scholarly journals An Adaptive Measurement Report Period and Handoff Threshold Scheme Based on SINR Variation in LTE-A Networks

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Jenhui Chen ◽  
Ching-Yang Sheng
Keyword(s):  
Decision Making ◽  
Reference Signal ◽  
Critical Parameters ◽  
Threshold Scheme ◽  
Term Evolution ◽  
Ping Pong ◽  
Adaptive Measurement ◽  
Simulation Results ◽  
Unnecessary Handoff

This paper deals with the problem of triggering handoff procedure at an appropriate point of time to reduce the ping-pong effect problem in the long-term evolution advanced (LTE-A) network. In the meantime, we also have studied a dynamic handoff threshold scheme, named adaptive measurement report period and handoff threshold (AMPHT), based on the user equipment’s (UE’s) reference signal received quality (RSRQ) variation and the moving velocity of UE. AMPHT reduces the probability of unnecessarily premature handoff decision making and also avoids the problem of handoff failure due to too late handoff decision making when the moving velocity of UE is high. AMPHT is achieved by two critical parameters: (1) a dynamic RSRQ threshold for handoff making; (2) a dynamic interval of time for the UE’s RSRQ reporting. The performance of AMPHT is validated by comparing numerical experiments (MATLAB tool) with simulation results (the ns-3 LENA module). Our experiments show that AMPHT reduces the premature handoff probability by 34% at most in a low moving velocity and reduces the handoff failure probability by 25% in a high moving velocity. Additionally, AMPHT can reduce a large number of unnecessary handoff overheads and can be easily implemented because it uses the original control messages of 3GPP E-UTRA.

scholarly journals Co-Channel Interference Suppression for LTE Passive Radar Based on Spatial Feature Cognition

Sensors ◽  
2021 ◽  
Vol 22 (1) ◽  
pp. 117
Author(s):  
Haitao Wang ◽  
Xiaoyong Lyu ◽  
Kefei Liao
Keyword(s):  
Interference Suppression ◽  
Reference Signal ◽  
Spatial Spectrum ◽  
Base Station ◽  
Base Stations ◽  
Passive Radar ◽  
Term Evolution ◽  
Reference Signals ◽  
Simulation Results

Passive radars based on long-term evolution (LTE) signals suffer from sever interferences. The interferences are not only from the base station used as the illuminator of opportunity (BS-IoO), but also from the other co-channel base stations (CCBS) working at the same frequency with the BS-IoO. Because the reference signals of the co-channel interferences are difficult to obtain, cancellation performance degrades seriously when traditional interference suppression methods are applied in LTE-based passive radar. This paper proposes a cascaded cancellation method based on the spatial spectrum cognition of interference. It consists of several cancellation loops. In each loop, the spatial spectrum of strong interferences is first recognized by using the cyclostationary characteristic of LTE signal and the compressed sensing technique. A clean reference signal of each interference is then reconstructed according to the spatial spectrum previously obtained. With the reference signal, the interferences are cancelled. At the end of each loop, the energy of the interference residual is estimated. If the interference residual is still strong, then the cancellation loop continues; otherwise it terminates. The proposed method can get good cancellation performance with a small-sized antenna array. Theoretical and simulation results demonstrate the effectiveness of the proposed method.

scholarly journals Eficiencia de sistemas multiantena MU–MIMO por simulaciones de radiopropagación

2017 ◽  
Vol 11 (1) ◽  
pp. 55-62
Author(s):  
Javier Enrique Arévalo Peña
Keyword(s):  
Reference Signal ◽  
Long Term Evolution ◽  
Signal To Noise ◽  
3Gpp Lte ◽  
Term Evolution ◽  
Received Power ◽  
La Red

El presente artículo tiene como propósito realizar la descripción de los resultados de simulación de radiopropagación con una antena MU{MIMO (4x4) en una red LTE (del inglés Long Term Evolution), con el fin de establecer su eciencia respecto a una antena estándar. En esta vía, se emplea la herramienta de diseño de redes inalámbricas ICS Designer en la cartografía digital de alta resolución en un escenario urbano de la ciudad de Bogotá D.C., Colombia. Se utiliza el modelo 3GPP LTE en la simulación de la red LTE y se analizan los parametros RSRP (del inglés, Reference Signal Received Power), RSRQ (del inglés, Reference Signal Recieved Quality), SNIR (del inglés, Signal to Noise and Interference Ratio) rendimiento (Throughput) y QCI (del inglés, QoS Class Identier). Se evidencian, como consecuencia de los resultados, ventajas de las antenas MU-MIMO.

