Optimal power allocation scheme for distributed antenna system with OFDM in frequency-selective fading channels

• Published in: Electronics letters Vol. 54; no. 7; pp. 454 - 456
• Main Authors: Yu, Xiangbin, Wang, Hao, Leung, Shu-Hung, Teng, Tao
• Format: Journal Article
• Language: English
• Published: The Institution of Engineering and Technology 05.04.2018
• Subjects: antenna arrays; capacity maximisation; channel capacity; computer simulations; DAS‐OFDM; distributed antenna system with orthogonal frequency division multiplexing; fading channels; frequency‐selective fading channels; Karush– Kuhn–Tucker optimality conditions; largest channel gain; OFDM modulation; optimal PA scheme; optimal power allocation scheme; optimisation; transmit power optimisation; Wireless communications; optimal PA scheme; optimal power allocation scheme; channel capacity; transmit power optimisation; computer simulations; largest channel gain; DAS-OFDM; optimisation; fading channels; antenna arrays; distributed antenna system with orthogonal frequency division multiplexing; OFDM modulation; capacity maximisation; Karush– Kuhn–Tucker optimality conditions; frequency-selective fading channels
• ISSN: 0013-5194; 1350-911X; 1350-911X
• DOI: 10.1049/el.2017.4513

Optimal power allocation (PA) scheme for distributed antenna systems with orthogonal frequency division multiplexing (DAS-OFDM) over frequency-selective fading channels is presented. The PA design is to optimise the transmit powers of subcarriers to maximise the capacity subject to the total power constraint. Based on the Karush–Kuhn–Tucker optimality conditions, the optimal PA to the distributed nodes for a subcarrier can be simplified to allocating the power to the node of the largest channel gain. With this result, an efficient algorithm is derived to obtain the optimal PA to the nodes for all the subcarriers of the DAS-OFDM. Compared with an existing suboptimal scheme, the developed scheme can obtain higher capacity and has lower complexity. By computer simulations, the effectiveness of the proposed scheme is verified.