Measuring Packet-Level Memory Length of 802.15.4 Wireless Channels with Relative Mutual Information

Measurement of a wireless channel´s memory length is of great, fundamental interest to designers of communication systems. The principal tool used for measuring the memory length of wireless channels has been the correlation function which has been shown to work well for the measurement of channel memory at the level of individual bits and symbols. However, as we demonstrate, applied to the packet-level bit-error process of 802.15.4 wireless channels, the correlation function fails to provide us with a clear answer even in a wide variety of channels. To overcome this limitation we propose the use of a new information theoretic measure. We introduce the use of relative mutual information and demonstrate its application for measuring the memory length of the BER process in sensor 802.15.4 wireless channels.