Per Stream Rate Control for OFDM-MIMO Throughput Optimization
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Solution Overview
Problem
Current wireless communication systems, particularly OFDM-MIMO systems, face challenges in efficiently using available resources for data transmission, as there is no established method for optimizing system efficiency similar to Per Stream Rate Control (PSRC) schemes used in CDMA systems.
Innovation Solution
Adaptive modulation and coding techniques, combined with sub-carrier allocation and power control, are applied in OFDM-MIMO systems to split user-data streams into sub-streams, select optimal modulation schemes and coding rates based on channel conditions, and allocate sub-carriers to transmit antennas for improved throughput and signal quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If OFDM-MIMO systems transmit multiple data streams simultaneously, then data throughput increases, but system resource efficiency deteriorates due to lack of optimization mechanisms
Solution Approach 1:
The patent segments the data transmission process into multiple independent sub-streams, each processed separately through adaptive modulation, coding, and power control. This allows individual optimization of each sub-stream's resource allocation while maintaining overall high throughput through parallel transmission across multiple antennas and sub-carriers.
Solution Approach 2:
The patent implements dynamic adaptation of transmission parameters including modulation schemes, coding rates, and transmit power levels based on real-time channel conditions. This dynamic optimization ensures efficient resource utilization by adjusting parameters to match current channel quality, preventing waste of transmission resources while maintaining maximum throughput.
2Productivity
If adaptive modulation and coding are applied to each sub-stream, then system efficiency improves, but computational complexity increases
Solution Approach 1:
The patent applies different modulation schemes, coding rates, and power levels to different sub-streams based on their specific channel conditions. Each sub-stream receives locally optimized parameters tailored to its quality of service requirements and channel state, achieving high overall efficiency without requiring uniform complex processing across all streams.
Solution Approach 2:
The patent changes transmission parameters (modulation order, coding rate, power level) dynamically based on channel conditions and quality of service requirements. This parameter adaptation allows the system to optimize performance by selecting from discrete parameter sets, reducing computational complexity compared to continuous optimization while maintaining high efficiency.
3Productivity
If joint control of adaptive modulation, coding, and power control is implemented, then throughput and signal quality are optimized, but control complexity increases
Solution Approach 1:
The patent merges the control of adaptive modulation, coding, and power control into a unified joint optimization framework. By coordinating these three functions together rather than independently, the system achieves optimal throughput and signal quality through synergistic parameter selection, while the modular structure of the joint controller manages complexity through systematic integration.
Solution Approach 2:
The patent creates a multi-functional control mechanism that simultaneously manages modulation scheme selection, coding rate determination, and power level adjustment. This universal controller handles multiple functions through a coordinated decision-making process, optimizing overall system performance while avoiding the need for separate independent control systems for each parameter.
Data Source
AI summary
A transmitter splits a user-data stream into a plurality of sub-streams. The transmitter then adaptively selects a modulation scheme and coding rate for each of the sub-streams based on current channel conditions. Next, a plurality of sub-carriers are modulated and encoded with the sub-stream data according to the selected modulation schemes and coding rates. The modulated sub-carriers are each allocated to one or more transmit antennas for transmission. Prior to transmission, a transmission power for each of the sub-carriers is adjusted based on the channel conditions. The adaptive modulation and coding function, the sub-carrier allocation function, and the power control function are jointly controlled to optimize throughput, signal quality, and system efficiency.