ABCLabOwing to rapid development of the semiconductor industry and increase in demand for multimedia services, there has been additional interest in construction of high speed data communication networks and mobile communication systems which can transmit huge amount of data as fast as possible. In order to store, recover and transmit the data efficiently with the restriction of limited resources, digital signals should be processed appropriately to fit the various recording and/or transmission channels and communication environments. For the purpose of achieving these objectives, the following research activities in the fields of coding and decoding, modulation and demodulation , signal transmission and processing are carried out in the Advanced Broadcasting & Communications Laboratory(ABC). ~Owing to rapid development of the semiconductor industry and increase in demand for multimedia services, there has been additional interest in construction of high speed data communication networks and mobile communication systems which can transmit huge amount of data as fast as possible. In order to store, recover and transmit the data efficiently with the restriction of limited resources, digital signals should be processed appropriately to fit the various recording and/or transmission channels and communication environments. For the purpose of achieving these objectives, the following research activities in the fields of coding and decoding, modulation and demodulation , signal transmission and processing are carried out in the Advanced Broadcasting & Communications Laboratory(ABC).
Field 1 : Coding and Decoding
Research is already underway on optimizing error control line codes which combine error control and line codes into single codes and many research results have been published and presented in various domestic and international journals as well as at conferences. More recently, Turbo Codes, and Low Density Paity Codes which are known to be the most powerful error correcting codes up to now is a major research concern. Especially, design of efficient interleavers and low power decoders for application in the next generation mobile communication systems such as cdma 2000 and IMT-2000 is well in progress. In addition, adaptive coding techniques e.g. hybrid ARQ schemes are also studied.
Field 2 : Digital Modulation and Demodulation
In the field of modulation and demodulation, the topics studied are trellis coded modulation(TCM) which combines coding and modulation processes, coded orthogonal frequency division multiplexing(COFDM) for future digital broadcasting systems, polarization shift keying(POLSK) which is an efficient multilevel modulation scheme for optical communication systems, multicarrier modulation(MCM) which can utilize efficiently the limited bandwidth of the conventional communication channels. Adaptive modulation schemes which can give better performance on time varying channels such as mobile communication systems are also the key research topics like the adaptive coding.