Transmission delay control for SFN-OFDM multi-base-station in a cell using position information

摘要

In this paper, a system with "Multi-Base-Station in a Cell" using Single Frequency Network (SFN) Orthogonal Frequency Division Multiplex (OFDM) is proposed as a basic concept of the forth generation mobile system. The proposed system image consists of several cells in a larger cell and it works as follows: first, S-BS (Sub-Base Station) is set to transmit partially on the place where received signal power is below the desired one, because of increase of path loss while operating in high frequency, and under shadowing; secondly, BS (Base Station) and S-BSs transmit the same information by SFN-OFDM, so paths having in good condition may exist. However, at a receiver the timing offset in arrival between paths of BS and S-BSn leads to the inter-symbol interference (ISI). So "Transmission Delay Control" scheme using position information from Global Positioning System (GPS) is also proposed. We discuss usefulness of the proposed system against path loss increase and shadowing, and furthermore confirm that the proposed scheme is effective in operation at high speed rate.