Fast FDTD analysis of MIMO channel using spread spectrum technique

This paper proposes fast FDTD (Finite-Difference Time-Domain) analysis method that uses simultaneous excitation for multi-antenna systems. In this method, spread spectrum technique is employed for maintaining the orthogonality among the excited signals. Excitation signals are generated by multiplying the spreading codes that are different to each other. By assigning the different spreading codes to all transmitting antennas, the channels from multiple transmitting antennas to receiving antenna(s) can be calculated simultaneously. The simulation of a 2×2 multi-antenna system shows that the results of the proposed method agree well with those of the conventional method even though its computation speed is two times higher than that of the conventional method.