Abstract: An method and apparatus for transmitting ranging information from at least one base station to subscriber stations and generating a ranging signal by the subscriber station using received ranging information in a Broadband Wireless Access (BWA) communication system including a plurality of neighbor cells and a plurality of the subscriber stations located in each cell region. A first code generator generates a first code using different first code information received from the base stations in the neighbor cells allocated the first code information. A second code generator generates a second code using second code information received by each of the subscriber stations existing in cell regions of the neighbor cells. A ranging signal generator generates a new ranging signal by combining the first code with the second code.

Abstract: A two-dimensional subchannel assigning method and apparatus in a time-frequency domain where a plurality of subcarriers are arranged along a time domain with a plurality of symbols and along a frequency domain with a plurality of subbands in an OFDM communication system. In the subchannel assigning method, the plurality of subcarriers are divided into a plurality of frequency bands and the frequency bands are grouped into the subbands. A plurality of groups are generated by dividing each of the subbands in the frequency domain by the number of the symbols in the time domain. Subcarriers selected from the respective groups in each of the subbands are assigned as an AMC subchannel to which an AMC scheme is applied.

Abstract: A wireless communication system that divides an entire frequency band into a plurality of subcarrier bands and includes a plurality of subchannels, each of which is a set of a predetermined number of subcarrier bands. As many subcarrier groups as the number of the base stations are generated by classifying the subcarrier bands in a predetermined period. For a particular base station, corresponding subcarrier bands are detected from each of the groups according to a predetermined sequence. The subcarrier bands detected from each of the groups are assigned as a subchannel for the particular base station.