Orthogonal time frequency space (OTFS) is a novel scheme to combat the high Doppler effect under time-varying channel. In this paper, a pilot-aided channel estimation scheme based on Frank arrays, a matrix-form pilot structure, for multi-antenna OTFS systems is proposed for improving spectral efficiency. In the scheme, the pilots in delay-Doppler domain are constructed as several approximately orthogonal matrices based on Frank arrays. Different from the existing single pulse pilots and one-dimensional sequence pilots, these matrix-form pilots are placed on the same position on delay-Doppler domain, using code division multiplexing strategy to deal with the pilot pollution problem. Transceiver structures based on integer Doppler estimation are proposed, together with a simple but efficient threshold based channel estimation algorithm. It is shown via simulation results that, compared with the conventional multi-antenna OTFS schemes, the proposed scheme achieves better NMSE performance, while having low pilot overhead under the same conditions.
Pilot-Aided Channel Estimation Scheme Based on Frank Array for OTFS under Rapidly Time-Varying Channels
2022-06-01
383117 byte
Aufsatz (Konferenz)
Elektronische Ressource
Englisch