On the capacity of a cellular TDD-CDMA system employing frequency channel assignment schemes

Because of multi-user detection (MUD) and discontinuous transmission in TDD-CDMA uplink (UL) system, the well-known formulation of UL background noise rise (BNR) for FDD-CDMA doesn´t adapt to TDD-CDMA. This paper discussed a modified BNR formulation for UL system capacity and load when multi-carrier is involved in the TDD-CDMA cellular network. Additionally, frequency allocation algorithms (FAAs) are described for TDD-CDMA system, and some dynamic slow-frequency hopping (DSFH) algorithms, which are based on the rapid frequency quality measurements, are proposed to enhance spectral efficiency and improve system capacity. In our work, the performance of various FAAs and DSFH algorithms are evaluated and compared by system level simulator. The simulation results show that the UL capacity and load can be estimated by the modified BNR formulations. Furthermore, the least BNR FAA is one of the most suitable FAA schemes and C/I based DSFH can provide more gains than other DSFH schemes.