Transmission and reception signal processor and method

A transmission method comprising:

• mapping reference signals in first sub-carriers at a first time and in second sub-carriers at a second time for first Orthogonal Frequency Division Multiplexing (OFDM) signals, wherein no signal is mapped in the second sub-carriers at the first time and in the first sub-carriers at the second time for the first OFDM signals;
• mapping reference signals in the second sub-carriers at the first time and in the first sub-carriers at the second time for a second OFDM signals, wherein no signal is mapped in the first sub-carriers at the first time and in the second sub-carriers at the second time for the second OFDM signals;
• and
• transmitting the first OFDM signals and the second OFDM signals from different antennas.

A reception apparatus comprising:

• a receiver, which, in operation, receives first Orthogonal Frequency Division Multiplexing (OFDM) signals and second OFDM signals transmitted from different antennas,
• wherein the first OFDM signals are generated from reference signals mapped in first sub-carriers at a first time and in second sub-carriers at a second time, wherein no signal is mapped in the second sub-carriers at the first time and in the first sub-carriers at the second time for the first OFDM signals, and
• the second OFDM signals are generated from reference signals mapped in the second sub-carriers at the first time and in the first sub-carriers at the second time, wherein no signal is mapped in the first sub-carriers at the first time and in the second sub-carriers at the second time for the second OFDM signals;
• and
• circuitry, which is coupled to the receiver and which, in operation, uses the reference signals to demodulate data included in the first OFDM signals and the second OFDM signals.

A reception method comprising:

• receiving first Orthogonal Frequency Division Multiplexing (OFDM) signals and second OFDM signals transmitted from different antennas,
• wherein the first OFDM signals are generated from reference signals mapped in first sub-carriers at a first time and in second sub-carriers at a second time, wherein no signal is mapped in the second sub-carriers at the first time and in the first sub-carriers at the second time for the first OFDM signals, and
• the second OFDM signals are generated from reference signals mapped in the second sub-carriers at the first time and in the first sub-carriers at the second time, wherein no signal is mapped in the first sub-carriers at the first time and in the second sub-carriers at the second time for the second OFDM signals;
• and
• using the reference signals to demodulate data included in the first OFDM signals and the second OFDM signals.