This paper introduces a multicarrier communication technique termed orthogonal chirp-frequency division multiplexing (OCFDM). It relies on a unitary transform named discrete modular chirp transform. The proposed OCFDM amalgamates characteristics from the orthogonal frequency division multiplexing (OFDM) and orthogonal chirp division multiplexing (OCDM), partitioning the frequency spectrum into distinct subbands and populating each of them with orthogonal chirps. By deriving the reconstructed signal at the receiver, the paper shows that the normalized signal-to-noise ratio exhibits changes across subbands, allowing the use of resource allocation, for instance, for power allocation or bit-loading. Moreover, it is shown that the OCFDM introduces an additional degree of freedom through its tile geometries, allowing it to be configured to perform in between OFDM and OCDM and, consequently, to offer novel and balanced trade-offs among symbol error rate, data rate, and robustness to interference. Numerical analyses illustrate those trade-offs and confirm the versatility and efficacy of the OCFDM.

This paper proposes the hybrid power line/wireless system (HPWS) based on the orthogonal chirp-division mul-tiplexing (OCDM) scheme. In this system, the same discrete- Fresnel domain symbols are transmitted through power line and wireless channels, enabling the application of combining techniques in the same domain and hence the signal-to-noise ratio increase at the receiver side. Furthermore, the optimal power allocation for maximizing the achievable data rate or minimizing the average bit error probability is discussed for OCDM-based HPWS. Finally, numerical analyses demonstrate that the OCDM- based HPWS is more appropriate for minimizing the average bit error probability if the transmitter is unaware of the channel state information.

This paper advances the studies regarding inter-ference caused by the cyclic prefix violation and the symbol timing offset in data communication schemes applied to power line communication systems. In this sense, it is shown that a few closed-form expressions can be used to characterize the orthogonal Stockwell division multiplexing (OSDM) scheme, as long it follows a couple of conditions. Moreover, the OSDM is compared to the Hermitian symmetric orthogonal frequency division multiplexing (HS-OFDM) scheme in terms of data rate and bit error probability (BEP) while contemplating narrowband power line channels corrupted by an additive colored Gaussian noise. The numerical results show that the OSDM performs better in terms of data rate than the HS-OFDM when interference affects the data communication system. In addition, the OSDM also surpasses the HS-OFDM in terms of BEP when the data communication system operates without interference or weak interference.