Deliberate Clipping and Iterative Distortion Recovery for UCA-Based OAM Multiplexing Systems

Norifumi Kamiya

doi:10.1109/access.2021.3138738

Abstract

Deliberate Clipping and Iterative Distortion Recovery for UCA-Based OAM Multiplexing Systems

Highlights

INTRODUCTIONRadio orbital angular momentum (OAM) multiplexing transmission [1], [2] has recently attracted attention for application to high-capacity wireless communication systems, especially to point-to-point (PTP) line-of-sight (LOS) millimeter wave radio systems for mobile fronthaul and backhaul links [3]–[8]
Radio orbital angular momentum (OAM) multiplexing transmission [1], [2] has recently attracted attention for application to high-capacity wireless communication systems, especially to point-to-point (PTP) line-of-sight (LOS) millimeter wave radio systems for mobile fronthaul and backhaul links [3]–[8].OAM multiplexing is realized with electromagnetic waves of different OAM modes, which are inherently orthogonal to each other
Unless stated otherwise, the number of antenna elements N was set to 8; the distance separating the Tx and Rx antennas was set to 40 m; the carrier frequency was set to 84.5 GHz; and the radius of the uniform circular array (UCA) was set to 0.265 m

Summary

INTRODUCTION

Radio orbital angular momentum (OAM) multiplexing transmission [1], [2] has recently attracted attention for application to high-capacity wireless communication systems, especially to point-to-point (PTP) line-of-sight (LOS) millimeter wave radio systems for mobile fronthaul and backhaul links [3]–[8]. N. Kamiya: Deliberately Clipping and Iterative Distortion Recovery for UCA-based OAM Multiplexing Systems peak-power issue of the digital beamforming approach, in which the OAM signals are generated from baseband signals obtained by pre-coding N independent signals using a DFT matrix. The free space transmission model (e.g., [11]) is used to simulate an UCA-based OAM channel, in which the transfer function between a pair of Tx and Rx antenna elements is given by λ. The channel output signals received at the Rx N -UCA are filtered by RRCFs, down-sampled, and post-processed by performing an N - point DFT. Where r(k)[n] denotes the n-th (downsampled) output signal of the k-th RRCF and w(k)[n] is complex white Gaussian noise, w(k)[n] ∼ CN (0, σ2)

INSTANTANEOUS SIGNAL POWER OF UCA-BASED OAM SIGNALS

DELIBERATELY CLIPPING FOR PEAK POWER

SIMULATION RESULTS

CONCLUSION