Channel Estimation Based on Pilot Frequency Division Multiplexing for Distributed Space-Frequency Coded Cooperative Communication System

In this paper, both the least square (LS) and the low rank linear minimum mean square error (Lr-LMMSE) frequency-domain channel estimation algorithms based on pilot frequency division multiplexing are proposed for the distributed space-frequency (SF) coded cooperative communication system with multiple relay nodes, where both the channels from the source node to the relay nodes and from the relay nodes to the destination node are characterized by frequency-selective fading. Theoretical analysis shows that the proposed algorithms achieve all the frequency-domain channel fading coefficients of the multi-relay distributed SF coded cooperative communication system successfully and avoided the superposition of the pilot symbols transmitted by different relay nodes. Simulation results confirm the performance of the proposed channel estimation algorithms, including the high accuracy, extraordinary practicality and the low complexity.