Asymmetric Carrier Assignment for Multi-Carrier Wireless Systems
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Solution Overview
Problem
In multi-carrier wireless communication systems, existing technologies face challenges in efficiently decoupling forward and reverse link assignments, leading to suboptimal spectral efficiency and increased overhead, particularly in scenarios with asymmetric data rate requirements.
Innovation Solution
The proposed solution involves asymmetric carrier assignment and time-division multiplexing of data rate control (DRC) and acknowledgment (ACK) channels, allowing for efficient use of reverse link resources by transmitting DRC and ACK channels on a single reverse link carrier, while optimizing forward link carriers based on application types and channel conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If symmetric carrier assignment is used for forward and reverse links, then system simplicity is maintained, but spectral efficiency deteriorates in asymmetric data rate scenarios
Solution Approach 1:
The patent applies asymmetry by allowing different numbers of carriers to be assigned to forward and reverse links. Specifically, multiple forward link carriers can be assigned to an access terminal while only a single reverse link carrier is assigned, matching the asymmetric nature of data rate requirements where forward link typically requires higher data rates. This resolves the contradiction by improving spectral efficiency through asymmetric assignment while maintaining manageable complexity through standardized single-carrier reverse link procedures.
Solution Approach 2:
The patent segments the carrier assignment into independent forward and reverse link configurations. Forward link carriers are assigned based on data rate requirements, while reverse link uses a dedicated single carrier for control channels. This segmentation allows optimization of each link independently, improving overall spectral efficiency without creating complex coupled assignment rules.
2Productivity
If separate reverse link carriers are assigned for each forward link carrier, then link mapping is simplified, but reverse link overhead increases
Solution Approach 1:
The patent merges multiple forward link carriers with a single reverse link carrier for control channel transmissions. DRC (Data Rate Control) and ACK (Acknowledgment) channels are multiplexed on one reverse link carrier instead of requiring separate carriers for each forward link. This merging reduces reverse link overhead and improves resource efficiency while the patent manages the mapping complexity through defined association rules between forward and reverse carriers.
Solution Approach 2:
The single reverse link carrier serves multiple functions by carrying DRC, ACK, and other control information for multiple forward link carriers simultaneously. This multi-functional use of the reverse link carrier improves resource efficiency by eliminating the need for dedicated carriers for each function, while the patent maintains clarity through structured multiplexing and association mechanisms.
3Quantity of substance
If multiple reverse link carriers are used for DRC and ACK channels, then channel capacity is increased, but system overhead increases
Solution Approach 1:
The patent combines DRC and ACK channel transmissions on a single reverse link carrier using time-division multiplexing. Instead of allocating separate carriers for DRC and ACK, both control channels share the same reverse link resource, increasing effective capacity utilization while reducing overhead by eliminating redundant carrier assignments and associated signaling.
4Adaptability or versatility
If forward and reverse link carriers are tightly coupled, then assignment management is simplified, but adaptability to different application types deteriorates
Solution Approach 1:
The patent segments the assignment management into independent forward and reverse link configurations that can be optimized separately for different application types. Forward link carrier assignment can be adjusted based on application requirements (e.g., high data rate applications receive more forward carriers), while reverse link maintains a standardized single-carrier configuration. This segmentation provides adaptability without requiring complex coupled assignment rules for each application type.
Solution Approach 2:
The patent introduces dynamic carrier assignment on the forward link based on application type and channel conditions, while keeping the reverse link configuration relatively static. The system can dynamically allocate different numbers of forward carriers to different access terminals or adjust forward carrier assignments in response to changing conditions, providing adaptability without the complexity of dynamically adjusting reverse link assignments.
Data Source
AI summary
A method and system for de-coupling forward and reverse link assignment for multi-carrier wireless communication systems. A method may assign two or more forward link code division multiple access (CDMA) carriers to transmit data from a base station to an access terminal; assign one or more reverse link CDMA carriers to transmit data from the access terminal to the base station; and limit reverse link overhead transmissions corresponding to the two or more forward link CDMA carriers.