• Title/Summary/Keyword: carrier selection

Search Result 102, Processing Time 0.02 seconds

사업자 사전 선택제 도입 사례와 시사점

  • 유영상
    • Proceedings of the Korea Technology Innovation Society Conference
    • /
    • 2002.11a
    • /
    • pp.45-57
    • /
    • 2002
  • Since a new entrant in the telecommunications market requires time in order to construct its own network, a requirement on the incumbent operator to implement carrier selection and pre-selection can enable a new entrant to immediately attract customers and earn revenue. Carrier selection can normally be accomplished in two ways, on a call-by-call basis or through carrel pre-selection. Call-by-call selection allows customers to choose a new entrant rather than the incumbent carrier using a specific code designated to the new carrier each time a call is made. Carrier Pre-Selection, on the other hand, allows customers directly connect to the network of one provider to have access automatically to another company's services when they pick up the phone to make certain types of calls. The carrier pre-selection option is generally considered to be a second regulatory step following the implementation of the call-by-call carrier selection option. Carrier pre-selection with the ability to override on a call-by-call basis for long distance, international, local, and fixed-to-mobile calls has now been implemented in many EU countries. This paper attempts to identify the issues in introducing CPS and to draw policy implications from other countries' experiences.

  • PDF

A Study on Performance Enhancement of Selection Combined Hybrid Sequential Deconvolution and SC-FDE for Single Carrier System (선택적 결합 기법을 활용하여 순차적 역컨벌루션과 단일반송파 수신기를 하이브리드하게 사용한 단일반송파 시스템 성능 향상에 관한 연구)

  • Jung, Hyeok-Koo
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.37 no.5A
    • /
    • pp.305-310
    • /
    • 2012
  • This paper proposes a selection combined hybrid sequential deconvolution and single carrier modulation with a zero forcing frequency domain equalizer for single carrier transmission system in order to enhance performance. Selection combining method is an algorithm of antenna space diversities, the receiver can choose the best channel environment only with the increase of the number of antennas, but a baseband structure is the same as the traditional receiver architecture. Simulation results show that the proposed algorithm has a better performance rather than the traditional single carrier transmission with a frequency domain equalizer.

A Carrier Frequency Offset Estimation Algorithm for IEEE802.11n system (IEEE802.11n 시스템에 적용가능한 반송파 주파수 옵셋 추정 알고리즘)

  • Jung, Hyeok-Koo
    • Journal of the Institute of Electronics Engineers of Korea TC
    • /
    • v.45 no.5
    • /
    • pp.21-29
    • /
    • 2008
  • This paper proposes a carrier frequency of set estimation algorithm for IEEE802.11n system. As IEEE802.11n is a multiple input multiple output(MIMO) system, so there are several combining techniques which are used in multiple receive antenna system. In this paper, we propose hybrid carrier frequency offset estimation algorithms using combining techniques in multiple receive antenna systems, and show that the proposed selection combining carrier frequency offset (CFO) estimation algorithm can estimate carrier frequency offset within 1/10 MSE error at SNR 10 dB in channel B and within 1/2 MSE error at SNR 10 dB in channel D rather than the conventional MIMO CFO one.

Research on the PAPR Reduction Method using Selection of Extra Code Set in PB/MC-CDMA System (PB/MC-CDMA 시스템에서 여분의 코드집합을 이용한 PAPR 감쇄기법에 관한 연구)

  • Lee, Kyu-Jin;Lee, Dong-Joon;Lee, Kye-San;Kim, Jin-Young
    • The Journal of The Korea Institute of Intelligent Transport Systems
    • /
    • v.8 no.1
    • /
    • pp.110-118
    • /
    • 2009
  • The PB/MC-CDMA(Partial Block Multi Carrier Code Division Multilple Access) system can improve the performance by reducing the ICI(Inter-Code Interference) between users. Also, this system can achieve the frequency diversity gain by avoiding ISI(Inter Symbol Interference). Therefore, the performance of PB/MC-CDMA system is better than that of conventional MC-CDMA(Multi Carrier Code Division Multiple Access) system. However, similarly to other multi-carrier systems, it still has a PAPR(Peak to Average Power Ratio) issue. In this paper, we propose a peak power reduction technique involving optimized spreading code selection without side information for the PB/MC-CDMA. The PB/MC-CDMA system in each block of units reuses the code so the extra code will be remained. This extra code is divided into several groups to calculate the PAPR and solving the PAPR problem by transferring the selected code which has minimum peak power.

