A dual-path high linear amplifier for carrier aggregation

Kang, Dong-Woo,Choi, Jang-Hong Electronics and Telecommunications Research Instit 2020 ETRI Journal Vol.42 No.5

A 40 nm complementary metal oxide semiconductor carrier-aggregated drive amplifier with high linearity is presented for sub-GHz Internet of Things applications. The proposed drive amplifier consists of two high linear amplifiers, which are composed of five differential cascode cells. Carrier aggregation can be achieved by switching on both the driver amplifiers simultaneously and combining the two independent signals in the current mode. The common gate bias of the cascode cells is selected to maximize the output 1 dB compression point (P1dB) to support high-linear wideband applications, and is used for the local supply voltage of digital circuitry for gain control. The proposed circuit achieved an output P1dB of 10.7 dBm with over 22.8 dBm of output 3rd-order intercept point up to 0.9 GHz and demonstrated a 55 dBc adjacent channel leakage ratio (ACLR) for the 802.11af with -5 dBm channel power. To the best of our knowledge, this is the first demonstration of the wideband carrier-aggregated drive amplifier that achieves the highest ACLR performance.

Water-Soluble Fluorinated and PEGylated Cyanostilbene Derivative: An Amphiphilic Building Block Forming Self-Assembled Organic Nanorods with Enhanced Fluorescence Emission

Shin, Seunghoon,Gihm, Se Hoon,Park, Chong Rae,Kim, Sehoon,Park, Soo Young American Chemical Society 2013 Chemistry of materials Vol.25 No.16

<P>We report synthesis and optical/structural characterization of new fluorescent rod–coil amphiphiles based on the PEGylated α-cyanostilbene skeleton (12EO-CNMBE and 12EO-CNTFMBE) and their self-assembly behaviors in water. Distinct from the common amphiphilic behavior of nonfluorinated 12EO-CNMBE forming spherical nanostructures, fluorinated 12EO-CNTFMBE has proven to be the first example of a molecular building block that can self-assemble in water into small-dimension, small-aspect-ratio organic nanorods with aggregation-induced enhanced emission (AIEE). The robust structural integrity and hydrophobic/π-conjugated nature of the fluorinated block assembly, as well as the antifouling coating by the hydrophilic PEG block, enabled stable encapsulation of a model drug (Nile Red) within the self-assembled nanorod structure and its successful delivery through membrane filters. By virtue of these advantageous attributes along with high intracellular uptake efficiency, the 12EO-CNTFMBE nanorods manifested potential as a self-signaling fluorescent nanocarrier for the intracellular delivery of hydrophobic cargos.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/cmatex/2013/cmatex.2013.25.issue-16/cm400988a/production/images/medium/cm-2013-00988a_0010.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/cm400988a'>ACS Electronic Supporting Info</A></P>

3차원 주파수 재사용 패턴의 성능 및 반송파 결합을 사용하는 시스템으로의 적용 방안

성지훈(Jihoon Sung),성원진(Wonjin Sung) 한국전자파학회 2012 한국전자파학회논문지 Vol.23 No.11

셀룰러 이동통신의 주요 성능 열화 요인으로 작용하는 셀 간 간섭을 제어하기 위하여, 인접한 셀 간에 주파수 자원을 선택적으로 할당하는 주파수 재사용 기법을 활용할 수 있다. 기존의 주파수 재사용 패턴에 대한 연구는 주로 2차원 공간에 제한되어 있었기 때문에, 도심 지역의 사무용 빌딩과 같이 사용자가 밀집된 지역에 설치된 펨토셀에 적용하기 위해서는 3차원 공간에서의 주파수 재사용 방식에 대한 연구가 필요하다. 본 논문에서는 3차원 공간에서 사용 가능한 주파수 패턴들을 제안하고, 각 패턴별 성능을 채널 용량 측면에서 분석한다. 특히, LTEAdvanced 시스템의 요소 반송파 결합 기술을 고려시 제안 방식의 적용을 통해 보다 유연한 3차원 주파수 재사용 패턴을 생성할 수 있음을 보이고, 시뮬레이션을 통해 제안 방식의 성능을 평가한다. Assigning different frequency resources among adjacent cells, namely the frequency reuse technique can be utilized to mitigate intercell interference, which is a major cause of performance degradation in cellular systems. Since most of conventional frequency reuse patterns are limited to the two-dimensional environment, the research for the three-dimensional frequency reuse would be beneficial especially for the implementation of femto cells in downtown office buildings. We propose frequency reuse patterns in three-dimensional space and evaluate their performance of each pattern in terms of channel capacity. In particular, we show that the proposed three-dimensional frequency reuse patterns can be applied for carrier-aggregated transmission of LTE-Advanced systems. The performance of the proposed patterns is evaluated using computer simulation.

