Patent ID: 7565114

Claim:
A receiver apparatus for receiving, by a plurality of receiver antennas, transmission signals transmitted from a transmitter apparatus by a plurality of transmitter antennas in a parallel manner and for estimating a channel matrix for causing the transmission signals to be related to received signals to demodulate the received signals based upon said channel matrix; the receiver apparatus comprising: calculation means for calculating a physical amount so as to estimate a radio line quality with respect to each of signal series based upon only said channel matrix; determination means for evaluating the radio line quality based upon the physical amount calculated by said calculation means so as to determine a transmission parameter in a next transmission operation by said transmitter apparatus with respect to each of the signal series; transmission means for transmitting the transmission parameter determined by said determination means to said transmitter apparatus; and detection means for detecting a change in the transmission parameter from the received signals with respect to each of the signal series, wherein the transmission parameter is a modulation level in mapping.