  • PDF

Selection of the Best Oxygen Carrier for Chemical Looping Combustion in a Bubbling Fluidized Bed Reactor (기포유동층에서 케미컬루핑 연소시스템을 위한 최적 산소전달입자 선정)

  • Kim, Hana;Kim, Jung-Hwan;Yoon, Joo-Young;Lee, Doyeon;Baek, Jeom-In;Ryu, Ho-Jung
    • Clean Technology
    • /
    • v.24 no.1
    • /
    • pp.63-69
    • /
    • 2018
  • The reduction reaction characteristics and physicochemical properties were studied for the selection of oxygen carrier, which is the core of the chemical looping combustion (CLC) technology. Fuel conversion and $CO_2$ selectivity of oxygen carrier according to the concentration of reducing gas and the reduction temperature using three kinds of oxygen carrier (SDN70, N018-R2, N016-R4) were measured and compared. In addition, Attrition Index (AI) and BET surface area were measured to analyze the attrition resistance and the surface characteristics of the oxygen carrier. As a result, it was confirmed that all three kinds of oxygen carrier were suitable for use in chemical roofing combustion system, and the best particle was determined to be N016-R4.

Inter-Cell Cooperative Scheduling with Carrier Aggregation in LTE-Advanced System (LTE-Advanced 시스템의 반송파 집성(Carrier Aggregation)을 고려한 셀간 협력 스케쥴링 기법)

  • Yang, Chan S.;Cho, Kumin;Yu, Takki;Kang, Chung G.
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.39B no.3
    • /
    • pp.151-161
    • /
    • 2014
  • 3GPP LTE-Advanced (Release 10) system specifies carrier aggregation (CA) to enable high data rate on using multiple frequency bands, including the variout CA-specific deployment scenarios. Considering one of those scenarios in which the different directional sector antenna is employed by each frequency band, we propose a per-carrier cell selection scheme that can improve the average throughput of the cell-edge users by allowing each user equipment (UE) to select the frequency band of the adjacent cell. Furthermore, a distributed algorithm for inter-cell copperative scheduling in this scheme is proposed to support proportional fairness among the cells. It has been shown that the proposed scheduling algorithm for the per-carrier cell selection scheme improves the cell-edge user throughput roughly by 50% over that of the conventional scheme.

A distributed relay selection algorithm for two-hop wireless body area networks

  • Kim, Seung-Ku;Joo, Yang-Ick
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.41 no.2
    • /
    • pp.156-162
    • /
    • 2017
  • This paper investigates two-hop extension communication in wireless body area networks. Many previous studies have demonstrated that two-hop extended topology outperforms single-hop topology. Although many researchers have proposed using two-hop extension communication to improve link reliability, no one has considered using a relay selection algorithm or provided a suitable solution for wireless body area networks. The design goal of the proposed algorithm is selecting a proper relay node to retransmit failed packets distributively. The proposed algorithm configures the carrier sensing period to choose one relay node promptly without requiring additional interaction. We analyze the link conditions corresponding to various body postures and investigate which factors are proper to determine the carrier sensing period. The empirical results show that the proposed algorithm reduces the expected number of transmissions required to deliver a packet successfully.

Capacity Increasement of Trellis Coded 16 QAM Multi-Carrier CDMA System due to SC/MRC Diversity in Multiuser Interference and Rician Fading Channel.

