Performance of ZF Precoder in Downlink Massive MIMO with Non-Uniform User Distribution

Chuili Kong,Caijun Zhong,Zhaoyang Zhang 한국통신학회 2016 Journal of communications and networks Vol.18 No.5

In this paper, we investigate the achievable sum rateand energy efficiency of downlinkmassive multiple-inputmultiple-output antenna systems with zero-forcing precoding, by taking intoaccount the randomness of user locations. Specifically, we pro-pose two types of non-uniform user distributions, namely, center-intensive user distribution and edge-intensive user distribution. Based on these user distributions, we derive novel tight lower andupper bounds on the average sum rate. In addition, the impact ofuser distributions on the optimal number of users maximizing thesum rate is characterized. Moreover, by adopting a realistic powerconsumption model which accounts for the transmit power, circuitpower and signal processing power, the energy efficiency of the sys-tem is studied. In particular, closed-form solutions for the key sys-tem parameters, such as the number of antennas and the optimaltransmit signal-to-noise ratio maximizing the energy efficiency, areobtained. The findings of the paper suggest that user distributionhas a significant impact on the system performance: for instance,the highest average sum rate is achieved with the center-intensiveuser distribution, while the lowest average sum rate is obtainedwith the edge-intensive user distribution. Also, more users can beserved with the center-intensive user distribution.

Performance of ZF Precoder in Downlink Massive MIMO with Non-Uniform User Distribution

Kong, Chuili,Zhong, Caijun,Zhang, Zhaoyang The Korea Institute of Information and Commucation 2016 Journal of communications and networks Vol.18 No.5

In this paper, we investigate the achievable sum rate and energy efficiency of downlink massive multiple-input multiple-output antenna systems with zero-forcing precoding, by taking into account the randomness of user locations. Specifically, we propose two types of non-uniform user distributions, namely, center-intensive user distribution and edge-intensive user distribution. Based on these user distributions, we derive novel tight lower and upper bounds on the average sum rate. In addition, the impact of user distributions on the optimal number of users maximizing the sum rate is characterized. Moreover, by adopting a realistic power consumption model which accounts for the transmit power, circuit power and signal processing power, the energy efficiency of the system is studied. In particular, closed-form solutions for the key system parameters, such as the number of antennas and the optimal transmit signal-to-noise ratio maximizing the energy efficiency, are obtained. The findings of the paper suggest that user distribution has a significant impact on the system performance: for instance, the highest average sum rate is achieved with the center-intensive user distribution, while the lowest average sum rate is obtained with the edge-intensive user distribution. Also, more users can be served with the center-intensive user distribution.

Attribute based User Authentication for Contents Distribution Environments

유혜정 한국콘텐츠학회 2012 International Journal of Contents Vol.8 No.3

In digital contents distribution environments, a user authentication is an important security primitive to allow only authenticated user to use right services by checking the validity of membership. For example, in Internet Protocol Television (IPTV) environments, it is required to provide an access control according to the policy of content provider. Remote user authentication and key agreement scheme is used to validate the contents accessibility of a user. We propose a novel user authentication scheme using smart cards providing a secure access to multimedia contents service. Each user is authenticated using a subset of attributes which are issued in the registration phase without revealing individual’s identity. Our scheme provides the anonymous authentication and the various permissions according to the combination of attributes which are assigned to each user. In spite of more functionality, the result of performance analysis shows that the computation and communication cost is very low. Using this scheme, the security of contents distribution environments in the client-server model can be significantly improved.

