An investigation of interference between UTRA-TDD and FDD system

Interference between the UTRA-TDD and FDD system is investigated. There are some specific interference modes in the TDD mode because the uplink and the downlink use the same frequency band in the TDD mode. The UTRA-TDD and the UTRA-FDD have severe adjacent channel interference if they use the adjacent carrier. Some simulations are done to study the interference. Impacts of four different interference instances were considered in the simulation. The impact on the UTRA-FDD uplink capacity is evaluated. Some interesting results are given from the simulations. The TDD and FDD base station can not be co-located if they use the adjacent frequency band between which the value of ACIR is below about 70 dB. The TDD and FDD cells can use the same frequency in some scenarios, which will increase the capacity, and utilize the underused UTRA-FDD uplink resources.