Field trial results on uplink joint detection for moving relays

Public transportation vehicles are natural hotspots of wireless communication demand. Potentially, multiple users in the vehicle will compete for scarce spectral resources. At the same time, the direct link of users in the vehicle to the base stations might be rather week due to a high indoor-outdoor penetration loss. A potential solution to these this is the use of multi-antenna relays with antennas outside the vehicle for communication with the base stations and inside the vehicle for communication with the users. In order to increase the throughput on the base station - relay link, especially at cell edges, coordinated signal processing of multiple base stations could be used. In this work, we explore the performance of this approach in an uplink large-scale field trial of a multi-antenna transmitter carried on a measurement bus in an urban cellular environment. For this setup we show achievable data rates using linear and non-linear detection and explore the gain of joint detection in cooperation clusters of up to three base stations.