Intersymbol interference is a signal distortion in telecommunication. One or more symbols can interfere with other symbols causing noise or a less reliable signal. The main causes of intersymbol interference are multipath propagation or non-linear frequency in channels. This has the effect of a blur or mixture of symbols, which can reduce signal clarity. If …
Pulse Amplitude Modulation (PAM) is the simplest form of pulse modulation. This technique transmits data by varying the voltage or power amplitudes of individual pulses in a timed sequence of electromagnetic pulses. In other words, the data to be transmitted is encoded in the amplitude of a series of signal pulses. PAM can also be …
An inductor is a conducting coil, wrapped around a core, that creates inductance when an alternating current flows through it. Inductors are used to impede the flow of current in a circuit. The conductor is usually thin magnet wire, and the core is usually air or steel. Working of an Inductor When the alternating current …
A ground loop isolator prevents interference in a ground loop circuit. A ground loop circuit is one in which two or more circuits are connected to the same ground wire. Ideally, all circuits in a ground loop circuit have the same voltage potential. However, if the ground wire has significant resistance and current, the voltage …
Pulse Code Modulation (PCM) was pioneered by the British engineer Alec Reeves in 1937. The first transmission of a message using PCM was the SIGSALY voice encryption equipment used in high-level Allied communications during World War II starting in 1943. The original primary application for PCM was to convert analog signals into digital format by …
Satellite images are taken by reconnaissance satellites that orbit the Earth at a relatively low altitude, between 300 to 600 miles (or 480 to 970 km). As the majority of today's satellites are custom made in order to accommodate particular needs of the designer, there is no standard on which photo imagery is based on …
An alternator turns mechanical energy into electrical energy, in the form of alternating current. It is a type of generator, most commonly used by automobiles to power their electrical systems. They are usually mounted on the side of the internal combustion engine. How Alternators Work An alternator consists of a rotor, stator, rectifier, housing, and …
A loop antenna is one that is designed to receive radio signals more efficiently than other antennas. Loop antennas are considered more efficient than others because they are mobile, work with a wide range of frequencies, and use less electricity. A loop antenna’s performance is entirely dependent on its construction and placement, although other factors …
ODU (Out-Door Unit) refers to the set of satellite equipment which is placed outside of the building. The ODU typically includes a satellite dish, a feedhorn, and a LNB (Low Noise Block). In bi-directional satellite systems, the ODU will also include a BUC (Block Up Convertor). The ODU is connected to the IDU (In-Door-Unit) by …
S band is a frequency range from approximately 2 to 4 GHz. S band is used for Digital Audio Radio Satellite (DARS) satellite radio systems such as Sirius XM Satellite Radio. Sirius XM uses frequencies between 2,320.00 and 2,332.50 MHz, and also between 2,332.50 and 2,345.00 MHz. S band is also used by many weather, …