Space-time signal processing utilizing multistep joint detection for the uplink of time division CDMA

In the TDD mode of UTRA (UMTS Terrestrial Radio Access) and IMT-2000 (International Mobile Telecommunications-2000) the multiple access scheme TD-CDMA (time division CDMA) is utilized. The preferred mode of detection in TD-CDMA is joint detection (JD). In this paper, a new multistep joint detection (MSJD) approach for TD-CDMA is presented, which allows an enhancement of the spectrum efficiency by improving the receiver performance especially in scenarios with the number of simultaneous connections, i.e. the system load, being close to the spreading factor. It is further shown that this MSJD approach can be easily combined with adaptive array processing in the uplink of TD-CDMA, where it can benefit from the advantage of adaptive arrays.