• Title/Summary/Keyword: 전이중

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A Data Ferrying-Based Virtual Full-Duplex Relaying Scheme with Two UAVs (두 UAV를 활용하는 데이터 페리 기반의 가상 전이중 중계전송 기법)

  • Woo, Dong Hyuck;Hwang, Ho Young
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.24 no.12
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    • pp.1639-1645
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    • 2020
  • In this paper, we propose a virtual full-duplex relaying scheme based on data ferrying using two unmanned aerial vehicles (UAVs). By utilizing high mobility of two UAVs, the proposed relaying scheme can make each UAV communicate with a source node or a destination node when the UAV is near the source node or the destination node. The proposed relaying scheme can overcome the performance limitations of the half-duplex relaying and the implementation constraints of the full-duplex relaying. In addition, we propose an algorithm to shift the center point of two UAVs' trajectory with consideration of inter-relay interference (IRI). We show the simulation results of our proposed trajectory's center point shift algorithm. From the simulation results, it is shown that our proposed relaying scheme can achieve higher end-to-end spectral efficiency (SE) than the conventional static relaying scheme.

Performance Analysis of 2nd order Self-Interference Cancellation for In-Band Full-Duplex System (동일대역 전이중 통신시스템에서 2차 구조의 자기간섭신호 제거 기술 성능 분석)

  • Song, JinHyuk;Baek, MyungSun;Jung, JoonYoung
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2019.11a
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    • pp.61-62
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    • 2019
  • 최근 자원 효율성을 증대하기 위하여 차세대 유무선 통신시스템에서 동일대역 전이중 방식(In-band full-duplex, FDX)을 채택하고 있다. 하지만 전이중 방식은 송수신이 동시에 이루어지기 때문에 하향신호와 상향신호가 더해져 수신된다. 따라서 원하는 신호를 수신하기 위해 자기간섭(SI: self-interference)으로 존재하는 하향 신호를 제거하는 기술이 요구된다. 본 논문에서는 DOCSIS 3.1 기반 케이블 방송시스템에서 2차 구조의 자기간섭신호 제거(SIC: SI cancellation)기술을 제안하고 실시간 성능을 분석한다.

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Performance Analysis of Self-Interference Cancellation in Frequency Domain for in Band Full-Duplex System (동일대역 전이중 통신시스템에서 주파수 영역 자기간섭신호 제거 성능 분석)

  • Song, JinHyuk;Baek, MyungSun;Ra, SangJung;Jung, JoonYoung
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2018.11a
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    • pp.101-103
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    • 2018
  • 최근 자원 효율성을 증대하기 위하여 차세대 유무선 통신시스템에서 동일대역 전이중 방식(in band full-duplex, FDX)을 채택하고 있다. 하지만 전이중 방식은 송수신이 동시에 이루어지기 때문에 하향신호와 상향신호가 더해져 수신된다. 따라서 원하는 신호를 수신하기 위해 자기간섭(SI: self-interference)으로 존재하는 하향 신호를 제거하는 기술이 요구된다. 본 논문에서는 주파수영역에서 자기간섭신호 제거(SIC: SI cancellation)하는 방법에 대해서 제안하고 실제 RF를 통과한 신호에 적용하여 성능을 분석한다.

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A method of Implementation in 1000BASE-X PCS layer (1000BASE-X PCS 구현 방안)

  • 이승수;정인택;송상섭
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.26 no.5A
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    • pp.873-878
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    • 2001
  • 광케이블을 이용한 기가비트 이더넷은 8B/10B 선로부호 방식을 채택하여 전이중 통신뿐만 아니라 CSMA/CD 방식의 반이중 통신을 지원토록 규정되어 있다. 또한 링크를 공유하고 있는 2대의 1000BASE-X 장치 사이에 구성정보를 교환하여 가장 적합한 통신모드로 동작시킬 수 있는 자동절충 기능을 지원해야 한다. 본 논문에서는 비교적 기능이 간단하고 구현이 용이한 기존의 전이중 방식만의 PCS 설계 방법과 비교하여 반이중 방식까지 지원할 수 있는 PCS 부계층을 기가비트 이더넷 스위치 시스템의 ASIC 칩 안에 구현한 적용 예를 바탕으로 PCS 설계 규격, 구조 및 방법 등을 제시한다.

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A Study on 3-level Communication Method using Half-Bridge (Half-Bridge를 이용한 3-레벨 통신방식에 관한 연구)

  • Park, Sung-Jun;Hong, Sung-Mun;Lim, Sang-Kil
    • Proceedings of the KIPE Conference
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    • 2019.07a
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    • pp.245-247
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    • 2019
  • 본 논문에서는 시분할 방식에 의한 전이중 통신방식을 사용할 경우 통신속도에 대한 단점을 극복하기 위해 통신신호 레벨에 의한 완전한 전이중 통신방식 구현이 가능한 새로운 통신용 하드웨어 장비를 제안한다. 제안된 통신하드웨어는 2선 방식 통신으로 통신하는 두 장비에서 동일 통신선에 발신신호를 인가함과 동시에 수신 신호를 검출할 수 있는 방식으로 동 시간에 발신과 수신이 가능한 구조이다.

