97,054 research outputs found
A Dynamic Clustering and Resource Allocation Algorithm for Downlink CoMP Systems with Multiple Antenna UEs
Coordinated multi-point (CoMP) schemes have been widely studied in the recent
years to tackle the inter-cell interference. In practice, latency and
throughput constraints on the backhaul allow the organization of only small
clusters of base stations (BSs) where joint processing (JP) can be implemented.
In this work we focus on downlink CoMP-JP with multiple antenna user equipments
(UEs) and propose a novel dynamic clustering algorithm. The additional degrees
of freedom at the UE can be used to suppress the residual interference by using
an interference rejection combiner (IRC) and allow a multistream transmission.
In our proposal we first define a set of candidate clusters depending on
long-term channel conditions. Then, in each time block, we develop a resource
allocation scheme by jointly optimizing transmitter and receiver where: a)
within each candidate cluster a weighted sum rate is estimated and then b) a
set of clusters is scheduled in order to maximize the system weighted sum rate.
Numerical results show that much higher rates are achieved when UEs are
equipped with multiple antennas. Moreover, as this performance improvement is
mainly due to the IRC, the gain achieved by the proposed approach with respect
to the non-cooperative scheme decreases by increasing the number of UE
antennas.Comment: 27 pages, 8 figure
Panama City Fisheries Resources Office: FY 2003 Annual Report
HIGHLIGHTS FOR FY 2003
1. Continued a 3-year threatened Gulf sturgeon population estimate in the Escambia
River, Florida and conducted presence-absence surveys in 4 other Florida river
systems and 1 bay.
2. Five juvenile Gulf sturgeon collected, near the mouth of the Choctawhatchee
River, Florida, were equipped with sonic tags and monitored while over-wintering
in Choctawhatchee Bay.
3. Continued to examine Gulf sturgeon marine habitat use.
4. Implemented Gulf Striped Bass Restoration Plan by coordinating the 20th Annual
Morone Workshop, leading the technical committee, transporting broodfish, and coordinating the stocking on the Apalachicola-Chattahoochee-Flint (ACF) river
system.
5. Over 73,000 Phase II Gulf striped bass were marked with sequential coded wire
tags and stocked in the Apalachicola River. Post-stocking evaluations were
conducted at 31 sites.
6. Three stream fisheries assessment s were completed to evaluate the fish
community at sites slated for habitat restoration by the Partners for Fish and
Wildlife Program (PFW).
7. PFW program identified restoration needs and opportunities for 10 areas.
8. Developed an Unpaved Road Evaluation Handbook.
9. Completed restoration of Chipola River Greenway, Seibenhener Streambank
Restoration, Blackwater River State Forest, and Anderson Property.
10. Assessments for fluvial geomorphic conditions for design criteria were completed
for 3 projects.
11. Geomorphology in Florida streams initiated development of Rosgen regional
curves for Northwest Florida for use by the Florida Department of Transportation.
12. Developed a Memorandum of Understanding between partners for enhancing,
protecting, and restoring stream, wetland, and upland habitat in northwest Florida
13. Completed aquatic fauna and fish surveys with new emphasis on integration of
data from reach level into watershed and landscape scale and keeping database
current.
14. Compliance based sampling of impaired waterbodies on Eglin Air Force Base in
conjunction with Florida Department of Environmental Protection for Total
Maximum Daily Load development support.
15. Surveyed 20 sites for the federally endangered Okaloosa darter, provided habitat
descriptions, worked with partners to implement key recovery tasks and set
priorities for restoration.
16. Worked with partners to develop a freshwater mussel survey protocol to provide
standard operating procedures for establishing the presence/absence of federally
listed mussel species within a Federal project area.
17. GIS database was created to identify all known freshwater mussel records from
the northeast Gulf ecosystem.
18. Completed recovery plan for seven freshwater mussels and drafted candidate
elevation package for seven additional mussels. Developed proposals to
implement recovery plan.
19. Worked with Corps of Engineers and State partners to develop improved reservoir
operating policies to benefit both riverine and reservoir fisheries for the ACF river
system.
