Transmission signal generation apparatus, transmission signal generation method, reception signal apparatus, and reception signal method
View Patent ↗Multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) communication is provided which allows high accuracy estimation of frequency offset, high accuracy estimation of a transmission path fluctuation and high accuracy synchronization/signal detection. Pilot symbol mapping is provided for forming pilot carriers by assigning orthogonal sequences to corresponding subcarriers among OFDM signals which are transmitted at the same time from respective antennas in the time domain. Even when pilot symbols are multiplexed among a plurality of channels (antennas), this allows frequency offset/phase noise to be estimated with high accuracy.
1. A transmission signal generation apparatus comprising:
a mapper configured to generate one or more transmission signals, each transmission signal including a data frame having preamble information, pilot information, and data information,
wherein each of the one or more transmission signals includes:
an associated preamble multiplied by a factor so that an average reception power of the associated preamble corresponds to an average reception power of the data information received with the associated preamble,
plural pilot symbol sequences; and
an Inverse Fourier transformer configured to:
generate for each of the one or more transmission signals a corresponding Orthogonal Frequency Division Multiplexed (OFDM) signal for transmission by a corresponding one of one or more antennas by Inverse Fourier transforming each of the transmission signals,
wherein:
the Inverse Fourier transformer is configured to arrange:
the pilot symbol sequences in corresponding pilot carriers during a first time period, and
sets of the pilot carriers in a same carrier position in the OFDM signal, and
wherein the plural pilot symbol sequences are all orthogonal to each other.
2. The transmission signal generation apparatus of claim 1 , wherein the one or more antennas includes one, two, three, or four antennas.
3. The transmission signal generation apparatus of claim 1 , wherein each transmission signal can include multiple preamble sequences and multiple pilot subcarriers.
4. The transmission signal generation apparatus of claim 1 , wherein symbol values for the plural pilot symbol sequences are from a set {1, −1}.
5. The transmission signal generation apparatus of claim 1 , wherein symbol values for the associated preambles are from a set {1+j, −1−j}.
6. A transmission signal generation method comprising:
generating one or more transmission signals, each transmission signal including a data frame having preamble information, pilot information, and data information,
wherein each of the one or more transmission signals includes:
an associated preamble multiplied by a factor so that an average reception power of the associated preamble corresponds to an average reception power of the data information received with the associated preamble, and
plural pilot symbol sequences;
performing Inverse Fourier transform operations including:
generating for each of the one or more transmission signals a corresponding Orthogonal Frequency Division Multiplexed (OFDM) signal for transmission by a corresponding one of one or more antennas by Inverse Fourier transforming each of the transmission signals,
arranging the pilot symbol sequences in corresponding pilot carriers during a first time period, and
arranging sets of the pilot carriers in a same carrier position in the OFDM signal,
wherein the plural pilot symbol sequences are all orthogonal to each other.
7. The transmission signal generation method of claim 6 , wherein the one or more antennas includes one, two, three, or four antennas.
8. The transmission signal generation method of claim 6 , wherein each transmission signal can include multiple preamble sequences and multiple pilot subcarriers.
9. The transmission signal generation method of claim 6 , wherein symbol values for the plural pilot symbol sequences are from a set {1, −1}.
10. The transmission signal generation method of claim 6 , wherein symbol values for the plural pilot symbol sequences are from a set {1+j, −1−j}.
11. A signal reception apparatus comprising:
processing circuitry including a Fourier transformer configured to input and process from one or more antennas one or more Orthogonal Frequency Division Multiplexed (OFDM) signals, each OFDM signal including a data frame having preamble information, pilot information, and data information,
wherein each of the one or more OFDM signals includes:
an associated preamble multiplied by a factor so that an average reception power of the associated preamble corresponds to an average reception power of the data information received with the associated preamble, and
plural pilot symbol sequences in corresponding pilot carriers during a first time period with sets of the pilot carriers being in a same carrier position in the OFDM signal,
wherein the plural pilot symbol sequences are all orthogonal to each other.
12. The signal reception apparatus of claim 11 , wherein the one or more antennas includes one, two, three, or four antennas.
13. The signal reception apparatus of claim 11 , wherein each OFDM signal can include multiple preamble sequences and multiple pilot subcarriers.
14. The signal reception apparatus of claim 11 , wherein symbol values for the plural pilot symbol sequences are from a set {1, −1}.
15. The signal reception apparatus of claim 11 , wherein symbol values for the associated preambles are from a set {1+j, −1−j}.
16. A signal reception method comprising:
inputting from one or more antennas and processing one or more Orthogonal Frequency Division Multiplexed (OFDM) signals, each OFDM signal including a data frame having preamble information, pilot information, and data information,
wherein each of the one or more OFDM signals includes:
an associated preamble multiplied by a factor so that an average reception power of the associated preamble corresponds to an average reception power of the data information received with the associated preamble, and
plural pilot symbol sequences in corresponding pilot carriers during a first time period with sets of the pilot carriers being in a same carrier position in the OFDM signal,
wherein the plural pilot symbol sequences are all orthogonal to each other.
17. The signal reception method of claim 16 , wherein the one or more antennas includes one, two, three, or four antennas.
18. The signal reception method of claim 16 , wherein each transmission signal can include multiple preamble sequences and multiple pilot subcarriers.
19. The signal reception method of claim 16 , wherein symbol values for the plural pilot symbol sequences are from a set {1, −1}.
20. The signal reception method of claim 16 , wherein symbol values for the plural pilot symbol sequences are from a set {1+j, −1−j}.