1,721,355 research outputs found
The Record-Setting Marconian Radio Station in Coltano, Italy
No full textIn September, 1902, Marconi was back from a long trip on the Italian Royal Navy's cruiser "Carlo Alberto", where he successfully carried out many radio experiments in the northern seas, and soon, he expressed his intention to build a powerful intercontinental station in Italy. The station, which would be the first in Marconi's home country (and one of the first in the world, too), was intended to provide radiotelegraphic connections with Americas and Africa using frequencies below 100 kHz, which, at the time, were believed to be the sole option for long-distance radio communications. After some surveys across Italy, the selected site for this new station was Coltano, a marshy rural area between Pisa and Leghorn, near the Tyrrhenian Sea. The station was then inaugurated by Marconi itself in 1911 with transmissions to Clifden (Ireland) and Glace Bay (Canada), followed by a pioneeristic link reaching Massawa (Eritrea), across more than 2000 km of Sahara's dry soil, which, until then, was considered an unsurmountable obstacle for the propagation of low-frequency ground waves. This was just one of many astonishing records set by this once worldwide renowned, but now almost completely forgotten, radio station, born from Marconi's genius
Coltano: the Forgotten Story of Marconi's Early Powerful Station
Full text linkOn September 8, 1902, at the dawn of the wireless telegraphy age, Marconi was looking at the Tuscan coast from the cruiser “Carlo Alberto,” back from a long trip where he successfully carried out many radio experiments in the northern seas. While passing in front of Leghorn, Marconi expressed to the Admiral Mirabello his intention to build a powerful intercontinental station in the plain behind that city. The station, which would be the first in Marconi's home country (and one of the first in the world, too), was intended to provide radiotelegraphic connections with Africa and America in the very low-frequency (VLF) band, i.e., using carrier frequencies below 100 kHz, which, at the time, were believed to be the sole option for long-distance radio communications
Digital Satellite Receiver for Wideband Multi-Rate Ka-Band Communications
No full textThis correspondence presents the architecture of a high-speed low-complexity digital receiver for wideband satellite communications supporting multiple baud rates, ranging from 10 to 200 MBaud. The design of the modem is based on the Cascaded Integrator-Comb (CIC) scheme which exploits a parallel processing so as to provide an outstanding decimation agility. Eventually, bit error rate (BER) performance of the multi-rate receiver are assessed by floating-point simulations
Multi-Rate Modem Front-End for High Speed Satellite Data Transmission
No full textModern communication terminals for wireless communications are based on an all-digital architecture wherein the incoming signal undergoes analog-to-digital conversion (ADC) at intermediate frequency (IF) followed by full-digital frequency down-conversion. Moreover, baseband digital signal processing is typically carried out at 2 samples per symbol so that the high-rate digital stream at the ADC output must be decimated down to twice the symbol rate. This paper describes the architecture of a modem for satellite communications featuring a decimating front-end. Particular emphasis is devoted to the adoption of parallel-processing solutions to overcome the inherent speed limitation of a conventional serial architecture, dictated by the technology of the digital devices. We devise herein a decimator architecture yielding a parallelization by a factor of two while bearing the same implementation complexity as the conventional schemes. Analysis and simulation of the parallelized receiver architecture with multi-level turbo-coded signal exhibit a negligible loss due to the digital front end with respect to “ideal” down-conversion and decimation
Very High Speed and Low Complexity Digital Front-End of a Wideband Multirate Satellite Ka-band Receiver
No full textRadio Design Criteria in the Early XX Century: The Dawn of the Global Communication Era
No full textThe early years of the XX century witnessed a series of milestone achievements in long-range wireless communications that paved the way for the activation of the first intercontinental radiotelegraphic commercial service in 1907, a fundamental step toward the development of the modern global radio communication network. This work illustrates the state-of-the-art in radio technology at that time and the relevant design criteria
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