• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.5 no.3 s.11
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• pp.13-23
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• 2006

The system using UWB is processing brisk study with Bluetooth among the wireless access that is major technology in Telematics. The low complexity and cost for realization is advantage of UWB have communication of high speed. Mamy papers have published on the timing jitter effect on system performance except for the UWB system. In this paper, we analyze the effect of timing jitter on M-ary UWB system using orthogonal Hermite pulse and perform the simulation to show symbol error rate performance. For theoretical analysis, we derive correlation function of orthogonal Hermits pulse with closed form, and as well upper bound of Symbol Error Probability for M-ary orthogonal Hermite pulse system mathematically. It is found that numerical analysis is accurate enough through simulation.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.4
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• pp.1-8
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• 2012

This paper presents a method for obtaining an exact average symbol error rate (ASER) of M-ary Phase Shift Keying (MPSK) for opportunistic amplify-and-forward (OAF) relay systems over Rayleigh fading channels. This is based on the relay selection probability when a relay is selected as the best one with respect to the received signal-to-noise ratio. We then derive the modified moment generating function (MGF) for OAF relay systems by taking the given relay selection probability into consideration. Based on the modified MGF, we derive the exact ASER which accurately explicates OAF relay system characteristics. Our results confirm that the derived ASER provides a tight upper bound for OAF relay systems.

• Journal of electromagnetic engineering and science
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• v.4 no.4
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• pp.175-182
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• 2004

When the M-ary signal experiences the Rayleigh fading, the diversity schemes can reduce the effect of fading since the probability that all the signals components will fade simultaneously is reduced considerably. The symbol error probabilities for various M-ary signals, such as MDPSK(M-ary DPSK) and MPSK(M-ary PSK), are mathematically derived for the Selection Combining 2(SC-2) and Selection Combining 3(SC-3) demodulation system which requires a less complex receiver than Maximum Ratio Combining(MRC). The propagation model used in this paper is the frequency-nonselective slow Rayleigh fading channel corrupted by the Additive White Gaussian Noise(AWGN). The numerical results presented in this paper are expected to provide information for the design of radio system using M-ary modulation method for above mentioned channel environment.

• Journal of electromagnetic engineering and science
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• v.4 no.4
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• pp.190-196
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• 2004

An alternative solution to the problem of obtaining acceptable performances on a fading channel is the diversity technique, which is widely used to combat the fading effects of time-variant channels. The symbol error probability of M-ary DPSK(MDPSK), PSK(MPSK) and QAM(MQAM) systems using 2 branches from the branch with the largest signal-to-noise ratio(SNR) at the output of L-branch selection combining(SC), i.e., SC2 in frequency- nonselective slow Nakagami fading channels with an additive white Gaussian noise(AWGN) is derived theoretically. These performance evaluations allow designers to determine M-ary modulation methods for Nakagami fading channels.

• Journal of electromagnetic engineering and science
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• v.7 no.1
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• pp.35-41
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• 2007

An alternative solution to the problem of obtaining acceptable performances on a fading channel is the diversity technique, which is widely used to combat the fading effects of time-variant channels. The symbol error probability of M-ary DPSK (MDPSK), PSK (MPSK) and QAM (MQAM) systems using 2 branches from the branch with the largest signal-to-noise ratio(SNR) at the output of L-branch selection combining(SC), i.e., SC2 in frequency-nonselective slow Nakagami fading channels with an additive white Gaussian noise(AWGN) is derived theoretically. These performance evaluations allow designers to determine M-ary modulation methods against Nakagami fading channels.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.42-45
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• 1998

Adaptive array antenas have emerged as a useful technique to enhance the cell capacity of mobile communications. In this research, to analyze the noncoherent CDMA systems employing adaptive array antennas, we modeled the transmitting signal of CDMA systems using M-ary orthogonal modulation. And we induced the conditional probability density function about the decision variable, the output of 2D-RAKE receiver and mean symbol error prabability through statistical analysis about MAI(Multiple Access Interference), SI(Self Interference) and Noise. Also, we analyzed the charateristics of adaptive array antenna for noncoherent CDMA systems using M-ary orthogonal modulation according to the distance between the array elements, doppler frequency and AOS(Angle of Spread).

• Journal of Communications and Networks
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• v.11 no.6
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• pp.564-573
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• 2009

In this paper, we consider a wireless multiple path network in which a transmitting node would like to send a message to the receiving node with a certain probability of success. These two nodes are separated by N erasure paths, and we devise two algorithms to determine minimum redundancy and optimal symbol allocation for this setup. We discuss the case with N = 3 and then extend the case to an arbitrary number of paths. One of the algorithms minimum redundancy algorithm in exponential time is shown to be optimal in several cases, but has exponential running time. The other algorithm, minimum redundancy algorithm in polynomial time, is sub-optimal but has polynomial worstcase running time. These algorithms are based off the theory of maximum-distance separable codes. We apply the MRAET algorithm on maximum-distance separable, Luby transform, and Raptor codes and compare their performance.

• ETRI Journal
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• v.34 no.4
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• pp.637-640
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• 2012

The Davey-MacKay construction is a promising concatenated coding scheme involving an outer $2^k$-ary code and an inner code of rate k/n, for insertion-deletion-substitution channels. Recently, a lookup table (LUT)-based inner decoder for this coding scheme was proposed to reduce the computational complexity of the inner decoder, albeit at the expense of a slight degradation in word error rate (WER) performance. In this letter, we show that negligible deterioration in WER performance can be achieved with an LUT as small as $7{\cdot}2^{k+n-1}$, but no smaller, when the probability of receiving less than n-1 or greater than n+1 bits corresponding to one outer code symbol is at least an order of magnitude smaller than the WER when no LUT is used.

• Journal of electromagnetic engineering and science
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• v.7 no.4
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• pp.183-189
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• 2007

When the M-ary signal experiences the Rayleigh fading, the diversity schemes can reduce the effect of fading since the probability that all the signals components will fade simultaneously is reduced considerably. The symbol error probabilities for various M-ary signals, such as MDPSK(M-ary DPSK) and MPSK(M-ary PSK), are mathematically derived for the Selection Combining 2(SC-2) and Selection Combining 3(SC-3) demodulation system which requires a less complex receiver than maximum ratio combining(MRC). The propagation model used in this paper is the frequency-nonselective slow Rayleigh fading channel corrupted by the additive white gaussian noise(AWGN). The numerical results presented in this paper are expected to provide information for the design of radio system using M-ary modulation method for above mentioned channel environment.

• Journal of electromagnetic engineering and science
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• v.7 no.4
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• pp.201-206
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• 2007

When the M-ary signal experiences the Rayleigh fading, the diversity schemes can reduce the effects of fading since the probability that all the signals components will fade simultaneously are reduced considerably. The symbol error probabilities for various M-ary signals, such as MDPSK, MPSK and MQAM, are mathematically derived for the SC-2(Selection Combining 2) demodulation system, whereby the two signals with the two largest amplitudes are coherently combined among the L branches. On the other hand, maximum ratio combining(MRC) requires the individual signals from each path to be time-aligned, cophased, optimally weighted by their own fading amplitude, and then summed. The propagation model used in this paper is the frequency-nonselective slow Rayleigh fading channel corrupted by the Additive White Gaussian Noise(AWGN). The numerical results presented in this paper are expected to provide information for the design of radio system using M-ary modulation method for above mentioned channel environment.