TIE - Trellis-based reduced state data detection in quantum optical telecommunications

TIE is a system for trellis-based data detection with reduced state count, which is particularly important for modern wireless communication systems. Conventional detection methods quickly reach their limits, especially in scenarios with strong multipath propagation and intersymbol interference, such as those encountered in mobile communications or wireless optical quantum communication systems. Although proven trellis-based algorithms such as the Viterbi algorithm or the BCJR algorithm (log-MAP) are optimal for symbol-by-symbol or sequential detection in such channels, their complexity increases exponentially with the number of transmission paths, which makes their practical implementation difficult. 

To solve this problem, the invention specifically reduces the number of trellis states to be considered. This is done by making preliminary decisions about data symbols during detection, which makes it possible to reduce the number of states in each step. In this way, detection remains robust against interference, while implementation costs and computing effort are significantly reduced.

At its core, TIE consists of a receiving unit that receives transition metrics, a processing unit that makes preliminary decisions based on these values, and an output unit that provides these results for further processing. The solution is complemented by integrated decision feedback equalization (DFE), which allows a priori information such as log likelihood ratios to be incorporated to further optimize data detection.