Search results
Results From The WOW.Com Content Network
QAM is used in a variety of communications systems such as Dial-up modems and WiFi. In cable systems, a QAM tuner is linked to the cable in a manner that is equivalent to an ATSC tuner which is required to receive over-the-air (OTA) digital channels broadcast by local television stations when attached to an antenna. Most new HDTV digital ...
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 ...
A number of HD radio tuners have the limited ability to decode C-Quam stereo transmissions, (typically with lower bandwidth), and as a result, reduced audio quality than what could be expected from a specifically designed AMAX/C-QUAM only tuner. C-QUAM AM Stereo transmissions have the same range as AM Monural transmission, a key benefit.
ATSC and DVB-T specify the modulation used for over-the-air digital television; by comparison, QAM is the modulation method used for cable. The specifications for a cable-ready television, then, might state that it supports 8VSB (for broadcast TV) and QAM (for cable TV). 8VSB is an 8-level vestigial sideband modulation.
QAM demodulation requires a coherent receiver. It uses two product detectors whose local reference signals are a quarter cycle apart in phase: one for the in-phase component and one for the quadrature component. The demodulator keeps these product detectors tuned to a continuous or intermittent pilot signal.
A USB digital TV receiver with its antenna. A DTV receiver is a set-top box that permits the reception of digital television.Its components are very similar to a desktop PC. The DTV receiver is a vital link in the chain of television syste
In practice however, the rental of cable converter boxes (or since the late 2010s, the rent-to-own arrangement of digital media players with a provider's app if the customer prefers) has remained a lucrative business line for most cable providers, and they have preferred to phase out support of analog or digital cable-ready televisions which ...
If the carrier signal has only two states, then only one bit of data (i.e., a 0 or 1) can be transmitted in each symbol. The bit rate is in this case equal to the symbol rate. For example, a binary FSK system would allow the carrier to have one of two frequencies, one representing a 0 and the other a 1.