MIMO Bit-Stream Prioritization for Capacity Under RF Constraints
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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 expanding 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 antennas is increased to increase transmission capacity, then transmission capacity is improved, but device complexity and cost increase
Solution Approach 1:
The invention segments the transmission process by dividing transmission streams into bit-series groups with different priority levels. High-priority groups use robust modulation (e.g., BPSK, QPSK) while low-priority groups use higher-order modulation (e.g., 16-QAM, 64-QAM). This segmentation allows the system to achieve higher transmission capacity without increasing the number of antennas, as each antenna transmits efficiently optimized streams.
Solution Approach 2:
The invention changes modulation parameters dynamically based on priority levels. Different bit-series groups are assigned different modulation schemes (BPSK, QPSK, 16-QAM, 64-QAM, etc.), allowing the system to optimize transmission capacity within the existing antenna configuration. This parameter change approach avoids the need for additional antennas while achieving higher data rates.
2Productivity
If frequency range is broadened to increase transmission capacity, then transmission capacity is improved, but frequency allocation constraints prevent usage
Solution Approach 1:
Instead of broadening frequency range, the invention changes other transmission parameters - specifically modulation order and coding rate - to increase transmission capacity. By using priority-based modulation where high-priority data uses robust schemes and low-priority data uses higher-order schemes, the system achieves higher capacity within the allocated frequency band without facing frequency allocation constraints.
3Productivity
If modulation multivalued number is increased to increase transmission capacity, then transmission capacity is improved, but EVM requirements cannot be met due to RF circuit imperfections
Solution Approach 1:
The invention segments data into priority-based bit-series groups, allowing different modulation schemes to be applied to different groups. High-priority groups use robust modulation (BPSK, QPSK) that meets EVM requirements even with RF imperfections, while low-priority groups use higher-order modulation (16-QAM, 64-QAM) that provides higher capacity when channel conditions permit. This segmentation resolves the contradiction by ensuring reliability for critical data while achieving higher overall capacity.
Solution Approach 2:
Different parts of the transmission (different bit-series groups) are assigned different modulation qualities based on their priority. High-priority data receives high-quality robust modulation that guarantees EVM compliance, while low-priority data receives lower-quality higher-order modulation that maximizes capacity. This local quality differentiation allows the system to achieve high transmission capacity without compromising the reliability of critical transmissions.
4Productivity
If priority-based encoding and modulation is applied to bit-series groups, then transmission capacity and frequency efficiency are improved, but decoding complexity increases
Solution Approach 1:
The transmitter performs preliminary actions by assigning priority levels and selecting appropriate modulation schemes for each bit-series group before transmission. This preliminary organization of data into priority-based groups with predetermined modulation schemes simplifies the receiver's decoding task, as it can process groups in priority order using pre-determined demodulation strategies, reducing overall decoding complexity despite the multiple modulation types.
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.