DFT-s-OFDM Pre-DFT Spreading for Beamforming
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless communication systems face challenges in efficiently managing multiple-access technologies for supporting diverse user equipment (UE) communications, particularly in terms of spectral efficiency and beamforming techniques, especially in New Radio (NR) and Long Term Evolution (LTE) networks.
Innovation Solution
The implementation of an apparatus and method for wireless communication that utilizes discrete Fourier transform (DFT)-spread-orthogonal frequency division multiplexing (DFT-s-OFDM) waveforms with unique pre-DFT-spreading sequences for digital beamforming, enabling efficient signal decoding and transmission across multiple beams.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple-access technologies are used to support diverse UE communications, then the system can accommodate more users and services, but spectral efficiency deteriorates
Solution Approach 1:
The patent segments the communication signal into multiple beams, with each beam carrying a DFT-s-OFDM waveform associated with a unique pre-DFT-spreading sequence. This segmentation allows different user equipment to receive dedicated beam signals, supporting diverse communications while maintaining spectral efficiency through targeted transmission rather than broad coverage.
Solution Approach 2:
The patent applies local quality by assigning unique pre-DFT-spreading sequences to different beams, creating localized signal characteristics optimized for specific spatial directions. Each beam has tailored signal properties (different spreading sequences) that improve spectral efficiency in its specific coverage area while the system overall supports diverse UE communications across multiple beams.
2Use of energy by moving object
If digital beamforming is implemented to improve spectral efficiency, then communication performance improves, but system complexity increases
Solution Approach 1:
The patent applies preliminary action by performing DFT spreading on the signal before OFDM modulation and beamforming. The unique pre-DFT-spreading sequences are generated and applied in advance, which simplifies the overall processing structure. This preliminary spreading operation enables efficient digital beamforming without requiring complex real-time signal generation, thus improving spectral efficiency while managing system complexity.
3Measurement precision
If unique pre-DFT-spreading sequences are used for each beam, then signal decoding precision improves, but processing complexity increases
Solution Approach 1:
The patent applies parameter changes by utilizing unique pre-DFT-spreading sequences with distinct parameters (different sequence values, lengths, or patterns) for each beam. These parameter variations enable the receiver to distinguish between different beams and decode signals with high precision. The mathematical properties of these sequences (orthogonality, correlation characteristics) provide the precision needed while the structured approach to generating them keeps processing complexity manageable.
Data Source
AI summary
Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive, from a wireless communication device, an aggregated signal including a plurality of frequency division multiplexed (FDM) signals corresponding to a plurality of beams, each of the plurality of signals comprising a discrete Fourier transform (DFT)—spread-orthogonal frequency division multiplexing (DFT-s-OFDM) waveform associated with a unique pre-DFT-spreading sequence of a plurality of pre-DFT-spreading sequences. The UE may decode the plurality of FDM signals based at least in part on the plurality of pre-DFT-spreading sequences. Numerous other aspects are described.