Null Guard Interval for Inter-Block Interference in Faster-than-Nyquist Signalling
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Solution Overview
Problem
Faster-than-Nyquist signalling in wireless communications leads to inter-symbol interference, increasing the probability of errors due to overlapping symbols, which existing technologies struggle to mitigate effectively.
Innovation Solution
The method involves using time packing with a null guard interval in each block of symbols, where symbols overlap in the time domain, and employing G-to-minus-half (GTMH) precoding and decoding to reduce estimation complexity and mitigate inter-block interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If Faster-than-Nyquist signalling is used to increase data throughput, then productivity is improved, but inter-symbol interference increases causing higher error probability
Solution Approach 1:
The transmitted signal is divided into multiple blocks, where each block contains a specific number of symbols. By segmenting the data stream into manageable blocks and processing them independently with GTMH decoding, the system can handle inter-symbol interference more effectively while maintaining high data throughput through Faster-than-Nyquist signalling.
Solution Approach 2:
G-to-minus-half (GTMH) precoding is applied to the data blocks before transmission to pre-compensate for expected inter-symbol interference effects. The receiver then applies corresponding GTMH decoding to undo the precoding and mitigate interference. This preliminary action allows the system to operate at Faster-than-Nyquist rates while maintaining reliability.
2Productivity
If symbols are packed closer in time to increase throughput, then productivity is improved, but inter-block interference increases
Solution Approach 1:
The signal is segmented into discrete blocks with clear boundaries. Each block is independently encoded and transmitted, allowing the receiver to process and decode blocks separately. This segmentation prevents inter-block interference from accumulating while maintaining the time-packed Faster-than-Nyquist signalling structure for high throughput.
Solution Approach 2:
The system changes the temporal parameters of symbol transmission by using non-uniform spacing within blocks while maintaining block boundaries. This parameter adjustment allows symbols to be packed closer together (increasing throughput) while the block structure and GTMH processing prevent inter-block interference.
Data Source
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AI summary
A method of transmitting data over a wireless communications channel comprises transmitting a plurality of blocks (70), in which each block (70) comprises a plurality of symbols (71, 72, 73, 74, 75) representing the data. The symbols are transmitted using time packing, or Faster-than-Nyquist signalling, such that each symbol in a block overlaps in the time domain with at least one other symbol in the block. A null guard interval (77) is included in each block, having a length that means that inter-symbol interference is not a cause of inter-block interference.