UWB Sequence Set Design for Dense Multi-User Ranging
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Solution Overview
Problem
In multi-user dense scenarios, existing UWB communication systems face significant inter-user interference due to the limited number of supported sequences, leading to high cross-correlation between local reference sequences and non-target sending devices, which affects synchronization and ranging accuracy.
Innovation Solution
Implement a first sequence set that includes at least two 121-length, 133-length, 73-length, or 91-length sequences with specific cross-correlation thresholds, allowing each channel to support a larger quantity of sequences, reducing inter-user interference by using binary sequences for non-coherent receivers and ternary sequences for coherent receivers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a limited number of sequences are used in each channel, then the system complexity is reduced, but the number of supported users decreases and inter-user interference increases in multi-user dense scenarios
Solution Approach 1:
The patent introduces a new parameter dimension by using different sequence lengths (73, 91, 121, 133) to differentiate sequences across multiple channels. This parameter change allows each channel to support multiple sequences with low cross-correlation, thereby increasing the total number of supported users without significantly increasing system complexity. The sequence length parameter becomes a key differentiator that enables scalable multi-user support.
2Adaptability or versatility
If more sequences are supported per channel, then multi-user capacity increases, but the cross-correlation between sequences increases leading to higher inter-user interference
Solution Approach 1:
The patent applies local quality by optimizing sequence properties specifically for low cross-correlation performance. Different sequence lengths (73, 91, 121, 133) are carefully selected and designed to have specific local correlation characteristics that minimize interference. Each sequence within a channel is locally optimized to maintain low cross-correlation with other sequences in the same channel, thereby supporting more users without proportionally increasing interference.
3Measurement precision
If ternary sequences are used for coherent receivers, then synchronization accuracy is improved, but compatibility with non-coherent receivers is reduced
Solution Approach 1:
The patent achieves universality by designing a sequence set that serves multiple receiver types. The sequence set includes sequences optimized for coherent receivers (with perfect periodic autocorrelation) while also being processable by non-coherent receivers. The system can selectively apply different processing methods based on receiver type, making the same sequence set universally applicable to both coherent and non-coherent architectures.
Solution Approach 2:
The patent segments the sequence set into different categories based on their properties and suitable receiver types. Some sequences are specifically designed for coherent reception with optimal autocorrelation properties, while the overall sequence set structure allows non-coherent receivers to process them with acceptable performance. This segmentation allows each receiver type to utilize sequences most suitable for its architecture.
Data Source
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AI summary
A communication method and a communication apparatus are provided. The communication method includes: A first device generates a first ultra-wideband UWB signal based on a first sequence in a first sequence set, where the first sequence set includes at least two 121-length sequences, at least two 133-length sequences, at least two 73-length sequences, or at least two 91-length sequences. The first device sends the first UWB signal to a second device, and correspondingly, the second device receives the first UWB signal. The second device processes the first UWB signal based on the first sequence. According to embodiments of this application, inter-user interference, and in particular, inter-user interference in a multi-user dense scenario, can be reduced.