Interference Cancellation via Energy Detection and DM-RS

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Solution Overview

Problem

Current wireless communication systems face challenges in effectively detecting and cancelling interference, particularly in environments with low signal-to-interference ratio (SIR) and higher constellations, where existing mechanisms like interference aware maximum ratio combining (IRC) and backhaul connections are unreliable.

Innovation Solution

A method that performs energy level detection to determine the allocation size and position of an interfering device, identifies the interference demodulation reference signal (DM-RS) and cyclic shift, and applies successive interference cancellation based on these parameters to cancel interference from the interfering device.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If interference aware maximum ratio combining (IRC) detection is used to cancel interference, then interference cancellation is achieved, but it does not work effectively in environments with signal-to-interference ratio (SIR) below a threshold and/or at higher constellations

Engineering Contradiction:

Improveinterference cancellation effectivenessVSAvoidapplicability to low SIR and high constellation environments

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent changes the detection approach by using energy detection to determine allocation size and position of interfering devices, and using DM-RS and cyclic shift information to adapt the interference cancellation process to different SIR conditions and constellation types, making the system effective in low SIR and high constellation environments where IRC fails

Inventive Principle:

Principle #35Parameter changes

2Loss of information

If backhaul connections are used to communicate interferer information among base stations, then interference information can be shared, but the backhaul connection may not be guaranteed between any base stations and thus cannot be relied upon in all instances

Engineering Contradiction:

Improveinterference information sharingVSAvoidavailability of backhaul connection

Core Design Contradiction:

Loss of informationVSReliability

Solution Approach 1:

The patent enables base stations to autonomously detect interference signals and determine allocation parameters (allocation size, position, DM-RS, cyclic shift) without requiring backhaul communication. Each base station independently performs energy detection and interference cancellation, making the system reliable even when backhaul connections are unavailable

Inventive Principle:

Principle #25Self-service

Data Source

PatentEP3406062B1Techniques for detecting and cancelling interference in wireless communications

Publication Date: 2020.02.19 QUALCOMM INC

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AI summary

Various aspects described herein relate to cancelling interference in wireless communications. Energy level detection of a received signal can be performed to determine an allocation size and position corresponding to an interfering device in the received signal. An interference demodulation reference signal (DM-RS) and cyclic shift of the interfering device in the received signal can be determined. It can be determined whether to apply successive interference cancellation on the received signal, based at least in part on the allocation size and position and the DM-RS and cyclic shift, to cancel interference from the interfering device.