Adjacent Channel Compatibility Evaluation and Interference Mitigation Technique Between Earth Station in Motion and IMT-2020

Hyun-Ki Kim,Yeongi Cho,Han-Shin Jo

doi:10.1109/access.2020.3039799

Abstract

The millimeter wave band is becoming popular for mobile broadband usage such as fifth-generation (5G) mobile and mobile satellite services utilizing earth stations in motion (ESIM). According to the 2019 World Radiocommunication Conference (WRC-19), the 5G and ESIM systems will operate in adjacent frequency bands bounded by 27.5 GHz; therefore, the adjacent channel compatibility between ESIM and 5G should be verified. Both, the minimum coupling loss (MCL) and Monte-Carlo (MC) methods are applied to assess the worst and most practical interference effects, respectively, for all types of ESIM including the following: maritime ESIM (M-ESIM), land ESIM (L-ESIM), and aeronautical ESIM (A-ESIM). The distance and guard band between the two systems are indicated by the compatibility conditions. In addition to the conventional interference-to-noise ratio ( $I/N$ ), the throughput loss of a 5G system is proposed to assess the performance degradation caused by the ESIM interference. Two orthogonal frequency division multiplexing (OFDM) waveforms are proposed to suppress ESIM power leakage into an adjacent channel. A mathematical expression regarding the power spectral density (PSD) and frequency dependent rejection (FDR) is derived for these waveforms, suggesting that the interference can be alleviated. A measured single carrier waveform of a commercial ESIM equipment is used as the benchmark against the proposed OFDM waveforms. The windowed OFDM is able to reduce the guard band by 50–77%. The results obtained for various elevation angles of the ESIM antenna are determined to be applicable to various regions globally.

Highlights

This study proposes two waveforms of the earth station in motion (ESIM) using the cyclic prefix (CP)-orthogonal frequency division multiplexing (OFDM) and the windowed-OFDM; it derives the frequency dependent rejection (FDR) according to the type of signal through a practical frequency response of the receiver modeling
For quantifying the interference reduction produced by the IMT-2020 receiver selectivity and ESIM transmitter OOB, a mathematical expression of the FDR for varying the guard band was derived, using the measured transmission spectrum of the actual ESIM and the practical receiver filter of the IMT-2020
The windowedOFDM has a higher FDR than the measured signal for all guard bands, the CP-OFDM has a higher performance in the guard band below 50 MHz

Summary

INTRODUCTION

When the ESIM transmits a signal to the FSS satellite, the link (a) indicates that the IMT-2020 network is receiving it, which is radio interference. Through the d3D, which is the (WG 4) [21] This is a network that communicates with BSs distance of the signal path, the path loss in the LOS and UEs based on 5G specification, which is essential for environment is calculated as follows: obtaining realistic interference analysis results. In IMT-2020 uplink, the BSs receive the interference of the UEs distributed inside other micro cells through the same path loss given in (4). A-ESIM is assumed to fly at a constant altitude and elevation angle At this time, considering the curvature of the circumference of the Earth, the maximum distance that the IMT-2020 can observe for the aircraft can be calculated.

INTERFERENCE ANALYSIS METHODOLOGY

SIMULATION PARAMETER AND RESULTS

CONCLUSION