Principle and Performance of TTI Bundling For VoIP in LTE FDD Mode

Limited transmission power and short TTI length impose a bottleneck on LTE UL performance in a coverage-limited scenario. This paper presents an effective coverage enhancement mechanism called TTI bundling to boost uplink VoIP performance in LTE FDD mode. Performance evaluation for TTI bundling with VoIP traffic is carried out by semi-static system simulation, and the impact from different bundling options with different bundle size and packet delay budget is investigated. The simulation analysis proves that with proper bundle size, TTI bundling can enhance the coverage performance for LTE FDD effectively.