This paper proposes two interference mitigation strategies that adjust the maximum transmit power of femtocell users to suppress cross-tier at a macrocell base station (BS). The open-loop and closed-loop control less than fixed threshold an adaptive based on noise (NI) level BS, respectively. Simulation results show both schemes effectively compensate uplink throughput degradation BS due provides better minimal cost throughput.

This paper proposes a self-optimized coverage coordination scheme for two-tier femtocell networks, in which base station adjusts the transmit power based on statistics of signal and interference that is measured at downlink. Furthermore, an analytic expression derived leakage probability area leaks into outdoor macrocell. The analysis verified by simulation, shows proposed provides sufficient indoor does not leak

In this paper, the reverse-link interrogation range (RIR) of ultrahigh-frequency-band passive radio-frequency identification (RFID) is analyzed for single-input and single-output (SISO) multiple-input multiple-output (MIMO) systems with maximal-ratio combining in pinhole channel, where each channel modeled as an arbitrarily correlated Nakagami-m distribution. Under assumptions perfect estimation no interference, closed-form expression average RIR derived, involving various parameters, such...

Distributed congestion control (DCC) improves system performance by lowering channel in vehicular environments with high vehicle density. The 3rd Generation Partnership Project standard defines the related metrics of busy ratio (CBR) and introduces possible rate power mechanisms to mitigate cellular vehicle-to-everything (C-V2X) sidelink. However, DCC C-V2X is not sufficiently specified implement these controls. In this letter, we propose a novel algorithm based on deep reinforcement...

In this paper, we propose a time and frequency domain channel estimation scheme, which is based on the interpolation of reliable data pilots obtained from domain, for IEEE 802.11p standard. A number estimates are selected through reliability test initial estimates, then they interpolated in to recover at unreliable subcarriers. Due correlation between adjacent subcarriers, can provide better pilots. Furthermore, proposed scheme exploit four comb interpolation, improves accuracy carriers...

This paper proposes two interference mitigation strategies that adjust the maximum transmit power of femtocell users to suppress cross-tier at a macrocell base station (BS). The open-loop and closed-loop control less than fixed threshold an adaptive based on noise (NI) level BS, respectively. Simulation results show both schemes effectively compensate uplink throughput degradation BS provides better minimal cost throughput.

This letter provides an analysis of the interaction between cooperative diversity and multiuser in downlink channels. Through approximation signal-to-noise ratio (SNR) distribution each link using gamma distribution, we can derive analytic expression for average throughput a single-cell wireless system with multiple links combined fair-access scheduler. The proposed approach is verified through comparisons simulated results shows that has detrimental impact on diversity.

This paper analyzes the effects of polarization-mismatch and space-correlation to a multiple-input single-output (MISO) channel which is observable in near future cellular communications environments such as large-scale antenna arrays small cells. The analysis based on polarization-mismatched space-correlated MISO modeled from conventional dual-polarized channel. In channel, described by angle uniformly distributed 0 maximum exponential correlation model. Assuming high SNR, approximate...

Expressions for the average channel capacity of a multiuser diversity system combined with transmit at each link are presented under assumption independent Rayleigh fading. The analysis results exactly agree simulation and definitely show impact on diversity.

Recently, research into autonomous driving and traffic safety has been drawing a great deal of attention. To realize solve problems, wireless access in vehicular environments (WAVE) technology developed, IEEE 802.11p defines the physical (PHY) layer medium control (MAC) WAVE standard. However, frame structure, which low pilot density, makes it difficult to predict properties channels environment with high vehicle speeds; thus, performance system is degraded realistic environments. The...

This letter proposes a low-complexity algorithm for transmit-antenna selection in multi-input multi-output spatial multiplexing system with per-antenna rate control and an ordered successive interference cancellation receiver. The active antenna subset its transmission are determined at the receiver, conveyed to transmitter using limited feedback. We propose serial antenna-selection procedure consisting of process that tests whether gain exists when lowest signal-to-interference-plus-noise...

An approximated probability density function is presented for the SNR in maximal ratio combining diversity systems with an arbitrary number of branches arbitrarily correlated Nakagami fading environment. Comparisons between exact and distribution show good agreement over wide ranges correlation coefficients.

In order to support the mobility of vehicles and reliable services in Institute Electrical Electronics Engineers (IEEE) 802.11p/wireless access vehicular environments (WAVE) network, cell planning coverage optimization are critical issues. light this, we employed IEEE 802.11p/WAVE test-bed located at Chungju campus Korea National University Transportation (KNUT). We proposed a prediction model by using 3D ray-tracing tool with geographic information system (GIS) data for optimization....

