Patent ID: 8565346

Claim:
An apparatus for generating and transmitting a frame in a wireless communication system, the apparatus comprising: a frame generator configured to generate a frame comprising: a short preamble comprising a symbol for timing synchronization, first and second long preambles subsequent to the short preamble, a data field subsequent to the first and second long preambles, wherein the second long preamble provides reference for a receiving apparatus to form a channel estimate that allows the receiving apparatus to demodulate the data field, and a signal symbol between the first long preamble and the second long preamble, wherein the signal symbol comprises information about coding rate, modulation, and space time block coding; and a transmitter configured to transmit the frame to the receiving apparatus, wherein the first long preamble is preceded by a guard interval having a length of 1.6 μsec, the second long preamble includes two long preambles T 1 , T 2 wherein each of the two long preambles T 1 , T 2 is respectively preceded by a guard interval having a length of 0.8 μsec, and the data field is preceded by a guard interval having a length of 0.8 μsec.