Semi-Analytical Model of Interference in CDMA-TDD Using Random Time Slot Hopping

In this paper, a semi-analytical approach for the performance analysis of the random time slot (TS) hopping (RTSH) algorithm applied to code division multiple access - time division duplex(CDMA-TDD) systems will be given. TDD systems are subject to two independent interference scenarios, giving rise to interference diversity, which is exploited by the RTSH algorithm. Depending on the actual slot assignment, the system either experiences same-entity interference (MS (mobile station)-to-MS and BS (base station)-to-BS interference) or other- entity interference (MS-to-BS and BS-to-MS interference). The RTSH algorithm results in a random switching between these two scenarios, each of which will result in a different level of interference. Thereby, constant severe interference is avoided. It has been shown that the RTSH algorithm results in lowest interference for channel asymmetries in favor of the downlink (DL).