Patent ID: 7302240
Filing Date: 2007-11-27
Classification: H04B,H04L

Abstract:
1. A communication apparatus which carries out multicarrier modulation processing, comprising a receiving device including: an analog-to-digital converter which converts an analog signal which was received, into a digital signal; a transformer which generates an in-phase signal and a orthogonal signal by converting a reception signal; a carrier detector for detecting the reception signal; a synchronous circuit for being synchronized with the reception signal; an equalizer for compensating a distorted signal due to influence of a transmission channel; a channel estimation unit which determines a modulation scheme of primary modulation which is used by each sub carrier of a symbol mapper in a transmitting device, by use of a result of transmission channel estimation; and a decision unit which carries out a decision by use of the signal which is outputted from said equalizer, wherein said channel estimation unit carries out plural times of transmission channel estimations to a transmission channel estimation request, and in a case of using a power line as the transmission channel, said channel estimation unit carries out the transmission channel estimation for a period cycle which is nearly equal to an AC cycle of a power supply cycle.