Digital Transport in Distributed Antenna Systems
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In digital Distributed Antenna Systems (DAS), bandwidth is wasted as all digital samples need to be transported at a rate sufficient to cover the full range of frequencies, even when only specific portions contain signals of interest, leading to inefficient use of fiber bandwidth.
Innovation Solution
The system segregates the digitized RF spectrum into smaller spectral regions containing relevant signals, processes them independently, and transmits each region over a common serial transport link using timeslots allocated based on their respective bandwidths, discarding non-relevant information to conserve bandwidth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If all digital samples are transported at a rate sufficient to cover the full RF frequency range, then complete frequency coverage is achieved, but fiber bandwidth is wasted due to inclusion of non-relevant frequency portions
Solution Approach 1:
The patent segments the digitized RF spectrum into multiple smaller spectral regions, each containing relevant signals of interest. Each spectral region is processed independently through separate signal paths, allowing selective transport of only relevant frequency portions over the fiber, thereby improving bandwidth efficiency while maintaining adaptability through configurable spectral region definitions
Solution Approach 2:
The patent applies different processing and sampling rates to different spectral regions based on their specific bandwidth requirements. Each spectral region is allocated timeslots proportional to its bandwidth, enabling optimized resource allocation where each portion of the spectrum receives treatment matched to its actual needs rather than a uniform approach
2Productivity
If the entire digitized RF spectrum is transported, then all frequency information is preserved, but the number of timeslots required increases reducing transport efficiency
Solution Approach 1:
The patent extracts only the relevant spectral regions containing signals of interest from the complete digitized RF spectrum. By discarding non-relevant frequency information and transporting only the extracted spectral regions, the system increases transport efficiency while preserving all necessary signal information for wireless communication
Solution Approach 2:
The patent dynamically allocates timeslots to spectral regions based on their respective bandwidths and signal requirements. The system can adaptively adjust which spectral regions are transported and how many timeslots each receives, optimizing transport efficiency according to actual signal conditions and priority requirements
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A communication device (500) includes a reception path circuit (506) configured to output digitised radio frequency spectrum at a sampling rate based on input signals. A logic device (503), coupled to the reception path circuit, is configured to receive digitised radio frequency spectrum at the input sampling rate. The logic device produces sets of digitised baseband data samples at a plurality of sampling rates, each set of digitised baseband data samples corresponding to a distinct spectral region of an analogue radio frequency spectrum. The logic device maps each of the sets of digitised baseband data samples to a corresponding set of timeslots of a serial data stream transport frame. A complimentary communication device (500) includes a transmission path circuit (504) configured to output signals based on a received digitised radio frequency spectrum. A logic device (503), coupled to the transmission path circuit, is configured to receive an input transport frame having sets of timeslots, each set of timeslots including a set of digitised baseband data samples at one of a plurality of sampling rates. Each set of timeslots corresponds to a distinct spectral region of analogue radio frequency spectrum. The logic device is configured to generate a further set of digitised data samples for each set of the timeslots at an output sampling rate and sums at least two of the further sets of digitised data samples to produce a set of output data samples at the output sampling rate.