• Journal of Convergence for Information Technology
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• v.11 no.8
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• pp.29-35
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• 2021

Since a sufficient condition on the larger rate volume of 3-user correlated information sources (CIS)/non-successive interference cancellation (SIC) non-orthogonal multiple access (NOMA) over independent information sources (IIS)/SIC NOMA has not been investigated, this paper analyzes such a sufficient condition. First, we demonstrates that the rate volume of 3-user CIS/SIC NOMA is the same as a portion of the rate volume of 3-user IIS/SIC NOMA. Then, by identifying a dominant rate region, we calculate the sufficient condition on the larger rate volume of 3-user CIS/non-SIC NOMA over 3-user IIS/SIC NOMA. We also show that with such condition, the rate volume of 3-user CIS/non-SIC NOMA can be larger than that of 3-user IIS/SIC NOMA.

• International journal of advanced smart convergence
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• v.10 no.2
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• pp.1-9
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• 2021

In the Internet-of-Things (IoT) and artificial intelligence (AI), complete implementations are dependent largely on the speed of the fifth generation (5G) networks. However, successive interference cancellation (SIC) in non-orthogonal multiple access (NOMA) of the 5G mobile networks can be still decoding latency and receiver complexity in the conventional SIC NOMA scheme. Thus, in order to reduce latency and complexity of inherent SIC in conventional SIC NOMA schemes, we propose a rate-lossless non-SIC NOMA scheme. First, we derive the closed-form expression for the achievable data rate of the asymmetric 2PAM non-SIC NOMA, i.e., without SIC. Second, the exact achievable power allocation interval of this rate-lossless non-SIC NOMA scheme is also derived. Then it is shown that over the derived achievable power allocation interval of user-fairness, rate-lossless non-SIC NOMA can be implemented. As a result, the asymmetric 2PAM could be a promising modulation scheme for rate-lossless non-SIC NOMA of 5G networks, under user-fairness.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.4
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• pp.611-616
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• 2021

This paper investigates the improved outage probability of correlated superposition coding(CSC)/non-successive interference cancellation(SIC) non-orthogonal multiple access(NOMA) scheme. For this, first, we calculate the outage probability of the conventional independent superposition coding(ISC)/SIC NOMA scheme. Then, simulations demonstrate that the outage probability of CSC/non-SIC NOMA improves greatly, with respect to that of conventional ISC/SIC NOMA. As a result, CSC/non-SIC NOMA schemes could be a promising technique in 5G networks, especially with such improved outage probability.

• Korean Journal of Remote Sensing
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• v.23 no.6
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• pp.507-520
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• 2007

Satellite passive microwave(PM) sensors have been observing polar sea ice concentration(SIC), ice temperature, and snow depth since 1970s. Among them SIC is playing an important role in the various studies as it is considered the first factor for the monitoring of global climate and environment changes. Verification and correction of PM SIC is essential for this purpose. In this study, we calculated SIC from KOMPSAT-1 EOC images obtained from Arctic sea ice edges from July to August 2005 and compared with SSM/I SIC calculated from NASA Team(NT) algorithm. When we have no consideration of sea ice types, EOC and SSM/I NT SIC showed low correlation coefficient of 0.574. This is because there are differences in spatial resolution and observing time between two sensors, and the temporal and spatial variation of sea ice was high in summer Arctic ice edge. For the verification of SSM/I NT SIC according to sea ice types, we divided sea ice into land-fast ice, pack ice, and drift ice from EOC images, and compared them with SSM/I NT SIC corresponding to each ice type. The concentration of land-fast ice between EOC and SSM/I SIC were calculated very similarly to each other with the mean difference of 0.38%. This is because the temporal and spatial variation of land-fast ice is small, and the snow condition on the ice surface is relatively dry. In case of pack ice, there were lots of ice ridge and new ice that are known to be underestimated by NT algorithm. SSM/I NT SIC were lower than EOC SIC by 19.63% in average. In drift ice, SSM/I NT SIC showed 20.17% higher than EOC SIC in average. The sea ice with high concentration could be included inside the wide IFOV of SSM/I because the drift ice was located near the edge of pack ice. It is also suggested that SSM/I NT SIC overestimated the drift ice covered by wet snow.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.5
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• pp.35-42
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• 2017

