Adaptive Cyclic Prefix for OFDM Coaxial Networks
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Solution Overview
Problem
Coaxial networks using OFDM signals face throughput reduction due to the bandwidth consumption of long cyclic prefixes, which are necessary to address multipath issues.
Innovation Solution
Implementing a channel-shortening time-domain equalizer (TEQ) processor that determines and configures shorter cyclic prefixes based on the delay spread of the coaxial channel, allowing for reduced bandwidth usage and improved throughput by shortening the channel effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a long cyclic prefix is used to address multipath issues, then multipath handling is improved, but bandwidth consumption increases and throughput decreases
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the cyclic prefix length based on the measured delay spread of the coaxial channel. Instead of using a fixed long cyclic prefix, the system measures the actual channel characteristics and configures the cyclic prefix length to match the delay spread, thereby optimizing the balance between multipath handling and bandwidth efficiency.
Solution Approach 2:
The patent implements dynamics by making the cyclic prefix length adjustable and adaptive rather than fixed. The system continuously monitors channel conditions and dynamically reconfigures the cyclic prefix length to match the current delay spread, allowing the system to adapt to changing channel characteristics and optimize performance.
2Reliability
If a long cyclic prefix is used to cover delay spread, then multipath issues are addressed, but bandwidth consumption increases
Solution Approach 1:
The patent changes the parameter of cyclic prefix length to match the actual delay spread measurement. By measuring the channel's delay spread and configuring the cyclic prefix accordingly, the system eliminates unnecessary bandwidth consumption while maintaining adequate coverage for multipath issues.
Solution Approach 2:
The patent extracts the excessive portion of the cyclic prefix that does not contribute to multipath handling. By measuring the actual delay spread and setting the cyclic prefix length to match it, the system removes unnecessary bandwidth consumption while retaining only the essential cyclic prefix length needed for multipath coverage.
Data Source
AI summary
A network communication device is receive packet-based orthogonal frequency division multiplexed (OFDM) transmissions from one or more other devices in a network over a communication channel. The network communication device may determine a delay spread of the communication channel based on receipt of a probe signal from a transmitting device, configure a channel filter to effectively shorten the channel based on the delay spread, and instruct the transmitting device to shorten a length of a cyclic prefix for subsequent packet-based OFDM transmissions to be received from the transmitting device over the channel.