Impact of Phase Errors on Distributed NTN Beam Focusing

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Nimr, Ahmad, Parvini, Mohammad, Banerjee, Bitan, Fettweis, Gerhard
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866916065239367680
author Nimr, Ahmad
Parvini, Mohammad
Banerjee, Bitan
Fettweis, Gerhard
author_facet Nimr, Ahmad
Parvini, Mohammad
Banerjee, Bitan
Fettweis, Gerhard
contents This paper investigates distributed beam focusing for coordinated satellite constellations with phased arrays, motivated by future non-terrestrial network (NTN) systems. A geometric and channel model is developed by incorporating satellite positions, array orientations, antenna directivity, and polarization effects. Under ideal synchronization, the achievable coherent combining gain is analyzed for different constellation geometries, showing that maximum ratio transmission (MRT) enables quadratic scaling of the received power with the number of satellites. The impact of phase errors caused by residual synchronization, timing, mobility, and localization mismatches is then investigated. Closed-form expressions for the average coherent gain are derived for uniformly distributed timing offsets, demonstrating the transition from coherent to non-coherent combining. The results show that synchronization and timing mismatches reduce the coherent combining gain, while geometry dependent effects govern the resulting spatial focusing behavior. Numerical results further show that linear and circular constellations provide different focusing characteristics and spatial separation capabilities. However, MRT-based focusing results in strong sidelobes and limited spatial division capability, motivating the need for joint analog beamforming and digital precoding optimization to improve spatial selectivity and robustness against mobility and localization errors.
format Preprint
id arxiv_https___arxiv_org_abs_2605_31180
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Impact of Phase Errors on Distributed NTN Beam Focusing
Nimr, Ahmad
Parvini, Mohammad
Banerjee, Bitan
Fettweis, Gerhard
Signal Processing
This paper investigates distributed beam focusing for coordinated satellite constellations with phased arrays, motivated by future non-terrestrial network (NTN) systems. A geometric and channel model is developed by incorporating satellite positions, array orientations, antenna directivity, and polarization effects. Under ideal synchronization, the achievable coherent combining gain is analyzed for different constellation geometries, showing that maximum ratio transmission (MRT) enables quadratic scaling of the received power with the number of satellites. The impact of phase errors caused by residual synchronization, timing, mobility, and localization mismatches is then investigated. Closed-form expressions for the average coherent gain are derived for uniformly distributed timing offsets, demonstrating the transition from coherent to non-coherent combining. The results show that synchronization and timing mismatches reduce the coherent combining gain, while geometry dependent effects govern the resulting spatial focusing behavior. Numerical results further show that linear and circular constellations provide different focusing characteristics and spatial separation capabilities. However, MRT-based focusing results in strong sidelobes and limited spatial division capability, motivating the need for joint analog beamforming and digital precoding optimization to improve spatial selectivity and robustness against mobility and localization errors.
title Impact of Phase Errors on Distributed NTN Beam Focusing
topic Signal Processing
url https://arxiv.org/abs/2605.31180