• Title/Summary/Keyword: signal-to-interference ratio (SIR)

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SIR analysis for Enhancing Image Quality in Underwater Acoustic Lens System (수중음향렌즈 카메라에서 영상 품질 향상을 위한 SIR 분석)

  • Lee, Jieun;Im, Sungbin;Shim, Taebo
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.4
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    • pp.181-190
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    • 2014
  • The underwater acoustic lens system is one of the systems getting high-resolution images on the seafloor by the beam forming method using acoustic lens. The beam forming using acoustic lenses reduces complexity and driving power. When receiving an incoming beam with the acoustic lens array, beam pattern analysis and arrangement problem of the array sensor must be addressed. Introducing SIR (Signal to Interference Ratio), the relationship among sensor interval, beam pattern and image quality would be analyzed. Generally if the sensor interval getting wider, the less effect of the side lobes makes SIR high. If the amplitude of a side lobe is high, SIR is generally getting low. The type of the apodization function changes the width, shape and amplitude of both main lobe and side lobes. Thus an appropriate apodization function can improve SIR. In this paper, SIR is stable at the sensor interval of 13mm with 0-10dB, which is not high relatively. By applying the Chebyshev function, the SIR becomes 80dB over the sensor interval of 37 mm or higher. The Hann and triangular functions demonstrate better SIR when the sensor interval becomes narrower.

Pilot Interference Cancellation in a WCDMA Wireless Repeater (WCDMA 무선 중계기에서 파일럿 간섭제거)

  • Kim, Sun-Ho;Im, Sung-Bin;Lee, Jae-Jin
    • Proceedings of the IEEK Conference
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    • 2008.06a
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    • pp.307-308
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    • 2008
  • In this paper, we propose a mitigation method to reduce the effect of pilot interference at the wireless repeater. This improves the signal to interference ratio (SIR), and enables increased cell capacity and better bits error rates (BER) performance in the WCDMA systems. Simulation studies have been carried out to verify the proposed approach and we obtained promising results.

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Performance of SIR-based power control using unused OVSF codes for WCDMA reverse link receiver (미사용 OVSF 부호를 이용한 WCDMA 역방향 링크 수신기의 SIR 기반 전력제어 성능 분석)

  • 이영용;박수진;안재민;임민중;정성현;최형진
    • 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}$$_{0}$ at the BER of 10$^{-3}$ up to 0.9㏈ and has an improved TPC error performance compared to the conventional algorithm.

Performance Evaluation of a Wireless Home Network in the Presence of Co-Channel Interference (동일채널간섭이 존재하는 홈 네트워크에서의 성능 평가)

  • Roh, Jae-Sung;Ye, Hui-Jin
    • Journal of Digital Contents Society
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    • v.8 no.4
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    • pp.491-497
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    • 2007
  • RPersonal area networking technology is becoming increasingly important in enabling useful wireless home applications. For example, Bluetooth and IEEE 802.11b standards are the most commonly deployed technologies for wireless home applications. However, because both standards share the same unlicensed ISM (Industrial, Scientific, Medical) radio spectrum, severe interference is inevitable and performance can be impaired significantly when heterogeneous devices using the two technologies come into close proximity. In this paper, we research Gaussian FSK Bluetooth system, which is an open specification technology for short-range wireless connectivity between electronic devices. In this paper, we analyzes the effects of co-channel interference on the performance of a Gaussian FSK Bluetooth system. Performance criteria used in the study are the signal to interference power ratio (SIR), interference index, and the bit error rate (BER) in the wireless channel. The effect of co-channel interference from various sources on the performance of a Gaussian FSK Bluetooth system is analyzed using an IGA(Impulsive Gaussian Approximation) method, and these quantities are plotted against Eb/No, $\rho$ and SIR for various channel conditions in figures.

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Spatial Distribution of Mobiles in Cellular Communication Network (이동통신망에서의 셀 내 가입자 분포 분석)

  • Jang, Hee-Seon;Lee, Kwang-Hee;Yoon, Sang-Hum
    • IE interfaces
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    • v.12 no.3
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    • pp.401-405
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    • 1999
  • We present a simulation model to generate the spatial distribution of mobiles in cellular communication network. Three types of spatial distributions are considered; biased, random, and ratio-based distributions. This study also points out and corrects the critical errors performed by Das and Morgera(1997) in getting random location of mobiles. By applying a simple path loss model, the effects of our correction on the signal-to-interference(SIR) ratio are discussed. The numerical results indicate that the variation of SIR in the Das's biased distribution is larger than that of other distributions. As compared with the random distribution, the average SIR error of the biased distribution is 91.1%.

