Offset Modulation Precoding for MIMO BER and Complexity Trade-off
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Solution Overview
Problem
Current precoding methods in MIMO technologies face a trade-off between Bit Error Ratio (BER) performance and computational complexity, with linear precoding offering low complexity but high BER, and nonlinear precoding reducing BER but at the cost of significantly increased complexity, especially for methods like Dirty Paper Coding (DPC).
Innovation Solution
A precoding method that performs offset modulation on transmitting signals and calculates a precoding matrix based on the mean square error between the transmitting and decision signals, using a combination of MMSE and ZF algorithms to minimize complexity while reducing BER, by obtaining the precoding matrix through channel estimation and noise variance calculation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If linear precoding is used, then computational complexity is low, but BER performance is high
Solution Approach 1:
The patent applies preliminary action by performing offset modulation on the transmitting signal before precoding. This preprocessing step modifies the signal characteristics to be more suitable for linear precoding, enabling the system to achieve better BER performance while maintaining low computational complexity. The offset modulation prepares the signal in advance so that subsequent linear precoding operations can effectively reduce interference without requiring complex nonlinear processing.
2Reliability
If nonlinear precoding is used, then BER performance is reduced, but computational complexity is significantly increased
Solution Approach 1:
The patent applies parameter changes by modifying the signal representation through offset modulation, which transforms the transmitting signal into a form where the real part contains the essential information. This parameter transformation allows the system to use simpler linear precoding instead of complex nonlinear precoding, achieving a favorable balance between BER performance and computational complexity by changing the signal domain rather than increasing processing complexity.
3Reliability
If DPC is used, then BER performance is improved, but computational complexity increases exponentially
Solution Approach 1:
The patent applies this principle by replacing the computationally expensive DPC algorithm with a more economical approach. Through offset modulation and linear precoding, the system achieves acceptable BER performance without the exponential computational complexity of DPC. The solution uses simpler, more efficient processing that is computationally affordable while still providing significant performance improvement over conventional linear precoding.
Data Source
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AI summary
A precoding method, a precoding apparatus, a Frequency Domain Equalization (FDE) method, and an FDE apparatus are provided in the embodiments of the present invention. The precoding method includes: performing offset modulation for a transmitting signal vector; calculating a precoding matrix according to the offset-modulated transmitting signal vector and a receiver decision signal vector, where the precoding matrix is used for performing precoding for the transmitting signal vector; and performing precoding for the transmitting signal vector according to the precoding matrix. Linear precoding is performed by using the offset-modulated signal on the transmitter, and therefore, the interference caused by multiple antennas and multipath propagation is reduced, the system BER is reduced, and the complexity of implementation is low.