Pilot strategies for trellis-based MIMO channel tracking and data detection

In order to reduce pilot overhead for Multiple-Input Multiple-Output (MIMO) communications, we present a trellis-based joint channel tracking and data detection approach that allows reliable communications at fast fading rates. The trellis tracking algorithm predicts multiple channel coefficients in parallel while simultaneously performing a posteriori Probability (APP) detection of the transmitted bits. Different variants are compared based on different pilot training strategies, using discrete pilots, superimposed pilots, or no pilots at all by employing Differential Phase Shift Keying (DPSK) across multiple antenna channels.