Patent ID: 7417946

Claim:
An orthogonal frequency division multiplexing (OFDM) transmission apparatus having minimal transmission delay, the apparatus having a scrambler, a convolution encoder, an interleaver, a constellation mapper, an inverse fast Fourier transformer, a guard-interval inserter, a symbol wave-shaping filter and a Radio Frequency (RF) converter, and transmitting a frame composed of a preamble, a signal field and a data field that are received from a Media Access Control (MAC) layer, that is, an upper layer, comprising: a training symbol storage and generation unit for storing training symbols for the preamble, and outputting the stored training symbols when a training symbol output request signal is received; a delay unit for receiving data for the signal field from the MAC layer, delaying the received data by data processing time of the scrambler, and then outputting the delayed data to the convolution encoder; and a controller for outputting the training symbol output request signal, requesting the preamble of the frame, to the training symbol storage and generation unit when a frame transmission request is received from the MAC layer, and outputting a data request signal, requesting the signal field and the data field, to the MAC layer in consideration of total data processing time (T PROCESS ) required by components ranging from the scrambler to the guard-interval inserter; wherein the scrambler scrambles the received data for the data field of the transmitted frame, and then transmits the scrambled data to the convolution encoder.