Multi-Code-Set Channel Estimation for CDMA Interference Cancellation
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Solution Overview
Problem
The existing uni-code-set channel estimation method in time-slot CDMA systems faces performance limitations due to interference from signals of neighboring cells with the same frequency, leading to suboptimal channel estimation and reception performance, especially in multi-antenna systems.
Innovation Solution
A multi-code-set channel estimation method that iteratively reproduces and cancels interference signals from other code-sets, improving channel estimation performance and reducing computational complexity by extracting and processing a maximum interference tap.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the uni-code-set channel estimation method is used, then the calculation cost is reduced, but the channel estimation accuracy deteriorates due to interference from neighboring cells with the same frequency
Solution Approach 1:
The patent segments the channel estimation process into multiple code-sets, where each code-set handles specific interfering signals from neighboring cells. By dividing the estimation task across multiple code-sets and selectively combining results, the system reduces interference impact while maintaining computational efficiency.
Solution Approach 2:
The patent combines channel estimation results from multiple code-sets to form a composite estimation that cancels out interference from neighboring cells. This composite approach leverages the complementary nature of different code-sets to achieve higher accuracy than any single code-set alone.
2Measurement precision
If the multi-code-set joint channel estimation is implemented to improve accuracy, then the channel estimation performance is enhanced, but the computational complexity increases
Solution Approach 1:
The patent applies partial action by selectively combining results from only those code-sets that are most effective at canceling specific interference sources. Rather than processing all possible code-sets equally, the method identifies and processes the most relevant subsets, reducing computational complexity while maintaining accuracy benefits.
Solution Approach 2:
The patent segments the multi-code-set estimation into independent processing stages, where each code-set is processed separately and then combined. This segmentation allows for efficient parallel processing and reduces the overall computational burden compared to a monolithic approach.
3Measurement precision
If the interference cancellation is performed for all code-sets, then the channel estimation accuracy is maximized, but the implementation cost increases
Solution Approach 1:
The patent performs interference cancellation only for the most significant interfering code-sets rather than all possible code-sets. By identifying and targeting only the dominant interference sources, the system achieves most of the accuracy improvement with significantly reduced implementation complexity and cost.
Solution Approach 2:
The patent applies different processing quality levels to different code-sets based on their interference characteristics. High-priority code-sets with significant interference receive full cancellation processing, while lower-priority code-sets receive simplified or no processing, optimizing the trade-off between accuracy and implementation cost.
Data Source
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AI summary
A multiple code-set channel estimation method in time-slot CDMA system, includes the step of: A, performing a single code-set channel estimation for each code-set signal, respectively, to obtain an channel estimation result; B, extracting the maximum interference tap from said result of channel estimation; C, resuming the interference component caused by the response of the maximum interfere tap to each code-set signal, and obtaining the channel estimation result of clean signal of each code-set; E, deciding whether the number of interaction are reached, if so, outputting the channel estimation result of each single code-set, otherwise, making the channel estimation result of clean signal of each code-set as the channel estimation result of the code-set to be processed at nest step, and returning to the step B. By use of the present invention, the multiple code-set union channel estimation can be implemented simply and effectively.