Modified THP Precoding Arbitrary Power Allocation
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Solution Overview
Problem
Current nonlinear precoding techniques for downlink multi-user MIMO channels, such as Tomlinson-Harashima Precoding (THP), are limited by fixed power allocation and high computational complexity, which restricts their ability to optimize user power allocation and maximize weighted sum-rate, leading to performance degradation.
Innovation Solution
A modified THP algorithm that allows the use of an arbitrary effective linear precoder, enabling flexible user power optimization and sum-rate maximization, with a closed-form power allocation formula for high SNR approximation, simplifying the calculation of transmit power normalization factors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If fixed power allocation is used in nonlinear precoding techniques, then implementation complexity is reduced, but weighted sum-rate optimization capability deteriorates
Solution Approach 1:
The patent implements dynamic power allocation by introducing a power allocation matrix that can be adjusted based on channel conditions and user requirements. The power allocation is no longer fixed but adapts to maximize weighted sum-rate while maintaining reasonable computational complexity through iterative optimization algorithms.
Solution Approach 2:
The patent changes the power allocation parameter from a fixed value to a dynamically adjustable parameter. By introducing power allocation coefficients that can be optimized independently of the precoding matrix, the system achieves better weighted sum-rate performance without proportionally increasing implementation complexity.
2Adaptability or versatility
If arbitrary precoder is used, then performance optimization freedom is improved, but computational complexity increases
Solution Approach 1:
The patent segments the precoding process into distinct components: the precoding matrix, the power allocation matrix, and the feedforward filter. This segmentation allows each component to be optimized independently, providing performance optimization freedom while managing computational complexity through modular processing.
Solution Approach 2:
The patent introduces dynamic power allocation that adapts to different users and channel conditions. The power allocation matrix can be adjusted independently of the precoding matrix, providing flexibility in performance optimization while maintaining manageable computational complexity through separate optimization of each component.
3Device complexity
If standard THP algorithm is used, then computational complexity is reduced, but total cell throughput is limited
Solution Approach 1:
The patent modifies the standard THP algorithm by introducing power allocation parameters that can be optimized to maximize total cell throughput. The power allocation matrix allows different power levels to be assigned to different users and layers, improving overall system throughput while maintaining the computational efficiency of the THP structure.
Solution Approach 2:
The patent enhances the standard THP algorithm by making power allocation dynamic rather than fixed. The power allocation matrix can be adjusted based on channel conditions and user requirements, enabling the system to achieve higher total cell throughput while maintaining reasonable computational complexity through iterative optimization.
Data Source
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AI summary
Method and apparatus are provided for transmission of data. A precoder is selected, and a feedforward filter is derived in accordance with the precoder. In some embodiments, the precoder is an arbitrary effective precoder. Data prepared using the precoder and the feedforward filter can then be transmitted.