PUCCH DMRS Frequency Domain Orthogonalization for Channel Estimation
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Solution Overview
Problem
In 5G mobile communications, multiplexing different length physical uplink control channels (PUCCHs) in a shared resource poses challenges due to alignment requirements for demodulation reference signals (DMRS), leading to potential conflicts and poor channel estimation performance.
Innovation Solution
The method involves sending the physical uplink control channel without frequency hopping, allowing flexible placement of DMRS within a resource element set, where DMRS occupies some frequency domain subcarriers on the first time domain symbol, enabling flexible distribution and improving channel estimation performance by aligning with uplink control information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If DMRS symbols are aligned in time domain for multiplexed long PUCCHs of different lengths, then orthogonalization between DMRSs is ensured, but quantities of DMRSs in shorter PUCCHs may be insufficient leading to poor channel estimation performance
Solution Approach 1:
The patent transitions from time-domain orthogonalization to frequency-domain orthogonalization by using different comb patterns (comb0 and comb1) for DMRS. Instead of aligning DMRS symbols in time domain which causes conflicts, the invention allows DMRS of different terminal devices to occupy different frequency subcarriers within the same time slot, achieving orthogonalization in the frequency dimension while enabling flexible DMRS quantity allocation for channel estimation.
Solution Approach 2:
The patent changes the orthogonalization parameter from time-domain position alignment to frequency-domain comb pattern assignment. By assigning different comb patterns (even/odd subcarrier assignments) to different terminal devices, the system maintains orthogonalization while allowing each device to have appropriate DMRS quantities for its specific PUCCH length and channel estimation requirements.
2Productivity
If different length long PUCCHs are multiplexed in the same physical resource, then resource utilization efficiency is improved, but DMRS alignment conflicts occur leading to poor channel estimation performance
Solution Approach 1:
The patent resolves the multiplexing conflict by moving orthogonalization from time domain to frequency domain through comb patterns. This allows multiple long PUCCHs of different lengths to coexist in the same time-frequency resource without DMRS alignment conflicts, maintaining both high resource utilization and accurate channel estimation for each device.
3Measurement precision
If DMRS occupies all frequency domain subcarriers, then channel estimation performance is improved, but flexibility in multiplexing different terminal devices is reduced
Solution Approach 1:
The patent segments the frequency domain subcarriers into different comb patterns (comb0 for even subcarriers, comb1 for odd subcarriers). Each terminal device can be assigned a specific comb pattern, allowing DMRS to occupy only a subset of frequency subcarriers. This segmentation enables multiple terminal devices to multiplex simultaneously while each maintains sufficient DMRS density for accurate channel estimation.
Data Source
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AI summary
This application provides a method and device for sending a physical uplink control channel and a method and device for receiving a physical uplink control channel, to improve channel estimation performance of a terminal device. The method for sending a physical uplink control channel includes: generating a physical uplink control channel, where the physical uplink control channel carries a demodulation reference signal and uplink control information, the physical uplink control channel is sent on a resource element set, the resource element set occupies at least two time domain symbols in time domain, the demodulation reference signal is located on at least one time domain symbol of the resource element set, the at least one time domain symbol includes a first time domain symbol, the demodulation reference signal occupies some frequency domain subcarriers of the resource element set on the first time domain symbol, and the some frequency domain subcarriers are the same as frequency domain subcarriers that are occupied by the uplink control information and that are of the resource element set; and sending the physical uplink control channel.