LTE physical layer Research Papers (original) (raw)

A 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) system uses the concept of two-tier heterogeneous networks (HetNets), where low-power and short-range femtocells are laid under macrocells to fulfill the quality of... more

A 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) system uses the concept of two-tier heterogeneous networks (HetNets), where low-power and short-range femtocells are laid under macrocells to fulfill the quality of service (QoS) requirements of users and to boost overall network capacity. However, co-channel interference is one of the major issues that need to be resolved for the successful deployment of HetNets. To overcome this problem, fractional frequency reuse (FFR) schemes have been proposed that can efficiently utilize the available spectrum. Nevertheless, these schemes waste limited frequency resources owing to their static allocation and lack of following QoS requirements, network loading conditions, and service priority of users. In this paper, a QoS-based dynamic FFR (QoS-DFFR) scheme is proposed that efficiently allocates the non-occupied center-zone frequency bands, i.e., bonus bandwidth (BBW), to cell-edge users by considering their QoS requirements...

Power and Coverage Based Performance Analysis for Femtocells Network Muhammad Jamshed Abbas, Muhammad Awais**, Waqas Ahmad Mirza, Jibran Hashim, Sohail Abbas, Arsalan Hameed Department of Electrical Engineering, Riphah International... more

Power and Coverage Based Performance Analysis for Femtocells Network Muhammad Jamshed Abbas, Muhammad Awais**, Waqas Ahmad Mirza, Jibran Hashim, Sohail Abbas, Arsalan Hameed Department of Electrical Engineering, Riphah International University Islamabad, Pakistan Transmission and Distribution Systems Research Institute, North China Electric Power University Beijing, China Emails: jamshed.abbas@outlook.com, m.awais.warraich@outlook.com, waqasmirza@hotmail.com, ABSTRACT The study of mobile communication/ cellular network in the industry of telecommunication is the fast-growing technology of this era. Demands of higher data rates in the indoor environment is increasing day by day. To achieve this demand femtocells are the best option for indoor environment. In the coming future, Femtocell is most important and best case for low power and low-cost base stations for indoor users. It is widely acceptable that by providing better quality in indoor environment, there will be a great revenue...

Zero padded single carrier spatial modulation system is an effective method of data transmission. This system achieves full multipath diversity and imposes a relatively low maximum likelihood detection complexity. However the main... more

Zero padded single carrier spatial modulation system is an effective method of data transmission. This system achieves full multipath diversity and imposes a relatively low maximum likelihood detection complexity. However the main drawback of this system is that it suffers from high Peak-to-Average problem. In this paper, we propose an effective reduction scheme that combines Discrete Cosine transform and Selective mapping technique along with zero padding. The scheme is composed of the Discrete Cosine transform followed by the Selective mapping using the Riemann matrix to obtain phase sequences for the Selective mapping technique. The simulation results shows that the PAPR can be greatly reduced by applying the proposed system with low complexities computation and the bit error rate performance is significantly better than the zero padded spatial modulation technique. This approach also avoids randomness in phase sequence selection to provide easier decoding at the receiver. Also t...

In present paper, the analysis on the reliable performance of the acoustic wave based underwater wireless sensor network communication is done. Underwater wireless sensor network deployment is increasing day by day because of immense use... more

In present paper, the analysis on the reliable performance of the acoustic wave based underwater wireless sensor network communication is done. Underwater wireless sensor network deployment is increasing day by day because of immense use in different applications such as earthquake and tsunami pre-warning, climate and ocean natural resources investigations, and water pollution monitoring etc. In this paper, A discussion will be done on system propagation channel modelling of acoustic communication network in underwater and its corresponding challenges. In ocean bottom and surface of oceans, the sensor nodes, surface stations, and global positioning system form underwater acoustic sensor network that serve as gateways and provide radio communication links to on-shore base stations. This force to characterize a path loss in underwater acoustic channel that can be calculated on basis of signal frequency travelling in oceans and transmission distance, absorption loss and attenuation, Si...

this paper explores the recent applications of wireless sensor networks (WSNs), especially Underwater WSNs (UWSN), by International Oil Companies (IOCs) in monitoring underwater oil pipelines in Nigerian oil rich Niger Delta region. It... more

this paper explores the recent applications of wireless sensor networks (WSNs), especially Underwater WSNs (UWSN), by International Oil Companies (IOCs) in monitoring underwater oil pipelines in Nigerian oil rich Niger Delta region. It examined the different architectures for monitoring underwater pipelines, their challenges and how to overcome them. The paper also looked at how underwater WSNs can be used together with their measurement and communication devices such as GSM modem and Global Positioning System (GPS) to transfer sensed data from underwater network to control station far away from the pipeline.

