Truncated Zadoff-Chu Reference Signals for Lower-Complexity Zero-Tail OFDM
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Solution Overview
Problem
Existing wireless communication systems face increased complexity and inefficiency due to the addition of zero head and zero tail sequences in DFT-s-OFDM waveforms, which alter the Zadoff-Chu sequence properties essential for channel estimation, leading to higher computational demands.
Innovation Solution
A truncated Zadoff-Chu sequence is generated by removing bits from the head and tail and adding zero-bit header and tail samples, maintaining ZC properties, and processed using DFT and IFFT to transmit and receive signals with reduced complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If zero head and zero tail sequences are added to maintain Zadoff-Chu properties in DFT-s-OFDM waveforms, then channel estimation accuracy is improved, but device complexity and computational demand increase
Solution Approach 1:
The patent extracts and removes the zero head and zero tail sequences from the DFT-s-OFDM waveform, keeping only the essential Zadoff-Chu sequence. This extraction eliminates the harmful addition of zero sequences while preserving the core ZC properties needed for channel estimation, thereby reducing computational complexity without sacrificing estimation accuracy
Solution Approach 2:
Instead of adding zero sequences to maintain ZC properties (the conventional approach), the patent inverts the approach by removing the zero sequences and directly using the truncated Zadoff-Chu sequence. This inversion reveals that the zero sequences are actually the problematic element, and their removal simplifies the system while maintaining the necessary autocorrelation properties for channel estimation
2Stability of the object's composition
If zero head and zero tail sequences are added to DFT-s-OFDM waveforms, then waveform structure is improved, but power expenditure increases
Solution Approach 1:
The patent extracts and removes the energy-consuming zero head and zero tail sequences from the waveform structure. By eliminating these redundant zero-valued samples, the system reduces the computational power required for processing while maintaining the essential structural integrity of the Zadoff-Chu sequence through proper truncation
3Device complexity
If Zadoff-Chu sequence is truncated to reduce complexity, then device complexity is reduced, but sequence properties may be altered
Solution Approach 1:
The patent applies parameter changes by carefully controlling the truncation length of the Zadoff-Chu sequence. By selecting appropriate truncation parameters that preserve the autocorrelation properties, the system maintains the essential sequence characteristics needed for channel estimation while reducing the overall sequence length and associated computational complexity
Data Source
AI summary
Methods, systems, and devices for wireless communications are described. A transmitting device may generate a first time-domain reference signal sequence of a first sequence length, and may truncate the first sequence length to a second sequence length and may append a header portion and a tail portion to the truncated first time-domain reference signal sequence. The transmitting device may perform a discrete Fourier transform (DFT) on the truncated first time-domain reference signal sequence to generate a frequency-domain reference signal sequence associated with a phase constant, and may perform an inverse fast-Fourier transform (IFFT) on the result of the DFT. The transmitting device may then transmit the result of the IFFT to a receiving device, which may further process the signal by performing a fast-Fourier transform (FFT), dividing by the phase constant, and taking the conjugate of the received sequence.