Effects of rotation on the path loss and the delay spread in indoor infrared channel

A set of measurements for indoor infrared channel are reported. These measurements have been performed to investigate the effects of rotation on the parameters of the indoor infrared channel. A large database containing more than 5000 frequency responses has been created. The measurements have been performed in rooms with different shapes and physical properties to address all kinds of operating environments. This paper addresses parts of the results obtained from these measurements. The channel path loss and its delay spread are two important channel parameters for indoor infrared channel. The effects of receiver rotation on these two parameters have been studied. It is shown that the delay spread of the channel and its path loss are linearly correlated on the log scale when the receiver is rotated. The correlation between these two variables in different rooms and also different transceiver configurations remains an almost constant value close to unity. Therefore, we conclude that in general, when the receiver rotates, the logarithm of the delay spread of the channel changes linearly with the log of the channel path loss