Uplink Resource Allocation in OFDMA Systems
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Solution Overview
Problem
Current Broadband Wireless Access (BWA) communication systems, particularly OFDMA-TDD mobile communication systems, lack an efficient method for uplink resource allocation that balances maximizing radio channel throughput, minimizing transmission delay, reducing interference, and optimizing power consumption while maintaining stable link performance.
Innovation Solution
An apparatus and method that utilize power headrooms and downlink Signal-to-Interference and Noise Ratios (SINRs) to calculate a scheduling metric for each Mobile Station (MS), select MSs with high priority, determine a Modulation Order Product Coding Rate (MPR) and subchannel number combination, and allocate resources to reduce power consumption and interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If uplink resources are allocated to maximize radio channel throughput, then cell throughput is improved, but power consumption and interference with neighbor cells increase
Solution Approach 1:
The patent applies local quality by determining MS location within the cell (center vs. edge) and allocating different MCS levels and subchannel numbers based on location. Edge MSs receive lower MCS levels and fewer subchannels to reduce interference and power consumption, while center MSs can utilize higher MCS levels for maximum throughput. This location-based differential allocation resolves the contradiction between maximizing throughput and minimizing power/interference.
Solution Approach 2:
The patent implements dynamic resource allocation by continuously monitoring MS location, power headroom, and channel conditions to adaptively adjust MCS levels and subchannel numbers. The base station dynamically recalculates scheduling metrics and reallocates resources frame-by-frame, allowing the system to optimize throughput while controlling power consumption and interference based on current system state.
2Productivity
If uplink resources are allocated to maximize radio channel throughput, then cell throughput is improved, but interference with neighbor cells increases
Solution Approach 1:
The patent applies local quality by determining MS location within the cell (center vs. edge) and allocating different MCS levels and subchannel numbers based on location. Edge MSs receive lower MCS levels and fewer subchannels to reduce interference with neighbor cells, while center MSs can utilize higher MCS levels for maximum throughput. This location-based differential allocation resolves the contradiction between maximizing throughput and minimizing interference.
Solution Approach 2:
The patent converts the potentially harmful effect of uplink transmissions into benefit by using power headroom information to optimize resource allocation. MSs with limited power headroom (likely at cell edge) are allocated resources that ensure their transmissions do not cause excessive interference to neighbor cells, while still maintaining acceptable throughput. The power constraints are transformed from limitations into a mechanism for interference control.
3Loss of energy
If resource allocation is optimized for power consumption reduction, then power consumption is reduced, but radio channel throughput decreases
Solution Approach 1:
The patent implements dynamic resource allocation by continuously monitoring MS location, power headroom, and channel conditions to adaptively adjust MCS levels and subchannel numbers. The base station dynamically recalculates scheduling metrics and reallocates resources frame-by-frame, allowing the system to optimize throughput while controlling power consumption based on current system state. This dynamic approach resolves the contradiction by finding the optimal balance point that varies with conditions.
Solution Approach 2:
The patent changes key parameters (MCS level and subchannel number) based on MS location and power headroom conditions. By adjusting these parameters dynamically, the system optimizes the trade-off between power consumption and throughput. Center MSs with high power headroom use higher MCS levels for maximum throughput, while edge MSs with limited power headroom use lower MCS levels to conserve power, resolving the contradiction through parameter adaptation.
4Ease of operation
If uplink resources are allocated without considering MS location, then allocation simplicity is maintained, but fair distribution and throughput optimization are reduced
Solution Approach 1:
The patent applies preliminary action by determining MS location within the cell before performing resource allocation. The base station calculates scheduling metrics based on MS location, power headroom, and channel conditions in advance of the actual resource assignment. This preliminary classification of MSs by location enables the subsequent allocation process to be both simple (using pre-determined categories) and optimized (using location-appropriate MCS levels and subchannel numbers).
Data Source
AI summary
The present invention is provided a method for allocating uplink resources in a communication system. The method includes calculating a scheduling metric for each Mobile Station (MS), selecting an MS with a high priority according to the scheduling metric, determining a Modulation order Product coding Rate (MPR) and a number of subchannels for the selected MS, and allocating the determined MPR and the determined number of subchannels to the selected MS and updating the scheduling metric for the each MS.