MIMO Precoding by Physical Resource Groups for Easier Channel Estimation
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Solution Overview
Problem
In MIMO transmitters, open-loop precoding in 5G NR systems complicates channel estimation due to variations in precoder weights over time or frequency, requiring improved methods to adjust channel estimation procedures effectively.
Innovation Solution
A method involving grouping input signals into physical resource groups (PRGs), precoding these groups with varying or constant weighing coefficients, and transmitting them through multiple antennas, along with indicating weighing coefficient variations to receivers, which enables efficient channel estimation and data transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If open-loop precoding is used in MIMO transmitters, then transmit diversity and coverage are improved, but channel estimation becomes more complicated due to precoder variations
Solution Approach 1:
The patent segments the frequency spectrum into multiple subcarriers and groups them into Physical Resource Groups (PRGs). By applying precoding at the PRG level rather than individual subcarrier level, the system reduces the complexity of channel estimation while maintaining transmit diversity benefits. The receiver only needs to estimate channel characteristics for each PRG instead of every subcarrier.
Solution Approach 2:
The patent applies precoding in advance during the resource allocation phase, before actual data transmission. The precoder weights are determined and applied to groups of subcarriers (PRGs) beforehand, allowing the receiver to perform channel estimation based on known precoding patterns. This preliminary precoding action simplifies the receiver's channel estimation process.
2Adaptability or versatility
If precoder weights vary over time or frequency, then adaptability to channel conditions is improved, but the effective channel observed by the receiver undergoes variations requiring adjustment of channel estimation procedure
Solution Approach 1:
The patent implements dynamic precoding where precoder weights can vary across different PRGs in the frequency domain and across different time slots. The system adapts precoding parameters based on channel conditions while maintaining a structured approach that allows the receiver to track and estimate the effective channel by considering the known precoder variations pattern.
Solution Approach 2:
The system uses feedback mechanisms where the receiver measures the effective channel considering precoder variations and reports channel quality indicators back to the transmitter. This feedback enables the transmitter to adjust precoder weights for different PRGs to optimize performance while the receiver maintains accurate channel estimation through iterative refinement.
Data Source
AI summary
Embodiments of the present disclosure are related to transmitter and method of transmitting a signal stream from a plurality of antennas, in a communication network. The method comprises grouping, by a transmitter, a plurality of consecutive signals of the input to obtain a plurality of groups. Also, the method comprises generating a plurality of physical resource groups (PRGs) using the plurality of groups and a corresponding plurality of subcarriers and precoding each of the PRGs using one or more weighing coefficients to obtain precoded plurality of groups. Further, the method comprises processing the precoded plurality of groups to obtain a processed plurality of groups and transmitting the plurality of processed signal groups using a corresponding plurality of antennas. An indication about variation of the weighing coefficients corresponding to each of plurality of PRGs is provided by the transmitter to the one or more receivers.