Subframe Configuration for Relay Station Mobility in Multi-Hop BWA Systems
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In multi-hop relay Broadband Wireless Access (BWA) communication systems, the mobility of Relay Stations (RSs) and the resulting near-far interference between direct and relay communications within a cell pose challenges for efficient cell search and synchronization, particularly in environments with fluctuating traffic and varying call demands.
Innovation Solution
The system configures subframes to time-multiplex relay and direct communications, providing synchronization channels and allocating resources to support RS mobility, thereby eliminating near-far interference by separating BS-MS, RS-MS, and RS-RS links in distinct periods of the subframe, ensuring efficient cell search and synchronization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If multi-hop relay service is deployed to expand cell coverage and provide high-speed data channels, then network coverage and data transmission capability are improved, but near-far interference between direct and relay communications increases
Solution Approach 1:
The subframe is segmented into multiple periods (first period and second period) to separate direct service transmissions from relay service transmissions. This temporal segmentation allows different services to occupy different time slots, eliminating near-far interference while maintaining expanded cell coverage through relay stations.
Solution Approach 2:
The system implements periodic time-division multiplexing where direct and relay services are transmitted in alternating periods within each subframe. This periodic action ensures that relay stations and base stations transmit in dedicated time slots, preventing interference between direct and relay communications while enabling extended network coverage.
2Adaptability or versatility
If relay stations are introduced to provide flexible network configuration, then adaptability to environmental changes is improved, but synchronization and cell search complexity increases
Solution Approach 1:
Synchronization channels are transmitted in advance during designated time slots before data transmission begins. This preliminary action ensures that mobile stations and relay stations acquire necessary synchronization information before actual communication starts, simplifying the synchronization process while maintaining flexible network reconfiguration capabilities.
Solution Approach 2:
The patent introduces synchronization channels as intermediary elements that facilitate coordination between direct and relay services. These channels act as mediators that carry synchronization information, enabling mobile stations and relay stations to maintain proper timing relationships without increasing overall system complexity.
3Object-affected harmful factors
If time-division multiplexing is used to separate direct and relay services, then near-far interference is eliminated, but subframe configuration complexity increases
Solution Approach 1:
The subframe is divided into distinct temporal segments (first period for direct service, second period for relay service) that are clearly delimited. This segmentation approach eliminates interference by ensuring no overlap between service types while maintaining relatively simple configuration through standardized period definitions.
Data Source
AI summary
An apparatus and method for configuring a subframe to support a relay service in a multi-hop relay BWA communication system are provided. The apparatus includes at least one of a BS-MS link subframe, a primary RS-MS link subframe, and a BS-secondary RS link subframe are configured in a first period of the subframe, and at least one of a BS-primary RS link subframe, an RS-RS link subframe, and a secondary RS-MS link subframe is configured in a second period of the subframe.