摘要:
The present invention provides a method and apparatus for transmitting a preamble for multiple channel estimation. The method includes generating a channel estimation sequence, allocating the channel estimation sequence to some of a plurality of symbols in which a preamble is transmitted, and transmitting the preamble. The channel estimation sequence is generated by bisecting a sequence having a length N, generating a first sequence and a second sequence by adding a Zero-padded Suffix (ZS) having a zero value to a last part of each of the two bisected sequences, copying the first sequence and the second sequence at least once, and allocating the first sequences and the second sequences to some of the symbols.
摘要:
The present invention provides a method and apparatus for transmitting a preamble for multiple channel estimation. The method includes generating a channel estimation sequence, allocating the channel estimation sequence to some of a plurality of symbols in which a preamble is transmitted, and transmitting the preamble. The channel estimation sequence is generated by bisecting a sequence having a length N, generating a first sequence and a second sequence by adding a Zero-padded Suffix (ZS) having a zero value to a last part of each of the two bisected sequences, copying the first sequence and the second sequence at least once, and allocating the first sequences and the second sequences to some of the symbols.
摘要:
A method of adaptive modulation in an OFDM system with channel evaluation with two types of adaptive transmission schemes that include several modulation schemes to achieve efficient transmission service. By evaluating channel environment, the methods select the proper modulation scheme among the BPSK, QPSK, 16QAM, and 64QAM. Therefore, the methods either increase the performance or reduce the signaling overhead. By using the method, the reliable and efficient transmission services are achieved.
摘要:
A method of enhanced detection technique is used with wireless MIMO communication system. Since the performance of V-BLAST system depends on the first sub-stream detection capability, V probable streams are detected according to the first detected sub-stream of DFE detector and most probable stream is selected by likelihood test. The performance of the V-BLAST system can be improved and the decoding complexity and system performance can be controlled by adjusting the number of V.
摘要:
Disclosed is a method of estimating carrier frequency offset in an OFDM system. The method includes the steps of forming one OFDM symbol which has M repeated identical signal block, being a base sub-block; forming a 2i number of identical ith sub-blocks using an M/2i number of the M number of base sub-blocks as a unit; and estimating an ith carrier frequency offset &egr;i using a correlation between two adjacent ith sub-blocks in the 8i number of the ith sub-blocks.
摘要:
The diversity techniques—space time block code (STBC), maximum ratio combining (MRC)—with multiple antennas provide better reliability than general system. But there are some limitations such as size, cost, hardware complexity, etc, because of multiple antennas. In this letter, we propose a cooperative transmission technique using STBC. We can overcome those limitations and give the gain of cooperative transmission diversity in a concept of virtual multi-input multi-output (MIMO) with single transmit antenna.
摘要:
The diversity techniques—space time block code (STBC), maximum ratio combining (MRC)—with multiple antennas provide better reliability than general system. But there are some limitations such as size, cost, hardware complexity, etc, because of multiple antennas. In this letter, we propose a cooperative transmission technique using STBC. We can overcome those limitations and give the gain of cooperative transmission diversity in a concept of virtual multi-input multi-output (MIMO) with single transmit antenna.