Cognitive repeaters for flexible mobile data traffic offloading

We investigate the performance of cognitive amplify-and-forward (AF) repeaters in a dense urban environment. The benefit of repeaters is twofold. First, repeaters can compensate penetration losses and serve as wireless backhauling technology to bring high data rates into shielded environments. Second, a cognitive repeater can utilize very flexible different frequency bands and adopt its wireless link to the current frequency reuse plan. In this paper, we propose a new cognitive repeater concept which utilizes multiband signal offloading. Therefore, a cognitive repeater is implemented as a real-time hardware prototype in an amplify-and-forward (AF) relay and deployed in a real LTE-A testbed. The system performance is evaluated by various measurement trials within shielded indoor hotspot environments. It is shown, that cognitive repeaters can take advantage of the signal shielding to the outside and beneficially improve system performance for indoor user hotspots.