• Proceedings of the IEEK Conference
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• 2004.06a
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• pp.39-42
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• 2004

Turbo codes, proposed by Berrou, that increase the interleaver size and the number of iteration have better than conventional convolutional codes, in case of BER performance. However, because turbo codes has been required much decoding delay to increase iteration number, it demands unnecessary iterative decoding. Therefore, in this paper, we propose iterative decoding stop criterion that uses the variance of absolute value of LLR. This algorithm can be reduced average iterative decoding number and had lossless performance of BER, because of decreasing unnecessary iterative decoding.

• The Transactions of the Korea Information Processing Society
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• v.7 no.6
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• pp.1923-1931
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• 2000

In this paper, e analyze the performance of the PSS-type Viterbi decoder which can reduce calculations and power consumption using the Monte Carlo simulations. Gaussian and burst noise channels are considered in this simulation, and we achieve that convolutional interleaver can reduce complexity and power consumption in burst noise channel. In order to implement the high-speed PSS-type Viterbi decoder, the architectures of decoder are presented, and we implemented the PSS-type Viterbi decoder for r=1/2, k=3 using the VHDL tool, and prove the decoding process.

• Proceedings of the KIEE Conference
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• 2000.11a
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• pp.211-213
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• 2000

This paper represent powerline communication system for data transmission. Powerline communication model is the Local Area Network which length is 250m in SKKU. Simulation is applied DS-CDMA. Convolutional coding, Viterbi decoding and Interleaver. Simulation result say that proposed system is superior performance and available in present.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.83-86
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• 1999

In this paper, a serially concatenated space-time code (SCSTC) with bandwidth efficiency and high data rate is studied. The suggested SCSTC is composed of space-time code, the convolutional code and Interleaver. The SCSTC has a very high BER performance than the conventional space-time code. The BER performance of the suggested SCSTC can be proven by using computer simulation through the iterative decoding method. The first decoder uses Symbol-MAP algorithm and the second decoder uses Bit-MAP algorithm for decoding tile information bits. The simulation results show the performance of the suggested SCSTC is better than the conventional Space-Time Code.

• Journal of Advanced Navigation Technology
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• v.15 no.2
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• pp.221-226
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• 2011

This paper presents a DTMB deinterleaver structure to reduce SDRAM power consumption. DTMB, the Chinese digital TV standard, has a deinterleaver that consists of many long delay buffers. SDRAM is used for this deinterleaver. The proposed structure pairs data and transfer a pair with an SDRAM transfer. With the reduction of the SDRAM operation number, the proposed structure can save the SDRAM power consumption by around 35%.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.5
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• pp.738-745
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• 2009

Underwater acoustic communication has multipath error because of reflection by sea-level and sea-bottom. The multipath of underwater channel causes receive signal to make error floor. In this paper, we propose the underwater communication system using various channel coding schemes such as RS coding, convolutional code, turbo code and concatenated code for overcoming the multipath effect in underwater channel. As shown in simulation results, characteristic of multipath error is similar to that of random error. So interleaver has not effect on error correcting. For correcting of error floor by multipath, it is necessary to use strong channel codes like turbo code. Turbo code is one of the iterative codes. And the performance of concatenated codes including RS code has better performance than using singular channel codes.

• Journal of Industrial Technology
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• v.18
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• pp.431-437
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• 1998

In this paper, we presented a modeling of the power line channel and a new digital communication system over the channel. Firstly, we proposed a new tranceiver structure with DS-CDMA spread spectrum technique and convolutional coder and block interleaver against severe noisy power line environment. Also, QPSK modulation technique was used to get bandwidth efficiency. And then we performed a simulative evaluation of the system using MATLAB communication/simulink toolbox. According to the simulation results, the proposed system gives $10^{-6}$ BER at 20dB SNR.

• The KIPS Transactions:PartA
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• v.11A no.1
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• pp.81-88
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• 2004

In this paper, we designed the outer encoder/decoder for the terrestrial DMB that is an advanced digital broadcasting standard, implemented, and verified by using ALTERA FPGA. In the encoder part, it was created the parity bytes (16 bytes) from the input packet (188by1e) of MPEG-2 TS and the encoded data was distributed output by the convolutional interleaver for Preventing burst errors. In the decoder part, It was proposed the algorithm that detects synchronous character suitable to DMB in transmitted data from the encoder. The circuit complexity in RS decoder was reduced by applying a modified Euclid's algorithm. This system has a capability to correct error of the maximum 8 bytes in a packet. After the outer encoder/decoder algorithm was verified by using C language, described in VHDL and implemented in the ALTERA FPGA chips.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.7
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• pp.13-23
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• 2009

In this paper, the network performance of a turbo coded optical code division multiple access (CDMA) system with cross-layer, which is between physical and network layers, concept is analyzed and simulated. We consider physical and MAC layers in a cross-layer concept. An intensity-modulated/direct-detection (IM/DD) optical system employing pulse position modulation (PPM) is considered. In order to increase the system performance, turbo codes composed of parallel concatenated convolutional codes (PCCCs) is utilized. The network performance is evaluated in terms of bit error probability (BEP). From the simulation results, it is demonstrated that turbo coding offers considerable coding gain with reasonable encoding and decoding complexity. Also, it is confirmed that the performance of such an optical CDMA network can be substantially improved by increasing e interleaver length and e number of iterations in e decoding process. The results of this paper can be applied to implement the indoor optical wireless LANs.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.4A
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• pp.519-527
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• 2000

This paper suggests and analyzes the Serially Concatenated Space-Time Code(SCSTC) with the possibility of a efficient high-speed transmission in a band limited channel. The suggested code has a structure that uses the interleaver to connect the space-time code as an inner code and the convolutional code as a outer code serially. This code keeps the advantage of high-speed transmission and also has the high BER performance. The performance of the suggested system is compared with the conventional bandwidth efficient trellis coded modulation, such as a Serially Concatenated Trellis Coded Modulation (SCTCM) and a Turbo-Trellis Coded Modulation(Turbo-TCM). The results show that the suggested system has a 2.8dB and 3dB better BER performance than SCTCM and Turbo-TCM respectively in case of the transmission rate 2b/s/Hz in fading channel.