MIMO-OFDM-Based Wireless-Powered Relaying Communication With an Energy Recycling Interface

Abstract

This paper considers wireless-powered relaying multiple-input-multiple-output (MIMO) communication, where all four nodes (information source, energy source, relay, and destination) are equipped with multiple antennas. Orthogonal frequency division multiplexing (OFDM) is applied for information processing to compensate the frequency selectivity of communication channels between the information source and the relay and between the relay and the destination as these nodes are assumed to be located far apart each other. The relay is equipped with a full-duplexing interface for harvesting energy not only from the wireless transmission of the dedicated energy source but also from its own transmission while relaying the source information to the destination. The problem of designing the optimal power allocation over OFDM subcarriers and transmit antennas to maximize the overall spectral efficiency is addressed. Due to a very large number of subcarriers, this design problem poses a large-scale nonconvex optimization problem involving a few thousand variables of power allocation, which is very computationally challenging. A novel path-following algorithm is proposed for computation. Based on the developed closed-form calculation of linear computational complexity at each iteration, the proposed algorithm rapidly converges to an optimal solution. Compared to the best existing solvers, the computational complexity of the proposed algorithm is reduced at least 10 5 times, making it really efficient and practical for online computation while that existing solvers are impotent. Numerical results for a practical simulation setting show promising results by achieving high spectral efficiency.

Joint Transceiver Optimization for DF Multicasting MIMO Relay Systems With Wireless Information and Power Transfer

“…A practical two-phase MIMO-OFDM communication system with a wireless-powered full-duplex relay has been considered in [18], where a dedicated energy source is placed for the relay node to harvest sufficient energy. Furthermore, jointly optimal source and relay precoding matrices design in SWIPT AF MIMO relay systems to maximize the system data rate has been studied in [19]- [21].…”

“…We first study the power constraint at the relay node by checking the right-hand side of ( 11) and (18). We choose N = 3, d = 1, and L = 2.…”

“…Figs. [15][16][17][18][19] indicate that it is important to consider E m when choosing the optimal location of the relay node. Theoretical analysis on the choice of the location of the relay node is shown in Appendix C. Fig.…”

Estimation of bit error rate in 2×2 and 4×4 multi-input multi-output-orthogonal frequency division multiplexing systems

“…The MIMO-OFDM [3], [4] system enhances performance and channel capacity, ensuring that mobile communication is safe and secure. Space-time block coding (STBC) is used in wireless communication to send numerous copies of the data stream through many antennas and to improve data transfer accuracy by identifying different versions of the data received.…”

Kalman Filter Channel Estimation in 2 × 2 and 4 × 4 STBC MIMO-OFDM Systems

“…OFDM technology could transform the frequency selective fading channel into multiple flat fading sub-channels, which has the advantages of high spectral efficiency, simple implementation, and effective resistance to narrowband interference and multipath fading. Combining MIMO technology with OFDM technology can make full use of wireless resources in time, frequency, and space domain [6]. At the same time, MIMO-OFDM technology improves the system capacity and performance, which can provide a strong guarantee for 5G mobile communication.…”