Radio transmitting apparatus and radio transmitting method

摘要

A radio transmitting apparatus and a radio transmitting method wherein the interference between codes can be reduced and the degradation of preamble detection capability can be prevented. According to these apparatus and method, a signature table storing part (103) that stores a table including a plurality of signatures obtained by classifying the magnitudes of propagation loss levels into levels in accordance with the distances from a base station, associating preamble detection window widths with those levels as classified, and by circularly shifting the pattern of a detection window signature #n corresponding to a signature #n to generate a signature #n+1. A signature selecting part (104) selects, based on the magnitude of a propagation loss level outputted by a propagation loss level determining part (102), one of the corresponding signatures from the signature table storing part (103) at random. A RACH signal generating part (105) uses the selected signature to generate a RACH signal.