Pilot pattern design for a STTD scheme in an OFDM system
View Patent ↗A transmitting device for transmitting data symbols and pilot symbols in an OFDM transmission system; the device comprising symbol generating means for generating said data symbols and said pilot symbols, means for transmitting said data symbols and pilot symbols respectively by using a plurality of subcarriers of said OFDM transmission system, wherein said symbol generating means is designed to selectively generate a first type pilot symbol and a second type pilot symbol being orthogonal to said first type pilot symbol so that a pilot symbol pattern in the frequency dimension comprises at least said first type pilot symbol to be transmitted by using a predefined subcarrier and second type pilot symbol to be transmitted by using other predefined subcarrier, and wherein said pilot symbol pattern has a different pattern from a succeeding pilot symbol pattern in time dimension.
1. A transmitter that transmits data symbols in an orthogonal frequency division multiplex (OFDM) system, the transmitter comprising:
circuitry configured to control transmission of:
a first pair of symbols for channel estimation via a first subcarrier from a first source, the first pair of symbols based on a first pattern;
a second pair of symbols for channel estimation via the first subcarrier from a second source spatially different from the first source, the second pair of symbols based on a second pattern and being orthogonal to the first pair of symbols;
a first data symbol from one of the first source and the second source; and
a second data symbol from another of the first source and the second source.
2. The transmitter of claim 1 , wherein
a first symbol of the first pair of symbols and a first symbol of the second pair of symbols are identical, and
a second symbol of the second pair of symbols is inverted with respect to a second symbol of the first pair of symbols.
3. The transmitter of claim 1 , wherein
a first symbol of the second pair of symbols is inverted with respect to a first symbol of the first pair of symbols, and
a second symbol of the first pair of symbols and a second symbol of the second pair of symbols are identical.
4. The transmitter of claim 1 , wherein
the circuitry is further configured to control transmission of a third pair of symbols via a second subcarrier from the first source, the third pair of symbols being transmitted at a same time as the first pair of symbols and being orthogonal to the first pair of symbols.
5. The transmitter of claim 4 , wherein
the circuitry is configured to perform linear interpolation using a combination of at least two symbols selected from among a symbol from the first pair of symbols, a symbol from the second pair of symbols and a symbol from the third pair of symbols.
6. The transmitter of claim 1 , wherein
the circuitry is configured to encode the first data symbol and the second data symbol,
the first data symbol includes a first data symbol portion and a second data symbol portion, and
the second data symbol includes a negative conjugate of the second data symbol portion and a conjugate of the first data symbol portion.
7. The transmitter of claim 1 , wherein
the circuitry is configured to control transmission of the first pair of symbols via a first antenna and transmit the second pair of symbols via a second antenna that is spatially different from the first antenna.
8. The transmitter of claim 1 , wherein
each symbol of the first pair of symbols and the second pair of symbols is a complex value.
9. A receiver that receives data symbols in an orthogonal frequency division multiplex (OFDM) system, the receiver comprising:
circuitry configured to receive:
a first pair of symbols for channel estimation via a first subcarrier from a first source, the first pair of symbols based on a first pattern;
a second pair of symbols for channel estimation via the first subcarrier from a second source spatially different from the first source, the second pair of symbols based on a second pattern and being orthogonal to the first pair of symbols;
a first data symbol from one of the first source and the second source; and
a second data symbol from another of the first source and the second source.
10. The receiver of claim 9 , wherein
a first symbol of the first pair of symbols and a first symbol of the second pair of symbols are identical, and
a second symbol of the second pair of symbols is inverted with respect to a second symbol of the first pair of symbols.
11. The receiver of claim 9 , wherein
a first symbol of the second pair of symbols is inverted with respect to a first symbol of the first pair of symbols, and
a second symbol of the first pair of symbols and a second symbol of the second pair of symbols are identical.
12. The receiver of claim 9 , wherein
the circuitry is further configured to receive a third pair of symbols via a second subcarrier from the first source, the third pair of symbols being transmitted at a same time as the first pair of symbols and being orthogonal to the first pair of symbols.
13. The receiver of claim 9 , wherein
the circuitry is configured to perform channel estimation based on the first pair of symbols and the second pair of symbols.
14. The receiver of claim 12 , wherein
the circuitry is configured to perform linear interpolation using a combination of at least two symbols selected from among a symbol from the first pair of symbols, a symbol from the second pair of symbols and a symbol from the third pair of symbols.
15. The receiver of claim 9 , wherein
the circuitry is configured to decode the first data symbol and the second data symbol,
the first data symbol includes a first data symbol portion and a second data symbol portion, and
the second data symbol includes a negative conjugate of the second data symbol portion and a conjugate of the first data symbol portion.
16. The receiver of claim 9 , further comprising:
an antenna configured to receive the first pair of symbols, the second pair of symbols, the first data symbol and the second data symbol.
17. The receiver of claim 9 , wherein
each symbol of the first pair of symbols and the second pair of symbols is a complex value.
18. A transmitter that transmits data symbols in an orthogonal frequency division multiplex (OFDM) system, the transmitter comprising:
circuitry configured to control transmission of:
a first pilot symbol pattern via a first subcarrier from a first source and a second source, the second source being spatially different from the first source;
a second pilot symbol pattern via a second subcarrier from the first source and the second source, the second pilot symbol pattern being orthogonal to the first pilot symbol pattern;
first data from one of the first source and the second source; and
second data from another of the first source and the second source.
19. The transmitter of claim 18 , wherein
the first pilot symbol pattern and the second pilot symbol pattern are arranged in a frequency domain.
20. The transmitter of claim 18 , wherein
the circuitry is configured to:
encode the first data, which includes a first data portion and a second data portion; and
output a negative conjugate of the second data portion and a conjugate of the first data portion.
21. The transmitter of claim 18 , further comprising:
a plurality of antennas configured to transmit the first pilot symbol pattern, the second pilot symbol pattern, the first data and the second data.
22. The transmitter of claim 18 , wherein
each pilot symbol included in the first pilot symbol pattern and the second pilot symbol pattern is a complex value.
23. A receiver that receives data symbols in an orthogonal frequency division multiplex (OFDM) system, the transmitter comprising:
circuitry configured to receive:
a first pilot symbol pattern via a first subcarrier from a first source and a second source, the second source being spatially different from the first source;
a second pilot symbol pattern via a second subcarrier from the first source and the second source, the second pilot symbol pattern being orthogonal to the first pilot symbol pattern;
first data from one of the first source and the second source; and
second data from another of the first source and the second source.
24. The receiver of claim 23 , wherein
the first pilot symbol pattern and the second pilot symbol pattern are arranged in a frequency domain.
25. The receiver of claim 23 , wherein
the circuitry is configured to perform channel estimation based on the first pilot symbol pattern and the second pilot symbol pattern.
26. The receiver of claim 23 , wherein
the circuitry is configured to perform linear interpolation on the first pilot symbol pattern and the second pilot symbol pattern.
27. The receiver of claim 23 , wherein
the circuitry is configured to decode the first data and the second data,
the first data includes a first data portion and a second data portion, and
the second data symbol includes a negative conjugate of the second data portion and a conjugate of the first data portion.
28. The receiver of claim 23 , further comprising:
an antenna configured to receive the first pilot symbol pattern, the second pilot symbol pattern, the first data and the second data.
29. The receiver of claim 23 , wherein
each pilot symbol included in the first pilot symbol pattern and the second pilot symbol pattern is a complex value.