Dual Preamble Structure for Mixed-Rate WLAN Coexistence
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wireless local area networks (WLANs) face challenges in coexisting between normal-rate and low-rate physical layers due to interference, as devices operating at different data rates struggle to detect and defer transmissions, leading to potential collisions and reduced network efficiency.
Innovation Solution
A system comprising a first and second preamble generation module, where the first preamble is designed for normal-rate receivers and the second preamble for low-rate receivers, allowing packets to be transmitted with either preamble first, enabling receivers to determine the intended data rate and defer access accordingly, thus minimizing interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple stations with heterogeneous capabilities (normal-rate and low-rate) coexist in a wireless network, then the network can support both high data rates and long range, but interference and collisions occur because devices cannot detect and defer transmissions at different data rates
Solution Approach 1:
The patent introduces a universal preamble structure that acts as an intermediary signal recognizable by both normal-rate and low-rate receivers. This preamble contains embedded indicators that enable devices of different capabilities to detect transmissions and defer appropriately, resolving the detection reliability issue while maintaining multi-rate support
Solution Approach 2:
The packet structure is segmented into distinct components: a universal preamble portion that all receivers can process, and a data portion that contains rate-specific information. This segmentation allows receivers to extract deferral information from the preamble without needing to decode the entire packet at their specific data rate
2Reliability
If a unified preamble structure is used for both normal-rate and low-rate transmissions, then detection reliability improves, but the preamble structure becomes more complex
Solution Approach 1:
The universal preamble uses local quality variations - specific signal characteristics and embedded indicators within the preamble structure - that enable different receiver types to identify and process the deferral information appropriate to their capabilities, maintaining reliability without requiring entirely different preamble designs
Data Source
Figure 1
Figure 2A~3
Figure 4~6
AI summary
A system including a first preamble generation module, a second preamble generation module, and a packet generation module. The first preamble generation module is configured to generate a first preamble. The first preamble includes a first training field to train receivers operating at a first data rate. The second preamble generation module is configured to generate a second preamble. The second preamble includes a second training field to train receivers operating at a second data rate. The second data rate is different than the first data rate. The packet generation module is configured to generate a packet. The packet includes the second preamble followed by the first preamble in response to the packet being transmitted at the first data rate, or the first preamble followed by the second preamble in response to the packet being transmitted at the second data rate.