AMR Reduction Circuit Adaptive Threshold Signal Processing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current communications transmitters, particularly those using quadrature-modulator-based systems, face challenges in reducing the average-to-minimum magnitude ratio (AMR) of signals, which leads to high-frequency events and energy inefficiency, especially when handling non-constant envelope modulation schemes, making it difficult to comply with noise restriction standards.
Innovation Solution
The implementation of an adaptive hole blowing method that adjusts a time-varying low-magnitude threshold based on the symbols or samples of the baseband signal to reduce the AMR, using a symbol mapper, pulse-shaping filter, and AMR reduction circuit, allowing for dynamic modification of the baseband signal to minimize high-frequency content.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a fixed low-magnitude threshold is used for hole blowing, then the AMR is reduced, but the complexity increases and adaptability to different modulation schemes decreases
Solution Approach 1:
The patent implements a time-varying threshold that adapts dynamically based on signal conditions and modulation scheme characteristics. The threshold evolves over time rather than remaining fixed, allowing the system to optimize AMR reduction for different modulation schemes (QPSK, 16QAM, 64QAM, etc.) without requiring manual reconfiguration or complex threshold management.
2Object-affected harmful factors
If hole blowing is applied to reduce AMR, then high-frequency events are reduced, but the device complexity increases
Solution Approach 1:
The patent extracts and removes problematic high-frequency events from the signal by applying hole blowing selectively. The AMR reduction circuit identifies and modifies signal portions that cause high-frequency events while preserving the essential information content, thereby reducing harmful high-frequency content without requiring complete signal reconstruction or complex processing of the entire signal.
3Ease of manufacture
If conventional hole blowing with fixed threshold is used, then implementation is simple, but compliance with noise restriction standards across multiple systems is difficult
Solution Approach 1:
The patent creates a universal AMR reduction solution that works across multiple communication systems and modulation schemes. The time-varying threshold mechanism provides a single unified approach that adapts to different standards (W-CDMA, CDMA2000, GSM, EDGE, etc.) and modulation types, eliminating the need for separate implementations for each system while maintaining compliance with their respective noise restriction standards.
Data Source
AI summary
A communications transmitter configured to reduce the average-to-minimum magnitude ratio (AMR) of a communications signal includes a symbol mapper, a pulse-shaping filter, an AMR reduction circuit, and a modulator. The symbol mapper operates to generate a sequence of symbols from a binary-source data stream containing a message to be transmitted, and the pulse-shaping filter generates a baseband signal based on the sequence of symbols. The AMR reduction circuit is configured to compare magnitudes of samples of the baseband signal to a time-varying low-magnitude threshold, and modify the baseband signal to produce a modified baseband signal having a reduced AMR if a sample of the baseband signal is determined to have a magnitude less than the time-varying low-magnitude threshold. Finally, the modulator operates to modulate a carrier signal based on the modulation information contained in the modified baseband signal.