460 research outputs found
A Utility Proportional Fairness Resource Allocation in Spectrally Radar-Coexistent Cellular Networks
Spectrum sharing is an elegant solution to addressing the scarcity of the
bandwidth for wireless communications systems. This research studies the
feasibility of sharing the spectrum between sectorized cellular systems and
stationary radars interfering with certain sectors of the communications
infrastructure. It also explores allocating optimal resources to mobile devices
in order to provide with the quality of service for all running applications
whilst growing the communications network spectrally coexistent with the radar
systems. The rate allocation problem is formulated as two convex optimizations,
where the radar-interfering sector assignments are extracted from the portion
of the spectrum non-overlapping with the radar operating frequency. Such a
double-stage resource allocation procedure inherits the fairness into the rate
allocation scheme by first assigning the spectrally radar-overlapping
resources
An Application-Aware Spectrum Sharing Approach for Commercial Use of 3.5 GHz Spectrum
In this paper, we introduce an application-aware spectrum sharing approach
for sharing the Federal under-utilized 3.5 GHz spectrum with commercial users.
In our model, users are running elastic or inelastic traffic and each
application running on the user equipment (UE) is assigned a utility function
based on its type. Furthermore, each of the small cells users has a minimum
required target utility for its application. In order for users located under
the coverage area of the small cells' eNodeBs, with the 3.5 GHz band resources,
to meet their minimum required quality of experience (QoE), the network
operator makes a decision regarding the need for sharing the macro cell's
resources to obtain additional resources. Our objective is to provide each user
with a rate that satisfies its application's minimum required utility through
spectrum sharing approach and improve the overall QoE in the network. We
present an application-aware spectrum sharing algorithm that is based on
resource allocation with carrier aggregation to allocate macro cell permanent
resources and small cells' leased resources to UEs and allocate each user's
application an aggregated rate that can at minimum achieves the application's
minimum required utility. Finally, we present simulation results for the
performance of the proposed algorithm.Comment: Submitted to IEE
A Price Selective Centralized Algorithm for Resource Allocation with Carrier Aggregation in LTE Cellular Networks
In this paper, we consider a resource allocation with carrier aggregation
optimization problem in long term evolution (LTE) cellular networks. In our
proposed model, users are running elastic or inelastic traffic. Each user
equipment (UE) is assigned an application utility function based on the type of
its application. Our objective is to allocate multiple carriers resources
optimally among users in their coverage area while giving the user the ability
to select one of the carriers to be its primary carrier and the others to be
its secondary carriers. The UE's decision is based on the carrier price per
unit bandwidth. We present a price selective centralized resource allocation
with carrier aggregation algorithm to allocate multiple carriers resources
optimally among users while providing a minimum price for the allocated
resources. In addition, we analyze the convergence of the algorithm with
different carriers rates. Finally, we present simulation results for the
performance of the proposed algorithm.Comment: Submitted to IEE
Coexistence Analysis between Radar and Cellular System in LoS Channel
Sharing spectrum with incumbents such as radar systems is an attractive
solution for cellular operators in order to meet the ever growing bandwidth
requirements and ease the spectrum crunch problem. In order to realize
efficient spectrum sharing, interference mitigation techniques are required. In
this letter we address techniques to mitigate MIMO radar interference at MIMO
cellular base stations (BSs). We specifically look at the amount of power
received at BSs when radar uses null space projection (NSP)-based interference
mitigation method. NSP reduces the amount of projected power at targets that
are in-close vicinity to BSs. We study this issue and show that this can be
avoided if radar employs a larger transmit array. In addition, we compute the
coherence time of channel between radar and BSs and show that the coherence
time of channel is much larger than the pulse repetition interval of radars.
Therefore, NSP-based interference mitigation techniques which depends on
accurate channel state information (CSI) can be effective as the problem of CSI
being outdated does not occur for most practical scenarios.Comment: Corrected some typos and reference
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