Orthogonal UWB Pulse Combinations for Multipath Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Ultra-wideband radio communication systems face challenges with pulse position modulation due to the need for synchronous clocks and are sensitive to multipath interference, degrading Bit Error Rate (BER) and complicating demodulation.
Innovation Solution
The method involves forming symbols from multiple bits using combinations of orthogonal ultra-wideband pulses, which are then transferred as radio signals, utilizing Gaussian functions to simplify implementation and improve signal discrimination with filters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If pulse position modulation is used for ultra-wideband communication, then binary information can be transmitted using short pulses, but the system becomes sensitive to multipath interference and requires synchronous clocks between transmitter and receiver
Solution Approach 1:
The invention segments the single pulse into multiple orthogonal ultra-wideband pulses (at least three). Each pulse is orthogonal to the others, creating distinct signal components that can be independently processed. This segmentation allows the receiver to distinguish between direct path and multipath signals, reducing sensitivity to multipath interference while maintaining transmission efficiency.
Solution Approach 2:
The invention uses composite signal structures by combining multiple orthogonal ultra-wideband pulses to form a composite modulated signal. This composite approach creates a more robust transmission that maintains the advantages of pulse position modulation while reducing vulnerability to multipath effects through the diversity provided by orthogonal pulse components.
2Ease of operation
If differential encoding is performed to address frequency deviation and time drift, then clock synchronization issues are mitigated, but system performance degrades in terms of bit error rate
Solution Approach 1:
By segmenting the signal into multiple orthogonal pulses, the system can maintain better clock synchronization without requiring differential encoding. The orthogonal structure provides inherent reference points that facilitate synchronization while preserving signal integrity, thus avoiding the performance degradation associated with differential encoding.
3Device complexity
If a single pulse is used for symbol transmission, then the transmission is simple, but the system is highly sensitive to multipath propagation and interference
Solution Approach 1:
The single pulse is segmented into multiple orthogonal ultra-wideband pulses, creating a more complex but robust signal structure. This segmentation provides diversity that reduces sensitivity to multipath interference while maintaining manageable system complexity through systematic signal processing.
Solution Approach 2:
The invention transitions from a one-dimensional single pulse to a multi-dimensional signal space using orthogonal pulses. This dimensional expansion allows the system to exploit additional degrees of freedom for signal discrimination and multipath resistance, reducing harmful effects while controlling complexity.
Data Source
Figure 1~3
Figure 2a~2c
Figure 4~8
AI summary
The invention relates to a method for transmitting binary information over a radio link using an ultra-wideband modulation. The method comprises the following steps of: forming (E70) symbols comprising a plurality of bits; selecting (E71), for each symbol formed, a combination of at least two ultra-wideband pulses which are orthogonal in pairs from a set of combinations of the at least two ultra-wideband pulses which are orthogonal in pairs; transferring (E72) a radio signal for each combination of at least two selected ultra-wideband pulses which are orthogonal in pairs.