Uplink DMRS Sequence Control for DFT-s-OFDM Coverage
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Solution Overview
Problem
Existing wireless communication systems face challenges in enhancing coverage, particularly in next-generation communications requiring enhanced mobile broadband, massive machine type communications, and ultra-reliable and low latency communication.
Innovation Solution
Implementing a method and device that utilize Discrete Fourier Transform-spread-Orthogonal Frequency Division Multiplexing (DFT-s-OFDM) with tone reservation and DMRS sequences, such as computer-generated sequences (CGS) and Zadoff-Chu (ZC) sequences, to optimize physical resource block allocations and DMRS symbol transmissions in user equipment (UE) and base stations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If DFT-s-OFDM with tone reservation is used for uplink transmission, then coverage is enhanced and PAPR is reduced, but device complexity increases due to DMRS sequence determination and resource block allocation
Solution Approach 1:
The patent changes the parameter of DMRS sequence length based on the number of allocated PRBs. By dynamically adjusting the sequence length parameter to match the allocated resources, the system achieves better coverage and PAPR performance while managing device complexity through parameter optimization rather than structural complexity
Solution Approach 2:
The patent introduces dynamic determination of DMRS sequence length based on the number of allocated PRBs. This dynamic adaptation allows the system to optimize performance for each specific resource allocation scenario, enhancing coverage and PAPR reduction while avoiding the need for fixed complex structures
2Measurement precision
If DMRS sequence length is determined based on all allocated PRBs including tone reservation PRBs, then measurement precision is improved, but loss of information occurs due to tone reservation overhead
Solution Approach 1:
The patent extracts the tone reservation PRBs from the total allocated PRBs when determining the DMRS sequence length. By taking out only the necessary portion (non-tone reservation PRBs) for sequence length determination, the system achieves accurate measurement without the overhead and information loss associated with including tone reservation resources
Solution Approach 2:
The patent applies different quality requirements to different parts of the resource allocation. The DMRS sequence length is optimized for the specific region where data transmission occurs (non-tone reservation PRBs), rather than uniformly across all allocated PRBs. This local optimization improves measurement precision in the actual data region while avoiding the overhead of tone reservation PRBs
Data Source
AI summary
A method of operating a user equipment (UE) in a wireless communication system is provided. The method includes receiving, from a base station, an indication for an uplink waveform of Discrete Fourier Transform-spread-Orthogonal Frequency Division Multiplexing (DFT-s-OFDM); determining a demodulation reference signal (DMRS) sequence for a DMRS symbol transmission among a computer generated sequence (CGS) and a Zadoff-Chu (ZC) sequence; determining a length of the DMRS sequence based on a number of all allocated physical resource blocks (PRBs) including first PRBs for a tone reservation and second PRBs not for the tone reservation; performing the DMRS symbol transmission using the DMRS sequence based on the determined length; and transmitting a physical uplink shared channel (PUSCH) based on the DFT-s-OFDM using the second PRBs.