Carrier Demodulation by Phase-Shifted Sampling
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Solution Overview
Problem
Existing demodulators in wireless communication systems are complex and costly due to the need for separate inphase and quadrature phase signal processing, which is not efficiently handled by current demodulation methods, especially at high data rates and varying modulation standards.
Innovation Solution
A demodulator design that includes a sampler and a trigger unit, which samples a carrier signal with a predefined phase shift of 30° to 60° (plus an integer multiple of 90°) relative to zero crossings or extreme values, allowing for simultaneous capture of inphase and quadrature phase portions with sufficient signal quality, thereby reducing hardware complexity and eliminating the need for analog mixers and filters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate inphase and quadrature phase signal processing is used, then signal quality is maintained, but device complexity increases
Solution Approach 1:
The patent combines the functions of separate inphase and quadrature phase signal processing into a single sampling operation. By using a trigger unit to generate a trigger signal with a predefined phase shift (30° to 60° plus integer multiple of 90°) relative to the carrier signal, the sampler can simultaneously capture both inphase and quadrature phase information in one operation, eliminating the need for separate processing paths and reducing hardware complexity while maintaining signal quality.
2Reliability
If conventional demodulation methods are used, then signal processing is thorough, but manufacturing cost increases
Solution Approach 1:
The patent extracts and eliminates unnecessary hardware components from conventional demodulators. By using a trigger unit to generate appropriately phased trigger signals, the system removes the need for analog mixers and filters, which are typically required in conventional demodulation architectures. This extraction of unnecessary components reduces manufacturing cost while the predefined phase shift ensures thorough signal processing is maintained.
3Productivity
If high data rates are achieved, then productivity increases, but device complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-calculating and pre-setting the phase shift of the trigger signal to be between 30° to 60° plus an integer multiple of 90° relative to the carrier signal. This preliminary phase adjustment is done in advance through the trigger unit, which generates the trigger signal with the correct phase relationship before sampling occurs. This allows high data rates to be achieved without requiring complex real-time processing, as the phase relationship is established beforehand, thereby reducing chip set complexity while maintaining high productivity.
Data Source
AI summary
A demodulator includes a sampler and a trigger unit. The sampler is configured to sample a carrier signal based on a trigger signal to obtain a demodulated signal. The trigger unit is configured to detect a zero crossing of the carrier signal or an extreme value of an amplitude of the carrier signal. Further, the trigger unit is configured to provide the trigger signal based on the detected zero crossing or the detected extreme value, so that the carrier signal is sampled by the sampler with a predefined phase shift to the detected zero crossing or the detected extreme value. The predefined phase shift is larger than 30° plus an integer multiple of 90° and lower than 60° plus the same integer multiple of 90° in reference to the carrier signal.