Spatial Diversity for mmWave Small Cell Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Millimeter Wave (mmWave) beamforming systems face reliability and performance issues due to unreliable TX/RX paths, radio link failures, and service interruptions, particularly in mobility scenarios, as they rely heavily on directional transmissions and are vulnerable to channel characteristics and beamforming challenges in small cells.
Innovation Solution
A spatial diversity scheme is proposed that uses multiple different beams for data and control communication, allowing for duplicate or incremental transmission and reception, enhancing mobility robustness and critical data delivery by combining physical-layer resources with other protocol layers, thereby avoiding Radio Link Failure (RLF) and Handover Failure (HOF).
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If directional beamforming is used in mmWave systems, then data rate and beamforming gain are improved, but reliability and robustness deteriorate due to vulnerable propagation paths and intermittent links
Solution Approach 1:
The patent segments the communication link into multiple diverse spatial paths using multiple beams at different spatial levels. Instead of relying on a single directional beam, the system divides the transmission into multiple independent paths (different beams, different spatial levels) to provide redundancy and maintain reliability while preserving the high data rate capability of directional beamforming.
Solution Approach 2:
The patent changes the spatial parameters of transmission by using multiple beams with different beam patterns, beam widths, and spatial orientations. This includes varying beamforming parameters such as beam direction, beam width, and spatial level to create diverse propagation paths that are less susceptible to individual link failures.
2Reliability
If multiple beams and spatial levels are used for diversity, then reliability is improved, but device complexity and decision complexity increase
Solution Approach 1:
The patent organizes multiple beams into a hierarchical structure with different spatial levels, where each level serves specific functions. This segmentation allows the system to manage complexity by dividing beam management into manageable levels rather than treating all beams uniformly, reducing the decision complexity while maintaining reliability benefits.
Solution Approach 2:
The patent performs preliminary beam configuration and spatial level establishment before actual data transmission. By pre-configuring multiple beams and their spatial relationships, the system reduces real-time decision complexity during operation, as the framework for beam selection and management is already in place.
3Reliability
If spatial diversity scheme is implemented, then robustness against link failures is improved, but signaling overhead and processing increase
Solution Approach 1:
The patent merges multiple diversity schemes (spatial diversity through multiple beams, time diversity through TDM, frequency diversity through FDM, and code diversity through CDMA) into a unified communication framework. This integration allows the system to achieve robustness against link failures while optimizing signaling overhead by coordinating all diversity mechanisms rather than managing them separately.
Solution Approach 2:
The patent creates a universal beam management framework that handles multiple functions (control signaling, data transmission, diversity management, handover coordination) through a single integrated system. This multi-functionality reduces overall signaling overhead by eliminating redundant signaling for separate diversity mechanisms and consolidating control functions.
Data Source
AI summary
A method of providing spatial diversity for critical data delivery in a beamformed mmWave small cell is proposed. The proposed spatial diversity scheme offers duplicate or incremental data/signal transmission and reception by using multiple different beams for the same source and destination. The proposed spatial diversity scheme can be combined with other diversity schemes in time, frequency, and code, etc. for the same purpose. In addition, the proposed spatial diversity scheme combines the physical-layer resources associated with the beams with other resources of the same or different protocol layers. By spatial signaling repetition to avoid Radio Link Failure (RLF) and Handover Failure (HOF), mobility robustness can be enhanced. Mission-critical and/or time-critical data delivery can also be achieved without relying on retransmission.