IEEE 802.16 BWA 환경에서의 가입자 수용용량 분석

임석구 한국콘텐츠학회 2005 한국콘텐츠학회논문지 Vol.5 No.6

Request about fast diffusion of internet and high-capacity multimedia service is increasing day after day. Because existent wireless LAN is short range, if subscriber is far away in base station transceiver system(Base Station), subscriber's quality of service becomes low, and wileless internet is expensive. Lately, WiBro(Wireless Broadband Internet) system that is developed in domestic by world first, is high-speed portable internet service that is situated in middle area of mobile phone and wireless LAN. In this paper, service traffic model and characteristics are analyzed to provide multimedia service based on IEEE 802.16 BWA accomplishes base of WiBro and simulation is conducted according to various traffic mixing ratio. Finally, on the basis of these simulation results, maximum allowable number of subscriber per cell is calculated. 인터넷의 급속한 보급과 대용량 멀티미디어 서비스에 대한 요구가 나날이 증가하고 있다. 기존의 무선랜은 도달거리가 짧아서 가입자가 기지국(Base Station)에서 멀어지면 서비스 품질이 저하되고, 무선인터넷은 사용비용이 높다. 최근에 세계 최초로 국내에서 개발한 휴대 인터넷 시스템인 와이브로(WiBro: Wireless Broadband Internet) 시스템은 휴대폰과 무선랜의 중간 영역에 위치한 이동초고속인터넷서비스이다. 본 논문에서는 와이브로 시스템의 근간을 이루는 IEEE 802.16 BWA을 기반으로 멀티미디어 서비스를 제공하기 위해서 서비스별 트래픽 모델과 특성을 분석하고, 다양한 트래픽 혼합 비율에 따라 시뮬레이션을 수행하였으며, 이를 토대로 최종적으로는 WiBro 시스템에서 셀 당 수용 가능한 최대 가입자 수를 산출하였다.

Independent Turbo Coding and Common Interleaving Method among Transmitter Branches Achieving Peak Throughput of 1 Gbps in OFCDM MIMO Multiplexing

Junichiro Kawamoto,Takahiro Asai,Kenichi Higuchi,Mamoru Sawahashi 한국전자통신연구원 2004 ETRI Journal Vol.26 No.5

This paper proposes a common interleaving method associated with independent channel-encoding among transmitter antenna branches in orthogonal frequency and code division multiplexing based on multiple-input multiple-output (MIMO) multiplexing to achieve an extremely high throughput such as 1 Gbps using a 100 MHz bandwidth. This paper also investigates the average packet error rate performance as a function of the average received signal energy per bit-to-background noise power spectrum density ratio (Eb/N0). We found that the loss in the required average received Eb/N0 of the proposed method is only within approximately 0.3 dB in up to a 12-path Rayleigh fading channel, using 16QAM and Turbo coding with a coding rate of 5/6. We also clarify that even for a large fading correlation among antenna branches, 1 Gbps is still possible by increasing the transmission power. Therefore, the proposed method reduces the processing rate to 1/4 in the turbo decoder with only a slight loss in the required average received Eb/N0.

OFDM-CDMA기반의 광대역 무선접속시스템에서 공간-시간부호의 성능분석

강민구 ( Min-goo Kang ) 한국인터넷정보학회 2006 인터넷정보학회논문지 Vol.7 No.1

본 논문에서는 OFDM-CDMA기반의 광대역 무선 접속시스템에서 다중 안테나를 적용한다. 이로서 시간영역에서 윈도우 기반의 채널추정 기법과 OFDM기반의 공간영역에서 다중 안테나 전송시스템에서 채널추정의 불완전성을 극복하기 위한 다채널 분리용 프리앰블을 적용함으로서 광대역 무선 접속시스템에서 사용자수를 최대로 확대하고 사용자 용량을 증대하는 광대역 무선접속시스템의 성능을 분석하였다. In this paper, a channel estimation based on the time-domain windowing and its imperfectness in OFDM-based multiple-antenna transmission systems are analyzed with an emphasis on a preamble design for multi-channel separation. From the computer simulation results, the OFDM-CDMA system applying a space-time-frequency diversity with a full-rate full diversity code can give the diversity of D=4 and D=8 for both multi-user cases of maximum user and half user capacities, respectively

Design and performance evaluation of a 156-Mb/s point-to-multipoint millimeter-wave fiber-radio access link

