WiMAX Base Station DL-MAP Repetition in Unused Regions
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Solution Overview
Problem
In WiMAX mobile communication systems, WiMAX compatible mobile stations struggle to determine the position of the downlink burst region for allocated data due to higher failure rates in receiving DL-MAP information, leading to reduced reception probability and decreased transmission speed when attempting to improve DL-MAP reception by increasing its proportion in the frame structure.
Innovation Solution
The base station reallocates DL-MAP information to unused regions within the frame structure, using a subcarrier allocating method like PUSC or AMC, and creates additional fields in the DLFP to indicate repeated insertion, thereby improving DL-MAP reception probability without significantly increasing its proportion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the proportion of DL-MAP in the frame structure is increased to improve reception probability, then the reception probability of DL-MAP is improved, but the transmission speed is decreased
Solution Approach 1:
The patent divides the frame structure into multiple segments and inserts DL-MAP information at multiple positions (including unused regions) within the frame. Instead of increasing the proportion of DL-MAP in a single location, the information is segmented and distributed across multiple locations, improving reception probability without sacrificing transmission speed.
Solution Approach 2:
The patent utilizes the time dimension by inserting DL-MAP information at multiple time positions within the frame structure. By transitioning from a single-location to multi-location insertion strategy across different time slots, the patent improves reliability without increasing the overall proportion of DL-MAP in the frame.
2Area of stationary object
If DL-MAP is transmitted with non-directional beam to all mobile stations, then coverage area is improved, but reception probability fails due to interference and signal strength issues
Solution Approach 1:
The patent performs preliminary actions by inserting multiple copies of DL-MAP information at different positions in advance within the frame structure. This allows mobile stations to have multiple opportunities to receive and decode DL-MAP information, compensating for signal strength issues in non-directional transmission.
Solution Approach 2:
The patent creates multiple copies of DL-MAP information and places them at different positions within the frame structure. These copies serve as redundant information that mobile stations can use to successfully receive DL-MAP even when signal conditions are poor, thereby improving reception probability while maintaining wide coverage.
Data Source
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AI summary
A WiMAX compatible base station (BS) includes: an allocator unit (10B, 10C) configured to allocate allocation information of the downlink burst (DL-MAP) as transmission information in a first region (MAP region), and to allocate the downlink burst as transmission information in the second region (downlink burst region); and a transmitter unit (10F) configured to transmit the allocation information of the downlink burst with a non-directional beam, and to transmit the downlink burst with a non-directional beam or a directional beam. When detecting an unused region (A) where no transmission information is allocated after allocating the transmission information in the first region and the second region in the frame structure, the allocator unit is configured to reallocate, by use of the detected unused region, the allocation information of the downlink burst as the transmission information in the first region.