Zadoff-Chu Sequence Preambles for Wireless Synchronization
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Solution Overview
Problem
Current wireless communication systems face inefficiencies in synchronizing communications between electronic devices due to the computational expense of estimating time and frequency offsets, which requires multiple Fast Fourier Transform (FFT) and Inverse Fast Fourier Transform (IFFT) operations.
Innovation Solution
The use of Zadoff-Chu sequences with specific root values and their inverse modulus counterparts in wireless signals, allowing for the generation of preambles that enable efficient estimation of time and frequency offsets through a single IFFT operation, thereby simplifying synchronization processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple FFT and IFFT operations are used to estimate time and frequency offsets, then measurement precision is improved, but device complexity and computational resources increase
Solution Approach 1:
The patent segments the synchronization process into two distinct parts: a first preamble for frequency offset estimation and a second preamble for time offset estimation. This segmentation allows each preamble to be optimized for its specific function, enabling accurate offset estimation while reducing overall computational complexity compared to using multiple FFT/IFFT operations on a single combined signal
Solution Approach 2:
The patent extracts the frequency offset estimation function and time offset estimation function into separate preambles with distinct Zadoff-Chu sequence root values. By taking out these functions separately, the system avoids the need for multiple iterative FFT/IFFT operations, thereby reducing computational complexity while maintaining measurement precision
2Measurement precision
If multiple FFT and IFFT operations are performed, then measurement precision is improved, but productivity decreases
Solution Approach 1:
By segmenting the synchronization process into separate frequency offset estimation (using first preamble) and time offset estimation (using second preamble), the patent enables parallel or sequential processing that is computationally more efficient than multiple FFT/IFFT operations, thereby improving synchronization speed while maintaining precision
Solution Approach 2:
The patent performs preliminary frequency offset estimation using the first preamble before time offset estimation using the second preamble. This preliminary action allows the system to correct frequency offsets beforehand, simplifying subsequent time synchronization operations and improving overall processing efficiency
3Measurement precision
If multiple FFT and IFFT operations are used, then measurement precision is improved, but energy consumption increases
Solution Approach 1:
The patent extracts frequency offset and time offset estimation into separate preambles, eliminating the need for multiple energy-intensive FFT/IFFT operations. This extraction reduces computational energy consumption while preserving the precision benefits of separate estimation processes
Solution Approach 2:
The patent changes the parameter approach by using different Zadoff-Chu sequence root values for different estimation functions instead of relying on iterative FFT/IFFT operations. This parameter change fundamentally reduces the computational complexity and associated energy consumption while maintaining measurement precision
Data Source
AI summary
In an example method, a first device determines a first Zadoff-Chu sequence having a first root value, and a second Zadoff-Chu sequence having a second root value, where the first second root value is an inverse modulus of the first root value. Further, the first device generates a wireless signal including (i) a first preamble generated based, at least in part, on the first Zadoff-Chu sequence, (ii) a second preamble generated based, at least in part, on the second Zadoff-Chu sequence, and (iii) a payload. Further, the first device transmits the wireless signal from the first device to a second device.