OFDM transmission signal generation apparatus and method, and OFDM reception data generation apparatus and method

An OFDM reception data generation apparatus which receives a plurality of OFDM signals that were sent over an identical frequency band at an identical time period, said OFDM reception data generation apparatus comprising:

• a Fourier transform section configured to convert the plurality of OFDM signals to a plurality of reception signals, each of the plurality of reception signals including a preamble period and a data period, and comprising several pilot carriers in the data period, the several pilot carriers being located in identical carrier positions among the plurality of reception signals, such that orthogonal pilot sequences are assigned to identical time slots of pilot carriers in identical carrier positions among the plurality of reception signals, and identical pilot sequences are assigned to at least two of the plurality of reception signals;
• and
• a demodulator configured to estimate transmission path fluctuation using the preamble period of the plurality of reception signals to generate a transmission path fluctuation signal;
• estimate at least one of phase fluctuation and frequency offset by using pilot symbols arranged in the several pilot carriers to generate at least one of a phase fluctuation signal and a frequency offset signal;
• and demodulate the data period of the plurality of reception signals by using the transmission path fluctuation signal and at least one of the phase fluctuation signal and the frequency offset signal to generate reception data.

An OFDM reception data generation method for receiving a plurality of OFDM signals that were sent over an identical frequency band at an identical time period, said OFDM reception data generation method comprising:

• converting the plurality of OFDM signals to plurality of reception signals, each of the plurality of reception signals including a preamble period and a data period, and comprising several pilot carriers in the data period, the several pilot carriers being located in identical carrier positions among the plurality of reception signals, such that orthogonal pilot sequences are assigned to identical time slots of pilot carriers in identical carrier positions among the plurality of reception signals, and identical pilot sequences are assigned to at least two of the plurality of reception signals;
• estimating transmission path fluctuation using the preamble period of the plurality of reception signals to generate a transmission path fluctuation signal;
• estimating at least one of phase fluctuation and frequency offset by using pilot symbols arranged in the several pilot carriers to generate at least one of a phase fluctuation signal and a frequency offset signal;
• and
• demodulating the data period of the plurality of reception signals by using the transmission path fluctuation signal and at least one of the phase fluctuation signal and the frequency offset signal to generate reception data.