A reception quality notifying method improves upstream-line throughput by reducing the data amount of reception quality data of downstream multicarrier signals to be transmitted in the upstream line. A low-power consumption base station apparatus and a wireless communication terminal apparatus may employ the reception quality notifying method. When a wireless communication terminal apparatus receives a downstream multicarrier signal and then notifies a base station apparatus of a subcarrier having a desirable reception quality for the downstream multicarrier signal, the wireless communication terminal apparatus produces reception quality data of a plurality of formats, then selects, from among the produced reception quality data, one having the lowest data mount. The selected reception quality data is transmitted to the base station apparatus by use of an upstream multicarrier signal subcarrier designated by the base station apparatus.