Abstract: The present invention discloses a preamble sequence generating method and device, which are used to avoid a problem, caused by damages to a preamble sequence resulting from interference in an NB-PLC system, that it is difficult for a receive end to correctly perform timing synchronization. The method includes: determining a quantity m of orthogonal frequency division multiplexing OFDM symbols that constitute a single pattern in a preamble sequence, where m is not less than 2; and generating a preamble sequence according to m, so that every m OFDM symbols that are in the generated preamble sequence and consecutive in a time domain constitute a single pattern, and the generated preamble sequence includes at least two patterns, where the patterns are different from each other. Embodiments of the present invention further provide a timing synchronization method and device.

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 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.