This paper investigates the concept of Mobile Femtocell with considering the feasibility of deploying Mobile Femtocells in public transportation vehicles such as trains, buses or private cars that form its own cell inside vehicles to... more

This paper investigates the concept of Mobile Femtocell with considering the feasibility of deploying Mobile Femtocells in public transportation vehicles such as trains, buses or private cars that form its own cell inside vehicles to serve vehicular and mobile User Equipments. This study is the launch of cell-edge mobile users who have always suffered degradation in the Quality of Service (QoS). Therefore, an investigation on the performance of LTE cell-edge mobile User Equipment e.g. users’ throughput, SINR, SNR, SIR, spectral efficiency and Handover performance, have been considered with deploying Fixed Femtocells and Mobile Femtocells in Long Term Evolution network. Two scenarios have been proposed in this study; Fixed Femtocells with mobile users and Mobile Femtocells with mobile users. More scenarios maybe considered in the case of Mobile Femtocell’s handover procedure. MATLAB simulation has been used for the purpose of simulating the designed scenarios and implementing the int...

Using simulation tools save the construction cost of the wireless system. It is not necessary to establish the system and test whether it is working properly or not. Therefore, simulation tools are required to be accurate, simple and with... more

Using simulation tools save the construction cost of the wireless system. It is not necessary to establish the system and test whether it is working properly or not. Therefore, simulation tools are required to be accurate, simple and with the minimum time. From the accuracy perspective, the stacked femtocells built in most available simulators in the literature are widely deployed horizontally. However, this is not the case in the indoor environment where femtocells have to be arranged vertically; such as, in residential towers where apartments are on the top of each other. In this paper, the state of the art of link and system level simulators is introduced. In addition, a three-dimensional (3D) system level simulator is developed in order to help the researcher in the Long Term Evolution (LTE) femtocell field to analyze and investigate more real scenarios of femtocell deployment. The developed simulator allows the researcher to locate a multi-story building in the region of intere...

The fourth-generation networks based on OFDMA (3GPP LTE) (3rd Generation Partnership Project Long Term Evolution) offer high bit rate and takes into account in their mechanisms the simplicity and efficiency of the radio transmission. But... more

The fourth-generation networks based on OFDMA (3GPP LTE) (3rd Generation Partnership Project Long Term Evolution) offer high bit rate and takes into account in their mechanisms the simplicity and efficiency of the radio transmission. But with the volume of traffic constantly increasing, especially in high density population environments, the reuse of bandwidth is the only effective way to increase the capacity in LTE system. The conventional approach to improve the spectrum efficiency is to reuse the same frequency band in multiple geographic areas or cells. However, inter-cell interference (ICI) will inevitably disadvantageous, when the mobile stations or users in adjacent cells share the same spectrum. High mobility makes the situation worse. The SINR at the Cell-edge may be so poor that even the most robust control channel PDCCH cannot function properly. This is one of the major problems limiting the performance of LTE (Long Term Evolution). This work studies the impact of inter-...

The key characteristic of a cellular network is the ability to reuse frequencies to increase both coverage and capacity. Fractional frequency reuse (FFR) is considered to be an efficient inter-cell interference coordination technique... more

The key characteristic of a cellular network is the ability to reuse frequencies to increase both coverage and capacity. Fractional frequency reuse (FFR) is considered to be an efficient inter-cell interference coordination technique well-suited for OFDMA based on wireless communication networks where the cells are partitioned into spatial regions with different frequency reuse factors. In this paper, evaluating strict FFR which represents a type of FFR deployments is presented with four different system models by changing the inner-cell shape for each model. System simulations are used to compare and evaluate the effect of changing the inner-cell shape based on strict FFR performance which performed using dense Monte Carlo simulations. In addition, the effects of some system model parameters are discussed.

