Vol.68, No.2, 2021, pp.2205-2219, doi:10.32604/cmc.2021.017008
OPEN ACCESS
ARTICLE
Improved Hybrid Precoding Technique with Low-Resolution for MIMO-OFDM System
  • Seulgi Lee1, Ji-Sung Jung1, Young-Hwan You2, Hyoung-Kyu Song1,*
1 Department of Information and Communication Engineering, and Convergence for Intelligent Drone, Sejong University, Seoul, 05006, Korea
2 Department of Computer Engineering, Sejong University, Seoul, 05006, Korea
* Corresponding Author: Hyoung-Kyu Song. Email:
Received 18 January 2021; Accepted 20 February 2021; Issue published 13 April 2021
Abstract
This paper proposes an improved hybrid beamforming system based on multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) system. The proposed beamforming system improves energy efficiency compared to the conventional hybrid beamforming system. Both sub-connected and full-connected structure are considered to apply the proposed algorithm. In the conventional hybrid beamforming, the usage of radio frequency (RF) chains and phase shifter (PS) gives high power and hardware complexity. In this paper, the phase over sampling (POS) with switches (SW) is used in hybrid beamforming system to improve the energy efficiency. The POS-SW structure samples the value of analog beamformer to make lower resolution than conventional system. The number of output data in POS is decided by the resolution of POS system. The limited number of POS decides the resolution of antenna array and the values of POSs are designed from maximum and minimum phase angle antenna array. Energy efficiency without the phase shifter is high although channel capacity is nearly similar with conventional system. Also, the amplifier with POS-SW system is proposed to improve the BER performance. According to the data bits, the output signals of POS are decided. The system with 2, 3 and 4 bits is simulated to prove the proposed algorithm. In order to overcome the loss of low-resolution system, the amplifier with POS-SW system using channel information is proposed. The average sum-rate of 4 bits system shows the similar performance with the conventional hybrid beamforming system. This structure can play an important role by increasing the energy efficiency of the wireless communication system that many antennas are used. It is shown that the BER, average sum rate and energy efficiency of the proposed scheme are more improved than the conventional hybrid beamforming system.
Keywords
Hybrid beamforming; MIMO-OFDM system; analog precoding; POS-SW
Cite This Article
S. Lee, J. Jung, Y. You and H. Song, "Improved hybrid precoding technique with low-resolution for mimo-ofdm system," Computers, Materials & Continua, vol. 68, no.2, pp. 2205–2219, 2021.
This work is licensed under a Creative Commons Attribution 4.0 International License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.