Multiplexing-Spread Chip Sequence for Noise-Resistant Communication
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Solution Overview
Problem
Existing communication methods, such as DS-SS and M-ary methods, face challenges in improving the signal-to-noise ratio (SN ratio) in noisy environments, particularly with broadband noises, and struggle with maintaining orthogonality of code sequences and achieving high data transmission speeds.
Innovation Solution
A transmission signal generating/detecting method using code sequences that multiplexes spreading, coupling, and localizing code sequences to generate a multiplexing-spread chip sequence, which is then transformed and de-spread to improve SN ratio and enable high-speed data transmission by mapping data to shift time, amplitude, and polarity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If DS-SS method is used to remove narrowband noises, then SN ratio is improved, but broadband noises cannot be removed
Solution Approach 1:
The patent segments the code sequence into multiple segments (first code sequence and second code sequence) with different properties. The first code sequence is optimized for narrowband noise resistance while the second code sequence addresses broadband noise. This segmentation allows each segment to specialize in combating different noise types, resolving the contradiction between narrowband and broadband noise performance.
Solution Approach 2:
The patent creates a composite code sequence structure by combining multiple code sequences with different characteristics. The composite structure integrates the advantages of different code sequences - one providing narrowband noise resistance and another providing broadband noise resistance - thereby achieving simultaneous protection against both noise types that neither individual code sequence could achieve alone.
2Adaptability or versatility
If orthogonal code sequences are used for spectrum spread modulation, then multiple access is enabled, but orthogonality is lost under noises causing erroneous detection
Solution Approach 1:
The patent divides the orthogonal code sequence into multiple segments, where each segment maintains partial orthogonality properties. This segmentation allows the system to preserve enough orthogonality for multiple access functionality while reducing the vulnerability of the entire sequence to noise-induced orthogonality loss, thereby maintaining detection accuracy in noisy environments.
Solution Approach 2:
The patent applies different local qualities to different segments of the code sequence. Certain segments are designed with enhanced properties for maintaining orthogonality under noise, while other segments optimize for multiple access capabilities. This local differentiation allows the system to maintain overall performance despite noise conditions.
3Productivity
If M-ary method is used for fast transmission, then transmission speed is improved, but SN ratio improvement rate is limited
Solution Approach 1:
The patent segments the transmission process into multiple stages using different code sequences. The first code sequence handles high-speed transmission requirements while the second code sequence provides enhanced SN ratio improvement through its specific correlation properties. This segmentation allows the system to achieve both fast transmission and significant SN ratio improvement, overcoming the limitation of conventional M-ary methods.
Data Source
AI summary
The present invention provides a transmission method which generates and sends a transmission signal generated from a multiplexing OFDM signal or a multiplexing wavelet-OFDM signal employing a multiplexing-spread chip sequence in which a chip of a code sequence for spread and a code sequence for combination, and a chip of a code sequence for localization are multiplied and multiplexed, and a receiving method which makes a high SN ratio improvement rate possible by converting the received signal to a frequency domain to acquire the multiplexing-spread chip sequence and by performing de-spreading and localizing processing to detect a localized pulse. According to the data transmission using the transmission and receiving method, data is mapped into a code sequence, and the receiving side can detect the data as the kind of code sequence, the shift time of a localized pulse and the polarity at a high SN ratio improvement rate.