A Review on 6G Wireless Communication Systems: Localization and Sensing

The demand for multimedia data services has grown up rapidly over the years. Fifth generation (5G) wireless communication which has been deployed in a lot of countries will not be able to meet up with users demand based on the estimated mobile traffic volume of users in the next few years. Therefore, the sixth generation (6G) communication has been proposed to address the constraints/limitations of 5G communication. 6G systems will operate in the millimeter wave (mmWave) and terahertz region which has larger bandwidth and offers higher data rate than 5G systems. 6G has a lot of opportunities like high-definition imaging, frequency spectroscopy, accurate localization and sensing, which is the main focus of this work. There are a lot of opportunities for sensing at higher frequencies because of fine resolution in all physical dimensions (range, Doppler and angle). Moreover, localization and sensing in 6G is made possible by the key enablers technologies which are: the use of new radio band for communication, intelligent beam-space incorporation of intelligent surfaces, artificial intelligence and machine learning methods. In the new proposed 6G system, it is necessary for localization, sensing and communication to coexist, sharing the same time-frequency-spatial resources. In other to enable sharing, cooperation, coexistence and co-design, various mechanisms and approaches are needed in 6G communication systems.