal-to-noise ratio, accuracy and DGPS status were recorded for data processing and further analysis of SISPELSAT radio signal performance.</p>