Wireless Transmitter I-Q Component Conversion for Multiplexing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional radio transmission methods face challenges in maintaining orthogonality among code-multiplexed data streams, leading to suboptimal reception performance when different data streams require different spreading domains for improved frequency or time domain reception.
Innovation Solution
A radio communication apparatus and method that divide modulated symbols into in-phase and quadrature components, convert these components, and perform multi-code multiplexing to combine signals in a way that allows each data stream to be spread in its optimal domain, maintaining orthogonality and minimizing the required Eb/N0 for improved reception.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If all data streams use the same spreading domain to maintain orthogonality, then orthogonality is maintained, but reception performance deteriorates for data streams that would benefit from a different spreading domain
Solution Approach 1:
The patent segments the in-phase and quadrature components of modulated symbols into separate processing paths. By dividing the signal components and applying different spreading domains to different segments (I-component vs Q-component), the system allows each data stream to be spread in its optimal domain while maintaining orthogonality through the segmented structure.
Solution Approach 2:
The patent introduces a new dimension of differentiation by separating processing into in-phase and quadrature components. This dimensional separation allows the system to apply frequency domain spreading to one component and time domain spreading to another component, enabling adaptability across different spreading domains without compromising orthogonality.
2Reliability
If data streams are code-multiplexed with different spreading domains, then reception performance improves for individual streams, but orthogonality cannot be maintained
Solution Approach 1:
The patent segments the signal into in-phase and quadrature components, assigning different spreading domains to each segment. This segmentation allows data streams to use different spreading domains (frequency or time domain) while maintaining orthogonality through the segmented component structure, resolving the contradiction between performance improvement and orthogonality maintenance.
Solution Approach 2:
The patent applies local quality by allowing different spreading domains to be applied to different local components (I-component versus Q-component) of the modulated symbols. Each component can be optimally spread according to its specific requirements while the overall structure maintains orthogonality through the localized differentiation.
3Ease of manufacture
If frequency domain spreading is used for all data streams, then implementation is simplified, but reception performance deteriorates for data streams that would benefit from time domain spreading
Solution Approach 1:
The patent introduces dynamics by making the spreading domain selection adaptive rather than fixed. The system can dynamically assign frequency domain spreading or time domain spreading to different data streams based on their specific requirements, allowing the implementation to adapt to performance needs while maintaining reasonable complexity through the segmented processing approach.
Data Source
AI summary
A wireless transmitting apparatus capable of improving the reception characteristic at a data stream receiving end. In this apparatus, I/Q separating parts (110, 112) each separate first data modulated symbols included in any of a plurality of data streams, which are to be multiplexed, into first in-phase components and first orthogonal components, while separating second data modulated symbols included in the other ones of the plurality of data streams into second in-phase components and second orthogonal components. An I/Q converting part (114) converts the first in-phase components to third orthogonal components, while converting the second orthogonal components to fourth in-phase components. A multi-code multiplexing part multi-code multiplexes the first and third orthogonal components to provide a first multiplexed signal, while multi-code multiplexing the second and fourth in-phase components to provide a second multiplexed signal. An I/Q combining part (124) combines the first and second multiplexed signals to provide a combined signal.