Interference considerations for the time division duplex mode of the UMTS terrestrial radio access

Abstract

Abstract—The air interface of the UMTS Terrestrial Radio Access (UTRA) covers both a frequency division duplex (FDD) part for the paired bands and a time division duplex (TDD) part for the unpaired bands of the UMTS spectrum. Universal Mobile Telecommunication System (UMTS) is the 3rd-generation mobile communication system. This paper presents an interference eval-uation of the UTRA TDD. Since both uplink and downlink share the same frequency in TDD, the signals of the two transmission directions can interfere with each other. This interference can occur between two mobile stations or between two base stations within one carrier or between two operators. The interference between uplink and downlink is evaluated by system simulations in this paper. Synchronization and coordination requirements of UTRA TDD are evaluated based on the results. Index Terms—Network synchronization, time division duple