CORRELATION ANALYSIS ON MIMO-OFDM CHANNELS IN POPULATED TIME VARYING INDOOR ENVIRONMENT

The use of multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) has been considered for the physical layer transmission scheme of the next generation wireless communication systems (e.g. [1]). Accurate analysis and modelling of practical MIMO-OFDM channels are important in designing and optimising this transmission scheme. In indoor environment, pedestrian movement is known to cause significant effects on MIMO channels [2]. However, only a few measurement results concerning these effects have been reported in the literature. In this paper, time variation characteristics due to pedestrian movement are reported based on measured MIMO-OFDM channels at 5.2 GHz band with 40 MHz bandwidth. In particular, correlation of MIMO sub-channels (for example between the channels from transmitter (Tx) 1 to receiver (Rx) 1 and from Tx 1 to Rx 2, and so on) are analysed. The measurements were performed in an office environment by MIMO-OFDM channel sounder developed by CSIRO ICT Centre equipped with four transmitters and four receivers [3]. Two types of pedestrian configuration were considered: pedestrians standing in the middle between Tx and Rx and pedestrians walking and crossing the direct path between Tx and Rx. Both line-of-sight (LoS) and non LoS (NLoS) paths were analysed. The number of pedestrians ranges from zero to three. I