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US 6,714,511 B1Granted
OFDM transmission/reception apparatus having a guard interval length changing function
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsHiroaki Sudo, Mitsuru Uesugi
Life of this patent
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Abstract
The subtractor of the reception system calculates the channel quality using an optimal guard interval length detection signal inserted into one carrier by the transmission system, then the optimal guard interval length detector calculates the minimum guard interval length necessary to eliminate delayed signals using this calculated channel quality, inserts the control signal indicating this guard interval length into one carrier and the reception system sets the guard interval length using this control signal.
Claims27
An OFDM transmission/reception apparatus comprising:
- a guard interval inserter that inserts part of a valid symbol at the start of the valid symbol of a transmission signal as a guard interval;
- a guard interval length regulator that extends/contracts the length of the guard interval that the guard interval inserter inserts into the transmission signal;
- a first inserter that inserts a guard interval length detection signal comprising a plurality of symbols indicating different guard interval lengths into one carrier of said transmission signal;
- and
- a second inserter that inserts a guard interval length selection control signal into one carrier of said transmission signal.
2 more elements
An OFDM transmission/reception apparatus comprising:
- a guard interval inserter that inserts part of a valid symbol at the start of the valid symbol of a transmission signal as a guard interval;
- a guard interval length regulator that extends/contracts the guard interval length that the guard interval inserter inserts into the transmission signal;
- an inserter that inserts a guard interval length detection signal comprising a plurality of symbols indicating different guard interval lengths into one carrier of said transmission signal;
- an extractor that extracts the decision error of a guard interval length detection signal from among the reception signals using the same frequency as that of the transmission signal;
- and
- a guard interval length controller that controls said guard interval length regulator based on the output of the extractor.
3 more elements
An OFDM transmission/reception apparatus comprising:
- a guard interval inserter that inserts part of a valid symbol at the start of the valid symbol of a transmission signal as a guard interval;
- a guard interval length regulator that extends/contracts the guard interval length that the guard interval inserter inserts into the transmission signal;
- a first inserter that inserts a guard interval length detection signal into one carrier of the transmission signal;
- a second inserter that inserts a plurality of frame synchronization acquisition known signals indicating different guard interval lengths into one carrier of the transmission signal;
- a first extractor that extracts the decision error of a guard interval length detection signal from among the reception signal;
- a known signal selection controller that is instructed which frame synchronization acquisition known signal should be inserted by said second inserter based on the output of the first extractor;
- a second extractor that extracts a frame synchronization acquisition known signal from the demodulated reception signal;
- and
- a guard interval length controller that controls said guard interval length regulator so that the guard interval length is set to the guard interval length indicated by the known signal output by said second extractor.
6 more elements
A communication terminal apparatus have an OFDM transmission/reception apparatus, said OFDM transmission/reception apparatus comprising:
- a guard interval inserter that inserts part of a valid symbol at the start of the valid symbol of a transmission signal as a guard interval;
- a guard interval length regulator that extends/contracts the guard interval length that the guard interval inserter inserts into the transmission signal;
- a first inserter that inserts a guard interval length detection signal comprising a plurality of symbols indicting different guard interval lengths into one carrier of said transmission signal;
- and
- a second inserter that inserts a guard interval length selection control signal into one carrier of said transmission signal.
2 more elements
A base station apparatus having an OFDM transmission/reception apparatus, said OFDM transmission/reception apparatus comprising:
- a guard interval inserter that inserts part of a valid symbol at the start of the valid symbol of a transmission signal as a guard interval;
- a guard interval length regulator that extends/contracts the guard interval length that the guard interval inserter inserts into the transmission signal;
- a first inserter that inserts a guard interval length detection signal comprising a plurality of symbols indicating different guard interval lengths into one carrier of said transmission signal;
- and
- a second inserter that inserts a guard interval length selection control signal into one carrier of said transmission signal.
2 more elements
An OFDM transmission/reception method comprising:
- the guard interval inserting step of inserting part of a valid symbol at the start of the valid symbol of a transmission signal as a guard interval;
- the guard interval length regulating step of extending/contracting the guard interval length that the guard interval inserting step inserts into the transmission signal;
- the first inserting step of inserting a guard interval length detection signal comprising a plurality of symbols indicating different guard interval lengths into one carrier of said transmission signal;
- and
- the second inserting step of inserting a guard interval length selection control signal into one carrier of said transmission signal.
2 more elements
Dependencies are inferred from the claim text.