• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.2A
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• pp.51-60
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• 2005

In this paper, we propose an enhanced SIR measurement algorithm for WCDMA mobile station modem. The proposed algorithm minimizes processing delay by applying velocity estimation-based channel estimator with IIR filter and reduces measured SIR offset by compensating attenuated signal power by using pilot channel(CPICH) in fading channel environment. To improve stability of SIR measurement, we also adopt an IIR filter which can properly reflect variation of fading channel in signal and interference power measurement. We prove that the proposed algorithm outperforms conventional SIR measurement algorithm in mean and jitter of measured SIR. Computer simulation shows that performance results using the proposed algorithm have improvement of approximately 8dB for measured mean and 2dB for measured jitter in the wireless mobile channel, especially in fast mobile speed environment.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.7
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• pp.282-292
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• 2003

In this paper, we evaluate the performance of WCDMA reverse link receiver system with closed loop fast transmit power control (TPC). For fast power control, SIR must be measured precisely. We propose a new SIR measurement algorithm having a simple structure. The proposed algorithm uses unused OVSF code for interference power evaluation. The proposed SIR measurement algorithm is compared to the conventional SIR measurement algorithm in Ref.$^{［1］}$ under closed loop fast TPC. We adopted WMSA channel estimation filter with Κ=2 for mobile radio channel estimation and considered one slot TPC delay. Extensive computer simulation results show that the proposed algorithm using unused OVSF code reduces the required Ε$_{b}$ /Ι$_{0}$ at the BER of 10$^{-3}$ up to 0.9㏈ and has an improved TPC error performance compared to the conventional algorithm.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.4B
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• pp.367-377
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• 2010

In this study, we considered annual maximum rainfall data from 56 weather stations for rainfall frequency analysis using SIR(Sampling Important Resampling) algorithm and Bootstrap method. SIR algorithm is resampling method considering weight in extreme rainfall sample and Bootstrap method is resampling method without considering weight in rainfall sample. Therefore we can consider the difference between SIR and Bootstrap method may be due to the climate change. After the frequency analysis, we compared the results. Then we derived the results which the frequency based rainfall obtained using the data from SIR algorithm has the values of -10%~60% of the rainfall obtained using the data from Bootstrap method.

• Journal of Wetlands Research
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• v.10 no.3
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• pp.125-132
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• 2008

Generally, stationary is considered as a basic assumption in frequency analysis. However, rainfall and flood discharge are changing due to the climate change and climate variability. Therefore, there is a new opinion that changing pattern of rainfall and flood discharge must be considered in frequency analysis. This study suggests the flood frequency analysis methodology using SIR algorithm which was developed from bootstrap could be used for considering climate change. Than is, SIR algorithm is selected for resampling method considering changing pattern of flood discharge and it has been used for resampling method with likelihood function. Resampled flood discharge data considering the increase of flood discharge pattern are used for parametric flood frequency analysis and this results are compared with frequency analysis results by Bootstrap and original observations. As the results, SIR algorithm shows the greatest flood discharge than other methods in all frequencies and this may reflect the increasing pattern of flood discharge due to the climate change and climate variability.

• Journal of Wetlands Research
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• v.13 no.1
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• pp.53-66
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• 2011

We estimated the expected flood damage considering uncertainty which is involved in hydrologic processes and data. Actually, this uncertainty represents a freeboard or safety factor in the design of hydraulic structures. The uncertainty was analyzed using Bootstrap method, and SIR algorithm then the frequency based rainfalls were estimated for each method of uncertainty analysis. Also the benefits for each uncertainty analysis were estimated using 'multi-dimensional flood damage analysis(MD-FDA). As a result, the expected flood damage with SIR algorithm was 1.22 times of present status and Boostrap 0.92 times. However when we used SIR algorithm, the likelihood function should be selected with caution for the estimation of the expected flood damage.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.4
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• pp.957-966
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• 1998

In this paper an imrpoved Signal-to-Interference ratio(SIR)-based call admission control(CAC) algorithm for DS-CDMA cellular system is proposed and its performance is analyzed. This algorithm uses Residual-Capacity defined asthe additional number of initial calls that a base station can accept such that system-wide outage probability will guaranteed to remain below a certain level. the residual capcity at each cell is calculated according to the reverse-link SIR measured not only at the home cell but also the adjacent cells. Then the adjacent cell interference-coupling coefficient .betha. is used. In this work we propose an improved algorithm that .betha. varies according to the traffic load of the home cell. The influence of traffic condition on system performance, namely blocking probability and outage probability, is then examined via simulation. The performance of the improved algorithm is evaluated both under homogeneous and hot spot traffic loads. The results show that the improved algorithm outperforms conventional algorithms under all load values. Under over-load situation, especially, the improved algorithm gives almost constant outage performance the QoS(quality of service) can be guranted.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.9A
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• pp.878-887
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• 2007

In this paper, a fairness scheme is proposed that assigns different number of HS-PDSCH to the service user according to the received SIR of CPICH. Assigned channel number is determined by the SIR level. The highest SIR user gets the number of channels based on the SIR table and the remained channels are assigned to the other SIR users. This scheme can serve the similar maximum service throughput and higher fairness than MAX CIR packet scheduling algorithm. This scheme can also serve the higher service throughput than Proportional Fairness scheme.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.7B
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• pp.1194-1203
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• 2000

본 논문에서는 신호대 간섭비(SIR)의 추정에 채널 추정 값을 이용하지 않는 방식을 제시한다. 제시된 SIR 추정방법은 기존의 방법에 비해 계산의 복잡도 면에서 다소 우수한면서도, 같은 SIR의 추정 값을 가진다. 한편, 전력제어를 수반한 시스템에서는 페이딩 채널의 통계적인 특성이 달라지게 되므로 이에 적합한 채널 추정 방법을 제시하고 그 성능을 분석하였다. 그 결과 도플러 주파수가 증가할수록 제안된 채널 추정 알고리즘이 성능이 우수함을 알 수 있었다.

• The KIPS Transactions:PartC
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• v.10C no.5
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• pp.617-624
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• 2003

This paper proposes a modified DCPC (Distributed Constrained Power Control, M-DCPC) algorithm that can improve the performance of a CDMA power control system. The control performance of the proposed method is verified using two performance measures : the SIR response of each mobile and the outage probability in a cell. As regards the SIR response, in simulations, the M-DCPC algorithm has shown a faster convergence and lower overshoot in transient time than the other power control algorithms when the desired SIR value was varying. For the outage probability. M-DCPC converged to a fixed outage rate faster than CSOPC while also maintaining the system capacity to make as high a connection as CSOPC. In particular, when the desired SIR was varying, CSOPC showed an abrupt outage probability increase during the desired SIR Increase, yet M-DCPC was unaffected.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.8
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• pp.1469-1476
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• 2015

We propose a beam selection algorithm that improves inter sector SIR using a code-book of a circular array antenna in multi-sector wireless mesh network environments. The proposed method improves SIR using a combination of fed back code-book and guarantees QoS of all nodes. Computer simulation exhibits the proposed scheme demonstrates 4.42dB higher SIR than that of the conventional code-book method, QoS with proportional fair is improved by 1.70dB and fact that all nodes are satisfied Qos is also shown.