OFDM transmission/reception system and transmitting/receiving apparatus

An OFDM transmitting apparatus comprising:

• reference symbol generating means for generating data for frequency reference symbols corresponding to non-equidistant positions among carrier positions assigned at equidistances along a frequency axis;
• multiplexing means for multiplexing at least data for said frequency reference symbols and data for a main information symbol;
• OFDM modulation means for performing OFDM modulation on a plurality of carriers with an output of said multiplexing means;
• and
• quadrature modulation means for performing quadrature modulation on an output of said OFDM modulation means.

An OFDM receiving apparatus comprising:

• carrier generating means for generating carriers;
• quadrature demodulation means for receiving an OFDM modulation wave including a frequency reference symbol and performing quadrature demodulation of said OFDM modulation wave with the output of said carrier generating means;
• OFDM demodulation means for performing OFDM demodulation using an output of said quadrature demodulation means;
• first frequency control means for detecting a carrier frequency offset using said output of said quadrature demodulation means and supplying a first carrier compensation signal based on said carrier frequency offset to said carrier generating means;
• and
• second frequency pattern of transmitted carries using an frequency reference symbol included in an OFDM demodulation output from said OFDM demodulation means, comparing said detected carrier arrangement pattern with a predetermined carrier arrangement pattern to detect a carrier frequency offset and supplying a second carrier compensation signal based on that frequency offset to said carrier generating means.