• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.5
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• pp.409-412
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• 2004

This paper shows that the proposed Turbo TCM(Turbo Trellis Coded Modulation) has a good performance with a little complexity of decoder. The encoder structure, which is connected with Turbo Codes, is the proposed modulation technique for an efficient bandwidth, This method is used symbol by symbol MAP decoder of iteration similar to binary Turbo Codes in the receiver. The result shows that the BER performance according to iteration is improved about 2,5dB at $BER=10^{-2}$ compared to Turbo Codes with Gray mapping.

• Journal of the Institute of Convergence Signal Processing
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• v.4 no.4
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• pp.73-80
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• 2003

In this paper, we propose a ETD-turbo code(Enhanced Time Diversity turbo code) which is a novel turbo code configuration to increase the time diversity effect and analyze the performance of ETD-turbo coded MC-CDMA system. The ETD-turbo code, which is added another interleaver to the conventional turbo code structure, is consisted. Time diversity effect of the ETD-turbo code is improved by every parity bits converted into interleaver pattern. In order to the performance of the ETD-turbo code, we conduct a computer simulation about interleaver type. And we make comparison between the performance of ETD-turbo coded MC-CDMA system and the conventional turbo coded MC-CDMA system. By the simulation results, ETD-turbo code has less BER than the conventional turbo code and time delay is decreased by reducing iteration numbers. Therefore, it is defined that the performance of ETD-turbo coded MC-CDMA system is improved than the conventional turbo coded MC-CDMA system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.9C
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• pp.843-850
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• 2003

Turbo coding and turbo processing have been known as methods close to Shannon limit in the aspect of wireless MIMO communications similarly to wireless single antenna communication. The iterative processing can maximize the mutual effect of coding and interference cancellation, but turbo coding has not been used for turbo processing because of the inherent decoding process delay. This paper proposes a turbo coded MIMO system with adaptive turbo parallel space-time (Turbo-PAST) processing for high-speed wireless communications and a enhanced cyclic redundancy check (E-CRC) scheme as an efficient and simple priori stopping criterion. Simulation results show that the Turbo-PAST outperforms conventional system with 1.3dB and the proposed E-CRC scheme effectively reduces the amount of turbo processing iterations from the point of average number of iterations.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.8
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• pp.21-27
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• 2013

In this paper, we propose a low-complexity Turbo coded BICM-ID (bit-interleaved coded modulation with iterative decoding) system. A Turbo code is a powerful error correcting code with a BER (bit error rate) performance very close to the Shannon limit. In order to increase spectral efficiency of the Turbo code, a coded modulation combining Turbo code with high order modulation is used. The BER performance of Turbo-BICM can be improved by Turbo-BICM-ID using iterative demodulation and decoding algorithm. However, compared with Turbo-BICM, the decoding complexity of Turbo-BICM-ID is increased by exchanging information between decoder and demodulator. To reduce the decoding complexity of Turbo-BICM-ID, we propose a low-complexity Turbo-BICM-ID system. When compared with conventional Turbo-BICM-ID, the proposed scheme not only show similar BER performance but also reduce the decoding complexity.

• Proceedings of the IEEK Conference
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• 2001.06b
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• pp.297-300
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• 2001

Turbo code shows the great performance near Shannon limit on AWGN channel. Mainly, turbo code has been studied and designed for wireless digital communications. There are recent studies that applies turbo decoder on magnetic recording. Because of the limited capacity of magnetic storages, high rate turbo code is used for magnetic storages. This paper presents some issues on implementing high rate turbo code and structures for designing turbo decoder

• Proceedings of the IEEK Conference
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• 2000.11b
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• pp.277-280
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• 2000

In this paper, we designed a turbo decoder using VHDL. To maximize effective free distance of the turbo code, we implemented pseudo random interleaver. A MAP(Maximum a posteriori) decoder is used as a primimary decoder. We avoided multiplication by using lookup tables(ROM). We expect that this small-sized turbo decoder is suitable for mobile communication. We simulated turbo decoder with Altera MAX+PLUS II.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.2C
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• pp.181-186
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• 2004

Recently, there has been intensive focus on Turbo Product Codes(TPCs) which have low decoding complexity and achieve near-optimum performances at high code-rate. This paper present a parallel algorithm of turbo product codes enable simultaneous decoding of row and column. The row and column decoders operate in parallel and update each other after row and column has been decoded. simulation results show that the performance of proposed parallel turbo code is almost the same as that conventional scheme for several turbo product codes.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.7
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• pp.1525-1530
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• 2015

In this paper, We analyzed the performance of turbo equalizer using turbo codes thorough the under water experiment. To compensate the distorted signal induced by multipath effect, we apply the iterative turbo codes that iteratively exchange probabilistic information between LMS-DFE and turbo decoder, thereby reducing the error rates significantly. We showed the successful of turbo decoding of iterative turbo equalizer is 93%.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.2
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• pp.279-285
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• 2011

The next generation wireless communication systems are required high BER performance better than present performance. Double binary Turbo code have error floor at high SNR, so it cannot be used in next generation wireless communication system. Therefore, many methods are proposed for overcome error floor at DVB-RCS NG(next generation). In this paper, we analysis structure of third-dimension Turbo code(3D-turbo code). 3D-Turbo code overcomes error flow by additive post-encoder in conventional DVB-RCS Turbo code. Performance of 3D-Turbo code is changed by post-encoder form, interleaving method, value of ${\lambda}$. So we are simulated by those parameter and proposed optimal form. By a result, performance of 3D-Turbo is better than conventional DVB-RCS Turbo code and it overcome error floor of conventional DVB-RCS Turbo code.

• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.157-160
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• 2006

A turbo-expander is developed for the regeneration in the expansion process. The turbo-expander operates in the partial admission and supersonic flow, and an axial-type single stage turbine is applied to the turbo-expander. Its outer diameter is 82mm and the operating gas is R134a. A 15kW reciprocating compressor is applied in this experiment and the turbo-expander is installed in the expansion process instead of the commonly using expansion valve. Two supersonic nozzles are applied for the expansion process. The high speed of R 134a after passing the supersonic nozzles gives the impulse force to the turbo-expander and some powers are generated on this process. A generator is installed at the end of the turbo-expander shaft. The generating output power from the turbo-expander is controlled by the power controller. Pressures and temperatures are measured on the lines for the performance investigation. More than 600W/(kg/sec) are generated in this experiment.