We investigate an orthogonal frequency-division multiplexing (OFDM)-based downlink transmission scheme for large-scale multi-user (MU) multiple-input multiple-output (MIMO) wireless systems. The use of OFDM causes a high peakto-average (power) ratio (PAR), which necessitates expensive and power-inefficient radio-frequency (RF) components at the base station. In this paper, we present a novel downlink transmission scheme, which exploits the massive degrees-of-freedom available in large-scale MU-MIMO-OFDM systems to achieve low PAR. Specifically, we propose to jointly perform MU precoding, OFDM modulation, and PAR reduction by solving a convex optimization problem. We develop a corresponding fast iterative truncation algorithm (FITRA) and show numerical results to demonstrate tremendous PAR-reduction capabilities. The significantly reduced linearity requirements eventually enable the use of low-cost RF components for the large-scale MU-MIMO-OFDM downlink. Index Terms-Convex optimization, multi-user wireless communication, multiple-input multiple-output (MIMO), orthogonal frequency-division multiplexing (OFDM), peak-to-average (power) ratio (PAR) reduction, precoding.
The authors in REF presented a low peak-to-average-power ratio (PAR) precoding solution to enable efficient implementation using non-linear RF components in massive MIMO system.
PAR-Aware Large-Scale Multi-User MIMO-OFDM Downlink
IEEE Journal on Selected Areas in Communications
IEEE Journal on Selected Areas in Communications
Mathematics Computer Science