OFDMA Resource Reservation for IEEE 802.11ax Coexistence
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Solution Overview
Problem
The IEEE802.11ax standard faces challenges in coexisting with existing IEEE802.11 standards, particularly when introducing Orthogonal Frequency Division Multiple Access (OFDMA), as it increases overhead and limits throughput improvement due to inadequate carrier sense mechanisms.
Innovation Solution
A radio transmission and receiving apparatus system that employs a new access scheme, where resource reserving signals and responses are used to manage radio resources efficiently, allowing coexistence with existing systems by using cyclic shifts and shared information to optimize channel allocation and reduce interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If OFDMA is introduced to IEEE802.11ax standard with virtual carrier sense, then frequency efficiency is enhanced and user throughput is improved, but overhead increases and compatibility with existing IEEE802.11 standards deteriorates
Solution Approach 1:
The patent segments the resource reservation response into two distinct parts: a first response signal that uses existing IEEE802.11 standard formats for compatibility, and a second response signal that carries OFDMA-specific resource allocation information. This segmentation allows the system to maintain compatibility with legacy standards while implementing advanced OFDMA functionality, thereby improving user throughput without excessively increasing overhead that would compromise compatibility.
Solution Approach 2:
The patent introduces a new dimensional approach by adding a second resource reservation response signal that operates in parallel with the traditional first response signal. This additional dimension allows the system to carry extra OFDMA-specific information without interfering with the existing carrier sense mechanism, thus enhancing frequency efficiency and user throughput while maintaining compatibility with existing standards.
2Productivity
If OFDMA is introduced to IEEE802.11ax standard, then frequency efficiency is enhanced by arranging orthogonal sub-carriers densely, but coexistence with existing IEEE802.11 standards becomes difficult
Solution Approach 1:
The patent implements a dual-function resource reservation mechanism where the first resource reservation response signal serves both legacy IEEE802.11 systems and OFDMA systems. The first response uses standard formats recognizable by existing IEEE802.11 equipment, while the second response provides additional OFDMA-specific information. This multi-functionality enables dense orthogonal sub-carrier arrangement for improved frequency efficiency while maintaining coexistence capability with existing standards.
Solution Approach 2:
The patent introduces an intermediary mechanism in the form of a second resource reservation response signal that mediates between OFDMA-specific resource allocation needs and legacy IEEE802.11 compatibility requirements. This intermediary carries additional information about sub-carrier allocation and resource mapping without disrupting the existing carrier sense mechanism, thereby enabling dense sub-carrier arrangement while preserving coexistence capability.
3Adaptability or versatility
If simple virtual carrier sense of existing IEEE802.11 standard is introduced to IEEE802.11ax, then compatibility is maintained, but throughput improvement is limited
Solution Approach 1:
The patent applies preliminary action by having terminals transmit a second resource reservation response signal that contains pre-configured OFDMA-specific information about resource allocation, sub-carrier mapping, and frequency efficiency parameters. This preliminary information exchange enables the system to establish efficient OFDMA resource utilization before actual data transmission begins, thereby achieving throughput improvement while maintaining compatibility through the traditional first response signal.
Solution Approach 2:
The patent implements a feedback mechanism where the second resource reservation response signal provides detailed information about terminal-specific resource allocation, channel conditions, and frequency efficiency metrics. This feedback enables the access point to optimize OFDMA resource allocation dynamically, improving throughput while the first response signal maintains compatibility with existing virtual carrier sense mechanisms.
Data Source
AI summary
OFDMA transmission by a plurality of terminal apparatuses is realized in a communication system in which CSMA/CA is premised and existing terminal apparatuses coexist. A communication method of a radio receiving apparatus of the invention includes the steps of: receiving a resource reserving signal which is transmitted from the radio transmission apparatus and which includes information indicating that the signal is addressed to the plurality of radio receiving apparatuses; and transmitting a resource reserving response signal to the radio transmission apparatus by using at least one radio resource with which the resource reserving signal is received, in which at least part of information included in the resource reserving response signal is identical to information included in the first resource reserving response signal transmitted by another of the radio receiving apparatuses.