Wider Bandwidth of non-Contiguous Component Carriers in LTE-Advanced

Aws Zuheer Yonis,Mohammad Faiz Liew Abdullah 보안공학연구지원센터 2013 International Journal of Future Generation Communi Vol.6 No.2

Performance evaluation of Downlink Non Contiguous Carrier Aggregation in LTE-A

Diksha Duggal,Jyoteesh Malhotra,Khushboo Arora 보안공학연구지원센터 2015 International Journal of Signal Processing, Image Vol.8 No.9

Long Term Evolution-Advanced (LTE-A) has brought revolution in the field of wireless communication technology by providing high data rates of up to 1Gbps. One key enhancement feature of LTE-A is bandwidth extension by the use of multi-carrier technology to support deployment bandwidth of up to 100MHz. To achieve such high data rate in IMT-Advanced mobile systems, carrier aggregation technology by 3GPP has been introduced to support very-high-data rate transmissions over wide frequency bandwidth in the new LTE-Advanced standards. This work includes the details of Downlink LTE Advanced System Model and thereby all the performance analysis of Non Contiguous Carrier Aggregation are done and an overview of LTE-Advanced CA scenarios is discussed. Also component carrier parameters and oversampling factor are found and using these parameters power spectrum is plotted. The main outcome from this work is increase in the throughput of the system by increasing the number of carrier components or by increasing bandwidth. Many proposals on carrier aggregation in LTE-A have been published but still there is a need of research to be carried out in this field as this technology has not fully matured.

Effective Beamforming Technique for Carrier Aggregation of Millimeter Wave

김태경 사단법인 미래융합기술연구학회 2019 아시아태평양융합연구교류논문지 Vol.5 No.1

This paper proposes an effective beamforming technique for carrier aggregation of millimeter wave. Millimeter wave exploits a high center frequency that results in a large path loss. To overcome this large path loss, analog beamforming was introduced using a phase shifter. Analog beamforming can be extended to the carrier aggregation system that is composed of a primary carrier component (PCC) and secondary carrier component (SCC). Generally, each carrier component has its radio frequency (RF) chain so that beamforming is independently performed. However, the expense of a millimeter RF chain is extremely high. Thus, it limits the number of RF chains in the terminal. To address this problem, this paper proposes an effective beam selection method that involves sharing of the RF chain by the carrier component. Performance of the PCC should be guaranteed because the PCC conveys an important system parameter to the terminal. The beam selection problem is first designed considering this constraint, followed by proposing an effective solution to the problem. This study investigates the effectiveness of the proposed method in terms of throughput and complexity. Simulations show that the proposed solution provides higher throughput than the conventional PCC-based method while the throughput of PCC is guaranteed.

Distributed Carrier Aggregation in Small Cell Networks: A Game-theoretic Approach

( Yuanhui Zhang ),( Chunrong Kan ),( Kun Xu ),( Yuhua Xu ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.12

In this paper, we investigate the problem of achieving global optimization for distributed carrier aggregation (CA) in small cell networks, using a game theoretic solution. To cope with the local interference and the distinct cost of intra-band and inter-band CA, we propose a non-cooperation game which is proved as an exact potential game. Furthermore, we propose a spatial adaptive play learning algorithm with heterogeneous learning parameters to converge towards NE of the game. In this algorithm, heterogeneous learning parameters are introduced to accelerate the convergence speed. It is shown that with the proposed game-theoretic approach, global optimization is achieved with local information exchange. Simulation results validate the effectivity of the proposed game-theoretic CA approach.

