What is a channel Chart?

The channel chart has the key property that nearby points correspond to nearby locations in real space. The above figure shows channel charting results obtained from real-world measurements (240,000 CSI samples) acquired with a 32-antenna BS operating at 2.5 GHz.

How does channel charting work?

Channel charting learns a mapping from channel state information (CSI) to a so-called channel chart in which nearby datapoints indicate nearness in real space. In other words, the learned channel chart captures the nearby spatial geometry of the transmitting user equipments (UEs), effectively encoding relative (or logical) UE locations.

Is channel charting self supervised?

Channel charting is self-supervised as the mapping from CSI to the channel chart is learned only using a database of passively collected CSI information. Such a data-driven localization approach has the advantages of being scalable and avoiding reference location information, e.g., from global navigation satellite systems (GNSSs).