Abstract: A method for transmitting scattered pilot signals in a multi-carrier system is disclosed. The method includes: in each time slot, in time dimension, putting each 4 OFDM symbols into a group according to the order of the OFDM symbols; in each group of OFDM symbols, in frequency dimension, selecting, for each OFDM symbol, a plurality of valid sub-carriers to transmit scattered pilots, wherein for a same OFDM symbol, between each 2 valid sub-carriers selected, there are 7 valid sub-carriers; for different OFDM symbols in a same group, the valid sub-carriers selected are interleaving in frequency domain; and transmitting scattered pilot signals on the valid sub-carriers selected. The solution helps the multi-carrier system to handle multi-path channel with large delay spread, to obtain more accurate channel estimation and to achieve better receiving performance.

Abstract: A method, transmitter and modulator for signal synchronization transmission in a single frequency network transmission system are disclosed. The method includes: extracting effective data from data received; performing channel coding, mapping and modulation to the effective data extracted and saving the data modulated into storage; and retrieving the data from the storage upon receiving a pulse indication signal, performing digital-to-analog conversion and baseband-to-radio frequency conversion to the data retrieved and transmitting the data converted into air via antennae. The technical scheme enables different transmitters to transmit signals synchronously.

Abstract: The invention discloses a signal transmission system, method and apparatus, and relates to the fields of communications and broadcast television. It is intended to reduce the hardware cost of the signal transmitting system. The system according to the invention is based on a personal computer operating system, and comprises a computer and a transmitting equipment, said computer comprising a signal source processing module for processing a signal source, a channel encoding and modulating module for channel encoding and modulating of the processed signal source, and an interface module for outputting the data encoded and modulated by the channel encoding and modulating module, and said transmitting equipment being arranged to receive data from the interface module, process the received data into a radio frequency RF signal, and then transmit the RF signal. The invention may be applicable to a transmitter of broadcast television.