A minimum mean square error estimation (MMSE) using a virtual pilot channel scheme was proposed by our researchers for improving the performance of IEEE 802.11p. However, compared to STA scheme, MMSE cannot provide an acceptable in low SNR region. To alleviate this, we propose adaptive which selectively uses that has in-between and MMSE, through decision method long preamble. Simulation results demonstrate can select better thereby demonstrating excellent over entire range interest.

Due to the significant increase in use of autonomous car technology, it is essential integrate this technology with high-precision digital map data containing more precise and accurate roadway information, as compared existing conventional resources, ensure safety self-driving operations.While technologies may assist vehicles identifying their locations via Global Positioning System, however difficult update environmental changes roadways these maps.Roadway vision algorithms can be useful...

This work presents a quasi-three dimensional MIMO channel model to predict the polarization characteristics of an indoor radio channel. The considers not only effects transmitting and receiving antenna elements, but also types environment scatterers. proposed is based on ellipse patch scattering model. Furthermore, expands suitable for channels can expect ergodic capacities multi-polarized channel, which 3-D geometry

In this paper, for spatial multiplexing with limited feedback, a quantized principal component selection (QPCS) precoding scheme is proposed that achieves comparable capacity to the closed-loop multiple-input multiple-output (MIMO) and furthermore adapts various fading channel conditions without any additional feedback bits transmit state information (CSI). We propose systematic design method codebook consisting of finite number unitary matrices based on maximizing minimum distance criterion...

본 논문에서는 massive MIMO(Multiple-Input Multiple-Output) 시스템의 채널 특성 분석을 위해, 3차원 레이트레이싱 기반 무선 시뮬레이터인 Wireless Insite를 이용하여, 마이크로셀 환경에서 수평으로 선형 배열된 4개와 128개의 이중 편파 안테나 (dual polarized antenna)로 구성된 송신 배열 각도 확산(angular spread), 교차 식별도(cross polarization discrimination, XPD), 그리고 지연 확산(delay spread) 특성을 비교 분석하였다. 시뮬레이션 및 통해 원소로 MIMO 각도확산과 확산은 4개의 시스템 보다 작아지고 식별도는 커진다는 것을 확인하였다. In this paper, wireless channel characteristics of system is analyzed by comparing angular spread, cross...

본 논문에서는 IEEE 802.11p 통신 시스템 성능을 향상시킬 수 있는 가상 기준신호(virtual pilot)를 사용하는 MMSE(minimum mean square error) 채널 추정 기법을 제안한다. 제안하는 기법은 기준신호 부반송파 사이에 위치하는 약속된 데이터 부반송파, 즉 부반송파에서 수신되는 심볼을 이용하여 초기 추정치와 추정치를 기반으로 하는 주파수 영역 상관행렬을 구하고, 이를 MMSE기법을 수행한다. 기법이 선택적 페이딩 환경에서 부반송파를 사용하여 영역에서의 간격을 감소시킴으로서, 추가적인 복잡도가 낮지만 효과적으로 개선함을 시뮬레이션을 통해 증명한다.

In this paper, we propose bicycle collision avoidance (BCA) algorithms and analyze their performance. As typical type accidents related with bicycles, consider both intersection rear crash. Then, the crash (RCA) algorithm (ICA) are respectively developed by utilizing 'PreScan' 'MATLAB'. The derived analytical approach can explain condition effect of collisions. Furthermore, proposed verified from simulations. Consequently, BCA developing methodology is confirmed to be used as a general...

This paper proposes a space-polarization division multiple access (SPDMA) system that has limited feedback channels.The simultaneously serves data streams to mobile users through dual-polarized antenna arrays, by using pre-determined sets of precoding vectors are orthogonal in both space and polarization domains.To this end, codebook whose elements the is systematically designed based on discrete Fourier transform (DFT) matrix considering power imbalance polarized channels.Throughput SPDMA...

Distributed congestion control (DCC) is a representative algorithm for improving the performance of Cellular-V2X (C-V2X) in dense vehicle scenarios. Since existing DCC algorithms are not designed to respond target value Quality Service (QoS) parameter adaptively, they can improve communication some extent but do guarantee achievement value. To solve this problem, we propose deep Q network (DQN)-based QoS adaptive C-V2X Vehicle (V2V) communication. In particular, considering limitations V2V...

The bit error rate (BER) performance and the characteristics of a two-dimensional (2-D) RAKE receiver operating in correlated frequency-selective Nakagami-fading environment are analyzed. Correlated fading between array elements whose statistics identical across same branch, as well an arbitrary number RAKE-branches with finding statistics, assumed. We derived approximated signal-to-noise ratio (SNR) for one branch multiple antennas, which is extended to that branches i.e., 2-D receiver....