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SIR-based dynamic code allocation method prioritized for handoff call in DS-CDMA cellular system (DS-CDMA 셀룰러 시스템에서 SIR에 기반을 둔 핸드오프 호 우선순위 동적코드할당방식)

  • 이용기;유명수;이정규
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.23 no.9A
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    • pp.2131-2140
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    • 1998
  • Signal-to-interference ratio (SIR)-based dynamic code allocation method to be rioritized for handoff call is proposed and evaluated in a direct sequence-code division multiple access (DS-CDMA) cellular systm. Proposed method allocates a code to a mobile terminal according to the restidual capacity computed by SIR in the base station. We consider the voice activity detection to increase the system capacity. We evaluate the performance of proposed method with computer simulation. And the handoff decision function that controls handoff of mobile terminal is interodcued. The proposed method provide much improvement in the forced termination probability and handoff call fail probability.

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Spectrum Reuse with Power Control for Two-Tier Femtocell Networks

  • Kim, Youngju;Wang, Hano;Hong, Daesik
    • IEIE Transactions on Smart Processing and Computing
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    • v.3 no.5
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    • pp.275-284
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    • 2014
  • This paper considers two-tier networks consisting of macrocells and femtocells operating in the same spectrum. This paper proposes a femtocell spectrum reuse scheme that determines the shared spectrum and transmit power for the femtocells to mitigate the effects of cross-tier interference between the macrocells and femtocells. The proposed scheme provides macrocell throughput that is unaffected by the increasing number of femtocells per cell site and improves the femtocell signal quality at the same time by limiting the cross-tier interference. This study analyzed the per-tier signal-to-interference ratio (SIR) and outage probability of the proposed scheme to investigate the macrocell and femtocell performance. The total throughput of the proposed scheme was analyzed based on the outage probabilities. The analysis and numerical results proved that high femtocell throughput can be achieved using only a small fraction of the spectrum while protecting the macrocell throughput. As a result, an improved total throughput was achieved enforcing higher spatial reuse.

A Hand-off Technique for Cellular Networks Using Game Theory (셀룰라 네트워크에서 게임 이론을 이용한 핸드오프 기법)

  • Hong, Jin-Dae;Lee, Sin-Kyu;Kim, Hyun-Tae;Ra, In-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.11
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    • pp.2399-2404
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    • 2009
  • In cellular network systems one of the most significant quality metrics to measure quality of performance is the average number of call drops in a system. It ensures that the active calls in the system are successfully completed without being dropped in the mid communication for ultimate customer satisfaction. Hand-off mechanism increases cellular system reliability by seamless continuation of active calls by transferring active calls from one base station to another. In this paper, we study and propose a simple hand-off mechanism using game theory. We conclude that using the simple QoS utility function proposed in this paper, our optimal deterministic hand-off strategy is to transfer the active calls to the base station with greater signal-to-interference ratio (SIR) and greater number of available channels.

Mobile Target Speed Estimation in Urban Environments with Adaptive Power Control (도시환경에서 적응전력제어를 이용한 이동국 속도추정)

  • Lee, Hyeon-Cheol;Lee, Jong Tae;Ryu, Sang Burm;Kang, Eun Su
    • Journal of Satellite, Information and Communications
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    • v.11 no.1
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    • pp.46-50
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    • 2016
  • The adaptive power control of Code Division Multiple Access (CDMA) systems for communications between User Equipments (UEs) with a link-budget based Signal-to-Interference Ratio (SIR) estimate which has distance information is applied to three inner loop power control algorithms. The speed estimation performances of these algorithms with their consecutive Transmit-Power-Control (TPC) ratios are compared to each other, and it is concluded that the speed can be estimated using the TPC ratio information of Consecutive TPC Ratio Step-size Closed Loop Power Control (CS-CLPC) and Fixed Step-size Power Control (FSPC).

Co-Channel Interference Cancellation in Cellular OFDM Networks - PART I : Maximum-Likelihood Co-Channel Interference Cancellation with Power Control for Cellular OFDM Networks

  • Mohaisen, Manar;Chang, Kyung-Hi
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.5A
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    • pp.409-416
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    • 2007
  • In cellular orthogonal frequency division multiplexing (OFDM) networks, co-channel interference (CCI) leads to severe degradation in the BER performance. To solve this problem, maximum-likelihood estimation (MLE) CCI cancellation scheme has been proposed in the literature. MLE CCI cancellation scheme generates weighted replicas of the transmitted signals where weights represent the estimated channel transfer functions. The replica with the smallest Euclidean distance from the received signal is selected and data are detected. When the received power of the desired and interference signals are nearly the same, the BER performance is degraded. In this paper, we propose a closed-loop power control (PC) scheme capable of detecting the equal received power situation at the mobile station (MS) receiver by using the newly introduced parameter power ratio (PR). When this situation is detected, the MS sends a feedback to the desired base station (BS) which boosts the transmission power in the next frame. At cell edge where signal to interferer ratio (SIR) is considered to have average value between -5 dB and 10 dB, computer simulations show that the proposed CCI cancellation scheme has a gain of 7 dB at 28 Km/h.