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It is well-know that carrier frequency offset in the subcarriers of orthogonal frequency division multiplexing (OFDM) leads to intercarrier interference (ICI); therefore, system degradation occurs. Nevertheless, this issue may effectively be mitigated via the pulse shaping filter method. In this manuscript, we present the improved double jump linear combination (IDJLC) function. With the goal of minimizing...
In this paper, we propose PreDA-a preferencebased truthful double auction for dynamic spectrum access (DSA) networks where multiple heterogeneous spectrum bands are sold by the primary users and bought by the secondary users. We consider channels' heterogeneity and multi-bids from buyers, and also consider buyers' preferences for the channels. We use the signal to interference and noise ratio (SINR)...
This paper considers a frequency-division-duplexing (FDD) massive multiple-input multiple-output (MIMO) system that operates with two-stage beamforming based on user grouping. In this system, we propose a first stage beamformer and a user grouping method for the two-stage beamforming. The proposed first stage beamformer maximizes an approximate sum rate calculated from the second-order statistic of...
The explosive growth of wireless devices requires more aggressive and balanced spectrum sharing and the listen-before-talk (LBT) is still a superior candidate protocol for a high device density. The Modified hardcore point process (HCPP) type II model provides mathematically tractable performances for such LBT networks, but it underestimates the LBT performances. In this regard, this paper evaluates...
In next generation cellular networks, small cell base stations (BSs) with ultra-dense deployments are likely to cooperate together to manage interference and provide users with high data rates. But users may still experience large drops in throughput due to lack of available resources even with high received signal strength. In this paper, we propose a congestion-aware user-centric cooperative BS...
This paper considers an orthogonal frequency division multiplexing system where the Effective Exponential SNR Mapping (EESM) is applied. We first present an approximate model in which the subcarriers grouped into one block are assumed to have the same channel coefficient and, subcarriers in different blocks have independent and identically distributed channel coefficients. Then, we present an algorithm...
Coordinated multipoint transmission (CoMP) and soft frequency reuse (SFR) are two popular techniques used to control the deleterious effects caused by inter-cell interference in current 4G and envisaged 5G cellular networks. The performance of the combination of CoMP and SFR has been shown to be strongly influenced by the specific choice of the parameters governing the action of both mechanisms. Unfortunately,...
MU-MIMO proposed in 802.11ac is to achieve higher data rate, with transmitting to multiple users concurrently. However, the overhead cost by collecting channel state information (CSI) sometimes even overwhelm real data transmission when quantity of user is large, which leads the network and unscalable. In this work, we address the problem with adaptive location-based CSI feedback compression (LFC),...
The Internet of Things (IoT) is a fast-growing movement turning devices into always-connected smart devices through the use of communication technologies. This facilitates the creation of smart strategies allowing monitoring and optimization as well as many other new use cases for various sectors. Low Power Wide Area Networks (LPWANs) have enormous potential as they are suited for various IoT applications...
Adaptive beamformers aim for improved resolution and contrast in the ultrasound images, and their performance is typically benchmarked using metrics such as contrast ratio (CR) and contrast-to-noise ratio (CNR). Using synthetic aperture Field II simulations, we show that certain beamformers alter speckle statistics and that this opens up for cherry picking of contrast metrics.
In this paper, the BER performance of a soft distance successive cancellation decoder for Polar codes is analyzed in the presence of impulsive noise, modelled using both the Middleton's Class A model and the symmetric alpha-stable model, for impulsive noise channels. This algorithm avoids estimation of the signal-to-noise ratio of the channel, and simplifies the initialization step of the classic...
Although the base station processing and the majority of the protocols of the wireless systems are standardized by 3GPP, the receiver architecture and implementation remain vendor-dependent. The receiver design should fulfill computational efficiency requirements, and be evaluated in practical simulators or emulators that are compliant with real-world wireless standards. In this paper, we provide...
In addition to high data rate, millimeter-wave technology has great potential to provide extremely high localization accuracy. In this paper, we outline the benefits of this technology for positioning and their main applications, which are no longer confined to services only but also to improve communication. We shall focus on the trade-off between data communication and positioning looking the reconfiguration...
In cellular networks, end-users receive wireless network services only by a base station (BS). Device-to-device (D2D) communication is a new paradigm in cellular network that enables end-users to communicate with each other in an ad hoc manner using single or multi-hops. The communication can be realized both with and without the support of the cellular network infrastructure. A major challenge associated...
Many wireless networks provide a large number of available channels for data transmissions. Due to the multi-path environment, channels have different channel qualities. There- fore, selecting a good channel from the multiple channels can improve the communication effectiveness. The Packet Reception Rate (PRR) has been utilized to represent the channel quality. In order to know which channel has good...
This paper proposes a modified IMWBF decoding algorithm for low-density parity-check (LDPC) codes. In the proposed modification, the magnitude of the received signal is updated when the number of the unsatisfied parity-check equations participated by this received signal is larger than a predetermined threshold. Through this modification, the outlier, defined as the undesired large-magnitude received...
Caching at the edge is a promising technique to cope with the increasing data demand in wireless networks. This paper analyzes the performance of cellular networks consisting of a tier macro-cell wireless backhaul nodes overlaid with a tier of cache-aided small cells. We consider both static and dynamic association policies for content delivery to the user terminals and analyze their performance....
In this paper, a code-aided maximum-likelihood and moment-based joint SNR estimator is proposed for M- ary amplitude phase shift keying (APSK) signals over AWGN channels. The proposed estimator significantly improves the performance at low SNRs by utilizing the syndrome in the LDPC codes to act as a reference measurement of estimation performance. Moreover, a methodology to measure the performance...
Machine-type communications (MTC), considered as one of potential technologies in 5G, has attracted more and more attention in recent years. Massive MTC connection density but with small data rate leads to preamble deficiency and network congestion in the network. In order to solve this problem, we jointly utilize the back off strategy and the hierarchical access control method. We formulate a Quality...
In a Fog Radio Access Network (F-RAN) architecture, edge nodes (ENs), such as base stations, are equipped with limited-capacity caches, as well as with fronthaul links that can support given transmission rates from a cloud processor. Existing information-theoretic analyses of content delivery in F-RANs have focused on offline caching with separate content placement and delivery phases. In contrast,...
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