RRU Stream Antenna Mapping Reduces BBU Fronthaul Bandwidth
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Solution Overview
Problem
The increasing use of large-scale antenna arrays in wireless communication systems leads to a significant increase in fronthaul data traffic between baseband units (BBUs) and remote radio units (RRUs), resulting in deployment difficulties and higher costs, especially in remotely connected scenarios.
Innovation Solution
The proposed solution involves a data transmission method where the RRU performs stream to antenna mapping processing on data received from the BBU, reducing the need for extensive data transmission by processing and transmitting data directly to user equipment, and vice versa, using techniques like inverse Fast Fourier Transformation (IFFT) and cyclic prefix insertion/removal, along with dynamic antenna weighted values for optimized data mapping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If large-scale antenna arrays are used in wireless communication systems, then communication capacity and coverage are improved, but fronthaul data traffic between BBU and RRU increases significantly
Solution Approach 1:
The patent segments the baseband processing functions by introducing a front-end unit that handles resource mapping and stream-to-antenna mapping, separating these functions from the main BBU. This segmentation allows the BBU to transmit only essential control information and user data to the RRU, rather than all processed baseband signals, thereby reducing fronthaul traffic while maintaining large-scale MIMO capabilities.
Solution Approach 2:
The patent introduces a new functional dimension in the signal processing chain by adding the front-end unit between BBU and RRU. This front-end unit performs resource mapping and stream-to-antenna mapping operations, creating an additional processing layer that enables more efficient data compression and reduction of fronthaul bandwidth requirements.
2Reliability
If large-scale antenna arrays are deployed, then system performance is improved, but deployment complexity and costs increase
Solution Approach 1:
The patent extracts the resource mapping and stream-to-antenna mapping functions from the traditional BBU-RRU architecture and places them in a separate front-end unit. This extraction simplifies the RRU design and reduces the complexity of remote deployment, as the RRU only needs to handle radio frequency functions while the complex baseband processing is centralized in the BBU or front-end unit.
Solution Approach 2:
The front-end unit serves multiple functions: it performs resource mapping, stream-to-antenna mapping, and acts as an interface between the BBU and RRU. This multi-functionality reduces the overall system complexity by consolidating several processing tasks into a single unit, making large-scale antenna array deployment more manageable.
3Ease of operation
If all baseband processing is centralized in BBU, then control and management are simplified, but data transmission bandwidth requirements increase
Solution Approach 1:
The front-end unit performs preliminary resource mapping and stream-to-antenna mapping operations before data is transmitted to the RRU. By completing these processing steps in advance, the system reduces the amount of data that needs to be transmitted over the fronthaul interface, thereby reducing bandwidth requirements while maintaining centralized control in the BBU.
Data Source
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AI summary
The present invention provides a data transmission method, a remote radio unit RRU, and a baseband unit BBU. The method includes: receiving, by the RRU, stream data sent by the BBU, where the stream data is obtained after the BBU performs resource mapping processing on to-be-transmitted downlink data; performing, by the RRU, stream to antenna mapping processing on the stream data; and sending, by the RRU, mapping-processed data to user equipment by using an antenna. In the data transmission method of embodiments of the present invention, service stream data is transmitted between the BBU and the RRU. This can reduce data traffic between the BBU and the RRU, so as to reduce fronthaul data bandwidth between the BBU and the RRU.