OFDMA Group Identification Reduces Control Overhead
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Solution Overview
Problem
The introduction of Orthogonal Frequency Division Multiple Access (OFDMA) in radio LAN standards increases overhead due to the need for an access point to notify each station of allocated frequency bands, limiting improvements in user throughput.
Innovation Solution
A radio transmission apparatus that uses OFDMA to multiplex and transmit data to multiple radio reception apparatuses, where control information including a group identification number is transmitted to select groups, allowing data allocation based on predetermined orders and frequency resources, while also incorporating MU-MIMO transmission for spatial multiplexing, thereby reducing overhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If OFDMA is introduced to allocate frequency bands to multiple stations, then user throughput is improved, but control information overhead increases
Solution Approach 1:
The patent segments stations into groups based on their reception characteristics and channel conditions. Each group is assigned a group identifier, and the access point transmits control information at the group level rather than individually to each station. This segmentation reduces the total amount of control information overhead while maintaining efficient frequency resource allocation across multiple stations through OFDMA.
2Measurement precision
If individual frequency band notification is transmitted to each station, then accurate resource allocation is achieved, but communication efficiency decreases
Solution Approach 1:
The patent performs preliminary grouping of stations based on their reception characteristics and channel conditions before resource allocation. By pre-organizing stations into groups with similar characteristics and assigning group identifiers, the system eliminates the need for individual frequency band notifications to each station. This preliminary action maintains accurate resource allocation while significantly improving communication efficiency by reducing control information transmission time.
Data Source
AI summary
A radio transmission apparatus selects any one group from a plurality of groups each indicating a combination of a plurality of radio reception apparatuses, notifies at least a plurality of radio reception apparatuses belonging to the selected group of an identification number assigned in advance to the selected group, and allocates transmission data addressed to the radio reception apparatuses belonging to the selected group to each of a plurality of frequency resources based on order of the radio reception apparatuses, which is determined in advance in the selected group.