• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.7 no.2
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• pp.86-91
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• 2014

This paper compare with SNR performance of coherent integration and non-coherent integration in radar system. This paper to prevent distortion of transmit signal and radar return in radar system is used to pulsed waveform. This paper to estimate target detection range and to compare with SNR performance used to coherent integration performed before the envelope detector and non-coherent integration processed after the envelope detector. Through simulation, SNR performance of coherent integration and non-coherent integration were comparatively analyzed. SNR performance of coherent integration is good proof higher than non-coherent integration.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1988.10a
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• pp.223-226
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• 1988

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.3
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• pp.304-306
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• 2016

In this letter, we investigate the performance of coherent free-space optical(FSO) systems under pulsed noise jamming conditions. In particular, we derive the average bit error probability of the coherent FSO systems with the pulsed noise jamming in a closed-form. Also, we derive the optimal fraction of symbol time of the jammer. We confirm the derived average error probability expressions by the exactly matching Monte-Carlo simulation results.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.6
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• pp.107-112
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• 2014

In this paper, we analysed a performance signal to noise ratio about pulse, integration coherent, and integration non coherent system in radar system. It compared existing with proposal method in order to estimation two target direction of arrival. Generally, radar system radiate pulse wave in order to decreasing distortion of return wave and transmission wave. We analysed the performance integration coherent and integration non coherent. Integration coherent is processing system before doing envelop detection, and integration non coherent is processing system after doing envelop detection. Through simulation, we analysed a performance signal to noise ratio to estimation two target range detection and estimated target direction of arrival. We showed that integration coherent system is the most good performance.

• Journal of Broadcast Engineering
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• v.25 no.6
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• pp.870-881
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• 2020

This paper presents cell ID (cell identity) detection schemes using PSS/SSS (primary synchronization signal/secondary synchronization signal) for 5G NR (new radio) system and evaluates the detection performance. In this paper, we consider two cell ID detection schemes, i.e. two-stage detection and joint detection schemes. The two-stage detection scheme consists of two stages which estimate a channel gain between a transmitter and receiver and detect the PSS and SSS sequences. The joint detection scheme jointly detects the PSS and SSS sequences. In addition, this paper presents coherent and non-coherent combining schemes. The coherent scheme calculates the correlation value for the total length of the given PSS and SSS sequences, and the non-coherent combining scheme calculates the correlation within each group by dividing the total length of the sequence into several groups and then combines them non-coherently. For the detection schemes considered in this paper, the detection error rates of PSS, SSS and overall cell ID are evaluated and compared through computer simulations. The simulation results show that the joint detection scheme outperforms the two-stage detection scheme for both coherent and non-coherent combining schemes, but the two-stage detection scheme can greatly reduce the computational complexity compared to the joint detection scheme. In addition, the non-coherent combining detection scheme shows better performance under the additive white Gaussian noise (AWGN), fixed, and mobile environments.

• 한국정보통신설비학회:학술대회논문집
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• 2006.08a
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• pp.235-240
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• 2006

In order to enhance receive sensitivity in noisy environment, the previous initial synchronization method of GPS receiver for reference stations adopts not only the coherent integration method but also the non-coherent integration method. However, the previous GPS initial synchronization method causes the non-coherent integration loss, which is a dominant factor among the signal acquisition losses in noisy environment. And the non-coherent integration loss increases with the strength of noise signal. In this pa-per, a GPS initial synchronization method is proposed to enhance receive sensitivity of GPS receiver for reference stations in noisy environment. This paper presents that the proposed GPS initial synchronization method suppresses the non-coherent integration loss. Furthermore, with regard to the mean acquisition time, it is shown that the number of the search cells of the proposed GPS initial synchronization method is much fewer than that of the previous GPS initial synchronization method.

• Journal of Communications and Networks
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• v.14 no.5
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• pp.518-523
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• 2012

This paper presents new coherent and non-coherent detection methods for the IEEE 802.15.4a low-rate ultra-wideband physical layer with forward error correction (FEC) coding techniques. The coherent detection method involving channel estimation is based on the correlation characteristics of the preamble signal. A coherent receiver uses novel iterated selective-rake (IT-SRAKE) to detect 2-bit data in a non-line-of-sight channel. The non-coherent detection method that does not involve channel estimation employs a 2-bit data detection scheme using modified transmitted reference pulse cluster (M-TRPC) methods. To compare the two schemes, we have designed an IT-SRAKE receiver and a MTRPC receiver using an IEEE 802.15.4a physical layer. Simulation results show the performance of IT-SRAKE is better than that of the M-TRPC by 3-9 dB.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.12A
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• pp.1145-1151
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• 2010

Hochwald et al. introduced unitary space-time codes for quasi-static Rayleigh fading channels which allows for noncoherent decoding when the channel response is not known at the receiver. However, when reliable information on the channel response is available, coherent decoding is preferable for improved performance. Here, we study the relationship between the performance criteria on the diversity and coding advantages provided by unitary space-time codes with noncoherent and coherent decoding. We show that when a unitary space-time code achieves full spatial diversity with noncoherent decoding, full spatial diversity is also guaranteed with coherent decoding.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.6B
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• pp.625-637
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• 2002

This study extends the modified linear feedback equalizer (MLFE), normally used for differentially coherent DPSK systems, to the equalization of double differentially coherent PSK (DDPSK) signals. By feeding back into the feedback part after modifying the equalizer output using decision feedback-based demodulation, the proposed equalizer can operate like an equalizer with a decision feedback structure. Simulation results showthat performances of the decision feedback demodulation-based feedback equalizer (DFD-FE) approach those of the DFE/coherent.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.3
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• pp.515-523
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• 1997

A high resolution algorithm is presented for resolving multiple coherent spread spectrum signals that are incident on an equispaced linear array. Unlike the conventional noise-eigenvector based methods, this algorithm makes use of the signal eigenvectors of the array spectral density matrix that are associates with eigenvalues that are larger than the sensor noise level. Simulation results are shown to demonstate the high performance of the proposed approach in comparison with MUSIC in which coherent signal subspace method (CSM) is employed.