Impairment covariance and combining weight updates during iterative turbo interference cancellation reception

摘要

In a receive node of a wireless network, an iterative multi-user multi-stage interference cancellation receiver is used. After each stage of interference cancellation, interference characteristics change. An adaptive strategy is used in which after each stage of interference cancellation, impairment covariance is parametrically updated and combining weights of the receiver are adapted to reflect the updated impairment covariance.

主权项

1. A method performed in a receive node of a communication network, the receive node being structured to operate on a data stream transmitted from a transmit node, the method comprising:
performing, by the receive node, a first stage processing a symbol of interest contained in a first composite signal; and performing, by the receive node, a second stage processing the same symbol of interest contained in a second composite signal, wherein the first stage processing comprises:
determining a first stage impairment covariance estimate;determining one or more first stage combining weights based on the first stage impairment covariance estimate;performing a first stage equalization of the first composite signal based on the first stage combining weights to generate a first stage equalized signal;determining one or more first stage interfering symbol estimates based on the first stage equalized signal; andcanceling the first stage interfering symbol estimates from the first composite signal to generate an interference-reduced version of the first composite signal, and wherein the second stage processing comprises:
determining a second stage impairment covariance estimate based on the first stage impairment covariance estimate and one or more previous stage interfering symbol estimates; anddetermining one or more second stage combining weights based on the second stage impairment covariance estimate;performing a second stage equalization of the second composite signal based on the second stage combining weights to generate a second stage equalized signal, wherein the second composite signal is based on the interference-reduced version of the first composite signal, and wherein the previous stage corresponds to the first stage processing or to a previous run of the second stage processing.