The huge capacity requirements for the next generation mobile network is defining the technologies that will drive the future system. The trio of millimeter wave, massive MIMO and small cell are emerging as the tripod upon which the... more

The huge capacity requirements for the next generation mobile network is defining the technologies that will drive the future system. The trio of millimeter wave, massive MIMO and small cell are emerging as the tripod upon which the upcoming network is expected to thrive. With about 80% indoor mobile usage, small cell and by extension, femtocell is projected to deliver the bulk of the predicted mobile traffic. This paper takes an overview of the future 5G network and advances solutions to the most anticipated interference challenges as a result of cell densification.

To reduce the occurrence of high peak-to-average power ratio (PAPR), this paper introduces prolate-binary sequences, and their application in orthogonal frequency division multiplexing (OFDM) systems that implement selected mapping (SLM).... more

To reduce the occurrence of high peak-to-average power ratio (PAPR), this paper introduces prolate-binary sequences, and their application in orthogonal frequency division multiplexing (OFDM) systems that implement selected mapping (SLM). Through computer simulation, it is shown that the proposed prolate-binary sequences offer combined improved PAPR reduction performance, and reduced computational complexity compared with Riemann-binary sequences.

This paper studies control format indicator (CFI) estimation methods in 4G-LTE communication systems. CFI is an essential control signal in LTE, and must be correctly detected at the receiver to avoid degraded system performance. The... more

This paper studies control format indicator (CFI) estimation methods in 4G-LTE communication systems. CFI is an essential control signal in LTE, and must be correctly detected at the receiver to avoid degraded system performance. The standard method of CFI detection involves the use of the Maximum Likelihood (ML) estimation criterion. Unfortunately, ML decoding performance relies on accurate channel estimation, and as a consequence may result in poor CFI decoding when channel estimates are poor. To improve CFI detection in severe fading channel conditions, a time-domain decision rule that requires no channel estimation, is proposed. Results show that when compared with the ML approach, the proposed method reduces the probability of CFI estimation error in the form of reduced block error rate.

This paper addresses the issue of high computational complexity associated with side information (SI) estimation in orthogonal frequency division multiplexing (OFDM) systems that implement selected mapping (SLM) to reduce peak-to-average... more

This paper addresses the issue of high computational complexity associated with side information (SI) estimation in orthogonal frequency division multiplexing (OFDM) systems that implement selected mapping (SLM) to reduce peak-to-average power ratio (PAPR). The proposed method is based on a slightly modified SLM approach that enables the use of a low complexity binary detection criterion for SI estimation, without the need for SI transmission. Simulations show that the combined PAPR reduction and BER performance of the proposed method is similar to both pilot-assisted Maximum-Likelihood (PAML) SI estimation scheme and standard SLM that presumes perfect knowledge of SI. In addition, relative to the PAML scheme, the proposed method offers significantly reduced computational complexity.

Side information (SI) detection is normally needed to achieve successful data reception when selected mapping is implemented for reducing peak-to-average power ratio in orthogonal frequency division multiplexing systems. In severe... more

Side information (SI) detection is normally needed to achieve successful data reception when selected mapping is implemented for reducing peak-to-average power ratio in orthogonal frequency division multiplexing systems. In severe frequency selective channel fading, existing pilot-assisted SI estimation schemes are ineffective especially when the number of pilots is limited, resulting in performance degradation in the form of increased BER. To address this problem, an alternative pilot-assisted SI estimation method based on a time-domain decision metric is proposed. Simulations show that when compared to a pilot-assisted SI estimation scheme based on frequency domain correlation, the proposed method provides improved SI estimation performance in the form of reduced SI detection error rate.

