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Fully automated vehicles are currently under research and development and will become reality in the near future. Key enabling sensors in this area are automotive radars, which currently support driving comfort and crash prevention. These radars operate in the 24 GHz and 76–81 GHz bands as of today and occupy the spectrum heavily. Hence automotive radar sensors require immunity to interference of...
In distributed storage, erasure codes are widely used to provide data reliability, where every codeword symbol corresponds to one storage node. The network traffic cost during the repair of node failures, called repair bandwidth, is an important metric in code design. In particular, minimum storage regenerating (MSR) codes are maximum distance separable (MDS) codes that have optimal repair bandwidth...
In this study, a sawtooth-shape scalable frequency selective surface structure (FSS) for X-band applications is presented. The proposed FSS structure intended to be used in shielding of X-band satellite communication systems to reduce the interference effect is specifically tuned to be operated in 10–12 GHz band and it is aimed to have a stable response at oblique incidence. The scalable design allows...
In this work, we introduce a powerful hardware-based rogue access point (PrAP), which can relay traffic between a legitimate AP and a wireless station back and forth, and act as a man-in-the-middle attacker. Our PrAP is built of two dedicated wireless routers interconnected physically, and can relay traffic rapidly between a station and a legitimate AP. Through extensive experiments, we demonstrate...
Dynamic time-division duplexing (TDD) is considered a promising solution to deal with fast-varying traffic often found in ultra-densely deployed networks. At the same time, it generates more interference which may degrade the performance of some user equipment (UE). When base station (BS) utilization is low, some BSs may not have an UE to serve. Rather than going into sleep mode, the idle BSs can...
Spectrally precoded OFDM is a recent approach that aims for the suppression of the OOB, as well as the in-band gap, emissions in OFDM systems. Theoretically, the technique shows High suppression of the OOB and the in-band gap emissions. Although, practically hardware impairments may limit the precoder's performance. Yet, this demonstration shows that despite the hardware impairments, implemented spectrally...
Licensed-Assisted Access (LAA) is a new operation mode for the Long Term Evolution Advanced systems to transmit data via both licensed spectrum and unlicensed spectrum based on the framework of carrier aggregation. For LAA uplink (UL) transmission, there is a mismatch between resource allocation and actual data transmission due to the requirement of listen-before-talk (LBT). Such a mismatch may cause...
In this paper, we investigate the problem of pilot optimization, resource allocation, and user association in a massive MIMO heterogeneous network (HetNet) with wireless backhaul (WB) and linear processing. The objective is to maximize the sum downlink rate of all users, subject to constraints on data rate of WB and fairness-aware constraints. Such a problem is formulated as an integer programming...
In this paper we consider a centralized radio access network (C-RAN) architecture with a fully analog fronthaul link between remote antenna units (RAUs) and baseband units (BBUs) based on the radio over fiber (RoF) paradigm. Beamforming to separate uplink signals received from a pool of users is splitted between RAU and BBU. Optical beamforming is performed at the RAU site with the aim of reducing...
Nonlinear power amplifiers distort the transmitted signal and out-of-band (OOB) radiation becomes a source of interference for users operating in adjacent channels. This paper studies the effect of Massive Multiple Input Multiple Output (MIMO) system on the OOB interference. Massive MIMO relies on channel based precoding which ensures the signal is added constructively at the receiver user equipment...
Fifth generation (5G) wireless networks will target at energy and spectrum efficient solutions to cope with the increasing demands in capacity and energy efficiency. To achieve this joint goal, dense networks of small cells (SCs) are expected to overlay the existing macro cells. In parallel, for the SC connection to the core network, a promising solution lies in a mesh network of high capacity millimeter...
Wi-Fi is the dominant wireless indoor broadband solution and thus key for meeting the exponential traffic growth. The recent IEEE 802.11ac amendment enables PHY data rates exceeding 1 Gbps. However, it is not clear how this increased per-link performance, achieved especially via wider channels, translates to network-level performance. The latter is crucial for understanding the true potential of emerging...
In this paper, we use a Spectrum Sharing/allocation algorithm to implement a Cognitive Radio network without spectral awareness. This allows radio resources to be allocated to primary users and to secondary users in such a way that primary system and secondary system are aware of each other. By doing this, sensing of spectrum holes is avoided but the primary users will be protected and will always...
Centralized Radio Access Network (C-RAN) architecture is the enabling technology for the deployment of massive number of antennas essential to meet the requirements of next generation (5G and beyond) mobile systems. In C-RAN the fronthaul links between processing Base Band Units (BBUs) and Remote Antenna Units (RAUs) are conventionally based on fiber optic, although its deployment cost can be excessive...
This paper considers a multicarrier faster-than-Nyquist (FTN) transceiver architecture when spectrally efficient frequency division multiplexing (SEFDM) is also utilized at the transmitter. The received symbols are corrupted by both the introduced inter-symbol interference (ISI) due to FTN and inter-carrier interference (ICI) due to SEFDM. The interferences have to be eliminated to recover the transmitted...
Recent development of wireless communications has resulted to the augmentation of small cell to traditional macrocell networks. This constitutes an improved coverage and system capacity of the networks. However, it consequently results to interference and high blockage rate, which are the problems we are treating in this paper. This work proposes two cell selection schemes that adopt the enhanced...
In datacenter networks, flows can have different performance objectives. We use a tenant-objective division to denote all flows of a tenant that share the same objective. Bandwidth allocation in datacenters should support not only performance isolation among divisions but also objective-oriented scheduling among flows within the same division. This paper studies the Multi-Tenant Multi-Objective (MT-MO)...
In this paper, the spectrum sharing in both licensed and unlicensed bands under heterogeneous networks (HetNets) is investigated. A frame architecture of licensed-assisted access (LAA) in unlicensed bands is introduced by analyzing its statistical behavior of channel access opportunity. A multi-objective optimization problem is then designed for small cell to enhance energy efficiency by jointly maximizing...
In this work, it is studied the performance of a scheduling algorithm where the Mobile Terminals (MTs) may be turned off if they cause a level of interference greater than a given threshold. This approach, which is referred to as Interference Aware Muting (IAM), may be regarded as an interference-aware scheme that is aimed to reduce the level of interference. The performance of IAM is studied in terms...
Centralized Radio Access Network (C-RAN) architecture is considered the only viable solution to handle the complex interference scenarios generated by massive antenna and small cell deployment foreseen for next generation (5G) mobile networks. The fronthaul links used to exchange the signal between Base Band Units (BBUs) and Remote Radio Heads (RRHs) are conventionally based on optical fiber, due...
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