• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.3
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• pp.218-223
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• 2016

This study examined the order of the Butterworth filter for the correlation on the sensitivity of the receiver in the receiver of an optical system. In the general case, the sensitivity of the receiver is increased if the order of the filter was increased more. This is because increasing the order of the filter response of the normalized frequency of the filter is similar to the rectangular wave. For that reason, the method used to increase the order of the filter increases the sensitivity of the receiver. On the other hand, a method of increasing the order of the filter and makes the system complicated increases the cost of the system. This study examined the correlation between the order of the sensitivity of the receiver filter and to configure the system by simply looking for ways to reduce the cost of the system. The simulation results showed that increasing the order of the filter resulted in a receiver that can determine if the sensitivity is raised. In addition, the order of the Butterworth filter range that does not reduce the sensitivity of the receiver was 2. Therefore, it will be possible to implement an inexpensive optical system of the receiver using the data from this study.

• Journal of the Korea Convergence Society
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• v.9 no.8
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• pp.33-39
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• 2018

In the Internet of Things (IoT) era, objects are connected to each other by wired and wireless networks, and information is exchanged whenever necessary. Channel and network environments change over time; thus, a carrier sensing function that identifies whether signals containing information are present in the channel is essential. The carrier sensing circuit of a wireless communication system determines the receiver sensitivity, and the receiver sensitivity is closely related to the service coverage and service quality of the system. As the receiver sensitivity decreases, the service coverage increases but it becomes sensitive to noise. However, as the receiver sensitivity increases, the service coverage decreases but it becomes insensitive to the noise. Therefore, carrier sensing design and optimization are very important from the viewpoint of the receiver sensitivity and noise sensitivity. This paper proposes an effective carrier sensing technique from the viewpoint of the receiver sensitivity for the long range IoT.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.5
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• pp.2272-2278
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• 2011

It is essential to various evaluate about statistic character of the signal and additional noise for optimization of the optical communication system. We expressed various error probability with the m which was bandwidth and a bit numerical function and carried out performance evaluation of a PIN receiver. This research analyzed the receiving sensitivity of the PIN receiver and verified reception sensitivity through computer simulation in the optical communication system. As a result, the receiving sensitivity for PIN receiver are $9.2{\times}10^4$ photon/bit for given error probability.

• 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.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.1
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• pp.108-111
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• 2016

We propose the method for measuring sensitivity of optical receiver of a long-range laser range finder in real-time. The sensitivity of the detector can be calculated using the detected voltage of the reference sensor, the area of the reference sensor and the transmittance ratio of neutral density filters. To evaluate the performance of the proposed method, we implemented a system and performed experiments. As a result, this system can be measured from 2nW to $113{\mu}W$. With this system, we measured the sensitivity of 37nW and 7nW with PIN PD and APD sample, respectively. This system has the advantage for the performance test of an optical sensor module in the long-range laser range finder.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.198-202
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• 2003

An engineer prefers DIFM receiver which is superior to instantaneous response rather than superheterodyne receiver which has a scan rate in normal wide band receiver designing. But DIFM receiver has weak point in sensitivity and continuous wave signal because of special environments. In this paper we propose the method which is certificated through simulation and prototype testing to improve sensitivity of DIFM receiver. And we analyze the important factors of DIFM receiver from our results.

• Korean Journal of Optics and Photonics
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• v.31 no.6
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• pp.259-267
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• 2020

We evaluate the degradation of receiver sensitivity induced by direct and indirect exposure to solar irradiance in free-space optical communication systems. For this purpose, we calculate the variances of numerous noise components arising from solar irradiance, and then estimate the receiver sensitivity penalties for intensity-modulation/direct-detection and coherent systems. The results show that the penalties are less than 1.3 dB when indirect sunlight impinges on the detector, regardless of the system. However, the sensitivity penalties are estimated to be larger than 30 dB when the sunlight is directly incident upon the receiver. These penalties are barely reduced if we insert an optical polarizer, or if we adjust the bandwidth of an optical filter at the receiver to be as narrow as the signal's bandwidth.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.3
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• pp.579-585
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• 2006

In this study, we analysis an optical receivers using the optical preamplifier in a spectrum-sliced WDM systems. The average numbers of photons/bit, for an $10^{-9}$ error probability, counts using the OOK and FSK transmission. As a result, the theoretical sensitivity for PIN receiver and optical preamplifier receiver are approximately $9.2\times10^4\;and\;7.2\times10^2$ in the m=20, respectively. Also, the average numbers of photons/bit, for and given error probability, theoretical receiver sensitivity for Gaussian method and k-square method are approximately $9\times10^2\;and\;2.16\times10^2$ in the m=40, respectively. And the average numbers of photons/bit, for an given error probability, theoretical receiver sensitivity, OOK and FSK transmission are approximately $1.9\times10^2\;and\;3.1\times10^2$ in the m=20, respectively.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.8
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• pp.9-16
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• 2007

Currently, the measurement of RF parameters for a base station in operation is typically limited to easily measured forward path items. In this paper, the forward monitoring ports of base stations are used to measure the reverse RF performance. The system has been implemented and effectiveness has been proven on an operating base station. The receiver sensitivity is measured using an internal CDMA modem which is used to monitor the output power based on closed loop power control when the modem is connected to the base station via a voice call. In order to improve accuracy, in addition to the modem Tx adjust(TxAdj) parameter, the detector's actual measurement is used. For accurate receiver sensitivity, the measurement should be made when there is no traffic which is not possible on an operating base station. Therefore, pilot channel chip energy to received signal power spectral density ratio$(E_c/I_o)$ compensation method is used to offset the receiver sensitivity degradation with voice traffic increase.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.6
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• pp.507-513
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• 2002

In this paper, the receiver using Heterodyne type is designed and implemented for a pulse radar at 9.4 GHz. The If amplifier, which occupies a significant size in a Heterodyne receiver for pulse radars, can be removed. Furthermore, by using detector logarithmic video amplifier in baseband, the receiver has a small size and it's characteristic shows a high dynamic range and sensitivity. From the results of measurements, the minimum receiver power of -70 dBm and selectivity of 55 dB are obtained.