Hybrid interference subspace rejection for multi-rate CDMA with improved performance/complexity tradeoff
Besma Smida, Sofiène Affes, Paul G. Mermelstein · 2006
Interference subspace rejection (ISR) offers a wide range of canonic suppression modes that range in performance and complexity between interference cancellers and linear receivers. In this paper, we propose a hybrid ISR scheme that, instead of suppressing all users with the same canonic ISR mode, splits them into several groups based on their datarates before applying different canonic ISR modes for their nulling. The resulting receiver provides a much better performance/complexity tradeoff. Simulations suggest that a hybrid of the two simplest canonic ISR modes performs almost as well as the more complex mode with 30 to 60% less complexity, while it outperforms the simpler of the two by several dB gains with minimal increase in complexity.