An Improved Physical Downlink Control Channel De-Resource Mapping Method in Long Term Evolution Systems

2014 ◽  
Vol 513-517 ◽  
pp. 3577-3580
Author(s):  
Dan Wang ◽  
Wen Wen Xu ◽  
Jia Luo
Keyword(s):  
Reference Signal ◽  
Long Term Evolution ◽  
Mapping Method ◽  
Control Channel ◽  
Evolution System ◽  
Resource Mapping ◽  
Modified Method ◽  
Term Evolution ◽  
System Resource

In TD-LTE (Time Division-Long Term Evolution) system, Resource Element Group (REG) is the unit of de-resource mapping for Physical Downlink Control Channel (PDCCH), due to the reference signal should be considered, which lead to the large calculation. To solve this problem, a modified method is proposed in this paper to reduce the cycles of de-resource mapping. Calculation and simulation reveal that this scheme can reduce the calculation significantly. At the same time, the feasibility and effectiveness of this modified method have been verified.

scholarly journals ANALISIS ALGORITMA HANDOVER UNTUK MENINGKATKAN KEMAMPUAN ADAPTASI MOBILITAS DI LTE PADA KERANGKA SON (SELF OPTIMIZING NETWORK)

2016 ◽  
Vol 1 (1) ◽  
Author(s):  
Fadilah Rahman ◽  
Nachwan Mufti A. ◽  
Tody Ariefianto W.
Keyword(s):  
Long Term Evolution ◽  
Radio Link ◽  
Parameter Control ◽  
Link Failure ◽  
Threshold Parameter ◽  
Network Mobility ◽  
Term Evolution ◽  
Ping Pong ◽  
Robustness Optimization

Long Term Evolution (LTE) adalah suatu teknologi 4G yang memiliki tingkat mobilitas handover yang tinggi sampai kecepatan 350 km/jam. Namun, aktualnya ada beberapa permasalahan handover, yaitu Radio Link Failure (RLF) dan efek ping-pong. Kedua permasalahan ini terjadi karena pengaturan parameter control handover pada eNodeB yang kurang tepat, sehingga mengakibatkan kegagalan handover dan pingpong handover. Pada LTE Release 9, 3GPP memperkenalkan konsep Self Optimizing Network (SON) melalui metode Mobility Robustness Optimization (MRO). Pada penelitian ini dilakukan proses analisis terhadap algoritma handover inter-eNodeB melalui interface X2 untuk sistem LTE. Sistem tersebut menggunakan metode optimisasi MRO sehingga dapat mengetahui jumlah dan probabilitas kegagalan handover dan pingpong handover dari yang diujikan pada kecepatan tertentu di daerah dense urban, urban, dan rural. Penelitian ini menghasilkan nilai referensi threshold untuk diimplementasikan pada setiap jenis daerah. Pada daerah dense urban, nilai threshold referensi parameter handover yaitu HOM = 5 dB dan TTT = 640 ms. Untuk daerah urban, nilai threshold parameter handover yang ditawarkan yaitu HOM = 4 dB dan TTT = 640 ms. Sedangkan, daerah rural memiliki nilai HOM = 3 dB dan TTT = 256 ms.Kata Kunci: Long Term Evolution, handover, Radio Link Failure, Self Optimizing Network, Mobility Robustness Optimization

Modified Iterative Sphere Decoding Algorithm in LTE System

2013 ◽  
Vol 765-767 ◽  
pp. 611-614
Author(s):  
Qin Zhu ◽  
Xiao Wen Li
Keyword(s):  
Channel Equalization ◽  
Detection Algorithm ◽  
Qr Decomposition ◽  
Sphere Decoding ◽  
Decoding Algorithm ◽  
Algorithm Performance ◽  
Awgn Channel ◽  
Term Evolution ◽  
Simulation Results

In the long-term evolution (LTE) system, channel equalization makes compensation to restore the original signal, the paper puts forward iteration sphere decoding algorithm which combines traditional sphere decoding and the improved QR based on the conventional QR decomposition detection algorithm. It can effectively reduce the system complexity. At the same time, in QPSK and 16QAM, the simulation results show that the improved QR iterative sphere decoding algorithm performance is better with higher SNR in AWGN channel.

scholarly journals Improving the eNodeB Coverage of a Bad Spot Area by Using A Relay Node

2018 ◽  
Vol 2 (02) ◽  
pp. 83
Author(s):  
Fivie Ni'mah ◽  
Hasanah Putri Putri
Keyword(s):  
Field Measurement ◽  
Reference Signal ◽  
Relay Node ◽  
Decode And Forward ◽  
Spot Area ◽  
Term Evolution ◽  
Standard Values ◽  
Long Term Evolution Network

