Prioritized Common Subframe for Wireless Overlapping Areas
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Solution Overview
Problem
Existing wireless network systems face interference issues due to overlapping systems, leading to reduced service capability in overlapping areas, as identified in the 802.16h draft standard, where some areas cannot be served by any base station during common subframes due to lack of priority allocation.
Innovation Solution
The introduction of a subframe structure with a master/slave common subframe and a second master common subframe prioritization, where base stations can adjust their transmission power or switch to a slave subframe to minimize interference, allowing service in previously unserved overlapping areas by allocating priority and optimizing subframe usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a common subframe structure is used where all systems operate in parallel, then the capacity of slave systems is improved, but interference occurs in overlapping areas where multiple base stations transmit simultaneously
Solution Approach 1:
The patent implements periodic time-division multiplexing where base stations alternate between master and slave roles in different subframes. Each base station transmits at full power during its master subframes while other base stations remain silent or transmit at reduced power, then roles are swapped in subsequent subframes. This periodic switching allows all base stations to achieve full capacity utilization over time while preventing simultaneous interference in overlapping areas.
2Object-affected harmful factors
If a master subframe structure is used where one system has priority, then interference is reduced for the master system, but slave systems must remain silent or operate with limited capacity
Solution Approach 1:
The patent employs periodic role reversal where slave systems become master systems in alternating subframes. During subframe n, base station A is master and base station B is slave; in subframe n+1, their roles are swapped. This ensures that over a two-subframe period, both systems achieve equal access to full transmission capacity while maintaining interference-free operation during each individual subframe through the master-slave hierarchy.
3Area of stationary object
If base stations transmit at full power in overlapping areas, then service coverage is improved, but interference increases and prevents service in certain regions during common subframes
Solution Approach 1:
The patent implements dynamic transmission power control where base stations adjust their transmit power based on their master or slave status. During master subframes, the designated master base station transmits at full power to maximize coverage, while slave base stations reduce or eliminate transmission in overlapping areas. This dynamic power adjustment ensures full service coverage is achieved at all times while preventing interference through coordinated power management.
Data Source
AI summary
A subframe structure for wireless communication uses a master common subframe and second master common subframe method to give BSs different priorities to serve overlapping areas in common subframes. The subframe structure and corresponding method can increase overlapping cells' capacity and reduce interference.