Evaluation of relay transmission in outdoor-to-indoor propagation channels
Katsuyuki Haneda, V-M. Kolmonen, Taneli Riihonen, Risto Wichman, P. Vainikainen, Jun‐ichi Takada · 2008
This paper investigates the performance of relay transmission against real-world propagation channels. The investigation focuses on outdoor-to-indoor communication links where a relay terminal provides enhanced data transmission capability for indoor receivers (Rx) by forwarding signals from outdoor base station. Real-time channel sounder was used to measure three links constituting the relay transmission: source-relay, sourcedestination, and relay-destination links. Amplify-and-forward (AF) and decode-and-forward (DF) methods were considered for signal relay schemes. Evaluation of end-to-end channel capacity revealed the following conclusions: 1) introducing relay in outdoor-to-indoor radio link extends the BS coverage around the relay terminal; 2) relay improves outage capacity better than mean capacity; 3) DF achieves twice the capacity improvement of AF on average when destination terminals are around the relay terminal; and finally, 4) power adaptation enhances the system performance, but the effect is minor.