OFDM Subcarrier Allocation for Wireless Interference
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Solution Overview
Problem
Current wireless networks, particularly those using orthogonal frequency division multiplexing (OFDM), face challenges in efficiently allocating data across subcarriers due to interference from adjacent channels, leading to reduced reliability and throughput, especially as the number of devices and network complexity increase.
Innovation Solution
The system allocates data to subcarriers based on their priority and position within the channel, associating higher priority data with more reliable subcarriers, which are typically those in middle or edge positions relative to adjacent channels, to maximize transmission quality and minimize errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If data is allocated to subcarriers without considering position and reliability, then the allocation process is simple, but transmission reliability decreases due to adjacent channel interference
Solution Approach 1:
The patent applies local quality by differentiating subcarrier reliability based on their positions within the channel. Middle subcarriers are identified as having higher reliability due to reduced adjacent channel interference, while edge subcarriers have lower reliability. This spatial differentiation of quality enables targeted allocation strategies that match data priority levels with appropriate subcarrier positions, thereby improving transmission reliability without requiring complex real-time analysis of each subcarrier's actual performance.
2Reliability
If high priority data is transmitted on all subcarriers regardless of position, then throughput is maximized, but error rate increases due to interference on edge subcarriers
Solution Approach 1:
The patent changes the allocation parameter from uniform distribution to position-based differentiated allocation. By modifying the allocation strategy to consider subcarrier position (middle vs. edge) and data priority (high vs. low), the system dynamically adjusts which data goes to which subcarrier. This parameter change enables the system to maintain high throughput by utilizing all subcarriers while reducing error rates by placing high-priority data on more reliable middle subcarriers and low-priority data on edge subcarriers.
3Ease of operation
If subcarriers are used without position-based allocation, then the system is easy to implement, but service quality deteriorates under adjacent channel interference
Solution Approach 1:
The patent applies preliminary action by pre-establishing the relationship between subcarrier position and reliability before actual data transmission begins. The system预先 identifies middle subcarriers as having higher reliability and edge subcarriers as having lower reliability due to adjacent channel interference patterns. This preliminary characterization of subcarrier quality allows the allocation algorithm to make informed decisions without requiring complex real-time measurements or adjustments during transmission, thus maintaining implementation simplicity while improving service quality.
Data Source
Figure 1A~1C
Figure 2A~2B
Figure 3
AI summary
Multiplexed unequal error protection for wireless networks is disclosed. A device may determine reliability associated with a first subcarrier of a channel including the first subcarrier and at least one second subcarrier. The reliability of the first subcarrier may be determined based on the position of the first subcarrier relative to each at least one second subcarrier. High priority data may be assigned to the first subcarrier for transmission if the first subcarrier is determined to have a higher reliability than the at least one second subcarrier. For example, the channel may be an orthogonal frequency division multiplexed (OFDM) channel and higher reliability may be associated with a first subcarrier that is in a middle position of the plurality of subcarriers within the OFDM channel. In another example, higher reliability may be associated with a first OFDM subcarrier that is adjacent to an unused OFDM channel bandwidth.