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The incremental needs of the wireless technologies came from the rapid proliferation of the mobile devices, which become one of the life necessities for people. The clear growth in the mobile application markets either in video, audio, or web surfing and with all the innovations and inventions in the technologies, the needs of using the wireless heterogenous networks become a fact. In this paper,...
LTE networks are deployed to increase capacity and coverage especially for the indoor and cell-edge mobile users. However, such deployment comes with major challenges, radio resource management and inter-cell interferences. Fractional Frequency Reuse mechanism (FFR) is one of the most effective interference avoidance techniques. In this paper, we evaluate an existing adaptation process that adjusts...
Carrier aggregation supports an increased total bandwidth, data rate and utilization of available fragmented spectrum, where the latter is a core component of next generation Wi-Fi and Cellular networks, including 5G. Wireless communications receivers with intra-band non-contiguous CA, employing conventional complex mixers and base-band circuitry, are desirable, however risks of VCO injection pulling...
With the categories of mobile communication services increasing, the positioning technology based on the base station (BS) in long term evolution (LTE) attracts more and more attention. When it comes to realize the indoor positioning of mobile phone, it is relatively difficult due to multipath, pedestrian interference, power attenuation and so on. In this paper, we use the sounding reference signal...
This paper presents a technique in detection and compensation of spurious signals, and a cancellation system for processing baseband signals. The proposed canceler detects standing spurious signals present in a sampled bandwidth through the digitization and processing of the incoming waveform. These spurs can come from sources such as internally generated spur from signal coupling, or external interference...
Time reversal (TR) have been widely used in underwater acoustic signal recovery. When compared with active TR, passive TR can achieve spatial-temporal compression with one-way propagation, which is more convenient to apply and can reduce the system requirement. Chirp signal, which has unique pulse compression, can effectively be combined with conventional phase, frequency, amplitude modulation with...
Chirp spread spectrum (CSS) technique is capable of providing high processing gain, low power, robustness to multipath interference and immunity to Doppler frequency offset. The paper presents a new phase-coded modulation technique for CSS multiuser communication. The construction of a nth power chirp signal is explained and the design of the phase-coded linear chirp signal is presented in detail...
In this paper we consider the problem of channel allocation for users who access a common channel using OFDMA. The spectrum is divided into subchannels and we assume that the bandwidth of each subchannel is smaller than the coherence bandwidth. This leads to correlations between the channel coefficients for each user. We model these correlated channels as an m-dependent sequence and generate an interference...
In the present paper we evaluate the performance of a hybrid digital/analog multi-beam beam-forming architecture with polarization and delay compensation using time reversal (TR). Double-directional, ultra wideband dual-polarized channel measurements at 70 GHz in a conference room have been used to emulate the channel. The use of multiple beams to mitigate human shadowing has been evaluated and the...
The Citizens Broadband Radio Service (CBRS) band has three tiers of users. The General Authorized Access (GAA) has the lowest priority and operates without a license. A Spectrum Access System (SAS) is responsible for managing spectrum among the users. The Federal Communications Commission (FCC) rules specify that GAA users be allocated resources in a fair manner, but the method to do so is left open...
We propose an architecture that incorporates a robust and agile primary user (PU) detection, accompanied by a dynamic OFDM spectrum allocation scheme. By exploiting the capabilities of a 2×2 MIMO PCIe SDR device we are able to maximize the usage of the available spectrum with the minimal PU disturbance.
Virtual Sensor Networks (VSNs) envision the creation of general purpose wireless sensor networks which can be easily adapted and configured to support multifold applications with heterogeneous requirements, in contrast with the classical approach of wireless sensor networks vertically optimized on one specific task/service. The very heart of VSNs' vision is the capability to dynamically allocate shared...
MICROWAVE beamforming (MBF) is advantageous over digital beamforming (DBF) in several regards [1]. First, due to a lower number of RF down-converters and analog to digital converters (ADC), MBF structures have lower size, weight and battery power consumption. Second, due to weighting and combining of signals in the analog domain and avoiding quantization errors, MBFs have higher dynamic and suppression...
Wi-Fi Mesh Community has turn out to be an important area community to offer internet to challenge the thrown domains and wireless link in metropolitan environments. In this paper, hassle of figuring out the most to be had bandwidth direction is targeted, which is an essential problem in helping pleasant-of-carrier in WMCs. Due to the concept of interference, bandwidth, which is a familiar challenging...
Task colocation improves datacenter utilization but introduces resource contention for shared hardware. In this setting, a particular challenge is balancing performance and fairness. We present Cooper, a game-theoretic framework for task colocation that provides fairness while preserving performance. Cooper predicts users' colocation preferences and finds stable matches between them. Its colocations...
Ultra-wideband RF systems offer a multitude of advantages over narrow band systems. One major point is that these systems can perform multiple functions, like communications, radar and others all using the same aperture. This big advantage of these systems is at the same time their biggest handicap: The wideband receivers are open to much more types of signals compared to narrow band systems. Due...
Non-orthogonal multiple access (NOMA) is considered as a promising candidate for fifth generation (5G) wireless networks. Although, NOMA promises large data rates, however, it also offers significant interference especially when the number of users is large. Therefore, in this paper, we propose a low complexity orthogonal frequency division multiple access (OFDMA)-based NOMA system, which uses the...
In this paper, we propose an auction based spectrum allocation scheme considering a primary user (PU), who is willing to sell the unused spectrum bands to multiple secondary users (SUs). Each SU is allowed to place multiple bids-each bid is a tuple consisting of amount of bandwidth requested and the corresponding price the SU is willing to pay for that bandwidth. The bids from a SU follow a typical...
This paper proposes a simple coordinated multipoint (CoMP) transmission method for taxi radio systems in order to prevent inter-cell interference (ICI) without a significant renewal of facilities. The proposed method takes advantage of the interesting property that the ICI which is essential for CoMP can be represented by the communication distance easily obtained from vehicle position information...
Device-to-device transmission technology can help base stations achieve high transmission rates and meet high-capacity requirements. It is also a key technology for future markets. Additionally, the coexistence of licensed and unlicensed bands will be relevant to the landscape of the emerging 5th-generation cellular systems. However, there is a shortage of research on efficient transmission during...
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