20. Multiple outreach projects were completed to detail aquatic resources
conservation opportunities.
21. Multiple stream restoration and watershed management projects initiated or
completed (see Appendix A)
Developing a multi-metric habitat index for wadeable streams in Illinois (T-25-P-001), annual segment report to the Illinois Department of Natural Resources.
USFWS through IDNR State Wildlife Grant Grant/Contract No: T-25-P-001INHS Technical Report Prepared for USFWS through IDNR State Wildlife Gran
Developing a multi-metric habitat index for wadeable streams in Illinois (T-25-P-001). Annual Segment Report to the Illinois Department of Natural Resources.
Illinois Department of Natural Resources Grant/Contract No: (T-25-P-001)This project was initiated to describe key aquatic habitat characteristics and their association to anthropogenic disturbance by developing a field based, rapid assessment method for qualitatively monitoring instream conditions using a multi-metric habitat index. We have developed and applied a method for rating disturbance in wadeable streams throughout Illinois and collected information on physical habitat at 299 sites to date. Index development is in the preliminary stages with field work to continue during the summer of 2008. This report summarizes work performed for the period ending April 30, 2008 (Appendix A contains Eastern Illinois University subcontract annual report).INHS Technical Report Prepared for Illinois Department of Natural Resource
Evaluation of Potential Translocation Sites for an Imperiled Cyprinid, the Hornyhead Chub
Translocation of isolated species into suitable habitats may help to secure vulnerable, geographically limited species. Due to the decline of Wyoming Hornyhead Chub Nocomis biguttatus, conservation actions, such as the translocation of populations within the plausible historical range, are being considered to improve population redundancy and resiliency to disturbance events. Translocation of Wyoming Hornyhead Chub must be rigorously evaluated because a hatchery stock does not exist, so all fish used in translocations will come from the wild population. We present an approach to identify the best available translocation sites prior to translocation efforts taking place. We evaluated fish community composition and habitat conditions at 54 potential translocation sites for Hornyhead Chub within 12 streams of the North Platte River basin of Wyoming. We used two analyses to identify translocation sites that were most similar to currently occupied Hornyhead Chub sites on the Laramie River: hurdle models to predict hypothetical abundance of Hornyhead Chub at translocation sites and nonmetric multidimensional scaling with fish community and habitat conditions. Presence and abundance of Hornyhead Chub were positively related to a lack of nonnative predators and to habitat features characteristic of backwater and velocity refuge habitats (e.g., minimum water velocity and width-to-depth ratio). We used a rank scoring system to weight the outcomes of each analysis, and the highest-ranking translocation sites occurred at a historically occupied locality, the Sweetwater River. Our approach may be appropriate for other at-risk species with isolated distributions and little historical data
Ubiquitous Cell-Free Massive MIMO Communications
Since the first cellular networks were trialled in the 1970s, we have
witnessed an incredible wireless revolution. From 1G to 4G, the massive traffic
growth has been managed by a combination of wider bandwidths, refined radio
interfaces, and network densification, namely increasing the number of antennas
per site. Due its cost-efficiency, the latter has contributed the most. Massive
MIMO (multiple-input multiple-output) is a key 5G technology that uses massive
antenna arrays to provide a very high beamforming gain and spatially
multiplexing of users, and hence, increases the spectral and energy efficiency.
It constitutes a centralized solution to densify a network, and its performance
is limited by the inter-cell interference inherent in its cell-centric design.
Conversely, ubiquitous cell-free Massive MIMO refers to a distributed Massive
MIMO system implementing coherent user-centric transmission to overcome the
inter-cell interference limitation in cellular networks and provide additional
macro-diversity. These features, combined with the system scalability inherent
in the Massive MIMO design, distinguishes ubiquitous cell-free Massive MIMO
from prior coordinated distributed wireless systems. In this article, we
investigate the enormous potential of this promising technology while
addressing practical deployment issues to deal with the increased
back/front-hauling overhead deriving from the signal co-processing.Comment: Published in EURASIP Journal on Wireless Communications and
Networking on August 5, 201
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