Two-Stage Linear Nonlinear Interference Cancellation
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Solution Overview
Problem
Current wireless communication systems face challenges in effectively canceling interference in multiple-access systems, particularly in supporting simultaneous communication for multiple users, where interference from other users' signals can degrade the quality of received signals.
Innovation Solution
A two-stage linear/non-linear interference cancellation method is employed, utilizing a first linear interference canceller at the chip level and a second linear/non-linear interference canceller at the symbol level, which processes received signals to produce a descrambled signal and further refines it to generate a detected signal, improving interference cancellation performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple users communicate simultaneously in a multiple-access system, then system capacity and resource utilization improve, but interference from other users' signals degrades received signal quality
Solution Approach 1:
The interference cancellation process is divided into two distinct stages: a first stage that processes received signals to produce descrambled signals, and a second stage that processes descrambled signals to produce detected signals. Each stage uses appropriate cancellation techniques (linear IC in first stage, linear/nonlinear IC in second stage) optimized for its specific processing level, thereby effectively reducing multi-user interference while maintaining system capacity
Solution Approach 2:
The patent introduces an intermediary processing stage that generates descrambled signals as an intermediate representation between raw received signals and final detected signals. This intermediate stage allows for specialized interference cancellation processing that bridges the gap between initial signal reception and final detection, improving overall system performance in multi-user environments
2Reliability
If a single-stage interference canceller is used, then device complexity is reduced, but interference cancellation performance is insufficient
Solution Approach 1:
The interference canceller is segmented into two functional modules: a first interference canceller that operates on received signals using linear interference cancellation, and a second interference canceller that operates on descrambled signals using linear/nonlinear interference cancellation. This segmentation allows each module to be optimized for its specific task, achieving superior overall performance compared to a single-stage canceller while keeping individual module complexity manageable
Solution Approach 2:
The patent employs dynamic processing where the type of interference cancellation applied changes based on the processing stage: linear IC is used in the first stage for initial interference reduction, and linear/nonlinear IC is used in the second stage for refined cancellation on descrambled signals. This dynamic adaptation of cancellation techniques to different processing stages optimizes performance without requiring excessively complex hardware
Data Source
AI summary
An apparatus and method for a two-stage linear/nonlinear interference cancellation comprising processing a receive signal to produce a first descrambled signal; and processing the first descrambled signal to produce a detected signal. In one aspect, a first interference canceller module is used for processing the received signal and a second interference canceller module is used for processing the first descrambled signal. In one aspect, the first interference canceller is a linear interference canceller (IC) and the second interference canceller is a linear/nonlinear interference canceller (IC).