On the Influence of Chirp Correlations upon OCFDM's Data Rate

Túlio F. Moreira, Wallace A. Martins, Moises Vidal Ribeiro

DOI: 10.14209/sbrt.2025.1571155396

Evento: XLIII Simpósio Brasileiro de Telecomunicações e Processamento de Sinais (SBrT2025)

Keywords: Correlation Multichirp Power allocation

Abstract

This paper takes the first step in exploiting the correlations between chirps to increase the data rate of orthogonal chirp-frequency division multiplexing (OCFDM) systems. To do so, the OCFDM system model is first revisited, and then its achievable data rate is written as a function of the correlated-signal-to-noise ratio (cSNR) matrix. A power allocation problem, termed optimal allocation (OA), is then formulated targeting data-rate maximization, resulting in a concave optimization problem, which can be readily solved via semi-definite programming. The numerical results show that chirp correlations can significantly boost data rate. Notably, under uniform power allocation, the performance becomes independent of the way the frequency tilings are defined, unlike the behavior under OA. In addition, OA tends to distribute power evenly among chirps within the same frequency tiling, termed voice, while still allowing flexibility across different voices, paralleling previously reported results when disregarding chirp correlations. Overall, the findings suggest that exploiting chirp correlations can play a key role in improving OCFDM's performance.

Download