What does COFDM stand for?
COFDM stands for coded orthogonal frequency domain multiplex and is a digital coding scheme for carrying up to 6875 single carriers 1 kHz apart which are QAM modulated with up to 64 states. "Coded" means that the data to be modulated has error control. Orthogonality means that the spectra of the individual carriers do not influence each other as a spectral maximum always coincides with a spectrum zero of the adjacent carriers. A single-frequency network is used for the actual transmission. This is a modulation scheme used for digital transmission that is employed by the European DVB system. It uses a very large number of carriers (hundreds or thousands), each carrying data at a very low rate. The system is relatively insensitive to doppler frequency shifts, and can use multipath signals constructively. It is, therefore, particularly suited for mobile reception and for single-frequency networks. It is a modified form of OFDM.
常見問答集 ID 53171檢視所有常見問答集 »