Transmit diversity method applied to a transmitting system and transmitting system having multi-transmission paths thereof

A transmitting system having multi-transmission paths, comprising:

• a serial-to-parallel transform circuit, for receiving a serial stream, and for transforming the serial stream into a plurality of parallel streams, wherein each parallel stream is carried by a corresponding sub-carrier;
• at least two transmission paths, wherein each of the at least two transmission paths has a channel coefficient;
• and
• a transmission path selector, coupled between the serial-to-parallel transform circuit and the at least two transmission paths;
• wherein in light of each sub-carrier, the transmission path selector selects a single transmission path from the at least two transmission paths of the transmitting system by comparing energies of a plurality of channel coefficients corresponding to the at least two transmission paths on the sub-carrier, so as to transmit the parallel stream carried by the sub-carrier;
• wherein the each channel coefficient is defined by y=h*s+N, where y is a receiving signal of the sub-carrier on the corresponding transmission path, h is the channel coefficient, s is a transmitting signal of the sub-carrier, and N is noise.