A novel channel assignment approach in TDMA/CDMA-TDD systems

The interference in a TDD system is demonstrated as being comprised of two categories of interference: (1) same entity interference, which is base station (BS) to BS interference and mobile station (MS) to MS interference; (2) other entity interference which is BS→MS and MS→BS interference. Based on this specific TDD property, an equation for capacity in a CDMA/TDD system is derived. Moreover, it is shown that the capacity in a CDMA/TDD system can be significantly higher compared with an equivalent FDD system. This assumes use of a DCA algorithm. A novel DCA is presented which uses a newly developed method termed: time slot (TS) opposing technique. The main advantage of this technique is that a TDD system adopting different asymmetries for uplink and downlink in neighbouring cells does not necessarily suffer from capacity losses