Parallel Interference Cancellation Detector Research Articles

Multiuser Detection for Out-of-Cell Cochannel Interference Mitigation in the IS–95 Downlink

This paper considers the application of multiuser detection techniques to improve the quality of downlink reception in a multi-cell IS---95 digital cellular communication system. In order to understand the relative performance of suboptimum multiuser detectors including the matched filter detector, optimum multiuser detection in the context of the IS---95 downlink is first considered. A reduced complexity optimum detector that takes advantage of the structural properties of the IS---95 downlink and exhibits exponentially lower complexity than the brute-force optimum detector is developed. The Group Parallel Interference Cancellation (GPIC) detector, a suboptimum, low-complexity multiuser detector that also exploits the structure of the IS---95 downlink is then developed. Simulation evidence is presented that suggests that the performance of the GPIC detector may be near-optimum in several cases. The GPIC detector is also tested on a snapshot of on-air data measured with an omnidirectional antenna in an active IS---95 system and is shown to be effective for extracting weak downlink transmissions from strong out-of-cell cochannel interference. The results of this paper suggest that the GPIC detector offers the most performance gain in scenarios where weak downlink signals are corrupted by strong out-of-cell cochannel interference.

Impact of Imperfect Power Control and Channel Estimation on the Performance of Multiuser Detectors in Synchronous DS-CDMA System

Simulation performance comparison of various linear multiuser and parallel interference cancellation (PIC) detectors in the presence of imperfect power control and channel estimation is presented. ...

Determination of cancellation factors for soft-decision partial PIC detector in DS/CDMA systems

An alternative investigation has been carried out into the soft-decision partial parallel interference cancellation (SD-PPIC) detectors proposed by Divala et al. (1998) for DS/CDMA systems. A convenient method is presented for determining the partial cancellation factors in SD-PPIC detectors, which can ensure that the SD-PPIC detector converges at the maximum rate to its performance limit, which is proven to be equivalent to that of a decorrelating detector.