• Title/Summary/Keyword: Signal to Interference-plus-Noise Ratio (SINR)

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An Adaptive Path Selection Technique Considering Time Difference of Arrival in Multi-hop Relay Systems (다중 홉 릴레이 시스템에서 전파 시간 차이가 고려된 적응적 경로 선택 기법)

  • Woo, Kyung-Soo;Park, Chang-Hwan;Yoo, Hyun-Il;Kim, Jae-Kwon;Han, Seung-Hee;Cho, Yong-Soo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.4A
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    • pp.291-301
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    • 2009
  • In this paper, the effect of ISI(Inter-Symbol Interference) and ICI(Inter-Carrier Interference) due to time difference of arrival on OFDMA-based mobile multi-hop relay (MMR) systems is analyzed. Analyses are performed for the ISI caused by the previous OFDMA symbol transmitted from neighboring macro or relay cell as well as the ISI caused by the next OFDMA symbol transmitted from neighboring macro or relay cell. Then, an effective SINR(Signal to Interference plus Noise Ratio) estimation method and a path selection method considering time difference of arrival are proposed to minimize the effect of ISI and ICI. It is shown by simulation that the performance degradation caused by time difference of arrival can be significantly mitigated when the proposed path selection method is applied to the uplink of OFDMA-based MMR systems.

Improvement of Applebaum Array Interference Cancellation in Smart Antenna System by Using Covariance Matrix Adjustment

  • Tanakorn Sukontapong;Chuwong Phogcharoenpanich;Phaisan Ngamjanyaporn;Monai Krairiksh
    • Proceedings of the IEEK Conference
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    • 2002.07b
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    • pp.727-730
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    • 2002
  • This paper proposes the interference cancellation improvement in smart antenna system by using Applebaum array covariance matrix adjustment. This technique adds the specific adjustable multipliers with both desired signal covariance matrix and interference signal covariance matrices in order to overcome some disadvantages and improve the interference cancellation efficiency of Applebaum array. It is based on the desired and undesired signal power or desired signal-to-interference-plus-thermal noise ratio (SINR). As the result from demonstration, the proposed technique can improve and increase the interference cancellation efficiency in smart antenna better than the conventional technique.

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Performance of Distributed MISO Systems Using Cooperative Transmission with Antenna Selection

  • Park, Jong-Hyun;Kim, Jae-Won;Sung, Won-Jin
    • Journal of Communications and Networks
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    • v.10 no.2
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    • pp.163-174
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    • 2008
  • Performance of downlink transmission strategies exploiting cooperative transmit diversity is investigated for distributed multiple-input single-output (MISO) systems, for which geographically distributed remote antennas (RA) in a cell can either communicate with distinct mobile stations (MS) or cooperate for a common MS. Statistical characteristics in terms of the signal-to-interference-plus-noise ratio (SINR) and the achievable capacity are analyzed for both cooperative and non-cooperative transmission schemes, and the preferred mode of operation for given channel conditions is presented using the analysis result. In particular, we determine an exact amount of the maximum achievable gain in capacity when RAs for signal transmission are selected based on the instantaneous channel condition, by deriving a general expression for the SINR of such antenna selection based transmission. For important special cases of selecting a single RA for non-cooperative transmission and selecting two RAs for cooperative transmission among three RAs surrounding the MS, closed-form formulas are presented for the SINR and capacity distributions.

Signal-Subspace-Based Simple Adaptive Array and Performance Analysis (신호 부공간에 기초한 간단한 적응 어레이 및 성능분석)

  • Choi, Yang-Ho
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.47 no.6
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    • pp.162-170
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    • 2010
  • Adaptive arrays reject interferences while preserving the desired signal, exploiting a priori information on its arrival angle. Subspace-based adaptive arrays, which adjust their weight vectors in the signal subspace, have the advantages of fast convergence and robustness to steering vector errors, as compared with the ones in the full dimensional space. However, the complexity of theses subspace-based methods is high because the eigendecomposition of the covariance matrix is required. In this paper, we present a simple subspace-based method based on the PASTd (projection approximation subspace tracking with deflation). The orignal PASTd algorithm is modified such that eigenvectora are orthogonal to each other. The proposed method allows us to significantly reduce the computational complexity, substantially having the same performance as the beamformer with the direct eigendecomposition. In addition to the simple beamforming method, we present theoretical analyses on the SINR (signal-to-interference plus noise ratio) of subspace beamformers to see their behaviors.

The Output SINR of the Linearly Constrained Broadband Beamformer (선형 제한 조건을 갖는 광대역 빔 형성기의 출력 SINR)

  • Gwak, Byeong-Jae;Kim, Gi-Man;Cha, Il-Hwan;Yun, Dae-Hui
    • The Journal of the Acoustical Society of Korea
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    • v.13 no.2E
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    • pp.14-19
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    • 1994
  • In this paper, we derive expressions for the output signal-to-interference plus noise ratio(SINR) of the linearly constrained broadband beamformer in noncoherent situations using a vector approach. The incoming broadband signals are assumed to have flat spectra.

