Multi-QAM Demodulation Using Shared Oscillator Signals
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for demodulating multiple Quadrature Amplitude Modulation (QAM) signals require an equal number of Numerically Controlled Oscillators (NCOs) proportional to the number of signals, leading to high costs and complexity, especially when channel bonding increases data transfer speeds.
Innovation Solution
A system and method that uses one or two oscillators to demodulate multiple QAM signals by generating phase-separated signals, allowing demodulators to produce demodulated signals using these oscillators, reducing the number of oscillators needed and optimizing silicon area and power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an equal number of NCOs is used for each QAM signal, then demodulation accuracy is maintained, but system cost and complexity increase significantly
Solution Approach 1:
The patent makes a single oscillator serve multiple functions by generating a base oscillator signal that is reused across multiple demodulators through mathematical processing. Instead of dedicating one NCO per QAM signal, one oscillator's output is shared and processed to derive the necessary sinusoidal and cosinusoidal signals for all demodulators, thereby reducing the number of oscillators from N to 1 while maintaining demodulation capability for all N QAM signals.
Solution Approach 2:
The patent creates virtual copies of oscillator signals through mathematical computation rather than physical duplication. The base oscillator signal is copied and transformed using sine and cosine functions at different phase offsets to generate the required local carrier signals for each demodulator, eliminating the need for physical NCO copies while preserving signal integrity.
2Productivity
If more QAM signals are demodulated simultaneously, then data transfer speed increases, but the number of oscillators required increases proportionally
Solution Approach 1:
The patent enables a single oscillator to support multiple QAM signal demodulations simultaneously by using mathematical processing to generate the required carrier signals. The base oscillator signal is processed through sine and cosine functions with different phase offsets to create the necessary local carriers for each demodulator, allowing the system to scale data transfer capacity without proportionally increasing the number of oscillators.
Solution Approach 2:
The patent changes the approach from varying the number of oscillators to varying the phase parameters of a single oscillator's output. By adjusting phase offsets in the mathematical processing of the base oscillator signal, the system generates differentiated carrier signals for multiple demodulators, allowing increased productivity without increasing the quantity of oscillators.
3Adaptability or versatility
If multiple NCOs are implemented to demodulate multiple carrier signals, then signal demodulation capability is maintained, but silicon area and power consumption increase
Solution Approach 1:
The patent merges multiple oscillator functions into a single physical oscillator by combining the signal generation and mathematical processing stages. Instead of having separate NCO blocks for each demodulator, the system merges them into one oscillator followed by shared mathematical processing logic that distributes the necessary signals to all demodulators, thereby reducing silicon area while maintaining full demodulation capability.
Solution Approach 2:
The single oscillator and its associated mathematical processing unit serve multiple demodulators simultaneously, providing universal signal generation capability. The same oscillator output is processed with different phase offsets to generate the required local carriers for each QAM signal, eliminating the need for dedicated oscillator circuits in each demodulator and reducing overall silicon footprint.
4Ease of manufacture
If the number of oscillators is reduced, then system cost decreases, but maintaining demodulation performance becomes challenging
Solution Approach 1:
The patent replaces the mechanical approach of using multiple physical oscillators with a mathematical processing approach. Instead of relying on multiple hardware NCO blocks, the system uses software-based or digital signal processing techniques to generate the required sinusoidal and cosinusoidal signals from a single oscillator, reducing hardware cost while maintaining performance through computational methods.
Solution Approach 2:
The patent maintains demodulation performance by carefully controlling phase parameters in the mathematical processing of the single oscillator signal. By adjusting phase offsets in the sine and cosine function calculations, the system generates accurately phased local carrier signals for each demodulator, ensuring reliable demodulation performance despite using fewer physical oscillators.
Data Source
AI summary
A system and method demodulate N QAM signals (N being a positive integer equal to or greater than 1) substantially simultaneously using, for example, one or two oscillators, regardless of how many QAM signals need to be demodulated.