Development of Recycled Aggregate Bio-carrier with Sulfate Reducing Bacteria for the Elimination of Heavy Metals from Seawater

Kim, In Hwa,Lee, Won-Jin,Kim, Young-Kee,Oh, Byung-Keun Korean Society for Biotechnology and Bioengineerin 2016 Biotechnology and Bioprocess Engineering Vol.21 No.5

In this study, we fabricated a novel recycled aggregate (RA) bio-carrier with sulfate-reducing bacteria (SRB) for the effective removal of the heavy metals <TEX>$Zn^{2+}$</TEX>, <TEX>$Ni^{2+}$</TEX>, and <TEX>$Cr^{6+}$</TEX> from contaminated seawater. By using only RA carriers, <TEX>$Zn^{2+}$</TEX>, <TEX>$Ni^{2+}$</TEX>, and <TEX>$Cr^{6+}$</TEX> could be removed up to 35.6, 11.0, and 61.3% and SRB-immobilized RA bio-carriers could effectively lead to the removal of <TEX>$Zn^{2+}$</TEX>, <TEX>$Ni^{2+}$</TEX>, and <TEX>$Cr^{6+}$</TEX> up to 100.0, 98.0, and 87.8% for 100 ppm concentration of the heavy metals at <TEX>$37^{\circ}C$</TEX>, respectively. These results indicate that recycled aggregate bio-carriers with SRB hold great potential for use in the removal of cationic heavy metal species from marine environment.

LTE-Advanced 시스템의 반송파 집성(Carrier Aggregation)을 고려한 셀간 협력 스케쥴링 기법

양찬석(Chan S. Yang),조구민(Kumin Cho),류탁기(Takki Yu),강충구(Chung G. Kang) 한국통신학회 2014 韓國通信學會論文誌 Vol.39 No.3(네트워크)

3GPP LTE-Advanced 시스템(Release 10)의 Carrier Aggregation (CA) 규격은 고속의 전송률을 지원하기 위해 다수의 주파수 밴드를 통합하면서, 이를 고려한 다양한 배치 시나리오를 제시하고 있다. 본 논문에서는 각 주파수 밴드 별로 상이한 방향성 섹터 안테나를 사용하는 배치 시나리오를 고려하며, 이때 단말이 인접 셀의 주파수 밴드를 선택 가능하게 함으로써 셀 경계 사용자의 수율 성능을 향상할 수 있는 셀 선택 방식을 제안한다. 그리고 이러한 방식 하에 셀 간에 비례공정성(proportional fairness)이 확보될 수 있도록 하는 분산 방식의 셀간 협력 스케쥴링 알고리즘을 제시하며, 이를 통해 기존 방식보다 셀 경계 사용자의 수율이 약 50% 향상되는 것을 확인한다. 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.

CA Joint Resource Allocation Algorithm Based on QoE Weight

( Liu Jun-xia ),( Jia Zhen-hong ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.5

For the problem of cross-layer joint resource allocation (JRA) in the Long-Term Evolution (LTE)-Advanced standard using carrier aggregation (CA) technology, it is difficult to obtain the optimal resource allocation scheme. This paper proposes a joint resource allocation algorithm based on the weights of user’s average quality of experience (JRA-WQOE). In contrast to prevalent algorithms, the proposed method can satisfy the carrier aggregation abilities of different users and consider user fairness. An optimization model is established by considering the user quality of experience (QoE) with the aim of maximizing the total user rate. In this model, user QoE is quantified by the mean opinion score (MOS) model, where the average MOS value of users is defined as the weight factor of the optimization model. The JRA-WQOE algorithm consists of the iteration of two algorithms, a component carrier (CC) and resource block (RB) allocation algorithm called DABC-CCRBA and a subgradient power allocation algorithm called SPA. The former is used to dynamically allocate CC and RB for users with different carrier aggregation capacities, and the latter, which is based on the Lagrangian dual method, is used to optimize the power allocation process. Simulation results showed that the proposed JRA-WQOE algorithm has low computational complexity and fast convergence. Compared with existing algorithms, it affords obvious advantages such as improving the average throughput and fairness to users. With varying numbers of users and signal-to-noise ratios (SNRs), the proposed algorithm achieved higher average QoE values than prevalent algorithms.