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Dynamic User Association based on Fractional Frequency Reuse

  • Ban, Ilhak;Kim, Se-Jin
    • Journal of Integrative Natural Science
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    • v.13 no.1
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    • pp.1-7
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    • 2020
  • This paper proposes a novel fractional frequency reuse(FFR) based on dynamic user distribution. In the FFR, a macro cell is divided into two regions, i.e., the inner region(IR) and outer region(OR). The criterion for dividing the IR and OR is the distance ratio of the radius. However, these distance-based criteria are uncertain in measuring user performance. This is because there are various attenuation phenomena such as shadowing and wall penetration as well as path loss. Therefore, we propose a novel FFR based on dynamic user classification with signal to interference plus noise ratio(SINR) of macro users and classify the FFR into two regions newly. Simulation results show that the proposed scheme has better performance than the conventional FFR in terms of SINR and throughput of macro cell users.

A Rapid Convergent Max-SINR Algorithm for Interference Alignment Based on Principle Direction Search

  • Wu, Zhilu;Jiang, Lihui;Ren, Guanghui;Wang, Gangyi;Zhao, Nan;Zhao, Yaqin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.5
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    • pp.1768-1789
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    • 2015
  • The maximal signal-to-interference-plus-noise ratio (Max-SINR) algorithm for interference alignment (IA) has received considerable attention for its high sum rate achievement in the multiple-input multiple-output (MIMO) interference channel. However, its complexity may increase dramatically when the number of users approaches the IA feasibility bound, and the number of iterations and computational time may become unacceptable. In this paper, we study the properties of the Max-SINR algorithm thoroughly by presenting theoretical insight into the algorithm and by providing the potential of reducing the overall computational cost. Furthermore, a novel IA algorithm based on the principle direction search is proposed, which can converge more rapidly than the conventional Max-SINR method. In the proposed algorithm, it searches along the principle direction, which is found to approximately point to the convergence values, and can approach the convergence solutions rapidly. In addition, the closed-form solution of the optimal step size can be formulated in the sense of minimal interference leakage. Simulation results demonstrate that the proposed algorithm outperforms the conventional minimal interference leakage and Max-SINR algorithms in terms of the convergence rate while guaranteeing the high throughput of IA networks.

3D Coverage Analysis of LTE Network for UTM Services Considering Actual Terrain and Base Station Layouts (실제 지형과 기지국 배치를 고려한 UTM 통신을 위한 LTE 통신망 3차원 커버리지 분석)

  • Jang, Minseok;Kim, Daeho;Kim, Hee Wook;Jung, Young-Ho
    • Journal of Advanced Navigation Technology
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    • v.26 no.2
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    • pp.91-98
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    • 2022
  • Unmanned aircraft system traffic management (UTM) service for the safe operation of unmanned aerial vehicles (UAV) such as drones using commercial communication networks such as long-term evolution (LTE) and 5G in low-altitude areas of 150m or less is being studied in several countries. In this paper, whether it is possible to secure three-dimensional (3D) coverage for UTM service using the existing LTE cellular network for terrestrial usersis analyzed through simulations. The practicality in the real environment is confirmed by performing performance analysis in the actual topographical environment and the LTE base station layouts in Korea. According to the analysis results, as the altitude increases, the number of line-of-sight (LOS) interference base stations increases, resulting in a worse signal to interference plus noise ratio (SINR), but coverage is secured except for the limited areas within 150m. was confirmed to be possible. In addition, it is confirmed that a significant proportion of outage areas could be reduced by placing a small number of additional base stations for the outage area.

Performance Analysis of DCMP and ZF based on Spatial Channel Response Estimation by ESPRIT (ESPRIT에 의한 공간 채널응답 추정치에 기초를 둔 방향구속 전력 최소화법과 제로포싱 알고리즘의 성능평가)

  • 정중식;임정빈;안영섭
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2002.11a
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    • pp.169-174
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    • 2002
  • It has known that the DCMP(Directionally Constrained Minimization of power)and the ZF(Zero Forcing) can improve the SINR performance of an array antenna system by using spatial signature of wireless channel. This paper analyzes performance of DCMP and ZF in multiple scattering environments. To obtain the spatial signature of wireless channel. bothe DOA(Directional of Arrival) and AS(Angular Spread) of the received signals were estimated by using ESPRIT. The performance of the DCMP and the ZF was analyzed theoretically. Through computer simulation, the SINR performance were evaluated.

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SINR based Maximum Link Scheduling with Uniform Power in Wireless Sensor Networks

  • Huang, Baogui;Yu, Jiguo;Yu, Dongxiao;Ma, Chunmei
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.11
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    • pp.4050-4067
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    • 2014
  • In wireless sensor networks, link scheduling is a fundamental problem related to throughput capacity and delay. For a given set of communication requests $L=\{l_1,l_2,{\cdots},l_n\}$, the MLS (maximum link scheduling) problem aims to find the largest possible subset S of Lsuch that the links in S can be scheduled simultaneously. Most of the existing results did not consider bidirectional transmission setting, which is more realistic in wireless sensor networks. In this paper, under physical interference model SINR (signal-to-noise-plus-interference-ratio) and bidirectional transmission model, we propose a constant factor approximation algorithm MLSA (Maximum Link Scheduling Algorithm) for MLS. It is proved that in the same topology setting the capacity under unidirectional transmission model is lager than that under bidirectional transmission model. However, compared with some work under unidirectional transmission model, the capacity of MLSA is improved about 28% to 45%.