Finger placement in multi-stage interference cancellation
AssigneeTelefonaktiebolaget LM Ericsson (publ)
InventorsYi-Pin Eric Wang, Stephen Grant, Ning He, Niklas Johansson
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Abstract
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 finger placement strategy is used in which after each stage of interference cancellation, finger delays and combining weights of the receiver are adapted to reflect the changed interference characteristics.
Claims34
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 one or more first stage interference characteristics based on the first composite signal;
- determining one or more first stage processing delays based on the first stage interference characteristics;
- performing a first stage despreading and combining of the first composite signal based on the first stage processing delays to generate a first stage equalized signal;
- determining a first stage estimated signal based on the first stage equalized signal;
- canceling the first stage estimated signal from the first composite signal to generate an interference-reduced version of the first composite signal, and
- wherein the second stage processing comprises:
- determining one or more second stage processing delays;
- and
- performing a second stage despreading and combining of the second composite signal based on the second stage processing delays to generate a second stage equalized signal,
- wherein the second composite signal is based on the interference-reduced version of the first composite signal.
A receiver of a receive node of a communication network comprising a plurality of chains, each chain structured to process a symbol of interest contained in a first composite signal in a first stage, and to process the same symbol of interest contained in a second composite signal in a second stage, each chain of the receiver comprising:
- an equalizer;
- a demodulator;
- a signal regenerator;
- and
- an interference canceller,
- wherein in the first stage,
- the equalizer is structured to determine one or more first stage interference characteristics based on the first composite signal, to determine one or more first stage processing delays based on the first stage interference characteristics, and to perform a first stage despreading and combining of the first composite signal based on the first stage processing delays to generate a first stage equalized signal,
- the demodulator is structured to demodulate the first equalized signal to generate a first stage demodulated data,
- the signal regenerator is structured to determine a first stage estimated signal based on the first stage demodulated data, and
- the interference canceller is structured to cancel the first stage estimated signal from the first composite signal to generate an interference-reduced version of the first composite signal,
- wherein in the second stage, the equalizer is structured to determine one or more second stage processing delays, and to perform a second stage despreading and combining of the second composite signal based on the second stage processing delays to generate a second stage equalized signal, and
- wherein the second composite signal is based on the interference-reduced version of the first composite signal.
A non-transitory computer readable medium containing therein a program executable by a computer in a receive node of a communication network, when executed, the program causing the computer to perform a first stage processing a symbol of interest contained in a first composite signal, and to perform a second stage processing the same symbol of interest contained in a second composite signal,
- wherein the first stage processing comprises:
- determining one or more first stage interference characteristics based on the first composite signal;
- determining one or more first stage processing delays based on the first stage interference characteristics;
- performing a first stage despreading and combining of the first composite signal based on the first stage processing delays to generate a first stage equalized signal;
- determining a first stage estimated signal based on the first stage equalized signal;
- canceling the first stage estimated signal from the first composite signal to generate an interference-reduced version of the first composite signal, and
- wherein the second stage processing comprises:
- determining one or more second stage processing delays;
- and
- performing a second stage despreading and combining of the second composite signal based on the second stage processing delays to generate a second stage equalized signal,
- wherein the second composite signal is based on the interference-reduced version of the first composite signal.
Dependencies are inferred from the claim text.