Search results
Results from the WOW.Com Content Network
Many natural and man-made phenomena can disrupt the reception of television signals. These include naturally occurring and artificial spark discharges, and effects due to the operation of radio transmitters. Analog television broadcasts display different effects due to different kinds of interference.
With digital television, because of the cliff effect, reception of the digital signal must be very nearly complete; otherwise, neither audio nor video will be usable. Analog TV began with monophonic sound and later developed multichannel television sound with two independent audio signal channels.
In telecommunications, the (digital) cliff effect or brick-wall effect is a sudden loss of digital signal reception.Unlike analog signals, which gradually fade when signal strength decreases or electromagnetic interference or multipath increases, a digital signal provides data which is either perfect or non-existent at the receiving end.
Digital radio and digital television can also be received; however, there is much greater difficulty with reception of weak signals due to the cliff effect, particularly with the ATSC TV standard mandated in the U.S. However, when the signal is strong enough to be decoded identification is much easier than with analog TV as the picture is ...
A signal sent by an ideal transmitter or received by a receiver would have all constellation points precisely at the ideal locations, however various imperfections in the implementation (such as noise, low image rejection ratio, phase noise, carrier suppression, distortion, etc.) or signal path cause the actual constellation points to deviate ...
Many antennas marketed for digital TV are designed for UHF, which most digital stations use. VHF analog signals travel further than UHF signals, but watchable VHF digital signals appear to have a more limited range than UHF with the lower power they are assigned, and they do not penetrate buildings as well, especially in larger cities.
A simulated example of severe ghosting in an analog TV broadcast. In television, a ghost is a replica of the transmitted image, offset in position, that is superimposed on top of the main image. It is often caused when a TV signal travels by two different paths to a receiving antenna, with a slight difference in timing. [1]
Digital broadcasting standards are only used to broadcast video to viewers; Digital TV stations usually use SDI irrespective of broadcast standard, although it might be possible for a station still using analogue equipment to convert its signal to digital before it is broadcast, or for a station to use digital equipment but convert the signal ...