Algorithm for Preliminary Processing Channel State Information of the WIFI Communication Channel for Building Indoor Positioning Systems

The work is devoted to the development of an algorithm for preprocessing channel state information of the WIFI communication channel for building indoor positioning systems. The relevance of the work is associated with the rapid growth of the market for mobile smart devices. The use of such devices requires higher positioning accuracy than existing methods and approaches can provide. In this regard, the problem solved in the framework of the study is an urgent scientific and technical problem. The paper proposes consideration of information about the channel state information, as opposed to the method of measuring the RSSI signal level, adopted in most radio positioning algorithms. Unlike RSSI, the link state information includes information about the signal transmitted on each of the subcarriers. The paper considers the WiFi4 standard with 56 sub carriers. The data packet contains information about the phase and amplitude of the signal. The study considers a technique for obtaining data on the channel state information, its collection, preprocessing and synchronization. The algorithms considered in the article make it possible to prepare initial, raw data for use in practical indoor positioning algorithms using data mining methods.