%0 Electronic Article
%A João Henrique Inacio de Souza
%A Taufik Abrão
%K multiple subchannels
%K hybrid Hughes-Hartogs power allocation algorithms
%K bit-allocation mechanism
%K transmission rate maximisation problem
%K power constraint
%K OFDMA systems
%K discrete solution
%K iteration updating
%K computational complexity analysis
%K greedy algorithms
%K initial allocation bit vector
%K water-filling solution
%K solution characterisation
%K complexity reduction mechanisms
%K HH solution
%K subchannel grouping procedure
%K system capacity
%X This work analyses the discrete solution of Hughes-Hartogs (HH) for the transmission rate maximisation problem with power constraint in the orthogonal frequency division multiplexing access (OFDMA) systems and explores mechanisms to reduce the computational complexity of greedy algorithms. In addition to the solution characterisation, a computational complexity analysis is developed, considering the number of executed operations for running time purpose. Moreover, the authors have compared the system capacity via the throughput obtained with the HH solution, and its variants combined with three complexity reduction mechanisms. These tools consist of an initial allocation bit vector calculated by rounding the results of the water-filling (WF) solution, the multiple subchannels per iteration updating and the adoption of a subchannel grouping procedure. Their findings indicate that the update of multiple subchannels and the subcarriers grouping techniques reduce the number of iterations required for convergence of the original HH, with some throughput degradation. Also, the bit-allocation mechanism based on the WF is deployed as an alternative to overcome the HH solution, increasing the computational complexity.
%@ 1751-9675
%T Hybrid Hughes-Hartogs power allocation algorithms for OFDMA systems
%B IET Signal Processing
%D December 2018
%V 12
%N 9
%P 1185-1192
%I Institution of Engineering and Technology
%U https://digital-library.theiet.org/;jsessionid=gdnof7p42b12.x-iet-live-01content/journals/10.1049/iet-spr.2018.5080
%G EN