  • 노재성;강희조;김춘길;김언곤;조성준
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.25 no.3A
    • /
    • pp.362-374
    • /
    • 2000
  • In this paper, trellis coded 16 QAM Multi-Carrior CDMA system is proposed, Using the equivalent signal-to-noise plus interference Power ratio (SNIR) of Multi-Carrier CDMA system in the reverse link, capacity and BER performance of trellis coded 16 QAM Multi-Carrier CDMA system are analyzed taking into account the number of multi-carrier, the number of multiple access user, the number of SC/MRC diversity branch, and Rician fading parameter in multiuser interference and Rician fading channel. And the capacity and the BER performance of trellis coded 16 QAM Multi-Carrier CDMA system using selection combining (SC) and maximal ratio cabining (MRC) diversity are numerically compared. Obtained results show that the capacity of proposed system depends on the number of multi-carrier. ti is found that the trellis coded 16 QAM Multi-Carrier CDMA system with SC/MRC antenna diversity scheme is efficient to combat multipath fading and to increase the maximum number of users in high speed data communication. With the results of analysis. MRC diversity technique provides the performance fro high speed data communications. Finally, we present a numerical approach to derive the capacity and the BER performance and to find the maximum number of multiple access user for Multi-Carrier system in multiuser interference and Rician fading channel.

  • PDF

Market Strategy for Low Cost Carrier of Selection Attributes (저비용항공사 선택 속성에 관한 시장전략)

  • Kim, Ji-Soo;Park, Hye-Yoon;Park, So-Yeon
    • Journal of Distribution Science
    • /
    • v.16 no.3
    • /
    • pp.69-77
    • /
    • 2018
  • Purpose - As more low cost carriers are introduced, the competition between the low cost carriers to become the nation's leading low cost carrier is also being intensified. The purpose of this study is to select various choice attributes for low cost carrier and figure out important factors that customers take into account for low cost carrier selection. The study also involves in establishing the relationship between perceived value, customer satisfaction, and customer behavior Intention, in an effort to identify choice attributes that are important to customers' low cost carrier. Research design, data, and methodology - To examine these research models, samples were collected from 247 peoples who visited In-Cheon international Airport during June, 2017. Results - The results of the study showed that, 'reservation service', 'airport service', 'in-flight service', and 'price' services have a significant effect on the perceived value of the choice attributes. While 'reservation service', 'airport service', 'in-flight service', and 'flight operation service' have a significant effect on the customer satisfaction of the choice attributes, perceived value has a significant effect on customer satisfaction. Perceived value has a significant effect on customer behavior intention. Finally, customer satisfaction has a significant effect on customer behavior intention. Conclusions - Flight operation service has no significant effect on perceived value of the choice attributes of low cost carriers, which indicates that the low cost carriers have not yet been well-established in the flight operation service sector. It seems likely that low cost carrier will be able to gain a competitive advantage over other companies if they expand their routes and improve the convenience of flight connections. In addition, the results show that the price service does not have a significant effect on customer satisfaction of the choice attributes of low cost carriers. From this, we may assume that the airline ticket prices of low cost carriers are already low, and the price cannot be a deciding factor in the competitive advantage of low cost carriers. To achieve higher customer satisfaction of the choice attributes, companies should strengthen the competitiveness of 'reservation service', 'airport service', 'in-flight service', and 'flight operation service'.

Design of a simple closed-loop Transmit Diversity Scheme Using Sub-carrier Grouping for ECMA-392 Systems (ECMA-392 시스템을 위한 부 반송파 그룹핑 기반 폐루프 전송 다이버시티 기법 설계)

  • Joo, Jung Suk
    • Journal of the Institute of Electronics and Information Engineers
    • /
    • v.51 no.4
    • /
    • pp.3-9
    • /
    • 2014
  • ECMA-392 is the first cognitive radio (CR) specification for personal/portable devices in TV white space. It supports two transmit antennas, for which only open-loop transmit diversity schemes are included. In this paper, we design a simple closed-loop transmit diversity scheme using sub-carrier grouping for ECMA-392 systems. First, sub-carrier grouping types suitable for ECMA-392 systems are described, and then a transmit antenna selection scheme is proposed. In order to reduce feedback information, decision on the transmit antenna selection in the given channel environments is made at the receiver side and the only index of the decided transmit antenna is sent to the transmit side. Through performance comparison to open-loop transmit diversity schemes of ECMA-392, it will be shown that with only a slight feedback overhead, the proposed scheme can improve receiver performance of ECMA-392 systems.