New insights in optimal pilot symbol patterns for OFDM systems

Nowadays, most wireless communication systems utilize coherent detection which implies the necessity of multiplexing reference symbols between data-symbols for the purpose of channel estimation. In Long Term Evolution (LTE), these reference symbols can consume up to 14.2% of the total bandwidth. In this work, we search for an optimal pilot-symbol pattern design using a post-equalization Signal to Interference and Noise Ratio (SINR) framework. We show how close to optimally choose the distance between adjacent pilot-symbols and how to distribute the available power between pilot and data symbol at the same time. We confirm the performance of our analytical solution by means of simulation. Compared to a system with a fixed distance between pilot-symbol and unit power distribution, the proposed system configuration yields a gain of around 30% in terms of capacity.