OFDM-CDMA equipment and method
An OFDM signal transmission apparatus is provided, which includes a mapping unit configured to map first signals into N subcarriers and second signals into M subcarrier(s) to form an OFDM signal, wherein N is larger than M. The first signals are each indicating a same bit of retransmission information and the second signals are each indicating a same bit of information other than retransmission information. The OFDM signal transmission apparatus further includes a transmitting unit configured to transmit the formed OFDM signal.
1. An OFDM signal receiving apparatus comprising:
a receiving section configured to receive first modulated signals corresponding to data 1 of a specific packet that are mapped into a first number of subcarriers and to receive second modulated signals corresponding to data 2 of a packet other than the specific packet that are mapped into a second number of subcarriers, the specific packet including retransmission information, the first number of subcarriers of the first modulated signals including the same data as the data 1 , and the second number of subcarriers of the second modulated signals including the same data as the data 2 ; and
a demodulating section configured to demodulate the received first modulated signals and the received second modulated signals,
wherein the first number is larger than the second number.
2. The OFDM signal receiving apparatus according to claim 1 , wherein
the second number equals one.
3. The OFDM signal receiving apparatus according to claim 1 , wherein
the demodulating section demodulates the second modulated signals by using a signal included in one of the second number of subcarriers.
4. The OFDM signal receiving apparatus according to claim 3 , wherein
the demodulating section selects said one of the second number of subcarriers based on reception qualities.
5. The OFDM signal receiving apparatus according to claim 1 , wherein
the demodulating section demodulates the second modulated signals by using a combined signal based on the received second modulated signals.
6. An OFDM signal receiving method comprising:
receiving first modulated signals corresponding to data 1 of a specific packet that are mapped into a first number of subcarriers, and second modulated signals corresponding to data 2 of a packet other than the specific packet that are mapped into a second number of subcarriers, the specific packet including retransmission information, the first number of subcarriers of the first modulated signals including the same data as the data 1 , and the second number of subcarriers of the second modulated signals including the same data as the data 2 ; and
demodulating the received first modulated signals and the received second modulated signals,
wherein the first number is larger than the second number.
7. The OFDM signal receiving method according to claim 6 , wherein
the second number equals one.
8. The OFDM signal receiving method according to claim 6 , wherein
the demodulating step includes demodulating the second modulated signals by using a signal included in one of the second number of subcarriers.
9. The OFDM signal receiving method according to claim 8 , wherein
said one of the second number of subcarriers is selected based on reception qualities.
10. The OFDM signal receiving method according to claim 6 , wherein
the demodulating step includes demodulating the second modulated signals by using a combined signal based on the received second modulated signals.