Binary sequences such as chaotic-binary (CB) sequences derived from an iterative chaotic equation have been used in selected mapping (SLM) methods to reduce the peak-to-average power ratio (PAPR) in orthogonal frequency division... more

Binary sequences such as chaotic-binary (CB) sequences derived from an iterative chaotic equation have
been used in selected mapping (SLM) methods to reduce the peak-to-average power ratio (PAPR) in orthogonal
frequency division multiplexing (OFDM) systems. Though CB sequences have been shown to produce good PAPR
reduction performance, their implementation requires a significant number of complex computations which may
increase both design costs and energy requirements. This paper presents an alternative form of binary sequences
derived from a Fibonacci series and referred to as Fibonacci-Binary (FB) sequences. Simulations show that although
CB sequences produce slightly improved PAPR reduction performance over the proposed FB sequences
for larger numbers of applied SLM vectors, both forms of binary sequences produce similar bit-error-rate (BER)
performance even in the presence of non-linear power amplifier distortion. In terms of computational complexity
however, it is shown that FB sequences have significantly reduced computational requirements over CB sequences
and thus may be considered as preferred option for reducing PAPR in SLM based OFDM systems.

The growing demand for group-oriented services has recently attracted the interest of the research community. Several proposals have been designed for the most promising broadband wireless system, Long Term Evolution-Advanced (LTE-A), to... more

The growing demand for group-oriented services has recently attracted the interest of the research community. Several proposals have been designed for the most promising broadband wireless system, Long Term Evolution-Advanced (LTE-A), to enhance key performance figures such as spectrum efficiency, data rate and user satisfaction. Starting from the standard proposals for multicasting and broadcasting systems, in this paper we investigate the potentialities of Device to Device (D2D) communications for enhancing the performance of multicast communications. While keeping the objective of serving all users in a multicast group, as for the Conventional Multicast Scheme (CMS), more performing Modulation and Coding Schemes (MCS) are adopted in the path from the base station to users, by leveraging D2D links to serve nodes with worse channel conditions. Radio resources for the activated transmission links from the base station and for the D2D links are managed in order to maximize the aggregate data rate. A simulative performance evaluation in a wide set of scenarios shows the significant achievable improvements.

Nowadays, the growing demand for group-oriented services over mobile devices has lead to the definition of new communication standards and multimedia applications in cellular systems. In this article we study the use of game theoretic... more

Nowadays, the growing demand for group-oriented services over
mobile devices has lead to the definition of new communication standards and multimedia applications in cellular systems. In this article we study the use of game theoretic solutions for these services to model and perform a trade-off analysis between fairness and efficiency in the resources allocation. More precisely, we model bargaining solutions for the multicast data services provisioning and introduce the analytical resolution for the proposed solutions.

Long Term Evolution (LTE) is considered the most promising cellular system able to support the growing demand of multicast services (e.g., IPTV, video streaming) over mobile terminals. The design of effective strategies for the management... more

Long Term Evolution (LTE) is considered the most promising cellular system able to support the growing demand of multicast services (e.g., IPTV, video streaming) over mobile terminals. The design of effective strategies for the management of these applications is still an open issue, especially in scenarios where several multicast streams are simultaneously transmitted in a cell. In this paper we propose different resource allocation policies for the delivery of multicast scalable video flows. Such policies efficiently exploit the multi-user diversity and the frequency selectivity in order to match the requirements of both users and providers. The performance of the proposed strategies is analyzed through simulations by evaluating different cell deployment and user load environments and by focusing on spectral efficiency, throughput, fairness, and amount of resources needed for multicast service delivery. The last parameter is important in practical scenarios where multicast services share the available resources with other flows, e.g., unicast services.

"This paper addresses the design of an adaptive resource allocation policy for the efficient delivery of multicast services in Long Term Evolution (LTE) systems. The proposed approach overcomes the intrinsic inefficiencies of... more

"This paper addresses the design of an adaptive resource allocation policy for the efficient delivery of multicast services in Long Term Evolution (LTE) systems.
The proposed approach overcomes the intrinsic inefficiencies of Conventional Multicast Scheme (CMS) related to the different channel quality experienced by the involved users.
The basic idea is to split any multicast group into subgroups and apply subgroup-based adaptive modulation and coding schemes, which enable a more efficient exploitation of multi-user diversity.
The distribution of users into subgroups is determined by the solution of an optimization problem, aiming to improve the network throughput while guaranteeing fairness among multicast members."