Wireless Communication Device Orthogonal Carrier Mapping
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Solution Overview
Problem
Frequency-shift keying (FSK) communication systems experience deteriorated transmission quality due to intentional signal distortion when applying existing transmission diversity techniques.
Innovation Solution
A wireless communication device employing a mapping unit that allocates orthogonal carrier waves to multiple transmitting antennas, ensuring orthogonality of transmission signals and maintaining power efficiency by performing a spatial/frequency mapping process before modulation, thereby avoiding phase discontinuity and enhancing resistance to channel variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cyclic delay diversity is applied to FSK communication system, then transmission diversity is obtained, but transmission quality is deteriorated due to intentional signal distortion
Solution Approach 1:
The invention divides the FSK signal into multiple parallel branches, each corresponding to a different antenna. Each branch applies a distinct cyclic delay specific to that antenna while maintaining the original FSK modulation characteristics. This segmentation allows diversity gain without distorting the signal envelope, resolving the contradiction between obtaining diversity and maintaining transmission quality.
Solution Approach 2:
The invention applies cyclic delays to the FSK signals before transmission through different antennas, as a preliminary action. By pre-processing the signals with antenna-specific delays while preserving their constant envelope property, the system achieves spatial diversity without introducing signal distortion that would degrade transmission quality.
2Use of energy by moving object
If FSK modulation is used, then power efficiency is improved, but transmission quality deteriorates without diversity technique
Solution Approach 1:
The invention merges FSK modulation with cyclic delay diversity by combining frequency modulation with time-domain delays in a unified transmission framework. Each antenna transmits FSK-modulated signals with unique cyclic delays, merging the power efficiency benefits of FSK with the reliability improvements of diversity techniques.
Solution Approach 2:
The invention adds the time-delay dimension to the frequency-modulated FSK signals. By introducing cyclic delays as an additional degree of freedom alongside frequency modulation, the system achieves diversity gain in the time domain while maintaining the power efficiency advantages of FSK in the frequency domain.
Data Source
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AI summary
A wireless communication device includes: a plurality of transmitting antennas (13); a modulation unit (12) that generates a transmission signal transmitted from each of the transmitting antennas (13) by performing frequency-shift keying on a carrier wave on the basis of transmission data; and a mapping unit (11) that is provided in a preceding stage of the modulation unit (12) and allocates carrier waves different from each other to the plurality of transmitting antennas (13) such that a plurality of transmission signals each transmitted from one of the plurality of transmitting antennas (13) are orthogonal to each other.