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Outage Optimal Transmission Strategy for Full-Duplex Relay System (전이중 릴레이 시스템에서 오수신 확률을 최소화 시키는 전송 기법)

  • Lee, Sun-Young;Kim, Seong-Lyun
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.11A
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    • pp.853-860
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    • 2011
  • In this paper, we proposed a transmission scheme for a full-duplex relay system that minimizes outage probability. A relay system with the full-duplex relay can mitigate resource inefficiency of a half-duplex relay system. However, the mobile station suffers from the interference because the base station and the relay station transmits signal simultaneously to the mobile station. First, we suggest a layered broadcasting for full-duplex relaying. Second, we derive an optimal power allocation for the layered broadcasting in terms of the outage probability minimization. The proposed algorithm shows better performance than a half-duplex relaying system with and without the diversity, and a conventional full-duplex relaying system.

Multiuser Precoding and Power Allocation with Sum Rate Matching for Full-duplex MIMO Relay (전이중 MIMO 릴레이를 위한 다중 사용자 Precoding 및 Sum Rate 정합 기반 전력 할당 기법)

  • Lee, Jong-Ho;Shin, Oh-Soon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.12C
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    • pp.1020-1028
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    • 2010
  • Relay has attracted great attention due to its inherent capability to extend the service coverage and combat shadowing in next generation mobile communication systems. So far, most relay technologies have been developed under the half-duplex (HD) constraint that prevents relays from transmitting and receiving at the same time. Although half-duplex relay (HDR) is easy to implement, it requires partitioning of resource for transmission and reception, reducing the whole system capacity. In this paper, we propose a multinser precoding and power control scheme with sum rate matching for a full-duplex (FD) multiple-input multiple-output (MIMO) relay. Full-duplex relay (FDR) can overcome the drawback of HDR by transmitting and receiving on the same frequency at the same time, while it is crucial to reduce the effect of self-interference that is caused by its own transmitter to its own receiver. The proposed precoding scheme cancels the self-interference of the FDR as well as to support multiuser MIMO. Moreover, we suggest a power allocation scheme for FD MIMO relay with the constraint that the sum rate of the relay's received data streams is equal to that of the relay's transmit data streams.

Performance Analysis of In-Band Full-duplex Communication Systems with Self-Interference Cancellation (동일대역 전이중 방식 통신 시스템에서 자기간섭 제거에 따른 성능 분석)

  • Wang, Woowan;Park, Hyuncheol
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.41 no.3
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    • pp.331-337
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    • 2016
  • In this paper, we analyze performances of in-band full-duplex communication system and self-interference (SI) suppression methods in environment where there exists the SI signal. The SI has to be removed to achieve required error rate performance of the system in order - propagation domain, analog domain and digital domain. In propagation domain, the SI signal is attenuated by separating transmitted and received beams physically. In analog and digital domain, after reconstruction of the SI signal using channel estimates and transmit signal, the SI signal can be cancelled from the desired signal. In this paper, assuming that the SI signal can be sufficiently reduced in propagation domain, we demonstrate that the in-band full-duplex communication system can achieve the target error rate by suppressing the SI signal in order - analog and digital domain, based on channel estimates that can be obtained by the method of Least squares.

User Scheduling Algorithm Based on Signal Quality and Inter-User Interference for Outage Minimization in Full-Duplex Cellular Networks (전이중 셀룰라 네트워크에서 아웃티지 최소화를 위한 신호 품질과 사용자간 간섭량 기반의 사용자 스케쥴링 알고리즘)

  • Choi, Hyun-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.11
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    • pp.2576-2583
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    • 2015
  • In a full-duplex (FD) wireless cellular network, uplink (UL) users induce the severe inter-user interference to downlink (DL) users. Therefore, a user scheduling that makes a pair of DL user and UL user to use the same radio resource simultaneously influences the system performances significantly. In this paper, we first formulate an optimization problem for user scheduling to minimize the occurrence of outage, aiming to guarantee the quality of service of users, and then we propose a suboptimal user scheduling algorithm with low complexity. The proposed scheduling algorithm is designed in a way where the DL user with a worse signal quality has a higher priority to choose its UL user that causes less interference. Simulation results show that the FD system using the proposed user scheduling algorithm achieves the optimal performance and significantly decreases the outage probability compared with the conventional half-duplex cellular system.

Evaluation on the Compression Capacity of Transfer Slab Systems according to the Variation of Column Length (기둥의 길이변화에 따른 전이슬래브 시스템의 압축성능 평가)

  • Sim, Yeon-Ju;Choi, Chang-Sik
    • Journal of the Korea Concrete Institute
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    • v.28 no.6
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    • pp.695-702
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    • 2016
  • This paper presents compression capacity of transfer system in pilotis subjected to axial load. Recently, transfer system is usually used in low floors of wall-typed apartments when members' sections are suddenly changed between upper walls and bottom columns. It can help transfer loads from the walls to the columns. Especially, a transfer girder system is usually used as one of transfer systems applied to a pilotis. However, the transfer girder system has low constructability and economics. Therefore, the other transfer system with transfer slab was suggested and has been studied. In this paper, to evaluate the compression capacity of transfer slab, tests were conducted on pilotis transfer slab systems subjected to axial load. First of all, two specimens were determined by FEM. The main parameter is length of the bottom columns. The lengh of the bottom columns were 40% and 50% of length of upper walls in the tranfer slab specimens. Results showed that the compression capacity of piloti transfer systems subjected to axial load was affected by length of bottom columns. The compression capacity is 52% higher than design strength for specimen with the bottom column's length of 40% of length of the upper wall and 46% for specimen with the bottom column's length of 50% of length of the upper wall.