Patent ID: 7072419
Filing Date: 2006-07-04
Classification: H04L

Abstract:
1. A data communication apparatus based on orthogonal frequency division multiple access (OFDMA) comprising a base station transmitting unit which transmits user information for at least one user, the base station transmitting unit comprising: first through U-th encoders among which a u-th encoder (where 1≦u≦U, and U indicates the number of users) encodes the user information and outputs the result of encoding as N a frequency allocator for allocating different frequencies to the user symbols received from each of the first through U-th encoders and outputting the results of allocation; a first inverse Fourier transformer for performing N-point inverse Fourier transform on the results of allocation received from the frequency allocator (where N is a total number of symbols which can be allocated to the U users); a first cyclic extension symbol inserter for inserting a cyclic extension symbol into the result of inverse Fourier transform; and a first signal transmitter for converting the result of insertion into a symbol block signal and transmitting the symbol block signal to the user, wherein the sum of N