Digital Terrestrial TV
Multiplexing is the process of multiplying the number of chains that can be transmitted per carrier frequency.
The carrier frequency can then be similar to a "pipe". This is used to transmit information between the transmitter of a geographical area and the viewer's antenna.
On each carrier frequency will therefore pass audiovisual information relating to each television channel.
Mono or multi-frequency
DTT can be broadcast according to two types of networks. Sfn (Single Freqency Network) or MFN (Multiple Frequency Network) networks.
The networks deployed in analog are mfn type, for this the technical broadcasters prefer this mode;
it allows to reuse the same network layout unlike the SFN. In addition, MFN makes it possible to offer a higher throughput than iso frequency networks.
The main advantage of sfn is to reduce the spectral footprint which is already very large.
In France it was chosen to develop an MFN-type network.
COFDM : Coded Orthogonal Frequency Division Multiplex
QPSK : Quaternary Phase Shift Keying or 4-state phase shift modulation
Qam : Quadrature Amplitude Modulation.