OFDM Frame Scheduling Using Two-Dimensional Resource Allocation
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Solution Overview
Problem
Existing schedulers are not suitable for OFDMA systems, which require two-dimensional resource management for multiple users experiencing different channel conditions at different times and frequencies, leading to inefficiencies in resource allocation and transmission.
Innovation Solution
A method and system for scheduling OFDM frames that assign packets multiple scheduling metrics, produce orderings to select packets for transmission, and construct frames with rectangular time-frequency bursts, using multiple antennas for efficient resource allocation and retransmissions, while considering channel conditions and power save modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional sequential schedulers are used for resource allocation, then the scheduling process is simple, but they cannot handle two-dimensional resource management for multiple users with different channel conditions
Solution Approach 1:
The patent transitions from one-dimensional sequential scheduling to two-dimensional time-frequency resource allocation. Resources are organized in a time-frequency grid where multiple users can be scheduled simultaneously across different frequency subcarriers and time slots, enabling the system to handle multiple users with different channel conditions effectively.
Solution Approach 2:
The available frequency spectrum is divided into multiple orthogonal subcarriers, and time is divided into discrete slots. This segmentation creates a two-dimensional resource grid that can be independently allocated to different users based on their channel conditions, achieving both versatility and manageable complexity.
2Productivity
If multiple scheduling metrics are assigned to each packet and complex ordering is performed, then resource allocation efficiency is improved, but the computational complexity increases
Solution Approach 1:
Packets are pre-categorized into different queues based on their QoS requirements and channel conditions before scheduling. This preliminary classification allows the scheduler to efficiently select packets from appropriate queues using simple metrics like deadline and priority, rather than computing complex orderings for all packets, thus improving efficiency while controlling complexity.
Solution Approach 2:
The patent uses multiple scheduling metrics (deadline, priority, channel quality) to dynamically adjust packet ordering based on current system conditions. By changing the weighting or selection of these parameters adaptively, the system optimizes resource allocation efficiency without requiring overly complex computational algorithms.
3Productivity
If rectangular time-frequency bursts are used for packet transmission, then resource allocation is optimized, but flexibility in handling different packet sizes is reduced
Solution Approach 1:
Large packets are segmented into smaller units that can be allocated to rectangular time-frequency bursts of standardized sizes. This segmentation allows efficient packing of packets into the two-dimensional resource grid while maintaining the ability to handle variable packet sizes through systematic division and recombination of data units.
Data Source
AI summary
System and methods for scheduling OFDM frames are provided. Each packet is assigned to a frame bucket, this amounting to a temporary decision of when to transmit the packet. Each packet is marked with one or more metrics. The metrics are used to sort packets and make scheduling decisions. Packets are analyzed to determine their suitability for MIMO transmission.