Communications Device Frequency Band Switching and Calibration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Low-cost communications devices used in licensed spectrum often suffer from inaccuracies due to inexpensive components, leading to reduced communication throughput and interference, especially in congested unlicensed spectrum, where accurate timing and frequency adjustments are not readily available.
Innovation Solution
A method and apparatus that allow a communications device to select between different modes of operation based on received signals from a second device, adjusting parameters such as tone spacing and frequency to align with a first set of parameters, and making device setting changes to switch between frequency bands while maintaining calibration adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If inexpensive components are used in access terminals to reduce cost, then the terminal becomes more affordable and accessible to more users, but the terminal exhibits clock and frequency errors that reduce communication accuracy and throughput
Solution Approach 1:
The patent implements a feedback mechanism where the access terminal receives timing and frequency reference signals from the access router and uses these signals to detect and adjust for inaccuracies in its own oscillator. The terminal performs correction operations by altering the voltage on its voltage controlled oscillator based on the received reference signals, creating a closed-loop feedback system that continuously improves timing and frequency accuracy without requiring expensive components.
Solution Approach 2:
The patent changes the operating parameters of the voltage controlled oscillator by adjusting the control voltage based on received reference signals. The terminal modifies its frequency and timing parameters dynamically to match the access router's reference, transforming the inaccurate oscillator output into an accurate communication signal through parameter adjustment rather than hardware replacement.
2Reliability
If access terminals perform frequent frequency and timing adjustments to maintain accuracy, then communication reliability improves, but device complexity and processing overhead increase
Solution Approach 1:
The feedback mechanism simplifies the control complexity by providing direct reference signals from the access router that guide the terminal's adjustment operations. The terminal only needs to process these reference signals and make corresponding adjustments to its oscillator, rather than performing complex autonomous frequency estimation and correction algorithms, thereby reducing processing overhead while maintaining reliability.
3Ease of manufacture
If low-cost access routers are used in non-licensed spectrum to reduce system cost, then overall system affordability increases, but the access router cannot provide accurate timing and frequency reference signals, reducing communication quality
Solution Approach 1:
The patent makes the reference signal generation dynamic by allowing the access router to transmit reference signals at intervals rather than continuously. The access terminal dynamically adjusts its operation based on received reference signals, enabling low-cost routers to provide adequate reference functionality without requiring continuous high-precision signal transmission, thus maintaining communication quality while reducing system cost.
4Ease of manufacture
If access terminals operate in congested unlicensed spectrum without accurate timing, then device cost remains low, but interference with other devices increases and communication throughput decreases
Solution Approach 1:
The feedback mechanism enables access terminals to continuously monitor and adjust their timing and frequency based on reference signals from the access router. This closed-loop control allows terminals to maintain accurate synchronization even in congested unlicensed spectrum, reducing interference with other devices while keeping device costs low, as the adjustment is performed through software-controlled voltage changes rather than expensive hardware.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Methods and apparatus for supporting multiple modes of communication operation, e.g., with different parameters and/or frequency bands being used in the different modes of operation are described. One or more adjustments are made based on a signal or signals received in a first frequency band from a second communications device, e.g., an access router with reliable timing. The communications device selects between and operates in either the first frequency band, e.g., a WAN frequency band, or in a second frequency band, e.g., a LAN frequency band. The WAN and LAN frequency bands may be non-overlapping. One or more parameters used in the second frequency band have a predetermined relationship to one or more parameters used for communications in the first frequency band making the adjustment based on the signal received in the first frequency band relevant and useful to support communications in the second frequency band.