Patent ID: 7684502

Claim:
A transmission/reception apparatus for transmitting a signal which is modulated based on input data to another apparatus on a communication network, and receiving a signal from another apparatus on the communication network and demodulating the received signal, comprising: a multicarrier-modulation transmission section for modulating a plurality of carriers having respectively different frequencies based on the input data, and transmitting the modulated signal to another apparatus on the communication network; a multicarrier reception/demodulation section for receiving a multicarrier-modulated signal transmitted from another apparatus on the communication network and demodulating the multicarrier-modulated signal; and a control section for, if a predetermined activation condition is satisfied, communicating with another apparatus on the communication network acting as a counterpart of communication, executing two or more instances of a channel estimation algorithm for evaluating transmission quality on a transmission path with respect to a frequency of each carrier, and controlling, based on the transmission quality evaluated through the two or more instances of the channel estimation algorithm executed, a modulation rule to be used in the multicarrier-modulation transmission section or a demodulation rule to be used in the multicarrier reception/demodulation section, wherein the transmission path is a power line to which commercial electric power is applied, and a time interval between two adjacent instances of the channel estimation algorithm to be executed is unequal to an integer multiple of a cycle of the commercial electric power and unequal to an integer multiple of half the cycle of the commercial electric power.