• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2009.10a
• /
• pp.112-115
• /
• 2009

PI code searching method of RDS(Radio Data System) are unique method of maintain desired channel on moving machine like vehicle. Efficient and fast PI code search method are researching on the all of RDS related systems for both find more better channel before Original channel signal go to bad and find desired good signal quickly when get out of Weak signal Area. But Embedded system has limited environment like memory size, so It is very difficult to apply many well known PI code searching method. This thesis suggests simple and effective method of searching PI code, considering a Embedded System Environment.

• Proceedings of the IEEK Conference
• /
• 2004.06a
• /
• pp.75-78
• /
• 2004

In this paper, we analyze the performance of transmitter and receiver of W-CDMA system using the channel coding and space time code in downlink over ITU-R realistic channel model. We can improve the data rate and the reliability of communications by a channel code, and we can get a diversity gain by using the space time code over fading channels. We also apply the RAKE receiver to improve a performance in multi-path fading channel environment.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.33 no.4C
• /
• pp.299-304
• /
• 2008

For perpendicular magnetic recording channels, it is hard to expect improving the performance by using the PRML or NPML. Hence, we exploit LDPC code to improve the performance. In this paper, we examine a single message-passing detector/decoder matched to the combination of a perpendicular magnetic recording channel detector and an LDPC code decoder. We examine the performance of channel iteration with joint LDPC code on perpendicular magnetic recording channel, and simplify the complexity of the message-passing detector algorithm.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.14 no.1
• /
• pp.1-6
• /
• 2021

In this paper, in order to mitigate ISI(inter-symbol interference) in a diffusion-based molecular communication channel, an ISI Hamming code is proposed in which ISI characteristics are applied to a channel decoding algorithm. In order to prove the bit error rate performance of the proposed channel code, the bit error rate performance of the major channel codes applied to the molecular communication channel with ISI was compared and analyzed through simulation. From the simulation results, it can be seen that the bit error rate performance of the ISI Hamming code is the best when the number of radiated molecules is less than or equal to 1100. In addition, when the number of transmitted molecules is M=1000, the decoding method of the ISI Hamming code proposed in this paper has improved the bit error rate of approximately 5.9×10-5 compared to the Hamming code using only soft values. Compared with the ISI-mitigating channel code, which is effective for removing ISI in the molecular communication channel, the ISI Hamming code proposed in this paper is the most advantageous in a channel environment where the number of transmitted molecules is not big (M<1100). And we can see that the ISI-mitigating channel code is more advantageous when the number of transmitted molecules is large(M>1100).

• Journal of Communications and Networks
• /
• v.7 no.3
• /
• pp.278-283
• /
• 2005

This paper proposes a blind channel estimation scheme for long code direct sequence code division multiple access (DS­CDMA) systems with multipath fading channels. This scheme combines the advantages of Toeplitz displacement and correlation matching methods to achieve improved performance. The basic idea is to remove the effects of noise and interferences with Toeplitz displacement operation and then estimate the multi path channel parameters with the correlation matching method. Simulation results are presented to show that the proposed scheme provides better MSE performance and robustness against the near-far problem.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.46 no.10
• /
• pp.14-27
• /
• 2009

Polar Code was proposed by Turkish professor Erdal Arikan in 2006 as an idea that splitted input channel is increasing the cutoff rate. The channel polarization consisted of code sequences with symmetric high rate capacity in a given B-DMC(Binary-input Discrete Memoryless Channel) W. The symmetric capacity is the highest rate achievable subject to using the input letters of the channel with equal probability. The channel polarization is said to a set of given N independent outputs of B-DMC W. In other word, N increases when N is a set of binary-input channels {$W^{(i)}_N\;:\;1{\leq}\;i\;{\leq}\;N$}, in I{WN(i)} as the fraction of indices is near to 1, which is approaching to I(W), and it is near to 0, then to 1-I(W), where I(W) presents high rates in reliable wireless communication channel as inputs of W with equal frequences. After all, {WN(i)} is shown to be a state of channel coding. On the based on this Polar codes, this paper analyzes Polar coding and decoding of Arikan and propose Radix4 Polar coding newly.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.29 no.7C
• /
• pp.921-930
• /
• 2004

In this paper, a robust video transmission system is proposed. To effectively prevent the corruption of video stream and its propagation in spatial and temporal domains, a version of turbo code, so-called as byte-aligned variable-length turbo code, is applied. Protection performance of the proposed turbo code is first evaluated by applying it to GOB-based variable-size ITU-T H.263+ video packets, where the protection level is statically controlled based on the joint source-channel criteria. This protection is then extended to support the adaptation of code ratio to best match the time-varying channel condition. The time-varying Rayleigh fading channel is modelled considering the correlation of the fading channel. The resulting performance comparison with the static turbo code as well as the conventional RCPC code clearly demonstrates the possibility of the proposed adaptation approach for the time-varying correlated Rayleigh-fading channel.

• ETRI Journal
• /
• v.32 no.4
• /
• pp.603-606
• /
• 2010

In this letter, we propose a channel estimation algorithm based on incremental pilots. These are pilots additionally inserted after puncturing the modulated orthogonal frequency division multiplexing (OFDM) symbols to enhance channel estimation performance without lowering bandwidth efficiency. A low-density parity-check code puncturing scheme is also proposed to prevent the performance degradation due to the codeword bit loss caused by punctured OFDM symbols.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.22 no.7
• /
• pp.1427-1436
• /
• 1997

Turbo codes, decoded through an iterative decoding algorithm, habe recently been shown to yidel remarkable coding gains close to theoretical limits in the Gaussian channel environment. This thesis presents the performance of Turbo code through the computer simulation. The performance of modified Turbo code is compared to that of the conventional Turbo codes. The modified Turbo code reduces the time delay in decoding with minimal effect to the performance for voice transmission sytems. To achieve the same performance, random interleaver the size of which is no less than the square root of the original one should be used. Also, the modified Turbo code is applied to MC-CDMA system, and its performance is analyzed under the Rayleigh Fading channel environment. In Rayleigh fading channel environment, due to the amplitude distortion caused by fading, the interleaver of the size twice no less than that in the Gaussian channel enironment was required. In overall, the modified Turbo code maintained the performance of the conventional Turbo code while the time delay in transmission and decoding was reduced at the rate of multiples of two times the squared root of the interleaver size.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.16 no.3
• /
• pp.73-80
• /
• 2016

We had introduced the backgrounds, history and physical meanings of Jong Nang in "Jeju Jong Nang Channel Code I, II and III". In "Jeju Jong Nang Channel Code II" paper, we have introduced practical the root of digital human binary coded Jong Nang communications as the wooden gate in Korea Jeju Island custom and investigated Jong Nang gatemodels as an approximation of the AWGN model. The objective was to find a deterministic model, which was accessible to analysis the capacity. Jong Nang communications mean the normal 3 rafters placed on two vertical stones with three holes to convey the family's whereabouts that is deterministic signal. In this paper we find the capacity of deterministic signal processing about the linear deterministic signals approximately.