Digial Modulation Technique

There are three predominant methods of encoding a transmission signal. Amplitude modulation (AM), and frequency modulation (FM) are both analog modulation schemes. The third method is digital modulation.

In Digital modulation followings are involved. They are,

• QPSK( Quadrature Phase Shift Keying )DVB-S
• QAM( Qudrature Amplitude Modulation )CABLE
• COFDM( Coded Orthogonal Frequency Division Mulitiplexing )DVB-T

Standards Otherthan DVB

1. ATSC

The Advanced Television Systems Committee (ATSC) is the group that helped to develop the new digital television standard for the United States, also adopted by Canada, Mexico, and South Korea and being considered by other countries.It is intended to replace the NTSC system and produce wide screen 16:9 images up to 1920×1080 pixels in size. More than six times the display resolution of the earlier standard.

2. ISDB

Integrated Services Digital Broadcasting (ISDB) is the digital television (DTV) and digital audio broadcasting (DAB) format that Japan has created to allow radio and television stations there to convert to digital.

3. ARIB

The Association of Radio Industries and Businesses, commonly known as ARIB, is a standardization organization in Japan. ARIB is designated as the center of promotion of the efficient use of the radio spectrum and designated frequency change support agency.

4. SBTVD

Brazilian Digital Television System is a proposed digital television standard for Brazil.