Choi, Sung Tae,Yang, Ki Seok,Nishi, Seiji,Shimizu, Satoru,Tokuda, Kiyohito,Kim, Yong Hoon Wiley Subscription Services, Inc., A Wiley Company 2006 MICROWAVE AND OPTICAL TECHNOLOGY LETTERS Vol.48 No.6

<P>A 60-GHz point-to-multipoint (P-MP) fiber-radio access link with data rate of 156 Mb/s is presented. For a compact system configuration, a small-size 60-GHz transceiver module with planar antennas is developed. A point-to-point (P-P) full-duplex fiber-optic configuration is extended to the scheme with multiple access points (APs) by using a tree coupler and a dense wavelength-division multiplexing (DWDM) multiplexer (MUX). The bit error rate (BER) performances of the 60-GHz fiber-radio access link are measured and compared. Furthermore, the effect of the extension to the scheme with multiple APs is evaluated. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1219–1222, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21576</P>

Fair Scheduling and Throughput Maximization for IEEE 802.16 Mesh Mode Broadband Wireless Access Networks

ALAM, Muhammad Mahbub,HAMID, Md. Abdul,RAZZAQUE, Md. Abdur,HONG, Choong Seon The Institute of Electronics, Information and Comm 2010 IEICE TRANSACTIONS ON COMMUNICATIONS - Vol.93 No.6

<P>Broadband wireless access networks are promising technology for providing better end user services. For such networks, designing a scheduling algorithm that fairly allocates the available bandwidth to the end users and maximizes the overall network throughput is a challenging task. In this paper, we develop a centralized fair scheduling algorithm for IEEE 802.16 mesh networks that exploits the <I>spatio-temporal bandwidth reuse</I> to further enhance the network throughput. The proposed mechanism reduces the length of a transmission round by increasing the number of non-contending links that can be scheduled simultaneously. We also propose a greedy algorithm that runs in polynomial time. Performance of the proposed algorithms is evaluated by extensive simulations. Results show that our algorithms achieve higher throughput than that of the existing ones and reduce the computational complexity.</P>

Performance Analysis of OFDM-CDMA Systems using Space-Time Coding

Kang, Mingoo The Korea Institute of Information and Commucation 2004 한국정보통신학회논문지 Vol.8 No.2

본 논문에서는 무선 광대역 통신망을 위한 OFDM-CDMA 광대역시스템을 설계하였다. 다중채널에서 프리앰블 설계기법을 활용함으로서, OFDM 기반의 다중안테나 전송시스템에서 시간영역의 윈도우기법의 활용에 의한 채널추정이 가능하다. 시간영역에서 직교하는 다중 안테나를 위한 각각의 프리앰블을 설계함으로서 ETSI HIPERLAN/2과 IEEE-802.11a표준에 적용가능한 채널 추정기법을 제안한다. 또한, OFDM-CDMA 기반의 광대역망에서 성능개선을 위한 다이버시티 효과를 분석하였으며, 두개의 레일레이 페이딩 채널에서 얻을 수 있는 최대의 다이버시티 이득을 계산하였다. 본 논문의 시뮬레이션 결과로 완전한 속도와 완전한 다이버시티를 가진 시공간-주파수 다이버시티기법을 적용한 OFDM-CDMA시스템에서 D=4, D=8 다이버시티의 최대 사용자수 및 절반의 사용자인 경우의 대한 다중 사용자 용량에 대한 성능을 분석하였다. In this paper, an OFDM-CDMA broadband system is considered for a possible candidate of fixed wireless broadband access network applications. With an emphasis on a preamble design for multi-channel separation, we address a channel estimation based on the time-domain windowing and its imperfectness in OFDM-based multiple-antenna transmission systems. By properly designing each preamble for multiple antennas to be orthogonal in the time domain, the channel estimation can be applied to the ETSI HlPERLAN/2 and IEEE-802.11a standards in the case of more than two transmit antennas. Also, an effect of diversity techniques on the performance of OFDM-CDMA based broadband wireless access networks is investigated and the maximum achievable diversity gain for a two-path Rayleigh fading environment is evaluated Simulation results show that the OFDM-CDMA system applying a space-time-frequency diversity with a full-rate full diversity code can give the diversity of D = 4 and D = 8 for both multi-user cases of maximum user and half user capacities, respectively.

