Adaptive Tone Erasure for OFDM Interference
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Solution Overview
Problem
Wireless communication systems face challenges in maintaining reliable data transmission and reducing interference in wideband wireless networks, particularly in the presence of in-band interference, which affects user experience and power consumption.
Innovation Solution
The implementation of an adaptive transmitter tone erasure technique, where jammed sub-carriers are identified and erased from the transmitted signal, and corresponding erasure bits are inserted to maintain constant interleaver block size, reducing interference and power consumption by configuring the transmitter and receiver devices to adapt to interference conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If wideband wireless networks transmit data over large bandwidths, then data transmission rate is improved, but interference from in-band signals increases
Solution Approach 1:
The patent segments the wideband spectrum into multiple sub-carriers (frequency bins) that can be individually processed. By dividing the broad frequency band into discrete sub-carriers, the system can identify and erase only the specific sub-carriers affected by interference while maintaining transmission on unaffected sub-carriers, thus preserving overall data transmission rate while mitigating interference.
Solution Approach 2:
The patent applies local quality by treating each sub-carrier independently based on its specific interference conditions. The erasure mask is applied selectively to individual sub-carriers that are identified as jammed, rather than erasing entire bands. This localized approach maintains signal quality on non-interfered sub-carriers while removing interference-affected sub-carriers.
2Reliability
If interference mitigation techniques are applied, then reliability of communication is improved, but power consumption increases
Solution Approach 1:
The patent applies partial action by erasing only the specific sub-carriers that are identified as jammed, rather than applying interference mitigation across the entire spectrum. The erasure mask selectively nulls only the affected frequency bins, minimizing the processing overhead and power consumption while maintaining communication reliability on the remaining sub-carriers.
3Productivity
If erasure bits are inserted to maintain constant interleaver block size, then data transmission efficiency is improved, but device complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-calculating and inserting erasure bits into the data stream before interleaving, based on the erasure mask that identifies jammed sub-carriers. This preliminary insertion of erasure bits at known positions allows the interleaver to maintain constant block size without requiring complex dynamic adjustments during transmission, simplifying the overall device architecture.
Data Source
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AI summary
In embodiments, an adaptive tone erasure technique is applied to orthogonal frequency division multiplexing (OFDM) communications, such as ECMA-368 standard ultra-wideband (UWB) communications. A transmitter obtains jammed sub-carrier information and calculates an erasure mask. The jammed sub-carriers are nulled before transmitting to a receiver. In accordance with the erasure mask, bits falling on the jammed sub-carriers are replaced by erasure bits before interleaving, keeping the interleaver block size constant notwithstanding variations in the number of the jammed sub-carriers. The receiver also obtains the jammed sub-carrier information and the erasure mask. After the receiver deinterleaves the constant size blocks, it decodes the data without the erasure bits. The transmitter may detect the jammed sub-carriers itself, or obtain the information from the receiver. The receiver similarly may detect the jammed sub-carriers itself, or obtain the information from the transmitter.