Abstract: The present invention relates to a decoding method for a raptor codes using system, which is capable of improving performance of the system and limiting increase in the amount of computation by grouping variable nodes if raptor codes are unsuccessfully decoded, to thereby increase a conjecture efficiency of variable node values. The decoding method is capable of improving performance of the system by making it possible to achieve performance improvement and additional reduction of the amount of computation even under an application of MP decoding by grouping variable nodes whose values cannot be known when decoded, dividing groups of variable nodes into sub groups, and conjecturing and recovering the variable nodes in a manner to exclude sub groups which do not satisfy check node equation.

Abstract: 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.

Abstract: A multi-coexistence communication technology is provided. A multi-coexistence communication system based on an interference-aware environment and a method for operating the same can remove interference detected using an interference temperature limit from at least one transmission signal and transmit the signal to a main/sub communication terminal during data communication on a wired/wireless communication network formed of a main base station, a sub base station, the main communication terminal, and the sub communication terminal, thereby smoothly providing a high-speed seamless data transmission service based on a multi-coexistence communication environment where a distributed small-scale network requiring a low transmission rate, a medium-scale network for providing various wireless communication services, and a large-scale broadcasting network requiring a high transmission rate and high quality coexist, and preventing congestion due to increased demand for frequency resources.

Abstract: A block interleaving apparatus for block interleaving M-bit input streams to be transferred with a modulus k using a mixed radix system in a multi-band orthogonal frequency division multiplexing communication system, including an array processor having an array including M cells in which the number of columns is k and the number of rows is M/k. The array processor inputs the input streams from the bottom-right cell up to the top-left last cell in the horizontal direction, and, after the first bit of the input streams reaches the last cell, generates interleaved output streams by changing the output of the array processor from horizontal direction to vertical direction.

Abstract: A block interleaving apparatus for block interleaving M-bit input streams to be transferred with a modulus k using a mixed radix system in a multi-band orthogonal frequency division multiplexing communication system, including an array processor having an array including M cells in which the number of columns is k and the number of rows is M/k. The array processor inputs the input streams from the bottom-right cell up to the top-left last cell in the horizontal direction, and, after the first bit of the input streams reaches the last cell, generates interleaved output streams by changing the output of the array processor from horizontal direction to vertical direction.

Abstract: Disclosed is a method for detecting a symbol using a trellis structure on a multiple input multiple output (MIMO) mobile communication system. The method includes the steps of: setting a plurality of states by grouping symbols producible from a receiving signal in the unit of sub-states; calculating metric values for paths inputted to the sub-states and selecting paths having the calculated metric values smaller than a preset first threshold, as first surviving paths; setting a second threshold based on an accumulated metric value of a path having the smallest accumulated metric in each of the states; and selecting paths having metric value smaller than the second threshold, as second surviving paths, among the first surviving paths selected for each state.

Abstract: 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.

Abstract: 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.

Abstract: 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.