The Algorithm for Blind Multi-user Detector Based on Subspace Tracking

Abstract

Multi-user detection (MUD) is an efficient technique for interference suppression that reduces the Multiple access interference (MAI) and improves the performance and increases the capacity of the system. Nowadays most of the research to MUD focuses on the blind multi-user detector because it does not require training sequences and can save the spectrum resource. By applying an improved subspace tracking algorithm to a modified subspace-based linear MMSE multi-user detector, a blind multi-user detector is presented. For the improved subspace tracking algorithm can reduce considerably computational complexity while keeping satisfactory convergence speed and stability and the modified MMSE multi-user detector doesn’t require the estimation of eigenvalue matrix, there can be significant elevation in the detection performance. Simulation results demonstrate preliminarily the conclusions above.

Keywords

• Blind multi-user detection (MUD)
• Multi-user access interference (MAI)
• Affine projection algorithm (APA)
• Subspace tracking.