Multi-User Detector Interference Mitigation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In CDMA communication systems, multi-user detectors operate sub-optimally under high interference conditions, leading to underutilization of capacity and inadequate interference suppression, as they are typically dimensioned for low interference scenarios.
Innovation Solution
The spare capacity of the multi-user detector is utilized to include signals from neighboring cells in the detection process, allowing for improved interference mitigation and increased flexibility by reallocating resources to accommodate intercell interference, thereby enhancing overall system performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the multi-user detector is dimensioned for the low interference case, then the detection performance is improved under low interference conditions, but the detector capacity is under utilized under high interference conditions
Solution Approach 1:
The multi-user detector dynamically adapts its processing capacity allocation based on interference conditions. The detector switches between processing only intracell codes and processing both intracell and intercell codes, optimizing performance for the current interference environment rather than being fixed for low interference conditions
2Object-affected harmful factors
If the number of codes is reduced under high interference conditions, then the interference suppression is improved, but the multi-user detector capacity is under utilized
Solution Approach 1:
The invention converts the harmful intercell interference into a processable signal by including neighbour cell codes in the multi-user detection. The detector uses its spare capacity to process these previously harmful interference signals, transforming them into useful information that can be suppressed or utilized
3Object-affected harmful factors
If the multi-user detector includes signals from neighbour cells, then the intercell interference mitigation is improved, but the detector complexity is increased
Solution Approach 1:
The multi-user detector is designed to perform multiple functions: it can process only intracell codes when interference is low, or process both intracell and intercell codes when interference is high. This multi-functionality allows the same detector structure to handle different interference scenarios without requiring separate specialized detectors
Data Source
AI summary
A multi-user detector (200) and method (300) for use in a cellular CDMA system (100) based on: estimating (210) spare code resource available in a first cell of the system; selecting (220) at least a second cell neighbouring the first cell; selecting (230) from codes associated with the second cell at least one additional code; and performing (240) multi-user detection processing in the first cell with the at least one additional code. On the downlink, codes from other users in the same cell may be treated with the same level of priority as those of users from neighbour cells, codes allocated to the UE having the highest priority; on the uplink, codes of all users in the same cell may have the same priority which is higher than that of neighbour cell users. This provides the advantage(s) that multi-user detector capacity arising from operating under high interference conditions is employed to accommodate users from neighbour cells, with the result that both intracell and intercell interference may be mitigated.