Novel Channel Estimation and Equalization Algorithms for Orthogonal Time-Frequency Space Modulation with Double Cyclic Prefix

In this manuscript, a digital communication system employing the orthogonal time-frequency space modulation with a double cyclic prefix and operating over a doubly selective fading is considered. After providing some guidelines for the allocation of pilot symbols within a single orthogonal timefrequency space modulation symbol, novel algorithms for pilotaided channel estimation and equalization are illustrated. The proposed channel estimator is able to provide a description of the inner structure of the communication channel; therefore, it can be also employed at the transmit side for sensing applications. Our numerical results evidence that our algorithms outperform two technical alternatives outlined in the literature at the price of a limited increase in the required computational effort.