• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1996.10a
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• pp.1105-1108
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• 1996

• Journal of Navigation and Port Research
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• v.36 no.10
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• pp.845-849
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• 2012

The next-generation wireless communication requires fast transmission speeds with various services and high reliability. In order to satisfy these needs we study MIMO system used layered space time coded system (LST) combining space time trellis codes (STTC) with turbo codes. In LST, two codes that are inner and outer codes are concatenated in the serial fashion. The inner codes are turbo Pi codes suggested in DVB-RCS NG system, and outer codes are STTC codes proposed by Blum. The interleaver technique is used to efficiently combine two codes. And we proposed and simulated that a full iteration method between turbo decoder and BCJR decoder to improve the performance instead of only processing inner-iteration turbo decoder. The simulation results of proposed effective layered method show improving BER performance about 1.3~1.5dB than conventional one.

• Proceedings of the KIEE Conference
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• 1998.07g
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• pp.2467-2469
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• 1998

We examine the performance of high-speed non-directed infrared links using pulse-position modulation (PPM) with trellis-coded modulation (TCM) to mitigate the effects of multipath-induced intersymbol interference(ISI) on such links. Using the measured characteristics of multipath indoor infrared channels, we calculate BER curves and ISI power penalties for maximum-likelihood sequence detection of 8-PPM links using rate-2/3 trellis codes operation at 10 and 30Mb/s. Our results indicate that the suggested decoder of PPM with TCM is a very promising decoder on high-speed non-directed infrared channels.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.11
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• pp.33-38
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• 2004

In this paper, we review a trellis-coded orthogonal frequency division multiplex (TC-OFDM) system, which combines OFDM with trellis-coded modulation, for overcoming the frequency selective and multipath fading of time dispersive channels. We simulate and analyse the BER performance of rate 2/3 trellis coded 8DPSK-OFDM over time dispersive channels. Design of the trellis codes at different carrier numbers of OFDM is discussed. Results show that TC-OFDM system can provide 6 dB coding gain at a BER of 10$^{-3}$ compared with OFDM system without coding.

• Journal of the Institute of Convergence Signal Processing
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• v.1 no.2
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• pp.105-114
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• 2000

In this paper, we propose a bandwidth-efficient channel coding scheme using the turbo trellis-coded modulation with multiple symbol detection. The turbo code can achieve good bit error rates (BER) at low SNR. That comprises two binary component codes and an interleaver. TCM codes combine modulation and coding by optimizing the euclidean distance between codewords. This can be decoded with the Viterbi or the symbol-by- symbol MAP algorithm. But we present the MAP algorithm with branch metrics of the Euclidean distance of the first phase difference as well as the Lth phase difference. The study shows that the turbo trellis-coded modulation with multiple symbol detection can improve the BER performance at the same SNR.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.1
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• pp.187-195
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• 1996

The purpose of this paper is to provide an algorithm in which the procedure of constructing a superstate transition matrix for trellis codes is reduced and, as a result, make it easier to evaluate the performance of a TCM scheme when the generalized transfer function method is used. In this paper, an algorithm for constructing a superstate transition matrix and an algorithm for reducing the matrix easily are addressed and applied to an MTCM scheme as an example. It is shown that the algorithm is very useflul for trellis codes with a large number of states and/or parallel transitions.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39A no.2
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• pp.86-91
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• 2014

Holographic data storage (HDS) has a number of advantages, including a high transmission rate through the use of a charge coupled device array for reading two-dimensional (2D) pixel image data, and a high density capacity. HDS also has disadvantages, including 2d intersymbol interference by neighboring pixels and interpage interference by multiple pages stored in the same holographic volume. These problems can be eliminated by modulation codes. We propose a 7/9 error-correcting modulation code that exploits a Viterbi-trellis algorithm and has a code rate larger (about 0.778) than that of the conventional 6/8 balanced modulation code. We show improved performance of the bit error rate with the proposed scheme compared to that of the simple 7/9 code without the trellis scheme and the 6/8 balanced modulation code.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.217-217
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• 2006

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.5 no.3 s.11
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• pp.29-39
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• 2006

In this paper, we propose an efficient method to detect the signal and evaluate performance of the system in frequency selective fading channel. We combine proposed system with OFDM (Orthogonal Frequency Division Multiplexing) to improve performance of the system. First, we study the SOSTTC-OFDM system using two transmit antenna and one receive antenna, and compare performance of the proposed space-time coded OFDM with that of previous system. We expand this system to the system using four transmit antennas with the proposed decoding method. Simulation results show that the proposed decoding method can detect the signal efficiently, and we identify that the performance of the proposed system is shown with varying doppler frequency in frequency selective fading channel.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.8C
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• pp.771-776
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• 2006

We present a suboptimum decoding method for space-time trellis codes, which include maximum $likelihood(ML)^{[1]}$ and principal ratio $combining(PRC)^{[2]}$, over quasi-static flat fading channels. In the proposed scheme, the receive antennas are divided into K groups and the PRC is applied to each group, showing a flexible performances between ML and PRC. When K is determined, we also propose the optimum grouping rules and performance index(PI), which simply anticipate the relative performances. Moreover the performances are also evaluated when receive antennas are correlated. Finally, Computer simulations corroborate those theoretical results.