Split Radio Architecture for Car-2-X Antenna Placement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In Car-2-X wireless communication systems using multiple antennas, the separation of antennas by large distances poses challenges for signal processing due to the need for long and expensive RF cables and high-speed digital links, which are costly and prone to interference.
Innovation Solution
A split signal processing system where bit log-likelihood ratios (LLRs) are generated by each antenna's signal processing module and combined for joint demodulation, using a master-slave configuration to reduce data rate requirements and enable efficient processing of signals from multiple antennas, allowing for asynchronous data exchange and training symbol-based channel estimation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If antennas are separated by large distances to improve spatial diversity and flexibility, then antenna placement flexibility and spatial diversity are improved, but the cost and complexity of connecting cables and digital links increase
Solution Approach 1:
The receiver is divided into multiple independent signal processing modules, each associated with one antenna. Each module performs complete signal processing independently and outputs bit LLRs, which are then combined. This segmentation allows antennas to be placed far apart without requiring complex centralized processing connections.
2Reliability
If independent RF frontend and digital baseband processing are used for each antenna to achieve optimal diversity performance, then signal processing performance is improved, but hardware cost and system complexity increase
Solution Approach 1:
The system segments the processing into independent modules where each antenna has its own RF frontend, FEM, and signal processing chain. This segmentation maintains optimal diversity performance while allowing modular implementation that reduces overall system complexity through independence of modules.
Solution Approach 2:
Bit log-likelihood ratios (LLRs) serve as an intermediary representation that enables independent processing of each antenna's signal while still allowing joint demodulation. The LLRs combine information from multiple antennas in a way that achieves diversity gain without requiring complex real-time coordination between antenna modules.
3Reliability
If long RF cables and high-speed digital links are used to connect separated antennas to centralized processing, then signal processing capability is maintained, but cost and interference susceptibility increase
Solution Approach 1:
By segmenting the signal processing functionality into distributed modules at each antenna, the system eliminates the need for long RF cables and high-speed digital links to a centralized processor. Each module processes signals locally and only needs to exchange bit LLRs, which are less susceptible to interference and require less bandwidth.
Solution Approach 2:
The invention extracts the essential processing functions (RF frontend, FEM, signal processing, FFT, channel estimation, LLR generation) and places them at each antenna location. This extraction removes the need for complex connecting infrastructure while maintaining full signal processing capability at each distributed node.
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
The present invention relates to a split signal processing system comprising: multiple antennas for receiving transmitted signals carrying an information-bearing symbol; multiple signal processing modules associated with the respective antennas and being configured to generate respective bit log-likelihood ratio (LLR) sequences, each corresponding to the information-bearing symbol; and a LLR combiner for combining the bit LLR sequences received from the multiple signal processing modules.