Phase-Shifted RF Signal Approximation Under Time Quantization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional polar transmitters face challenges in minimizing out-of-band noise and spurious signal components due to time quantization, requiring sophisticated and power-consuming Digital-to-Time Converter (DTC) circuits, which affects the accuracy of RF signal generation in mobile communication systems.
Innovation Solution
An apparatus and method that approximate a first signal within a quantized time interval using a second signal by calculating and shifting the phase offset of the second signal to match the phase offset of the first signal, allowing for high-accuracy RF signal generation without the need for complex DTC circuits, thereby reducing power consumption and improving signal accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a large time quantization is used in the polar transmitter, then the technical implementation is easier, but the out-of-band noise increases significantly
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing phase offset values in a lookup table before the actual signal generation process. The phase offset, which compensates for time quantization effects, is determined in advance based on the oscillation period and stored for quick retrieval during transmission, eliminating the need for complex real-time calculations.
Solution Approach 2:
The patent introduces an intermediary element - the phase offset - that mediates between the time quantization and the output signal. This phase offset acts as a compensation mechanism that bridges the gap caused by coarse time quantization, allowing the system to achieve fine timing accuracy without requiring fine time quantization hardware.
2Object-affected harmful factors
If a small time quantization is used in the polar transmitter, then the out-of-band noise is reduced, but the Digital-to-Time Converter circuits become sophisticated and power consuming
Solution Approach 1:
The patent uses copying by creating a lookup table that stores pre-calculated phase offset values. Instead of performing complex real-time calculations to determine the phase offset, the system copies the appropriate pre-computed value from the lookup table based on the oscillation period, significantly reducing the computational burden and power consumption.
Solution Approach 2:
The patent replaces expensive, power-consuming sophisticated Digital-to-Time Converter circuits with a simple lookup table implementation. The lookup table is a low-cost, static data structure that requires minimal processing power to query, effectively substituting complex hardware with a simple data retrieval operation.
3Ease of operation
If periodic time quantization is used in the polar transmitter, then the implementation is straightforward, but spurious signal components appear in the output RF signal
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the phase offset parameter based on the oscillation period. The phase offset is calculated and stored as a function of the oscillation period, allowing the system to adapt to different input signal characteristics. This parameter adjustment eliminates the periodic pattern that causes spurious components while maintaining implementation simplicity.
4Measurement precision
If phase offset calculation and shifting is performed for each quantized time interval, then the approximation accuracy of the RF signal is improved, but the processing complexity increases
Solution Approach 1:
The patent resolves this contradiction by performing the complex phase offset calculation in advance and storing the results in a lookup table. During actual signal generation, the system only needs to retrieve the pre-calculated phase offset value corresponding to the current oscillation period, maintaining high approximation accuracy while minimizing real-time processing complexity.
Data Source
Figure 1
Figure 2a~2c
Figure 2d~2e
AI summary
A method for approximating a first signal having a first oscillation period within a quantized time interval using a second signal is provided. The second signal has a second oscillation period. The method includes calculating a phase offset of the first signal at at least one position within the quantized time interval. Further, the method comprises shifting the second signal within the quantized time interval until a phase offset of the second signal at the at least one position satisfies a quality criterion related to the phase offset of the first signal.