Reciprocal Beam Training for FDD Millimeter-Wave Links
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The overhead of beam training in millimeter wave communication systems, particularly in FDD systems, is excessive due to the need for separate training of uplink and downlink channels, and the increasing number of antennas and users, with existing solutions failing to address this effectively.
Innovation Solution
A method and device for FDD millimeter wave communication that involves generating reduced analog sub-codebooks by selecting optimal channel qualities and using them for beam training, reducing the overhead by employing a user terminal and base station codebook reduction process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If separate beam training is performed for uplink and downlink channels in FDD systems, then channel estimation accuracy is improved, but beam training overhead increases significantly
Solution Approach 1:
The patent performs uplink beam training first to obtain optimal uplink beamforming parameters, then uses these results as preliminary information for downlink beam training. This preliminary action reduces the search space for downlink training, maintaining accuracy while reducing overhead.
Solution Approach 2:
The patent implements a feedback mechanism where channel quality indicators and beamforming parameters obtained from uplink training are fed back to guide the downlink training process. This feedback allows the system to adapt the downlink training based on uplink channel conditions, reducing redundant training operations.
2Productivity
If the number of antennas is increased to improve communication capacity, then spectral efficiency is improved, but beam training overhead increases due to more codebook combinations
Solution Approach 1:
The patent segments the large codebook into multiple sub-codebooks based on channel conditions and spatial directions. Instead of training through all possible antenna combinations, the system divides the search space into manageable segments, reducing training overhead while maintaining the ability to utilize all antennas for high-capacity communication.
Solution Approach 2:
The patent applies partial action by performing beam training only on a subset of codebook combinations that are most likely to be optimal based on preliminary channel measurements. This partial training approach avoids the excessive overhead of exhaustive search while still achieving near-optimal beamforming for large antenna arrays.
3Adaptability or versatility
If codebook size is increased to support more users, then system scalability is improved, but beam training overhead increases due to more weight vector combinations
Solution Approach 1:
The patent performs preliminary user pairing and grouping based on channel quality indicators before beam training. This preliminary action organizes users into smaller groups that can be trained simultaneously or sequentially, allowing the system to scale to more users without proportionally increasing the overhead for each user's beam training.
Solution Approach 2:
The patent designs a universal beam training framework that can handle multiple users with different codebook sizes and configurations through a common procedure. This multi-functional approach allows the same training mechanism to adapt to varying system scales, maintaining overhead efficiency whether serving few or many users.
Data Source
AI summary
A wireless communication method and a wireless communication device. An electronic device for a user equipment in a wireless communication system, including a processing circuit configured to receive, from a base station, channel state information reference signal with a set of reception filters, perform channel estimation on a downlink channel from the base station to the user equipment, select, from the set of reception filters, one or more particular reception filters corresponding to respective channel estimation results that satisfy a first predetermined condition, and signal, from the user equipment to the base station, sounding reference signal with one or more particular transmission filters, wherein the one or more particular transmission filters and one or more particular reception filters are reciprocal respectively.