Title :
On the Concavity of the Sum-Rate Function in OFDM Systems
Author :
Jeonghee Chi ; Jieun Kim ; Youjung Ha ; Hyang-Won Lee
Author_Institution :
Dept. of Internet & Multimedia Eng., Konkuk Univ., Seoul, South Korea
Abstract :
We study the power allocation problem for maximizing the sum rate in orthogonal frequency-division multiplexing systems, where multiple point-to-point links share a set of subcarriers. This problem is hard to solve, in general, due to its nonconvexity. In this letter, we characterize the conditions for the problem to be convex, in which case the problem can be solved efficiently using known algorithms such as gradient projection method. We validate our analysis through simulations.
Keywords :
OFDM modulation; concave programming; gradient methods; radio links; OFDM systems; gradient projection method; multiple point-to-point links; nonconvexity; orthogonal frequency-division multiplexing systems; power allocation problem; subcarrier sets; sum-rate function concavity; Frequency division multiaccess; Interference channels; Linear programming; OFDM; Receivers; Transmitters; OFDM; concavity conditions; non-convex optimization; sum-rate function;
Journal_Title :
Communications Letters, IEEE
DOI :
10.1109/LCOMM.2014.2334323
