OTFDM Symbol Generation With Embedded RS for Low-Latency 6G
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing 5G-NR DFT-s-OFDM waveforms require at least one data symbol and one reference symbol, doubling latency and increasing RS overhead, which is not suitable for 6G systems demanding low latency, high data rates, and flexible RS overhead.
Innovation Solution
A method for generating OTFDM symbols by time-multiplexing input data and reference sequences using spreading operations, followed by DFT and spectrum shaping to reduce PAPR and enable efficient transmission within a single OFDM symbol.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional DFT-S-OFDM uses separate data symbol and reference symbol, then channel estimation accuracy is improved, but transmission latency is doubled and RS overhead increases to 50%
Solution Approach 1:
The patent merges data and reference sequences into a single OTFDM symbol by time-multiplexing spread data with embedded reference sequences. This combining approach allows channel estimation to be performed within the same symbol period, eliminating the need for separate reference symbols and reducing latency while maintaining estimation accuracy through the spread spectrum structure.
Solution Approach 2:
The patent introduces a time-multiplexing dimension within the single OTFDM symbol, where reference sequences are embedded at specific time positions within the data symbol. This dimensional reorganization allows reference sequences to coexist with data in the same symbol period, enabling simultaneous data transmission and channel estimation without increasing overall symbol duration.
2Loss of energy
If spectrum shaping filter is applied to reduce PAPR, then power efficiency is improved, but effect on higher modulation schemes is limited
Solution Approach 1:
The patent replaces traditional spectrum shaping filtering with a spreading-based approach. Instead of using mechanical filtering operations that have limited effectiveness on higher modulation schemes, the invention uses spreading sequences to achieve PAPR reduction through constructive interference and signal distribution, providing a more versatile solution that works effectively across different modulation types.
3Speed
If single OFDM symbol transmission is used to reduce latency, then transmission speed is improved, but flexible RS overhead and reliable channel estimation become challenging
Solution Approach 1:
The patent implements dynamic reference sequence embedding within the single OTFDM symbol, where the position, density, and distribution of reference sequences can be flexibly adjusted based on channel conditions and service requirements. This dynamic approach allows the system to adapt RS overhead to different scenarios while maintaining low latency single-symbol transmission.
Data Source
AI summary
Embodiments of the present disclosure relate to a method for transmitting a waveform. The method comprising generating. The method comprising generating, by a transmitter, at least one of: at least one input data or control and at least one reference sequence (RS). Also, the method comprises performing spreading operation on the at least one input data or control with a spread sequence to generate at least one spread data or control sequence and time-multiplexing the at least one spread data or control sequence with the at least one RS, to generate a multiplexed sequence. Further, the method comprises generating an OTFDM symbol using the multiplexed sequence. Also, the method transmits the RS and the data or control in one OTFDM symbol, which eventually offers low PAPR, spreading gain and low latency.