Local Oscillator Startup Phase Detection for I/Q Discontinuity Correction
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Solution Overview
Problem
Wireless devices face phase discontinuity issues in LO signals due to non-continuous operation of LO generators, which affects frequency conversion and power consumption.
Innovation Solution
A wireless device with an LO generator, phase detector, single-tone generator, and phase corrector is used to detect and correct phase discontinuity in LO signals by swapping or rotating I and Q signals, allowing for continuous phase operation while conserving battery power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the LO generator is periodically powered on and off to conserve battery power, then power consumption is reduced, but phase discontinuity occurs in the LO signal
Solution Approach 1:
The phase detector detects the phase of the LO signal immediately when the LO generator is powered on, before the signal is used for frequency conversion. This preliminary phase detection allows the system to identify phase discontinuity and apply correction in advance, ensuring phase continuity is maintained while still allowing the LO generator to be powered off during idle periods to save battery power
Solution Approach 2:
The phase detector continuously monitors the phase of the LO signal and provides feedback to the phase corrector. When phase discontinuity is detected, the feedback mechanism triggers the phase corrector to swap or rotate the I and Q signals, automatically correcting the phase issue without requiring continuous operation of the LO generator, thus maintaining both power efficiency and phase continuity
2Stability of the object's composition
If the LO generator operates continuously to maintain phase continuity, then phase stability is improved, but power consumption increases
Solution Approach 1:
The system uses the LO signal itself to detect its own phase discontinuity. The phase detector samples the LO signal generated by the LO generator, identifies phase issues, and triggers correction automatically. This self-service mechanism eliminates the need for continuous operation or external monitoring systems, allowing the LO generator to be powered off when not needed while automatically maintaining phase continuity when powered on
Solution Approach 2:
The phase corrector dynamically changes the phase parameter of the LO signal by swapping or rotating the I and Q signals based on detected phase discontinuity. This parameter change approach allows the system to maintain phase continuity through corrective action rather than continuous operation, reducing power consumption while preserving signal integrity
Data Source
AI summary
Techniques for detecting and correcting phase discontinuity of a local oscillator (LO) signal are disclosed. In one design, a wireless device includes an LO generator and a phase detector. The LO generator generates an LO signal used for frequency conversion and is periodically powered on and off. The phase detector detects the phase of the LO signal when the LO generator is powered on. The detected phase of the LO signal is used to identify phase discontinuity of the LO signal. The wireless device may further include (i) a single-tone generator that generates a single-tone signal used to detect the phase of the LO signal, (ii) a downconverter that downconverts the single-tone signal with the LO signal and provides a downconverted signal used by the phase detector to detect the phase of LO signal, and (iii) phase corrector that corrects phase discontinuity of the LO signal in the analog domain or digital domain.