Hybrid Multiplexing for Massive MIMO Antenna Scaling
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Solution Overview
Problem
The implementation of Analog Radio over Fiber (A-RoF) in C-RAN is hindered by the high cost and complexity of broadband Digital to Analog Converter (DAC) and Analog to Digital Converter (ADC) modules required for massive MIMO applications, which are needed to manage the increased number of antennas in mobile networks.
Innovation Solution
A hybrid multiplexing/de-multiplexing method and apparatus that divides intermediate frequency sub-bands into clusters, using software-defined intermediate frequency multiplexers and analog hardware cluster multiplexers to reduce the bandwidth requirements and cost, allowing for efficient conversion and modulation of signals, thereby reducing the need for full-bandwidth converters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If broadband ADC/DAC modules are used to support massive MIMO applications, then the number of supported antennas increases, but the cost and complexity increase significantly
Solution Approach 1:
The patent divides the broadband frequency spectrum into multiple narrowband sub-bands, allowing each ADC/DAC module to operate only in its assigned narrowband range. This segmentation enables support for massive MIMO antennas while using low-complexity narrowband converters instead of expensive broadband ones.
2Quantity of substance
If broadband ADC/DAC modules are deployed, then more antenna channels can be processed, but the system cost increases
Solution Approach 1:
By segmenting the frequency spectrum into narrow sub-bands and assigning each to a separate low-cost narrowband ADC/DAC module, the system achieves massive MIMO capability without requiring expensive broadband converters, thereby reducing overall system cost.
Solution Approach 2:
Multiple narrowband ADC/DAC modules work together in a modular architecture to collectively process wideband signals for massive MIMO, making the system scalable and cost-effective compared to using a single broadband module.
3Ease of manufacture
If narrowband DAC/ADC modules are used with frequency division multiplexing, then cost is reduced, but signal processing complexity increases
Solution Approach 1:
The patent introduces frequency domain multiplexing and demultiplexing as intermediary processes that manage the coordination between multiple narrowband ADC/DAC modules, handling the signal processing complexity in a structured manner while maintaining cost benefits.
Data Source
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AI summary
The present disclosure discloses a method and an apparatus for hybrid multiplexing/de-multiplexing in a passive optical network, the method comprising steps of: dividing N first intermediate frequency sub-bands averagely into M clusters, wherein each of the clusters contains K first intermediate frequency sub-bands and N=M*K, and wherein each of the K first intermediate frequency sub-bands carries a baseband digital electrical signal; selecting, by a software defined first intermediate frequency multiplexer, the baseband digital electrical signals of K first intermediate frequency sub-bands from the N first intermediate frequency sub-bands for software defined frequency division multiplexing and forming a cluster; and frequency division multiplexing, by an analog hardware cluster multiplexer, analog electrical signals of the M clusters on a second intermediate frequency sub-band. The hybrid analog radio over fiber scheme according to the present disclosure achieves the balance between the software defined intermediate frequency multiplexer and the hardware cluster multiplexer and multi-stage frequency division multiplexing, and has very high cost effectiveness and configuration flexibility.