도시철도 지하구간에 모바일 핫스팟 네트워크 구현을 위한 연구

김동하(D. H. Kim),유근규(G. G. Yu),이덕규(D. G. Lee) 한국도시철도학회 2014 한국도시철도학회논문집 Vol.2 No.3

Mobile Hotspot Network supports the efficient vehicle group mobile communication that has advantages of mobile cellular communication systems and Wireless Fidelity. This technology acts as a relay between outside base radio station which is linked on the Internet and passengers to establish Access Point with radio interface in vehicles. This paper provides the status of the urban railway wireless communication network and the classification of 18GHz radio communication technology in order to apply Mobile Hotspot Network(MHN) to subway tunnel. Using millimeter wave, MHN serves 100 times faster high-speed data communication than the previous Wireless Broadband Backhaul. It also establishes requirements for metro railway environment and presents business model to study radio-wave propagation characteristics analysis of scattering and reflection electromagnetic waves by subway tunnels structure, optimum antenna arrangement, and handover algorithm.

IEEE 802.16 시스템의 슬립모드 동작을 위한 트래픽 인디케이션 방식의 개선

김범준(Beom-Joon Kim) 한국전자통신학회 2013 한국전자통신학회 논문지 Vol.8 No.6

IEEE 802.16 표준 규격[1]은 광대역무선접속시스템을 구현하기 위한 기술을 명시하고 있고 특히 이동 단말의 전력 소모를 최소화하기 위한 슬립모드(sleep mode)에 대한 내용도 포함되어 있다. 본 논문에서는 IEEE 802.16 표준 규격에 기술되어 있는 슬립모드의 기본 동작에 대해서 설명하고 이동 단말의 전력절감효율을 높일 수 있는 개선 방안을 제안한다. 제안하는 방안은 기존의 트래픽 인디케이션 메시지의 형식을 다소 수정함으로써 슬립모드에 있는 이동단말이 주기적으로 수신해야 하는 데이터 량을 줄이는 동시에 주기적 레인징과 같은 동작을 지시할 수 있다는 장점이 있다. IEEE 802.16 standard specifies the broadband wireless access (BWA) system including sleep mode to minimize the power consumption by a mobile station (MS). This paper outlines the overall operation of sleep mode and proposes a method to improve the power saving efficiency of the IEEE 802.16 sleep mode. The proposed method not only decreases the number of bytes that a MS in sleep mode needs to receive during listening interval but allows to indicate a control-specific operation such as periodic ranging.

IEEE 802.16 메쉬 네트워크에서의 SN-Protected 네트워크 엔트리 프로세스

임립상(Lin Lixiang),유상조(Sang-jo Yoo) 한국통신학회 2010 韓國通信學會論文誌 Vol.35 No.6(네트워크)

The workgroup of IEEE 802 proposed the IEEE 802.16 standard, also known as WiMAX, to provide broadband wireless access (BWA). The standard specifies two operational modes, one is popular PMP mode, and the other is optional mesh mode. In the mesh mode, the network entry process-NetEntry is the pivotal procedure for mesh network topology formulation and thus, influences the accessibility of whole mesh network. Unfortunately, the NetEntry process suffers from the hidden neighbor problem, in which new neighborship emerges after a new node comes in and results in possible collisions. In this paper, we propose a new SN-protected NetEntry process to address the problem. Simulation results show that the new proposed NetEntry process is more stable compared with the standard-based NetEntry process.

SN-Protected Network Entry Process for IEEE 802.16 Mesh Network

임립상,유상조,Lixiang, Lin,Yoo, Sang-Jo The Korean Institute of Communications and Informa 2010 韓國通信學會論文誌 Vol.35 No.6b

The workgroup of IEEE 802 proposed the IEEE 802.16 standard, also known as WiMAX, to provide broadband wireless access (BWA). The standard specifies two operational modes, one is popular PMP mode, and the other is optional mesh mode. In the mesh mode, the network entry process-NetEntry is the pivotal procedure for mesh network topology formulation and thus, influences the accessibility of whole mesh network. Unfortunately, the NetEntry process suffers from the hidden neighbor problem, in which new neighborship emerges after a new node comes in and results in possible collisions. In this paper, we propose a new SN-protected NetEntry process to address the problem. Simulation results show that the new proposed NetEntry process is more stable compared with the standard-based NetEntry process.