Interference Alignment Pre-coding for Cellular Spectrum Efficiency
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Solution Overview
Problem
In wireless mobile cellular networks, co-channel interference between neighboring cells at the same frequency range degrades communication quality and reduces frequency spectrum utilization efficiency, as existing methods either reduce interference but waste resources or enhance resources but fail to effectively manage interference.
Innovation Solution
A pre-coding and pre-decoding method using an interference alignment scheme, which computes antenna mapping, multi-cell pre-coding, and decoding matrices based on downlink channel state information to separate desired and interference signal spaces, allowing for efficient interference suppression and resource allocation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If frequency-division multiplexing is adopted to avoid interference between neighboring cells, then co-channel interference is suppressed, but frequency spectrum utilization efficiency is reduced
Solution Approach 1:
The patent segments the signal space into two distinct subspaces: a desired signal subspace and an interference signal subspace. By computing antenna mapping matrices and pre-coding matrices that project transmitted signals into these separated subspaces, the system achieves interference suppression without requiring frequency-division multiplexing, thereby maintaining high frequency spectrum utilization efficiency while eliminating co-channel interference between neighboring cells
Solution Approach 2:
The patent transitions from frequency-domain separation (traditional FDM) to spatial-domain separation by introducing antenna mapping in the spatial dimension. Through multi-antenna transmission and reception with carefully designed mapping matrices, the system separates desired and interference signals in the spatial domain, allowing simultaneous use of the same frequency band while avoiding interference
2Reliability
If co-channel interference management method is used to improve communication quality, then communication quality is improved, but frequency spectrum utilization efficiency is reduced
Solution Approach 1:
The patent segments the signal space into two distinct subspaces: a desired signal subspace and an interference signal subspace. By computing antenna mapping matrices and pre-coding matrices that project transmitted signals into these separated subspaces, the system achieves interference suppression without requiring frequency-division multiplexing, thereby maintaining high frequency spectrum utilization efficiency while eliminating co-channel interference between neighboring cells
Solution Approach 2:
The patent changes the spatial parameters of signal transmission by introducing antenna mapping matrices that transform the transmission from conventional single-antenna or simple MIMO to a structured spatial multiplexing system. This parameter change in the spatial domain enables simultaneous achievement of high communication quality and high frequency spectrum utilization efficiency
Data Source
AI summary
The transmitter and a mobile terminal based on interference alignment use pre-coding and pre-decoding methods. An antenna mapping matrix is computed according to a downlink channel state information, wherein the antenna mapping matrix is used for antenna mapping for the current transmitter to perform interference alignment. A multi-cell pre-coding matrix according to the downlink channel state information and the antenna mapping matrix; a single cell multi-user pre-coding matrix and pre-coding user data using the single cell multi-user pre-coding matrix and the multi-cell pre-decoding matrix and performing an antenna mapping using the antenna mapping matrix are computed. A system which cannot use the interference alignment method directly may be transformed to use the interference alignment method directly. In addition, the interference suppression between cells and the interference management inside cells are two separate processes, in which different linear pre-coding and decoding methods may be used.