Antenna Sub-Array Selection for Millimeter Wave Acquisition
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Solution Overview
Problem
In wireless communication systems, especially at millimeter wave frequencies, user equipment (UE) faces challenges in balancing acquisition time and reliability when selecting antenna sub-arrays for network connection, as connecting and measuring each sub-array sequentially is time-consuming, while acquiring measurements for only a subset or stopping early may result in using a suboptimal antenna sub-array.
Innovation Solution
The UE performs an initial acquisition procedure with a subset of antenna sub-arrays, selects one for a random access procedure, and then selectively measures signals to determine if a different sub-array should be used for communication with the base station, allowing for a tradeoff between acquisition time and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the UE connects each antenna sub-array sequentially to the RF chain and performs signal measurements for each sub-array, then the reliability of antenna selection is improved, but the acquisition time becomes excessively long
Solution Approach 1:
The patent segments the antenna sub-arrays into two distinct groups: a first group used for initial access and random access procedures, and a second group reserved for conditional measurement and selection. This segmentation allows the UE to perform initial connection using only the first group, significantly reducing acquisition time, while preserving the option to measure and select from the second group if communication quality requirements demand higher reliability.
Solution Approach 2:
The patent applies partial action by performing measurements on only a subset of antenna sub-arrays (the first group) during initial access, rather than measuring all available sub-arrays. This partial measurement approach achieves sufficient reliability for initial connection establishment without the time penalty of exhaustive measurement, while the system retains the capability to perform additional measurements on the second group if needed for optimized communication.
2Loss of time
If the UE only acquires measurements for a subset of antenna sub-arrays or stops acquiring measurements early, then the acquisition time is reduced, but the UE may communicate using a suboptimal antenna sub-array
Solution Approach 1:
The patent implements preliminary action by designating the first group of antenna sub-arrays specifically for initial access and random access procedures before any measurement or selection decisions are made. This preliminary assignment ensures that the UE can establish connection quickly using a predetermined subset, reducing acquisition time. The system then performs measurements on this first group to determine communication quality, and only if results are insufficient does it proceed to measure the second group, thereby achieving a balance between speed and reliability.
Data Source
AI summary
Techniques are described for wireless communication at a user equipment (UE) having a plurality of antenna sub-arrays. One method includes performing an initial acquisition procedure with a base station using each antenna sub-array of a first subset of antenna sub-arrays, in which the first subset includes two or more antenna sub-arrays of the plurality of antenna sub-arrays; selecting an antenna sub-array from the first subset; and performing a random access procedure with the base station using the selected antenna sub-array. Another method includes performing a random access procedure with a base station using a first antenna sub-array in the plurality of antenna sub-arrays; selecting a second antenna sub-array in the plurality of antenna sub-arrays to use for communication with the base station after performing the random access procedure; and transmitting to the base station, on a beam, a scheduling request state indicating the selected second antenna sub-array.