Spread-spectrum frequency-hopping mobile location system

摘要

The system described in this paper is a frequency-hopped (FH) spread spectrum (SPSP) mobile location system operating also in an urban environment and using the unlicensed frequency band (ISM).The system consists of a central station (CS),a plurality of base stations (BS),and a plurality of mobile transmitters (MTs) which transmit modulated signals using differential binary shift keying (DBPSK) signal.The MT's transmission is received at the BS and using signal processing algorithms.the BS receiver estimates the direction of arrival (DOA) angle and its quality.This two parameters together with additional parameters are transferred to the CS.There,the CS collects the information of this transmission from all the BS.Using a location algorithm,the estimated position of the MT is displayed on a digital map.Using FH spread spectrum transmissions,multipath disruptions due to radio signals propagation in urban or irregular terrain environment are partially eliminated.The system presented herein is fully described at [5].