Informatics Publishing Limited

R. Mukunthan ¹, N. Sairam ¹

Affiliations
1 School of Computing, SASTRA University, Thanjavur, TamilNadu, IN

Abstract

A new method for detecting Delaunay edge by modifying the links in the star of a vertex is proposed. This is based on selecting vertex points of the input triangulation in such a way that the star formed from the selected point should belong to the given input set S. That star should not have any convex hull point and the edges connecting the selected vertex. The edges formed in the proposed method based on star formation are Delaunay edges since it satisfies the empty circle property. This is experimentally verified using two dimensional input data. Finally, Delaunay triangulation is obtained by joining the remaining edges which are validated and verified using the circumcircle property of Delaunay triangulation.

Keywords

Convex Hull, Delaunay Triangulation, Star Formation

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R. Mukunthan , V. Saranya

Abstract

Future mobile communication systems will adopt the multiple antennas at both transmitter and receiver to improve system capacity and spectral efficiency. In our proposed system a Per-chunk user scheduling with opportunistic feedback for multiple-input–multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) is considered. In this system we provide a solution for achievable throughput by grouping adjacent subcarriers into chunks, the amount of required feedback information is reduced. Based on the net throughput criterion, which accounts for the reduction in sum rate due to the feedback overhead, it is shown that there exists an optimal chunk size that maximizes the net throughput.  In which, for each chunk, only users with achievable rates higher than a predetermined threshold report back their rates. Analytical expressions for the net throughput are derived, which enable finding the optimum threshold that maximizes the average net throughput. The results show that increasing the total number of users in the system results in the net throughput of most existing MIMO-OFDM downlink schemes decreasing to zero for moderate-size user pools, whereas the net throughput of per-chunk user scheduling with opportunistic feedback increases with the total number of users even that number is very large.

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