Transmitter Precoding Weights for STTD Spatial Multiplexing Interference
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Solution Overview
Problem
In radio frequency communications systems, transmitted signals from multiple antennas can interfere with each other, degrading the performance of the receiver during equalization, particularly in systems using Space Time Transmit Diversity (STTD) and spatial-multiplexing techniques.
Innovation Solution
The use of precoding weights and orthogonal signal spaces for transmitted signals from multiple antennas, allowing the signals to be transmitted over the same physical resource without interference, by employing a combination of STTD encoding and spatial-multiplexing, ensures that the signals do not interfere with each other during equalization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Space Time Transmit Diversity (STTD) encoding is used to transmit signals from multiple antennas, then diversity benefits are improved, but signal interference between antennas increases, degrading receiver performance
Solution Approach 1:
The patent applies parameter changes by introducing precoding weights as complex parameters that modify the transmitted signals. These weights are specifically designed to orthogonalize the signal spaces of multiple antennas, transforming the interference problem into a solvable mathematical problem through parameter optimization in the signal processing domain
2Productivity
If spatial-multiplexing is used to transmit signals over the same physical resource, then data transmission capacity is improved, but interference between signals increases
Solution Approach 1:
The patent introduces precoding weights as an intermediary element between the data streams and the physical transmission medium. These weights act as a mediator that transforms the signal space of multiple data streams into orthogonal domains, allowing simultaneous transmission without mutual interference while maintaining full data transmission capacity
3Measurement precision
If equalization is performed to compensate for channel effects, then signal quality is improved, but interference from multiple data streams exacerbates the problem
Solution Approach 1:
The patent applies preliminary action by performing signal orthogonalization at the transmitter before the signals enter the channel. The precoding weights are computed in advance to ensure that the signal spaces remain orthogonal throughout transmission, preventing interference from being introduced during the equalization process at the receiver
Data Source
AI summary
A method and transmitter are disclosed. The method includes encoding data according to a space time transmit diversity scheme and spatial-multiplexing the encoded data. The transmitter includes first and second units. The first unit is configured to encode data according to a space time transmit diversity scheme and the second unit is configured to spatial-multiplex encoded data. The transmitter is configured to operate in an operating mode in which data is processed by the first unit and the second unit.