Semi-Open Loop Uplink Precoding for 5G CQI Estimation
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Solution Overview
Problem
5G networks face challenges in providing reliable transmission diversity for uplink channels due to random precoder selection by mobile devices, which can lead to performance degradation and difficulty in Channel Quality Indicator (CQI) estimation by the network.
Innovation Solution
The implementation of a semi-open loop based transmission diversity system, where a candidate set of precoders (weight vectors) is defined, allowing mobile devices to randomly select a precoder from this set, while ensuring the network can estimate CQI using previously used precoders, thereby maintaining control over precoder selection and improving network performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If mobile devices randomly select precoders for uplink transmissions, then transmission diversity is improved, but CQI estimation accuracy deteriorates
Solution Approach 1:
The patent segments the precoder selection process into two parts: the network device segments the precoders into codebooks and determines which precoders were used by the mobile device, while the mobile device randomly selects from those determined precoders. This segmentation allows the network to maintain control over the precoder set for CQI estimation while the mobile device still achieves transmission diversity through random selection.
Solution Approach 2:
The patent implements a feedback mechanism where the mobile device reports information about which precoders it has selected to the network device. This feedback enables the network device to accurately estimate CQI based on the actual precoders used, resolving the contradiction between random selection for diversity and the need for accurate CQI estimation.
2Reliability
If mobile devices randomly select precoders from a large set, then transmission diversity is enhanced, but network control over precoder selection deteriorates
Solution Approach 1:
The patent segments the precoder selection process into two parts: the network device segments the precoders into codebooks and determines which precoders were used by the mobile device, while the mobile device randomly selects from those determined precoders. This segmentation allows the network to maintain control over the precoder set for CQI estimation while the mobile device still achieves transmission diversity through random selection.
Solution Approach 2:
The patent changes the parameter of precoder selection from completely random to semi-random, where the random selection is constrained within a controlled set determined by the network device. This parameter change maintains transmission diversity benefits while preserving network control and adaptability.
Data Source
AI summary
Facilitating semi-open loop based transmission diversity for uplink transmissions in a communications network is provided herein. A system can comprise a processor and a memory that stores executable instructions that, when executed by the processor, facilitate performance of operations. The operations can comprise receiving, from a network device, information related to a sounding reference resource. The information related to the sounding reference resource can be based on a sounding reference signal resource transmission detected during a defined time interval. The operations can also comprise, based on a selected weight vector cycling, selecting a weight vector from defined weight vectors stored in the memory, resulting in a selected weight vector. Further, the operations can comprise transmitting, to the network device, a signal that comprises the selected weight vector multiplied with the sounding reference signal, during the selected weight vector cycling.