Multi-rate LMMSE detectors for asynchronous multi-rate CDMA systems

This work is an extension of the multi-rate LMMSE detectors (Ge 1997) for asynchronous multi-rate CDMA systems. The proposed LMMSE detectors can work on dual-rate mode according to different quality-of-service (QoS) requirements and computational constraints. In using the proposed multirate LMMSE detectors, only the signature and timing information of the desired user are required. The proposed detectors can achieve better detection performance with less computation than the dual-rate decorrelating detectors. Adaptive schemes of implementing the proposed detectors can handle both synchronous and asynchronous channels as long as the signature and timing information on the desired user is available