• Proceedings of the Korea Society of Information Technology Applications Conference
• /
• 2005.11a
• /
• pp.69-72
• /
• 2005

As life style becomes to be complicated, lots of support technologies were developed. The bar code technology is one of them. It was renovating approach to goods industry. However, data storage ability in one dimension bar code came in limit because of industry growth. Two-dimension bar code was proposed to overcome one-dimension bar code. PDF417 bar code most commonly used in standard two-dimension bar codes is well defined at data decoding and error correction area. More works could be done in bar code image acquisition process. Applying various image enhancement algorithms, the recognition rate of PDF417 bar code is improved.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.60 no.5
• /
• pp.1036-1042
• /
• 2011

This paper presents an algorithm that conducts automatic memory scrubbing operated by dedicated hardwares. The proposed algorithm is designed so that it can scrub entire memory in a given scrub period, while minimally affecting the execution of flight softwares. The scrub controller is constructed in a form of state machines, which have two execution modes - normal mode and burst mode. The deadline event generator and period tick generator are designed in a separate way to support the behavior of the scrub controller. The proposed controller is implemented in VHDL code to validate its applicability. A simple version of the controller is also applied to mass memory modules used in STSAT-3.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.22 no.7
• /
• pp.1477-1486
• /
• 1997

Conventioally the decoding methods and the design of coset codes for burst synchronization and error detection have been based on the concept that slips occuring to the right or to the left with respect to a reference timing are corrected. In this paper we newly approach to the design of coset codes relying on the condition that only a single code word can exists in an observation interval, which provides an extentended view on the conventional approach. A theorem concerning the condition is presented. A combined burst synchronization and error detection system with maximum slip correction capability have been devised based on the theorem and a detection method is falsely accepted in the presented of channel errors. The false acceptance probabilities of the system are derived and its performance is analyzed through computer computation using the derived results.

• Journal of Semiconductor Engineering
• /
• v.1 no.2
• /
• pp.74-80
• /
• 2020

Due to its superior error correcting performance with affordable hardware complexity, the Polar code becomes one of the most important error correction codes (ECCs) and now intensively examined to check its applicability in various fields. However, Successive Cancellation (SC) decoding that brings the advanced Successive Cancellation List (SCL) decoding suffers from the long latency due to the nature of serial processing limiting the practical implementation. To mitigate this problem, many decoding architectures, mainly divided into pruning and parallel decoding, are presented in previous manuscripts. In this paper, we compare the recent SC decoding architectures and analyze them using a tree structure.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.17 no.7
• /
• pp.730-738
• /
• 1992

This paper alms to analyse the performance of frequency hopping /spread spectrum multiple access system by employing the channel with mixture of AWGN, partial band Jamming, fading and user interference. The performance analysis of FH /SSMA system, taking account of frequency 'hit'(user Interference ) which occurs in the presence of multiple user, produces the following numerical results by computing error probability and throughput of each code in two cases whether the side Information about channel is used or not. The numerical results are as follows : When composite interferences coexist In channel, RS code Is significantly superior to convolutional code in terms of performance. Concatenated code provides the same performance as RS code. The above results show that RS code is pertinent as error-correction code.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.50 no.8
• /
• pp.21-27
• /
• 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
• /
• 2001.06a
• /
• pp.113-116
• /
• 2001

Reed-Solomon(RS) code is the most powerful burst error correcting code. In Ois paper, the architecture for the adaptive RS encoder adaptable for multi QoS requirements or time-varying channel environments has been designed. In the adaptive RS code, the message length k and the error correction capability t are allowed to be variable so that the block length n is also variable. We proposed the architecture of the adaptive RS encoder by designing the optimal structure of Galois fields multiplier with comparison of fixed multiplier and variable multiplier. The proposed architecture is implemented in VHDL and verified with the simulation tool

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.14 no.3
• /
• pp.216-226
• /
• 1989

In this paper, we explain about an outline of the decoding method for double encoding system using the error correcting capacitance and a simple decoding method. We have been taken formation two-dimension code word of doubly-encoded code using $C_1$(32, 28, 5) and $C_2$(32, 26, 7) Reed-Solomon codes, and had computer simulation of the erroe correcting processes in frequency domain. On these processes, the newly developed digital signal processing technology such as error correction using Berlekamp-Massey algorithm in frequency domain have been proven.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.27 no.4
• /
• pp.491-501
• /
• 1990

Recently, four speech coding techniques, namely, SBC-APCM(sub-band coding adaptive PCM), RPE-LPC(regualr pulse excitation linear predictive codec), MPE-LTP(multi-pulse excited long-term prediction) and CELP (code-excited linear prediction) are proposed for digital mobile radio applications. However, a performance comparison of these coders in the Rayleigh fading environment has not been made yet. In this paper, the performances of the four spech coders in the random bit error and burst error environment are investigated. For the channel coding of SBC-APCM, RPE-LPC and MPE-LTP, the sensitivity of output bit stream is measured and a bit selective forward error correction is provided acording to the measured bit sensitivity. And for an attempt to improve the performance of CELP, an optimum quantizer is applied for transmitting scalar quantities in CELP. However, an improvement over the conventional approach is found to be negligible. For the channel coding of CELP, Reed-Solomon code, Golay code, convolutional code of rate 1/2 shows the best performance. Finally, from the simulation results, it is concluded that CELP is the best candidate for digital mobile radio and is followed by MPE-LTP, SBC-APCM and RPE-LPC.

• Journal of the Semiconductor & Display Technology
• /
• v.22 no.1
• /
• pp.43-48
• /
• 2023

This paper discusses the design of 32Mbyte asynchronous nonvolatile memory modules, which includes self-diagnosis and RTC (Real Time Clock) functions to enhance their data stability and reliability. Nonvolatile memory modules can maintain data even in a power-off state, thereby improving the stability and reliability of a system or device. However, due to the possibility of data error due to electrical or physical reasons, additional data loss prevention methods are required. To minimize data error in asynchronous nonvolatile memory modules, this paper proposes the use of voltage monitoring circuits, self-diagnosis, BBT (Bad Block Table), ECC (Error Correction Code), CRC (Cyclic Redundancy Check)32, and data check sum, data recording method using RTC. Prototypes have been produced to confirm correct operation and suggest the possibility of commercialization.