Theoretical and Simulation Investigation on Coexistence between TD-SCDMA and WCDMA system

Universal Mobile Telecommunications Systems (UMTS) consist of two modes: UTRA-TDD and UTRA-FDD. The spectrum allocation is in such a way that both modes have an adjacent carrier at 1920 MHz. Due to the imperfection of transmitter and receiver hardware, adjacent channel interference (ACI) can not be completely avoided when both modes operate in 1920 MHz. In this paper, co-existence of UTRA-TDD low chip rate (TD-SCDMA) and UTRA-FDD (WCDMA) system is investigated. We use theoretical and simulation methods respectively to investigate the impact of TD-SCDMA and WCDMA when both operate in 1920 MHz. In the simulation method, we also research the influence of smart antenna which is deployed in TD-SCDMA system. Capacity loss is used to access the adjacent channel interference from TD-SCDMA base station (BS) to WCMA BS, then detailed theoretical and simulation results are presented, we give some useful suggestions for the deployment of the system based on our results.