Attribute based User Authentication for Contents Distribution Environments

Hyejoung Yoo 한국콘텐츠학회(IJOC) 2012 International Journal of Contents Vol.8 No.3

In digital contents distribution environments, a user authentication is an important security primitive to allow only authenticated user to use right services by checking the validity of membership. For example, in Internet Protocol Television (IPTV) environments, it is required to provide an access control according to the policy of content provider. Remote user authentication and key agreement scheme is used to validate the contents accessibility of a user. We propose a novel user authentication scheme using smart cards providing a secure access to multimedia contents service. Each user is authenticated using a subset of attributes which are issued in the registration phase without revealing individual’s identity. Our scheme provides the anonymous authentication and the various permissions according to the combination of attributes which are assigned to each user. In spite of more functionality, the result of performance analysis shows that the computation and communication cost is very low. Using this scheme, the security of contents distribution environments in the client-server model can be significantly improved.

User Hot Spots of Urban Parks Identified Using Mobile Signaling Data - A Case Study of Seongdong-Gu, Seoul -

조민균,박찬,서자유,최혜영 한국조경학회 2023 韓國造景學會誌 Vol.51 No.3

This study investigated the distribution of users in urban parks to overcome the limitations of existing research, which made it difficult to determine where data came was collected. It aimed to provide implications for park planning and management based on user distribution using mobile signal data. Five urban parks in Seongdong-gu, Seoul, with various physical characteristics, were selected. Mobile signal data provided by the Seoul Big Data Campus was used to identify the distribution of user inflow through hot spot analysis per park. The relationship between urban context and park influence area was derived. Seoul Forest (P1) and Seongsu Park (P3), which have a high proportion of commercial spaces around the park, showed wider user hotspots compared to Eungbong Park (P2), Dokseodang Park (P4), and Daehyunsan Park (P5), which were located in residential areas. Parks with a significant presence of commercial spaces had a broader influence, while parks with larger sizes and gentle slopes exhibited wider influence areas. This study proposed a novel data-based approach to urban park planning and management based on the inflow distribution of park users. Through this research, valuable insights were derived that could be utilized for urban park planning and management, aiming to enhance the effectiveness and efficiency of park utilization.

Attribute based User Authentication for Contents Distribution Environments

Yoo, Hye-Joung The Korea Contents Association 2012 International Journal of Contents Vol.8 No.3

In digital contents distribution environments, a user authentication is an important security primitive to allow only authenticated user to use right services by checking the validity of membership. For example, in Internet Protocol Television (IPTV) environments, it is required to provide an access control according to the policy of content provider. Remote user authentication and key agreement scheme is used to validate the contents accessibility of a user. We propose a novel user authentication scheme using smart cards providing a secure access to multimedia contents service. Each user is authenticated using a subset of attributes which are issued in the registration phase without revealing individual's identity. Our scheme provides the anonymous authentication and the various permissions according to the combination of attributes which are assigned to each user. In spite of more functionality, the result of performance analysis shows that the computation and communication cost is very low. Using this scheme, the security of contents distribution environments in the client-server model can be significantly improved.

User Responses Towards Information Distribution of Copyright Law No. 28 of 2014 Concerning Permits for Commercial Use of Music Performing Rights

Naufal MUHIDIASTU,La MANI,Fariz Ubaidillah RASYID,Hanan ZHAFIRAH,Muhammad ARAS 한국유통과학회 2022 유통과학연구 Vol.20 No.1

Purpose: This article discusses public acceptance in the information distribution of Copyright Law no. 28 of 2014 and Government Regulation No. 56 of 2021 in Indonesia concerning the commercial use of music. Hospitality industry is one of the most affected by this regulations, which some hotels refused to comply. To get royalties, LMKN approaches with socialization either directly or indirectly to commercial music users. Research design, data and methodology: Quantitative survey by distributing questionnaires, then testing the validity and reliability tests using the SmartPLS application. The population studied were Hotels on Java and Bali Island in Indonesia. The research sample is 100 hotels. Result: R-Square value of 0.706 for the construct (Y) User Response which means that (X) Socialization can explain the variance (Y) User Response of 70.3%. This shows that the level of influence (X) Socialization has an effect on (Y) User Response. Conclusion: User responses regarding the distribution information of the Act indicate the need for socialization, because socialization provides literacy to the public. More frequent socialization will provide a good opportunity to increase the response of commercial music users.