NOMA (Non-orthogonal multiple access) system is the most promising multiple access technology to satisfy the requirements of the spectral efficiency and the performance of 5G cellular systems. NOMA system simultaneously serves multiple users in the power domain, and adapts SIC (Successive interference cancellation) at the receivers to cancel the interference from multiple users. Since in a realistic wireless fading channel the perfect SIC is impossible, the study of the effect of the imperfect SIC to a NOMA system is necessary. This paper considers a cooperative NOMA system with SIC error, and the performance of the system is analytically derived. And the optimum power allocation to minimize the system performance is obtained. When the transmit power is fixed, the distances between a base station and the relay is considered for different SIC errors. The derived analytical results are verified through Monte Carlo simulation, and the results are perfectly matched.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.4 no.3
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• pp.189-196
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• 2011

In this paper, we analyze the error performance of SIC-based signal detection methods in MIMO systems. Considered detection methods are SIC signal detection and LR-SIC signal detection. We derive BLER performance of the methods and the performance is confirmed by computer simulations.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.3
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• pp.457-464
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• 2021

This paper investigates the achievable rate volumes for non-successive interference cancellation(SIC) non-orthogonal multiple access(NOMA) schemes, especially for 3-user correlated information sources(CIS). First, the closed-form expressions for the achievable rate volumes of non-SIC 3-user CIS NOMA are derived. Then it is numerically shown that the large correlation coefficients, as the achievable rate volumes of non-SIC 3-user CIS NOMA is larger than that of conventional SIC 3-user independent information sources(IIS) NOMA. We also demonstrate by various comparisons that the impact of the correlation coefficients of weaker channel gain users on achievable rate volume is more significant than those of stronger channel gain users.

• Journal of Korean Neurosurgical Society
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• v.60 no.4
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• pp.385-390
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• 2017

The doctrine of informed consent, as opposed to medical paternalism, is intended to facilitate patient autonomy by allowing patient participation in the medical decision-making process. However, regrettably, the surgical informed consent (SIC) process is invariably underestimated and reduced to a documentary procedure to protect physicians from legal liability. Moreover, residents are rarely trained in the clinical and communicative skills required for the SIC process. Accordingly, to increase professional awareness of the SIC process, a brief history and introduction to the current elements of SIC, the obstacles to patient autonomy and SIC, benefits and drawbacks of SIC, planning of an optimal SIC process, and its application to cases of an unruptured intracranial aneurysm are all presented. Optimal informed consent process can provide patients with a good comprehension of their disease and treatment, augmented autonomy, a strong therapeutic alliance with their doctors, and psychological defenses for coping with stressful surgical circumstances.

• Journal of Satellite, Information and Communications
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• v.10 no.1
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• pp.22-28
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• 2015

In this paper, we propose a new computationally efficient joint iterative multi-input multi-output (MIMO) detection scheme using a soft interference cancellation and minimum mean squared-error (SIC-MMSE) method. The critical computational burden of the SIC-MMSE scheme lies in the multiple inverse operations of the complex matrices. We find a new way which requires only a single matrix inversion by utilizing the Taylor series expansion of the matrix, and thus the computational complexity can be reduced. The computational complexity reduction increases as the number of antennas is increased. The simulation results show that our method produces almost the same performances as the conventional SIC-MMSE with reduced computational complexity.

• Proceedings of the KSRS Conference
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• 2006.03a
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• pp.153-156
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• 2006

북극과 남극의 해빙을 촬영한 Kompsat-1 EOC 영상을 SSM/I Sea Ice Concentration(SIC)과 비교하였다. EOC 영상은 2005년 $7{\sim}8$월 북극 해빙지역의 가장자리를 지나는 10개 궤도(624 영상)와 $9{\sim}11$월 남극대륙의 가장자리를 지나는 11개 궤도(676 영상)에서 얻어졌다. 그 중 구름의 영향이 없는 약 12%의 영상으로부터 감독분류와 육안분류를 통해 Multi-year ice와 First-year ice(M+F), Young ice(Y), New ice(N)로 해빙의 유형을 구분하여 SIC를 계산하였으며, 이를 NASA Team Algorithm(NTA)으로 계산된 SSM/I SIC와 비교하였다. 북극의 여름철에는 해빙의 시공간적 변화가 매우 크기 때문에 EOC SIC(M+F+Y+N)와 SSM/I SIC의 상관계수는 0.671로 잘 일치하지 않았다. 남극의 봄철에 N을 제외한 EOC SIC(M+F+Y)의 경우 SSM/I SIC와 0.873의 높은 상관계수를 가졌다. 이로부터 NTA로 계산된 남극의 SSM/I SIC가 M과 F를 비롯하여 Y도 포함하는 것을 알 수 있었다.