B. R. JI ANG ET AL.
Copyright © 2013 SciRes. CN
Table 5 shows the computational complexity of the
four algorithms. We can easily learn that the complexity
of ma x-rate algorith m is
O KN, and the complexity of
PF and Qos algo rithm a r e all
. For the proposed
algorithm , th e c ompl exity of initial allocation is
,
and the complexity of re-allocation scheme is
O KN,
Therefore, the overall complexity of proposed algorithm
is
O KNOKNO KN+= . It is observed that, the
proposed algorithm gains the quadratic complexity,
which is the same as that of PF and Qos algorithm. The
last column of Tabl e 5 explains that the max-rate algo-
rithm gets the lowest computational complexity, and the
other three algorithms have the same computational
complexity.
5. Conclusions
In this paper, we propose a two-step resource block allo-
cation algorithm for LTE downlink systems. The first
step of pro posed algorithm initiall y allocates AUs to each
user based on the proportional fairne ss sc he me. The n, t h e
proposed scheme re-allocates the AUs with the worst
channel condition of each user to improve the perfor-
mance restriction by those AUs. The algorithm can pro-
vide us with a higher data rate and a flexible allocation
scheme, and ensures the user's fairness. Simulation re-
sults show that the proposed algorithm provides higher
thro ughput and ens ures the fairness of each user.
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