Empirical Analysis of User Interaction Behavior in Microblogging

WeiGuo Yuan,Yun Liu,JingJing Yang 한국산학기술학회 2012 SmartCR Vol.2 No.3

Patterns of user interaction behavior in online social networks have attracted increasing academic interest, since the quantitative understanding of user behavior is helpful to uncover the origins of many socioeconomic phenomena. In order to gain insights into user interaction behavior characteristics in microblogging, we have crawled Sina Microblog data and obtained user profiles and statuses. Six features of users are studied in our experiments, which are followers and friends, statuses and favorites, retweets and comments. Empirical analysis reveals some common statistical features of user behavior in microblogging. First, all of these properties follow different power-law distributions. Especially, followers and statuses exhibit a double-power-law distribution and friends follow a specific interval power law distribution. Second, there exists a strong positive correlation between statuses and followers, retweets and comments, but the relation between followers and friends is weak. What"s more, there exists a moderate correlation between the number of friends and statuses, retweets and followers, and comments and followers. Third, only a small number of statuses have extreme dissemination and concern. From a quantitative view, the result shows that the strong effect of celebrity cannot be ignored in Sina Microblogs. We believe this paper has added rich empirical materials to our knowledge and understanding of user behavior in microblogging.

Distributed Fronthaul-Constrained Joint Transmission Design and Selection Using Augmented Consensus-based Dual Decomposition

Mykola Servetnyk,Carrson C. Fung 한국통신학회 2022 Journal of communications and networks Vol.24 No.4

User-centric coordinated multipoint (CoMP) joint transmission (JT) is a novel technique to manage interference and enhance system performance with single frequency reuse, where user equipment (UE) communicates with their closest transmission points (TPs). Unfortunately, in coherent JT, requirement of strict network synchronization accuracy makes it difficult and expensive to be practically deployed. The noncoherent JT has therefore received growing attention since it requires less strict network synchronization accuracy compared to its coherent counterpart as it does not require the signal to be phase-aligned at the receiver. Moreover, cell-free massive MIMO, which is regarded as combining CoMP with massive MIMO systems, has recently been touted as a solution for avoiding intercell interference and provide uniform coverage over a large area. However, the operational costs of CoMP, such as the associated control signaling and communication overhead and the increase of network complexity, could prevent the practical implementation of CoMP. A distributed joint transmission CoMP (JT-CoMP) scheme is proposed herein that allows distributed design and selection of cooperating transmission nodes. To maximize user capacity, the proposed distributed consensus optimization problem assumes spectrum underlay transmission is used so that the solution can achieve non-orthogonal multiple access (NOMA) for cell-free user centric JT-CoMP systems. The proposed algorithm is different from others in the literature because it solves a design problem that involves a coupling constraint that no existing algorithm can solve. Analytical results based on spectral graph theory are given to prove its convergence and characterize its rate of convergence. The more practical scenario is further considered, where limited fronthaul capacity is also included in the problem. A successive convex approximation (SCA) method is used to solve the resulting nonconvex problem, which is shown to maximize spectral efficiency. Simulation results are provided to show that the performance of both proposed distributed algorithms (that address problem without and with fronthaul constraint) is comparable to its centralized counterpart.

관련성 분포정보를 이용한 사용자 선호도 추천시스템

김현주,이광석 한국지식정보기술학회 2010 한국지식정보기술학회 논문지 Vol.5 No.5

By using wireless communication which is developed, there has been an active electronic commerce. Not like the server's mechanical reactions inside the electronic commerce's form, it is one of the important factor to make a friendly relations from the users service. So in this essay, by using wireless communication inside the electronic commerce, user's dispatcher imforms reducing scale. By evaluating these things, we will develop real-time supportings to the users which is 'Friendly User as Information Monitoring System : FUIS'.