Wideband Direct Satellite Uplink Enabled by Pilot-less Sparse Superposition Codes
This work addresses bandwidth constraints in satellite communications, but it appears incremental as it builds on existing sparse superposition coding methods.
The paper tackles the problem of limited link budgets in direct satellite uplink by proposing a pilot-less coded modulation scheme based on sparse superposition coding, which achieves throughput gains compared to conventional narrow-band approaches.
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.