Iterative Interference Cancellation Using Mixed Feedback Weights and Stabilizing Step Sizes

Abstract

A receiver is configured for canceling intra-cell and inter-cell interference in coded, multiple-access, spread-spectrum transmissions that propagate through frequency-selective communication channels. The receiver employs iterative symbol-estimate weighting, subtractive cancellation with a stabilizing step-size, and mixed-decision symbol estimates. Receiver embodiments may be implemented explicitly in software or programmed hardware, or implicitly in standard Rake-based hardware either within the Rake (i.e., at the finger level) or outside the Rake (i.e., at the user or sub channel symbol level).

1 . An interference canceller configured for computing interference-cancelled symbol estimates, and performing processing during each of at least one iteration, the canceller comprising a decision module, the decision module configured for processing each of one or more input symbol estimates for producing one of a hard decision or a soft decision, and a de-biasing module configured for scaling the input symbol estimates with a scale factor to remove bias computed on the input symbol estimates for producing de-biased input symbol estimates.