Performance enhancement for AF relay MIMO/OFDM with complex HTRCI pilot signal
Yuta Ida, Chang-Jun Ahn, Takahiro Matsumoto, Shinya Matsufuji · 2014
Recently, amplify-and-forward (AF) multiple-input multiple-output (MIMO) relay transmissions are studied to achieve high quality communications. On the other hand, they have to estimate all channels between the source-relay and relay-destination nodes in the receiver. In MIMO orthogonal frequency division multiplexing (OFDM) systems, high time resolution carrier interferometry (HTRCI) has been proposed to achieve an accurate channel estimation (CE) with a small number of pilot signals. However, the conventional HTRCI-MIMO/OFDM is not adopted in AF relay transmissions. Therefore, in this paper, we propose the complex HTRCI (C-HTRCI) pilot signal to achieve an accurate CE for AF relay MIMO/OFDM systems.