MIMO Stream Prioritization for Higher-Capacity Wireless Links
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Solution Overview
Problem
Current MIMO communication systems face limitations in increasing transmission capacity without broadening frequency ranges, increasing modulation multivalued numbers, or enlarging circuit sizes, due to constraints on RF circuit capabilities and costs.
Innovation Solution
The system employs a MIMO transmission algorithm that divides transmission streams into bit-series groups with assigned priority levels, subjecting them to encoding, modulation, weighting, and synthesis for spatial multiplexing, allowing for increased transmission capacity without frequency range expansion or circuit size increase, using methods like turbo and LDPC encoding for improved decoding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the number of reception antennas is increased to increase the number of streams subjected to spatial multiplexing, then transmission capacity is improved, but device complexity and cost increase
Solution Approach 1:
The patent changes the parameter of modulation multivalued number from conventional values (up to 64 QAM) to higher values (256 QAM or more), thereby increasing transmission capacity without adding antennas or circuit complexity. This parameter change in modulation depth allows the system to achieve higher data rates within existing hardware constraints.
2Productivity
If the modulation multivalued number is increased to increase transmission capacity, then productivity is improved, but reliability deteriorates due to RF circuit imperfections
Solution Approach 1:
The patent applies different priority levels to different bit-series groups, where high-priority bits use more robust modulation and coding schemes while low-priority bits can use higher-order modulation. This local differentiation in quality allows the system to achieve high overall transmission capacity while maintaining reliability for critical data portions, even with RF imperfections.
3Productivity
If the range of frequencies is broadened to increase transmission capacity, then productivity is improved, but adaptability deteriorates due to frequency allocation constraints
Solution Approach 1:
Instead of expanding the frequency dimension, the patent transitions to the modulation dimension by increasing the multivalued number. This dimensional shift allows capacity expansion from using more spectrum to using more states per signal, thereby achieving higher transmission capacity within the same frequency allocation constraints.
Data Source
AI summary
A wireless communication system includes a transmitting device and a receiving device each including a plurality of antennas. A plurality of streams are subjected to spatial multiplexing and are transmitted in a downlink in which packets are transmitted from the transmitting device to the receiving device. In the transmitting device, each of the plurality of transmission streams is divided into a plurality of bit-series groups having decoding characteristics to which priority levels are assigned, the bit-series groups are subjected to encoding processes and modulating processes in accordance with the priority levels and further subjected to weighting and synthesizing, and each of the plurality of transmission streams in which a plurality of bit series items are synthesized with one another is spatially multiplexed and transmitted.