• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.7A
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• pp.503-511
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• 2012

In this paper, the performance analysis of telemetering method using delayed frame time diversity (DFTD) as the outer code and Reed-Solomon (RS) code as the inner code is described. DFTD is used to transmit a real-time frame together with a time-delayed frame which was saved in the memory during a defined period. The RS code as a kind of FEC (forward error correction) is serially concatenated with DFTD. This method was applied to the design of telemetry units that have been used for flight tests in a communication environment with deep fading. The data of the flight test for four cases with no applied code, with DFTD only, with the RS code only, and with both DFTD and the RS code are used to analyze the performance. The simulation for time-delay suggests the possibility that all frame errors can be removed. And the results of 12 flight tests show the performance superiority of this new method to compare with the RS code only.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.7
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• pp.140-148
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• 2013

This paper presents a iterative Bose-Chaudhuri-hocquenghem (i-BCH) code and its high-speed decoder architecture for 100 Gb/s optical communications. The proposed architecture features a very high data processing rate as well as excellent error correction capability. The proposed 6-iteration i-BCH code structure with interleaving method allows the decoder to achieve 9.34 dB net coding gain performance at $10^{-15}$ decoder output bit error rate to compensate for serious transmission quality degradation. The proposed high-speed i-BCH decoder architecture is synthesized using a 90-nm CMOS technology. It can operate at a clock frequency of 430 MHz and achieve a data processing rate of 100 Gb/s. Thus, it has potential applications in next generation forward error correction (FEC) schemes for 100 Gb/s optical communications.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.162-164
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• 2010

Terrestrial trunked radio (TETRA) standard specifies shortened Reed-Muller (RM) codes as forward error correction means for control signals. In this paper, we compare decoding algorithms for RM codes in TETRA, in terms of performance and complexity trade-off. Belief propagation and majority logic decoding algorithms are selected for comparison.

• JSTS:Journal of Semiconductor Technology and Science
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• v.13 no.5
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• pp.465-472
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• 2013

This paper presents a low-complexity triple-error-correcting parallel Bose-Chaudhuri-Hocquenghem (BCH) decoder architecture and its efficient design techniques. A novel modified step-by-step (m-SBS) decoding algorithm, which significantly reduces computational complexity, is proposed for the parallel BCH decoder. In addition, a determinant calculator and a error locator are proposed to reduce hardware complexity. Specifically, a sharing syndrome factor calculator and a self-error detection scheme are proposed. The multi-channel multi-parallel BCH decoder using the proposed m-SBS algorithm and design techniques have considerably less hardware complexity and latency than those using a conventional algorithms. For a 16-channel 4-parallel (1020, 990) BCH decoder over GF($2^{12}$), the proposed design can lead to a reduction in complexity of at least 23 % compared to conventional architecttures.

• Korean Journal of Optics and Photonics
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• v.33 no.3
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• pp.106-112
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• 2022

A two-dimensional optical code division multiple access (OCDMA) encoder/decoder, which is composed of add/drop filters and all-pass filters for delay operation, is proposed. An example design is presented, and its feasibility is illustrated through numerical simulations. The chip area of the proposed OCDMA encoder/decoder could be about one-third that of a previous OCDMA device employing delay waveguides. Its performance is numerically investigated using the transfer-matrix method combined with the fast Fourier transform. The autocorrelation peak level over the maximum cross-correlation level for incorrect wavelength hopping and spectral phase code combinations is greater than 3 at the center of the correctly decoded pulse, which assures a bit error rate lower than 10^-3, corresponding to the forward error-correction limit.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.4
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• pp.299-302
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• 2002

Error detection and correction using CRC and the general class of cyclic codes is an important part of designing reliable data transmission schemes. The decoding method for cyclic codes using covering patterns is easily-implementable, and its complexity de-pends on the number of covering patterns employed. Determination of the minimal set of covering patterns for a given code is an open problem. In this paper, an efficient search method for constructing minimal sets of covering patterns is proposed and compared with several existing search methods. The result is applicable to various codes of practical interest.

• Journal of Internet Computing and Services
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• v.23 no.3
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• pp.1-12
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• 2022

As the performance of Unmanned Aerial Vehicles (UAVs) are improving and the prices are lowering, it is expected that the use of UAVs will continuously grow in the future. It is important to always maintain control signal and video communication to operate remote UAVs stably, especially in military UAV operations, as unexpected jamming attacks can result in fatal UAV crashes. In this paper, to improve the network reliability and low latency when supporting UAV operations, the anti-jamming performance of Second generation Anti-jam Tactical UHF Radio for NATO (SATURN) networks is analyzed and enhanced by applying Forward Error Correction (FEC) and Minimum Shift Keying (MSK) modulation as well as Hamming code based multiple transmission techniques.

• Journal of Advanced Navigation Technology
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• v.11 no.2
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• pp.170-176
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• 2007

In this paper, we improve performance for system when the carrier recovery signal is not perfect in the multipath mobile wireless communication fast fading channel based on DS-CDMA system. In the case, we use the phase estimation, diversity and adaptive FEC code technique in order to overcome this carrier phase error and mobile wireless fading. As a results in DS-CDMA system, we know that the appropriate use of diversity and adaptive FEC code technique reduced considerably performance degradation due to phase error.

• Journal of Korea Multimedia Society
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• v.6 no.7
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• pp.1239-1244
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• 2003

In this paper, we analyzed cell loss rate performance for random traffic sources in wireless ATM(Asynchronous Transfer Mode) access architecture, which consists of access node and wireless channel. Applying queueing model to cell level at access node and considering burst error characteristics in wireless channel, we derived a formula about the cell loss rate of the random traffic in the wireless ATM access architecture. We also applied FEC(Forward Error Correction) schemes to improve the cell loss rate of random traffic. When we applied FEC schemes in the wireless ATM access architecture, we confirmed that the concatenated code provides the most superior performance compared to any other codes.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.7
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• pp.43-51
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• 2013

This paper describes the development of the telemetry link system for the high data rate transmission in high speed rocket application. In consideration of bandwidth efficiency, frequency selective fading and doppler frequency offset, we used DQPSK instead of PCM/FM which has been the primary modulation format in aeronautical telemetry. Also we used the spatial diversity with multiple receiving antennas to mitigate multipath interference which is the dominant channel impairment and the Turbo Product Code for Forward Error Correction to improve bit error rate performance.