RADIO COMMUNICATION SYSTEM AND TRANSMISSION MODE SELECTING METHOD

摘要

A radio communication system for quickly selecting an optimum transmission mode in accordance with the quality and condition of a propagation path. The radio communication system has first and second radio apparatuses capable of radio-communicating with each other. The first radio apparatus (2) comprises a propagation path environment estimation part (208) for estimating, from a signal outputted from the second radio apparatus (1), the propagation path environment between the first and second radio apparatuses and then outputting the estimation result as propagation path environment information; a propagation path quality estimation part (209) for estimating, from the signal outputted from the second radio apparatus (1), a propagation path quality between the first and second radio apparatuses and then outputting the estimation result as propagation path quality information; and a transmission part (211) for transmitting the propagation path environment information and propagation path quality information as well as data signals to the second radio apparatus (1). The second radio apparatus (1) comprises a transmission mode selecting part (16) for selecting, in accordance with the propagation path environment information, one of a plurality of tables in which a plurality of transmission modes having thresholds associated with the values of the propagation path environment information have been registered, and then selecting, in accordance with the propagation path quality information, one of the transmission modes registered in the selected table as the transmission mode used for the first radio apparatus (2).