Wideband Direct Satellite Uplink Enabled by Pilot-less Sparse Superposition Codes

TL;DR

This paper introduces a pilot-less sparse superposition coding scheme for wideband satellite uplinks, improving throughput and resource utilization in coverage-limited scenarios.

Contribution

It proposes a novel pilot-less coded modulation scheme using structured Zadoff-Chu dictionaries and a multi-codeword framework with feedback for efficient wideband satellite communication.

Findings

Achieves higher throughput than conventional narrow-band approaches.

Supports scalable transmission with structured Zadoff-Chu dictionaries.

Enables reliable communication with reduced decoding complexity.

Abstract

Direct satellite uplink is severely constrained by limited link budgets, which hinder the exploitation of wideband resources, and ultimately limit the throughout. This paper presents a pilot-less coded modulation scheme based on sparse superposition coding (SSC) to enable efficient wideband usage in coverage-limited scenarios. This scheme leverages the structured Zadoff-Chu quasi-orthogonal (ZC-QO) dictionary to support scalable transmission. To address decoding complexity, the SSC transmitted signal embeds root index information via indicator sequences, allowing the receiver to restrict the decoding search space. In addition, a multi-codeword transmission framework with repetition and stop-feedback is developed, enabling reliable communication and better resource utilization. Simulation results show that the proposed scheme achieves throughput gains compared to a more conventional narrow-band multi-dimensional constellation-based approach.