Priority-Based Space-Time Coding for Wireless Data Streams
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Solution Overview
Problem
Current space-time coding methods for multiple data streams in wireless communications do not efficiently allow high-priority data streams to be decoded without a significant complexity penalty from the presence of low-priority streams, especially in systems with multiple transmit antennas.
Innovation Solution
The method involves establishing priorities for data streams, determining desired signal quality based on these priorities, and selecting appropriate space-time codes and weightings to modulate and combine data streams, ensuring high-priority streams can be decoded with lower signal-to-interference-plus-noise ratios than low-priority streams without increasing decoding complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If standard space-time codes are used for multiple data streams, then data transmission reliability is improved, but decoding complexity increases significantly for high-priority streams due to the presence of low-priority streams
Solution Approach 1:
The patent segments the multiple data streams into priority groups (high-priority and low-priority streams) and applies different space-time coding strategies to each group. High-priority streams use orthogonal space-time codes that can be decoded independently, while low-priority streams use non-orthogonal codes that do not interfere with high-priority stream decoding, thus reducing overall decoding complexity while maintaining reliability
Solution Approach 2:
The patent applies different coding qualities to different parts of the transmission system by using orthogonal codes for high-priority streams (ensuring simple, reliable decoding) and non-orthogonal codes for low-priority streams (optimizing spectral efficiency). This local differentiation allows each stream type to be optimized for its specific requirements without compromising the other
2Device complexity
If orthogonal space-time codes are used for all data streams, then decoding complexity is reduced, but spectral efficiency decreases due to increased resource allocation for high-priority streams
Solution Approach 1:
The patent applies different coding schemes to different data streams based on their priority and requirements. High-priority streams use orthogonal codes for simple decoding, while low-priority streams use non-orthogonal codes that achieve better spectral efficiency. This selective approach optimizes overall system performance without sacrificing decoding simplicity for critical streams
Solution Approach 2:
The patent creates a composite coding structure by combining orthogonal and non-orthogonal space-time codes within the same transmission system. This composite approach allows the system to leverage the advantages of both coding types: the simplicity and reliability of orthogonal codes for high-priority streams, and the spectral efficiency of non-orthogonal codes for low-priority streams
3Productivity
If non-orthogonal space-time codes are used to improve spectral efficiency, then data transmission capacity increases, but interference between streams increases making decoding more difficult
Solution Approach 1:
The patent segments the codebook into orthogonal and non-orthogonal code sets, assigning orthogonal codes to high-priority streams to eliminate interference, and non-orthogonal codes to low-priority streams where some interference is acceptable. This segmentation allows the system to achieve high spectral efficiency overall while protecting critical streams from interference
Solution Approach 2:
The patent converts the potential harm of inter-stream interference into a benefit by using non-orthogonal codes for low-priority streams that can tolerate some interference, while using orthogonal codes for high-priority streams that are protected from interference. The interference that would normally be harmful is instead managed strategically to optimize overall system performance
Data Source
AI summary
Embodiments for space-time coding are disclosed. One method includes establishing a priority for each of a plurality of data streams. A number of data bits for each of the plurality of data streams are allocated. A desired signal quality for each of the plurality of data streams is determined based on the corresponding priority. Each of the plurality of data streams are modulated according to the allocated number of data bits of each of the plurality of data streams. A space-time code is selected for each of the plurality of data streams based at least partially on the desired signal quality for each of the plurality of data streams, wherein at least one of the space-time codes is at least one of a vector or a matrix. Each of the modulated data streams are space-time coded with the selected space-time code. The space-time coded modulated data streams are summed, and transmitted.