MIMO Communications using Trellis-based Channel Estimation

Motivated by the consideration of pilot overhead reduction for Multiple-Input Multiple-Output (MIMO) communications, we present a trellis-based joint channel and data estimation approach in this paper. The trellis tracking algorithm allows to estimate multiple channel coefficients in parallel while simultaneously performing a posteriori Probability (APP) detection of the transmitted bits. Different methodologies are compared with each other. The trellis-based joint data and channel estimation can yield adequate performance even with very sparse conventional discrete pilots under fast fading environment. Alternatively, superimposed pilots can further reduce the overhead and adapt to even faster fading. Furthermore, trellis tracking allows us achieve equivalent high performance, by deploying Differential Phase Shift Keying (DPSK) signal across multiple antenna channels even without any pilots at all.