| 摘要 |
PURPOSE:To inversely quantize QAM signals with less carrier and to decode OFDM signals by constituting a transmitter by a symbol number counting circuit and an IFFT circuit and constituting a receiver by an FF circuit and the symbol number counting circuit. CONSTITUTION:The IFFT and pilot signal generation circuit 3 of an orthogonal frequency division multiplex OFDM signal transmitter is operated by clock signals from a clock signal generation circuit 10. 256 orthogonal amplitude modulation is performed to the carrier of 248 waves and respective output signals are outputted as real R and imaginary I components. Also, the discrete frequency point information of the circuit 3 is transmitted as Nyquist frequency information which is the value of 1/2 of a cycle N. Thus, in the receiver, the Nyquist signal information is decoded and multipled and sampling position signals for operating an FFT circuit are prepared. The Nyquist frequency information is obtained by impressing the signals of a fixed level to the imaginary number input terminal I and the real number input terminal R of N/2 of the circuit 3. |