The quality of LTE (Long Term Evolution) network in WR Supratman Street, Bandung is categorized as quite bad as shown by the average RSRP (Reference Signal Receive) and SINR (Signal to Interference Noise Ratio) values of -101.30 dBm and 2.43 dB, respectively. Both parameters are below the standard operator with the average RSRP and SINR standard values of -101.30 dBm and 2.43 dB, respectively. The previous field measurement indicated that the area belonged to a bad spot area caused by shadowing buildings. This study used the node scheme of decode and forward and physical mode of inband relay node with the aim of extending the eNodeB coverage. By applying this technique, the average RSRP value increased by 18% and the average SINR value increased by 53%. Based on the RF (Radio Frequency) parameters, the average RSRP value with samples below the -85 dBm standard improved by 81%, while the average SINR value with samples below 5 dB improved by 45%.

Research on Uplink Channel Estimation Method in TD-LTE System

2011 ◽  
Vol 135-136 ◽  
pp. 847-851
Author(s):  
Cui Zhen Sun ◽  
Zhao Hua Zeng
Keyword(s):  
Channel Estimation ◽  
Estimation Method ◽  
Data Rate ◽  
Pilot Signal ◽  
High Data ◽  
System A ◽  
Term Evolution ◽  
Simulation Results ◽  
Evolution Scheme

LTE is a long term evolution scheme of 3GPP, as a using extensively communication standards, it has higher data rate and higher quality. Channel estimation plays a quite important role in the LTE system which requires the high data rate and quality. In the article, based on the analysis of the LS and MMSE algorithms of the LTE system, a advised algorithm is adopted. The pilot signal is processed before the channel estimation by reducing noise in time domain. The simulation results demonstrate that the advised algorithm is a preferable choice in estimation performance, simultaneously; the advised has obviously reduced the algorithm complexity.

scholarly journals Fuzzy Logic Based Coverage and Cost Effective Placement of Serving Nodes for 4G and Beyond Cellular Networks

2017 ◽  
Vol 2017 ◽  
pp. 1-25 ◽  
Author(s):  
Arthi Murugadass ◽  
Arulmozhivarman Pachiyappan
Keyword(s):  
Site Selection ◽  
Unit Area ◽  
Cost Effective ◽  
Base Stations ◽  
Term Evolution ◽  
Transmission Quality ◽  
Simulation Results ◽  
Coverage Holes

The densification of serving nodes is one of the potential solutions to maximize the spectral efficiency per unit area. This is preposterous on account of conventional base stations (BS) for which site procurement is costly. Long term evolution-advanced (LTE-A) defines the idea of heterogeneous networks (HetNets), where BSs with different coverage and capacity are utilized to guarantee the quality of service (QoS) requirements of the clients. To maximize the transmission quality of the clients in the coverage holes, LTE-A also defines multihop relay (MHR) networks, where the relay stations (RSs) are also placed along with the BSs. Unfortunately, the placement approaches for HetNet and MHR serving nodes are not standardized. In this work, two different approaches like site selection with maximum service coverage (SSMSC) and site selection with minimum placement cost (SSMPC) are proposed, which identifies the required number of serving nodes, their types, and the placement locations to maximize the coverage and to maintain the placement cost (PC) within the limits of the total placement budget. The simulation results demonstrate that the proposed approaches are computationally less complex and offer enhanced performance in terms of aggregate PC, coverage, and power proportion compared to the other conventional approaches.

scholarly journals A Countermeasure against Smart Jamming Attacks on LTE Synchronization Signals

2020 ◽  
pp. 626-632
Author(s):  
Mert Eygi ◽  
◽  
Gunes Karabulut Kurt
Keyword(s):  
Wireless Communication ◽  
Communication Technology ◽  
Energy Efficient ◽  
Specific Region ◽  
Jamming Attacks ◽  
Jamming Attack ◽  
Term Evolution ◽  
Physical Channel ◽  
Simulation Results

Long-Term Evolution (LTE) is one of the most frequently used wireless communication technology. As every wireless network, LTE is vulnerable to physical layer (PHY) jamming attacks due to the broadcast nature of channels. Since the jammer attacks are getting smarter and energy efficient, they can target a specific region or physical channel instead of entire band. Targeting the physical LTE downlink Synchronization Signals (SS) could be the most dangerous objective. In this paper, we investigate LTE PHY jamming attack against only primary and secondary synchronization signals. Jammer detection is performed by using Neyman-Pearson theorem. Then, a countermeasure method is proposed. Simulation results show that the proposed countermeasure can achieve lower pollution and better correct cell id performances during smart jamming attack against SS.

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